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Sample records for lt fountain codes

  1. Prioritized LT Codes

    NASA Technical Reports Server (NTRS)

    Woo, Simon S.; Cheng, Michael K.

    2011-01-01

    The original Luby Transform (LT) coding scheme is extended to account for data transmissions where some information symbols in a message block are more important than others. Prioritized LT codes provide unequal error protection (UEP) of data on an erasure channel by modifying the original LT encoder. The prioritized algorithm improves high-priority data protection without penalizing low-priority data recovery. Moreover, low-latency decoding is also obtained for high-priority data due to fast encoding. Prioritized LT codes only require a slight change in the original encoding algorithm, and no changes at all at the decoder. Hence, with a small complexity increase in the LT encoder, an improved UEP and low-decoding latency performance for high-priority data can be achieved. LT encoding partitions a data stream into fixed-sized message blocks each with a constant number of information symbols. To generate a code symbol from the information symbols in a message, the Robust-Soliton probability distribution is first applied in order to determine the number of information symbols to be used to compute the code symbol. Then, the specific information symbols are chosen uniform randomly from the message block. Finally, the selected information symbols are XORed to form the code symbol. The Prioritized LT code construction includes an additional restriction that code symbols formed by a relatively small number of XORed information symbols select some of these information symbols from the pool of high-priority data. Once high-priority data are fully covered, encoding continues with the conventional LT approach where code symbols are generated by selecting information symbols from the entire message block including all different priorities. Therefore, if code symbols derived from high-priority data experience an unusual high number of erasures, Prioritized LT codes can still reliably recover both high- and low-priority data. This hybrid approach decides not only "how to encode

  2. Compressed image transmission based on fountain codes

    NASA Astrophysics Data System (ADS)

    Wu, Jiaji; Wu, Xinhong; Jiao, L. C.

    2011-11-01

    In this paper, we propose a joint source-channel coding (JSCC) scheme for image transmission over wireless channel. In the scheme, fountain codes are integrated into bit-plane coding for channel coding. Compared to traditional erasure codes for error correcting, such as Reed-Solomon codes, fountain codes are rateless and can generate sufficient symbols on the fly. Two schemes, the EEP (Equal Error Protection) scheme and the UEP (Unequal Error Protection) scheme are described in the paper. Furthermore, the UEP scheme performs better than the EEP scheme. The proposed scheme not only can adaptively adjust the length of fountain codes according to channel loss rate but also reconstruct image even on bad channel.

  3. FOG: Fighting the Achilles' Heel of Gossip Protocols with Fountain Codes

    NASA Astrophysics Data System (ADS)

    Champel, Mary-Luc; Kermarrec, Anne-Marie; Le Scouarnec, Nicolas

    Gossip protocols are well known to provide reliable and robust dissemination protocols in highly dynamic systems. Yet, they suffer from high redundancy in the last phase of the dissemination. In this paper, we combine fountain codes (rateless erasure-correcting codes) together with gossip protocols for a robust and fast content dissemination in large-scale dynamic systems. The use of fountain enables to eliminate the unnecessary redundancy of gossip protocols. We propose the design of FOG, which fully exploits the first exponential growth phase (where the data is disseminated exponentially fast) of gossip protocols while avoiding the need for the shrinking phase by using fountain codes. FOG voluntarily increases the number of disseminations but limits those disseminations to the exponential growth phase. In addition, FOG creates a split-graph overlay that splits the peers between encoders and forwarders. Forwarder peers become encoders as soon as they have received the whole content. In order to benefit even further and quicker from encoders, FOG biases the dissemination towards the most advanced peers to make them complete earlier.

  4. On the Energy Efficiency of LT Codes in Proactive Wireless Sensor Networks

    NASA Astrophysics Data System (ADS)

    Abouei, Jamshid; Brown, J. David; Plataniotis, Konstantinos N.; Pasupathy, Subbarayan

    2011-03-01

    This paper presents an in-depth analysis on the energy efficiency of Luby Transform (LT) codes with Frequency Shift Keying (FSK) modulation in a Wireless Sensor Network (WSN) over Rayleigh fading channels with pathloss. We describe a proactive system model according to a flexible duty-cycling mechanism utilized in practical sensor apparatus. The present analysis is based on realistic parameters including the effect of channel bandwidth used in the IEEE 802.15.4 standard, active mode duration and computation energy. A comprehensive analysis, supported by some simulation studies on the probability mass function of the LT code rate and coding gain, shows that among uncoded FSK and various classical channel coding schemes, the optimized LT coded FSK is the most energy-efficient scheme for distance d greater than the pre-determined threshold level d_T , where the optimization is performed over coding and modulation parameters. In addition, although the optimized uncoded FSK outperforms coded schemes for d < d_T , the energy gap between LT coded and uncoded FSK is negligible for d < d_T compared to the other coded schemes. These results come from the flexibility of the LT code to adjust its rate to suit instantaneous channel conditions, and suggest that LT codes are beneficial in practical low-power WSNs with dynamic position sensor nodes.

  5. A hybrid quantum key distribution protocol based on extended unitary operations and fountain codes

    NASA Astrophysics Data System (ADS)

    Lai, Hong; Xue, Liyin; Orgun, Mehmet A.; Xiao, Jinghua; Pieprzyk, Josef

    2015-02-01

    In 1984, Bennett and Brassard designed the first quantum key distribution protocol, whose security is based on quantum indeterminacy. Since then, there has been growing research activities, aiming in designing new, more efficient and secure key distribution protocols. The work presents a novel hybrid quantum key distribution protocol. The key distribution is derived from both quantum and classical data. This is why it is called hybrid. The protocol applies extended unitary operations derived from four basic unitary operations and distributed fountain codes. Compared to other protocols published so far, the new one is more secure (provides authentication of parties and detection of eavesdropping) and efficient. Moreover, our protocol still works over noisy and lossy channels.

  6. SWAAM-LT: The long-term, sodium/water reaction analysis method computer code

    SciTech Connect

    Shin, Y.W.; Chung, H.H.; Wiedermann, A.H.; Tanabe, H.

    1993-01-01

    The SWAAM-LT Code, developed for analysis of long-term effects of sodium/water reactions, is discussed. The theoretical formulation of the code is described, including the introduction of system matrices for ease of computer programming as a general system code. Also, some typical results of the code predictions for available large scale tests are presented. Test data for the steam generator design with the cover-gas feature and without the cover-gas feature are available and analyzed. The capabilities and limitations of the code are then discussed in light of the comparison between the code prediction and the test data.

  7. Designing an efficient LT-code with unequal error protection for image transmission

    NASA Astrophysics Data System (ADS)

    S. Marques, F.; Schwartz, C.; Pinho, M. S.; Finamore, W. A.

    2015-10-01

    The use of images from earth observation satellites is spread over different applications, such as a car navigation systems and a disaster monitoring. In general, those images are captured by on board imaging devices and must be transmitted to the Earth using a communication system. Even though a high resolution image can produce a better Quality of Service, it leads to transmitters with high bit rate which require a large bandwidth and expend a large amount of energy. Therefore, it is very important to design efficient communication systems. From communication theory, it is well known that a source encoder is crucial in an efficient system. In a remote sensing satellite image transmission, this efficiency is achieved by using an image compressor, to reduce the amount of data which must be transmitted. The Consultative Committee for Space Data Systems (CCSDS), a multinational forum for the development of communications and data system standards for space flight, establishes a recommended standard for a data compression algorithm for images from space systems. Unfortunately, in the satellite communication channel, the transmitted signal is corrupted by the presence of noise, interference signals, etc. Therefore, the receiver of a digital communication system may fail to recover the transmitted bit. Actually, a channel code can be used to reduce the effect of this failure. In 2002, the Luby Transform code (LT-code) was introduced and it was shown that it was very efficient when the binary erasure channel model was used. Since the effect of the bit recovery failure depends on the position of the bit in the compressed image stream, in the last decade many e orts have been made to develop LT-code with unequal error protection. In 2012, Arslan et al. showed improvements when LT-codes with unequal error protection were used in images compressed by SPIHT algorithm. The techniques presented by Arslan et al. can be adapted to work with the algorithm for image compression

  8. Molecular fountain.

    SciTech Connect

    Strecker, Kevin E.; Chandler, David W.

    2009-09-01

    A molecular fountain directs slowly moving molecules against gravity to further slow them to translational energies that they can be trapped and studied. If the molecules are initially slow enough they will return some time later to the position from which they were launched. Because this round trip time can be on the order of a second a single molecule can be observed for times sufficient to perform Hz level spectroscopy. The goal of this LDRD proposal was to construct a novel Molecular Fountain apparatus capable of producing dilute samples of molecules at near zero temperatures in well-defined user-selectable, quantum states. The slowly moving molecules used in this research are produced by the previously developed Kinematic Cooling technique, which uses a crossed atomic and molecular beam apparatus to generate single rotational level molecular samples moving slowly in the laboratory reference frame. The Kinematic Cooling technique produces cold molecules from a supersonic molecular beam via single collisions with a supersonic atomic beam. A single collision of an atom with a molecule occurring at the correct energy and relative velocity can cause a small fraction of the molecules to move very slowly vertically against gravity in the laboratory. These slowly moving molecules are captured by an electrostatic hexapole guiding field that both orients and focuses the molecules. The molecules are focused into the ionization region of a time-of-flight mass spectrometer and are ionized by laser radiation. The new molecular fountain apparatus was built utilizing a new design for molecular beam apparatus that has allowed us to miniaturize the apparatus. This new design minimizes the volumes and surface area of the machine allowing smaller pumps to maintain the necessary background pressures needed for these experiments.

  9. Fountain rainbows.

    PubMed

    Gedzelman, Stanley David; Hernández-Andrés, Javier

    2008-12-01

    We present the first measurements of radiance spectra of rainbows. The bows on two sunny days (3 and 6 June 2008) were produced by the fountain in the Parque de las Ciencias, Granada, Spain, that consists of a rectangular perimeter of 40 spray nozzles. Optical thickness of the spray from each nozzle was approximately 0.5. Spectral purity of the primary bow was highest for orange and blue, reaching values of 23% and 7%, respectively, while skylight 90 degrees from the Sun had a color purity of 34% (on 6 June). The secondary bow had much lower color purity with red absent because the regions around the bows and in Alexander's dark band were pale blue. The narrow sickle shape of the chromaticity curves for the primary bows and the absence of supernumerary bows indicated that the drop radius was between 0.2 and 0.4 mm. PMID:19037346

  10. Convolutional fountain distribution over fading wireless channels

    NASA Astrophysics Data System (ADS)

    Usman, Mohammed

    2012-08-01

    Mobile broadband has opened the possibility of a rich variety of services to end users. Broadcast/multicast of multimedia data is one such service which can be used to deliver multimedia to multiple users economically. However, the radio channel poses serious challenges due to its time-varying properties, resulting in each user experiencing different channel characteristics, independent of other users. Conventional methods of achieving reliability in communication, such as automatic repeat request and forward error correction do not scale well in a broadcast/multicast scenario over radio channels. Fountain codes, being rateless and information additive, overcome these problems. Although the design of fountain codes makes it possible to generate an infinite sequence of encoded symbols, the erroneous nature of radio channels mandates the need for protecting the fountain-encoded symbols, so that the transmission is feasible. In this article, the performance of fountain codes in combination with convolutional codes, when used over radio channels, is presented. An investigation of various parameters, such as goodput, delay and buffer size requirements, pertaining to the performance of fountain codes in a multimedia broadcast/multicast environment is presented. Finally, a strategy for the use of 'convolutional fountain' over radio channels is also presented.

  11. Carbon Dioxide Fountain

    ERIC Educational Resources Information Center

    Kang, Seong-Joo; Ryu, Eun-Hee

    2007-01-01

    This article presents the development of a carbon dioxide fountain. The advantages of the carbon dioxide fountain are that it is odorless and uses consumer chemicals. This experiment also is a nice visual experiment that allows students to see evidence of a gaseous reagent being consumed when a pressure sensor is available. (Contains 3 figures.)…

  12. Multi-jurisdictional investigation of interactive fountain-associated cryptosporidiosis and salmonellosis outbreaks.

    PubMed

    Kirian, M L; Meregillano, G; Gennette, D; Weintraub, J M

    2008-11-01

    Interactive water fountains are established sources of gastrointestinal infections yet most health codes fail to regulate their design and operation. This report describes multi-agency, concurrent interactive fountain-associated cryptosporidiosis and salmonellosis outbreak investigations and highlights the need for the adoption of appropriate regulations for interactive fountains. PMID:18838018

  13. Multi-jurisdictional investigation of interactive fountain-associated cryptosporidiosis and salmonellosis outbreaks

    PubMed Central

    KIRIAN, M. L.; MEREGILLANO, G.; GENNETTE, D.; WEINTRAUB, J. M.

    2008-01-01

    Summary Interactive water fountains are established sources of gastrointestinal infections yet most health codes fail to regulate their design and operation. This report describes multi-agency, concurrent interactive fountain-associated cryptosporidiosis and salmonellosis outbreak investigations and highlights the need for the adoption of appropriate regulations for interactive fountains. PMID:18838018

  14. The USNO rubidium fountains

    NASA Astrophysics Data System (ADS)

    Peil, Steven; Hanssen, James; Swanson, Thomas B.; Taylor, Jennifer; Ekstrom, Christopher R.

    2016-06-01

    Four rubidium fountains at the U.S. Naval Observatory (USNO) have been in operation for 4.5 years. Each fountain has demonstrated periods of stability marked by Total or Theo deviation below 10‑16 Occasional frequency changes, on order of 1.5 times per year per fountain, introduce deviations from white-frequency noise behavior. Averaged together, the four fountains form an ensemble with a white-frequency noise level of 10‑13 and excellent long-term stability as compared to the primary frequency standards contributing to TAI. Progress on using the clocks at USNO for improving limits on coupling of fundamental constants to gravity by measuring the universality of the gravitational redshift for different types of clocks is discussed.

  15. Laser Soap Fountain

    NASA Astrophysics Data System (ADS)

    Foley, Tyler; Pegram, Matthew; Jenkins, Zachary; Hester, Brooke C.; Burris, Jennifer L.

    2015-01-01

    We have developed an eye-catching demonstration that showcases a variety of physics topics from total internal reflection to electrostatics to non-Newtonian fluid dynamics, including the Kaye effect. The essential components of the demonstration include a vertical stream of liquid soap in which a laser pointer is internally reflected, and which subsequently hits an inclined plane. As the liquid soap, a non-Newtonian fluid, begins to accumulate into a pile, its shear properties change and the incoming fluid rebounds from the pile, forming striking parabolic arcs. We present here a readily reproducible and inexpensive version of a laser soap fountain.

  16. Margaret Fountaine: a lepidopterist remembered

    PubMed Central

    Waring, Sophie

    2015-01-01

    Margaret Fountaine (1862–1940) was a lepidopterist during a period of transition and professionalization in natural history. Over her lifespan she collected more than 22 000 butterflies, published extensively and wrote a diary of more than a million words. Wealthy and independent, Fountaine toured Europe in her early twenties and then, over the next 50 years, travelled the globe collecting butterflies. Fountaine straddles many of the boundaries that historians have constructed to aid understanding of natural history in this period, specifically those defining gender roles, the nature of scientific knowledge and the divide between amateur and professional. Fountaine reminds us that these categories are never a clear or perfect division and that the reality of natural history research and exchange was much more complex than these boundaries often allow for. Fountaine herself is under-researched and this article contains a useful account of her entomological career. PMID:26489183

  17. Quantum Fountain Unipolar Lasers

    NASA Astrophysics Data System (ADS)

    Julien, Francois H.

    2001-03-01

    There is a strong interest in the development of semiconductor lasers for long-wavelength infrared applications. In the 2-20 um band, the recent demonstration of Quantum Cascade (QC) unipolar lasers is already challenging the currently available technology relying on electron-hole radiative recombination in narrow-gap semiconductors. Recently, an alternate type of unipolar laser relying on intersubband emission, the so-called Quantum Fountain intersubband laser (QF) has been proposed and demonstrated. The active region consists of periods of two GaAs/AlGaAs coupled quantum wells exhibiting three bound electron states. Electrons are optically excited from the ground state to the upper state. The radiative intersubband transition to the intermediate state gives rise to the infrared emission. Population inversion as well as fast recycling of electrons into the ground state is provided by insuring a short lifetime of electrons in the intermediate state through an enhanced scattering with LO-phonons. Although their operation imposes an external pumping source, QF lasers offer the advantages of a simplified design, of less stringent material requirements and of low internal losses due to free-carrier absorption as compared to QC lasers. In the talk, we will review the latest developments on high-brightness QF unipolar lasers emitting in the 8-16 um band. We will show that record high optical powers and single-transverse mode operation can be achieved by designing broad-area lasers with a top grating [1]. Novel designs relying on superlattice active regions will also be discussed. [1] O. Gauthier-Lafaye, B. Seguin-Roa, F. H. Julien, G. Strasser, P. Collot, C. Sirtori, J.-Y. Duboz, Physica E 7, p.12 (2000).

  18. LT25, LT50, and LT75 determinations for a diverse selection of vaccinium genotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Freeze-bath cold hardiness results were used to calculate LT25 and LT75 values (temperatures causing 25% and 75% lethality, respectively) for a diverse selection of Vaccinium genotypes which had been previously analyzed for LT50 values. Overall, LT25 and LT75 values paralleled the LT50 values. Acros...

  19. Energy efficient rateless codes for high speed data transfer over free space optical channels

    NASA Astrophysics Data System (ADS)

    Prakash, Geetha; Kulkarni, Muralidhar; Acharya, U. S.

    2015-03-01

    Terrestrial Free Space Optical (FSO) links transmit information by using the atmosphere (free space) as a medium. In this paper, we have investigated the use of Luby Transform (LT) codes as a means to mitigate the effects of data corruption induced by imperfect channel which usually takes the form of lost or corrupted packets. LT codes, which are a class of Fountain codes, can be used independent of the channel rate and as many code words as required can be generated to recover all the message bits irrespective of the channel performance. Achieving error free high data rates with limited energy resources is possible with FSO systems if error correction codes with minimal overheads on the power can be used. We also employ a combination of Binary Phase Shift Keying (BPSK) with provision for modification of threshold and optimized LT codes with belief propagation for decoding. These techniques provide additional protection even under strong turbulence regimes. Automatic Repeat Request (ARQ) is another method of improving link reliability. Performance of ARQ is limited by the number of retransmissions and the corresponding time delay. We prove through theoretical computations and simulations that LT codes consume less energy per bit. We validate the feasibility of using energy efficient LT codes over ARQ for FSO links to be used in optical wireless sensor networks within the eye safety limits.

  20. Maximizing the Spectacle of Water Fountains

    ERIC Educational Resources Information Center

    Simoson, Andrew J.

    2009-01-01

    For a given initial speed of water from a spigot or jet, what angle of the jet will maximize the visual impact of the water spray in the fountain? This paper focuses on fountains whose spigots are arranged in circular fashion, and couches the measurement of the visual impact in terms of the surface area and the volume under the fountain's natural…

  1. A comparative analysis of XV-15 tiltrotor hover test data and WOPWOP predictions incorporating the fountain effect

    NASA Technical Reports Server (NTRS)

    Rutledge, Charles K.; Coffen, Charles D.; George, Albert R.

    1991-01-01

    Acoustic measurements from a hovering full scale XV-15 tilt rotor with the advanced technology blades are presented which show the directionality of fountain effect noise. Predicted acoustic directivity results are also presented which show agreement with the measured data. The aeroacoustic code, WOPWOP, was used in conjunction with a mathematical model which simulated the fountain recirculation aerodynamic effect on the rotor blade surface pressures. The predictions were used to identify the spike character in the measured data as fountain effect associated noise. The directivity of the fountain effect noise was observed to be dominant at the rear of the aircraft with increased intensities 45 degrees below the rotor disk planes.

  2. Galactic Fountains and Gas Accretion

    NASA Astrophysics Data System (ADS)

    Marinacci, F.; Binney, J.; Fraternali, F.; Nipoti, C.; Ciotti, L.; Londrillo, P.

    2010-06-01

    Star-forming disc galaxies such as the Milky Way need to accrete >~1 Msolar of gas each year to sustain their star formation. This gas accretion is likely to come from the cooling of the hot corona, however it is still not clear how this process can take place. We present simulations supporting the idea that this cooling and the subsequent accretion are caused by the passage of cold galactic-fountain clouds through the hot corona. The Kelvin-Helmholtz instability strips gas from these clouds and the stripped gas causes coronal gas to condense in the cloud's wake. For likely parameters of the Galactic corona and of typical fountain clouds we obtain a global accretion rate of the order of that required to feed the star formation.

  3. 2. Fountain without its gazebo, taken February 16, 1961, eight ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Fountain without its gazebo, taken February 16, 1961, eight years before its removal. Photographed by Jack E. Boucher. - Sons of Temperance Fountain, Independence Square (moved from Centennial Exhibition grounds at Belmont & Fountain Avenues), Philadelphia, Philadelphia County, PA

  4. Delayed-onset cytomegalovirus disease coded during hospital readmission in a multicenter retrospective cohort of liver transplant recipients (Manuscript ID LT-14-570)

    PubMed Central

    Santos, Carlos A. Q.; Brennan, Daniel C.; Chapman, William C.; Fraser, Victoria J.; Olsen, Margaret A.

    2015-01-01

    Background Delayed-onset cytomegalovirus (CMV) disease can occur among liver transplant recipients after stopping CMV prophylaxis. We hypothesized that delayed-onset CMV disease (> 100 days post-transplant) occurs more commonly than early-onset CMV disease and is associated with clinical sepsis and death. Methods We assembled a large and more representative cohort of 7,229 adult liver transplant recipients from 26 transplant centers using 2004 to 2010 ICD-9-CM billing data from 4 Healthcare Cost and Utilization Project State Inpatient Databases, and identified demographics, comorbidities, CMV disease and clinical sepsis coded during readmission, and inpatient death. Multivariate analysis was performed using Cox proportional hazards models. Results Delayed-onset CMV disease occurred in 4.3% (n=309), while early-onset CMV disease occurred in 2% (n=142). Delayed-onset CMV disease was associated with previous transplant failure or rejection (aHR 1.4, 95% CI 1.1-1.7). Clinical sepsis > 100 days post-transplant was associated with previous CMV disease (aHR 1.3, 95% CI 1.0-1.7), previous transplant failure or rejection (aHR 2.1, 95% CI 1.8-2.4), female sex (aHR 1.3, 95% CI 1.1-1.5) and several comorbidities. Death > 100 days post-transplant was associated with delayed-onset CMV disease (aHR 2.0, 95% CI 1.6-2.6), transplant failure or rejection (aHR 4.3, 95% CI 3.4-5.5), increasing age (by decade: aHR 1.1, 95% CI 1.0-1.2) and some comorbidities. Conclusions Delayed-onset CMV disease is more common than early-onset CMV disease among liver transplant recipients. Previous CMV disease may be a risk factor for clinical sepsis > 100 days post-transplant, and delayed-onset CMV disease may be a risk factor for death > 100 days post-transplant. PMID:25678072

  5. LT-HSC Methylcellulose Assay

    PubMed Central

    Kerenyi, Marc A.

    2016-01-01

    Hematopoietic differentiation is a highly complex process originating from an extraordinary population of cells called long-term repopulating hematopoietic stem cells (LT-HSCs). The unique feature of all stem cells, including HSCs, is their exceptional ability to divide asymmetrically giving rise to two different kinds of offspring. One daughter cell becomes an LT-HSC itself (self-renews) to maintain the LT-HSC pool, whereas the second daughter cell pursues a differentiation fate to ultimately give rise to terminally differentiated mature blood cells (Orkin and Zon, 2008). Quantification of phenotypic LT-HSCs can be performed by multi-color flow cytometry and the gold standard for assessment of LT-HSC self-renewal and function is competitive bone marrow transplantation (Miller et al., 2008). Although these methods are irreplaceable to determine LT-HSC abundance and functionality, they have their disadvantages and limitations. For example, competitive bone marrow transplantation is typically monitored as a function of peripheral blood donor contribution over 12–16 weeks. While reduced peripheral blood donor contribution by itself signifies impairment in the stem/progenitor cells compartment, it cannot unambiguously discriminate between reduced LT-HSC self-renewal, impaired LT-HSC differentiation or compromised progenitor cell differentiation. Here we describe an LT-HSCs methylcellulose colony-forming assay, as a fast complementary in vitro method to directly assess LT-HSC differentiation capacity. As described in Kerenyi et al. (2013), this technique acts as a powerful tool to differentiate between LT-HSC or progenitor cell differentiation defects.

  6. Is there a stratospheric fountain?

    NASA Astrophysics Data System (ADS)

    Pommereau, J.-P.; Held, G.

    2007-06-01

    of convective overshoots as proposed by Danielsen (1982) do not appear as episodic isolated features, but common and systematic events over a land convective area, that is a Stratospheric Fountain. Though the two-stages process proposed by Sherwood (2000) may also be operative, it offers a mechanism for producing the chemical, moisture and thermal properties observed in the stratosphere. The consistency between convective cooling of the TTL and weather radar echoes heights observed during the summer over South-East Brazil and the TRMM radar OPFs and LIS lightning events maximum frequencies, the latter showing also maximum events over Africa, South-East Asia, the Indonesian Islands and Northern Australia depending on the season (Liu and Zipser, 2005), suggests the existence of several "Stratospheric Fountains" over continents instead of the oceanic area of Micronesia as proposed by Newell and Gould-Stewart (1982), which appears a region of little overshoot.

  7. 2. Photocopy of the fountain in front of Philadelphia Museum ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Photocopy of the fountain in front of Philadelphia Museum of Art, ca. 1928, courtesy of Philadelphia Museum of Art - Fountain of the Sea Horses, Aquarium Lane, Philadelphia, Philadelphia County, PA

  8. 1. FOUNTAIN IN FRONT (SOUTH) OF CLUBHOUSE. VIEW TO SOUTHWEST. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. FOUNTAIN IN FRONT (SOUTH) OF CLUBHOUSE. VIEW TO SOUTHWEST. - Rainbow Hydroelectric Facility, Fountain, On north bank of Missouri River 2 miles Northeast of Great Falls, & end of Rainbow Dam Road, Great Falls, Cascade County, MT

  9. Physics of the granite sphere fountain

    NASA Astrophysics Data System (ADS)

    Snoeijer, Jacco H.; der Weele, Ko van

    2014-11-01

    A striking example of levitation is encountered in the "kugel fountain" where a granite sphere, sometimes weighing over a ton, is kept aloft by a thin film of flowing water. In this paper, we explain the working principle behind this levitation. We show that the fountain can be viewed as a giant ball bearing and thus forms a prime example of lubrication theory. It is demonstrated how the viscosity and flow rate of the fluid determine (i) the remarkably small thickness of the film supporting the sphere and (ii) the surprisingly long time it takes for rotations to damp out. The theoretical results compare well with measurements on a fountain holding a granite sphere of one meter in diameter. We close by discussing several related cases of levitation by lubrication.

  10. Legionellosis Outbreak Associated With a Hotel Fountain

    PubMed Central

    Smith, Shamika S.; Ritger, Kathy; Samala, Usha; Black, Stephanie R.; Okodua, Margaret; Miller, Loretta; Kozak-Muiznieks, Natalia A.; Hicks, Lauri A.; Steinheimer, Craig; Ewaidah, Saadeh; Presser, Lance; Siston, Alicia M.

    2015-01-01

    Background. In August 2012, the Chicago Department of Public Health (CDPH) was notified of acute respiratory illness, including 1 fatality, among a group of meeting attendees who stayed at a Chicago hotel during July 30–August 3, 2012. Suspecting Legionnaires' disease (LD), CDPH advised the hotel to close their swimming pool, spa, and decorative lobby fountain and began an investigation. Methods. Case finding included notification of individuals potentially exposed during July 16–August 15, 2012. Individuals were interviewed using a standardized questionnaire. An environmental assessment was performed. Results. One hundred fourteen cases were identified: 11 confirmed LD, 29 suspect LD, and 74 Pontiac fever cases. Illness onsets occurred July 21–August 22, 2012. Median age was 48 years (range, 22–82 years), 64% were male, 59% sought medical care (15 hospitalizations), and 3 died. Relative risks for hotel exposures revealed that persons who spent time near the decorative fountain or bar, both located in the lobby were respectively 2.13 (95%, 1.64–2.77) and 1.25 (95% CI, 1.09–1.44) times more likely to become ill than those who did not. Legionella pneumophila serogroup 1 was isolated from samples collected from the fountain, spa, and women's locker room fixtures. Legionella pneumophila serogroup 1 environmental isolates and a clinical isolate had matching sequence-based types. Hotel maintenance records lacked a record of regular cleaning and disinfection of the fountain. Conclusions. Environmental testing identified Legionella in the hotel's potable water system. Epidemiologic and laboratory data indicated the decorative fountain as the source. Poor fountain maintenance likely created favorable conditions for Legionella overgrowth. PMID:26716104

  11. 46 CFR 153.216 - Shower and eyewash fountains.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Vessel Requirements § 153.216 Shower and eyewash fountains. (a) Each non-self-propelled ship must have a fixed or portable shower and eyewash fountain that operates during cargo transfer and meets paragraph (c... 46 Shipping 5 2010-10-01 2010-10-01 false Shower and eyewash fountains. 153.216 Section...

  12. Systematic Effects in Atomic Fountain Clocks

    NASA Astrophysics Data System (ADS)

    Gibble, Kurt

    2016-06-01

    We describe recent advances in the accuracies of atomic fountain clocks. New rigorous treatments of the previously large systematic uncertainties, distributed cavity phase, microwave lensing, and background gas collisions, enabled these advances. We also discuss background gas collisions of optical lattice and ion clocks and derive the smooth transition of the microwave lensing frequency shift to photon recoil shifts for large atomic wave packets.

  13. Department of Amplification: The Perpetual Salt Fountain.

    ERIC Educational Resources Information Center

    Arons, Arnold B.

    1995-01-01

    Presents the story of "The Perpetual Salt Fountain" to illustrate some fairly typical ramifications and vagaries in the workings of science. Outlines the discovery of double diffusive convection and uses the fact that it had been observed in the laboratory a century before its independent rediscovery to emphasize the vagaries of discovery. (23…

  14. Radiative heating rates near the stratospheric fountain

    NASA Technical Reports Server (NTRS)

    Doherty, G. M.; Newell, R. E.; Danielsen, E. F.

    1984-01-01

    Radiative heating rates are computed for various sets of conditions thought to be appropriate to the stratospheric fountain region: with and without a layer of cirrus cloud between 100 and 150 mbar; with standard ozone and with decreased ozone in the lower stratosphere, again with and without the cirrus cloud; and with different temperatures in the tropopause region. The presence of the cloud decreases the radiative cooling below the cloud in the upper troposphere and increases the cooling above it in the lower stratosphere. The cloud is heated at the base and cooled at the top and thus radiatively destabilized; overall it gains energy by radiation. Decreasing ozone above the cloud also tends to cool the lower stratosphere. The net effect is a tendency for vertical convergence and horizontal divergence in the cloud region. High resolution profiles of temperature, ozone, and cloudiness within the fountain region are required in order to assess the final balance of the various processes.

  15. A distinctive type of ascending prominence - 'Fountain'

    NASA Technical Reports Server (NTRS)

    Tandberg-Hanssen, E.; Hansen, R. T.; Riddle, A. C.

    1975-01-01

    Cinematographic observations of solar prominences made at Mauna Loa, Hawaii, during the past few years suggest that there is a well-defined subclass of ascending prominences characterized by closed-system transference of chromospheric material along an arch or loop (up one leg and down the other). While this occurs, the entire prominence envelope steadily rises upward and expands through the corona. These prominences are denoted as 'fountains'. Several examples are described. Fountains appear to be well contained by coronal magnetic fields. Their total kinetic energy is of the order of 10 to the 30th power erg, but dissipation is typically quite slow (over time periods of 100 min or so), so that the correlative disturbances (radio bursts, coronal transients, chromospheric brightenings) are generally not spectacular or nonexistent.

  16. Can soda fountains be recommended in hospitals?

    PubMed

    Chaberny, Iris F; Kaiser, Peter; Sonntag, Hans-Günther

    2006-09-01

    Mineral water (soda water) is very popular in Germany. Therefore, soda fountains were developed as alternatives to the traditional deposit bottle system. Nowadays, different systems of these devices are commercially available. For several years, soda fountains produced by different companies have been examined at the University Hospital of Heidelberg. In 1998, it was possible for the first time to observe and evaluate one of these systems over a period of 320 days in a series of microbiological examinations. The evaluation was implemented on the basis of the German drinking water regulation (Anonymous, 1990. Gesetz über Trinkwasser und Wasser für Lebensmittelbetriebe (Trinkwasserverordnung - TrinkwV) vom 12. Dezember 1990. Bundesgesetzblatt 66, 2613ff). Initially, the bacteria counts exceeded the reference values imposed by the German drinking water regulation in almost 50% of the analyses. Pseudomonas aeruginosa was also detected in almost 38% of the samples. After a re-arrangement of the disinfection procedure and the removal of the charcoal filter, Pseudomonas aeruginosa was not detectable any more. However, the bacteria counts still frequently exceeded the reference values of the German drinking water regulation. Following our long-term analysis, we would not recommend soda fountains in high-risk areas of hospitals. If these devices are to be used in hospitals, the disinfection procedures should be executed in weekly or fortnightly intervals and the water quality should be examined periodically. PMID:16740412

  17. Hydrogen masers and cesium fountains at NRC

    NASA Technical Reports Server (NTRS)

    Boulanger, J.-S.; Morris, D.; Douglas, R. J.; Gagne, M.-C.

    1994-01-01

    The NRC masers H-3 and H-4 have been operating since June 1993 with cavity servo control. These low-flux active H masers are showing stabilities of about 10(exp -15) from 1 hour to several days. Stability results are presented, and the current and planned uses of the masers are discussed. A cesium fountain primary frequency standard project has been started at NRC. Trapping and launching experiments with the goal of 7 m/s launches are beginning. We discuss our plans for a local oscillator and servo that exploit the pulsed aspect of cesium fountain standards, and meet the challenge of 10(exp -14) tau(exp -1/2) stability without requiring masers. At best, we expect to run this frequency standard initially for periods of hours each working day rather than continuously for years, and so frequency transfer to outside laboratories has been carefully considered. We conclude that masers (or other even better secondary clocks) are required to exploit this potential accuracy of the cesium fountain. We present and discuss our conclusion that it is feasible to transfer frequency in this way with a transfer-induced uncertainty of less than 10(exp -15), even in the presence of maser frequency drift and random walk noise.

  18. Concerns about infectious hepatitis and Delacorte's Welfare Island Fountain.

    PubMed

    Spiegel, Allen D; Kavaler, Florence; Metz, Arielle A

    2004-06-01

    In 1969, philanthropist George T. Delacorte donated a spectacular water fountain to New York City on the southern tip of Welfare Island. Architects designed the fountain's jet geyser to pump a plume of water from the East River more than 400 feet into the air. Public health experts feared that the water from the heavily polluted East River could be a possible source for the spread of infectious hepatitis. Water droplets could be airborne by the prevailing winds to land on the densely populated east side of Manhattan. Upon the insistence of the New York City Department of Health, the fountain's water intake source was chlorinated. This action was initiated before the discovery of the hepatitis A virus (HAV) in 1973. A miscellany of continuing problems plagued the fountain for about two decades, causing the donor to label the fountain "Delacorte's Folly." Eventually, Delacorte gave up. In the late 1980s, the fountain ceased spouting and was finally dismantled. PMID:15141899

  19. Accuracy Evaluation of NIM5 Cesium Fountain Clock

    NASA Astrophysics Data System (ADS)

    Liu, Nian-Feng; Fang, Fang; Chen, Wei-Liang; Lin, Ping-Wei; Wang, Ping; Liu, Kun; Suo, Rui; Li, Tian-Chu

    2013-01-01

    The NIM5 fountain clock is the second fountain clock built at NIM (National Institute of Metrology, China), and has been operating stably and sub-continually since 2008. The fountain operates with a simple one-stage optical molasses to collect cold atoms, which reduces the collisional frequency shift dramatically. The fractional frequency uncertainty is estimated to be 2 × 10-15. The typical frequency instability of 2.5 × 10-14 is obtained at 10 s. Comparisons with other fountain frequency standards worldwide demonstrate agreement within the stated uncertainties.

  20. Flattening Earth acceleration in atomic fountains

    SciTech Connect

    Bertoldi, Andrea

    2010-07-15

    A method to compensate for Earth's gravity tide over an extended axial region is reported. Flattening acceleration is important in experiments where the coupling of the dynamics of free-falling probes to the gravity gradient generates stochastic noise on the measurement. Optimized cylindrically symmetric mass distributions lower Earth's tidal effect over 10 cm by a factor 10{sup 3}. A multimass compensation system with comparable performance is devised for tall atom interferometers. Reducing the gravity gradient is essential in terrestrial experiments based on atom fountain configurations being developed to precisely test general relativity or the neutrality of matter.

  1. Simulation of the formation and characteristics of ultrasonic fountain.

    PubMed

    Xu, Zheng; Yasuda, Keiji; Liu, Xiaojun

    2016-09-01

    In order to design an ultrasonic apparatus with a high throughput rate for generating atomization, the mechanism of fountain characteristics is important because the throughput rate of the ultrasonic atomization is decided by the area of the fountain surface. The formation of the fountain can be numerically studied by taking into account the effect of surface tension and radiation pressure. We have investigated the shape of the fountain with different ultrasound parameters or different kinds of solutions. When the amplitude of input sound pressure is higher than 1.3×10(5)Pa, the liquid separates from the ultrasonic fountain after irradiation for a very short period. It is further found that the area of the fountain surface increases with the concentration of the ethanol due to its low surface tension, density and sound speed. Finally, we discuss the difference between the ultrasonic fountain and the pump fountain, and find that the velocity field in the reactor induced by the pump is higher than that by the ultrasound. PMID:27150767

  2. Benefit of combined triiodothyronine (LT(3)) and thyroxine (LT(4)) treatment in athyreotic patients unresponsive to LT(4) alone.

    PubMed

    Solter, D; Solter, M

    2012-02-01

    Despite some reports, the usefulness of levothyroxine (LT(4)) and levotriiodothyronine (LT(3)) combination therapy in hypothyroidism remains controversial. The objective of this paper is to study a benefit of additional LT(3) in athyreotic patients who failed to normalize TSH on LT(4) alone even with hyperthyroid serum T(4) values. In a survey of 200 athyreotic patients treated between 2006 and 2009, about 7% failed to normalize serum TSH levels following treatment with LT(4), though serum T(4) values in the hyperthyroid range were achieved. These patients (characterized by serum T(4)≥160 nmol/L and TSH≥5.0 mIU/L), were additionally treated with 10 μg b. i. d LT(3). LT(3) and LT(4) combination therapy resulted in decreased serum TSH levels into the normal range (12.8 vs. 1.22 mIU/L; p<0.01) and reduced LT(4) dose (153.3 vs. 117.5 μg; p<0.01) required for normalization of serum T(4) values (170.6 vs. 123.3 nmol/L; p<0.01). Serum T(3) values were higher (1.3 vs. 2.26 nmol/L; p<0.01) than those during monotherapy with LT(4). Our results indicate a subpopulation of athyreotic patients that could significantly benefit from combined LT(4) + LT(3) therapy in restoring normal TSH and thyroid hormone patterns. Further research should be undertaken to provide a genetic basis for these findings. PMID:22187290

  3. View looking down to the Oscar S. Straus Memorial Fountain. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View looking down to the Oscar S. Straus Memorial Fountain. The monument was authorized by Congress in 1927 and dedicated in 1947. It consists of the fountain and two groups of statues, Religious Freedom and Reason. It was disassembled in 1991 and reinstalled after the construction of the Ronald Reagan Building and the International Trade Center. The rededication took place in 1998 and the fountain is located near the west entrance of the building complex. - Ronald Reagan Building and International Trade Center, 1300 Pennsylvania Avenue, NW, Washington, District of Columbia, DC

  4. Performance of the PARCS Testbed Cesium Fountain Frequency Standard

    NASA Technical Reports Server (NTRS)

    Enzer, Daphna G.; Klipstein, William M.

    2004-01-01

    A cesium fountain frequency standard has been developed as a ground testbed for the PARCS (Primary Atomic Reference Clock in Space) experiment, an experiment intended to fly on the International Space Station. We report on the performance of the fountain and describe some of the implementations motivated in large part by flight considerations, but of relevance for ground fountains. In particular, we report on a new technique for delivering cooling and trapping laser beams to the atom collection region, in which a given beam is recirculated three times effectively providing much more optical power than traditional configurations. Allan deviations down to 10 have been achieved with this method.

  5. The fluid dynamics of the chocolate fountain

    NASA Astrophysics Data System (ADS)

    Townsend, Adam K.; Wilson, Helen J.

    2016-01-01

    We consider the fluid dynamics of the chocolate fountain. Molten chocolate is a mildly shear-thinning non-Newtonian fluid. Dividing the flow into three main domains—the pumped flow up the centre, the film flow over each dome, and the freely falling curtain flow between the domes—we generate a wide-ranging study of Newtonian and non-Newtonian fluid mechanics. The central pumped flow is a benchmark to elucidate the effects of shear-thinning. The dome flow can be modelled as a thin-film flow with the leading-order effects being a simple balance of gravity and viscosity. Finally, the curtain flow is analytically intractable but is related to the existing theory of water bells (both inviscid and viscous). In pipe flow, Newtonian fluids exhibit a parabolic velocity profile; shear-thinning makes the profile more blunted. In thin-film flow over the dome, gravitational and viscous effects balance and the dome shape is not important beyond the local slope. We find that the chocolate thins and slows down as it travels down the dome. Finally, in the curtain flow, we predict the shape of the falling sheet for an inviscid fluid, and compare this with the literature to predict the shape for a viscous fluid, having shown that viscous forces are too great to ignore. We also find that the primary effect driving the shape of the curtain (which falls inwards towards the axis of the fountain) is surface tension. We find that the three domains provide excellent introductions to non-Newtonian mechanics, the important mathematical technique of scaling, and how to manipulate existing data to make our own predictions. We also find that the topic generates interest among the public in our engagement work.

  6. Intensive Exercise a Fountain of Youth for Aging Muscles

    MedlinePlus

    ... Intensive Exercise a Fountain of Youth for Aging Muscles Study found muscle tissues of elderly athletes more robust and younger ... 6, 2016 (HealthDay News) -- One key to keeping muscles young is as close as the nearest gym, ...

  7. 19th Century Textbook Illustrations - XLI, Hero's Fountain.

    ERIC Educational Resources Information Center

    Greenslade, Thomas B.

    1982-01-01

    Presents background information on and instructions for constructing a Hero's water fountain. Includes photographs of the apparatus from old textbooks and one in the collection of the National Museum of History and Technology at the Smithsonian Institution. (SK)

  8. 1. EXTERIOR VIEW, FRONT (EAST) FACADE WITH FIVE POINTS FOUNTAIN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. EXTERIOR VIEW, FRONT (EAST) FACADE WITH FIVE POINTS FOUNTAIN (CENTER), DULION APARTMENTS AND ELEVENTH AVENUE SOUTH (RIGHT). VIEW TAKEN JUST AFTER BIRMINGHAM BLIZZARD OF 1993. - Highlands United Methodist Church, 1045 Twentieth Street South, Birmingham, Jefferson County, AL

  9. Cancellation of the Collisional Frequency Shift in Caesium Fountain Clocks

    SciTech Connect

    Szymaniec, K.; Chalupczak, W.; Tiesinga, E.; Williams, C. J.; Weyers, S.; Wynands, R.

    2007-04-13

    We have observed that the collisional frequency shift in primary caesium fountain clocks varies with the clock state population composition and, in particular, is zero for a given fraction of the |F=4,m{sub F}=0> atoms, depending on the initial cloud parameters. We present a theoretical model explaining our observations. The possibility of the collisional shift cancellation implies an improvement in the performance of caesium fountain standards and a simplification in their operation.

  10. Unsteady three-dimensional simulation of VTOL upwash fountain turbulence

    NASA Technical Reports Server (NTRS)

    Childs, Robert E.; Nixon, David

    1987-01-01

    Numerical simulations of a planar turbulent wall jet and a planar VTOL upwash fountain were performed. These are three dimensional simulations which resolve large scale unsteady motions in the flows. The wall jet simulation shows good agreement with experimental data and is presented to verify the simulation methodology. Simulation of the upwash fountain predicts elevated shear stress and a half velocity width spreading rate of 33% which agrees well with experiment. Turbulence mechanisms which contribute to the enhanced spreading rate are examined.

  11. Effects of either LT4 monotherapy or LT4/LT3 combined therapy in patients totally thyroidectomized for thyroid cancer.

    PubMed

    Regalbuto, Concetto; Maiorana, Raffaella; Alagona, Corradina; Paola, Roberto Di; Cianci, Michelangela; Alagona, Giovanna; Sapienza, Salvatore; Squatrito, Sebastiano; Pezzino, Vincenzo

    2007-04-01

    After total thyroidectomy all thyroid cancer patients require lifelong treatment with thyroid hormones; the treatment of choice is synthetic levothyroxine (LT4). The question of whether these patients might benefit from the combined LT4 and liothyronine (LT3) treatment has been addressed with conflicting conclusions. The aim of the present study was to compare the effects of combined low LT4/LT3 molar ratio therapy versus LT4 monotherapy on various target organs and tissues in patients thyroidectomized for thyroid cancer. Urine collection (24 hour), a fasting blood sample for laboratory examinations, thyroid function clinical score, and cardiovascular, neurological, and neuropsychological evaluations were obtained. Clinical parameters and peripheral markers of thyroid function were measured during the two different treatment regimens in 20 patients. Mean serum aspartate aminotransferase, alanine aminotransferase, sex hormone binding globulin, and osteocalcin values were significantly higher during the combined treatment. No significant differences in the clinical score, the systolic and diastolic performance, and the neurological and neuropsychological evaluations were observed between the two treatment regimens. Moreover, no alteration due to subclinical hyperthyroidism or to the fluctuations in serum T3 concentrations during the combined therapy was observed. In conclusion, we found no evidence that combined therapy with a low LT4/LT3 molar ratio resulted in improved well-being and cognitive function or in increased thyroid hormone action on peripheral tissues in respect to LT4 monotherapy. Until future large, blind, randomized, and controlled trials prove otherwise, LT4 should remain the standard treatment for thyroid cancer patients. PMID:17465862

  12. Mapping the magnetic field vector in a fountain clock

    SciTech Connect

    Gertsvolf, Marina; Marmet, Louis

    2011-12-15

    We show how the mapping of the magnetic field vector components can be achieved in a fountain clock by measuring the Larmor transition frequency in atoms that are used as a spatial probe. We control two vector components of the magnetic field and apply audio frequency magnetic pulses to localize and measure the field vector through Zeeman spectroscopy.

  13. Ultrasonic atomization of liquids in drop-chain acoustic fountains

    PubMed Central

    Simon, Julianna C.; Sapozhnikov, Oleg A.; Khokhlova, Vera A.; Crum, Lawrence A.; Bailey, Michael R.

    2015-01-01

    When focused ultrasound waves of moderate intensity in liquid encounter an air interface, a chain of drops emerges from the liquid surface to form what is known as a drop-chain fountain. Atomization, or the emission of micro-droplets, occurs when the acoustic intensity exceeds a liquid-dependent threshold. While the cavitation-wave hypothesis, which states that atomization arises from a combination of capillary-wave instabilities and cavitation bubble oscillations, is currently the most accepted theory of atomization, more data on the roles of cavitation, capillary waves, and even heat deposition or boiling would be valuable. In this paper, we experimentally test whether bubbles are a significant mechanism of atomization in drop-chain fountains. High-speed photography was used to observe the formation and atomization of drop-chain fountains composed of water and other liquids. For a range of ultrasonic frequencies and liquid sound speeds, it was found that the drop diameters approximately equalled the ultrasonic wavelengths. When water was exchanged for other liquids, it was observed that the atomization threshold increased with shear viscosity. Upon heating water, it was found that the time to commence atomization decreased with increasing temperature. Finally, water was atomized in an overpressure chamber where it was found that atomization was significantly diminished when the static pressure was increased. These results indicate that bubbles, generated by either acoustic cavitation or boiling, contribute significantly to atomization in the drop-chain fountain. PMID:25977591

  14. VIEW OF THE FOUNTAIN IN THE BANNEKER OVERLOOK DESIGNED BY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF THE FOUNTAIN IN THE BANNEKER OVERLOOK DESIGNED BY DAN URBAN KILEY AND COMPLETED AROUND 1968 - Southwest Washington, Urban Renewal Area, Bounded by Independence Avenue, Washington Avenue, South Capitol Street, Canal Street, P Street, Maine Avenue & Washington Channel, Fourteenth Street, D Street, & Twelfth Street, Washington, District of Columbia, DC

  15. The Ammonia Smoke Fountain: An Interesting Thermodynamic Adventure.

    ERIC Educational Resources Information Center

    Alexander, M. Dale

    1999-01-01

    Describes a new demonstration that uses an apparatus like the ammonia-fountain apparatus but with modifications designed to produce ammonium-chloride smoke. This demonstration is easy to perform, interesting to observe, and allows demonstration of the solubility of ammonia in water, the basic nature of ammonia, the acidic nature of hydrogen…

  16. HyBoLT Flight Experiment

    NASA Technical Reports Server (NTRS)

    Chen, Fang-Jeng (Frank); Berry, Scott A.

    2010-01-01

    HyBoLT was a Hypersonic Boundary Layer Transition flight experiment funded by the Hypersonics Project of the Fundamental Aeronautics Program in NASA's Aeronautics Research Mission Directorate. The HyBoLT test article mounted on the top of the ALV X-1 rocket was launched from Virginia's Wallops Island on August 22, 2008. Unfortunately a problem in the rocket's flight control system caused the vehicle to veer off the designed flight course. Launch officials activated a self-destruct mechanism in the rocket's nose cone after 20 seconds into flight. This report is a closeout document about the HyBoLT flight experiment. Details are provided of the objectives and approach associated with this experimental program as well as the 20 seconds flight data acquired before the vehicle was destroyed.

  17. The LT1 and LT2 variants of the enterotoxigenic Escherichia coli (ETEC) heat-labile toxin (LT) are associated with major ETEC lineages.

    PubMed

    Joffré, Enrique; Sjöling, Åsa

    2016-01-01

    The heat-labile toxin (LT) is one of the major virulence factors of enterotoxigenic Escherichia coli (ETEC). We recently described that 20 polymorphic LT variants are present in ETEC strains isolated globally. Two of the variants, LT1 and LT2, are particularly common and we found that they were associated with clonal ETEC lineages that express the colonization factors (CFs), CFA/I, CS1+CS3, CS2+CS3, and CS5+CS6. ETEC expressing these CFs are frequently found among ETEC strains isolated from cases with diarrhea. ETEC expressing the colonization factors CS1+CS3, and CS2+CS3 are found in 2 discrete clonal lineages and express the LT1 variant and heat stable toxin (STh). Although they clearly are virulent they neither produce, nor secrete, high amounts of LT toxin. On the other hand ETEC strains expressing LT, STh, CFA/I and LT, STh, CS5+CS6, carry the LT2 variant and produce and secrete significantly more LT toxin. Despite differences in toxin production, LT1 and LT2 are found in ETEC lineages that have managed to spread globally confirming that these variants are important for ETEC virulence. PMID:26939855

  18. The LT1 and LT2 variants of the enterotoxigenic Escherichia coli (ETEC) heat-labile toxin (LT) are associated with major ETEC lineages

    PubMed Central

    Joffré, Enrique; Sjöling, Åsa

    2016-01-01

    ABSTRACT The heat-labile toxin (LT) is one of the major virulence factors of enterotoxigenic Escherichia coli (ETEC). We recently described that 20 polymorphic LT variants are present in ETEC strains isolated globally. Two of the variants, LT1 and LT2, are particularly common and we found that they were associated with clonal ETEC lineages that express the colonization factors (CFs), CFA/I, CS1+CS3, CS2+CS3, and CS5+CS6. ETEC expressing these CFs are frequently found among ETEC strains isolated from cases with diarrhea. ETEC expressing the colonization factors CS1+CS3, and CS2+CS3 are found in 2 discrete clonal lineages and express the LT1 variant and heat stable toxin (STh). Although they clearly are virulent they neither produce, nor secrete, high amounts of LT toxin. On the other hand ETEC strains expressing LT, STh, CFA/I and LT, STh, CS5+CS6, carry the LT2 variant and produce and secrete significantly more LT toxin. Despite differences in toxin production, LT1 and LT2 are found in ETEC lineages that have managed to spread globally confirming that these variants are important for ETEC virulence. PMID:26939855

  19. ISMuLT Guidelines for muscle injuries

    PubMed Central

    Maffulli, Nicola; Oliva, Francesco; Frizziero, Antonio; Nanni, Gianni; Barazzuol, Michele; Via, Alessio Giai; Ramponi, Carlo; Brancaccio, Paola; Lisitano, Gianfranco; Rizzo, Diego; Freschi, Marco; Galletti, Stefano; Melegati, Gianluca; Pasta, Giulio; Testa, Vittorino; Valent, Alessandro; Del Buono, Angelo

    2013-01-01

    Summary Muscle injuries are frequent in high demand sports. No guidelines are available in the scientific literature. ISMuLT, the “Italian Society of Muscles, Ligaments and Tendons”, in line with its multidisciplinary mission, is proud to cover this gap. PMID:24596685

  20. Storm Enhanced Density (SED) plumes as possible suppliers of dayside cleft ion fountain

    NASA Astrophysics Data System (ADS)

    Horwitz, James

    Foster et al. [2002] have observed elevated ionospheric density regions being convected from the subauroral plasmaspheric region toward noon, in association with convection of plasmaspheric tails in the dayside magnetosphere. These so-called Storm Enhanced Density (SED) regions could serve as ionospheric plasma source populations for cleft ion fountain outflows. Here we examine this scenario and employ our fluid-kinetic ionospheric plasma transport code to simulate the entry of a high-density "plasmasphere-like" flux tube entering the cleft region and subjected to an episode of wave-driven transverse ion heating. We find that such pronounced intervals of SED at F-region and topside altitudes passing through regions of CIF processes indeed appear capable of supporting episodes of strong CIF outflows. Foster, J. C., P. J. Erickson, A. J. Coster, J. Goldstein, and F. J. Rich, Ionospheric signatures of plasmaspheric tails, Geophys. Res. Lett., 29(13), 1623, doi:10.1029/2002GL015067, 2002.

  1. Impaired physical function following pediatric LT.

    PubMed

    Feldman, Amy G; Neighbors, Katie; Mukherjee, Shubhra; Rak, Melanie; Varni, James W; Alonso, Estella M

    2016-04-01

    The purpose of this article is to investigate the spectrum of physical function of pediatric liver transplantation (LT) recipients 12-24 months after LT. Review data were collected through the functional outcomes group, an ancillary study of the Studies of Pediatric Liver Transplantation registry. Patients were eligible if they had survived LT by 12-24 months. Children ≥ 8 years and parents completed the Pediatric Quality of Life Inventory™ 4.0 generic core scales, which includes 8 questions assessing physical function. Scores were compared to a matched healthy child population (n = 1658) and between survivors with optimal versus nonoptimal health. A total of 263 patients were included. Median age at transplant and survey was 4.8 years (interquartile range [IQR], 1.3-11.4 years) and 5.9 years (IQR, 2.6-13.1 years), respectively. The mean physical functioning score on child and parent reports were 81.2 ± 17.3 and 77.1 ± 23.7, respectively. Compared to a matched healthy population, transplant survivors and their parents reported lower physical function scores (P < 0.001); 32.9% of patients and 35.0% of parents reported a physical function score <75, which is > 1 standard deviation below the mean of a healthy population. Physical functioning scores were significantly higher in survivors with optimal health than those with nonoptimal health (P < 0.01). There was a significant relationship between emotional functioning and physical functioning scores for LT recipients (r = 0.69; P < 0.001). In multivariate analysis, primary disease, height z score < -1.64 at longterm follow-up (LTF) visit,  > 4 days of hospitalization since LTF visit, and not being listed as status 1 were predictors of poor physical function. In conclusion, pediatric LT recipients 1-2 years after LT and their parents report lower physical function than a healthy population. Findings suggest practitioners need to routinely assess physical function, and

  2. Weak-intensity, basaltic, explosive volcanism: Dynamics of Hawaiian fountains

    NASA Astrophysics Data System (ADS)

    Parcheta, Carolyn

    Hawaiian fountains, typically occurring on basaltic volcanoes, are sustained, weakly-explosive jets of gas and juvenile ejecta. A broad range of Hawaiian fountaining styles occurred during twelve episodes of the Mauna Ulu eruption on Kilauea between May and December 1969. The western episode 1 fissure system is currently well exposed, providing an exclusive opportunity to study processes of low-intensity fissure fountains. Episode 1 fountains occurred along a 5 km long fissure system that exploited the eastern-most kilometer of the Ko'ai fault system. A low, near-continuous, spatter rampart is present on the northern upwind and upslope side of the fissure. Most pyroclastic products, however, fell downwind to the south and little was preserved because of two processes: 1) incorporation of proximal spatter in rheomorphic lava flows 10--20 meters from the vents, and 2) downslope transport of cooler spatter falling on top of these flows >20 meters from vent. There is a clear 'lava-shed' delineation between lava that drained back into the fissure and lava that continued flowing into the flowfield. Vents range in surface geometry from linear--circular, with superimposed irregularity and sinuosity, and range from straight-sided--flaring cross-sectional geometries. Irregularity results from joints in the pre-existing wall rock. Sinuosity results from the local stress field. Geometry of non-flared vents could indicate the true geometry of the dike. Flared vents likely formed through mechanical erosion and thermo-mechanical abrasion. Vent positions along the fissure likely resulted from flow focusing. Uniquely, these vents drained and remain unobstructed (some >100 m depth), despite subsequent nearby eruptive activity. Three vents were imaged .16 m in depth at <4 cm resolution with tripodmounted LiDAR. Textural analyses of pyroclasts from eruptive episodes 2.12 show three distinct degassing and outgassing paths: 1) rapid degassing and quenching with minimal outgassing, 2

  3. Factors influencing the height of Hawaiian lava fountains: implications for the use of fountain height as an indicator of magma gas content

    USGS Publications Warehouse

    Parfitt, E.A.; Wilson, L.; Neal, C.A.

    1995-01-01

    The heights of lava fountains formed in Hawaiian-style eruptions are controlled by magma gas content, volume flux and the amounts of lava re-entrainment and gas bubble coalescence. Theoretical models of lava fountaining are used to analyse data on lava fountain height variations collected during the 1983-1986 Pu'u 'O'o vent of Kilauea volcano, Hawaii. The results show that the variable fountain heights can be largely explained by the impact of variations in volume flux and amount of lava re-entrainment on erupting magmas with a constant gas content of ???0.32 wt.% H2O. However, the gas content of the magma apparently declined by ???0.05 wt.% during the last 10 episodes of the eruption series and this decline is attributed to more extensive pre-eruption degassing due to a shallowing of the sub-vent feeder dike. It is concluded that variations in lava fountain height cannot be simply interpreted as variations in gas content, as has previously been suggested, but that fountain height can still be a useful guide to minimum gas contents. Where sufficient data are available on eruptive volume fluxes and extent of lava entrainment, greatly improved estimates can be made of magma gas content from lava fountain height. ?? 1995 Springer-Verlag.

  4. Phase Separators And Fountain-Effect Pumps For He 11

    NASA Technical Reports Server (NTRS)

    Whitehouse, Paul L.

    1989-01-01

    Fused-glass microchannel arrays for use as HE 11 phase separators and fountain-effect pumps. Microchannel devices for use in low-gravity storage and cooling systems containing superfluid helium. Phase separators and pumps take advantage of thermomechanical effect peculiar to He 11 in restricted spaces. By creating thermal gradient in porous plug, direction of flow reversed, turning phase separator into pump. However, addition of heat disadvantage. Thermal gradient created by using Peltier effect to transfer heat across array, removing heat from He 11 supply and overcoming undesirable addition of heat.

  5. Granular fountains: Convection cascade in a compartmentalized granular gas

    NASA Astrophysics Data System (ADS)

    van der Meer, Devaraj; van der Weele, Ko; Reimann, Peter

    2006-06-01

    This paper extends the two-compartment granular fountain [D. van der Meer, P. Reimann, K. van der Weele, and D. Lohse, Phys. Rev. Lett. 92, 184301 (2004)] to an arbitrary number of compartments: The tendency of a granular gas to form clusters is exploited to generate spontaneous convective currents, with particles going down in the well-filled compartments and going up in the diluted ones. We focus upon the bifurcation diagram of the general K -compartment system, which is constructed using a dynamical flux model and which proves to agree quantitatively with results from molecular dynamics simulations.

  6. 78 FR 39628 - Endangered and Threatened Wildlife and Plants; Critical Habitat Map for the Fountain Darter

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-02

    ...We, the U.S. Fish and Wildlife Service (Service), are correcting the critical habitat map for the fountain darter (Etheostoma fonticola) in our regulations. We are taking this action to ensure regulated entities and the general public have an accurate critical habitat map for the species. This action does not change the designated critical habitat for the fountain...

  7. 21 CFR 1250.85 - Drinking fountains and coolers; ice; constant temperature bottles.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... temperature bottles. 1250.85 Section 1250.85 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... Drinking fountains and coolers; ice; constant temperature bottles. (a) Drinking fountains and coolers shall... temperature bottles. (c) Constant temperature bottles and other containers used for storing or...

  8. 21 CFR 1250.85 - Drinking fountains and coolers; ice; constant temperature bottles.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... temperature bottles. 1250.85 Section 1250.85 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... Drinking fountains and coolers; ice; constant temperature bottles. (a) Drinking fountains and coolers shall... temperature bottles. (c) Constant temperature bottles and other containers used for storing or...

  9. 21 CFR 1250.85 - Drinking fountains and coolers; ice; constant temperature bottles.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... temperature bottles. 1250.85 Section 1250.85 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... Drinking fountains and coolers; ice; constant temperature bottles. (a) Drinking fountains and coolers shall... temperature bottles. (c) Constant temperature bottles and other containers used for storing or...

  10. 21 CFR 1250.85 - Drinking fountains and coolers; ice; constant temperature bottles.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... temperature bottles. 1250.85 Section 1250.85 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... Drinking fountains and coolers; ice; constant temperature bottles. (a) Drinking fountains and coolers shall... temperature bottles. (c) Constant temperature bottles and other containers used for storing or...

  11. 21 CFR 1250.85 - Drinking fountains and coolers; ice; constant temperature bottles.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... temperature bottles. 1250.85 Section 1250.85 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... Drinking fountains and coolers; ice; constant temperature bottles. (a) Drinking fountains and coolers shall... temperature bottles. (c) Constant temperature bottles and other containers used for storing or...

  12. NIM5 Cs fountain clock and its evaluation

    NASA Astrophysics Data System (ADS)

    Fang, Fang; Li, Mingshou; Lin, Pingwei; Chen, Weiliang; Liu, Nianfeng; Lin, Yige; Wang, Ping; Liu, Kun; Suo, Rui; Li, Tianchu

    2015-08-01

    The cesium fountain primary frequency standard NIM5 has been developed at the National Institute of Metrology in China. The NIM5 loads atoms in an optical molasses from the background Cs vapor directly. Atoms are then cooled to a temperature of about 2 μK and launched to a height of 81 cm. The fringes of the Ramsey pattern have a width of 0.98 Hz. The NIM5 operates for more than 300 d a year, operating nearly continuously for 15 d at a time. By stabilizing the 9.19 GHz microwave frequency to the center of the central Ramsey fringe, a typical fractional frequency instability of 3 × 10-13 (τ/s)-1/2 is obtained when running at high atom density, and a combined uncertainty, including Type A and B uncertainties, is typically 1.6 × 10-15. Comparisons of data between NIM5 and 5 other fountain clocks were carried out in May 2013 via two-way satellite time and frequency transfer (TWSTFT), and the results show good agreement within the uncertainties. Six groups of NIM5 data from January to June 2014 have been published in Circular T 319 and 320.

  13. Recirculation of Laser Power in an Atomic Fountain

    NASA Technical Reports Server (NTRS)

    Enzer, Daphna G.; Klipstein, WIlliam M.; Moore, James D.

    2007-01-01

    A new technique for laser-cooling atoms in a cesium atomic fountain frequency standard relies on recirculation of laser light through the atom-collection region of the fountain. The recirculation, accomplished by means of reflections from multiple fixed beam-splitter cubes, is such that each of two laser beams makes three passes. As described below, this recirculation scheme offers several advantages over prior designs, including simplification of the laser system, greater optical power throughput, fewer optical and electrical connections, and simplification of beam power balancing. A typical laser-cooled cesium fountain requires the use of six laser beams arranged as three orthogonal pairs of counter-propagating beams to decelerate the atoms and hold them in a three-dimensional optical trap in vacuum. Typically, these trapping/cooling beams are linearly polarized and are positioned and oriented so that (1) counter-propagating beams in each pair have opposite linear polarizations and (2) three of the six orthogonal beams have the sum of their propagation directions pointing up, while the other three have the sum of their propagation directions pointing down. In a typical prior design, two lasers are used - one to generate the three "up" beams, the other to generate the three "down" beams. For this purpose, the output of each laser is split three ways, then the resulting six beams are delivered to the vacuum system, independently of each other, via optical fibers. The present recirculating design also requires two lasers, but the beams are not split before delivery. Instead, only one "up" beam and one oppositely polarized "down" beam are delivered to the vacuum system, and each of these beams is sent through the collection region three times. The polarization of each beam on each pass through the collection region is set up to yield the same combination of polarization and propagation directions as described above. In comparison with the prior design, the present

  14. Low-Light-Shift Cesium Fountain without Mechanical Shutters

    NASA Technical Reports Server (NTRS)

    Enzer, Daphna

    2008-01-01

    A new technique for reducing errors in a laser-cooled cesium fountain frequency standard provides for strong suppression of the light shift without need for mechanical shutters. Because mechanical shutters are typically susceptible to failure after operating times of the order of months, the elimination of mechanical shutters could contribute significantly to the reliability of frequency standards that are required to function continuously for longer time intervals. With respect to the operation of an atomic-fountain frequency standard, the term "light shift" denotes an undesired relative shift in the two energy levels of the atoms (in this case, cesium atoms) in the atomic fountain during interrogation by microwaves. The shift in energy levels translates to a frequency shift that reduces the precision and possibly accuracy of the frequency standard. For reasons too complex to describe within the space available for this article, the light shift is caused by any laser light that reaches the atoms during the microwave- interrogation period, but is strongest for near-resonance light. In the absence of any mitigating design feature, the light shift, expressed as a fraction of the standard fs frequency, could be as large as approx. 2 x 10(exp -11), the largest error in the standard. In a typical prior design, to suppress light shift, the intensity of laser light is reduced during the interrogation period by using a single-pass acoustooptic modulator to deflect the majority of light away from the main optical path. Mechanical shutters are used to block the remaining undeflected light to ensure complete attenuation. Without shutters, this remaining undeflected light could cause a light shift of as much as .10.15, which is unacceptably large in some applications. The new technique implemented here involves additionally shifting the laser wavelength off resonance by a relatively large amount (typically of the order of nanometers) during microwave interrogation. In this

  15. Large-eddy simulations of excitation effects on a VTOL upwash fountain

    NASA Astrophysics Data System (ADS)

    Rizk, Magdi H.; Menon, Suresh

    1989-04-01

    The responses of an upwash fountain to various azimuthal and axisymmetric excitations, applied at the exits of its neighboring jets, are investigated. Kinematic arguments are used to determine the interactions of large-scale structures in the fountain and the effects of these interactions on the fountain's characteristics. Numerical simulations of a row of impinging jets, which contain the essential features of twin jets impinging on the ground, are used to simulate the hovering configuration of a vertical takeoff and landing (VTOL) aircraft. The flow is assumed to be governed by the time-dependent, incompressible Navier-Stokes equations. The large-eddy simulation approach is followed. Distinct fountain characteristics are shared among the cases in which azimuthal perturbations are applied at both jet exits in the same direction. These include a high fountain spreading rate, a strong lateral interaction with the neighboring jets, and a weak upload at the aircraft's undersurface. A strong similarity in fountain characteristics also exists for the cases of axisymmetric forcing and azimuthal forcing in opposite directions at the two jet exits. The similar characteristics here include a low fountain spreading rate and a strong upload at the aircraft's undersurface.

  16. Nosocomial outbreak of Pseudomonas aeruginosa associated with a drinking water fountain.

    PubMed

    Costa, D; Bousseau, A; Thevenot, S; Dufour, X; Laland, C; Burucoa, C; Castel, O

    2015-11-01

    Over a four-month period, ten patients were suspected of having acquired nosocomial infection to P. aeruginosa in the ear, nose, and throat department. Environmental and clinical isolates were compared. Only water from a drinking water fountain was contaminated by P. aeruginosa. This isolate and those of three patients had indistinguishable random amplified polymorphic DNA profiles. These patients had serious oncology diseases. The drinking water fountain was used for their alimentation by percutaneous endoscopic gastrostomy and was the origin of the outbreak. Another type of drinking fountain with a terminal ultraviolet treatment was installed, following which no new infections linked to drinking water were identified. PMID:26341271

  17. Recent improvements on the atomic fountain clock at SIOM

    NASA Astrophysics Data System (ADS)

    Du, Yuan-Bo; Wei, Rong; Dong, Ri-Chang; Zou, Fan; Wang, Yu-Zhu

    2015-07-01

    We report the recent advance in our rubidium atomic fountain clock (AFC). The parameters of the Ramsey cavity are optimized by balancing the coupling from the two ports. The temperature control system of the Ramsey interaction region is renovated, and the resonant temperature of the Ramsey cavity is regulated to be slightly above the room temperature. The quality of magnetic environment in the Ramsey interaction region is also improved. A new digital-to-analog converter (DAC) circuit that controls the local oscillator is adopted to decrease the noise of the oven-controlled crystal oscillator output. As a result, the short-term fractional frequency stability of 2.7 × 10-13τ-1/2 and the long-term fractional frequency stability of 1.6 × 10-15 at the average time of 32800 s are achieved. Project supported by the National Natural Science Foundation of China (Grant Nos. 61275204 and 91336105).

  18. Operating characteristics of isocaloric fountain-effect pumps

    NASA Technical Reports Server (NTRS)

    Kittel, Peter

    1988-01-01

    The governing equations of thermomechanical (fountain-effect) pumps are usually given for pumps operating at a constant temperature difference. These are the thermomechanical and mechanocaloric effects in which the pressure head and mass flow are independent of each other. Here, these equations are recast for a pump operating at a constant heat input (isocaloric). This form more closely represents how such pumps are likely to be used. Under these conditions, the pressure head and mass flow are shown to be related. For ideal pumps, the head and flow are related by a universal curve. For real pumps (those that have normal fluid leakage), a family of curves is developed. These curves approach the curve for an ideal pump at high flow rates. The isocaloric equations are also extended to multistage pumps.

  19. On the transition from strombolian to fountaining activity: a thermal energy-based driver

    NASA Astrophysics Data System (ADS)

    Bombrun, Maxime; Spampinato, Letizia; Harris, Andrew; Barra, Vincent; Caltabiano, Tommaso

    2016-02-01

    Since 1999, Mount Etna's (Italy) South-East crater system has been characterised by episodic lava fountaining. Each episode is characterised by initial strombolian activity followed by transition to sustained fountaining to feed high-effusion rate lava flow. Here, we use thermal infrared data recorded by a permanent radiometer station to characterise the transition to sustained fountaining fed by the New South-East crater that developed on the eastern flank of the South-East crater starting from January 2011. We cover eight fountaining episodes that occurred between 2012 and 2013. We first developed a routine to characterise event waveforms apparent in the precursory, strombolian phase. This allowed extraction of a database for thermal energy and waveform shape for 1934 events. We detected between 66 and 650 events per episode, with event durations being between 4 and 55 s. In total, 1508 (78 %) of the events had short waxing phases and dominant waning phases. Event frequency increased as climax was approached. Events had energies of between 3.0 × 106 and 5.8 × 109 J, with rank order analysis indicating the highest possible event energy of 8.1 × 109 J. To visualise the temporal evolution of retrieved parameters during the precursory phase, we applied a dimensionality reduction technique. Results show that weaker events occur during an onset period that forms a low-energy "sink". The transition towards fountaining occurs at 107 J, where subsequent events have a temporal trend towards the highest energies, and where sustained fountaining occurs when energies exceed 109 J. Such an energy-based framework allows researchers to track the evolution of fountaining episodes and to predict the time at which sustained fountaining will begin.

  20. Regular and chaotic dynamics of a fountain in a stratified fluid

    NASA Astrophysics Data System (ADS)

    Druzhinin, O. A.; Troitskaya, Yu. I.

    2012-06-01

    In the present paper, we study by direct numerical simulation (DNS) and theoretical analysis, the dynamics of a fountain penetrating a pycnocline (a sharp density interface) in a density-stratified fluid. A circular, laminar jet flow of neutral buoyancy is considered, which propagates vertically upwards towards the pycnocline level, penetrates a distance into the layer of lighter fluid, and further stagnates and flows down under gravity around the up-flowing core thus creating a fountain. The DNS results show that if the Froude number (Fr) is small enough, the fountain top remains axisymmetric and steady. However, if Fr is increased, the fountain top becomes unsteady and oscillates in a circular flapping (CF) mode, whereby it retains its shape and moves periodically around the jet central axis. If Fr is increased further, the fountain top rises and collapses chaotically in a bobbing oscillation mode (or B-mode). The development of these two modes is accompanied by the generation of different patterns of internal waves (IW) in the pycnocline. The CF-mode generates spiral internal waves, whereas the B-mode generates IW packets with a complex spatial distribution. The dependence of the amplitude of the fountain-top oscillations on Fr is well described by a Landau-type two-mode-competition model.

  1. Regular and chaotic dynamics of a fountain in a stratified fluid.

    PubMed

    Druzhinin, O A; Troitskaya, Yu I

    2012-06-01

    In the present paper, we study by direct numerical simulation (DNS) and theoretical analysis, the dynamics of a fountain penetrating a pycnocline (a sharp density interface) in a density-stratified fluid. A circular, laminar jet flow of neutral buoyancy is considered, which propagates vertically upwards towards the pycnocline level, penetrates a distance into the layer of lighter fluid, and further stagnates and flows down under gravity around the up-flowing core thus creating a fountain. The DNS results show that if the Froude number (Fr) is small enough, the fountain top remains axisymmetric and steady. However, if Fr is increased, the fountain top becomes unsteady and oscillates in a circular flapping (CF) mode, whereby it retains its shape and moves periodically around the jet central axis. If Fr is increased further, the fountain top rises and collapses chaotically in a bobbing oscillation mode (or B-mode). The development of these two modes is accompanied by the generation of different patterns of internal waves (IW) in the pycnocline. The CF-mode generates spiral internal waves, whereas the B-mode generates IW packets with a complex spatial distribution. The dependence of the amplitude of the fountain-top oscillations on Fr is well described by a Landau-type two-mode-competition model. PMID:22757523

  2. Scanning Electron Microscopy and Petrography of Glassy Particles Produced by Lava Fountain Eruptions. Ph.D. Thesis - Final Report

    NASA Technical Reports Server (NTRS)

    Ladle, G. H.

    1978-01-01

    A conceptual model of a lava fountain consists of a vent, spatter ramparts, fountain column, downwind plume and associated pumice deposits. Glassy particles produced by lava fountain eruptions consist primarily of sideromelane glass and minor to moderate amounts of vesicles and crystals. Particles are classified on the basis of morphology as: (1) spherical, (2) elongate, (3) glass-coated mineral grain, (4) shard, (5) reticulite, (6) composite particle, and (7) lithic fragment.

  3. Star Trek's Lt. Uhura's Warp-Speed Visit to Dryden

    NASA Video Gallery

    Actress Nichelle Nichols warped to many worlds as Lt. Uhura in the 1960s Star Trek TV show. However, her real-life adventures have taken her to where no one has gone before in advocacy for NASA and...

  4. Open-path FTIR spectroscopy of magma degassing processes during eight lava fountains on Mount Etna

    NASA Astrophysics Data System (ADS)

    La Spina, Alessandro; Burton, Mike; Allard, Patrick; Alparone, Salvatore; Murè, Filippo

    2016-04-01

    In June-July 2001 a series of 16 discrete lava fountain paroxysms occurred at the Southeast summit crater (SEC) of Mount Etna, preceding a 28-day long violent flank eruption. Each paroxysm was preceded by lava effusion, growing seismic tremor and a crescendo of Strombolian explosive activity culminating into powerful lava fountaining up to 500m in height. During 8 of these 16 events we could measure the chemical composition of the magmatic gas phase (H2O, CO2, SO2, HCl, HF and CO), using open-path Fourier transform infrared (OP-FTIR) spectrometry at ˜1-2km distance from SEC and absorption spectra of the radiation emitted by hot lava fragments. We show that each fountaining episode was characterized by increasingly CO2-rich gas release, with CO2/SO2and CO2/HCl ratios peaking in coincidence with maxima in seismic tremor and fountain height, whilst the SO2/HCl ratio showed a weak inverse relationship with respect to eruption intensity. Moreover, peak values in both CO2/SO2ratio and seismic tremor amplitude for each paroxysm were found to increase linearly in proportion with the repose interval (2-6 days) between lava fountains. These observations, together with a model of volatile degassing at Etna, support the following driving process. Prior to and during the June-July 2001 lava fountain sequence, the shallow (˜2km) magma reservoir feeding SEC received an increasing influx of deeply derived carbon dioxide, likely promoted by the deep ascent of volatile-rich primitive basalt that produced the subsequent flank eruption. This CO2-rich gas supply led to gas accumulation and overpressure in SEC reservoir, generating a bubble foam layer whose periodical collapse powered the successive fountaining events. The anti-correlation between SO2/HCl and eruption intensity is best explained by enhanced syn-eruptive degassing of chlorine from finer particles produced during more intense magma fragmentation.

  5. Open-path FTIR spectroscopy of magma degassing processes during eight lava fountains on Mount Etna

    NASA Astrophysics Data System (ADS)

    La Spina, Alessandro; Burton, Mike; Allard, Patrick; Alparone, Salvatore; Muré, Filippo

    2015-03-01

    In June-July 2001 a series of 16 discrete lava fountain paroxysms occurred at the Southeast summit crater (SEC) of Mount Etna, preceding a 28-day long violent flank eruption. Each paroxysm was preceded by lava effusion, growing seismic tremor and a crescendo of Strombolian explosive activity culminating into powerful lava fountaining up to 500 m in height. During 8 of these 16 events we could measure the chemical composition of the magmatic gas phase (H2O, CO2, SO2, HCl, HF and CO), using open-path Fourier transform infrared (OP-FTIR) spectrometry at ∼1-2 km distance from SEC and absorption spectra of the radiation emitted by hot lava fragments. We show that each fountaining episode was characterized by increasingly CO2-rich gas release, with CO2/SO2 and CO2/HCl ratios peaking in coincidence with maxima in seismic tremor and fountain height, whilst the SO2/HCl ratio showed a weak inverse relationship with respect to eruption intensity. Moreover, peak values in both CO2/SO2 ratio and seismic tremor amplitude for each paroxysm were found to increase linearly in proportion with the repose interval (2-6 days) between lava fountains. These observations, together with a model of volatile degassing at Etna, support the following driving process. Prior to and during the June-July 2001 lava fountain sequence, the shallow (∼2 km) magma reservoir feeding SEC received an increasing influx of deeply derived carbon dioxide, likely promoted by the deep ascent of volatile-rich primitive basalt that produced the subsequent flank eruption. This CO2-rich gas supply led to gas accumulation and overpressure in SEC reservoir, generating a bubble foam layer whose periodical collapse powered the successive fountaining events. The anti-correlation between SO2/HCl and eruption intensity is best explained by enhanced syn-eruptive degassing of chlorine from finer particles produced during more intense magma fragmentation.

  6. Copper dimer interactions on a thermomechanical superfluid {sup 4}He fountain

    SciTech Connect

    Popov, Evgeny; Eloranta, Jussi

    2015-05-28

    Laser induced fluorescence imaging and frequency domain excitation spectroscopy of the copper dimer (B{sup 1}Σ{sub g}{sup +}←X{sup 1}Σ{sub u}{sup +}) in thermomechanical helium fountain at 1.7 K are demonstrated. The dimers penetrate into the fountain provided that their average propagation velocity is ca. 15 m/s. This energy threshold is interpreted in terms of an imperfect fountain liquid-gas interface, which acts as a trap for low velocity dimers. Orsay-Trento density functional theory calculations for superfluid {sup 4}He are used to characterize the dynamics of the dimer solvation process into the fountain. The dimers first accelerate towards the fountain surface and once the surface layer is crossed, they penetrate into the liquid and further slow down to Landau critical velocity by creating a vortex ring. Theoretical lineshape calculations support the assignment of the experimentally observed bands to Cu{sub 2} solvated in the bulk liquid. The vibronic progressions are decomposed of a zero-phonon line and two types of phonon bands, which correlate with solvent cavity interface compression (t < 200 fs) and expansion (200 < t < 500 fs) driven by the electronic excitation. The presented experimental method allows to perform molecular spectroscopy in bulk superfluid helium where the temperature and pressure can be varied.

  7. Balancing bulk gas accumulation and gas output before and during lava fountaining episodes at Mt. Etna

    NASA Astrophysics Data System (ADS)

    Carbone, Daniele; Zuccarello, Luciano; Messina, Alfio; Scollo, Simona; Rymer, Hazel

    2015-12-01

    We focus on a sequence of 9 lava fountains from Etna that occurred in 2011, separated by intervals of 5 to 10 days. Continuous measurements allowed to discover the occurrence of gravity decreases before the onset of most fountaining episodes. We propose that the gravity changes are due to the pre-fountaining accumulation of a foam layer at shallow levels in the plumbing system of the volcano. Relying on the relationship between amount of gas trapped in the foam and amount of gas emitted during each episode, we develop a conceptual model of the mechanism controlling the passage from Strombolian to lava fountaining activity. Gas leakage from the foam layer during the late stages of its accumulation increases the gas volume fraction at upper levels, thus inducing a decrease of the magma-static pressure in the trapping zone and a further growth of the foam. This feedback mechanism eventually leads to the collapse of the foam layer and to the onset of lava fountaining. The possibility to detect the development of a foam layer at depth and to set quantitative constraints on the amount of trapped gas is important because of the implications for forecasting explosive eruptions and predicting their intensity.

  8. Balancing bulk gas accumulation and gas output before and during lava fountaining episodes at Mt. Etna.

    PubMed

    Carbone, Daniele; Zuccarello, Luciano; Messina, Alfio; Scollo, Simona; Rymer, Hazel

    2015-01-01

    We focus on a sequence of 9 lava fountains from Etna that occurred in 2011, separated by intervals of 5 to 10 days. Continuous measurements allowed to discover the occurrence of gravity decreases before the onset of most fountaining episodes. We propose that the gravity changes are due to the pre-fountaining accumulation of a foam layer at shallow levels in the plumbing system of the volcano. Relying on the relationship between amount of gas trapped in the foam and amount of gas emitted during each episode, we develop a conceptual model of the mechanism controlling the passage from Strombolian to lava fountaining activity. Gas leakage from the foam layer during the late stages of its accumulation increases the gas volume fraction at upper levels, thus inducing a decrease of the magma-static pressure in the trapping zone and a further growth of the foam. This feedback mechanism eventually leads to the collapse of the foam layer and to the onset of lava fountaining. The possibility to detect the development of a foam layer at depth and to set quantitative constraints on the amount of trapped gas is important because of the implications for forecasting explosive eruptions and predicting their intensity. PMID:26656099

  9. Balancing bulk gas accumulation and gas output before and during lava fountaining episodes at Mt. Etna

    PubMed Central

    Carbone, Daniele; Zuccarello, Luciano; Messina, Alfio; Scollo, Simona; Rymer, Hazel

    2015-01-01

    We focus on a sequence of 9 lava fountains from Etna that occurred in 2011, separated by intervals of 5 to 10 days. Continuous measurements allowed to discover the occurrence of gravity decreases before the onset of most fountaining episodes. We propose that the gravity changes are due to the pre-fountaining accumulation of a foam layer at shallow levels in the plumbing system of the volcano. Relying on the relationship between amount of gas trapped in the foam and amount of gas emitted during each episode, we develop a conceptual model of the mechanism controlling the passage from Strombolian to lava fountaining activity. Gas leakage from the foam layer during the late stages of its accumulation increases the gas volume fraction at upper levels, thus inducing a decrease of the magma-static pressure in the trapping zone and a further growth of the foam. This feedback mechanism eventually leads to the collapse of the foam layer and to the onset of lava fountaining. The possibility to detect the development of a foam layer at depth and to set quantitative constraints on the amount of trapped gas is important because of the implications for forecasting explosive eruptions and predicting their intensity. PMID:26656099

  10. THE FIRST ''WATER FOUNTAIN'' COLLIMATED OUTFLOW IN A PLANETARY NEBULA

    SciTech Connect

    Gómez, José F.; Miranda, Luis F.; Guerrero, Martín A.; Rizzo, J. Ricardo; García-García, Enrique; Green, James A.; Uscanga, Lucero; Ramos-Larios, Gerardo

    2015-02-01

    ''Water fountains'' (WFs) are evolved objects showing high-velocity, collimated jets traced by water maser emission. Most of them are in the post-asymptotic giant branch (post-AGB) and they may represent one of the first manifestations of collimated mass loss in evolved stars. We present water maser, carbon monoxide, and mid-infrared spectroscopic data (obtained with the Australia Telescope Compact Array, Herschel Space Observatory, and the Very Large Telescope, respectively) toward IRAS 15103–5754, a possible planetary nebula (PN) with WF characteristics. Carbon monoxide observations show that IRAS 15103–5754 is an evolved object, while the mid-IR spectrum displays unambiguous [Ne II] emission, indicating that photoionization has started and thus, its nature as a PN is confirmed. Water maser spectra show several components spreading over a large velocity range (≅ 75 km s{sup –1}) and tracing a collimated jet. This indicates that the object is a WF, the first WF known that has already entered the PN phase. However, the spatial and kinematical distribution of the maser emission in this object are significantly different from those in other WFs. Moreover, the velocity distribution of the maser emission shows a ''Hubble-like'' flow (higher velocities at larger distances from the central star), consistent with a short-lived, explosive mass-loss event. This velocity pattern is not seen in other WFs (which are presumably in earlier evolutionary stages). We therefore suggest that we are witnessing a fundamental change of mass-loss processes in WFs, with water masers being pumped by steady jets in post-AGB stars, but tracing explosive/ballistic events as the object enters the PN phase.

  11. The First "Water Fountain" Collimated Outflow in a Planetary Nebula

    NASA Astrophysics Data System (ADS)

    Gómez, José F.; Suárez, Olga; Bendjoya, Philippe; Rizzo, J. Ricardo; Miranda, Luis F.; Green, James A.; Uscanga, Lucero; García-García, Enrique; Lagadec, Eric; Guerrero, Martín A.; Ramos-Larios, Gerardo

    2015-02-01

    "Water fountains" (WFs) are evolved objects showing high-velocity, collimated jets traced by water maser emission. Most of them are in the post-asymptotic giant branch (post-AGB) and they may represent one of the first manifestations of collimated mass loss in evolved stars. We present water maser, carbon monoxide, and mid-infrared spectroscopic data (obtained with the Australia Telescope Compact Array, Herschel Space Observatory, and the Very Large Telescope, respectively) toward IRAS 15103-5754, a possible planetary nebula (PN) with WF characteristics. Carbon monoxide observations show that IRAS 15103-5754 is an evolved object, while the mid-IR spectrum displays unambiguous [Ne II] emission, indicating that photoionization has started and thus, its nature as a PN is confirmed. Water maser spectra show several components spreading over a large velocity range (sime 75 km s-1) and tracing a collimated jet. This indicates that the object is a WF, the first WF known that has already entered the PN phase. However, the spatial and kinematical distribution of the maser emission in this object are significantly different from those in other WFs. Moreover, the velocity distribution of the maser emission shows a "Hubble-like" flow (higher velocities at larger distances from the central star), consistent with a short-lived, explosive mass-loss event. This velocity pattern is not seen in other WFs (which are presumably in earlier evolutionary stages). We therefore suggest that we are witnessing a fundamental change of mass-loss processes in WFs, with water masers being pumped by steady jets in post-AGB stars, but tracing explosive/ballistic events as the object enters the PN phase.

  12. Discrete blasts in granular material yield two-stage process of cavitation and granular fountaining

    NASA Astrophysics Data System (ADS)

    Andrews, Robin; White, James; Dürig, Tobi; Zimanowski, Bernd

    2014-05-01

    A discrete blast within granular material, such as a single subterranean explosion within a debris-filled diatreme structure, is typically considered to produce a single uprush of material. Our experiments demonstrate that apparent "debris jet deposits" can be formed by a two-stage process of cavitation and subsequent granular fountaining. Bench-scale experiments reported here demonstrate that for a range of overpressures and depths, individual, discrete, buried gas blasts open space and expel particles from the blast site in two largely decoupled stages. Expanding gas initially pierces material nearest the blast source to open a cavity above it; then a fountain of grains rises from the source into the cavity. This staged motion dynamically segregates source grains from host-material grains, and the rates of cavity opening vs. fountain rise show a power-law decay relationship with initial pressure. Our experimental analysis has implications for maar-diatreme systems, field-scale detonation experiments, and underground nuclear testing.

  13. Discrete blasts in granular material yield two-stage process of cavitation and granular fountaining

    NASA Astrophysics Data System (ADS)

    Andrews, Robin G.; White, James D. L.; Dürig, Tobi; Zimanowski, Bernd

    2014-01-01

    A discrete blast within granular material, such as a single subterranean explosion within a debris-filled diatreme structure, is typically considered to produce a single uprush of material. Our experiments demonstrate that apparent "debris jet deposits" can be formed by a two-stage process of cavitation and subsequent granular fountaining. Bench-scale experiments reported here demonstrate that for a range of overpressures and depths, individual, discrete, buried gas blasts open space and expel particles from the blast site in two largely decoupled stages. Expanding gas initially pierces material nearest the blast source to open a cavity above it; then a fountain of grains rises from the source into the cavity. This staged motion dynamically segregates source grains from host-material grains, and the rates of cavity opening versus fountain rise show a power law decay relationship with initial pressure. Our experimental analysis has implications for maar-diatreme systems, field-scale detonation experiments, and underground nuclear testing.

  14. Loading a fountain clock with an enhanced low-velocity intense source of atoms

    NASA Astrophysics Data System (ADS)

    Dobrev, G.; Gerginov, V.; Weyers, S.

    2016-04-01

    We present experimental work for improved atom loading in the optical molasses of a cesium fountain clock, employing a low-velocity intense source of atoms [Lu et al., Phys. Rev. Lett 77, 3331 (1996), 10.1103/PhysRevLett.77.3331], which we modify by adding a dark-state pump laser. With this modification the atom source has a mean flux of 4 ×108 atoms/s at a mean atom velocity of 8.6 m/s. Compared to fountain operation using background gas loading, we achieve a significant increase of the loaded and detected atom number by a factor of 40. Operating the fountain clock with a total number of detected atoms Nat=2.9 ×106 in the quantum projection noise-limited regime, a frequency instability σy(1 s ) =2.7 ×10-14 is demonstrated.

  15. Ground water in Fountain and Jimmy Camp Valleys, El Paso County, Colorado with a section on Computations of drawdowns caused by the pumping of wells in Fountain Valley

    USGS Publications Warehouse

    Jenkins, Edward D.; Glover, Robert E.

    1964-01-01

    The part of Fountain Valley considered in this report extends from Colorado Springs to the Pueblo County line. It is 23 miles long and has an area of 26 square miles. The part of Jimmy Camp Valley discussed is 11 miles long and has an area of 9 square miles. The topography is characterized by level flood plains and alluvial terraces that parallel the valley and by rather steep hills along the valley sides. The climate is semiarid, average annual precipitation being about 13 inches. Farming and stock raising are the principal occupations in the valleys; however, some of the agricultural land near Colorado Springs is being used for housing developments. The Pierre Shale and alluvium underlie most of the area, and mesa gravel caps the shale hills adjacent to Fountain Valley. The alluvium yields water to domestic, stock, irrigation, and public-supply wells and is capable of yielding large quantities of water for intermittent periods. Several springs issue along the sides of the valley at the contact of the mesa gravel and the underlying Pierre Shale. The water table ranges in depth from less than 10 feet along the bottom lands to about 80 feet along the sides of the valleys; the saturated thickness ranges from less than a foot to about 50 feet. The ground-water reservoir in Fountain Valley is recharged by precipitation that falls within the area, by percolation from Fountain Creek, which originates in the Pikes Peak, Monument Valley, and Rampart Range areas, and by seepage from irrigation water. This reservoir contains about 70,000 acre-feet of ground water in storage. The ground-water reservoir in Jimmy Camp Valley is recharged from precipitation that falls within the area, by percolation from Jimmy Camp Creek during periods of streamflow, and by seepage from irrigation water. The Jimmy Camp ground-water reservoir contains about 25,000 acre-feet of water in storage. Ground water is discharged from the area by movement to the south, by evaporation and transpiration in

  16. Perceptions of Tap Water and School Water Fountains and Association with Intake of Plain Water and Sugar-Sweetened Beverages

    ERIC Educational Resources Information Center

    Onufrak, Stephen J.; Park, Sohyun; Sharkey, Joseph R.; Merlo, Caitlin; Dean, Wesley R.; Sherry, Bettylou

    2014-01-01

    Background: Little is known regarding youth perceptions of tap water and school water fountains and how these relate to water and sugar-sweetened beverage (SSB) intake. Methods: We used national 2010 YouthStyles data to assess perceptions of tap water and school water fountains and associations with water and SSB intake. Results: Nearly 1 in 5…

  17. Contrasting patterns of vesiculation in low, intermediate, and high Hawaiian fountains: A case study of the 1969 Mauna Ulu eruption

    NASA Astrophysics Data System (ADS)

    Parcheta, C. E.; Houghton, B. F.; Swanson, D. A.

    2013-04-01

    Hawaiian-style eruptions, or Hawaiian fountains, typically occur at basaltic volcanoes and are sustained, weakly explosive jets of gas and dominantly coarse, juvenile ejecta (dense spatter to delicate reticulite). Almost the entire range of styles and mass eruption rates within Hawaiian fountaining occurred during twelve fountaining episodes recorded at Mauna Ulu, Kīlauea between May and December 1969. Such diversity in intensity and style is controlled during magma ascent by many processes that can be constrained by the size and shape of vesicles in the 1969 pyroclasts. This paper describes pyroclast vesicularity from high, intermediate, and low fountaining episodes with eruption rates from 0.05 to 1.3 × 106 m3 h- 1. As each eruptive episode progressed, magma ascent slowed in and around the vent system, offering extended time for bubbles to grow and coalesce. Late ejected pyroclasts are thus characterized by populations of fewer and larger vesicles with relaxed shapes. This progression continued in the intervals between episodes after termination of fountain activity. The time scale for this process of shallow growth, coalescence and relaxation of bubbles is typically tens of hours. Rims and cores of pumiceous pyroclasts from moderate to high fountaining episodes record a second post-fragmentation form of vesicle maturation. Partially thermally insulated pyroclasts can have internal bubble populations evolve more dynamically with continued growth and coalescence, on a time scale of only minutes, during transport in the fountains. Reticulite, which formed in a short-lived fountain 540 m in height, underwent late, short-lived bubble nucleation followed by rapid growth of a uniform bubble population in a thermally insulated fountain, and quenched at the onset of permeability before significant coalescence. These contrasting patterns of shallow degassing and outgassing were the dominant controls in determining both the form and duration of fountaining episodes at

  18. SODA FOUNTAIN-LUNCHEONETTE EQUIPMENT AND APPURTENANCES. NATIONAL SANITATION FOUNDATION STANDARD NO. 1.

    ERIC Educational Resources Information Center

    National Sanitation Foundation, Ann Arbor, MI.

    THIS STANDARD OF SODA FOUNTAIN-LUNCHEONETTE EQUIPMENT IS THE FIRST IN A SERIES OF NATIONAL SANITATION FOUNDATION STANDARDS. THESE STANDARDS ARE ISSUED IN RECOGNITION OF THE LONG FELT NEED FOR A COMMON UNDERSTANDING OF THE PROBLEMS OF SANITATION INVOLVING INDUSTRIAL AND ADMINISTRATIVE HEALTH OFFICIALS WHOSE OBLIGATION IT IS TO ENFORCE REGULATIONS.…

  19. Status and prospect of the Swiss continuous Cs fountain FoCS-2

    NASA Astrophysics Data System (ADS)

    Jallageas, A.; Devenoges, L.; Petersen, M.; Morel, J.; Bernier, L.-G.; Thomann, P.; Südmeyer, T.

    2016-06-01

    The continuous cesium fountain clock FoCS-2 at METAS presents many unique characteristics and challenges in comparison with standard pulsed fountain clocks. For several years FoCS-2 was limited by an unexplained frequency sensitivity on the velocity of the atoms, in the range of 140 • 10-15. Recent experiments allowed us to identify the origin of this problem as undesirable microwave surface currents circulating on the shield of the coaxial cables that feed the microwave cavity. A strong reduction of this effect was obtained by adding microwave absorbing coatings on the coaxial cables and absorbers inside of the vacuum chamber. This breakthrough opens the door to a true metrological validation of the fountain. A series of simulation tools have already been developed and proved their efficiency in the evaluation of some of the uncertainties of the continuous fountain. With these recent improvements, we are confident in the future demonstration of an uncertainty budget at the 10-15 level and below.

  20. Lava Fountaining Discharge Regime driven by Slug-to-Churn Flow Transition. (Invited)

    NASA Astrophysics Data System (ADS)

    Ripepe, M.; Pioli, L.; Marchetti, E.; Ulivieri, G.

    2013-12-01

    Lava fountaining episodes at Etna volcano appear characterized by the transition between Strombolian and Hawaiian end-member eruptive styles. There is no evidence for this transition in the seismic (i.e. seismic tremor) signal. However, infrasonic records provide unprecedented evidence on this flow transition. Each eruptive episode is characterized by distinctive common trend in the amplitude, waveform and frequency content of the infrasonic wavefield, which evidences the shift from discrete, and transient, strombolian to sustained, and oscillatory, lava fountain dynamics. Large scale experiments on the dynamics of two-phase flow of basaltic magmas show how the transition between different regimes mainly depends on gas volume flow, which in turn controls pressure distribution within the conduit and also magma vesicularity. In particular, while regular large bubble bursting is associated with slug flow regime, large amplitude and low frequency column oscillations are associated with churn flow. In large pipes, transition from slug to churn flow regime is independent on conduit diameter and it is reached at high superficial gas velocity. Lava fountaining episodes at Etna can be thus interpreted as induced by the transition from the slug (discrete strombolian) to churn flow (sustained lava fountain) regimes that is reflecting an increase in the gas discharge rate. Based on laboratory experiments, we calculate that transition between these two end-member explosive regimes at Etna occurs when gas superficial velocity is 76 m/s for near-the-vent stagnant magma conditions.

  1. Operation Facelift: Cover Makeovers Can Be the Fountain of Youth for Many Titles

    ERIC Educational Resources Information Center

    Jones, Leigh Ann

    2009-01-01

    Aging covers and those that miss their mark and lead to sluggish sales are often targeted for makeovers, many times with good results. Up to 75 percent of Viking's books get redesigned, says Assistant Art Director Jim Hoover, because the publisher sees it as a chance to reintroduce a book to the market. Makeovers are considered the fountain of…

  2. Simplified thermodynamic functions for vapor-liquid phase separation and fountain effect pumps

    NASA Technical Reports Server (NTRS)

    Yuan, S. W. K.; Hepler, W. A.; Frederking, T. H. K.

    1984-01-01

    He-4 fluid handling devices near 2 K require novel components for non-Newtonian fluid transport in He II. Related sizing of devices has to be based on appropriate thermophysical property functions. The present paper presents simplified equilibrium state functions for porous media components which serve as vapor-liquid phase separators and fountain effect pumps.

  3. 16. WEST ELEVATION. MONOMOY POINT LT. STATION, MASS., SHOWING PROPOSED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. WEST ELEVATION. MONOMOY POINT LT. STATION, MASS., SHOWING PROPOSED ALTERATION AND IMPROVEMENT OF DWELLING. No. 1343. SHEET 3 of 5. July 1899. - Monomoy Point Light Station, Approximately 3500 feet Northeast Powder Hole Pond, Monomoy National Wildlife Refuge, Chatham, Barnstable County, MA

  4. 18. EXISTING FIRST FLOOR PLAN. MONOMOY POINT LT. STATION, MASS., ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. EXISTING FIRST FLOOR PLAN. MONOMOY POINT LT. STATION, MASS., SHOWING PROPOSED ALTERATION AND IMPROVEMENT OF DWELLING. No. 1343. Sheet 5 of 5. July 1899. - Monomoy Point Light Station, Approximately 3500 feet Northeast Powder Hole Pond, Monomoy National Wildlife Refuge, Chatham, Barnstable County, MA

  5. 17. WEST ELEVATION. MONOMOY POINT LT. STATION, MASS., SHOWING PROPOSED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. WEST ELEVATION. MONOMOY POINT LT. STATION, MASS., SHOWING PROPOSED ALTERATION AND IMPROVEMENT OF DWELLING. No. 1343. Sheet 4 of 5. July 1899. - Monomoy Point Light Station, Approximately 3500 feet Northeast Powder Hole Pond, Monomoy National Wildlife Refuge, Chatham, Barnstable County, MA

  6. 15. SECOND FLOOR PLAN. MONOMOY POINT LT. STATION, MASS., SHOWING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. SECOND FLOOR PLAN. MONOMOY POINT LT. STATION, MASS., SHOWING PROPOSED ALTERATION AND IMPROVEMENT OF DWELLING. No. 1343. SHEET 2 OF 5. July 1899. - Monomoy Point Light Station, Approximately 3500 feet Northeast Powder Hole Pond, Monomoy National Wildlife Refuge, Chatham, Barnstable County, MA

  7. 14. FIRST FLOOR PLAN. MONOMOY POINT LT. STATION, MASS., SHOWING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. FIRST FLOOR PLAN. MONOMOY POINT LT. STATION, MASS., SHOWING PROPOSED ALTERATION AND IMPROVEMENT OF DWELLING. No. 1343. SHEET 1 of 5. July 1899. - Monomoy Point Light Station, Approximately 3500 feet Northeast Powder Hole Pond, Monomoy National Wildlife Refuge, Chatham, Barnstable County, MA

  8. DEMONSTRATION BULLETIN: LOW TEMPERATURE THERMAL TREATMENT (LT3®) SYSTEM

    EPA Science Inventory

    The Roy F. Weston, Inc. (Weston) low temperature thermal treatment (LT3®) system thermally desorbs organic compounds from contaminated soil without heating the soil to combustion temperatures. The transportable system is comprised of equipment assembled on thre...

  9. Unexpected hazards from tephra fallouts at Mt Etna: The 23 November 2013 lava fountain

    NASA Astrophysics Data System (ADS)

    Andronico, Daniele; Scollo, Simona; Cristaldi, Antonio

    2015-10-01

    Hundreds of paroxysmal episodes and a few long-lasting ash-emissions eruptions make Mt. Etna, in Italy, one of the most productive basaltic volcanoes in the world over recent years. This frequent explosive activity certainly gives volcanologists plenty of stimulating scientific material for study. Volcanic hazard from tephra fallout associated with lava fountains is still an issue that has not been fully assessed, albeit having to face this scenario several times in 2013. The 23 November 2013 lava fountain was exceptionally intense despite the short duration of the paroxysmal phase (< 1 h). Abundant decimetric-sized bombs fell within the first 5-6 km from the vent, and a macroscopically thicker and coarser tephra deposit than usual formed between 5 and 25 km; in addition, ash was reported to fall up to distances of 400 km. The analysis of fallout deposit provided a total erupted mass of 1.3 ± 1.1 × 109 kg (for a mass eruption rate of 4.5 ± 3.6 × 105 kg/s), in agreement with the value of 2.4 × 109 kg estimated by modeling. Grain-size distribution of samples shows poor sorting at least up to 25 km from the vent. By comparing dispersal, sedimentological features and physical parameters of the fallout deposit with other lava fountains of Etna, the 23 November 2013 episode may well be one of the largest events of the 21st Century in terms of eruption column height, total erupted mass and mass eruption rate. Furthermore, the impact of tephra on the territory was so high as to make it opportune to introduce a distinction, within the class of lava fountains, between small- and large-scale episodes. This classification can be a starting point for hazard assessment and help prevent the hazards from large-scale lava fountains at Etna in the future.

  10. 7 CFR 28.525 - Symbols and code numbers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... grade Symbol Code No. Good Middling GM 11 Strict Middling SM 21 Middling Mid 31 Strict Low Middling SLM... Middling Light Spotted SLM Lt Sp 42 Low Middling Light Spotted LM Lt Sp 52 Stict Good Ordinary Light... Sp 33 Strict Low Middling Spotted SLM Sp 43 Low Middling Spotted LM Sp 53 Strict Good...

  11. 7 CFR 28.525 - Symbols and code numbers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... grade Symbol Code No. Good Middling GM 11 Strict Middling SM 21 Middling Mid 31 Strict Low Middling SLM... Middling Light Spotted SLM Lt Sp 42 Low Middling Light Spotted LM Lt Sp 52 Stict Good Ordinary Light... Sp 33 Strict Low Middling Spotted SLM Sp 43 Low Middling Spotted LM Sp 53 Strict Good...

  12. 7 CFR 28.525 - Symbols and code numbers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... grade Symbol Code No. Good Middling GM 11 Strict Middling SM 21 Middling Mid 31 Strict Low Middling SLM... Middling Light Spotted SLM Lt Sp 42 Low Middling Light Spotted LM Lt Sp 52 Stict Good Ordinary Light... Sp 33 Strict Low Middling Spotted SLM Sp 43 Low Middling Spotted LM Sp 53 Strict Good...

  13. 7 CFR 28.525 - Symbols and code numbers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... grade Symbol Code No. Good Middling GM 11 Strict Middling SM 21 Middling Mid 31 Strict Low Middling SLM... Middling Light Spotted SLM Lt Sp 42 Low Middling Light Spotted LM Lt Sp 52 Stict Good Ordinary Light... Sp 33 Strict Low Middling Spotted SLM Sp 43 Low Middling Spotted LM Sp 53 Strict Good...

  14. 7 CFR 28.525 - Symbols and code numbers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... grade Symbol Code No. Good Middling GM 11 Strict Middling SM 21 Middling Mid 31 Strict Low Middling SLM... Middling Light Spotted SLM Lt Sp 42 Low Middling Light Spotted LM Lt Sp 52 Stict Good Ordinary Light... Sp 33 Strict Low Middling Spotted SLM Sp 43 Low Middling Spotted LM Sp 53 Strict Good...

  15. Dynamic Fluid-Kinetic (DyFK) Simulations of Storm-Enhanced Density Supply of Cleft Ion Fountain Outflows

    NASA Astrophysics Data System (ADS)

    Horwitz, J. L.; Zeng, W.; Foster, J. C.; Strangeway, R. J.; Adrian, M. L.; Moore, T. E.

    2008-12-01

    Elevated ionospheric density regions frequently appear to be convected from the subauroral plasmaspheric region toward noon, in association with convection of plasmaspheric tails in the dayside magnetosphere, typically during large geomagnetic storms. In this presentation, we explore the possibility that these Storm Enhanced Density (SED) regions could provide ionospheric plasma source populations for cleft ion fountain outflows. We use our Dynamic Fluid Kinetic (DyFK) code to simulate the entry of a high-density "plasmasphere-like" flux tube entering the cleft region and subjected to an episode of wave-driven transverse ion heating. The results of including different proportions of SED and soft electron precipitation levels, together with transverse ion heating effects on the resulting outflows, will be presented, including the O+ and H+ ion density and related parameter profiles for the simulated SED involved events. We will also compare these modeling results with SED-outflow observations from GPS TEC, and the FAST and IMAGE spacecraft. Foster, J. C., P. J. Erickson, A. J. Coster, J. Goldstein, and F. J. Rich, Ionospheric signatures of plasmaspheric tails, Geophys. Res. Lett., 29(13), 1623, doi:10.1029/2002GL015067, 2002.

  16. Doppler radar retrievals from lava fountaining paroxysms generating tephra plumes at Mt. Etna

    NASA Astrophysics Data System (ADS)

    Valentin, Freret-Lorgeril; Franck, Donnadieu; Mauro, Coltelli; Simona, Scollo; Patrick, Fréville; Claude, Hervier; Michele, Prestifilippo

    2016-04-01

    Etna volcano is one of the most active European volcanoes. Between January 2011 and December 2013, a new crater called the New South East Crater (NSEC) was built during 46 eruptive episodes characterized by lava fountaining generating tephra plumes that reached up to 10 km (a.s.l). A 23 cm-wavelength Doppler radar (VOLDORAD 2B), located about 3 km from NSEC at the Montagnola station and integrated into the INGV-OE instrumental network, has been continuously monitoring the explosive activity of Mt. Etna's summit craters since 2009. We have studied these paroxysms by analyzing the radar echoes and Doppler signals coming from adjacent volumes of the fixed beam probing the lava fountains close to the eruptive crater, in combination with thermal and visible imagery. The range gating (150 m-deep probed volumes along-beam) allows us to discriminate the active summit craters and to roughly estimate the lava fountain width. The backscattered power, which is related to the erupted tephra mass load in the beam, and Doppler velocities help to mark the transition from Strombolian activity to lava fountaining, providing onset and end times of the fountain. Both radar parameters directly provide a proxy for the mass eruption rate, which is found to follow the time variations of tephra plume height. Oscillations of the echo power during lava fountaining indicate a pulsatile behavior likely originating in the magmatic conduit or deeper reservoir. Ejection velocities retrieved from positive along-beam velocities measured near the emission source, are found to range from 140 to almost 350 m/s during the climax. Maximum along-beam Doppler velocity components from fallouts allow us to infer maximum particle sizes (pluri-decimetric) in agreement with field observations. The mode of power spectral distribution could further be used to constrain the mean diameter of proximal fallout. A reliable quantification of the source mass loading parameters requires more stringent constraints on the

  17. SEU design consideration for MESFETs on LT GaAs

    SciTech Connect

    Weatherford, T.R.; Radice, R.; Eskins, D.

    1997-12-01

    Computer simulation results are reported on transistor design and single-event charge collection modeling of metal-semiconductor field effect transistors (MESFETs) fabricated in the Vitesse H-GaAsIII{reg_sign} process on Low Temperature grown (LT) GaAs epitaxial layers. Tradeoffs in Single Event Upset (SEU) immunity and transistor design are discussed. Effects due to active loads and diffusion barriers are examined.

  18. Sensitive CO and 13CO survey of water fountain stars. Detections towards IRAS 18460-0151 and IRAS 18596+0315

    NASA Astrophysics Data System (ADS)

    Rizzo, J. R.; Gómez, J. F.; Miranda, L. F.; Osorio, M.; Suárez, O.; Durán-Rojas, M. C.

    2013-12-01

    Context. Water fountain stars represent a stage between the asymptotic giant branch (AGB) and planetary nebulae phases, when the mass loss changes from spherical to bipolar. These types of evolved objects are characterized by high-velocity jets in the 22 GHz water maser emission. Aims: The objective of this work is to detect and study in detail the circumstellar gas in which the bipolar outflows are emerging. The detection and study of thermal lines may help in understanding the nature and physics of the envelopes in which the jets are developing. Methods: We surveyed the CO and 13CO line emission towards a sample of ten water fountain stars through observing the J = 1 → 0 and 2 → 1 lines of CO and 13CO, using the 30 m IRAM radio-telescope at Pico Veleta. All the water fountains visible from the observatory were surveyed. Results: Most of the line emission arises from foreground or background Galactic clouds, and we had to thoroughly analyse the spectra to unveil the velocity components related to the stars. In two sources, IRAS 18460-0151 and IRAS 18596+0315, we identified wide velocity components with a width of 35 - 40 km s-1 that are centred at the stellar velocities. These wide components can be associated with the former AGB envelope of the progenitor star. A third case, IRAS 18286-0959, is reported as tentative; in this case a pair of narrow velocity components, symmetrically located with respect to the stellar velocity, have been discovered. We also modelled the line emission using an LVG code and derived some global physical parameters, which allowed us to discuss the possible origin of this gas in relation to the known bipolar outflows. For IRAS 18460-0151 and IRAS 18596+0315, we derived molecular masses close to 0.2 M⊙, mean densities of 104 cm-3, and mass-loss rates of 10-4 M⊙ yr-1. The kinetic temperatures are rather low, between 10 and 50 K in both cases, which suggests that the CO emission is arising from the outer and cooler regions of the

  19. In situ x-ray diffraction measurements of the capillary fountain jet produced via ultrasonic atomization

    NASA Astrophysics Data System (ADS)

    Yano, Yohko F.; Douguchi, Junya; Kumagai, Atsushi; Iijima, Takao; Tomida, Yukinobu; Miyamoto, Toshiaki; Matsuura, Kazuo

    2006-11-01

    In situ x-ray diffraction measurements were carried out for investigating the liquid structure in the ultrasonic fountain jet to consider the mechanism of the "ultrasonic ethanol separation" reported by Sato et al. [J. Chem. Phys. 114, 2382 (2001)]. For pure liquids (water and ethanol), it was found that the high frequency ultrasound does not affect the liquid structure microscopically. For the 20mol% ethanol-water mixture, the estimated ethanol mole fraction in the ultrasonic fountain jet by using the position of the main maximum in the x-ray diffraction profile coincided with that in the reservoir. This result suggests that the ethanol separation is not caused by any distorted liquid structure under the ultrasound irradiation and occurs when or after the generation of the liquid droplet mist.

  20. In situ x-ray diffraction measurements of the capillary fountain jet produced via ultrasonic atomization.

    PubMed

    Yano, Yohko F; Douguchi, Junya; Kumagai, Atsushi; Iijima, Takao; Tomida, Yukinobu; Miyamoto, Toshiaki; Matsuura, Kazuo

    2006-11-01

    In situ x-ray diffraction measurements were carried out for investigating the liquid structure in the ultrasonic fountain jet to consider the mechanism of the "ultrasonic ethanol separation" reported by Sato et al. [J. Chem. Phys. 114, 2382 (2001)]. For pure liquids (water and ethanol), it was found that the high frequency ultrasound does not affect the liquid structure microscopically. For the 20 mol % ethanol-water mixture, the estimated ethanol mole fraction in the ultrasonic fountain jet by using the position of the main maximum in the x-ray diffraction profile coincided with that in the reservoir. This result suggests that the ethanol separation is not caused by any distorted liquid structure under the ultrasound irradiation and occurs when or after the generation of the liquid droplet mist. PMID:17100459

  1. Euler's friction of fluids theory and the estimation of fountain jet heights

    NASA Astrophysics Data System (ADS)

    Bistafa, Sylvio R.

    2015-09-01

    In 1761, Leonhard Euler (1707-1783) published a treatise with the title "Attempt at a Theory of the Friction of Fluids", in which he assumed that, as is the case for solid friction, fluid friction is proportional to pressure. Several experiments were proposed by Euler to derive a friction factor, which were intended to experimentally confirm his equations. Detailed developments of five different problems of discharge were presented in his treatise, taking into account the loss of head in the conduits. In the Appendix, an example is given of the calculation of the jet heights of a particular fountain, fed with conduits of different cross-sectional areas. Application of the current method for the calculation of head losses in pipes reveals that Euler grossly overestimated the fountain jet heights.

  2. Status of the atomic fountain clock at the National Research Council of Canada

    NASA Astrophysics Data System (ADS)

    Beattie, S.; Alcock, J.; Jian, B.; Gertsvolf, M.; Bernard, J.

    2016-06-01

    Despite the rapid advances in optical frequency standards, caesium fountain clocks retain a critical role as the most accurate primary frequency standards available. At the National Research Council Canada, we are working to develop a second generation caesium fountain clock. Work is currently underway to improve several systems of FCs1, such as the laser system and microwave local oscillator, which will be incorporated into its refurbished version, FCs2. In addition, we have added an optical pumping stage which has increased the detected atom number by over a factor of six. In collaboration with the National Physical Laboratory (NPL), we are planning on replacing the physics package of FCs1. We will report on several recent improvements to FCs1, along with our progress in the development of FCs2.

  3. Focusing a fountain of neutral cesium atoms with an electrostatic lens triplet

    SciTech Connect

    Kalnins, Juris G.; Amini, Jason M.; Gould, Harvey

    2005-10-15

    An electrostatic lens with three focusing elements in an alternating-gradient configuration is used to focus a fountain of cesium atoms in their ground (strong-field-seeking) state. The lens electrodes are shaped to produce only sextupole plus dipole equipotentials which avoids adding the unnecessary nonlinear forces present in cylindrical lenses. Defocusing between lenses is greatly reduced by having all of the main electric fields point in the same direction and be of nearly equal magnitude. The addition of the third lens gave us better control of the focusing strength in the two transverse planes and allowed focusing of the beam to half the image size in both planes. The beam envelope was calculated for lens voltages selected to produced specific focusing properties. The calculations, starting from first principles, were compared with measured beam sizes and found to be in good agreement. Application to fountain experiments, atomic clocks, and focusing polar molecules in strong-field-seeking states is discussed.

  4. Laser Cooling of 87Rb to 1.5 μK in a Fountain Clock

    NASA Astrophysics Data System (ADS)

    Wang, Bin; Lü, De-Sheng; Qu, Qiu-Zhi; Zhao, Jian-Bo; Li, Tang; Liu, Liang; Wang, Yu-Zhu

    2011-06-01

    We report an experiment on the adiabatic cooling of 87Rb atoms in an atomic fountain to a temperature as low as 1.5 μK, which is roughly twice the recoil temperature. The atomic fountain has the (1,1,1) optical geometry for cooling and launching of cold atoms. The atoms are first cooled in an optical molasses of 6 beams to 3.4 μK by polarization gradient geometry and then are adiabatically cooled by decreasing the intensity of laser from 1.8Is per beam to zero in 1 ms during the launching of cold atoms. We also study the dependences of atomic temperature on different laser parameters. The method we used is useful in any cold atom physics experiment.

  5. Light shift measurements in a Cesium Fountain without the use of mechanical shutters

    NASA Technical Reports Server (NTRS)

    Tjoelker, Robert L.; Enzer, D. G.; Klipstein, W. M.

    2005-01-01

    We present measurements confirming operation of a cesium fountain frequency standard with light shift below 10^-15 (and with evidence suggesting it is several orders of magnitude below this level) but without the use of mechanical shutters. Suppression of the light shift is realized using a master-slave laser configuration by reducing the overall optical power delivered to the physics package as well as spoiling the injection of the slave, causing it to lase far off resonance (1-2 nm) as proposed by the authors several years ago [l]. In the absence of any mitigation, this (AC Stark) shift, due to near-resonant laser light reaching the atoms during their microwave interrogation period, is the largest shift in such frequency standards (2x10^-11 for Our fountain). Mechanical shutters provided adequate light attenuation but have been prone to failure.

  6. Training plan for the 1164 {lt}90-day non-radioactive hazardous waste storage building

    SciTech Connect

    Demarest, J.L., Westinghouse Hanford

    1996-07-01

    In accordance with Washington Administrative Code (WAC), Chapter 173- 303, `Dangerous Waste Regulations,` a written training plan is required for a {lt}90-day accumulation area. WAC 173-303-200, `Accumulating Dangerous Waste On-site,` requires compliance with WAC- 173-303-330, Personnel Training. This training plan complies with WAC 173-303-330. This training plan, including the names of personnel in Table 1, may be given to a regulatory agency inspector upon request provided that this plan is cleared for public release. Training records associated with personnel identified in this plan are not be given to an outside regulatory agency inspector unless prior approval by the specific individual is obtained. Training records requests by regulatory agency inspectors without the individual`s approval are to be processed via a Freedom of Information Act request through the U.S. Department of Energy, Richland Operations Office.

  7. Non-Linear Dependence of the Height of a Chain Fountain on Drop Height

    ERIC Educational Resources Information Center

    Andrew, Y.; Kearns, F.; Mustafa, T.; Salih, R.; Ioratim-Uba, A.; Udall, I.; Usama, M.

    2015-01-01

    If the end of a long chain, which is contained in an elevated beaker, is dropped over the edge of the beaker and falls, it is observed that as the speed of the chain increases the chain rises to form a loop well above the top of the beaker. The name "chain fountain" has been applied to this phenomenon. In this study the dependence of the…

  8. Atomic fountain clock with very high frequency stability employing a pulse-tube-cryocooled sapphire oscillator.

    PubMed

    Takamizawa, Akifumi; Yanagimachi, Shinya; Tanabe, Takehiko; Hagimoto, Ken; Hirano, Iku; Watabe, Ken-ichi; Ikegami, Takeshi; Hartnett, John G

    2014-09-01

    The frequency stability of an atomic fountain clock was significantly improved by employing an ultra-stable local oscillator and increasing the number of atoms detected after the Ramsey interrogation, resulting in a measured Allan deviation of 8.3 × 10(-14)τ(-1/2)). A cryogenic sapphire oscillator using an ultra-low-vibration pulse-tube cryocooler and cryostat, without the need for refilling with liquid helium, was applied as a local oscillator and a frequency reference. High atom number was achieved by the high power of the cooling laser beams and optical pumping to the Zeeman sublevel m(F) = 0 employed for a frequency measurement, although vapor-loaded optical molasses with the simple (001) configuration was used for the atomic fountain clock. The resulting stability is not limited by the Dick effect as it is when a BVA quartz oscillator is used as the local oscillator. The stability reached the quantum projection noise limit to within 11%. Using a combination of a cryocooled sapphire oscillator and techniques to enhance the atom number, the frequency stability of any atomic fountain clock, already established as primary frequency standard, may be improved without opening its vacuum chamber. PMID:25167146

  9. NPL Cs fountain frequency standards and the quest for the ultimate accuracy

    NASA Astrophysics Data System (ADS)

    Szymaniec, K.; Lea, S. N.; Gibble, K.; Park, S. E.; Liu, K.; Głowacki, P.

    2016-06-01

    NPL operates a system of two primary caesium fountain clocks consisting of a fully characterised standard NPL-CsF2 together with a new standard NPL-CsF3, which has recently become operational. Both fountains feature a single-stage vapour-loaded magneto-optical trap as the source of cold atoms and an approximate cancellation of the potentially large cold collision frequency shift. As a result, the collision-shift type-B uncertainty is less than 10-16. Subsequently, more subtle systematic effects, including the frequency shifts from distributed cavity phase, microwave lensing and collisions with background gas have also been evaluated at the level of 10-16 or below. Now, as several systematic effects contribute to the fountains’ uncertainty budgets similarly, further significant improvement of their accuracies is expected to be even more difficult. The short-term stability of these standards is also a significant factor limiting the overall precision as many days or even weeks of averaging is required for the type-A statistical uncertainty to approach the declared type-B systematic uncertainty. Going forward, further improvements in the reliability and robustness of operation of fountain standards is one of our priorities.

  10. WATER MASER SURVEY ON AKARI AND IRAS SOURCES: A SEARCH FOR ''LOW-VELOCITY'' WATER FOUNTAINS

    SciTech Connect

    Yung, Bosco H. K.; Nakashima, Jun-ichi; Kwok, Sun; Imai, Hiroshi; Deguchi, Shuji; Henkel, Christian

    2013-05-20

    We present the results of a 22 GHz H{sub 2}O maser survey toward a new sample of asymptotic giant branch (AGB) and post-AGB star candidates. Most of the objects are selected for the first time based on the AKARI data, which have high flux sensitivity in the mid-infrared ranges. We aim at finding H{sub 2}O maser sources in the transient phase between the AGB and post-AGB stages of evolution, where the envelopes start to develop large deviations from spherical symmetry. The observations were carried out with the Effelsberg 100 m radio telescope. Among 204 observed objects, 63 detections (36 new) were obtained. We found four objects that may be ''water fountain'' sources (IRAS 15193+3132, IRAS 18056-1514, OH 16.3-3.0, and IRAS 18455+0448). They possess an H{sub 2}O maser velocity coverage much smaller than those in other known water fountains. However, the coverage is still larger than that of the 1612 MHz OH maser. It implies that there is an outflow with a higher velocity than the envelope expansion velocity (typically {<=}25 km s{sup -1}), meeting the criterion of the water fountain class. We suggest that these candidates are possibly oxygen-rich late AGB or early post-AGB stars in a stage of evolution immediately after the spherically symmetric AGB mass loss has ceased.

  11. The Dynamics of Prolonged Low Fountaining Behaviour at Halemaumau, Kilauea, in December 2013.

    NASA Astrophysics Data System (ADS)

    Houghton, B. F.; Orr, T. R.; Taddeucci, J.; Gonnermann, H. M.; Scarlato, P.; Del Bello, E.; Carey, R.; Patrick, M. R.

    2014-12-01

    Episodes of low-fountaining eruption lasting minutes to tens of minutes alternated with passive degassing at Halema`uma`u during 5 days of observations in December 2013. Some low fountains were triggered by small collapses from the vent walls and originated close to the margin of the lava lake. Others began in the lake interior and migrated to its margins without any obvious link to rock falls. Observations using high-frequency (50-500 Hz) thermal and visible imaging reveal that the fountains consist of sequences of close-spaced, meter-scale pockets of gas that burst through the free surface. Bursts lasted between 0.15 and 1.5 seconds, often partially overlapping in time and space. Bursts entrain both relatively brittle plates from the crust of the lava lake and very ductile thin crust that formed between successive pockets. The latter form spectacular 'lace-work' pyroclasts, of meter-scale diameter, which rise, deform, tear, and fall back into the lava lake. The process can be treated as a form of hydrodynamic fragmentation involving the transformation of masses of accelerating liquid into jets via the generation of liquid films that experience strong stretching during highly non-linear fluid motion.

  12. Similarity and pleasantness assessments of water-fountain sounds recorded in urban public spaces.

    PubMed

    Ekman, Maria Rådsten; Lundén, Peter; Nilsson, Mats E

    2015-11-01

    Water fountains are potential tools for soundscape improvement, but little is known about their perceptual properties. To explore this, sounds were recorded from 32 fountains installed in urban parks. The sounds were recorded with a sound-field microphone and were reproduced using an ambisonic loudspeaker setup. Fifty-seven listeners assessed the sounds with regard to similarity and pleasantness. Multidimensional scaling of similarity data revealed distinct groups of soft variable and loud steady-state sounds. Acoustically, the soft variable sounds were characterized by low overall levels and high temporal variability, whereas the opposite pattern characterized the loud steady-state sounds. The perceived pleasantness of the sounds was negatively related to their overall level and positively related to their temporal variability, whereas spectral centroid was weakly correlated to pleasantness. However, the results of an additional experiment, using the same sounds set equal in overall level, found a negative relationship between pleasantness and spectral centroid, suggesting that spectral factors may influence pleasantness scores in experiments where overall level does not dominate pleasantness assessments. The equal-level experiment also showed that several loud steady-state sounds remained unpleasant, suggesting an inherently unpleasant sound character. From a soundscape design perspective, it may be advisable to avoid fountains generating such sounds. PMID:26627778

  13. Fast Screening of Whole Blood Samples and Pharmaceutical Compounds for Enantiorecognition of Free L-T3 , L-T4 , and D-T4.

    PubMed

    Mitrofan, Grigorina; Stefan-van Staden, Raluca-Ioana; Comnea-Stancu, Ionela Raluca; van Staden, Jacobus Frederick; Bazylak, Grzegorz; Kapnissi-Christodoulou, Constantina P; Aboul-Enein, Hassan Y

    2015-12-01

    A fast screening method of whole blood was proposed for enantiorecognition of free L-T3 , L-T4 , and D-T4 . Stochastic microsensors based on four inulins (IN, IQ, TEX, and HD) immobilized on diamond paste (DP) were used for recognition of free L-T3 , L-T4 , and D-T4 . For the enantiorecognition of free L-T4 and D-T4 in whole blood and pharmaceutical samples, the best microsensor was the one based on TEX/DP (wide linear concentration ranges, and low limits of quantification). The best limit of detection for the assay of free L-T3 (400 fmol/L) was recorded using the microsensors based on HD/DP, while for the assay of free L-T4, and D-T4 the best limit of determination (1 pmol/L) was recorded using the TX/DP-based microsensor. For the enantiorecognition of free L-T3 in whole blood and pharmaceutical samples the best microsensor was the one based on HD/DP (the wider linear concentration range, and the lower limit of quantification - of pmol/L magnitude order). For the enantiorecognition of free L-T3 in whole blood and pharmaceutical samples the best microsensor was the one based on HD/DP (the wider linear concentration range, and the lower limit of quantification - of pmol/L magnitude order). Free L-T3 , L-T4 , and D-T4 were recovered with high reliabilities in whole blood samples (recoveries higher than 99.00%, with RSD values lower than 1.00%) and pharmaceutical samples (recoveries higher than 95.00% with RSD values lower than 1.00%). PMID:26447904

  14. Sliding-window raptor codes for efficient scalable wireless video broadcasting with unequal loss protection.

    PubMed

    Cataldi, Pasquale; Grangetto, Marco; Tillo, Tammam; Magli, Enrico; Olmo, Gabriella

    2010-06-01

    Digital fountain codes have emerged as a low-complexity alternative to Reed-Solomon codes for erasure correction. The applications of these codes are relevant especially in the field of wireless video, where low encoding and decoding complexity is crucial. In this paper, we introduce a new class of digital fountain codes based on a sliding-window approach applied to Raptor codes. These codes have several properties useful for video applications, and provide better performance than classical digital fountains. Then, we propose an application of sliding-window Raptor codes to wireless video broadcasting using scalable video coding. The rates of the base and enhancement layers, as well as the number of coded packets generated for each layer, are optimized so as to yield the best possible expected quality at the receiver side, and providing unequal loss protection to the different layers according to their importance. The proposed system has been validated in a UMTS broadcast scenario, showing that it improves the end-to-end quality, and is robust towards fluctuations in the packet loss rate. PMID:20215084

  15. Eruptive Processes Leading to the Most explosive Lava fountain at Etna Volcano: The 23 November 2013 episode

    NASA Astrophysics Data System (ADS)

    Bonaccorso, Alessandro; Calvari, Sonia

    2015-04-01

    After the end of the last effusive flank eruption on 2008-2009, in January 2011 the eruptive activity resumed at Etna producing a new phase with 44 lava fountain episodes through December 2013. The paroxysmal events took place from a summit vent, the New SE Crater (NSEC), formed on the flank of the SE Crater that in the last few decades was the most active of the summit craters. The 23 November 2013 lava fountain at Etna volcano was the most explosive of these episodes. We infer the total magma volume erupted by thermal images analysis and show that it was characterized by a very high time-averaged-discharge-rate (TADR) of ~360 m^3/s, having erupted ~1.6 × 106 m3 of dense-rock equivalent magma volume in just 45 min, which is more than 3 times the TADR observed during previous episodes. Two borehole dilatometers confirmed the eruption dynamics inferred from the thermal images. When compared to the other lava fountains, this episode can be considered as the explosive end-member. However, the erupted volume was still comparable to the other lava fountain events. We interpret that the 23 November explosive end-member event was caused by more primitive and gas-rich magma entering the system, as demonstrated by the exceptional height reached by the lava fountain.

  16. On the estimation of jet-induced fountain lift and additional suckdown in hover for two-jet configurations

    NASA Technical Reports Server (NTRS)

    Kuhn, Richard E.; Bellavia, David C.; Corsiglia, Victor R.; Wardwell, Douglas A.

    1991-01-01

    Currently available methods for estimating the net suckdown induced on jet V/STOL aircraft hovering in ground effect are based on a correlation of available force data and are, therefore, limited to configurations similar to those in the data base. Experience with some of these configurations has shown that both the fountain lift and additional suckdown are overestimated but these effects cancel each other for configurations within the data base. For other configurations, these effects may not cancel and the net suckdown could be grossly overestimated or underestimated. Also, present methods do not include the prediction of the pitching moments associated with the suckdown induced in ground effect. An attempt to develop a more logically based method for estimating the fountain lift and suckdown based on the jet-induced pressures is initiated. The analysis is based primarily on the data from a related family of three two-jet configurations (all using the same jet spacing) and limited data from two other two-jet configurations. The current status of the method, which includes expressions for estimating the maximum pressure induced in the fountain regions, and the sizes of the fountain and suckdown regions is presented. Correlating factors are developed to be used with these areas and pressures to estimate the fountain lift, the suckdown, and the related pitching moment increments.

  17. Suspended sediment and sediment-source areas in the Fountain Creek drainage basin upstream from Widefield, southeastern Colorado

    USGS Publications Warehouse

    Von Guerard, Paul

    1989-01-01

    Suspended-sediment samples were collected from synoptic-sampling sites to determine suspended-sediment concentrations, loads, yields, and sediment-source areas in the Fountain Creek drainage basin upstream from Widefield, Colorado. Suspended-sediment yields ranged from 0.004 to 278 tons/sq mi/day. Twenty-four sites were sampled that represent urban and rural land use. The median suspended-sediment yield from urban drainage basins was 7.7 tons/sq mi/day and the median suspended-sediment yield from rural drainage basins was 0.46 ton/sq mi/day. Sediment-transport equations were derived for total suspended-sediment discharge and suspended-sand discharge at seven periodic-sampling sites. Annual suspended-sediment loads and yields were computed for the 1985 water year. Urbanization in the downstream parts of the Monument Creek drainage basin, the main tributary to Fountain Creek, affected sediment loads. The downstream 14% of the Monument Creek drainage basin contributed about 61% of the annual suspended-sediment load transported at the mouth of Monument Creek. About 73% of the annual suspended-sediment load for Fountain Creek at Colorado Springs was contributed by Monument Creek. Abandoned mill tailings along Fountain Creek contributed little to total suspended sediment load. Contributions of streambank erosion to basin sediment yields were not quantified. However, the measured rate of streambank erosion at a site on Fountain Creek has increased during a 37-year period. (USGS)

  18. Comparability among four invertebrate sampling methods, Fountain Creek Basin, Colorado, 2010-2012

    USGS Publications Warehouse

    Zuellig, Robert E.; Bruce, James F.; Stogner, Robert W.; Brown, Krystal D.

    2014-01-01

    The U.S. Geological Survey, in cooperation with Colorado Springs City Engineering and Colorado Springs Utilities, designed a study to determine if sampling method and sample timing resulted in comparable samples and assessments of biological condition. To accomplish this task, annual invertebrate samples were collected concurrently using four sampling methods at 15 U.S. Geological Survey streamflow gages in the Fountain Creek basin from 2010 to 2012. Collectively, the four methods are used by local (U.S. Geological Survey cooperative monitoring program) and State monitoring programs (Colorado Department of Public Health and Environment) in the Fountain Creek basin to produce two distinct sample types for each program that target single-and multiple-habitats. This study found distinguishable differences between single-and multi-habitat sample types using both community similarities and multi-metric index values, while methods from each program within sample type were comparable. This indicates that the Colorado Department of Public Health and Environment methods were compatible with the cooperative monitoring program methods within multi-and single-habitat sample types. Comparisons between September and October samples found distinguishable differences based on community similarities for both sample types, whereas only differences were found for single-habitat samples when multi-metric index values were considered. At one site, differences between September and October index values from single-habitat samples resulted in opposing assessments of biological condition. Direct application of the results to inform the revision of the existing Fountain Creek basin U.S. Geological Survey cooperative monitoring program are discussed.

  19. Reticulite, Scoria and Lava: Foam Formation in Hawaiian Fire Fountain Eruptions

    NASA Astrophysics Data System (ADS)

    Rust, A. C.; Cashman, K. V.

    2006-12-01

    Hawaiian fire fountain eruptions can generate three types of foams: 1) scoria pyroclasts characterized by spherical bubbles and typical vesicularities of 70-85%, 2) reticulite pyroclasts consisting of a polygonal network of trigonal glass struts and vesicularities of 95-99% and 3) lava flows with bubble contents as high as 70-80%. We use bubble textures to explore the origins of these three distinct foams. With these data and the observation that all three foam types can erupt simultaneously, we discuss the dynamics of Hawaiian eruptions. Our main focus is reticulite, which is a minor but ubiquitous product of relatively high Hawaiian fountains. Compared to scoria, reticulite is more vesicular and has a larger mean bubble size and a much more uniform bubble size distribution. It was previously suggested that reticulite results from further expansion of hot scoria foam. However, to form reticulite from scoria requires not only that gas expand faster than it can percolate through bubble networks in scoria, but also requires processes such as Ostwald ripening that will reduce the range of bubble sizes. Such processes commonly occur in the formation of polygonal soap foams for instance. However, we suggest that a better analogue for reticulite formation is popcorn. In particular we propose that reticulite did not evolve from scoria but from magma that experienced (1) near-instantaneous bubble nucleation followed by (2) rapid and uniform expansion to generate (3) a polyhedral 'dry' foam that then (4) experienced near-instantaneous film rupture and quenching throughout the foam. In contrast, it seems that there are other parts of the system where bubble nucleation is not instantaneous and yields a broader size distribution of bubbles that expand more slowly, maintain spherical shapes, and become permeable through coalescence of small melt films between spherical bubble walls. We suggest that reticulite only forms in relatively high fire fountains, not because of longer

  20. Design for a fountain of YbF molecules to measure the electron's electric dipole moment

    NASA Astrophysics Data System (ADS)

    Tarbutt, M. R.; Sauer, B. E.; Hudson, J. J.; Hinds, E. A.

    2013-05-01

    We propose an experiment to measure the electric dipole moment (EDM) of the electron using ultracold YbF molecules. The molecules are produced as a thermal beam by a cryogenic buffer gas source, and brought to rest in an optical molasses that cools them to the Doppler limit or below. The molecular cloud is then thrown upward to form a fountain in which the EDM of the electron is measured. A non-zero result would be unambiguous proof of new elementary particle interactions, beyond the standard model.

  1. Simultaneous differential measurement of a magnetic-field gradient by atom interferometry using double fountains

    SciTech Connect

    Hu Zhongkun; Duan Xiaochun; Zhou Minkang; Sun Buliang; Zhao Jinbo; Huang Maomao; Luo Jun

    2011-07-15

    Precisely measuring the magnetic-field gradient within a vacuum chamber is important for many precision experiments and can be realized by atom interferometry using magnetically sensitive sublevels at different times to make a differential measurement, which had been demonstrated in our previous work. In this paper, we demonstrate a differential method to measure the magnetic-field gradient by means of two simultaneously operated atom interferometers using double atomic fountains. By virtue of this simultaneous differential measurement to reject common-mode noise, the resolution can be improved by one order of magnitude for about a 1000-s integration time.

  2. Fountain effect of laser-driven relativistic electrons inside a solid dielectric

    SciTech Connect

    Sarkisov, G. S.; Jobe, D.; Spielman, R.; Leblanc, P.; Ivanov, V. V.; Sentoku, Y.; Yates, K.; Wiewior, P.; Bychenkov, V. Yu.

    2011-09-26

    Ultrafast interferometry with sub-ps resolution has been applied for the direct measurement of an electron density induced by a laser-driven relativistic electron beam inside a solid dielectric. The topology of the interference phase shift shows the signature of the ''fountain effect,'' a narrow electron beam that fans out from the propagation axis and heads back to the target surface. Two-dimensional particle-in-cell (PIC) computer simulations demonstrate radial spreading of fast electrons by self-consistent electrostatic fields. The very low ionization, {approx}0.1%, observed after the heating pulse suggests a fast recombination at the sub-ps time scale.

  3. Selected hydrologic data for Fountain Creek and Monument Creek basins, east-central Colorado

    USGS Publications Warehouse

    Kuhn, Gerhard; Ortiz, Roderick F.

    1989-01-01

    Selected hydrologic data were collected during 1986, 1987, and 1988 by the U.S. Geological Survey for the Fountain Creek and Monument Creek basins, east-central Colorado. The data were obtained as part of a study to determine the present and projected effects of wastewater discharges on the two creeks. The data, which are available for 129 surface-water sites, include: (1) About 1,100 water quality analyses; (2) about 420 measurements of discharge, (3) characteristics of about 50 dye clouds associated with measurements of traveltime and reaeration , and (4) about 360 measurements of channel geometry. (USGS)

  4. The Effects of Crossflow on the Pressures and Lift Induced by the Fountain Generated Between Two Impinging Jets

    NASA Technical Reports Server (NTRS)

    Kuhn, Richard E.

    1998-01-01

    When a jet STOVL aircraft is hovering, or in a crossflow, while close to the ground wall jets flowing radially outward from the impingement points of the jets are generated. An upflow, or fountain, is generated where the wall jets from adjacent jets meet on the ground surface. The induced lift and suckdown generated by the impingement of the fountain on the lower surface of the configuration has been the subject of previous studies. This study analyzes the limited available pressure and force data on the effect of crossflow on the fountain induced lift and suckdown. The analysis includes the effects of jet spacing, height and operating conditions. However, it is limited to twin jet configurations of circular, vertical jets operating at subcritical nozzle pressure ratios over a fixed ground surface.

  5. Eruption dynamics of Hawaiian-style fountains: the case study of episode 1 of the Kīlauea Iki 1959 eruption

    NASA Astrophysics Data System (ADS)

    Stovall, Wendy K.; Houghton, B. F.; Gonnermann, H.; Fagents, S. A.; Swanson, D. A.

    2011-07-01

    Hawaiian eruptions are characterized by fountains of gas and ejecta, sustained for hours to days that reach tens to hundreds of meters in height. Quantitative analysis of the pyroclastic products from the 1959 eruption of Kīlauea Iki, Kīlauea volcano, Hawai`i, provides insights into the processes occurring during typical Hawaiian fountaining activity. This short-lived but powerful eruption contained 17 fountaining episodes and produced a cone and tephra blanket as well as a lava lake that interacted with the vent and fountain during all but the first episode of the eruption, the focus of this paper. Microtextural analysis of Hawaiian fountaining products from this opening episode is used to infer vesiculation processes within the fountain and shallow conduit. Vesicle number densities for all clasts are high (106-107 cm-3). Post-fragmentation expansion of bubbles within the thermally-insulated fountain overprints the pre-fragmentation bubble populations, leading to a reduction in vesicle number density and increase in mean vesicle size. However, early quenched rims of some clasts, with vesicle number densities approaching 107 cm-3, are probably a valid approximation to magma conditions near fragmentation. The extent of clast evolution from low vesicle-to-melt ratio and corresponding high vesicle number density to higher vesicle-to-melt ratio and lower vesicle-number density corresponds to the length of residence time within the fountain.

  6. Density, Grain-size, and Vesicle Analysis of Hawaiian Fountains During the 1969 Mauna Ulu Eruption at Kilauea

    NASA Astrophysics Data System (ADS)

    Parcheta, C. E.; Houghton, B. F.; Swanson, D.

    2011-12-01

    Fountains from the Mauna Ulu eruption in 1969 produced a tephra cone and blanket similar in size to that of Kilauea Iki a decade earlier. The 12 episodes from the eruption displayed a range of fountain behaviors, from low fissure fountains on May 24 (episode 1) to high paired and single circular-sourced fountains in episodes 2 through 12. The highest fountain from this eruption was during the 9-hr long episode 9 (Sep 6-7), and reached 540 m, the second highest fountain recorded at Kilauea. Differences in the vigor and eruption style of these Hawaiian fountains are broadly related to the gas content driving magma ascent through the plumbing system in the east rift zone and the rate and timing of exsolution of this gas. While the tephra cone is now buried under 70 m of a lava shield, and lava flows cover the eastern half of the tephra blanket, the western half of the tephra blanket is still exposed. The nearest possible sample location to the vent is 1.7 km SW of the summit of Mauna Ulu. Transects across (east to west) and down (north to south) the wind direction were made to obtain a partial data set for the Mauna Ulu tephra remaining on the surface. Density, grain-size, and vesicle analysis was performed for a complete stratigraphic column recreated with the crosswind transect data; maximum class dimensions were measured in downwind pits. Median density shifts and the occurrence of bimodal density samples suggest gradual outgassing of the whole system with at least one injection of gas-rich material coming into the system during the seven months of eruption in 1969. Median grain-size is consistent at -2.5 to -2.0 phi. Polished thin sections show microlites in some pyroclasts, which may indicate magma mixing (also suggested in Swanson et al., 1979) either with previously erupted and recycled material from the Mauna Ulu eruption or a second magma source stored in the easternmost portion of the Koa'e fault system. We present here new data on vesicle number density and

  7. Shrinking galaxy disks with fountain-driven accretion from the halo

    SciTech Connect

    Elmegreen, Bruce G.; Struck, Curtis; Hunter, Deidre A. E-mail: curt@iastate.edu

    2014-12-01

    Star formation in most galaxies requires cosmic gas accretion because the gas consumption time is short compared to the Hubble time. This accretion presumably comes from a combination of infalling satellite debris, cold flows, and condensation of hot halo gas at the cool disk interface, perhaps aided by a galactic fountain. In general, the accretion will have a different specific angular momentum than the part of the disk that receives it, even if the gas comes from the nearby halo. The gas disk then expands or shrinks over time. Here we show that condensation of halo gas at a rate proportional to the star formation rate in the fountain model will preserve an initial shape, such as an exponential, with a shrinking scale length, leaving behind a stellar disk with a slightly steeper profile of younger stars near the center. This process is slow for most galaxies, producing imperceptible radial speeds, and it may be dominated by other torques, but it could be important for blue compact dwarfs, which tend to have large, irregular gas reservoirs and steep blue profiles in their inner stellar disks.

  8. ALMA Reveals a Galaxy-Scale Fountain of Cold Molecular Gas Pumped by a Black Hole

    NASA Astrophysics Data System (ADS)

    Tremblay, Grant

    2016-01-01

    A new ALMA observation of the cool core brightest cluster galaxy in Abell 2597 reveals that a supermassive black hole can act much like a mechanical pump in a water fountain, driving a convective flow of molecular gas that drains into the black hole accretion reservoir, only to be pushed outward again in a jet-driven outflow that then rains back toward the galaxy center from which it came. The ALMA data reveal "shadows" cast by giant molecular clouds falling on ballistic trajectories towards the black hole in the innermost 500 parsecs of the galaxy, manifesting as deep redshifted continuum absorption features. The black hole accretion reservoir, fueled by these infalling cold clouds, powers an AGN that drives a jet-driven molecular outflow in the form of a 10 kpc-scale, billion solar mass expanding molecular bubble or plume. The molecular shell is permeated with young stars, perhaps triggered in situ by the jet. Buoyant X-ray cavities excavated by the propagating radio source may further uplift the molecular filaments, which are observed to fall inward toward the center of the galaxy from which they came, presumably keeping the fountain long-lived. The results show that cold molecular gas can couple to black hole growth via both feedback and feeding, in alignment with "cold chaotic accretion" models for the regulation of star formation in galaxies.

  9. The First Water Fountain in a Planetary Nebula with Synchrotron Emission

    NASA Astrophysics Data System (ADS)

    Suárez, O.; Gómez, J. F.; Bendjoya, Ph.; Miranda, L. F.; Guerrero, M. A.; Uscanga, L.; Green, J. A.; Rizzo, J. R.; Ramos-Larios, G.

    2015-12-01

    Planetary nebulae (PNe) show a great variety of morphologies at optical wavelengths that might be due to the effects of jets (Sahai & Trauger [8]) and where magnetic fields might also play an important role. The special class of "water fountain" stars, showing high-velocity, collimated jets traced by water maser emission are key objects to understand the transition to the PN phase and the effect of the jets. IRAS 15103-5754 has been revealed as the youngest PN known, caught just at its birth. It is the first PN that shows water fountain characteristics (Gómez et al. [5]), and it shows, for the first time, direct evidence of the presence of synchrotron emission in a PN, tracing energetic, magnetized shocks (Suárez et al. [9]). Moreover, we observed a sudden change in the spectral distribution of its radio continuum emission, which marks the fast, recent passage of the ionization front over the radio-emitting region (Suárez et al. [9]).

  10. The impact of galactic fountains on the global evolution of galaxy disks

    NASA Astrophysics Data System (ADS)

    Fraternali, F.

    2016-06-01

    The evolution of the Milky Way, and its thin disc in particular, is a history of continuous accretion of fresh gas from the surrounding environment. Evidence for this accretion taking place include high-velocity clouds (HVCs) that appear to be raining down from the halo. I present a model that explains the formation of the prototypical HVC Complex C as gas cooling of the Galactic corona triggered by the explosion of a superbubble in the Outer arm occurred 150 Myr ago. This result is obtained with a new galactic fountain model combined with high-resolution hydrodynamical simulations. The material ejected by the superbubble has triggered the condensation of a large portion of the circumgalactic medium and caused its subsequent accretion on to the disc. This is a local manifestation of fountain-driven cooling of the lower Galactic corona that can contribute significantly in brining fresh low-metallicity gas to the disc of our Galaxy. The same model also reproduces the global-scale kinematics of the extraplanar gas and predicts a gas accretion that evolves inside-out.

  11. Evidences of increasing primary production in the ocean by Stommel's perpetual salt fountain

    NASA Astrophysics Data System (ADS)

    Maruyama, Shigenao; Yabuki, Takashi; Sato, Tetsuya; Tsubaki, Koutaro; Komiya, Atsuki; Watanabe, Mikihito; Kawamura, Hiroshi; Tsukamoto, Katsumi

    2011-05-01

    The American physical oceanographer Henry Stommel and co-workers proposed "the perpetual salt fountain" and suggested the possibility of upwelling deep seawater without an energy source. In the open ocean, deep seawater containing rich nutrients becomes a source of primary production. Previously, we have tested Stommel's hypothesis by numerical simulations and in ocean experiments, and confirmed the upwelling of a perpetual salt fountain. In the present study, we conducted an open-ocean experiment in the Philippines Sea, and succeeded to demonstrate an increase in chlorophyll concentration. The chlorophyll concentration at the pipe outlet was much greater than that in the surrounding seawater. Satellite ocean-color image around the pipe was analyzed, and the signal of artificial upwelling is investigated. Composite analysis of satellite chlorophyll image indicates an increased surface chlorophyll distribution in the vicinity of pipe position, in which the increasing signal is much larger than the expected production based on nutrient supply. Although the problem must be further discussed, this increased signal is shown to be statistically significant. This mechanism may contribute to effective utilization of fishery resources in subtropical oligotrophic region.

  12. Proposal of a truncated atomic beam fountain for reduction of collisional frequency shift

    SciTech Connect

    Takamizawa, A.; Yanagimachi, S.; Ikegami, T.; Shirakawa, Y.

    2010-07-15

    We propose an atomic fountain clock with a truncated cold atomic beam to achieve both a low collisional frequency shift and high frequency stability. In this clock, the launching velocity of a cold atomic beam can be swept to reduce the atomic density in the interrogation region for the Ramsey resonance and to increase the atomic density in the detection region. Before the top of the beam arrives at the interrogation region, the cold atomic beam is truncated by turning off the cooling laser beams to remove the unnecessary light shift. The atomic density in the interrogation region is theoretically evaluated to be 0.04 times that in an ordinary atomic fountain with optical molasses for the same number of detected atoms. The frequency stability limit due to quantum projection noise is calculated to reach 6.4x10{sup -14} in 1 s from the number of detected atoms while the fractional collisional shift is estimated to be {approx}{sup -}2x10{sup -16}.

  13. A User's Manual for ROTTILT Solver: Tiltrotor Fountain Flow Field Prediction

    NASA Technical Reports Server (NTRS)

    Tadghighi, Hormoz; Rajagopalan, R. Ganesh

    1999-01-01

    A CFD solver has been developed to provide the time averaged details of the fountain flow typical for tiltrotor aircraft in hover. This Navier-Stokes solver, designated as ROTTILT, assumes the 3-D fountain flowfield to be steady and incompressible. The theoretical background is described in this manual. In order to enable the rotor trim solution in the presence of tiltrotor aircraft components such as wing, nacelle, and fuselage, the solver is coupled with a set of trim routines which are highly efficient in CPU and suitable for CFD analysis. The Cartesian grid technique utilized provides the user with a unique capability for insertion or elimination of any components of the bodies considered for a given tiltrotor aircraft configuration. The flowfield associated with either a semi or full-span configuration can be computed through user options in the ROTTILT input file. Full details associated with the numerical solution implemented in ROTTILT and assumptions are presented. A description of input surface mesh topology is provided in the appendices along with a listing of all preprocessor programs. Input variable definitions and default values are provided for the V22 aircraft. Limited predicted results using the coupled ROTTILT/WOPWOP program for the V22 in hover are made and compared with measurement. To visualize the V22 aircraft and predictions, a preprocessor graphics program GNU-PLOT3D was used. This program is described and example graphic results presented.

  14. Remediation scenarios for attenuating peak flows and reducing sediment transport in Fountain Creek, Colorado, 2013

    USGS Publications Warehouse

    Kohn, Michael S.; Fulton, John W.; Williams, Cory A.; Stogner, Robert W.

    2014-01-01

    The U.S. Geological Survey (USGS) in cooperation with the Fountain Creek Watershed, Flood Control and Greenway District assessed remediation scenarios to attenuate peak flows and reduce sediment loads in the Fountain Creek watershed. To evaluate these strategies, the U.S. Army Corps of Engineers Hydrologic Engineering Center (HEC) hydrologic and hydraulic models were employed. The U.S. Army Corps of Engineers modeling system HEC-HMS (Hydrologic Modeling System) version 3.5 was used to simulate runoff in the Fountain Creek watershed, Colorado, associated with storms of varying magnitude and duration. Rain-gage precipitation data and radar-based precipitation data from the April 28–30, 1999, and September 14–15, 2011, storm events were used in the calibration process for the HEC-HMS model. The curve number and lag time for each subwatershed and Manning's roughness coefficients for each channel reach were adjusted within an acceptable range so that the simulated and measured streamflow hydrographs for each of the 12 USGS streamgages approximated each other. The U.S. Army Corps of Engineers modeling system HEC-RAS (River Analysis System) versions 4.1 and 4.2 were used to simulate streamflow and sediment transport, respectively, for the Fountain Creek watershed generated by a particular storm event. Data from 15 USGS streamgages were used for model calibration and 7 of those USGS streamgages were used for model validation. The calibration process consisted of comparing the simulated water-surface elevations and the cross-section-averaged velocities from the model with those surveyed in the field at the cross section at the corresponding 15 and 7 streamgages, respectively. The final Manning’s roughness coefficients were adjusted between –30 and 30 percent at the 15 calibration streamgages from the original left, right, and channel-averaged Manning's roughness coefficients upon completion of calibration. The U.S. Army Corps of Engineers modeling system HEC

  15. SuperLab LT: Evaluation and Uses in Teaching Experimental Psychology

    ERIC Educational Resources Information Center

    Ragozzine, Frank

    2002-01-01

    I describe and evaluate SuperLab LT (Chase & Abboud, 1990), a software package that enables students to replicate classic experiments in cognitive psychology. I also discuss the package with respect to its uses in teaching an undergraduate course in Experimental Psychology. Although the package has minor flaws, SuperLab LT provides numerous…

  16. Loss Reduction on Adoption of High Voltage LT Less Distribution

    NASA Astrophysics Data System (ADS)

    Tiwari, Deepika; Adhikari, Nikhileshwar Prasad; Gupta, Amit; Bajpai, Santosh Kumar

    2015-03-01

    In India there is a need to improve the quality of the electricity distribution process which has increased varying from year to year. In distribution networks, the limiting factor to load carrying capacity is generally the voltage reduction. High voltage distribution system (HVDS) is one of the steps to reduce line losses in electrical distribution network. It helps to reduce the length of low tension (LT) lines and makes the power available close to the users. The high voltage power distribution system reduces the probability of power theft by hooking HVDS suggests an increase in installation of small capacity single-phase transformers in the network which again save considerable energy. This paper is compared to existing conventional low tension distribution network with HVDS. The paper gives a clear picture of reduction in distribution losses with adoption of HVDS system. Losses Reduction of 11 kV Feeder in Nuniya (India) with adoption of HVDS have been worked out/ quantified and benefits thereby in generating capacity have discussed.

  17. Loss Reduction on Adoption of High Voltage LT Less Distribution

    NASA Astrophysics Data System (ADS)

    Tiwari, Deepika; Adhikari, Nikhileshwar Prasad; Gupta, Amit; Bajpai, Santosh Kumar

    2016-06-01

    In India there is a need to improve the quality of the electricity distribution process which has increased varying from year to year. In distribution networks, the limiting factor to load carrying capacity is generally the voltage reduction. High voltage distribution system (HVDS) is one of the steps to reduce line losses in electrical distribution network. It helps to reduce the length of low tension (LT) lines and makes the power available close to the users. The high voltage power distribution system reduces the probability of power theft by hooking HVDS suggests an increase in installation of small capacity single-phase transformers in the network which again save considerable energy. This paper is compared to existing conventional low tension distribution network with HVDS. The paper gives a clear picture of reduction in distribution losses with adoption of HVDS system. Losses Reduction of 11 kV Feeder in Nuniya (India) with adoption of HVDS have been worked out/ quantified and benefits thereby in generating capacity have discussed.

  18. Identification and dating of the fountain pen ink entries on documents by ion-pairing high-performance liquid chromatography.

    PubMed

    Wang, Xiang-Feng; Yu, Jing; Xie, Meng-Xia; Yao, Ya-Tong; Han, Jie

    2008-08-25

    A novel approach for the identification and dating of the fountain pen ink entries on paper has been established by ion-pairing high-performance liquid chromatography (IP-HPLC). Twelve black and six red fountain inks have been collected, and their ink entries have been prepared by drawing lines on paper. The chromatographic conditions for separation of their dye components after extraction with solvents were optimized. Under the optimized conditions, the 18 fountain pen inks were differentiated individually by comparing the number of detectable main or minor dye components, and the relative peak intensities of each component. The ink entries were artificially and naturally aged, and the analysis results showed that the ink dye components were significantly decomposed when exposed to UV or fluorescent light compare to those of inks stored under natural condition. The changes of the relative peak height for the dye components were linearly related to the aging time, especially under natural aging conditions. The degradation characteristics of the dye components under different aging conditions provide scientific evidences for dating of the suspicious fountain pen ink entries on document. PMID:18703295

  19. Merit Pay in Arkansas: An Evaluation of the Cobra Pride Incentive Program in the Fountain Lake School District

    ERIC Educational Resources Information Center

    Jensen, Nathan C.

    2012-01-01

    Starting in the 2010-11, administrators at the Fountain Lake School District implemented the Cobra Pride Incentive Program (CPIP), a merit pay program designed to financially reward all school employees with year-end bonuses primarily for significant improvements in student achievement. At the conclusion of the 2010-11 school year, over $800,000…

  20. Regulation of L-arabinose transport in Salmonella typhimurium LT2.

    PubMed

    Lee, J H; Russo, R J; Heffernan, L; Wilcox, G

    1982-01-01

    The inducible L-arabinose transport system was characterized in Salmonella typhimurium LT2. Only one L-arabinose transport system with a Km of 2 X 10(-4) M was identified. The results suggested that araE may be the only gene which codes for L-arabinose transport activity under the conditions tested. An araE-lac fusion strain was used to study the induction of the araE gene. No araE expression was detected when the L-arabinose concentration was lower than 1 mM. The expression of araE reached a maximum in the presence of 50 mM L-arabinose, and was significantly reduced in the presence of 50 mM L-arabinose, and was significantly reduced in the presence of D-glucose. Expression of the araBAD and araE genes was coordinately regulated. The concentration of L-arabinose that allowed maximum araBAD gene expression was 50-fold lower in an araE+ strain compared to an araE strain. PMID:6283309

  1. Modeling ash dispersal of the 23 February 2013 Etna lava fountain

    NASA Astrophysics Data System (ADS)

    Poret, Matthieu; Costa, Antonio; Andronico, Daniele; Scollo, Simona; Gouhier, Mathieu

    2016-04-01

    Most plumes generated by explosive eruptions from Mt. Etna, Italy, are affected by winds towards East driving volcanic ash over the sea. It implies that erupted tephra can be collected only at proximal area around the volcano, i.e. within 20-25 km. It follows that the quantification of fine ash component and the Total Grain Size Distribution (TGSD) are very difficult and highly uncertain. Among the five lava fountain episodes occurred on the New South-East Crater of Mt. Etna, from the 17 to 23 February 2013, the 23 February paroxysmal phase lasted 1 hour and produced magma jets higher than 500 m and an eruptive plume that reached ~9 km above sea level. Winds oriented toward North-East advected the plume and produced an extended tephra fallout deposit from the slope of Etna up to Puglia region (~ 400 km from the volcano), allowing lapilli and ash to be sampled at different locations. Here, we first estimate the TGSD and the fine ash content associated to 12 samples collected after the paroxysmal episode over the entire tephra blanket. The TGSD is compared with the one related to the 12-13 January 2011 lava fountain showing a similar distribution with a mode around phi = -3. Satellite data describing the evolution of PM10 from the vent up to Calabria region were used to quantify the tail of the distribution and the fraction of the very fine ash. In order to reproduce both the field and spaceborne (MSG-SEVIRI) observations we simulated the tephra dispersal using the computational model Fall3D after modifying the TGSD by adding the fine ash component empirically. A set of simulations allowed us to assess key volcanological parameters such as the column height, the mass distribution within the plume and the effective TGSD. Best fit results indicate a Mass Eruption Rate around 1.0d+6 kg/s, a Total Erupted Mass of about 3.8d+9 kg and a PM10 fraction of ~0.73% respect to the total mass. Results lead the 23 February 2013 lava fountain episode as one of the most intense in

  2. Pharmacological characterization of conotoxin lt14a as a potent non-addictive analgesic.

    PubMed

    Ren, Zhenghua; Wang, Lei; Qin, Mengying; You, Yuwen; Pan, Wuguang; Zhou, Liang; Sun, Dandan; Xu, Anlong

    2015-03-01

    Conotoxin lt14a is a small peptide consisting of 13 amino acids. It was originally identified from the cDNA of Conus litteratus in the South China Sea. Previous reports showed lt14a exhibited antinociceptive activity using a hot plate-induced pain mouse model and acted as an antagonist of neuronal nicotinic acetylcholine receptors. We confirmed that conotoxin lt14a administration resulted in antinociception activity using a mouse inflammatory pain model and a rat model of mechanically-induced pain. The mRNA expression of c-fos and NOS in the spinal cord of rats was suppressed by lt14a. Labeling of lt14a with an Alexa Fluor 488 ester showed that lt14a was bound to the surface of PC12 cells and that this binding was inhibited by pre-application of the nicotinic acetylcholine receptor (nAChR) antagonist tubocurarine chloride (TUB) and the nAChR blocker hexamethonium bromide (HB). These data confirm previous reports that showed lt14a binds to the surface of PC12 cells via nAChRs with patch clamp whole-cell recordings. Additional results showed that lt14a suppressed extracellular signal-regulated kinase (ERK1/2) phosphorylation in PC12 cells activated by Ach. Our results showed that lt14a did not induce drug dependence but rather suppressed morphine withdrawal symptoms. Our work suggests that lt14a is a novel antinociceptive agent that targets the nAChR receptor without inducing drug dependence. PMID:25617597

  3. Cholera toxin, LT-I, LT-IIa, and LT-IIb: the critical role of ganglioside-binding in immunomodulation by Type I and Type II heat-labile enterotoxins

    PubMed Central

    Connell, Terry D.

    2010-01-01

    The heat-labile enterotoxins (HLT) expressed by Vibrio cholerae (cholera toxin) and Escherichia coli (LT-I, LT-IIa, and LT-IIb) are potent systemic and mucosal adjuvants. Co-administration of the enterotoxins with a foreign antigen (Ag) produces an augmented immune response to that antigen. Although each enterotoxin has potent adjuvant properties, the means by which the enterotoxins induce various immune responses are distinctive for each adjuvant. Various mutants have been engineered to dissect the functions of the enterotoxins required for their adjuvanticity. The capacity to strongly bind to one or more specific ganglioside receptors appears to drive the distinctive immunomodulatory properties associated with each enterotoxin. Mutant enterotoxins with ablated or altered ganglioside binding affinities have been employed to investigate the role of gangliosides in enterotoxin-dependent immunomodulation. PMID:17931161

  4. Suckdown, fountain lift, and pressures induced on several tandem jet V/STOL configurations

    NASA Technical Reports Server (NTRS)

    Bellavia, David C.; Wardwell, Douglas A.; Corsiglia, Victor R.; Kuhn, Richard E.

    1991-01-01

    As part of a program to improve the methods for predicting the suckdown and hot gas ingestion for jet V/STOL aircraft in ground effect, a data base is being created that provides a systematic variation of parameters so that a new empirical prediction procedure can be developed. The first series of tests in this program was completed. Suckdown, fountain lift, and pressures induced on several two-jet V/STOL configurations are described. It is one of three reports that present the data obtained from tests conducted at Lockheed Aeronautical Systems-Rye Canyon Facility and in the High Bay area of the 40 by 80 foot wind tunnel complex at NASA Ames Research Center.

  5. Darcy's Public Fountains of the City of Dijon, Past and Present

    NASA Astrophysics Data System (ADS)

    Bobeck, P.; Ritzi, R. W.; Bair, E. S.

    2006-12-01

    Les Fountaines Publiques de la Ville de Dijon (Darcy, 1856) is well known for introducing the equation of ground-water motion. The monograph is a summary of Darcy's career-long study of hydraulics including water flow in canals, aqueducts, pipes, sand filters, and ground-water wells. He presented his knowledge in these areas in reviewing his construction of the public water supply system for Dijon, a system completed in 1840. The authors have recently traveled the length of Darcy's aqueduct system from its source at Rosoir spring, to the Porte Guillaume reservoir (at Jardin Darcy as it enters Dijon), through the city, to the terminal reservoir. We present the state of Darcy's original aqueduct (no longer in use) and public water supply system, and compare his design to the modern public water supply system serving Dijon.

  6. Effect of turbulent fluctuations on the behaviour of fountains in stratified environments

    NASA Astrophysics Data System (ADS)

    Freire, D.; Cabeza, C.; Pauletti, S.; Sarasúa, G.; Bove, I.; Usera, G.; Martí, A. C.

    2010-09-01

    The interaction between a turbulent fountain and its stratified environment was studied. A heavy fluid, cold water, was injected vertically upwards into a linearly stratified medium. The round heavy-fluid jet reaches a maximum height before it begins to fall due to the effect of gravity. Because of the effects of friction and mixing, the vertical momentum and density of the jet fluid decrease as it submerges to an intermediate height of zero buoyancy. At this point, the jet fluid spreads as a horizontal front, intruding into the stratified environment. The degree of fluctuation in the proximity of the injection point was studied under both unrestricted- and restricted-flow configurations at the injection, using two differently sized stainless-steel woven-wire screens at the injection port as flow-restricting means. Using visualization and velocimetry techniques, both maximum and spreading heights were found to decrease with increasing turbulence at the point of injection.

  7. Magma mixing and high fountaining during the 1959 Kīlauea Iki eruption, Hawai‘i

    USGS Publications Warehouse

    Sides, I.; Edmonds, M.; Maclennan, J.; Houghton, B. F.; Swanson, Don; Steele-MacInnis, M.J.

    2014-01-01

    The 1959 Kīlauea Iki eruption provides a unique opportunity to investigate the process of shallow magma mixing, its impact on the magmatic volatile budget and its role in triggering and driving episodes of Hawaiian fountaining. Melt inclusions hosted by olivine record a continuous decrease in H2O concentration through the 17 episodes of the eruption, while CO2 concentrations correlate with the degree of post-entrapment crystallization of olivine on the inclusion walls. Geochemical data, when combined with the magma budget and with contemporaneous eruption observations, show complex mixing between episodes involving hot, geochemically heterogeneous melts from depth, likely carrying exsolved vapor, and melts which had erupted at the surface, degassed and drained-back into the vent. The drained-back melts acted as a coolant, inducing rapid cooling of the more primitive melts and their olivines at shallow depths and inducing crystallization and vesiculation and triggering renewed fountaining. A consequence of the mixing is that the melts became vapor-undersaturated, so equilibration pressures cannot be inferred from them using saturation models. After the melt inclusions were trapped, continued growth of vapor bubbles, caused by enhanced post-entrapment crystallization, sequestered a large fraction of CO2 from the melt within the inclusions. This study, while cautioning against accepting melt inclusion CO2 concentrations “as measured” in mixed magmas, also illustrates that careful analysis and interpretation of post-entrapment modifications can turn this apparent challenge into a way to yield novel useful insights into the geochemical controls on eruption intensity.

  8. Bioaccumulation of Selenium by the Bryophyte Hygrohypnum ochraceum in the Fountain Creek Watershed, Colorado

    NASA Astrophysics Data System (ADS)

    Herrmann, S. J.; Turner, J. A.; Carsella, J. S.; Lehmpuhl, D. W.; Nimmo, D. R.

    2012-12-01

    Aquatic bryophytes, Hygrohypnum ochraceum, were deployed "in situ" at 14 sites in the Fountain Creek Watershed, spring and fall, 2007 to study selenium (Se) accumulation. Dissolved, total, and pore (sediment derived) water samples were collected and water quality parameters determined while plants were exposed to the water for 10 days. There was a trend showing plant tissue-Se uptake with distance downstream and we found a strong correlation between Se in the water with total hardness in both seasons. There was a modest association between Se-uptake in plants with hardness in the spring of 2007 but not the fall. Plants bioconcentrated Se from the water by a factor of 5.8 × 103 at Green Mountain Falls and 1.5 × 104 at Manitou Springs in the fall of 2007. Both are examples of the bioconcentration abilities of the plants, primarily in the upper reaches of the watershed where bioconcentration factors were highest. However, the mean minima and maxima of Se in the plants in each of the three watershed segments appeared similar during both seasons. We found direct relationships between the pore and dissolved Se in water in the spring ( R 2 = 0.84) and fall ( R 2 = 0.95) and dissolved Se and total hardness in the spring and fall ( R 2 = 0.92). The data indicate that H. ochraceum was a suitable indicator of Se bioavailability and Se uptake in other trophic levels in the Fountain Creek Watershed based on a subsequent study of Se accumulation in fish tissues at all 14 sites.

  9. Mercury and selenium in fish of Fountain Creek, Colorado (USA): possible sources and implications.

    PubMed

    Nimmo, D R; Herrmann, S J; Carsella, J S; McGarvy, C M; Foutz, H P; Herrmann-Hoesing, L M; Gregorich, J M; Turner, J A; Vanden Heuvel, B D

    2016-01-01

    Fountain Creek in Colorado USA is a major tributary that confluences with the Arkansas River at Pueblo, Colorado, the result being the tributary's influence on Arkansas River water quality affecting down-stream users. In a previous study, we found that bryophytes (aquatic plants) accumulated selenium in Fountain Creek watershed and this finding prompted us to investigate the extent of the metalloid in the whole-body tissues of fish. One hundred 11 fish (six species) were collected and analyzed for Se by inductively-coupled plasma emission mass spectrometry. Analysis of all analytical data also showed mercury in all of the fish whole bodies and selected tissues. There was a general increase in selenium but a decrease in mercury in fish with downstream travel-distance. The highest whole-body selenium was in Pueblo, Colorado (3393 µg/kg, dry weight; 906 µg/kg, wet weight); the highest mercury in fish was in the Monument Creek tributary north of Colorado Springs, Colorado (71 µg/kg, dry weight; 19 µg/kg, wet weight). In four tissues of 11 female fish captured, selenium was highest in the livers at eight sites but highest in the ovaries at three sites. Mercury was highest in the epaxial muscle at all sites. Selenium availability could be due to the watershed lithology and land uses; however, mercury could be carried by atmospheric deposition from coal-fired power plants and historic mining activities. Selenium in fish tissues and water samples were compared to U.S. national water quality criteria. PMID:27104125

  10. Obscuring Fraction of Active Galactic Nuclei: Implications from Radiation-driven Fountain Models

    NASA Astrophysics Data System (ADS)

    Wada, Keiichi

    2015-10-01

    Active galactic nuclei (AGNs) are believed to be obscured by an optical thick “torus” that covers a large fraction of solid angles for the nuclei. However, the physical origin of the tori and the differences in the tori among AGNs are not clear. In a previous paper based on three-dimensional radiation-hydorodynamic calculations, we proposed a physics-based mechanism for the obscuration, called “radiation-driven fountains,” in which the circulation of the gas driven by central radiation naturally forms a thick disk that partially obscures the nuclear emission. Here, we expand this mechanism and conduct a series of simulations to explore how obscuration depends on the properties of AGNs. We found that the obscuring fraction fobs for a given column density toward the AGNs changes depending on both the AGN luminosity and the black hole mass. In particular, fobs for NH ≥ 1022 cm-2 increases from ˜0.2 to ˜0.6 as a function of the X-ray luminosity LX in the LX = 1042-44 erg s-1 range, but fobs becomes small (˜0.4) above a luminosity (˜1045 erg s-1). The behaviors of fobs can be understood by a simple analytic model and provide insight into the redshift evolution of the obscuration. The simulations also show that for a given LAGN, fobs is always smaller (˜0.2-0.3) for a larger column density (NH ≥ 1023 cm-2). We also found cases that more than 70% of the solid angles can be covered by the fountain flows.

  11. From the ashes: JVLA observations of water fountain nebula candidates show the rebirth of IRAS 18455+0448

    NASA Astrophysics Data System (ADS)

    Vlemmings, W. H. T.; Amiri, N.; van Langevelde, H. J.; Tafoya, D.

    2014-09-01

    Context. The class of water fountain nebulae is thought to represent the stage of the earliest onset of collimated bipolar outflows during the post-asymptotic giant branch phase. They thus play a crucial role in the study of the formation of bipolar planetary nebulae (PNe). To date, 14 water fountain nebulae have been identified. The identification of more sources in this unique stage of stellar evolution will enable us to study the origin of bipolar PNe morphologies in more detail. Aims: Water fountain candidates can be identified based on the often double peaked 22 GHz H2O maser spectrum with a large separation between the maser peaks (often >100 km s-1). However, even a fast bipolar outflow will only have a moderate velocity extent in its maser spectrum when located close to the plane of the sky. In this project we aim to enhance the water fountain sample by identifying objects whose jets are aligned close to the plane of the sky. Methods: We present the results of seven sources observed with the Jansky Very Large Array (JVLA) that were identified as water fountain candidates in an Effelsberg 100 m telescope survey of 74 AGB and early post-AGB stars. Results: We find that our sample of water fountain candidates displays strong variability in their 22 GHz H2O maser spectra. The JVLA observations show an extended bipolar H2O maser outflow for one source, the OH/IR star IRAS 18455+0448. This source was previously classified as a dying OH/IR star based on the exponential decrease of its 1612 MHz OH maser and the lack of H2O masers. We therefore also re-observed the 1612, 1665, and 1667 MHz OH masers. We confirm that the 1612 MHz masers have not reappeared and find that the1665/1667 MHz masers have decreased in strength by several orders of magnitude during the last decade. The JVLA observations also reveal a striking asymmetry in the red-shifted maser emission of IRAS 19422+3506. Conclusions: The OH/IR star IRAS 18455+0448 is confirmed to be a new addition to the

  12. The Application of LT-Table in TRIZ Contradiction Resolving Process

    NASA Astrophysics Data System (ADS)

    Wei, Zihui; Li, Qinghai; Wang, Donglin; Tian, Yumei

    TRIZ is used to resolve invention problems. ARIZ is the most powerful systematic method which integrates all of TRIZ heuristics. Definition of ideal final result (IFR), identification of contradictions and resource utilization are main lines of ARIZ. But resource searching of ARIZ has fault of blindness. Alexandr sets up mathematical model of transformation of the hereditary information in an invention problem using the theory of catastrophes, and provides method of resource searching using LT-table. The application of LT-table on contradiction resolving is introduced. Resource utilization using LT-table is joined into ARIZ step as an addition of TRIZ, apply this method in separator paper punching machine design.

  13. Volcanic jets, plumes, and collapsing fountains: evidence from large-scale experiments, with particular emphasis on the entrainment rate

    NASA Astrophysics Data System (ADS)

    Dellino, P.; Dioguardi, F.; Mele, D.; D'Addabbo, M.; Zimanowski, B.; Büttner, R.; Doronzo, D. M.; Sonder, I.; Sulpizio, R.; Dürig, T.; La Volpe, L.

    2014-06-01

    The source conditions of volcanic plumes and collapsing fountains are investigated by means of large-scale experiments. In the experiments, gas-particle jets issuing from a cylindrical conduit are forced into the atmosphere at different mass flow rates. Dense jets (high particle volumetric concentration, e.g., C 0 > 0.01) generate collapsing fountains, whose height scales with the squared exit velocity. This is consistent with Bernoulli's equation, which is a good approximation if air entrainment is negligible. In this case, kinetic energy is transformed into potential energy without any significant loss by friction with the atmosphere. The dense collapsing fountain, on hitting the ground, generates an intense shear flow similar to a pyroclastic density current. Dilute hot jets (low particle volumetric concentration, e.g., C 0 < 0.01) dissipate their initial kinetic energy at much smaller heights than those predicted by Bernoulli's equation. This is an indication that part of the total mechanical energy is lost by friction with the atmosphere. Significant air entrainment results in this case, leading to the formation of a buoyant column (plume) from which particles settle similarly to pyroclastic fallout. The direct measurement of entrainment coefficient in the experiments suggests that dense collapsing fountains form only when air entrainment is not significant. This is a consequence of the large density difference between the jet and the atmosphere. Cold dilute experiments result in an entrainment coefficient of about 0.06, which is typical of pure jets of fluid dynamics. Hot dilute experiments result in an entrainment coefficient of about 0.11, which is typical of thermally buoyant plumes. The entrainment coefficients obtained by experiments were used as input data in numerical simulations of fountains and plumes. A numerical model was used to solve the classic top-hat system of governing equations, which averages the field variables (e.g., column velocity and

  14. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT LASER TOUCH AND TECHNOLOGIES, LLC LASER TOUCH MODEL LT-B512

    EPA Science Inventory

    The Environmental Technology Verification report discusses the technology and performance of Laser Touch model LT-B512 targeting device manufactured by Laser Touch and Technologies, LLC, for manual spray painting operations. The relative transfer efficiency (TE) improved an avera...

  15. LT and MLT Dependencies of Pc 4 Amplitudes at CPMN Conjugate Stations

    NASA Astrophysics Data System (ADS)

    OBANA, Y.; Yoshikawa, A.; Morris, R. J.; Fraser, B. J.; Olson, J. V.; Solovyev, S. I.; Yumoto, K.

    2001-12-01

    Amplitude of magnetic pulsations observed on the ground can be expressed by B=A F(MLT) f(LT) σ where A is amplitude of source wave, F(MLT) shows MLT dependence of amplitude, f(LT) is a function of ionospheric conductivities at local time of station, and σ is a geological factor at station. In order to clarify F(MLT) and f(LT) of Pc 4 pulsations observed at the Circum-pan Pacific Magnetometer Network (CPMN) conjugate stations, we analyzed the CPMN magnetic data at Chokurdakh (CHD; M.lat.=64.67 deg.,M.lon.=212.12 deg., L=5.46), Kotzebue (KOT; 64.52, 249.72, 5.40), and Macquarie Isl. (MCQ; -64.50, 247.84, 5.40) during the interval of 15 - 17 September, 1994. Contaminated information of F(MLT) and f(LT) can be distributed by estimate the power ratio of CHD-KOT and CHD-MCQ. If we use the magnetic stations in the one-hemisphere, it is difficult to separate F(MLT) and f(LT). However, if we can analyzed data from the magnetic conjugate stations, the f(LT) can be extracted from the observed data, because F(MLT) at the conjugate points must be almost the same. From the analysis, the following results are obtained. (1) The F(MLT) of Pc 4 shows maximum in the prenoon sector and minimum in the afternoon sector. The maximum power is more than 3 times stronger than the minimum power. (2) The f(LT) of Pc 4 has the maximum around 6 and 18 LT, and minimum around 12 LT. The maximum power is 1.59 times stronger than the minimum power. In the present paper, we will compare the F(MLT) of Pc 4 on the ground and in space, and also discuss the LT dependence of obtained f(LT) on the ground.

  16. A novel formulation of L-thyroxine (L-T4) reduces the problem of L-T4 malabsorption by coffee observed with traditional tablet formulations.

    PubMed

    Vita, Roberto; Saraceno, Giovanna; Trimarchi, Francesco; Benvenga, Salvatore

    2013-02-01

    The purpose of this work is to evaluate if the coffee-associated malabsorption of tablet levothyroxine (L-T4) is reduced by soft gel capsule. We recruited 8 patients with coffee-associated L-T4 malabsorption including one hypothyroid patient. For 6 months, the patients were switched to the capsule maintaining the L-T4 daily dose. Patients took the capsule with water, having coffee 1 h later (proper habit, PH) on days 1-90, or with coffee ≤ 5 min later (improper habit, IH) on days 91-180. After 6 months, 2 patients volunteered for an acute loading test of 600 μg L-T4 (capsule) ingested with water (PH) or with coffee (IH). In the single hypothyroid patient, the post-switch TSH ranged 0.06-0.16 mU/L (PH) versus 5.8-22.4 mU/L pre-switch (PH) and 0.025-0.29 mU/L (IH) versus 26-34 mU/L pre-switch (IH). In the other 7 patients, post-switch TSH was 0.41 ± 0.46 (PH) versus 0.28 ± 0.20 pre-switch (PH) (P = 0.61) and 0.34 ± 0.30 (IH) versus 1.23 ± 1.47 pre-switch (IH) (P < 0.001). Importantly, TSH levels in PH versus IH habit did not differ post-switch (P = 0.90), but they did pre-switch (P < 0.0001). The proportions of post-switch TSH levels <0.10 mU/L with PH (33.3 %) or with IH (33.3 %) were borderline significantly greater than the corresponding pre-switch levels with PH (10.3 %) (P = 0.088) or with IH (0 %) (P = 0.0096). In the two volunteers, the L-T4 loading test showed that coffee influenced L-T4 pharmacokinetics minimally. Soft gel capsules can be used in patients who are unable/unwilling to change their IH of taking L-T4. PMID:22932947

  17. Field Operations Program - U.S. Postal Service - Fountain Valley Electric Carrier Route Vehicle Testing

    SciTech Connect

    Francfort, J.E.

    2002-01-21

    The United States Postal Service (USPS) has ordered 500 light-duty electric carrier route vehicles (ECRV) mostly for their delivery carriers to use in several California locations. The 500 ECRVs have been defined as a demonstration fleet to support a decision of potentially ordering 5,500 additional ECRVs. Several different test methods are being used by the USPS to evaluate the 500-vehicle deployment. One of these test methods is the ECRV Customer Acceptance Test Program at Fountain Valley, California. Two newly manufactured ECRVs were delivered to the Fountain Valley Post Office and eighteen mail carriers primarily drove the ECRVs on ''park and loop'' mail delivery routes for a period of 2 days each. This ECRV testing consisted of 36 route tests, 18 tests per vehicle. The 18 mail carriers testing the ECRVs were surveyed for the opinions on the performance of the ECRVs. The U.S. Department of Energy, through its Field Operations Program, is supporting the USPS's ECRV testing activities both financially and with technical expertise. As part of this support, Field Operations Program personnel at the Idaho National Engineering and Environmental Laboratory have compiled this report based on the data generated by the USPS and its testing contractor (Ryerson, Master and Associates, Inc.) During the 36 route tests, the two test vehicles were driven a total of 474 miles, averaging 13 mile per test. The distance of the 36 route tests ranged from 4 to 34 miles. Both miles driven and State-of-Charge (SOC) data was collected for only 28 of the route tests. During these 28 tests, the ECRVs were driven a total of 447 miles. The SOC used during the 28 tests averaged a 41% decrease and the average distance driven was 16 miles. This suggests that a 16-mile route uses almost half of the ECRV's battery energy. The 18 carriers also rated 12 ECRV traits that included the physical design of the ECRVs as well as their performance. Based on a scale of 1 being the lowest and 5 being

  18. Field Operations Program - US Postal Service Fountain Valley Electric Carrier Route Vehicle Testing

    SciTech Connect

    Francfort, James Edward

    2002-01-01

    The United States Postal Service (USPS) has ordered 500 light-duty electric carrier route vehicles (ECRV) mostly for their delivery carriers to use in several California locations. The 500 ECRVs have been defined as a demonstration fleet to support a decision of potentially ordering 5,500 additional ECRVs. Several different test methods are being used by the USPS to evaluate the 500-vehicle deployment. One of these test methods is the ECRV Customer Acceptance Test Program at Fountain Valley, California. Two newly manufactured ECRVs were delivered to the Fountain Valey Post Office and eighteen mail carriers primarily drove the ECRVs on "park and loop" mail delivery routes for a period of 2 days each. This ECRV testing consisted of 36 route tests, 18 tests per vehicle. The 18 mail carriers testing the ECRVs were surveyed for the opinions on the performance of the ECRVs. The U.S. Department of Energy, through its Field Operations Program, is supporting the USPS's ECRV testing activities both financially and with technical expertise. As part of this support, Field Operations Program personnel at the Idaho National Engineering and Environmental Laboratory have compiled this report based on the data generated by the USPS and its testing contractor (Ryerson, Master and Associates, Inc.) During the 36 route tests, the two test vehicles were driven a total of 474 miles, averaging 13 mile per test. The distance of the 36 route tests ranged from 4 to 34 miles. Both miles driven and State-of-Charge (SOC) data was collected for only 28 of the route tests. During these 28 tests, the ECRVs were driven a total of 447 miles. The SOC used during the 28 tests averaged a 41% decrease and the average distance driven was 16 miles. This suggests that a 16-mile route uses almost half of the ECRV's battery energy. The 18 carriers also rated 12 ECRV traits that included the physical design of the ECRVs as well as their performance. Based on a scale of 1 being the lowest and 5 being highest

  19. Periglacial Features in the Paleoequatorial Fountain Formation (Permo-Pennsylvanian), Colorado?

    NASA Astrophysics Data System (ADS)

    Sweet, D. E.; Soreghan, G. S.

    2005-12-01

    The Fountain Formation, along the east flank of the Front Range, Colorado, comprises coarse clastics shed as an alluvial wedge off the Ancestral Front range during the Ancestral Rocky Mountains orogeny. Locally, bedding-plane exposures within the Fountain exhibit a distinct geometric pattern composed of white, erosionally resistant ridges 2-10 cm wide and 13-61 cm deep rimming red polygons 15-76 cm across with depth-to-width ratios averaging 5.80. Both the white and the red lithologies comprise very poorly sorted, coarse arkose. However, in thin section, the white lithology exhibits a silicified micro-brecciated texture whereas the red lithology exhibits a diamictite texture with clasts suspended in a muddy matrix comprising ~25% of the rock. FTIR analysis of the <62 micron fraction (matrix) indicates that, relative to one another, the white lithology contains more quartz, whereas the red lithology contains more clay minerals. In addition to the polygons, downwardly tapering, clastic wedges occur locally. The wedges are 10-32 cm in width, penetrate to depths of 41- >220 cm, and have depth-to-width ratios averaging 4.31. Most wedges taper to a single terminus, but some splay downward. Granular to coarse arkosic sandstone fills wedges and locally exhibits a faint vertical foliation; laminae within host strata commonly bend upward adjacent to wedge edges. These preliminary data are most consistent with the hypothesis that both features relate to thermal contraction wherein the polygonal features represent fossil patterned ground and the clastic wedges record ice-wedge or seasonal frost crack casts. The color contrast is a diagenetic enhancement, the result of bleaching of the original polygonal surface by reducing fluids channeled by permeability contrasts between the muddy arkose (red) and the granule fills (now white). Contractional polygonal fractures have been related to (1) desiccation in an arid environment with either mud or evaporites providing cohesion and (2

  20. Quantum Dynamics in Atomic-Fountain Experiments for Measuring the Electric Dipole Moment of the Electron with Improved Sensitivity

    NASA Astrophysics Data System (ADS)

    Wundt, B. J.; Munger, C. T.; Jentschura, U. D.

    2012-10-01

    An improved measurement of the electron electric dipole moment (EDM) appears feasible using ground-state alkali atoms in an atomic fountain in which a strong electric field, which couples to a conceivable EDM, is applied perpendicular to the fountain axis. In a practical fountain, the ratio of the atomic tensor Stark shift to the Zeeman shift is a factor μ˜100. We expand the complete time-evolution operator in inverse powers of this ratio; complete results are presented for atoms of total spin F=3, 4, and 5. For a specific set of entangled hyperfine sublevels (coherent states), potential systematic errors enter only as even powers of 1/μ, making the expansion rapidly convergent. The remaining EDM-mimicking effects are further suppressed in a proposed double-differential setup, where the final state is interrogated in a differential laser configuration, and the direction of the strong electric field also is inverted. Estimates of the signal available at existing accelerator facilities indicate that the proposed apparatus offers the potential for a drastic improvement in EDM limits over existing measurements, and for constraining the parameter space of supersymmetric (SUSY) extensions of the Standard Model.

  1. RADIATION-DRIVEN FOUNTAIN AND ORIGIN OF TORUS AROUND ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Wada, Keiichi

    2012-10-10

    We propose a plausible mechanism to explain the formation of the so-called obscuring tori around active galactic nuclei (AGNs) based on three-dimensional hydrodynamic simulations including radiative feedback from the central source. The X-ray heating and radiation pressure on the gas are explicitly calculated using a ray-tracing method. This radiation feedback drives a 'fountain', that is, a vertical circulation of gas in the central few to tens parsecs. Interaction between the non-steady outflows and inflows causes the formation of a geometrically thick torus with internal turbulent motion. As a result, the AGN is obscured for a wide range of solid angles. In a quasi-steady state, the opening angles for the column density toward a black hole <10{sup 23} cm{sup -2} are approximately {+-}30 Degree-Sign and {+-}50 Degree-Sign for AGNs with 10% and 1% Eddington luminosity, respectively. Mass inflows through the torus coexist with the outflow and internal turbulent motion, and the average mass accretion rate to the central parsec region is 2 Multiplication-Sign 10{sup -4} {approx} 10{sup -3} M{sub Sun} yr{sup -1}; this is about 10 times smaller than accretion rate required to maintain the AGN luminosity. This implies that relatively luminous AGN activity is intrinsically intermittent or that there are other mechanisms, such as stellar energy feedback, that enhance the mass accretion to the center.

  2. Lonely drinking fountains and comforting coolers: paradoxes of water value and ironies of water use.

    PubMed

    Kaplan, Martha

    2011-01-01

    This article focuses ethnographically on Americans and technologies of drinking water, as tokens of and vehicles for health, agency, and surprising kinds of community. Journalists and water scholars have argued that bottled water is a material concomitant of privatization and alienation in U.S. society. But, engaging Latour, this research shows that water technologies and the groups they assemble, are plural. Attention to everyday entwining of workplace lives with drinking fountains, single-serve bottles, and spring water coolers shows us several different quests, some individualized, some alienated, but some seeking health via public, collective care, acknowledgment of stakeholding, and community organizing. Focused on water practices on a college campus, in the roaring 1990s and increasingly sober 2000s in the context of earlier U.S. water histories of inclusion and exclusion, I draw on ethnographic research from the two years that led up to the recession and the presidential election of 2008. I argue for understanding of water value through attention to water use, focusing both on the social construction of water and the use of water for social construction. PMID:22171409

  3. The Fountain of Health: Bringing Seniors’ Mental Health Promotion into Clinical Practice

    PubMed Central

    Thoo, Vanessa; Freer, Janya; Cassidy, Keri-Leigh

    2015-01-01

    Background The Fountain of Health (FoH) initiative offers valuable evidence-based mental health knowledge and provides clinicians with evaluated tools for translating knowledge into practice, in order to reduce seniors’ risks of mental disorders, including dementia. Methods A presentation on mental health promotion and educational materials were disseminated to mental health clinicians including physicians and other allied health professionals either in-person or via tele-education through a provincial seniors’ mental health network. Measures included: 1) a tele-education quality evaluation form, 2) a knowledge transfer questionnaire, 3) a knowledge translation-to-practice evaluation tool, and 4) a quality assurance questionnaire. Results A total of 74 mental health clinicians received the FoH education session. There was a highly significant (p < .0001) difference in clinicians’ knowledge transfer questionnaire scores pre- and post-educational session. At a two-month follow-up, 19 (25.7%) participants completed a quality assurance questionnaire, with all 19 (100%) of respondents stating they would positively recommend the FoH information to colleagues and patients. Eleven (20.4%) translation-to-practice forms were also collected at this interval, tracking clinician use of the educational materials. Conclusions The use of a formalized network for knowledge transfer allows for education and evaluation of health-care practitioners in both acquisition of practical knowledge and subsequent clinical behavior change. PMID:26740830

  4. Improved tests of local position invariance using 87Rb and 133Cs fountains.

    PubMed

    Guéna, J; Abgrall, M; Rovera, D; Rosenbusch, P; Tobar, M E; Laurent, Ph; Clairon, A; Bize, S

    2012-08-24

    We report tests of local position invariance based on measurements of the ratio of the ground state hyperfine frequencies of 133Cs and 87Rb in laser-cooled atomic fountain clocks. Measurements extending over 14 years set a stringent limit to a possible variation with time of this ratio: d ln(ν(Rb)/ν(Cs))/dt=(-1.39±0.91)×10(-16) yr(-1). This improves by a factor of 7.7 over our previous report [H. Marion et al., Phys. Rev. Lett. 90, 150801 (2003)]. Our measurements also set the first limit to a fractional variation of the Rb/Cs frequency ratio with gravitational potential at the level of c(2)d ln(ν(Rb)/ν(Cs))/dU=(0.11±1.04)×10(-6), providing a new stringent differential redshift test. The above limits equivalently apply to the fractional variation of the quantity α(-0.49)(g(Rb)/g(Cs)), which involves the fine-structure constant α and the ratio of the nuclear g-factors of the two alkalis. The link with variations of the light quark mass is also presented together with a global analysis combining other available highly accurate clock comparisons. PMID:23002732

  5. Herschel/HIFI CO, ^{13}CO and H_2O thermal emission in Water Fountain stars

    NASA Astrophysics Data System (ADS)

    García-García, E.; Rizzo, J. R.; Gómez, J. F.

    2015-05-01

    Water fountain stars are low- and intermediate-mass (0.8-8 M_⊙) evolved object whose water maser emission trace high velocity (>100 km s^{-1}) bipolar jets. They can be found in late AGB phase up to young PNe, although most of them are in the post-AGB phase. These stars may be key objects to understand how planetary nebulae are shaped. Besides the jets, WFs are expected to be surrounded by a large envelope expelled during the AGB and, in some cases, by a circumstellar toroid. We present a study of thermal lines (mid and high-J CO and ^{13}CO, and the lowest transitions of H_2O) from 8 WFs with the Herschel Space Observatory, in order to characterise their circumstellar material. The detected lines have been analysed with LTE and LVG models, to obtain the parameters of their circumstellar envelops. Our results also suggest the presence of thermal emission associated with the outflows. Isotope ratios of CO are compared with those in other post-AGB stars.

  6. Atomic fountain of laser-cooled Yb atoms for precision measurements

    SciTech Connect

    Pandey, Kanhaiya; Rathod, K. D.; Singh, Alok K.; Natarajan, Vasant

    2010-10-15

    We demonstrate launching of laser-cooled Yb atoms in a cold atomic fountain. Atoms in a collimated thermal beam are first cooled and captured in a magneto-optical trap (MOT) operating on the strongly allowed {sup 1}S{sub 0}{yields}{sup 1}P{sub 1} transition at 399 nm (blue line). They are then transferred to a MOT on the weakly allowed {sup 1}S{sub 0}{yields}{sup 3}P{sub 1} transition at 556 nm (green line). Cold atoms from the green MOT are launched against gravity at a velocity of around 2.5 m/s using a pair of green beams. We trap more than 10{sup 7} atoms in the blue MOT and transfer up to 70% into the green MOT. The temperature for the odd isotope {sup 171}Yb is {approx}1 mK in the blue MOT, and reduces by a factor of 40 in the green MOT.

  7. High Velocity Precessing Jet from the Water Fountain IRAS 18286-0959 Revealed by VLBA Observations

    NASA Astrophysics Data System (ADS)

    Yung, Bosco; Nakashima, J.; Imai, H.; Deguchi, S.; Diamond, P. J.; Kwok, S.

    2011-05-01

    We report the multi-epoch VLBA observations of 22.2GHz water maser emission associated with the "water fountain" star IRAS 18286-0959. The detected maser emission are distributed in the velocity range from -50km/s to 150km/s. The spatial distribution of over 70% of the identified maser features is found to be highly collimated along a spiral jet (namely, jet 1) extended from southeast to northwest direction, and the rest of the features appear to trace another spiral jet (jet 2) with a different orientation. The two jets form a "double-helix" pattern which lies across 200 milliarcseconds (mas). The maser features are reasonably fit by a model consisting of two precessing jets. The velocities of jet 1 and jet 2 are derived to be 138km/s and 99km/s, respectively. The precession period of jet 1 is about 56 years, and for jet 2 it is about 73 years. We propose that the appearance of two jets observed are the result of a single driving source with a significant proper motion. This research was supported by grants from the Research Grants Council of the Hong Kong Special Administrative Region, China, the Seed Funding Programme for Basic Research of the University of Hong Kong, Grant-in-Aid for Young Scientists from the Ministry 9 of Education, Culture, Sports, Science, and Technology, and Grant-in-Aid for Scientific Research from Japan Society for Promotion Science.

  8. UTC(OP) based on LNE-SYRTE atomic fountain primary frequency standards

    NASA Astrophysics Data System (ADS)

    Rovera, G. D.; Bize, S.; Chupin, B.; Guéna, J.; Laurent, Ph; Rosenbusch, P.; Uhrich, P.; Abgrall, M.

    2016-06-01

    UTC(OP), the French national realization of the international coordinated universal time, was redesigned and rebuilt. The first step was the implementation in October 2012 of a new algorithm based on a H-maser and on atomic fountain data. Thanks to the new implementation, the stability of UTC(OP) was dramatically improved and UTC(OP) competes with the best time scales available today. Then the hardware generation and distribution of the UTC(OP) physical signals were replaced. Part of the new hardware is composed of commercial devices, but the key elements were specifically developed. One of them is a special switch that allows the UTC(OP) signals to be derived from one of two time scales, based on two different H-masers, which are generated simultaneously. This insures the continuity of the UTC(OP) signal even when a change of the reference H-maser is required. With the new hardware implementation, UTC(OP) is made available through three coherent signals: 100 MHz, 10 MHz and 1 PPS. For more than 3 years, UTC(OP) remained well below 10 ns close to UTC, with a difference even less than 5 ns if we except a short period around MJD 56650.

  9. Polar Wind in the Context of the Auroral Plasma Fountain for 2 to 8 RE

    NASA Technical Reports Server (NTRS)

    Moore, T. E.; Giles, B. L.; Chandler, M. O.; Chappell, C. R.; Craven, P. D.; Su, Y.-J.; Horwitz, J. L.; Pollock, C. J.

    1997-01-01

    Operations of the POLAR Plasma Source Instrument have provided adequate observing time with controlled spacecraft potential to begin a 3D characterization of the polar wind as it exists in the context of the auroral plasma fountain. The principal periods of such polar wind observation to date have been 15-18 Apr. 96, 28 may 96, 14 Jun. - 6 Sep. 96, 17-29 Mar. 97, 29 May - 12 Jun. 97, 13-27 Aug. 97. Separate observations have been made near 2 RE geocentric in the south polar perigee passes and between 6-8 RE geocentric in the north polar apogee passes. Analyses of data from the Thermal Ion Dynamics Experiment during these periods are used to characterize the altitude, local time, and invariant latitude distribution of the polar wind. Data from these and other periods are used to establish the auroral plasma heating context within which the polar wind outflows exist. The available data will be used to address the temporal variability of the polar wind during the period of operations to date. Comparisons between the observations and a coupled fluid-semikinetic model are used to interpret the observed spatial structure and temporal variability.

  10. Galactic fountains and outflows in star forming dwarf galaxies: ISM expulsion and chemical enrichment

    NASA Astrophysics Data System (ADS)

    Melioli, Claudio

    2015-08-01

    We investigated the impact of supernova feedback in gas-rich dwarf galaxies experiencing a low-to-moderate star formation rate, typical of relatively quiescent phases between starbursts. We calculated the long term evolution of the ISM and the metal-rich SN ejecta using 3D hydrodynamical simulations, in which the feedback energy is deposited by SNII exploding in distinct OB associations. We found that a circulation flow similar to galactic fountains is generally estabilished, with some ISM lifted at heights of one to few kpc above the galactic plane. This gas forms an extra-planar layer, which falls back to the plane in about 108 yr, once the star formation stops. Very little or no ISM is expelled outside the galaxy system for the considered SFRs, even though in the most powerful model the SN energy is comparable to the gas binding energy. The metal-rich SN ejecta is instead more vulnerable to the feedback and we found that a significant fraction (25-80%) is vented in the intergalactic medium, even for low SN rate. About half of the metals retained by the galaxy are located far (z > 500 pc) from the galactic plane. Moreover, our models indicate that the circulation of the metal-rich gas out from and back to the galactic disk is not able to erase the chemical gradients imprinted by the (centrally concentrated) SN explosions.

  11. L-T4 bioequivalence and hormone replacement studies via feedback control simulations.

    PubMed

    Eisenberg, Marisa; Samuels, Mary; DiStefano, Joseph J

    2006-12-01

    FDA Guidance for testing bioequivalence of levothyroxine (L-T(4)) preparations has been challenged by several groups, based on multiple issues. The efficacy of single versus combined hormone therapy also is receiving additional scrutiny. To examine these concerns, we developed a new nonlinear feedback system simulation model of whole-body regulation mechanisms involving dynamics of T(3), T(4), TSH, plasma protein binding, extravascular regulatory enzyme systems, and the hypothalamic-pituitary-thyroid axis, all quantified from human data. To address bioequivalence, we explored how to best account for varying and unmeasured endogenous T(4) following dosing with exogenous oral L-T(4) in euthyroid volunteers in required pharmacokinetic (PK) studies, by simulating various dosing scenarios and developing a new and simple correction method. We computed and assessed dosing error effects and baseline corrections using simulator-predicted endogenous T(4) level variations, due to actual closed-loop effects, and compared these with approximate corrections computed directly from PK data. Predicted dose-responses were quite linear, and for constant baseline, 7-day half-life, and our new formula-correction methods, we established some bounds on bioequivalent dosages. Simulated replacement after thyroidectomy required 141 microg L-T(4) only to normalize T(3) tissue levels and 162 microg L-T(4) to normalize plasma T(3) levels. A combined dose of approximately 103 microg L-T(4) plus approximately 6 microg T(3) ( approximately 18:1 ratio) was needed to normalize both plasma T(3) and T(4) and average tissue T(3) levels. However, simulated average tissue T(3) levels were normalized with standard L-T(4)-only therapy, and plasma T(3) levels were still within the normal range. We suggest a simple and more accurate correction for endogenous T(4) in PK studies. Current standard L-T(4)-only treatment is supported for routine replacement needs. PMID:17199439

  12. CysLT1R Antagonists Inhibit Tumor Growth in a Xenograft Model of Colon Cancer

    PubMed Central

    Savari, Sayeh; Liu, Minghui; Zhang, Yuan; Sime, Wondossen; Sjölander, Anita

    2013-01-01

    The expression of the inflammatory G-protein coupled receptor CysLT1R has been shown to be upregulated in colon cancer patients and associated with poor prognosis. The present study investigated the correlation between CysLT1R and colon cancer development in vivo using CysLT1R antagonists (ZM198,615 or Montelukast) and the nude mouse xenograft model. Two drug administration regimens were established. The first regimen was established to investigate the importance of CysLT1R in tumor initiation. Nude mice were inoculated with 50 µM CysLT1R antagonist-pretreated HCT-116 colon cancer cells and received continued treatment (5 mg/kg/day, intraperitoneally). The second regimen aimed to address the role of CysLT1R in tumor progression. Nude mice were inoculated with non-pretreated HCT-116 cells and did not receive CysLT1R antagonist treatment until recordable tumor appearance. Both regimens resulted in significantly reduced tumor size, attributed to changes in proliferation and apoptosis as determined by reduced Ki-67 levels and increased levels of p21WAF/Cip1 (P<0.01), cleaved caspase 3, and the caspase-cleaved product of cytokeratin 18. Decreased levels of VEGF (P<0.01) and reduced vessel size (P<0.05) were also observed, the latter only in the ZM198,615-pretreatment group. Furthermore, we performed a series of in vitro studies using the colon cancer cell line HCT-116 and CysLT1R antagonists. In addition to significant reductions in cell proliferation, adhesion and colony formation, we observed induction of cell cycle arrest and apoptosis in a dose-dependent manner. The ability of Montelukast to inhibit growth of human colon cancer xenograft was further validated by using two additional colon cancer cell lines, SW-480 and HT-29. Our results demonstrate that CysLT1R antagonists inhibit growth of colon cancer xenografts primarily by reducing proliferation and inducing apoptosis of the tumor cells. PMID:24039952

  13. Comparative analysis of SV40 17kT and LT function in vivo demonstrates that LT's C-terminus re-programs hepatic gene expression and is necessary for tumorigenesis in the liver

    PubMed Central

    Comerford, S A; Schultz, N; Hinnant, E A; Klapproth, S; Hammer, R E

    2012-01-01

    Transformation by Simian Virus 40 (SV40) large T antigen (LT) is mediated in large part by its interaction with a variety of cellular proteins at distinct binding domains within LT. While the interaction of LT's N-terminus with the tumor suppressor Rb is absolutely required for LT-dependent transformation, the requirement for the interaction of LT's C-terminus with p53 is less clear and cell- and context-dependent. Here, we report a line of transgenic mice expressing a doxycycline-inducible liver-specific viral transcript that produces abundant 17kT, a naturally occurring SV40 early product that is co-linear with LT for the first 131 amino acids and that binds to Rb, but not p53. Comparative analysis of livers of transgenic mice expressing either 17kT or full length LT demonstrates that 17kT stimulates cell proliferation and induces hepatic hyperplasia but is incapable of inducing hepatic dysplasia or promoting hepatocarcinogenesis. Gene expression profiling demonstrates that 17kT and LT invoke a set of shared molecular signatures consistent with the action of LT's N-terminus on Rb-E2F-mediated control of hepatocyte transcription. However, 17kT also induces a unique set of genes, many of which are known transcriptional targets of p53, while LT actively suppresses them. LT also uniquely deregulates the expression of a subset of genes within the imprinted network and rapidly re-programs hepatocyte gene expression to a more fetal-like state. Finally, we provide evidence that the LT/p53 complex provides a gain-of-function for LT-dependent transformation in the liver, and confirm the absolute requirement for LT's C-terminus for liver tumor development by demonstrating that phosphatase and tensin homolog (PTEN)-deficiency readily cooperates with LT, but not 17kT, for tumorigenesis. These results confirm independent and inter-dependent functions for LT's N- and C-terminus and emphasize differences in the requirements for LT's C-terminus in cell-type dependent

  14. Polarized structure function sigma_lt' for kaon electroproduction in the nucleon resonance region

    SciTech Connect

    Rakhsha Nasseripour; B. Raue; Daniel Carman; Pawel Ambrozewicz

    2008-02-19

    The first measurements of the polarized structure function $\\sigma_{LT'}$ for the reaction $p(\\vec e,e'K^+)\\Lambda$ in the nucleon resonance region are reported. Measurements are included from threshold up to $W$=2.05~GeV for central values of $Q^2$ of 0.65 and 1.00~GeV$^2$, and nearly the entire kaon center-of-mass angular range. $\\sigma_{LT'}$ is the imaginary part of the longitudinal-transverse response and is expected to be sensitive to interferences between competing intermediate $s$-channel resonances, as well as resonant and non-resonant processes. The results for $\\sigma_{LT'}$ are comparable in magnitude to previously reported results from CLAS for $\\sigma_{LT}$, the real part of the same response. An intriguing sign change in $\\sigma_{LT'}$ is observed in the high $Q^2$ data at $W\\approx 1.9$~GeV. Comparisons to several existing model predictions are shown.

  15. Evaluation of fecal contamination by human and ruminant sources in upper Fountain Creek, Colorado, 2007-2008, by using multiple lines of evidence:

    USGS Publications Warehouse

    Stoeckel, Donald

    2011-01-01

    Fountain Creek is a high-gradient stream on the Front Range of the Rocky Mountains in Colorado. The headwaters of Fountain Creek drain Pikes Peak, a major destination for tourism. Fountain Creek is a drinking-water source for the City of Colorado Springs, Colorado, and is used for irrigation, recreation, and other purposes between Colorado Springs and the confluence with the Arkansas River at Pueblo, Colorado. In 2008, Fountain Creek was placed on the Colorado 303(d) list of impaired streams because of fecal contamination. Colorado uses a 30-day geometric mean standard of 126 Escherichia coli per 100 milliliters as its management goal for recreational waters. The objective of this study was to identify major sources of Escherichia coli in upper Fountain Creek during exceedances of the State recreational water standard. To meet this objective, a new approach was developed and tested that uses genetic marker analysis for microbial source tracking, along with other information, to evaluate potential contributions of fecal contamination from various sources.

  16. Coupled textural and compositional characterization of basaltic scoria: Insights into the transition from Strombolian to fire fountain activity at Mount Etna, Italy

    NASA Astrophysics Data System (ADS)

    Polacci, Margherita; Corsaro, Rosa Anna; Andronico, Daniele

    2006-03-01

    Strombolian and fire fountain activities represent a common expression of explosive basaltic eruptions. However, the transition between these two eruptive styles and their source mechanisms are still debated. We use textural and compositional studies to characterize pyroclastic material from both the Strombolian and Hawaiian-style fire fountain phases of the January June 2000 Etna activity. We find that basaltic scoria presents distinctive textural and compositional features that reflect different modes of magma vesiculation and crystallization in the two eruptive regimes. Overall, magma that forms Strombolian scoria is far more crystallized, less vesicular, and more evolved, indicating strong volatile depletion and longer residence time before being erupted. Fire fountain scoria indicates a fast-rising magma with evidence of moderate syneruptive volatile exsolution. The new textural and compositional data set is integrated with previous volcanological and geophysical investigations to provide further insights into the dynamics of fire fountains, and to frame the transition from Strombolian explosions to fire fountain activity into a model that may apply to future eruptions at Mount Etna as well as other active basaltic volcanoes.

  17. Broadening and shifting of Bragg reflections of nanoscale-microtwinned LT-Ni3Sn2

    NASA Astrophysics Data System (ADS)

    Leineweber, Andreas; Krumeich, Frank

    2013-12-01

    The effect of nanoscale microtwinning of long-range ordered domains in LT-Ni3Sn2 on its diffraction behaviour was studied by X-ray powder diffraction and electron microscopy. LT-Ni3Sn2 exhibits a Ni2In/NiAs-type structure with a superstructure breaking the symmetry relative to the hexagonal high-temperature (HT) to the orthorhombic low-temperature (LT) phase, implying three different twin-domain orientations. The microstructure was generated by annealing HT-Ni3Sn2 considerably below the order-disorder transition temperature, establishing the LT phase avoiding too much domain coarsening. High-resolution electron microscopy reveals domain sizes of 100-200 Å compatible with the Scherrer broadening of the superstructure reflections recorded by X-ray diffraction. Whereas the orthorhombic symmetry of the LT phase leads in powder-diffraction patterns from coarse-domain size material to splitting of the fundamental reflections, this splitting does not occur for the LT-Ni3Sn2 with nanoscale domains. Instead, a (pseudo)hexagonal indexing is possible giving hexagonal lattice parameters, which are, however, incompatible with the positions of the superstructure reflections. This can be attributed to interference between X-rays scattered by the differently oriented, truly orthorhombic domains leading to merging of the fundamental reflections. These show pronounced anisotropic microstrain-like broadening, where the integral breadths ? on the reciprocal d-spacing scale of a series of higher order reflection increase in a non-linear fashion with upward curvature with the reciprocal d-spacings ? of these reflections. Such a type of unusual microstrain broadening appears to be typical for microstructures which are inhomogeneous on the nanoscale, and in which the structural inhomogeneities lead to small phase shifts of the scattered radiation from different locations (e.g. domains).

  18. VLA Monitoring of the Water Masers in the Water Fountain Nebula IRAS16342-3814

    NASA Astrophysics Data System (ADS)

    Fagrelius, Eric; Claussen, M.; Sahai, R.; Morris, M.

    2010-01-01

    This study of water maser emission from the "water fountain" pre-planetary nebula IRAS16342-3814 used 1.35 cm observations made with the Very Large Array of the National Radio Astronomy Observatory. Seven observing epochs over one year sampled an LSR velocity range of 370 km/sec (since masers are known over a range of more than 250 km/s). The wide range reveals maser spots at several different velocities, including the well-known features at extreme red-shifted ( LSR +180 km/sec) and blue-shifted ( LSR -66 km/sec) velocities, relative to the stellar velocity. Identification of maser spots over time gives a better picture of the growth, orientation, and physical nature of the bipolar outflow lobes. The data reveals maser spots at previously unreported velocities ( LSR -10 to +5 km/s). Some maser spots identified in the past are no longer seen. Masers from different velocity ranges differ in intensity by 100x. Within the year, some individual masers vary in intensity by 10x. Besides revealing growth and decline of the different masers, we hoped to observe the separation of the extremely shifted masers. Previous studies measured about 3 arcsec in breadth. The angular resolution of the VLA images was typically 0.7 - 1.2 arcseconds, and the data were imaged with 0.2 arcsec per pixel, so we expected to resolve the separation of extremely shifted masers by 15 pixels. This separation was not observed. Existing, near-simultaneous observations with the Very Large Baseline Array will be used to investigate this expected separation. This research was performed under the National Science Foundation's Research Experience for Teachers program during the summer of 2009. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. RS and MM were funded by a Long Term Space Astrophysics award from NASA for this work

  19. Lava discharge during Etna's January 2011 fire fountain tracked using MSG-SEVIRI

    NASA Astrophysics Data System (ADS)

    Gouhier, Mathieu; Harris, Andrew; Calvari, Sonia; Labazuy, Philippe; Guéhenneux, Yannick; Donnadieu, Franck; Valade, Sébastien

    2012-05-01

    Etna's January 2011 eruption provided an excellent opportunity to test the ability of Meteosat Second Generation satellite's Spinning Enhanced Visible and InfraRed Imager (SEVIRI) sensor to track a short-lived effusive event. The presence of lava fountaining, the rapid expansion of lava flows, and the complexity of the resulting flow field make such events difficult to track from the ground. During the Etna's January 2011 eruption, we were able to use thermal data collected by SEVIRI every 15 min to generate a time series of the syn-eruptive heat flux. Lava discharge waxed over a ~1-h period to reach a peak that was first masked from the satellite view by a cold tephra plume and then was of sufficient intensity to saturate the 3.9-μm channel. Both problems made it impossible to estimate time-averaged lava discharge rates using the syn-eruptive heat flux curve. Therefore, through integration of data obtained by ground-based Doppler radar and thermal cameras, as well as ancillary satellite data (from Moderate Resolution Imaging Spectrometer and Advanced Very High Resolution Radiometer), we developed a method that allowed us to identify the point at which effusion stagnated, to allow definition of a lava cooling curve. This allowed retrieval of a lava volume of ~1.2 × 106 m3, which, if emitted for 5 h, was erupted at a mean output rate of ~70 m3 s-1. The lava volume estimated using the cooling curve method is found to be similar to the values inferred from field measurements.

  20. A Search for L/T Transition Dwarfs with Pan-STARRS1 and WISE. II. L/T Transition Atmospheres and Young Discoveries

    NASA Astrophysics Data System (ADS)

    Best, William M. J.; Liu, Michael C.; Magnier, Eugene A.; Deacon, Niall R.; Aller, Kimberly M.; Redstone, Joshua; Burgett, W. S.; Chambers, K. C.; Draper, P.; Flewelling, H.; Hodapp, K. W.; Kaiser, N.; Metcalfe, N.; Tonry, J. L.; Wainscoat, R. J.; Waters, C.

    2015-12-01

    The evolution of brown dwarfs from L to T spectral types is one of the least understood aspects of the ultracool population, partly for lack of a large, well-defined, and well-characterized sample in the L/T transition. To improve the existing census, we have searched ≈28,000 deg2 using the Pan-STARRS1 and Wide-field Infrared Survey Explorer surveys for L/T transition dwarfs within 25 pc. We present 130 ultracool dwarf discoveries with estimated distances ≈9-130 pc, including 21 that were independently discovered by other authors and 3 that were previously identified as photometric candidates. Seventy-nine of our objects have near-IR spectral types of L6-T4.5, the most L/T transition dwarfs from any search to date, and we have increased the census of L9-T1.5 objects within 25 pc by over 50%. The color distribution of our discoveries provides further evidence for the “L/T gap,” a deficit of objects with (J - K)MKO ≈ 0.0-0.5 mag in the L/T transition, and thus reinforces the idea that the transition from cloudy to clear photospheres occurs rapidly. Among our discoveries are 31 candidate binaries based on their low-resolution spectral features. Two of these candidates are common proper motion companions to nearby main sequence stars; if confirmed as binaries, these would be rare benchmark systems with the potential to stringently test ultracool evolutionary models. Our search also serendipitously identified 23 late-M and L dwarfs with spectroscopic signs of low gravity implying youth, including 10 with vl-g or int-g gravity classifications and another 13 with indications of low gravity whose spectral types or modest spectral signal-to-noise ratio do not allow us to assign formal classifications. Finally, we identify 10 candidate members of nearby young moving groups (YMG) with spectral types L7-T4.5, including three showing spectroscopic signs of low gravity. If confirmed, any of these would be among the coolest known YMG members and would help to determine

  1. Lidar measurements carried out during the 28 February 2013 lava fountain event at Mt. Etna, in Italy

    NASA Astrophysics Data System (ADS)

    Scollo, Simona; Boselli, Antonella; Coltelli, Mauro; Leto, Giuseppe; Pisani, Gianluca; Spinelli, Nicola; Wang, Xuan; Zanmar Sanchez, Ricardo

    2015-04-01

    Mt. Etna, in Italy, is one of the most active volcanoes in the world. Since 2011, the New South East Crater produced lava fountains that formed eruption columns rising up to several kilometers above sea level and fine ash dispersed hundreds kilometers away from the central craters. One of these events occurred during the 28 February 2013. The volcanic plume was directed toward the E and reached, during the climax phase, an height greater than 9 km above sea level. Lidar measurements were performed immediately after the lava fountain activity by a new portable Raman scanning Lidar system that is operating in Catania since 2013. The Lidar is operated at the Serra La Nave station, only 7 km away far from the Etna summits, and, during the winter seasons, at the INAF-Astrophysical Observatory in Catania. The Lidar named AMPLE is a portable multiwavelength scanning lidar system with depolarization measurement capability, able to carry out high quality 3D map of particle optical and microphysical properties. The laser source is a doubled and tripled diode pumped Nd:YAG laser, with a repetition rate of 1KHz. The Lidar system detects the elastic Lidar returns at 355nm and the N2 Raman Lidar echoes at 386nm. Each signal is acquired with a raw spatial resolution varying from 30cm to 30m. Results of the measurements performed on 28 February 2013 show different layers: the first layer below 1.5 km corresponds to smaller not depolarizing particles of local origin while the layer up to 7 km, is related to volcanic ash coming from Etna. A discrimination between spherical and non-spherical particles in the volcanic plume is clear from the aerosol depolarization values in the atmospheric column interested by the volcanic plume. Some differences in the aerosol size and typology are also highlighted by the Lidar Ratio values. Lidar measurements presented here show new insights on the plume dynamics during Etna lava fountain events.

  2. Testing Local Position Invariance with Four Cesium-Fountain Primary Frequency Standards and Four NIST Hydrogen Masers

    SciTech Connect

    Ashby, N.; Heavner, T. P.; Jefferts, S. R.; Parker, T. E.; Radnaev, A. G.; Dudin, Y. O.

    2007-02-16

    We report the most sensitive tests to date of the assumption of local position invariance (LPI) underlying general relativity, based on a 7 yr comparison of cesium and hydrogen atomic clocks (frequency standards). The latest results place an upper limit that is over 20 times smaller than the previous most sensitive tests; this is consistent with the null shift predicted by LPI. The result is based on precise comparisons of frequencies of four hydrogen masers maintained by NIST, with four independent Cs fountain clocks--one at NIST and three in Europe--as the Sun's gravitational potential at Earth's surface varies due to Earth's orbital eccentricity.

  3. Superfund record of decision (EPA Region 4): Beaunit Circular Knit and Dyeing, Greenville County, Fountain Inn, SC, September 29, 1995

    SciTech Connect

    1996-03-01

    This decision document presents the selected remedial action for the Beaunit Circular Knit and Dying Superfund Site (the Site) in Fountain Inn, South Carolina. The major components of the selected remedy include: containment of soils and sediments contaminated with volatile organic compounds (VOCs) and metals by capping of the lagoon area; and additional monitoring of groundwater and soils on a regular schedule to determine effects of construction of lagoon cap, and to insure effectiveness of cap after construction. Modifications to the frequency or termination of continued monitoring will be determined during the Remedial Action and the Five Year Review.

  4. Clinical coding. Code breakers.

    PubMed

    Mathieson, Steve

    2005-02-24

    --The advent of payment by results has seen the role of the clinical coder pushed to the fore in England. --Examinations for a clinical coding qualification began in 1999. In 2004, approximately 200 people took the qualification. --Trusts are attracting people to the role by offering training from scratch or through modern apprenticeships. PMID:15768716

  5. LOW TEMPERATURE THERMAL TREATMENT (LT3®) TECHNOLOGY - ROY F. WESTON, INC. - APPLICATIONS ANALYSIS REPORT

    EPA Science Inventory

    This report evaluates the Low Temperature Thermal Treatment (LT3®) system's ability to remove VOC and SVOC compounds from solid wastes. This evaluation is based on treatment performance and cost data from the Superfund Innovative Technology (SITE) demonstration and fi...

  6. TSH-Based Protocol, Tablet Instability, and Absorption Effects on L-T4 Bioequivalence

    PubMed Central

    DiStefano, Joseph J.

    2009-01-01

    Background FDA Guidance for pharmacokinetic (PK) testing of levothyroxine (L-T4) for interbrand bioequivalence has evolved recently. Concerns remain about efficacy and safety of the current protocol, based on PK analysis following supraphysiological L-T4 dosing in euthyroid volunteers, and recent recalls due to intrabrand manufacturing problems also suggest need for further refinement. We examine these interrelated issues quantitatively, using simulated what-if scenarios testing efficacy of a TSH-based protocol and tablet stability and absorption, to enhance precision of L-T4 bioequivalence methods. Methods We use an updated simulation model of human thyroid hormone regulation quantified and validated from data that span a wide range of normal and abnormal thyroid system function. Bioequivalence: We explored a TSH-based protocol, using normal replacement dosing in simulated thyroidectomized patients, switching brands after 8 weeks of full replacement dosing. We simulated effects of tablet potency differences and intestinal absorption differences on predicted plasma TSH, T4, and triiodothyronine (T3) dynamics. Stability: We simulated effects of potency decay and lot-by-lot differences in realistic scenarios, using actual tablet potency data spanning 2 years, comparing the recently reduced 95–105% FDA-approved potency range with the original 90–110% range. Results A simulated decrease as small as 10–15% in L-T4 or its absorption generated TSH concentrations outside the bioequivalence target range (0.5–2.5 mU/L TSH), whereas T3 and T4 plasma levels were maintained normal. For a 25% reduction, steady-state TSH changed 300% (from 1.5 to 6 mU/L) compared with <25% for both T4 and T3 (both within their reference ranges). Stability: TSH, T4, and T3 remained within normal ranges for most potency decay scenarios, but tablets of the same dose strength and brand were not bioequivalent between lots and between fresh and near-expired tablets. Conclusions A

  7. Genetic Fusions of Heat-Labile Toxoid (LT) and Heat-Stable Toxin b (STb) of Porcine Enterotoxigenic Escherichia coli Elicit Protective Anti-LT and Anti-STb Antibodies ▿

    PubMed Central

    Zhang, Weiping; Francis, David H.

    2010-01-01

    Enterotoxigenic Escherichia coli (ETEC)-associated diarrhea causes a substantial economic loss to swine producers worldwide. The majority of ETEC strains causing porcine diarrhea, especially postweaning diarrhea (PWD), produce heat-labile toxin (LT) and heat-stable toxin b (STb). LT is commonly used in vaccine development, but STb has not been included because of its poor immunogenicity. As a virulence factor in porcine diarrhea, STb needs to be included as an antigen for development of broad-spectrum vaccines. In this study, we used an LT toxoid (LTR192G [hereafter, LT192]) derived from porcine ETEC to carry a mature STb peptide for LT192-STb fusions to enhance STb immunogenicity for potential vaccine application. Anti-LT and anti-STb antibodies were detected in immunized rabbits and pigs. In addition, when challenged with an STb-positive ETEC strain, all 10 suckling piglets borne by immunized gilts remained healthy, whereas 7 out 9 piglets borne by unimmunized gilts developed moderate diarrhea. This study indicates that the LT192-STb fusion enhanced anti-STb immunogenicity and suggests the LT192-STb fusion antigen can be used in future vaccine development against porcine ETEC diarrhea. PMID:20505006

  8. Galactic fountains and their connection with high and intermediate velocity clouds

    NASA Astrophysics Data System (ADS)

    Spitoni, E.; Recchi, S.; Matteucci, F.

    2008-06-01

    Context: Sequential supernova explosions create supershells which can break out a stratified medium, producing bipolar outflows. The gas of the supershells can fragment into clouds which eventually fall toward the disk producing so-called galactic fountains. Aims: The aim of this paper is to calculate the expansion law and chemical enrichment of a supershell powered by the energetic feedback of a typical Galactic OB association at various galactocentric radii. We study the orbits of the fragments created when the supershell breaks out and we compare their kinetic and chemical properties with the available observations of high - and intermediate - velocity clouds. Methods: We use the Kompaneets (1960, Soviet Phys. Dokl., 5, 46) approximation for the evolution of the superbubble driven by sequential supernova explosions and we compute the abundances of oxygen and iron residing in the thin cold supershell. We assume that supershells are fragmented by Rayleigh-Taylor instabilities and we follow the orbit of the clouds either ballistically or by means of a hybrid model considering viscous interaction between the clouds and the extra-planar gas. Results: Given the self-similarity of the solutions, clouds are always formed ~448 pc above the plane. If the initial metallicity is solar, the pollution from dying stars of the OB association has a negligible effect on the chemical composition of the clouds. The maximum height reached by the clouds above the plane seldom exceeds 2 kpc and when averaging over different throwing angles, the landing coordinate differs from the throwing coordinate by ~1 kpc at most. Conclusions: The range of heights and [O/Fe] ratios spanned by our clouds suggest that the high velocity clouds cannot have a Galactic origin, whereas intermediate velocity clouds have kinematic properties similar to our modeled clouds but have overabundances observed for the [O/Fe] ratios that can be reproduced only with initial metallicities that are too low compared

  9. Dayside observations of thermal-ion upwellings at 800-km altitude - An ionospheric signature of the cleft ion fountain

    NASA Technical Reports Server (NTRS)

    Tsunoda, R. T.; Livingston, R. C.; Vickrey, J. F.; Heelis, R. A.; Hanson, W. B.

    1989-01-01

    There is a growing body of evidence that energetic heavy ions observed at one or more earth radii over the polar cap originate from the dayside ionosphere in the vicinity of the dayside cleft. The ions, consisting mostly of O(+), are often characterized by conic pitch-angle distributions, suggesting that they have undergone acceleration transverse to geomagnetic field lines. This process of ion injection from a latitudinally localized source region in the dayside auroral oval followed by dispersal throughout the entire polar cap has been called the 'cleft ion fountain'. Here, results are presented of upward thermal-ion flows measured at 800-km altitude in the dayside polar ionosphere by the Hilat satellite. The characteristics of these thermal-ion upwellings (TIU) are described and shown to be closely associated with the cleft ion fountain. It is shown that TIU events are latitudinally confined and spatially collocated with cleft electron precipitation, upward field-aligned currents, and velocity gradients in magnetospheric convection.

  10. The structure of basaltic scoria and reticulite and inferences for vesiculation, foam formation, and fragmentation in lava fountains

    NASA Astrophysics Data System (ADS)

    Mangan, Margaret T.; Cashman, Katharine V.

    1996-09-01

    In this investigation pyroclast structures are used to constrain degassing in basaltic lava fountains. Vesicle size, shape, number density, interconnectedness and packing character are quantified and related to (1) the kinetics of bubble nucleation and growth, (2) the structural evolution of magmatic foams and (3) the influence of vesiculation rate on magma fragmentation. Measurements made on a diverse suite of pyroclasts from Kilauea volcano indicate that basaltic foams evolve through an initially disordered, closed-celled, spherical state to a well-ordered, open-celled, polyhedral state as the vesicularity rises from ~ 75 to 98%. The structural changes occur rapidly (< 10 s) in the conduit and fountain in response to an intense vesiculation burst. Vesicle size distribution systematics indicate bubble nucleation rates (~ 2 × 10 4 events cm -3s -1) that are approximately three orders of magnitude greater than those found for effusive eruptive activity. Bubble growth rates (~ 9 × 10 -4 cm/s) exceed effusive estimates by a factor of 3. The observed "runaway" rate of bubble production indicates strong supersaturations at the onset of nucleation. We speculate that the rise speed of the magma, as it reaches the level where significant volatile exsolution begins, determines the intensity of the vesiculation burst, and hence the vigor of the eruption. Rapid expansion and acceleration of the magma under these conditions may provide the impetus for fragmentation.

  11. Genetic Fusions of Heat-Labile (LT) and Heat-Stable (ST) Toxoids of Porcine Enterotoxigenic Escherichia coli Elicit Neutralizing Anti-LT and Anti-STa antibodies ▿

    PubMed Central

    Zhang, Weiping; Zhang, Chengxian; Francis, David H.; Fang, Ying; Knudsen, David; Nataro, James P.; Robertson, Donald C.

    2010-01-01

    Enterotoxigenic Escherichia coli (ETEC) strains are a major cause of diarrheal disease in humans and farm animals. E. coli fimbriae, or colonization factor antigens (CFAs), and enterotoxins, including heat-labile enterotoxins (LT) and heat-stable enterotoxins (ST), are the key virulence factors in ETEC diarrhea. Unlike fimbriae or LT, STa has not often been included as an antigen in development of vaccines against ETEC diarrhea because of its poor immunogenicity. STa becomes immunogenic only after being coupled with a strongly immunogenic carrier protein. However, native or shorter STa antigens either had to retain toxic activity in order to become antigenic or elicited anti-STa antibodies that were not sufficiently protective. In this study, we genetically mutated the porcine LT (pLT) gene for a pLT192(R→G) toxoid and the porcine STa (pSTa) gene for three full-length pSTa toxoids [STa11(N→K), STa12(P→F), and STa13(A→Q)] and used the full-length pLT192 as an adjuvant to carry the pSTa toxoid for pLT192:pSTa-toxoid fusion antigens. Rabbits immunized with pLT192:pSTa12 or pLT192:pSTa13 fusion protein developed high titers of anti-LT and anti-STa antibodies. Furthermore, rabbit antiserum and antifecal antibodies were able to neutralize purified cholera toxin (CT) and STa toxin. In addition, preliminary data suggested that suckling piglets born by a sow immunized with the pLT192:pSTa13 fusion antigen were protected when challenged with an STa-positive ETEC strain. This study demonstrated that pSTa toxoids are antigenic when fused with a pLT toxoid and that the elicited anti-LT and anti-STa antibodies were protective. This fusion strategy could provide instructive information to develop effective toxoid vaccines against ETEC-associated diarrhea in animals and humans. PMID:19858307

  12. Prevention of Ocular Scarring After Glaucoma Filtering Surgery Using the Monoclonal Antibody LT1009 (Sonepcizumab) in a Rabbit Model

    PubMed Central

    Lukowski, Zachary L.; Min, Jeff; Beattie, Ashley R.; Meyers, Craig A.; Levine, Monica A.; Stoller, Glenn; Schultz, Gregory S.; Samuelson, Don A.; Sherwood, Mark B.

    2013-01-01

    Purpose Excessive scarring leading to failure of the filtering bleb continues to be a major problem after glaucoma filtration surgery. This study examines the antifibrotic effects of the anti-S1P monoclonal antibody LT1009 (Sonepcizumab) in prolonging bleb survival in a rabbit model of glaucoma filtering surgery. Methods The frequency of LT1009 dosage was determined initially using an enzyme-linked immunosorbent assay assay measuring LT1009 eye tissue retention in 6 New Zealand White rabbits. A further 21 New Zealand White rabbits underwent glaucoma filtering surgery. Bleb tissues were observed and compared clinically and histologically. The duration of bleb elevation was compared among LT1009, balanced saline solution (BSS) negative control, and mitomycin-C (MMC)-positive control. Results The mean duration of bleb survival was 28.5 ± 8.5 days for rabbits receiving injections of LT1009, 21.0 ± 5.6 days for those receiving injections of BSS, and 33.8 ± 5.6 days for rabbits receiving MMC. Analysis of variance with post hoc testing suggests a statistically significant trend of improvement in bleb duration for LT1009 when compared with BSS controls. Non-painful, upper eyelid edema was noted after 5 injections of LT1009, which resolved over a 10-day period. MMC eyes developed avascular conjunctivas with areas of thinning and sparse cellularity, whereas the conjunctiva of LT1009 and BSS eyes remained relatively normal. Conclusions The monoclonal antibody LT1009 demonstrated a longer duration of bleb elevation than BSS control without adverse conjunctival effects associated with MMC. However, after multiple doses LT1009 use was associated with short-term upper eyelid edema. PMID:21946553

  13. Simultaneous oral immunization of mice with live attenuated Escherichia coli expressing LT192-STa 13 and LT 192-STb fusion immunogen, respectively, for polyvalent vaccine candidate.

    PubMed

    Liu, Wenxin; Li, Jinping; Bao, Jun; Li, Xingyue; Guan, Weikun; Yuan, Chaowen; Tang, Jie; Zhao, Zhiteng; Shi, Dongfang

    2015-05-01

    Previous epidemiological study showed that most of the porcine enterotoxin Escherichia coli (ETEC) strains harbor multiple enterotoxins but lack any of the fimbriae or non-fimbrial adhesion genes. Therefore, effective ETEC vaccines need to aim directly at all the enterotoxin antigens. The objective of this study was to evaluate the simultaneous immune effect of two live attenuated E. coli strains expressing LTR192G-STaA13Q and LTR192G-STb fusion immunogen, respectively. The results showed that both local mucosal and systemic immune responses against LT, STa, STb, and F41 were induced in BALB/c mice immunized orally with the recombinant E. coli strains ER-A and ER-B simultaneously. In addition, results of cellular immune responses showed that stimulation index (SI) values of immunized mice were significantly higher than control mice (P < 0.05) and a marked shift toward type-2 helper T lymphocyte (Th 2) immunity. Moreover, the induced antibodies demonstrated neutralizing effects on LT, STa, and STb producing E. coli infection. These data indicated that the use of recombinant E. coli ER-A and ER-B could be a valuable strategy for future polyvalent vaccine development of ETEC. PMID:25549617

  14. An efficient algorithm for encoding and decoding of raptor codes over the binary erasure channel

    NASA Astrophysics Data System (ADS)

    Zhang, Ya-Hang; Cheng, Bo-Wen; Zou, Guang-Nan; Wen, Wei-Ping; Qing, Si-Han

    2009-12-01

    As the most advanced rateless fountain codes, Systematic Raptor codes has been adopted by the 3GPP standard as a forward error correction scheme in Multimedia Broadcast/Multicast Services (MBMS). It has been shown to be an efficient channel coding technique which guarantees high symbol diversity in overlay networks. The 3GPP standard outlined a time-efficient maximum-likelihood (ML) decoding scheme that can be implemented using Gaussian elimination. But when the number of encoding symbols grows large, Gaussian elimination need to deal with a large matrix with O (K3) binary arithmetic operations, so the larger K becomes, the worse ML decoding scheme performs. This paper presents a better time-efficient encoding and decoding scheme while maintaining the same symbol recoverable performance, this encoding and decoding scheme is named Rapid Raptor Code. It will be shown that the proposed Rapid Raptor code Scheme significantly improves traditional Raptor codes' efficiency while maintaining the same performance.

  15. Arsenic Removal from Drinking Water by Iron Removal - U.S. EPA Demonstration Project at Northeastern Elementary School in Fountain City, IN - Final Performance Evaluation Report

    EPA Science Inventory

    This report documents the activities performed and the results obtained from the arsenic removal treatment technology demonstration project at Northeastern Elementary School in Fountain City, IN. The main objective of the project was to evaluate the effectiveness of US Water Sys...

  16. Long term therapy with a new liquid L-thyroxine preparation: bioequivalence with L-T4 tablets.

    PubMed

    Carpi, A; Toni, M G; Maccheroni, M; De Gaudio, C

    1992-12-01

    Seventy-four euthyroid patients with nodular goiter (55) or primary hypothyroidism (19) were selected for long term treatment with a new preparation containing L-T4 in solution (Tiroxen, Laboratori Baldacci, Pisa, Italy). Each patient underwent, before or after receiving the L-T4 in solution, long term treatment with L-T4 in tablet form at the same dose. The serum concentrations of TSH, TT4, TT3, FT4 and FT3 were measured basally and during therapy with each of the two L-T4 preparations (liquid and tablet). In the golter group, mean serum TSH concentration was 1.4 microUI/ml basally, while it was 0.47 microUI/ml following both L-T4 tablet therapy and L-T4 solution administration. Mean basal TSH value was significantly different from the two values on the therapy (p < 0.001 in each instance). Mean basal serum TT4 concentration was 8.2 +/- 0.25 microgram/dl basally while it was 9.9 +/- 0.28 microgram/dl (p < 0.001) on L-T4 tablet therapy and 9.7 +/- 0.26 (p < 0.001) on L-T4 solution administration. Mean basal serum concentration of TT3, FT4, FT3 was not significantly different from the value on the therapy, either with L-T4 tablet or with L-T4 solution. In the hypothyroid patients the high mean basal serum TSH concentration (23.6 microUI/ml) returned to normal similar values on L-T4 tablet therapy (0.96 microUI/ml; p < 0.01) and on L-T4 solution administration (1.24 microUI/ml; p < 0.01). The serum TSH concentration value during L-T4 therapy varied from unmeasurable level to 3.5 microUI/ml during the tablet administration and to 4.8 microUI/ml during the solution administration.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1285037

  17. A new intense lava fountain episode at Voragine crater (Mt. Etna): the event of 3 December 2015

    NASA Astrophysics Data System (ADS)

    Andronico, Daniele; Bonadonna, Costanza; Cioni, Raffaello; Cristaldi, Antonio; Pascual, Aurélie Joy; Russo, Alessandro; Scollo, Simona

    2016-04-01

    On 3 December 2015 Voragine crater, one of the five summit craters of Mt. Etna (Italy), produced a powerful lava fountain. The last paroxysmal episodes from this crater had occurred on July 1998 and September 1999; both events had been very intense, the first one classified as subPlinian and the latter causing significant disruption to road traffic due dense tephra sedimentation. Afterward, the Voragine entered in a period of relative quiescence interrupted by short events of Strombolian activity and weak ash emissions. In August 2015 the crater resumed its activity with discontinuous ash puffs that were followed by periods of relatively intense ash blasts in September. In October, this activity was clearly replaced by weak, pulsating Strombolian explosions confined inside the crater, which was several tens of meter deep. Gradually the Strombolian blasts became more continuous and intense and lapilli started to sediment around the crater rim. In the night between 2 and 3 December, the increase of seismic tremor coevally to the Strombolian activity heralded the lava fountain episode. During the paroxysm, that lasted around 40 minutes, vigorous magma jets were also produced by the adjacent Bocca Nuova summit crater, contributing to form a unique eruption column up to at least 7-8 km above the volcano and dispersed to the NE. Lighting was recurrently observed inside the column. Field survey, carried out between 3 and 5 December from a distance of 5 km from the vent, allowed to map the fallout dispersal and collect tephra samples. Estimation of uncertainty associated with ash sampling were also performed. Due to low-intense winds, the fallout mostly affected the area close to the volcanic slopes, but it also reached both the Tyrrhenian Sea to the N and the Ionian Sea to the E, more than 100 km of distance from the crater. Measurements of shape and density on the largest clasts collected within the first km from the Voragine were performed. Furthermore, we measured the

  18. Upward Bound: An Untapped Fountain Of Youth Wanting To Learn About Math And Science

    NASA Astrophysics Data System (ADS)

    Gillis-Davis, J. J.; Sherman, S. B.; Gillis-Davis, L. C.; Svelling, K. L.

    2009-12-01

    , physics, math, and engineering. In addition, learning science through inquiry and experimentation lends tangible examples to abstract principles. Our curricula (available on-line for sharing) are comprised of (1) modular classroom lesson plans, (2) teacher tutorials, and (3) hands-on laboratory experiments. Each set of summer classes has a theme; the first set of summer classes centered on factors that affect climate on any planet. For example, students measured solar activity by counting sunspots and learned about the greenhouse effect by conducting experiments with colored bottles. The second summer focused on how the electromagnetic spectrum is fundamental to remote sensing. During our summer 2009 program the Lunar Reconnaissance Orbiter launched, and with its many instruments served as a shining example of how the electromagnetic spectrum is used to study planetary bodies. Thus, NASA archived and student-collected data sets used in a PBL setting provide the basic foundation for helping students learn science and math concepts, while the UB programs ensure sustainability by providing a fountain of youth who want to learn.

  19. A laser-cooled cesium fountain frequency standard and a measurement of the frequency shift due to ultra-cold collisions

    NASA Technical Reports Server (NTRS)

    Gibble, Kurt; Kasapi, Steven; Chu, Steven

    1993-01-01

    A frequency standard based on an atomic fountain of cesium atoms may have an accuracy of 10(exp -16) due to longer interaction times and smaller anticipated systematic errors. All of the known systematic effects that now limit the accuracy of the Cs frequency standard increase either linearly or as some higher power of the atom's velocity. The one systematic frequency shift which is dramatically different is the frequency shift due to the collisions between the laser cooled atoms. At a temperature of a few micro-K, the de Broglie wavelength (lambda(sub deB) = h/p, where h is Planck's constant and p is the momentum of the atom) is much larger than the scale of the interatomic potential. Under these conditions the collision cross sections can be as large as (lambda(sub deB)(sup 2))/Pi and the frequency shift due to these collisions was recently calculated. In our Cs atomic fountain, we laser cooled and trapped 10(exp 10) Cs atoms in 0.4 s. By shifting the frequencies of the laser beams, the atoms were launched upwards at 2.5 m/s and a fraction of the atoms were optically pumped into the F=3 ground state. The unwanted atoms in the F=4 ground state were removed from the fountain with radiation pressure from a laser beam tuned to excite only those atoms. The Cs atoms in the F=3 state traveled ballistically upwards, were excited by the microwave cavity, and then returned back through the same cavity in the atomic fountain configuration. By varying the cold atom density, a density dependent shift of -12.9 +/- 0.7 mHz or -1.4 x 10-12 for an average fountain density of (2.7 +/- 1.5) 10(exp 9) atoms/cm(sup 3) was measured.

  20. CysLT1 Receptor Is Protective against Oxidative Stress in a Model of Irritant-Induced Asthma.

    PubMed

    McGovern, Toby; Goldberger, Madison; Chen, Michael; Allard, Benoit; Hamamoto, Yoichiro; Kanaoka, Yoshihide; Austen, K Frank; Powell, William S; Martin, James G

    2016-07-01

    The bronchoconstrictive and proinflammatory properties of cysteinyl leukotrienes (cysLTs) in allergic asthma mediate their effects predominantly through the cysLT1 receptor (cysLT1R). However, the role of cysLTs and cysLT1R in innate immune-triggered asthma is largely unexplored. We explored the synthesis of cysLTs and cysLT1R as determinants of airway responses in an oxidative stress-induced model of irritant asthma. Wild-type (WT) mice exposed to 100 ppm Cl2 for 5 min had airway neutrophilia, increased cysLT production, and pulmonary expression of cysLT-related biosynthetic genes. CysLT1R-deficient (CysLTr1(-/-)) mice that were exposed to Cl2 demonstrated airway hyperresponsiveness to inhaled methacholine significantly greater than in WT BALB/c mice. Compared to WT mice, airway neutrophilia and keratinocyte chemoattractant production levels were higher in CysLTr1(-/-) mice and airway hyperresponsiveness was ameliorated using a granulocyte depletion Ab. CysLTr1(-/-) mice also demonstrated prolonged bronchial epithelial cell apoptosis following Cl2 WT mice showed increased antioxidant and NF erythroid 2-related factor 2 (Nrf2) gene expression, Nrf2 nuclear translocation in bronchial epithelial cells, and increased reduced glutathione/oxidized glutathione following Cl2 exposure whereas CysLTr1(-/-) mice did not. Furthermore, CysLTr1(-/-) mice demonstrated increased pulmonary E-cadherin expression and soluble E-cadherin shedding compared with WT mice. Loss of a functional cysLT1R results in aberrant antioxidant response and increased susceptibility to oxidative injury, apparently via a cysLT1R-dependent impairment of Nrf2 function. PMID:27226094

  1. Measurement of the blackbody radiation shift of the {sup 133}Cs hyperfine transition in an atomic fountain

    SciTech Connect

    Levi, Filippo; Calonico, Davide; Lorini, Luca; Micalizio, Salvatore; Godone, Aldo

    2004-09-01

    We used a Cs fountain to measure the Stark shift of the ground-state hyperfine transition frequency in cesium (9.2 GHz) due to the electric field of the blackbody radiation. The relative shift at 300 K deduced from our measurements, including the leading and the second-order term in temperature, is (-1.45{+-}0.09)x10{sup -14} and agrees with our recent theoretical evaluation (-1.51{+-}0.07)x10{sup -14} [Micalizio et al. Phys. Rev. A 69, 053401 (2004)]. These values differ from that currently used (-1.735{+-}0.003)x10{sup -14}, with significant implications on frequency standards accuracy, on clocks comparison and on a variety of high-precision physics tests, such as the time stability of fundamental constants.

  2. Artificial-recharge tests in Upper Black Squirrel Creek basin, Jimmy Camp Valley, and Fountain Valley, El Paso County, Colorado

    USGS Publications Warehouse

    Emmons, P.J.

    1977-01-01

    Artificial-recharge tests were conducted in the alluvium in upper Black Squirrel Creek basin, the alluvium in Jimmy Camp Valley, and in the alluvium overlying the Widefield aquifer which is located in an ancestral channel in Fountain Valley, Colo. Nine artificial-recharge pits with areas of approximately 9,200 square feet each were excavated in the unsaturated zones above the three aquifers. Each artificial-recharge site was instrumented to measure inflow, stage fluctuations, and water-table fluctuations. Artificial-recharge tests of approximately 10 days ' duration were conducted at each of the nine artificial-recharge sites and one extended test of approximately 30 days ' duration was conducted in each of the three study areas. Periphyton growth, present in most of the artificial-recharge ponds, was insufficient to cause noticeable decline in the rate of infiltration. (Woodard-USGS)

  3. Decadal evolution of a degassing magma reservoir unravelled from fire fountains produced at Etna volcano (Italy) between 1989 and 2001

    NASA Astrophysics Data System (ADS)

    Vergniolle, Sylvie; Gaudemer, Yves

    2012-04-01

    Between 1989 and 2001, five eruptions at Etna displayed a regular alternation between repose periods and episodes rich in gas, termed quasi-fire fountains and consisting of a series of Strombolian explosions sometimes leading to a fire fountain. This behaviour results from the coalescence of a foam layer trapped at the top of the reservoir which was periodically rebuilt prior to each episode (Vergniolle and Jaupart, J Geophys Res 95:2793-2809, 1990). Visual observations of fire fountains are combined with the foam dynamics to estimate the five degassing parameters characteristic of the degassing reservoir, i.e. the number of bubbles, gas volume fraction, bubble diameter, reservoir thickness and reservoir volume. The study of decadal cycles of eruptive patterns (Allard et al., Earth Sci Rev 78:85-114, 2006) suggests that the first eruption with fire fountains occurred in 1995 while the last one happened in 2001. The number of bubbles and the gas volume fraction increase smoothly from the beginning of the cycle (1995) to its end (2001). The increasing number of bubbles per cubic metre, from 0.61-20×105 to 0.1-3.4×109, results from cooling of the magma within the reservoir. The simultaneously decreasing bubble diameter, from 0.67-0.43 to 0.30-0.19 mm, is related to the decreasing amount of dissolved volatiles. Meanwhile, the thickness and the volume of the degassing reservoir diminish, from values typical of the magma reservoir to values characteristic of a very thin bubbly layer, marking the quasi-exhaustion of volatiles. The magma reservoir has a slender vertical shape, with a maximum thickness of 3,300-8,200 m and a radius of 240 m (Vergniolle 2008), making its detection from seismic studies difficult. Its volume, at most 0.58-1.4 km3, is in agreement with geochemical studies (0.5 km3) (Le Cloarec and Pennisi, J Volcanol Geotherm Res 108:141-155, 2001). The time evolution of both the total gas volume expelled per eruption, and the inter-eruptive gas flux results

  4. Low intensity hawaiian fountaining as exemplified by the March 2011, Kamoamoa eruption at Kilauea Volcano, Hawai`i (Invited)

    NASA Astrophysics Data System (ADS)

    Orr, T. R.; Houghton, B. F.; Poland, M. P.; Patrick, M. R.; Thelen, W. A.; Sutton, A. J.; Parcheta, C. E.; Thornber, C. R.

    2013-12-01

    The latest 'classic' hawaiian high-fountaining activity at Kilauea Volcano occurred in 1983-1986 with construction of the Pu`u `O`o pyroclastic cone. Since then, eruptions at Kilauea have been dominated by nearly continuous effusive activity. Episodes of sustained low hawaiian fountaining have occurred but are rare and restricted to short-lived fissure eruptions along Kilauea's east rift zone. The most recent of these weakly explosive fissure eruptions--the Kamoamoa eruption--occurred 5-9 March 2011. The Kamoamoa eruption was probably the consequence of a decrease in the carrying capacity of the conduit feeding the episode 58 eruptive vent down-rift from Pu`u `O`o in Kilauea's east rift zone. As output from the vent waned, Kilauea's summit magma storage and east rift zone transport system began to pressurize, as manifested by an increase in seismicity along the upper east rift zone, inflation of the summit and Pu`u `O`o, expansion of the east rift zone, and rising lava levels at both the summit and Pu`u `O`o. A dike began propagating towards the surface from beneath Makaopuhi Crater, 6 km west of Pu`u `O`o, at 1342 Hawaiian Standard Time (UTC - 10 hours) on 5 March. A fissure eruption started about 3.5 hours later near Nāpau Crater, 2 km uprift of Pu`u `O`o. Activity initially jumped between numerous en echelon fissure segments before centering on discrete vents near both ends of the 2.4-km-long fissure system for the final two days of the eruption. About 2.6 mcm of lava was erupted over the course of four days with a peak eruption rate of 11 m3/s. The petrologic characteristics of the fissure-fed lava indicate mixing between hotter mantle-derived magma and cooler rift-stored magma, with a greater proportion of the cooler component than was present in east rift zone lava erupting before March 2011. The fissure eruption was accompanied by the highest SO2 emission rates since 1986. Coincidentally, the summit and Pu`u `O`o deflated as magma drained away, causing

  5. A tripartite fusion, FaeG-FedF-LT(192)A2:B, of enterotoxigenic Escherichia coli (ETEC) elicits antibodies that neutralize cholera toxin, inhibit adherence of K88 (F4) and F18 fimbriae, and protect pigs against K88ac/heat-labile toxin infection.

    PubMed

    Ruan, Xiaosai; Liu, Mei; Casey, Thomas A; Zhang, Weiping

    2011-10-01

    Enterotoxigenic Escherichia coli (ETEC) strains expressing K88 (F4) or F18 fimbriae and heat-labile (LT) and/or heat-stable (ST) toxins are the major cause of diarrhea in young pigs. Effective vaccines inducing antiadhesin (anti-K88 and anti-F18) and antitoxin (anti-LT and anti-ST) immunity would provide broad protection to young pigs against ETEC. In this study, we genetically fused nucleotides coding for peptides from K88ac major subunit FaeG, F18 minor subunit FedF, and LT toxoid (LT(192)) A2 and B subunits for a tripartite adhesin-adhesin-toxoid fusion (FaeG-FedF-LT(192)A2:B). This fusion was used for immunizations in mice and pigs to assess the induction of antiadhesin and antitoxin antibodies. In addition, protection by the elicited antiadhesin and antitoxin antibodies against a porcine ETEC strain was evaluated in a gnotobiotic piglet challenge model. The data showed that this FaeG-FedF-LT(192)A2:B fusion elicited anti-K88, anti-F18, and anti-LT antibodies in immunized mice and pigs. In addition, the anti-porcine antibodies elicited neutralized cholera toxin and inhibited adherence against both K88 and F18 fimbriae. Moreover, immunized piglets were protected when challenged with ETEC strain 30302 (K88ac/LT/STb) and did not develop clinical disease. In contrast, all control nonvaccinated piglets developed severe diarrhea and dehydration after being challenged with the same ETEC strain. This study clearly demonstrated that this FaeG-FedF-LT(192)A2:B fusion antigen elicited antibodies that neutralized LT toxin and inhibited the adherence of K88 and F18 fimbrial E. coli strains and that this fusion could serve as an antigen for vaccines against porcine ETEC diarrhea. In addition, the adhesin-toxoid fusion approach used in this study may provide important information for developing effective vaccines against human ETEC diarrhea. PMID:21813665

  6. Repeated detection of microbes in beverages dispensed from soda fountain machines and the effect of flushing on microbial density.

    PubMed

    Godard, Renee D; Sharma, Puja; Wagner, Carlie Jo; Wilson, C Morgan; Fleming-Haddock, Amie; Beach, Rebecca L

    2013-05-15

    Few studies have examined patterns of microbial contamination in soda fountain beverages. In this study, patterns of microbial contamination in beverages dispensed from soda fountain machines (SFMs) sampled in June 2009 and then again 13 months later were compared. Over 70% of beverages contained microbes in both years, suggesting that contamination of beverages dispensed from SFMs can continue for long periods of time. In addition, the impact of disinfecting the dispensing nozzles and plastic tubing of SFMs, as well as the impact of machine use on microbial contamination was assessed. Managers from 26 establishments (fast-food and convenience stores) were interviewed about their SFM disinfecting practices and no correlation was found between the self-reported disinfecting practices and levels of microbial contamination in beverages dispensed from SFMs. Furthermore, in a direct study of two SFMs with an established disinfecting regimen, CFU/mL in beverages increased significantly immediately after disinfecting of plastic tubing yet returned to pre-disinfecting concentrations within 11 days. These results suggest that disinfecting may disturb microbial communities, resulting in increased planktonic microbes, but not the ultimate removal of communities themselves. Additionally, samples of a sugar and a diet soda were collected from 15 different SFMs before and after dispensing of ~0.95 L (the approximate size of a large beverage cup). Samples collected before dispensing this volume had significantly higher microbial counts than those collected after, suggesting that planktonic microbes in the beverage lines had been reduced by flushing. As there are currently no regulations regarding the disinfecting of SFM tubing or periodic inspections of beverages dispensed from SFMs, it would be valuable for consumers to encourage increased surveillance of SFMs, and to dispense some beverage before filling their cups. PMID:23562835

  7. Characterization of a Mutant Escherichia coli Heat-Labile Toxin, LT(R192G/L211A), as a Safe and Effective Oral Adjuvant ▿

    PubMed Central

    Norton, Elizabeth B.; Lawson, Louise B.; Freytag, Lucy C.; Clements, John D.

    2011-01-01

    Despite the fact that the adjuvant properties of the heat-labile enterotoxins of Escherichia coli (LT) and Vibrio cholerae (CT) have been known for more than 20 years, there are no available oral vaccines containing these molecules as adjuvants, primarily because they are both very potent enterotoxins. A number of attempts with various degrees of success have been made to reduce or eliminate the enterotoxicity of LT and CT so they can safely be used as oral adjuvants or immunogens. In this report we characterize the structural, enzymatic, enterotoxic, and adjuvant properties of a novel mutant of LT, designated LT(R192G/L211A), or dmLT. dmLT was not sensitive to trypsin activation, had reduced enzymatic activity for induction of cyclic AMP in Caco-2 cells, and exhibited no enterotoxicity in the patent mouse assay. Importantly, dmLT retained the ability to function as an oral adjuvant for a coadministered antigen (tetanus toxoid) and to elicit anti-LT antibodies. In vitro and in vivo data suggest that the reduced enterotoxicity of this molecule compared to native LT or the single mutant, LT(R192G), is a consequence of increased sensitivity to proteolysis and rapid intracellular degradation in mammalian cells. In conclusion, dmLT is a safe and powerful detoxified enterotoxin with the potential to function as a mucosal adjuvant for coadministered antigens and to elicit anti-LT antibodies without undesirable side effects. PMID:21288994

  8. Characterization of a mutant Escherichia coli heat-labile toxin, LT(R192G/L211A), as a safe and effective oral adjuvant.

    PubMed

    Norton, Elizabeth B; Lawson, Louise B; Freytag, Lucy C; Clements, John D

    2011-04-01

    Despite the fact that the adjuvant properties of the heat-labile enterotoxins of Escherichia coli (LT) and Vibrio cholerae (CT) have been known for more than 20 years, there are no available oral vaccines containing these molecules as adjuvants, primarily because they are both very potent enterotoxins. A number of attempts with various degrees of success have been made to reduce or eliminate the enterotoxicity of LT and CT so they can safely be used as oral adjuvants or immunogens. In this report we characterize the structural, enzymatic, enterotoxic, and adjuvant properties of a novel mutant of LT, designated LT(R192G/L211A), or dmLT. dmLT was not sensitive to trypsin activation, had reduced enzymatic activity for induction of cyclic AMP in Caco-2 cells, and exhibited no enterotoxicity in the patent mouse assay. Importantly, dmLT retained the ability to function as an oral adjuvant for a coadministered antigen (tetanus toxoid) and to elicit anti-LT antibodies. In vitro and in vivo data suggest that the reduced enterotoxicity of this molecule compared to native LT or the single mutant, LT(R192G), is a consequence of increased sensitivity to proteolysis and rapid intracellular degradation in mammalian cells. In conclusion, dmLT is a safe and powerful detoxified enterotoxin with the potential to function as a mucosal adjuvant for coadministered antigens and to elicit anti-LT antibodies without undesirable side effects. PMID:21288994

  9. Speech coding

    NASA Astrophysics Data System (ADS)

    Gersho, Allen

    1990-05-01

    Recent advances in algorithms and techniques for speech coding now permit high quality voice reproduction at remarkably low bit rates. The advent of powerful single-ship signal processors has made it cost effective to implement these new and sophisticated speech coding algorithms for many important applications in voice communication and storage. Some of the main ideas underlying the algorithms of major interest today are reviewed. The concept of removing redundancy by linear prediction is reviewed, first in the context of predictive quantization or DPCM. Then linear predictive coding, adaptive predictive coding, and vector quantization are discussed. The concepts of excitation coding via analysis-by-synthesis, vector sum excitation codebooks, and adaptive postfiltering are explained. The main idea of vector excitation coding (VXC) or code excited linear prediction (CELP) are presented. Finally low-delay VXC coding and phonetic segmentation for VXC are described.

  10. Survey of A{sub LT'} asymmetries in semi-exclusive electron scattering on He4 and C12

    SciTech Connect

    Dan Protopopescu; et. Al.

    2005-02-21

    Single spin azimuthal asymmetries A{sub LT'} were measured at Jefferson Lab using 2.2 and 4.4 GeV longitudinally polarized electrons incident on {sup 4}He and {sup 12}C targets in the CLAS detector. A{sub LT'} is related to the imaginary part of the longitudinal-transverse interference and in quasifree nucleon knockout it provides an unambiguous signature for final state interactions (FSI). Experimental values of A{sub LT'} were found to be below 5%, typically |A{sub LT'}| < 3% for data with good statistical precision. Optical Model in Eikonal Approximation (OMEA) and Relativistic Multiple-Scattering Glauber Approximation (RMSGA) calculations are shown to be consistent with the measured asymmetries.

  11. Uplink Coding

    NASA Technical Reports Server (NTRS)

    Pollara, Fabrizio; Hamkins, Jon; Dolinar, Sam; Andrews, Ken; Divsalar, Dariush

    2006-01-01

    This viewgraph presentation reviews uplink coding. The purpose and goals of the briefing are (1) Show a plan for using uplink coding and describe benefits (2) Define possible solutions and their applicability to different types of uplink, including emergency uplink (3) Concur with our conclusions so we can embark on a plan to use proposed uplink system (4) Identify the need for the development of appropriate technology and infusion in the DSN (5) Gain advocacy to implement uplink coding in flight projects Action Item EMB04-1-14 -- Show a plan for using uplink coding, including showing where it is useful or not (include discussion of emergency uplink coding).

  12. Evaluating the A-Subunit of the Heat-Labile Toxin (LT) As an Immunogen and a Protective Antigen Against Enterotoxigenic Escherichia coli (ETEC)

    PubMed Central

    Norton, Elizabeth B.; Branco, Luis M.; Clements, John D.

    2015-01-01

    Diarrheal illness contributes to malnutrition, stunted growth, impaired cognitive development, and high morbidity rates in children worldwide. Enterotoxigenic Escherichia coli (ETEC) is a major contributor to this diarrheal disease burden. ETEC cause disease in the small intestine by means of colonization factors and by production of a heat-labile enterotoxin (LT) and/or a small non-immunogenic heat-stable enterotoxin (ST). Overall, the majority of ETEC produce both ST and LT. LT induces secretion via an enzymatically active A-subunit (LT-A) and a pentameric, cell-binding B-subunit (LT-B). The importance of anti-LT antibodies has been demonstrated in multiple clinical and epidemiological studies, and a number of potential ETEC vaccine candidates have included LT-B as an important immunogen. However, there is limited information about the potential contribution of LT-A to development of protective immunity. In the current study, we evaluate the immune response against the A-subunit of LT as well as the A-subunit’s potential as a protective antigen when administered alone or in combination with the B-subunit of LT. We evaluated human sera from individuals challenged with a prototypic wild-type ETEC strain as well as sera from individuals living in an ETEC endemic area for the presence of anti-LT, anti-LT-A and anti-LT-B antibodies. In both cases, a significant number of individuals intentionally or endemically infected with ETEC developed antibodies against both LT subunits. In addition, animals immunized with the recombinant proteins developed robust antibody responses that were able to neutralize the enterotoxic and cytotoxic effects of native LT by blocking binding and entry into cells (anti-LT-B) or the intracellular enzymatic activity of the toxin (anti-LT-A). Moreover, antibodies to both LT subunits acted synergistically to neutralize the holotoxin when combined. Taken together, these data support the inclusion of both LT-A and LT-B in prospective vaccines

  13. Type II heat-labile enterotoxins from 50 diverse Escherichia coli isolates belong almost exclusively to the LT-IIc family and may be prophage encoded.

    PubMed

    Jobling, Michael G; Holmes, Randall K

    2012-01-01

    Some enterotoxigenic Escherichia coli (ETEC) produce a type II heat-labile enterotoxin (LT-II) that activates adenylate cyclase in susceptible cells but is not neutralized by antisera against cholera toxin or type I heat-labile enterotoxin (LT-I). LT-I variants encoded by plasmids in ETEC from humans and pigs have amino acid sequences that are ≥ 95% identical. In contrast, LT-II toxins are chromosomally encoded and are much more diverse. Early studies characterized LT-IIa and LT-IIb variants, but a novel LT-IIc was reported recently. Here we characterized the LT-II encoding loci from 48 additional ETEC isolates. Two encoded LT-IIa, none encoded LT-IIb, and 46 encoded highly related variants of LT-IIc. Phylogenetic analysis indicated that the predicted LT-IIc toxins encoded by these loci could be assigned to 6 subgroups. The loci corresponding to individual toxins within each subgroup had DNA sequences that were more than 99% identical. The LT-IIc subgroups appear to have arisen by multiple recombinational events between progenitor loci encoding LT-IIc1- and LT-IIc3-like variants. All loci from representative isolates encoding the LT-IIa, LT-IIb, and each subgroup of LT-IIc enterotoxins are preceded by highly-related genes that are between 80 and 93% identical to predicted phage lysozyme genes. DNA sequences immediately following the B genes differ considerably between toxin subgroups, but all are most closely related to genomic sequences found in predicted prophages. Together these data suggest that the LT-II loci are inserted into lambdoid type prophages that may or may not be infectious. These findings raise the possibility that production of LT-II enterotoxins by ETEC may be determined by phage conversion and may be activated by induction of prophage, in a manner similar to control of production of Shiga-like toxins by converting phages in isolates of enterohemmorhagic E. coli. PMID:22242186

  14. Evaluating the A-Subunit of the Heat-Labile Toxin (LT) As an Immunogen and a Protective Antigen Against Enterotoxigenic Escherichia coli (ETEC).

    PubMed

    Norton, Elizabeth B; Branco, Luis M; Clements, John D

    2015-01-01

    Diarrheal illness contributes to malnutrition, stunted growth, impaired cognitive development, and high morbidity rates in children worldwide. Enterotoxigenic Escherichia coli (ETEC) is a major contributor to this diarrheal disease burden. ETEC cause disease in the small intestine by means of colonization factors and by production of a heat-labile enterotoxin (LT) and/or a small non-immunogenic heat-stable enterotoxin (ST). Overall, the majority of ETEC produce both ST and LT. LT induces secretion via an enzymatically active A-subunit (LT-A) and a pentameric, cell-binding B-subunit (LT-B). The importance of anti-LT antibodies has been demonstrated in multiple clinical and epidemiological studies, and a number of potential ETEC vaccine candidates have included LT-B as an important immunogen. However, there is limited information about the potential contribution of LT-A to development of protective immunity. In the current study, we evaluate the immune response against the A-subunit of LT as well as the A-subunit's potential as a protective antigen when administered alone or in combination with the B-subunit of LT. We evaluated human sera from individuals challenged with a prototypic wild-type ETEC strain as well as sera from individuals living in an ETEC endemic area for the presence of anti-LT, anti-LT-A and anti-LT-B antibodies. In both cases, a significant number of individuals intentionally or endemically infected with ETEC developed antibodies against both LT subunits. In addition, animals immunized with the recombinant proteins developed robust antibody responses that were able to neutralize the enterotoxic and cytotoxic effects of native LT by blocking binding and entry into cells (anti-LT-B) or the intracellular enzymatic activity of the toxin (anti-LT-A). Moreover, antibodies to both LT subunits acted synergistically to neutralize the holotoxin when combined. Taken together, these data support the inclusion of both LT-A and LT-B in prospective vaccines

  15. Silver Linings: Using Cloud Maps to Understand the L/T Spectral Transtion

    NASA Astrophysics Data System (ADS)

    Radigan, Jacqueline

    2013-10-01

    Recent observations in the time domain have revealed large amplitude variability for a subset of objects at the transition between cloudy L and clear T spectral types, indicative of patchy cloud coverage. We propose to obtain time-resolved near-infrared spectra of two highly variable L/T transition brown dwarfs and an unusually blue L dwarf in order to make spectrally and spatially resolved maps of their surfaces. By decomposing the spectral time series into principal components we can determine the number of different surface spectra that contribute to the variability and test whether the current paradigm--namely that variability for these objects results due to holes in the cloud layer--is accurate. Our previous Cycle 18 observations {GO12314, PI:Apai} of two early T-dwarfs suggest a simple two-surface scenario where variability across a wide range of atmospheric pressures is correlated, and presumably governed by the horizontal distribution of condensates {Apai, Radigan & Buenzli et al., submitted}, while the behavior of a T6.5 dwarf was observed to be significantly more complex {Buenzli et al. 2012}. While these data are suggestive, a pattern cannot be inferred from observations of only two objects. The proposed observations will double the sample of variable L/T transition objects mapped with WFC3 grism spectroscopy from 2 to 4, and allow us to establish a pattern; namely, do all L/T transition objects share similar spectral variations, indicative of a common mechanism and number of surface components? We will then investigate whether this pattern extends to unusually blue L-dwarfs, also hypothesized to have patchy clouds.

  16. Field measurements and interpretation of TMI-2 instrumentation: CF-2-LT2

    SciTech Connect

    Jones, J E; Smith, J T; Mathis, M V

    1982-01-01

    This report describes the measurements and results of the Core Flood Tank 1A level monitor CF-2-LT2. This instrument consists of a Bailey Type BY Process Computer Transmitter connected to a readout module by approximately 500 feet of cable through a penetration junction and an instrument mounting junction. The status of this instrument is uncertain, but it was producing a reasonable output reading which implied it had not failed. As a result, measurements on this instrument were designed to determine if it were properly functioning.

  17. [Rhizopus microsporus strain UzLT-I--a thermotolerant producer of lipase].

    PubMed

    Zakirov, M Z; Sultanova, I G; Davranov, K

    1975-01-01

    The properties of the thermotolerant fungus Rhizopus microsporus strain UzLT-1--producer of lipolyptic enzymes are described. Optimal cultivation conditions--40 degrees, C, pH 4.5--Are determined. The lipolytic activity of the culture on the medium consisting of corn extract (2%), cotton-seed oil (1%) and water is 850 ml 0.1 n KOH per 100 ml culture liquid. The enzymic preparations of lipase have been precipitated by isopropanol and ammonium sulphate. The preparation precipitated by isopropanol shows its macimum activity at pH 4.2 and 7.8 and a temperature of 40--50 degrees C. PMID:1738

  18. Operation of NIM5 fountain with 1.5x10-15 uncertainty and design of new NIM6 in NIM

    NASA Astrophysics Data System (ADS)

    Fang, F.; Liu, N.; Liu, K.; Chen, W.; Suo, R.; Li, Tianchu

    2016-06-01

    The cesium fountain primary frequency standard NIM5 started to operate since 2008 and started to report to BIPM since 2014. The major constrains of NIM5 is a relatively large background signal at the detection and microwave leakages due to the Ramsey cavity. A new fountain clock NIM6 is under construction. Besides some improvements on the vacuum system, a new Ramsey cavity and a microwave synthesizer are made to reduce the Type B uncertainty. Another feature of NIM6 is collecting atoms from a MOT loading optical molasses to get more atoms with a more uniform density distribution. With a new frequency synthesizer based on cryogenic sapphire oscillator (CSO), NIM6 is aiming to reach the quantum projection noise, thus leading to a reduced Type A uncertainty compared with NIM5.

  19. Lava fountain heights at Pu'u 'O'o, Kilauea, Hawaii - Indicators of amount and variations of exsolved magma volatiles

    NASA Technical Reports Server (NTRS)

    Head, James W., III; Wilson, Lionel

    1987-01-01

    Factors most important in determining fountain height in Hawaiian-type basaltic eruptions were assessed on the basis of theoretical calculations and observations at Pu'u 'O'o vent, east rift zone of Kilauea, Hawaii. It is shown that fountain height is very sensitive to changes in exsolved gas content (and, thus, can be used to estimate variability in exsolved gas content) and relatively insensitive to large variations in volume flux. Volume flux was found to be the most important parameter determining the equilibrium vent diameter. The results of calculations also indicate that there was a general increase in magma gas content over the first 20 episodes of the Pu'u 'O'o eruption and that gas depletion took place in the conduit beneath the vent during repose periods.

  20. Description and User Manual for a Web-Based Interface to a Transit-Loss Accounting Program for Monument and Fountain Creeks, El Paso and Pueblo Counties, Colorado

    USGS Publications Warehouse

    Kuhn, Gerhard; Krammes, Gary S.; Beal, Vivian J.

    2007-01-01

    The U.S. Geological Survey, in cooperation with Colorado Springs Utilities, the Colorado Water Conservation Board, and the El Paso County Water Authority, began a study in 2004 with the following objectives: (1) Apply a stream-aquifer model to Monument Creek, (2) use the results of the modeling to develop a transit-loss accounting program for Monument Creek, (3) revise an existing accounting program for Fountain Creek to easily incorporate ongoing and future changes in management of return flows of reusable water, and (4) integrate the two accounting programs into a single program and develop a Web-based interface to the integrated program that incorporates simple and reliable data entry that is automated to the fullest extent possible. This report describes the results of completing objectives (2), (3), and (4) of that study. The accounting program for Monument Creek was developed first by (1) using the existing accounting program for Fountain Creek as a prototype, (2) incorporating the transit-loss results from a stream-aquifer modeling analysis of Monument Creek, and (3) developing new output reports. The capabilities of the existing accounting program for Fountain Creek then were incorporated into the program for Monument Creek and the output reports were expanded to include Fountain Creek. A Web-based interface to the new transit-loss accounting program then was developed that provided automated data entry. An integrated system of 34 nodes and 33 subreaches was integrated by combining the independent node and subreach systems used in the previously completed stream-aquifer modeling studies for the Monument and Fountain Creek reaches. Important operational criteria that were implemented in the new transit-loss accounting program for Monument and Fountain Creeks included the following: (1) Retain all the reusable water-management capabilities incorporated into the existing accounting program for Fountain Creek; (2) enable daily accounting and transit

  1. Products of Submarine Fountains and Bubble-burst Eruptive Activity at 1200 m on West Mata Volcano, Lau Basin

    NASA Astrophysics Data System (ADS)

    Clague, D. A.; Rubin, K. H.; Keller, N. S.

    2009-12-01

    An eruption was observed and sampled at West Mata Volcano using ROV JASON II for 5 days in May 2009 during the NSF-NOAA eruption response cruise to this region of suspected volcanic activity. Activity was focused near the summit at the Prometheus and Hades vents. Prometheus erupted almost exclusively as low-level fountains. Activity at Hades cycled between vigorous degassing, low fountains, and bubble-bursts, building up and partially collapsing a small spatter/scoria cone and feeding short sheet-like and pillow flows. Fire fountains at Prometheus produced mostly small primary pyroclasts that include Pele's hair and fluidal fragments of highly vesicular volcanic glass. These fragments have mostly shattered and broken surfaces, although smooth spatter-like surfaces also occur. As activity wanes, glow in the vent fades, and denser, sometimes altered volcanic clasts are incorporated into the eruption. The latter are likely from the conduit walls and/or vent-rim ejecta, drawn back into the vent by inrushing seawater that replaces water entrained in the rising volcanic plume. Repeated recycling of previously erupted materials eventually produces rounded clasts resembling beach cobbles and pitted surfaces on broken phenocrysts of pyroxene and olivine. We estimate that roughly 33% of near vent ejecta are recycled. Our best sample of this ejecta type was deposited in the drawer of the JASON II ROV during a particularly large explosion that occurred during plume sampling immediately above the vent. Elemental sulfur spherules up to 5 mm in diameter are common in ejecta from both vents and occur inside some of the lava fragments Hades activity included dramatic bubble-bursts unlike anything previously observed under water. The lava bubbles, sometimes occurring in rapid-fire sequence, collapsed in the water-column, producing fragments that are quenched in less than a second to form Pele's hair, limu o Pele, spatter-like lava blobs, and scoria. All are highly vesicular

  2. FOREWORD: 27th International Conference on Low Temperature Physics (LT27)

    NASA Astrophysics Data System (ADS)

    Calzetta, Esteban

    2014-12-01

    The Low Temperature Physics Conference is an international event held every three years, under the auspices of the IUPAP through its Commission C5 on Low Temperature Physics. These conferences aim at the exchange of information and views among the members of the international scientific community in the general field of Low Temperature Physics, promoting the excellence of invited and contributed presentations. It is a tradition that LT offers updates on the various topics, provided by the highest representatives of the field, as well as oral and poster contributions in the different areas. LT27 was the first conference of the series that took place in South America. It was therefore a particular challenge for us and it is a source of pride to present these Proceedings as proof of the wonderful scientific atmosphere at the meeting. We wish to acknowledge our host institutions, sponsors, and the many people whose work made this meeting possible. Our appreciation goes to all of them, as well as to speakers and attendants.

  3. Simulation-Based e-Learning Tools for Science,Engineering, and Technology Education(SimBeLT)

    NASA Astrophysics Data System (ADS)

    Davis, Doyle V.; Cherner, Y.

    2006-12-01

    The focus of Project SimBeLT is the research, development, testing, and dissemination of a new type of simulation-based integrated e-learning set of modules for two-year college technical and engineering curricula in the areas of thermodynamics, fluid physics, and fiber optics that can also be used in secondary schools and four-year colleges. A collection of sophisticated virtual labs is the core component of the SimBeLT modules. These labs will be designed to enhance the understanding of technical concepts and underlying fundamental principles of these topics, as well as to master certain performance based skills online. SimBeLT software will help educators to meet the National Science Education Standard that "learning science and technology is something that students do, not something that is done to them". A major component of Project SimBeLT is the development of multi-layered technology-oriented virtual labs that realistically mimic workplace-like environments. Dynamic data exchange between simulations will be implemented and links with instant instructional messages and data handling tools will be realized. A second important goal of Project SimBeLT labs is to bridge technical skills and scientific knowledge by enhancing the teaching and learning of specific scientific or engineering subjects. SimBeLT builds upon research and outcomes of interactive teaching strategies and tools developed through prior NSF funding (http://webphysics.nhctc.edu/compact/index.html) (Project SimBeLT is partially supported by a grant from the National Science Foundation DUE-0603277)

  4. Cusp Ion Fountain Observations from the e-POP Suprathermal Electron Imager (SEI) with DMSP and RISR-N conjunctions

    NASA Astrophysics Data System (ADS)

    Shen, Y.; Knudsen, D. J.; Burchill, J. K.; Howarth, A. D.; Yau, A. W.; Redmon, R. J.

    2015-12-01

    Low-energy (<10 eV) ion upflows associated with ambipolar ion acceleration in the cusp/cleft and polar cap regions are investigated using conjunctions of the Enhanced Polar Outflow Probe (e-POP) satellite, the Resolute Bay Incoherent Scatter Radar (RISR-N) and the DMSP satellites in June 2014. e-POP encountered the cusp/cleft ion fountain at 10-14 MLT and around 1000 km altitude during these experiments. Such intermediate-altitude observations of ion upflow have been sampled only rarely by previous satellite missions and ground-based radars. The Suprathermal Electron Imager (SEI) onboard e-POP measures two-dimensional ion distribution functions with a frame rate of 100 images per second, from which, high-precision energy and angle information of entering ions can be inferred. Large field-aligned ion bulk flow velocities (2.5 km/s) are estimated from the angle information with a resolution of the order of 25 m/s. The ion velocities were, in general, upward in the cusp region and downward in the polar cap region. The ion temperatures have been resolved by investigating the slop shape of the distribution function. It has been found that only weak perpendicular (to B) heating occurred during these events, which when combined with the simultaneous soft electron precipitation observed by the DMSP SSJ/4 instrument, suggests that ambipolar electric fields play a dominant role in accelerating ions upward at and below 1000 km. Also, structured DC field-aligned currents derived from the magnetic field instrument (MGF) onboard e-POP are found to be well-correlated with upflow velocities. In addition, ion composition information is available from e-POP's ion mass spectrometer (IRM). Oxygen ions (O+) were found to dominate (85%) in the identified events, accompanied by a small fraction (15%) of hydrogen ions (H+) and helium ions (He+). We will compare these in situ measurements with RISR-N observations in order to further our understanding of the mechanisms responsible for, and

  5. Estimating eruption temperature from thermal emission spectra of lava fountain activity in the Erta'Ale (Ethiopia) volcano lava lake: Implications for observing Io's volcanoes

    USGS Publications Warehouse

    Davies, Ashley G.; Keszthelyi, Laszlo P.; McEwen, Alfred S.

    2011-01-01

    We have analysed high-spatial-resolution and high-temporal-resolution temperature measurements of the active lava lake at Erta'Ale volcano, Ethiopia, to derive requirements for measuring eruption temperatures at Io's volcanoes. Lava lakes are particularly attractive targets because they are persistent in activity and large, often with ongoing lava fountain activity that exposes lava at near-eruption temperature. Using infrared thermography, we find that extracting useful temperature estimates from remote-sensing data requires (a) high spatial resolution to isolate lava fountains from adjacent cooler lava and (b) rapid acquisition of multi-color data. Because existing spacecraft data of Io's volcanoes do not meet these criteria, it is particularly important to design future instruments so that they will be able to collect such data. Near-simultaneous data at more than two relatively short wavelengths (shorter than 1 μm) are needed to constrain eruption temperatures. Resolving parts of the lava lake or fountains that are near the eruption temperature is also essential, and we provide a rough estimate of the required image scale.

  6. Estimating eruption temperature from thermal emission spectra of lava fountain activity in the Erta'Ale (Ethiopia) volcano lava lake: Implications for observing Io's volcanoes

    USGS Publications Warehouse

    Davies, A.G.; Keszthelyi, L.; McEwen, A.S.

    2011-01-01

    We have analysed high-spatial-resolution and high-temporal-resolution temperature measurements of the active lava lake at Erta'Ale volcano, Ethiopia, to derive requirements for measuring eruption temperatures at Io's volcanoes. Lava lakes are particularly attractive targets because they are persistent in activity and large, often with ongoing lava fountain activity that exposes lava at near-eruption temperature. Using infrared thermography, we find that extracting useful temperature estimates from remote-sensing data requires (a) high spatial resolution to isolate lava fountains from adjacent cooler lava and (b) rapid acquisition of multi-color data. Because existing spacecraft data of Io's volcanoes do not meet these criteria, it is particularly important to design future instruments so that they will be able to collect such data. Near-simultaneous data at more than two relatively short wavelengths (shorter than 1 ??m) are needed to constrain eruption temperatures. Resolving parts of the lava lake or fountains that are near the eruption temperature is also essential, and we provide a rough estimate of the required image scale. ?? 2011 by the American Geophysical Union.

  7. Estimating eruption temperature from thermal emission spectra of lava fountain activity in the Erta'Ale (Ethiopia) volcano lava lake: Implications for observing Io's volcanoes

    NASA Astrophysics Data System (ADS)

    Davies, Ashley Gerard; Keszthelyi, Laszlo; McEwen, Alfred S.

    2011-11-01

    We have analysed high-spatial-resolution and high-temporal-resolution temperature measurements of the active lava lake at Erta'Ale volcano, Ethiopia, to derive requirements for measuring eruption temperatures at Io's volcanoes. Lava lakes are particularly attractive targets because they are persistent in activity and large, often with ongoing lava fountain activity that exposes lava at near-eruption temperature. Using infrared thermography, we find that extracting useful temperature estimates from remote-sensing data requires (a) high spatial resolution to isolate lava fountains from adjacent cooler lava and (b) rapid acquisition of multi-color data. Because existing spacecraft data of Io's volcanoes do not meet these criteria, it is particularly important to design future instruments so that they will be able to collect such data. Near-simultaneous data at more than two relatively short wavelengths (shorter than 1 μm) are needed to constrain eruption temperatures. Resolving parts of the lava lake or fountains that are near the eruption temperature is also essential, and we provide a rough estimate of the required image scale.

  8. A reconnaissance water-quality appraisal of the Fountain Creek alluvial aquifer between Colorado Springs and Pueblo, Colorado, including trace elements and organic constituents

    USGS Publications Warehouse

    Cain, Doug; Edelmann, Patrick

    1986-01-01

    This report describes the hydrology and chemical quality of water in the stream-aquifer system along Fountain Creek and relates groundwater quality to land use, water use, and wastewater discharges. The alluvial aquifer, which is underlain by shale bedrock, is transmissive, extensively pumped, and primarily is recharged by Fountain Creek and irrigation-return flow. Groundwater flows south about 20 ft/day, average residence time is less than 10 yr. Land use primarily is urban in the northern one-third and agricultural in the southern two-thirds of the area. Major ions, boron, iron, lithium, selenium, strontium, and uranium increased in concentration downgradient. The largest concentrations of nitrogen and detergents were in the northern end of the area because of recharge of sewage effluent in Fountain Creek. Other trace elements usually were present in concentrations less than 20 mg/L. Volatile organic compounds were detected in water from 11 of 20 wells sampled. Samples from 4 of the 20 wells were analyzed for semivolatile organics using a closed-loop stripping technique, which detected additional compounds at nanogram/L concentrations. (USGS)

  9. Reconnaissance water quality appraisal of the Fountain Creek alluvial aquifer between Colorado Springs and Pueblo, Colorado, including trace elements and organic constituents

    SciTech Connect

    Cain, D.; Edelmann, P.

    1986-01-01

    This report describes the hydrology and chemical quality of water in the stream-aquifer system along Fountain Creek and relates groundwater quality to land use, water use, and wastewater discharges. The alluvial aquifer, which is underlain by shale bedrock, is transmissive, extensively pumped, and primarily is recharged by Fountain Creek and irrigation-return flow. Groundwater flows south about 20 ft/day, average residence time is less than 10 yr. Land use primarily is urban in the northern one-third and agricultural in the southern two-thirds of the area. Major ions, boron, iron, lithium, selenium, strontium, and uranium increased in concentration downgradient. The largest concentrations of nitrogen and detergents were in the northern end of the area because of recharge of sewage effluent in Fountain Creek. Other trace elements usually were present in concentrations less than 20 mg/L. Volatile organic compounds were detected in water from 11 of 20 wells sampled. Samples from 4 of the 20 wells were analyzed for semivolatile organics using a closed-loop stripping technique, which detected additional compound at nanogram/L concentrations. 35 refs., 11 figs., 6 tabs.

  10. Computer Code

    NASA Technical Reports Server (NTRS)

    1985-01-01

    COSMIC MINIVER, a computer code developed by NASA for analyzing aerodynamic heating and heat transfer on the Space Shuttle, has been used by Marquardt Company to analyze heat transfer on Navy/Air Force missile bodies. The code analyzes heat transfer by four different methods which can be compared for accuracy. MINIVER saved Marquardt three months in computer time and $15,000.

  11. Association between the clinical classification of hypothyroidism and reduced TSH in LT4 supplemental replacement treatment for pregnancy in China.

    PubMed

    Zhang, Lyu; Zhang, Zhaoyun; Ye, Hongying; Zhu, Xiaoming; Li, Yiming

    2016-05-01

    The study was aimed to evaluate the effects of levothyroxine (LT4) supplemental replacement treatment for pregnancy and analyze the associations between the clinical classification of hypothyroidism and reduced thyroid-stimulating hormone (TSH) in LT4 therapy. Totally, 195 pregnant women with hypothyroidism receiving routine prenatal care were enrolled. They were categorized into three groups: overt hypothyroidism (OH), subclinical hypothyroidism (SCH) with negative thyroperoxidase antibody (TPOAb), and SCH with positive TPOAb. The association between the clinical classification and reduced TSH in LT4 supplemental replacement treatment was assessed. The results indicated that reduced TSH was significantly different among the groups according to the clinical classifications (p = 0.043). The result was also significantly different between patients with OH and patients with SCH and negative TPOAb (p = 0.036). Similar result was reported for the comparison between patients with OH and patients with SCH and positive TPOAb (p = 0.016). Multiple variable analyses showed that LT4 supplementation, gestational age and the variable of clinical classifications were associated with reduced TSH independently. Our data suggested that the therapeutic effect of substitutive treatment with LT4 was significantly associated with different clinical classifications of hypothyroidism in pregnancy and the treatment should begin as soon as possible after diagnosis. PMID:26651855

  12. Polarized Structure Function $\\sigma_{LT'}$ for $p({\\vec e},e'K^+)\\Lambda$ in the Nucleon Resonance Region

    SciTech Connect

    Nasseripour, Rakhsha; Raue, Brian; Ambrozewicz, Pawel; Carman, Daniel; Amaryan, Moscov; Amaryan, Moskov; Anciant, Eric; Anghinolfi, Marco; Asavapibhop, Burin; Asryan, Gegham; Audit, Gerard; Auger, Thierry; Avagyan, Harutyun; Baghdasaryan, Hovhannes; Baillie, Nathan; Ball, J.P.; Ball, Jacques; Ball, J.P.; Ball, Jacques; Ball, J.P.; Ball, Jacques; Ball, J.P.; Ball, Jacques; Baltzell, Nathan; Barrow, Steve; Battaglieri, Marco; Beard, Kevin; Bedlinskiy, Ivan; Bektasoglu, Mehmet; Bellis, Matthew; Benmouna, Nawal; Berman, Barry; Biselli, Angela; Blaszczyk, Lukasz; Bonner, Billy; Bouchigny, Sylvain; Boyarinov, Sergey; Bradford, Robert; Branford, Derek; Briscoe, William; Brooks, William; Burkert, Volker; Butuceanu, Cornel; Calarco, John; Careccia, Sharon; Casey, Liam; Cetina, Catalina; Chen, Shifeng; Cheng, Lu; Cole, Philip; Collins, Patrick; Coltharp, Philip; Cords, Dieter; Corvisiero, Pietro; Crabb, Donald; Crede, Volker; Dale, Daniel; Dashyan, Natalya; De Masi, Rita; De Vita, Raffaella; De Sanctis, Enzo; Degtiarenko, Pavel; Dennis, Lawrence; Deur, Alexandre; Dhuga, Kalvir; Dickson, Richard; Djalali, Chaden; Dodge, Gail; Doughty, David; Dragovitsch, Peter; Dugger, Michael; Dytman, Steven; Dzyubak, Oleksandr; Egiyan, Hovanes; Egiyan, Kim; Elfassi, Lamiaa; Elouadrhiri, Latifa; Eugenio, Paul; Fatemi, Renee; Fedotov, Gleb; Feldman, Gerald; Feuerbach, Robert; Forest, Tony; Fradi, Ahmed; Funsten, Herbert; Garcon, Michel; Gavalian, Gagik; Gevorgyan, Nerses; Gilfoyle, Gerard; Giovanetti, Kevin; Girard, Pascal; Girod, Francois-Xavier; Goetz, John; Gothe, Ralf; Gothe, Ralf; Griffioen, Keith; Guidal, Michel; Guillo, Matthieu; Guler, Nevzat; Guo, Lei; Gyurjyan, Vardan; Hafidi, Kawtar; Hakobyan, Hayk; Hanretty, Charles; Hardie, John; Heddle, David; Hersman, F.; Hicks, Kenneth; Hleiqawi, Ishaq; Holtrop, Maurik; Hu, Jicun; Hyde, Charles; Ilieva, Yordanka; Ireland, David; Ishkhanov, Boris; Isupov, Evgeny; Ito, Mark; Jenkins, David; Jo, Hyon-Suk; Johnstone, John; Joo, Kyungseon; Juengst, Henry; Kalantarians, Narbe; Kellie, James; Khandaker, Mahbubul; Kim, Kui; Kim, Kyungmo; Kim, Wooyoung; Klein, Andreas; Klein, Franz; Kossov, Mikhail; Krahn, Zebulun; Kramer, Laird; Kubarovsky, Valery; Kuhn, Joachim; Kuhn, Sebastian; Kuleshov, Sergey; Kuznetsov, Viacheslav; Lachniet, Jeff; Laget, Jean; Langheinrich, Jorn; Lawrence, David; Livingston, Kenneth; Lu, Haiyun; Lukashin, Konstantin; MacCormick, Marion; Manak, Joseph; Markov, Nikolai; Mattione, Paul; McAleer, Simeon; McKinnon, Bryan; McNabb, John; Mecking, Bernhard; Mestayer, Mac; Meyer, Curtis; Mibe, Tsutomu; Mikhaylov, Konstantin; Minehart, Ralph; Mirazita, Marco; Miskimen, Rory; Mokeev, Viktor; Moreno, Brahim; Moriya, Kei; Morrow, Steven; Moteabbed, Maryam; Mueller, James; Munevar Espitia, Edwin; Mutchler, Gordon; Nadel-Turonski, Pawel; Niccolai, Silvia; Niculescu, Gabriel; Niculescu, Maria-Ioana; Niczyporuk, Bogdan; Niroula, Megh; Niyazov, Rustam; Nozar, Mina; Osipenko, Mikhail; Ostrovidov, Alexander; Park, Kijun; Pasyuk, Evgueni; Paterson, Craig; Pereira, Sergio; Peterson, Gerald; Philips, Sasha; Pierce, Joshua; Pivnyuk, Nikolay; Pocanic, Dinko; Pogorelko, Oleg; Pozdnyakov, Sergey; Preedom, Barry; Price, John; Procureur, Sebastien; Prok, Yelena; Protopopescu, Dan; Qin, Liming; Riccardi, Gregory; Ricco, Giovanni; Ripani, Marco; Ritchie, Barry; Rosner, Guenther; Rossi, Patrizia; Rubin, Philip; Sabatie, Franck; Salamanca, Julian; Salgado, Carlos; Santoro, Joseph; Sapunenko, Vladimir; Sayre, Donald; Schumacher, Reinhard; Serov, Vladimir; Shafi, Aziz; Sharabian, Youri; Sharov, Dmitri; Shvedunov, Nikolay; Simionatto, Sebastio; Skabelin, Alexander; Smith, Elton; Smith, Lee; Sober, Daniel; Sokhan, Daria; Stavinsky, Aleksey; Stepanyan, Samuel; Stepanyan, Stepan; Stokes, Burnham; Stoler, Paul; Strakovski, Igor; Strauch, Steffen; Taiuti, Mauro; Taylor, Shawn; Tedeschi, David; Thoma, Ulrike; Thompson, Richard; Tkabladze, Avtandil; Tkachenko, Svyatoslav; Ungaro, Maurizio; Vineyard, Michael; Vlassov, Alexander; Wang,

    2008-06-01

    The first measurements of the polarized structure function $\\sigma_{LT'}$ for the reaction $p(\\vec e,e'K^+)\\Lambda$ in the nucleon resonance region are reported. Measurements are included from threshold up to $W$=2.05 GeV for central values of $Q^2$ of 0.65 and 1.00 GeV$^2$, and nearly the entire kaon center-of-mass angular range. $\\sigma_{LT'}$ is the imaginary part of the longitudinal-transverse response and is expected to be sensitive to interferences between competing intermediate s-channel resonances, as well as resonant and non-resonant processes. The results for $\\sigma_{LT'}$ are comparable in magnitude to previously reported results from CLAS for $\\sigma_{LT}$, the real part of the same response. An intriguing sign change in $\\sigma_{LT'}$ is observed in the high $Q^2$ data at $W\\approx 1.9$ GeV. Comparisons to several existing model predictions are shown.

  13. Identification of oxygen-rich late/post-asymptotic giant branch stars and water fountains via maser and infrared criteria

    NASA Astrophysics Data System (ADS)

    Yung, Bosco H. K.; Nakashima, Jun-ichi; Henkel, Christian; Hsia, Chih-Hao

    2016-07-01

    The transitional phase between the asymptotic giant branch (AGB) and post-AGB phases holds the key to our understanding of the late-stage metamorphosis of intermediate-mass stars. In particular, high velocity jets forming during this phase are suggested to contribute significantly to the shaping of planetary nebulae. For oxygen-rich stars, the rare “water fountains (WFs)” have been regarded as representative objects in this phase, and it is important to identify more of them for further studies. Here we briefly report the results of our latest OH and H2O maser surveys in which a new WF candidate (IRAS 19356+0754) was found. We also performed radiative transfer modelling on the spectral energy distributions (SEDs) of all known WFs. It is concluded that WFs might in fact not be the transitional objects, as opposed to previous belief. WFs could be AGB or post-AGB stars with no obvious similarities amongst their SEDs. Further efforts are still needed to improve the identification criteria.

  14. HIGH VELOCITY PRECESSING JETS FROM THE WATER FOUNTAIN IRAS 18286-0959 REVEALED BY VERY LONG BASELINE ARRAY OBSERVATIONS

    SciTech Connect

    Yung, Bosco H. K.; Nakashima, Jun-ichi; Kwok, Sun; Imai, Hiroshi; Deguchi, Shuji; Diamond, Philip J.

    2011-11-10

    We report the results of multi-epoch Very Long Baseline Array observations of the 22.2 GHz H{sub 2}O maser emission associated with the 'water fountain' IRAS 18286-0959. We suggest that this object is the second example of a highly collimated bipolar precessing outflow traced by H{sub 2}O maser emission, the other is W 43A. The detected H{sub 2}O emission peaks are distributed over a velocity range from -50 km s{sup -1} to 150 km s{sup -1}. The spatial distribution of over 70% of the identified maser features is found to be highly collimated along a spiral jet (jet 1) extended southeast to northwest; the remaining features appear to trace another spiral jet (jet 2) with a different orientation. The two jets form a 'double-helix' pattern which lies across {approx}200 mas. The maser distribution is reasonably fit by a model consisting of two bipolar precessing jets. The three-dimensional velocities of jet 1 and jet 2 are derived to be 138 km s{sup -1} and 99 km s{sup -1}, respectively. The precession period of jet 1 is about 56 years. For jet 2, three possible models are tested and they give different values for the kinematic parameters. We propose that the appearance of two jets is the result of a single driving source with significant proper motion.

  15. THE HAWAII INFRARED PARALLAX PROGRAM. I. ULTRACOOL BINARIES AND THE L/T TRANSITION

    SciTech Connect

    Dupuy, Trent J.; Liu, Michael C.

    2012-08-01

    We present the first results from our high-precision infrared (IR) astrometry program at the Canada-France-Hawaii Telescope. We measure parallaxes for 83 ultracool dwarfs (spectral types M6-T9) in 49 systems, with a median uncertainty of 1.1 mas (2.3%) and as good as 0.7 mas (0.8%). We provide the first parallaxes for 48 objects in 29 systems, and for another 27 objects in 17 systems, we significantly improve upon published results, with a median (best) improvement of 1.7 times (5 times). Three systems show astrometric perturbations indicative of orbital motion; two are known binaries (2MASS J0518-2828AB and 2MASS J1404-3159AB) and one is spectrally peculiar (SDSS J0805+4812). In addition, we present here a large set of Keck adaptive optics imaging that more than triples the number of binaries with L6-T5 components that have both multi-band photometry and distances. Our data enable an unprecedented look at the photometric properties of brown dwarfs as they cool through the L/T transition. Going from Almost-Equal-To L8 to Almost-Equal-To T4.5, flux in the Y and J bands increases by Almost-Equal-To 0.7 mag and Almost-Equal-To 0.5 mag, respectively (the Y- and J-band 'bumps'), while flux in the H, K, and L' bands declines monotonically. This wavelength dependence is consistent with cloud clearing over a narrow range of temperature, since condensate opacity is expected to dominate at 1.0-1.3 {mu}m. Interestingly, despite more than doubling the near-IR census of L/T transition objects, we find a conspicuous paucity of objects on the color-magnitude diagram just blueward of the late-L/early-T sequence. This 'L/T gap' occurs at (J - H){sub MKO} 0.1-0.3 mag, (J - K){sub MKO} = 0.0-0.4 mag, and implies that the last phases of cloud evolution occur rapidly. Finally, we provide a comprehensive update to the absolute magnitudes of ultracool dwarfs as a function of spectral type using a combined sample of 314 objects.

  16. DNA codes

    SciTech Connect

    Torney, D. C.

    2001-01-01

    We have begun to characterize a variety of codes, motivated by potential implementation as (quaternary) DNA n-sequences, with letters denoted A, C The first codes we studied are the most reminiscent of conventional group codes. For these codes, Hamming similarity was generalized so that the score for matched letters takes more than one value, depending upon which letters are matched [2]. These codes consist of n-sequences satisfying an upper bound on the similarities, summed over the letter positions, of distinct codewords. We chose similarity 2 for matches of letters A and T and 3 for matches of the letters C and G, providing a rough approximation to double-strand bond energies in DNA. An inherent novelty of DNA codes is 'reverse complementation'. The latter may be defined, as follows, not only for alphabets of size four, but, more generally, for any even-size alphabet. All that is required is a matching of the letters of the alphabet: a partition into pairs. Then, the reverse complement of a codeword is obtained by reversing the order of its letters and replacing each letter by its match. For DNA, the matching is AT/CG because these are the Watson-Crick bonding pairs. Reversal arises because two DNA sequences form a double strand with opposite relative orientations. Thus, as will be described in detail, because in vitro decoding involves the formation of double-stranded DNA from two codewords, it is reasonable to assume - for universal applicability - that the reverse complement of any codeword is also a codeword. In particular, self-reverse complementary codewords are expressly forbidden in reverse-complement codes. Thus, an appropriate distance between all pairs of codewords must, when large, effectively prohibit binding between the respective codewords: to form a double strand. Only reverse-complement pairs of codewords should be able to bind. For most applications, a DNA code is to be bi-partitioned, such that the reverse-complementary pairs are separated

  17. Measurement of the polarized structure function sigma_LT^' for pion electroproduction in the Roper-resonance region

    SciTech Connect

    K. Joo; L. C. Smith

    2005-11-01

    The polarized longitudinal-transverse structure function sigma{sub LT'} measures the interference between real and imaginary amplitudes in pion electroproduction and can be used to probe the coupling between resonant and nonresonant processes. We report new measurements of sigma{sub LT'} in the N(1440)1/2+ (Roper) resonance region at Q2=0.40 and 0.65GeV2 for both the pi0p and pi+n channels. The experiment was performed at Jefferson Lab with the CEBAF Large Acceptance Spectrometer (CLAS) using longitudinally polarized electrons at a beam energy of 1.515 GeV. Complete angular distributions were obtained and are compared to recent phenomenological models. The sigma{sub LT'}(pi+n) channel shows a large sensitivity to the Roper-resonance multipoles M1- and S1- and provides new constraints on models of resonance formation.

  18. A direct probe of cloud holes at the L/T transition

    NASA Astrophysics Data System (ADS)

    Buenzli, Esther

    2014-10-01

    Understanding cloud formation, evolution and dispersal is one of the biggest challenges in the field of substellar atmospheres. At the transition from L to T type brown dwarfs, thick silicate and iron clouds disappear below the visible photosphere and the spectra are altered dramatically despite little change in effective temperature. Observed strengthening of the FeH band through the transition has indicated an opening of cloud holes rather than gradual sinking of the clouds. This view has been supported by the discovery of brown dwarfs with photometric variability attributed to patchy cloud cover. However, our recent spectral variability observations have complicated the picture because patchy cloud models with cloud holes currently cannot reproduce the color variations and spectral variability signatures. Whether this implies an absence of cloud holes (in contradiction to the interpretation of the observed strengthening of FeH) or is because models neglect other mechanisms that can affect the colors (eg temperature anomalies) remains unclear. Here, we propose WFC3/G102 spectral variability observations of the very nearby L/T transition benchmark binary Luhman 16AB, the only known variable brown dwarfs in a binary system. These observations target the FeH band. As the FeH molecule contains the cloud forming atom Fe, it is a direct tracer of the cloud holes. By comparing the variability amplitude in the FeH band with the surrounding continuum, as well as between the L and T component at different stages of cloud evolution, we will obtain direct evidence whether the formation of cloud holes is indeed the driving mechanism behind cloud dispersal at the L/T transition.

  19. Mucosal vaccines: non toxic derivatives of LT and CT as mucosal adjuvants.

    PubMed

    Pizza, M; Giuliani, M M; Fontana, M R; Monaci, E; Douce, G; Dougan, G; Mills, K H; Rappuoli, R; Del Giudice, G

    2001-03-21

    Most vaccines are still delivered by injection. Mucosal vaccination would increase compliance and decrease the risk of spread of infectious diseases due to contaminated syringes. However, most vaccines are unable to induce immune responses when administered mucosally, and require the use of strong adjuvant on effective delivery systems. Cholera toxin (CT) and Escherichia coli enterotoxin (LT) are powerful mucosal adjuvants when co-administered with soluble antigens. However, their use in humans is hampered by their extremely high toxicity. During the past few years, site-directed mutagenesis has permitted the generation of LT and CT mutants fully non toxic or with dramatically reduced toxicity, which still retain their strong adjuvanticity at the mucosal level. Among these mutants, are LTK63 (serine-to-lysine substitution at position 63 in the A subunit) and LTR72 (alanine-to-arginine substitution at position 72 in the A subunit). The first is fully non toxic, whereas the latter retains some residual enzymatic activity. Both of them are extremely active as mucosal adjuvants, being able to induce very high titers of antibodies specific for the antigen with which they are co-administered. Both mutants have now been tested as mucosal adjuvants in different animal species using a wide variety of antigens. Interestingly, mucosal delivery (nasal or oral) of antigens together with LTK63 or LTR72 mutants also conferred protection against challenge in appropriate animal models (e.g. tetanus, Helicobacter pylori, pertussis, pneumococci, influenza, etc). In conclusion, these LTK63 and LTR72 mutants are safe adjuvants to enhance the immunogenicity of vaccines at the mucosal level, and will be tested soon in humans. PMID:11257389

  20. [The EDAP LT and the M.P.L. 9000. Results of the treatment of reno-ureteral lithiasis].

    PubMed

    De Cobelli, O; Larcher, P; Carmignani, L; Meroni, T; Franchini, V; Panizzuti, M; Rocco, F

    1989-12-01

    The advantages and disadvantages of piezoelectric lithotripsy are discussed with specific analysis of the EDAP LT 01. A description of the EDAP LT 01 is included. Installation, accommodation, and maintenance features are discussed. The Dornier M.P.L. 9000 represents a third-generation lithotripter for both kidney and gallbladder stones with an ultrasound localization system tubules shock-wave coupling. The use of TH M.P.L. 9000 was limited by ultrasound-guided localization of kidney stones, upper ureteral calculi causing obstruction, and intramural lower ureteral stones. PMID:2532403

  1. Dimorphic HT- and LT-TbTiGe: Electronic and magnetic structures and bonding properties from first principles

    NASA Astrophysics Data System (ADS)

    Matar, Samir F.; Chevalier, Bernard; Etourneau, Jean

    2016-01-01

    TbTiGe intermetallic compound is characterized by temperature dimorphism with different but related crystal structures with ferromagnetic high temperature (HT) form versus antiferromagnetic low temperature (LT) form. Such different structure properties and magnetic behaviors have been addressed based on DFT computations of cohesive energies, charge transfers, mechanical and chemical properties of the two structures. This is particularly illustrated by harder and less ductile LT-form with stronger Ti-Ge bond and larger charge transfer from Tb and Ti on one hand and Ge on the other hand.

  2. The Origin of the Hot Gas in the Galactic Halo: Testing Galactic Fountain Models' X-Ray Emission

    NASA Astrophysics Data System (ADS)

    Henley, David B.; Shelton, Robin L.; Kwak, Kyujin; Hill, Alex S.; Mac Low, Mordecai-Mark

    2015-02-01

    We test the X-ray emission predictions of galactic fountain models against XMM-Newton measurements of the emission from the Milky Way's hot halo. These measurements are from 110 sight lines, spanning the full range of Galactic longitudes. We find that a magnetohydrodynamical simulation of a supernova-driven interstellar medium, which features a flow of hot gas from the disk to the halo, reproduces the temperature but significantly underpredicts the 0.5-2.0 keV surface brightness of the halo (by two orders of magnitude, if we compare the median predicted and observed values). This is true for versions of the model with and without an interstellar magnetic field. We consider different reasons for the discrepancy between the model predictions and the observations. We find that taking into account overionization in cooled halo plasma, which could in principle boost the predicted X-ray emission, is unlikely in practice to bring the predictions in line with the observations. We also find that including thermal conduction, which would tend to increase the surface brightnesses of interfaces between hot and cold gas, would not overcome the surface brightness shortfall. However, charge exchange emission from such interfaces, not included in the current model, may be significant. The faintness of the model may also be due to the lack of cosmic ray driving, meaning that the model may underestimate the amount of material transported from the disk to the halo. In addition, an extended hot halo of accreted material may be important, by supplying hot electrons that could boost the emission of the material driven out from the disk. Additional model predictions are needed to test the relative importance of these processes in explaining the observed halo emission.

  3. Speech coding

    SciTech Connect

    Ravishankar, C., Hughes Network Systems, Germantown, MD

    1998-05-08

    Speech is the predominant means of communication between human beings and since the invention of the telephone by Alexander Graham Bell in 1876, speech services have remained to be the core service in almost all telecommunication systems. Original analog methods of telephony had the disadvantage of speech signal getting corrupted by noise, cross-talk and distortion Long haul transmissions which use repeaters to compensate for the loss in signal strength on transmission links also increase the associated noise and distortion. On the other hand digital transmission is relatively immune to noise, cross-talk and distortion primarily because of the capability to faithfully regenerate digital signal at each repeater purely based on a binary decision. Hence end-to-end performance of the digital link essentially becomes independent of the length and operating frequency bands of the link Hence from a transmission point of view digital transmission has been the preferred approach due to its higher immunity to noise. The need to carry digital speech became extremely important from a service provision point of view as well. Modem requirements have introduced the need for robust, flexible and secure services that can carry a multitude of signal types (such as voice, data and video) without a fundamental change in infrastructure. Such a requirement could not have been easily met without the advent of digital transmission systems, thereby requiring speech to be coded digitally. The term Speech Coding is often referred to techniques that represent or code speech signals either directly as a waveform or as a set of parameters by analyzing the speech signal. In either case, the codes are transmitted to the distant end where speech is reconstructed or synthesized using the received set of codes. A more generic term that is applicable to these techniques that is often interchangeably used with speech coding is the term voice coding. This term is more generic in the sense that the

  4. Evidence of sealing and brine distribution at grain boundaries in natural fine-grained Halite (Qum Kuh salt fountain, Central Iran): implications for rheology of salt extrusions

    NASA Astrophysics Data System (ADS)

    Desbois, Guillaume; Urai, Janos L.; de Bresser, J. H. P.

    2010-05-01

    When grain boundary movement is stopped, surface energy related forces reassert themselves driving the system to its equilibrium conditions ([2], [6], [7], [8]). This could result in growth of islands and shrinking of channels and hence in healing the boundary by internal redistribution of fluid and solid in the contact region. Such islands are proposed to grow preferentially close to the contact rim and promote the healing of the grain-grain contact, which in turn prevents transport in or out the boundary region and thus traps the fluids in isolated inclusions. This contribution is focused on observation of grain boundary microstructures in natural mylonitic rocksalt collected from the distal part of Kum-Quh salt fountain (central Iran) in order to give unprecedented insight of grain boundary microstructures using argon-beam cross-sectioning to prepare high quality polished surfaces suitable for high-resolution SEM imaging. The possibility to use our SEM under cryogenic conditions allows also imaging the in-situ distribution of fluids. Results show that brine at grain boundaries occurs as thick layers (> µm in scale) corresponding to cross-sectioned wetted triple junction tubes, as filling at triple junction and as array of isolated fluids inclusions at grain-grain contacts. Close observations at islands contacts suggest the presence of a very thin fluid film (<100 nm). The most remarkable is evidence for sealing of pore space appearing as subhedral crystals filling the void space and decoupled from surrounding crystals by a thin brine layer. In parallel to this microstructural study, we deformed the same samples in order to simulate the simple shear flow at very low mean stress as in the salt fountain. First results suggest a complicated rheology. Samples loaded at σ < 0.7 MPa show no measurable deformation in a month, indicating strain rates less than 10-12 s-1 though, in fully activated pressure-solution (PS) creep, strain rates of several orders of magnitude

  5. Multi-Stage Tuberculosis Subunit Vaccine Candidate LT69 Provides High Protection against Mycobacterium tuberculosis Infection in Mice

    PubMed Central

    Niu, Hongxia; Peng, Jinxiu; Bai, Chunxiang; Liu, Xun; Hu, Lina; Luo, Yanping; Wang, Bingxiang; Zhang, Ying; Chen, Jianzhu; Yu, Hongjuan; Xian, Qiaoyang; Zhu, Bingdong

    2015-01-01

    Effective tuberculosis (TB) vaccine should target tubercle bacilli with various metabolic states and confer long-term protective immunity. In this study, we constructed a novel multi-stage TB subunit vaccine based on fusion protein ESAT6-Ag85B-MPT64(190-198)-Mtb8.4-HspX (LT69 for short) which combined early expressed antigens and latency-associated antigen. The fusion protein was mixed with an adjuvant being composed of N, N’-dimethyl-N, N’-dioctadecylammonium bromide (DDA) and polyriboinosinic polyribocytidylic acid (PolyI:C) to construct subunit vaccine, whose immunogenicity and protective ability were evaluated in C57BL/6 mice. The results showed that LT69 had strong immunogenicity and high protective effect against Mycobacterium tuberculosis (M. tuberculosis) H37Rv aerosol challenge. Low-dose (2 μg) of LT69 generated long-term immune memory responses and provided effective protection, which was even higher than traditional vaccine BCG did at 30 weeks post the last vaccination. In conclusion, multistage subunit vaccine LT69 showed high and long-term protection against M. tuberculosis infection in mice, whose effect could be enhanced by using a relative low dosage of antigen. PMID:26098302

  6. Production of Escherichia coli heat labile toxin (LT) B subunit in soybean seed and analysis of its immunogenicity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Expression of the heat-labile toxin B subunit of enterotoxigenic Escherichia coli (LT) B was directed to the endoplasmic reticulum (ER) of soybean seed storage parenchyma cells for immunogen sequestration in de novo synthesized, ER-derived protein accretions in transgenic seed. Pentameric LTB accumu...

  7. GUIDANCE MANUAL FOR SOURCE WATER MONITORING UNDER THE LONG-TERM 2 ENHANCED SURFACE WATER TREATMENT RULE (LT2ESWTR)

    EPA Science Inventory

    The manual explains the source water monitoring requirements of LT2ESWTR; provides guidance on how to collect samples for Cryptosporidium and E. coli and on how to establish and manage a Cryptosporidium laboratory contract; and explains how to use and interpret source water monit...

  8. Montelukast rescues primary neurons against Aβ1-42-induced toxicity through inhibiting CysLT1R-mediated NF-κB signaling.

    PubMed

    Lai, Jin'e; Mei, Zhen Lin; Wang, Hao; Hu, Mei; Long, Yan; Miao, Ming Xing; Li, Ning; Hong, Hao

    2014-09-01

    Amyloid-β peptide (Aβ), which can invoke a cascade of inflammatory responses, is considered to play a causal role in the development and progress of Alzheimer's disease (AD). Montelukast, known as a cysteinyl leukotriene receptor 1 (CysLT1R) antagonist, is currently used for treatment of inflammatory diseases such as asthma. We have previously reported that CysLT1R activation is involved in Aβ generation. In this study, we investigated rescuing effect of CysLT1R antagonist montelukast on Aβ1-42-induced neurotoxicity in primary neurons. Our data showed that Aβ1-42 elicited a marked increase of CysLT1R expression in primary mouse neurons. This increment of CysLT1R expression was accompanied by increases of inflammatory factors such as NF-κB p65, tumor necrosis factor-α (TNFα) and interleukin-1β (IL-1β) as well as pro-apoptotic protein Caspase-3 activation and anti-apoptosis protein Bcl-2 reduction. Aβ1-42-mediated increase of CysLT1R expression was associated with Aβ1-42-induced cytotoxicity as measured by MTT reduction assay and lactate dehydrogenase (LDH) release assay. This observation was confirmed with treatment of montelukast, a selective CysLT1R antagonist, which had significant effect on Aβ1-42-induced cytotoxicity. Moreover, blockade of CysLT1R with montelukast reversed Aβ1-42-mediated increase of CysLT1R expression, and concomitant changes of the pro-inflammatory factors and the apoptosis-related proteins. The results demonstrate that montelukast rescued neurons against Aβ1-42-induced neurotoxicity, neuroinflammation and apoptosis by down-regulating CysLT1R-mediated NF-κB signaling, suggesting that CysLT1R may be a potential target for AD, and its antagonist may have beneficial effects for treatment of AD. PMID:24879954

  9. A comparison of ground-based and satellite-derived radiative heat flux at Mt Etna: the 12 August lava fountain case study

    NASA Astrophysics Data System (ADS)

    Ganci, Gaetana; Calvari, Sonia; James, Mike; Del Negro, Ciro

    2013-04-01

    The recent eruptive activity at Mt Etna has been characterized by quiet frequent, intermittent episodes of lava fountains associated with small lava flow output, occurring especially at the SE Crater. During 2011, 18 paroxysmal lava fountains were produced by a new cone, named "Sturiale Cone", on the east flank of the SE Crater. Given the high hazard posed by this activity, and the need of improving detection, description and knowledge of these events, remote monitoring through fixed cameras and satellites has becoming crucial, especially using thermal sensors. We here focus on the 12 August 2011 episode, the strongest of the lava fountains occurred in 2011, and also the best monitored, given the clear sky, absence of clouds, and possibility to collect also images from a close-up view. We disposed of a total of 8 fixed cameras working around the volcano, three of them offering a thermal view of the episode. Moreover, as satellite observations, we could use the complete data set from the SEVIRI sensor, which has a temporal resolution of 15 minutes. To compare the field- and satellite-derived radiative heat flux curves, thermal images were registered by taking into account a DEM, the GPS camera position, the relative camera rotations and first order lens distortion parameters. Moreover, it was performed a pixel by pixel correction from path length and atmospheric effects. Finally, a temperature threshold was fixed to identify the active lava area and the amount of heat lost by radiation from all the pixels covered by lava was computed. SEVIRI data were analyzed by the HOTSAT thermal monitoring system. Through automatic hot-spot detection algorithm based on dynamic thresholds, we are able to provide an estimate of the radiant heat flux for each thermally anomalous pixel and possibly convert it into time averaged discharge rate. Preliminary results showed a good agreement on timing, shape and amplitude of the radiative heat flux time series between thermal camera and

  10. Development of prediction techniques for multi-jet thermal ground flow fields and fountain formation. [generated by V/STOL aircraft

    NASA Technical Reports Server (NTRS)

    Siclari, M. J.; Aidala, P.; Wohllebe, F.; Palcza, J. L.

    1977-01-01

    Avoiding detrimental ground interaction is important for practical V/STOL aircraft. This paper reports recent developments in a numerical method for estimating thermal ground footprints. Upwash and fountain formation for arbitrarily oriented jet arrangements is predicted. Flow asymmetry due to roll, pitch, differential thrust or ground inclination is included. The prediction methodology uses simple inviscid relations for energy and momentum conservation along with an empirical entrainment law, applied in independent sectors of the wall jet and upwash. Asymmetrical stagnation line prediction is compared with experiment. Detailed flow measurements for a three-jet interaction are also presented.

  11. QR Codes

    ERIC Educational Resources Information Center

    Lai, Hsin-Chih; Chang, Chun-Yen; Li, Wen-Shiane; Fan, Yu-Lin; Wu, Ying-Tien

    2013-01-01

    This study presents an m-learning method that incorporates Integrated Quick Response (QR) codes. This learning method not only achieves the objectives of outdoor education, but it also increases applications of Cognitive Theory of Multimedia Learning (CTML) (Mayer, 2001) in m-learning for practical use in a diverse range of outdoor locations. When…

  12. Ectopic LT alpha beta directs lymphoid organ neogenesis with concomitant expression of peripheral node addressin and a HEV-restricted sulfotransferase.

    PubMed

    Drayton, Danielle L; Ying, Xiaoyan; Lee, Jason; Lesslauer, Werner; Ruddle, Nancy H

    2003-05-01

    Lymph node (LN) function depends on T and B cell compartmentalization, antigen presenting cells, and high endothelial venules (HEVs) expressing mucosal addressin cell adhesion molecule (MAdCAM-1) and peripheral node addressin (PNAd), ligands for naive cell entrance into LNs. Luminal PNAd expression requires a HEV-restricted sulfotransferase (HEC-6ST). To investigate LT alpha beta's activities in lymphoid organogenesis, mice simultaneously expressing LT alpha and LT beta under rat insulin promoter II (RIP) control were compared with RIPLT alpha mice in a model of lymphoid neogenesis and with LT beta-/- mice. RIPLT alpha beta pancreata exhibited massive intra-islet mononuclear infiltrates that differed from the more sparse peri-islet cell accumulations in RIPLT alpha pancreata: separation into T and B cell areas was more distinct with prominent FDC networks, expression of lymphoid chemokines (CCL21, CCL19, and CXCL13) was more intense, and L-selectin+ cells were more frequent. In contrast to the predominant abluminal PNAd pattern of HEV in LT beta-/- MLN and RIPLT alpha pancreatic infiltrates, PNAd was expressed at the luminal and abluminal aspects of HEV in wild-type LN and in RIPLT alpha beta pancreata, coincident with HEC-6ST. These data highlight distinct roles of LT alpha and LT alpha beta in lymphoid organogenesis supporting the notion that HEC-6ST-dependent luminal PNAd is under regulation by LT alpha beta. PMID:12732657

  13. Modification of the GS LT Paired-end Library Protocol for Constructing Longer Insert Size Libraries

    SciTech Connect

    Peng, Ze; Peng, Ze; Hamilton, Matthew; Ting, Sara; Tu, Hank; Goltsman, Eugene; Lapidus, Alla; Lucas, Susan; Cheng, Jan-Fang

    2008-05-22

    Paired-end library sequencing has been proven useful in scaffold construction during de novo assembly of genomic sequences. The ability of generating mate pairs with 8 Kb or greater insert sizes is especially important for genomes containing long repeats. While the current 454 GS LT Paired-end library preparation protocol can successfully construct libraries with 3 Kb insert size, it fails to generate longer insert sizes because the protocol is optimized to purify shorter fragments. We have made several changes in the protocol in order to increase the fragment length. These changes include the use of Promega column to increase the yield of large size DNA fragments, two gel purification steps to remove contaminated short fragments, and a large reaction volume in the circularization step to decrease the formation of chimeras. We have also made additional changes in the protocol to increase the overall quality of the libraries. The quality of the libraries are measured by a set of metrics, which include levels of redundant reads, linker positive, linker negative, half linker reads, and driver DNA contamination, and read length distribution, were used to measure the primary quality of these libraries. We have also assessed the quality of the resulted mate pairs including levels of chimera, distribution of insert sizes, and genome coverage after the assemblies are completed. Our data indicated that all these changes have improved the quality of the longer insert size libraries.

  14. Low Q2 Measurement of g2p and the LT Spin Polarizability

    SciTech Connect

    Karl Slifer

    2009-07-01

    JLab has been at the forefront of a program to measure the nucleon spin-dependent structure functions over a wide kinematic range, and data of unprecedented quality has been extracted in all three experimental halls. Moments of these quantities have proven to be powerful tools to test QCD sum rules and provide benchmark tests of Lattice QCD and Chiral Perturbation Theory. Precision measurements of $g_{1,2}^n$ and $g_1^p$ have been performed as part of the highly successful `extended GDH program', but data on the $g_2^p$ structure function remain scarce. We discuss here JLab experiment E08-027, which will measure quantity $g_2^p$ in the resonance region at low $Q^2$. These data will be used to test the Burkhardt-Cottingham sum rule and to extract the higher moments $\\delta_{LT}^p(Q^2)$ and $\\overline{d}_2^p(Q^2)$. Data in the $Q^2$ range $0.02

  15. An atlas of L-T transition brown dwarfs with VLT/XShooter

    NASA Astrophysics Data System (ADS)

    Marocco, F.; Day-Jones, A. C.; Jones, H. R. A.; Pinfield, D. J.

    In this contribution we present the first results from a large observing campaign we are carrying out using VLT/Xshooter to obtain spectra of a large sample (˜250 objects) of L-T transition brown dwarfs. Here we report the results based on the first ˜120 spectra already obtained. The large sample, and the wide spectral coverage (300-2480 nm) given by Xshooter, will allow us to do a new powerful analysis, at an unprecedent level. By fitting the absorption lines of a given element (e.g. Na) at different wavelengths we can test ultracool atmospheric models and draw for the first time a 3D picture of stellar atmospheres at temperatures down to 1000K. Determining the atmospheric parameters (e.g. temperature, surface gravity and metallicity) of a big sample of brown dwarfs, will allow us to understand the role of these parameters on the formation of their spectra. The large number of objects in our sample also will allow us to do a statistical significant test of the birth rate and initial mass function predictions for brown dwarfs. Determining the shape of the initial mass function for very low mass objects is a fundamental task to improve galaxy models, as recent studies tep{2010Natur.468..940V} have shown that low-mass objects dominate in massive elliptical galaxies.

  16. Challenges and Advances in Instrumentation of UHV LT Multi-Probe SPM System

    NASA Astrophysics Data System (ADS)

    Wang, Zhouhang

    The progress of nanoscience and nanotechnology can be realized only through continued advances and utilization of instruments and techniques for characterizing material properties and manipulating material and device at nanoscale. The UHV LT Multi-Probe SPM system with high resolution SEM has been developed to meet such challenges. This integrated instrument bridges dimensions from the centimeter to atomic scale, and provides an unprecedented platform for local, non-destructive transport measurements and for building, manipulating and function-testing complex nanoelectronics and nanoscale machineries. It also enables combining many different techniques for characterizing sample conductance, topography, chemical, optical or magnetic properties with complementary information at the same position or on the same nanodevice. Design and development of such complex systems pose many issues and challenges. This chapter will discuss some of the issues faced, solutions reached and advances made. Examples include: (1) Disturbance by magnetic material and magnetic field of SEM imaging and coordination of SEM/SPM position, and their influence on and disturbance of SAM spectra and SAM mapping. The design and use of non-magnetic motors for multi-probe modules will be presented and discussed. (2) Tip holder and sample holder design for easy handling, better mechanical stability over the temperature range and better thermal contact and the versatility of the sample holder with multiple contacts. (3) Use of optical fiber as one of the probe modules, and positioning of the fiber probe. CL spectra and CL mapping results will be presented.

  17. Characterization and analysis of temporal and spatial variations in habitat and macroinvertebrate community structure, Fountain Creek basin, Colorado Springs and vicinity, Colorado, 1998-2001

    USGS Publications Warehouse

    Bruce, James F.

    2002-01-01

    The Fountain Creek Basin in and around Colorado Springs, Colorado, is affected by various land- and water-use activities. Biological, hydrological, water-quality, and land-use data were collected at 10 sites in the Fountain Creek Basin from April 1998 through April 2001 to provide a baseline characterization of macroinvertebrate communities and habitat conditions for comparison in subsequent studies; and to assess variation in macroinvertebrate community structure relative to habitat quality. Analysis of variance results indicated that instream and riparian variables were not affected by season, but significant differences were found among sites. Nine metrics were used to describe and evaluate macroinvertebrate community structure. Statistical analysis indicated that for six of the nine metrics, significant variability occurred between spring and fall seasons for 60 percent of the sites. Cluster analysis (unweighted pair group method average) using macroinvertebrate presence-absence data showed a well-defined separation between spring and fall samples. Six of the nine metrics had significant spatial variation. Cluster analysis using Sorenson?s Coefficient of Community values computed from macroinvertebrate density (number of organisms per square meter) data showed that macroinvertebrate community structure was more similar among tributary sites than main-stem sites. Canonical correspondence analysis identified a substrate particle-size gradient from site-specific species-abundance data and environmental correlates that decreased the 10 sites to 5 site clusters and their associated taxa.

  18. Characterization of Stormflows and Wastewater Treatment-Plant Effluent Discharges on Water Quality, Suspended Sediment, and Stream Morphology for Fountain and Monument Creek Watersheds, Colorado, 1981-2006

    USGS Publications Warehouse

    Mau, David P.; Stogner, Robert W.; Edelmann, Patrick

    2007-01-01

    In 1998, the U.S. Geological Survey, in cooperation with Colorado Springs City Engineering, began a study of the Fountain and Monument Creek watersheds to characterize water quality and suspended-sediment conditions in the watershed for different flow regimes, with an emphasis on characterizing water quality during storm runoff. Water-quality and suspended-sediment samples were collected in the Fountain and Monument Creek watersheds from 1981 through 2006 to evaluate the effects of stormflows and wastewater-treatment effluent on Fountain and Monument Creeks in the Colorado Springs, Colorado, area. Water-quality data were collected at 11 sites between 1981 and 2001, and 14 tributary sites were added in 2003 to increase spatial coverage and characterize water quality throughout the watersheds. Suspended-sediment samples collected daily at 7 sites from 1998 through 2001, 6 sites daily from 2003 through 2006, and 13 tributary sites intermittently from 2003 through 2006 were used to evaluate the effects of stormflow on suspended-sediment concentrations, discharges, and yields. Data were separated into three flow regimes: base flow, normal flow, and stormflow. Stormflow concentrations from 1998 through 2006 were compared to Colorado acute instream standards and, with the exception of a few isolated cases, did not exceed water-quality standards for inorganic constituents that were analyzed. However, stormflow concentrations of both fecal coliform and Escherichia coli (E. coli) frequently exceeded water-quality standards during 1998 through 2006 on main-stem and tributary sites by more than an order of magnitude. There were two sites on Cottonwood Creek, a tributary to Monument Creek, with elevated concentrations of dissolved nitrite plus nitrate: site 07103985 (TbCr), a tributary to Cottonwood Creek and site 07103990 (lower_CoCr), downstream from site 07103985 (TbCr), and near the confluence with Monument Creek. During base-flow and normal-flow conditions, the median

  19. HST SPECTRAL MAPPING OF L/T TRANSITION BROWN DWARFS REVEALS CLOUD THICKNESS VARIATIONS

    SciTech Connect

    Apai, Daniel; Radigan, Jacqueline; Jayawardhana, Ray; Buenzli, Esther; Burrows, Adam; Reid, Iain Neill

    2013-05-10

    Most directly imaged giant exoplanets are fainter than brown dwarfs with similar spectra. To explain their relative underluminosity, unusually cloudy atmospheres have been proposed. However, with multiple parameters varying between any two objects, it remained difficult to observationally test this idea. We present a new method, sensitive time-resolved Hubble Space Telescope near-infrared spectroscopy, to study two rotating L/T transition brown dwarfs (2M2139 and SIMP0136). The observations provide spatially and spectrally resolved mapping of the cloud decks of the brown dwarfs. The data allow the study of cloud structure variations while other parameters are unchanged. We find that both brown dwarfs display variations of identical nature: J- and H-band brightness variations with minimal color and spectral changes. Our light curve models show that even the simplest surface brightness distributions require at least three elliptical spots. We show that for each source the spectral changes can be reproduced with a linear combination of only two different spectra, i.e., the entire surface is covered by two distinct types of regions. Modeling the color changes and spectral variations together reveal patchy cloud covers consisting of a spatially heterogeneous mix of low-brightness, low-temperature thick clouds and brighter, thin, and warm clouds. We show that the same thick cloud patches seen in our varying brown dwarf targets, if extended to the entire photosphere, predict near-infrared colors/magnitudes matching the range occupied by the directly imaged exoplanets that are cooler and less luminous than brown dwarfs with similar spectral types. This supports the models in which thick clouds are responsible for the near-infrared properties of these ''underluminous'' exoplanets.

  20. Sub-Inhibitory Fosmidomycin Exposures Elicits Oxidative Stress in Salmonella enterica Serovar typhimurium LT2

    PubMed Central

    Fox, David T.; Schmidt, Emily N.; Tian, Hongzhao; Dhungana, Suraj; Valentine, Michael C.; Warrington, Nicole V.; Phillips, Paul D.; Finney, Kellan B.; Cope, Emily K.; Leid, Jeff G.; Testa, Charles A.; Koppisch, Andrew T.

    2014-01-01

    Fosmidomycin is a time-dependent nanomolar inhibitor of methylerythritol phosphate (MEP) synthase, which is the enzyme that catalyzes the first committed step in the MEP pathway to isoprenoids. Importantly, fosmidomycin is one of only a few MEP pathway-specific inhibitors that exhibits antimicrobial activity. Most inhibitors identified to date only exhibit activity against isolated pathway enzymes. The MEP pathway is the sole route to isoprenoids in many bacteria, yet has no human homologs. The development of inhibitors of this pathway holds promise as novel antimicrobial agents. Similarly, analyses of the bacterial response toward MEP pathway inhibitors provides valuable information toward the understanding of how emergent resistance may ultimately develop to this class of antibiotics. We have examined the transcriptional response of Salmonella enterica serovar typhimurium LT2 to sub-inhibitory concentrations of fosmidomycin via cDNA microarray and RT-PCR. Within the regulated genes identified by microarray were a number of genes encoding enzymes associated with the mediation of reactive oxygen species (ROS). Regulation of a panel of genes implicated in the response of cells to oxidative stress (including genes for catalases, superoxide dismutases, and alkylhydrogen peroxide reductases) was investigated and mild upregulation in some members was observed as a function of fosmidomycin exposure over time. The extent of regulation of these genes was similar to that observed for comparable exposures to kanamycin, but differed significantly from tetracycline. Furthermore, S. typhimurium exposed to sub-inhibitory concentrations of fosmidomycin displayed an increased sensitivity to exogenous H2O2 relative to either untreated controls or kanamycin-treated cells. Our results suggest that endogenous oxidative stress is one consequence of exposures to fosmidomycin, likely through the temporal depletion of intracellular isoprenoids themselves, rather than other mechanisms that

  1. New insight into the structure of saturated chlorine layer on Ag(1 1 1): LT-STM and DFT study

    NASA Astrophysics Data System (ADS)

    Andryushechkin, B. V.; Cherkez, V. V.; Gladchenko, E. V.; Zhidomirov, G. M.; Kierren, B.; Fagot-Revurat, Y.; Malterre, D.; Eltsov, K. N.

    2013-02-01

    Atomic structures formed on the Ag(1 1 1) surface as a result of molecular chlorine adsorption have been studied with a low-temperature scanning tunneling microscopy (LT-STM) in a combination with DFT calculations. We have found that saturated chlorine coverage on Ag(1 1 1) is a complex system consisting of two different structural phases: small anti-phase domains of a (3 × 3) reconstruction and nanoclusters Ag3Cl7.

  2. An In Silico Insight into Novel Therapeutic Interaction of LTNF Peptide-LT10 and Design of Structure Based Peptidomimetics for Putative Anti-Diabetic Activity

    PubMed Central

    Chavan, Sonali Gopichand; Deobagkar, Deepti Dileep

    2015-01-01

    Lethal Toxin Neutralizing Factor (LTNF) obtained from Opossum serum (Didephis virginiana) is known to exhibit toxin-neutralizing activity for envenomation caused by animals, plants and bacteria. Small synthetic peptide- LT10 (10mer) derived from N-terminal fraction of LTNF exhibit similar anti-lethal and anti-allergic property. In our in silico study, we identified Insulin Degrading Enzyme (IDE) as a potential target of LT10 peptide followed by molecular docking and molecular dynamic (MD) simulation studies which revealed relatively stable interaction of LT10 peptide with IDE. Moreover, their detailed interaction analyses dictate IDE-inhibitory interactions of LT10 peptide. This prediction ofLT10 peptide as a novel putative IDE-inhibitor suggests its possible role in anti-diabetic treatment since IDE- inhibitors are known to assist treatment of Diabetes mellitus by enhancing insulin signalling. Furthermore, series of structure based peptidomimetics were designed from LT10 peptide and screened for their inhibitory interactions which ultimately led to a small set of peptidomimetic inhibitors of IDE. These peptidomimetic thus might provide a new class of IDE-inhibitors, those derived from LT10 peptide. PMID:25816209

  3. Laser Soap Fountain

    ERIC Educational Resources Information Center

    Foley, Tyler; Pegram, Matthew; Jenkins, Zachary; Hester, Brooke C.; Burris, Jennifer L.

    2015-01-01

    We have developed an eye-catching demonstration that showcases a variety of physics topics from total internal reflection to electrostatics to non-Newtonian fluid dynamics, including the Kaye effect. The essential components of the demonstration include a vertical stream of liquid soap in which a laser pointer is internally reflected, and which…

  4. Development of a high-performance composite cathode for LT-SOFC

    NASA Astrophysics Data System (ADS)

    Lee, Byung Wook

    Solid Oxide Fuel Cell (SOFC) has drawn considerable attention for decades due to its high efficiency and low pollution, which is made possible since chemical energy is directly converted to electrical energy through the system without combustion. However, successful commercialization of SOFC has been delayed due to its high production cost mainly related with using high cost of interconnecting materials and the other structural components required for high temperature operation. This is the reason that intermediate (IT) or low temperature (LT)-SOFC operating at 600~800°C or 650°C and below, respectively, is of particular significance because it allows the wider selection of cheaper materials such as stainless steel for interconnects and the other structural components. Also, extended lifetime and system reliability are expected due to less thermal stress through the system with reduced temperature. More rapid start-up/shut-down procedure is another advantage of lowering the operating temperatures. As a result, commercialization of SOFC will be more viable. However, there exists performance drop with reduced operating temperature due to increased polarization resistances from the electrode electrochemical reactions and decreased electrolyte conductivity. Since ohmic polarization of the electrolyte can be significantly reduced with state-of-the art thin film technology and cathode polarization has more drastic effect on total SOFC electrochemical performance than anode polarization as temperature decreases, development of the cathode with high performance operating at IT or LT range is thus essential. On the other hand, chemical stability of the cathode and its chemical compatibility with the electrolyte should also be considered for cathode development since instability and incompatibility of the cathode will also cause substantial performance loss. Based on requirements of the cathode mentioned above, in this study, several chemico-physical approaches were

  5. Complex fragmentation and silicification structures in fault zones: quartz mineralization and repeated fragmentation along the Fountain Range Fault (Mt. Isa Inlier, Australia)

    NASA Astrophysics Data System (ADS)

    Seybold, Lina; Blenkinsop, Tom; Heuss, Soraya; Ord, Alison; Kruhl, Jörn H.

    2015-04-01

    In large-scale fault zones fracture networks are commonly generated by high volumes of pressurized fluids, followed by quartz precipitation. In this way large amounts of quartz are formed as microcrystalline masses and as complex vein systems, with partly highly different textures, as a result of different formation processes. Based on field and microstructural data and the quantification of vein patterns, the spatial and temporal connection between fragmentation, quartz crystallization and fluid and material flow along the Fountain Range Fault at Fountain Springs was investigated. Dextral strike-slip led to up to 25 km horizontal displacement along the fault. Due to various fragmentation and quartz formation processes, a ca. 100 m high, 80 - 100 m wide and km-long quartz ridge with numerous vein systems and variable microfabrics was formed. Locally, lenses of highly altered metamorphic wall-rocks occur in the quartz zone. Where exposed, the contact to wall rocks is sharp. Millimetre- to decimetre-thick quartz veins penetrate the wall-rocks only within metre distance from the contact. Several clearly distinguishable fine-grained reddish, brownish to dark and pigment-rich quartz masses form up to 50 m wide and up to several 100 m long steep lenses that build the major part of the silicified fault zone. A chronology can be established. Some of these lenses are oriented slightly oblique to the general trend of the quartz zone, in agreement with the supposed dextral strike slip along the fault. Numerous generations of typically µm-cm thick quartz veins transect the microcrystalline quartz masses and, locally, form anisotropic networks. In the quartz masses, angular fragments often composed of quartz with, again, internal fragmentation structures, indicate earlier fracturing and silicification events. Within the veins, quartz forms geodes, locally filled with fine-grained reddish quartz and palisade structures with feathery textures and fluid-inclusion zoning

  6. Evidence of a shallow persistent magmatic reservoir from joint inversion of gravity and ground deformation data: The 25-26 October 2013 Etna lava fountaining event

    NASA Astrophysics Data System (ADS)

    Greco, Filippo; Currenti, Gilda; Palano, Mimmo; Pepe, Antonio; Pepe, Susi

    2016-04-01

    To evaluate the volcanic processes leading to the 25-26 October 2013 lava fountain at Mount Etna, we jointly investigated gravity, GPS, and DInSAR measurements covering the late-June to early-November time interval. We used finite element modeling to infer a shallow magmatic reservoir which (i) inflated since July 2013, (ii) fed the volcanic activity at the summit craters during 25-26 October, and (iii) deflated due to magma drainage related to this volcanic activity. We suggested that this reservoir belongs to a shallow volume, which is located beneath the summit area and is replenished by magma rising from deep reservoirs and fed the short-term volcanic activity, representing a persistent shallow magmatic plumbing system of Etna. In addition, the model results show that there is a large discrepancy between the erupted and shallow reservoir deflation volumes, which could be reasonably attributable to a highly compressible volatile-rich magma.

  7. Simulations of the Cleft Ion Fountain outflows resulting from the passage of Storm Enhanced Density (SED) plasma flux tubes through the dayside cleft auroral processes region

    NASA Astrophysics Data System (ADS)

    Horwitz, James; Zeng, Wen

    2007-10-01

    Foster et al. [2002] reported elevated ionospheric density regions convected from subauroral plasmaspheric regions toward noon, in association with convection of plasmaspheric tails. These Storm Enhanced Density (SED) regions could supply cleft ion fountain outflows. Here, we will utilize our Dynamic Fluid Kinetic (DyFK) model to simulate the entry of a high-density ``plasmasphere-like'' flux tube entering the cleft region and subjected to an episode of wave-driven transverse ion heating. It is found that the O^+ ion density at higher altitudes increases and the density at lower altitudes decreases, following this heating episode, indicating increased fluxes of O^+ ions from the ionospheric source gain sufficient energy to reach higher altitudes after the effects of transverse wave heating. Foster, J. C., P. J. Erickson, A. J. Coster, J. Goldstein, and F. J. Rich, Ionospheric signatures of plasmaspheric tails, Geophys. Res. Lett., 29(13), 1623, doi:10.1029/2002GL015067, 2002.

  8. Codes with special correlation.

    NASA Technical Reports Server (NTRS)

    Baumert, L. D.

    1964-01-01

    Uniform binary codes with special correlation including transorthogonality and simplex code, Hadamard matrices and difference sets uniform binary codes with special correlation including transorthogonality and simplex code, Hadamard matrices and difference sets

  9. PM10 measurements in urban settlements after lava fountain episodes at Mt Etna, Italy: pilot test to assess volcanic ash hazard on human health

    NASA Astrophysics Data System (ADS)

    Andronico, D.; Del Carlo, P.

    2015-06-01

    In this paper we focus on the potential risks caused by the sub-10 micron fraction of volcanic ash (particulate matter: PM10) after the basaltic explosive eruptions from Mt Etna volcano (Italy), which have dramatically increased in frequency over the last 20 years. We present results deriving from the study of the ash concentration in the air following the lava fountain episode from the New South-East Crater of Etna on 15 November 2011, which caused tephra fallout over the eastern slope of the volcano. Short-duration tests of PM10 measurements were carried out at three different sites using a TSI® DustTrakTM aerosol monitor a few hours after the end of the eruption, and readouts of the air quality were repeated at the same sites a month later without volcanic activity. Furthermore, ash samples were characterized by grain-size, componentry, morphological and petro-chemical analyses. By comparing PM10 levels measured a few hours after the 15 November lava fountain and on 15 December, we found that relatively low amounts (500-1500 g m-2) of tephra fallout cause high levels of PM10 in the air. This is because the coarse particles, like basaltic ash, are readily broken up by traffic and hence remobilized into the air, due to their intrinsic, physical and morphological features. We believe that in the future the impact from ash fallout in the Etnean territory should receive proper attention in order to avoid potential health problems; this may be achieved by accomplishing simple but effective actions, first and foremost the prompt removal of the ash deposits from the urbanized areas.

  10. PM10 measurements in urban settlements after lava fountain episodes at Mt. Etna, Italy: pilot test to assess volcanic ash hazard to human health

    NASA Astrophysics Data System (ADS)

    Andronico, D.; Del Carlo, P.

    2016-01-01

    We have carried out a preliminary study on the potential risks caused by the sub-10 µm fraction of volcanic ash (particulate matter, PM10) after the basaltic explosive eruptions from Mt. Etna volcano (Italy), which have dramatically increased in frequency over the last 20 years. We present results deriving from the study of the ash concentration in the air following the lava fountain episode from the New Southeast Crater of Etna on 15 November 2011, which caused tephra fallout over the eastern slope of the volcano. Short-duration tests of PM10 measurements were carried out at three different sites using a TSI® DustTrakTM aerosol monitor a few hours after the end of the eruption, and readouts of the air quality were repeated at the same sites a month later without volcanic activity. Furthermore, ash samples were characterized by grain size, componentry and morphological and petrochemical analyses. By comparing PM10 levels measured a few hours after the 15 November lava fountain and on 15 December, we found that relatively low amounts (500-1500 g m-2) of tephra fallout cause high levels of PM10 in the air. This is because the coarse particles, particularly basaltic ash, are readily broken up by traffic and hence remobilized into the air. We believe the impact from ash fallout in the Etnean territory should receive greater attention, especially regarding potential health problems. Simple but effective actions can be implemented to reduce eventual risks, first and foremost the prompt removal of the ash deposits from the urbanized areas.

  11. Sediment-transport characteristics and effects of sediment transport on benthic invertebrates in the Fountain Creek drainage basin upstream from Widefield, southeastern Colorado, 1985-88

    USGS Publications Warehouse

    Von Guerard, Paul

    1989-01-01

    Sediment and benthic-invertebrate data were collected during water years 1985 through 1988 in the Fountain Creek drainage basin upstream from Widefield, Colorado. Sediment data collected include suspended-sediment concentrations and particle size analysis of suspended sediment, bedload, and bed material. Sediment-transport equations were derived for total suspended-sediment discharge and suspended-sand discharge at seven periodic sampling sites. Annual suspended-sediment loads for water years 1985 through 1988 and mean suspended-sediment yields were computed for the seven periodic sampling sites. Mean annual suspended-sediment yield for 1985 through 1988 increased about 73% downstream in the Fountain Creek drainage basin primarily as a result of sediment discharging from Monument Creek. Bedload discharge was computed at six of the periodic sampling sites and ranged from 2.6 to 3,570 tons/day. Bedload discharge, as a percentage of total sediment discharge, ranged from 6 to 92%, and the smaller values occurred during rainfall runoff. Number of taxa, species density, and similarity indices were determined for benthic invertebrates at five of the periodic sampling sites. Multiple comparison tests were used to test for similarity of benthic invertebrates between the five sites. Multiple-regression analysis was done to determine the effects of sediment transport on benthic-invertebrate densities. Median grain size of bed material collected in conjunction with benthic- invertebrate samples and flooding during the 30 days prior to sampling consistently accounted for the most variation in mean densities of total organisms and major taxa groups sampled. (USGS)

  12. 6-Shogaol has anti-amyloidogenic activity and ameliorates Alzheimer's disease via CysLT1R-mediated inhibition of cathepsin B.

    PubMed

    Na, Ji-Young; Song, Kibbeum; Lee, Ju-Woon; Kim, Sokho; Kwon, Jungkee

    2016-08-12

    Although 6-shogaol, a constituent of ginger, has been reported to have anti-inflammatory and anti-oxidant effects on neuronal cells, the effects of 6-shogaol on Alzheimer's disease (AD) have not yet been investigated. Here we aimed to determine whether 6-shogaol exerts neuroprotective effects against AD. Specifically, we investigated the effects of 6-shogaol on the cysteinyl leukotriene 1 receptor (CysLT1R), a major factor in AD pathogenesis. Moreover, we clarified the relationship between CysLT1R and cathepsin B, a cysteine protease. We used in vitro and in vivo models to determine whether 6-shogaol inhibits CysLT1R/cathepsin B in an amyloid-beta (Aβ; 1-42)-induced model of neurotoxicity. We first confirmed that CysLT1R and cathepsin B are upregulated by Aβ (1-42) and that CysLT1R activation induces cathepsin B. In contrast, we found that 6-shogaol-mediated inhibition of CysLT1R downregulates cathepsin B in both in vitro and in vivo models. Furthermore, we found that 6-shogaol-mediated inhibition of CysLT1R/cathepsin B reduces Aβ deposition in the brain and ameliorates behavioral deficits in APPSw/PS1-dE9 Tg mice. Our results indicate that 6-shogaol is a CysLT1R/cathepsin B inhibitor and is a novel potential therapeutic agent for the treatment of various neurodegenerative diseases, including AD. PMID:27286707

  13. Atypical α-Conotoxin LtIA from Conus litteratus Targets a Novel Microsite of the α3β2 Nicotinic Receptor*

    PubMed Central

    Luo, Sulan; Akondi, Kalyana Bharati; Zhangsun, Dongting; Wu, Yong; Zhu, Xiaopeng; Hu, Yuanyan; Christensen, Sean; Dowell, Cheryl; Daly, Norelle L.; Craik, David J.; Wang, Ching-I. Anderson; Lewis, Richard J.; Alewood, Paul F.; Michael McIntosh, J.

    2010-01-01

    Different nicotinic acetylcholine receptor (nAChR) subtypes are implicated in learning, pain sensation, and disease states, including Parkinson disease and nicotine addiction. α-Conotoxins are among the most selective nAChR ligands. Mechanistic insights into the structure, function, and receptor interaction of α-conotoxins may serve as a platform for development of new therapies. Previously characterized α-conotoxins have a highly conserved Ser-Xaa-Pro motif that is crucial for potent nAChR interaction. This study characterized the novel α-conotoxin LtIA, which lacks this highly conserved motif but potently blocked α3β2 nAChRs with a 9.8 nm IC50 value. The off-rate of LtIA was rapid relative to Ser-Xaa-Pro-containing α-conotoxin MII. Nevertheless, pre-block of α3β2 nAChRs with LtIA prevented the slowly reversible block associated with MII, suggesting overlap in their binding sites. nAChR β subunit ligand-binding interface mutations were used to examine the >1000-fold selectivity difference of LtIA for α3β2 versus α3β4 nAChRs. Unlike MII, LtIA had a >900-fold increased IC50 value on α3β2(F119Q) versus wild type nAChRs, whereas T59K and V111I β2 mutants had little effect. Molecular docking simulations suggested that LtIA had a surprisingly shallow binding site on the α3β2 nAChR that includes β2 Lys-79. The K79A mutant disrupted LtIA binding but was without effect on an LtIA analog where the Ser-Xaa-Pro motif is present, consistent with distinct binding modes. PMID:20145249

  14. Error-correction coding

    NASA Technical Reports Server (NTRS)

    Hinds, Erold W. (Principal Investigator)

    1996-01-01

    This report describes the progress made towards the completion of a specific task on error-correcting coding. The proposed research consisted of investigating the use of modulation block codes as the inner code of a concatenated coding system in order to improve the overall space link communications performance. The study proposed to identify and analyze candidate codes that will complement the performance of the overall coding system which uses the interleaved RS (255,223) code as the outer code.

  15. Enhancement of humoral immunity by the type II heat-labile enterotoxin LT-IIb is dependent upon IL-6 and neutrophils.

    PubMed

    Greene, Christopher J; Hu, John C; Vance, David J; Rong, Yinghui; Mandell, Lorrie; King-Lyons, Natalie; Masso-Welch, Patricia; Mantis, Nicholas J; Connell, Terry D

    2016-08-01

    LT-IIb, a type II heat-labile enterotoxin produced by Escherichia coli, is a potent intradermal adjuvant that enhances immune responses to coadministered antigens. Although the immune mechanisms that promote this augmented immune response have not been well defined, prior intradermal immunization experiments suggested that early cellular and immunomodulatory events at the site of immunization modulated the augmentation of antigen-specific immune responses by LT-IIb. To investigate that hypothesis, mice were intradermally immunized with a recombinant ricin vaccine, a prospective toxin subunit antigen, in the presence and absence of LT-IIb. Analysis of tissue-fluid collection, coupled with histologic sections from the site of intradermal immunization, revealed that a single dose of LT-IIb induced local production of interleukin 6 and promoted a regional infiltration of neutrophils. The adjuvant effects of LT-IIb were abrogated in interleukin 6-deficient mice and when mice were depleted of neutrophils by pretreatment with anti-Ly6G. Overall, these data firmly demonstrated that LT-IIb, when used as an intradermal adjuvant, recruits neutrophils and is a potent rapid inducer of interleukin 6. PMID:27059843

  16. Dose-Response Analysis of Chemotactic Signaling Response in Salmonella typhimurium LT2 upon Exposure to Cysteine / Cystine Redox Pair

    PubMed Central

    2016-01-01

    The chemotaxis system enables motile bacteria to search for an optimum level of environmental factors. Salmonella typhimurium senses the amino acid cysteine as an attractant and its oxidized dimeric form, cystine, as a repellent. We investigated the dose-response dependence of changes in chemotactic signaling activity upon exposure to cysteine and cystine of S. typhimurium LT2 using in vivo fluorescence resonance energy transfer (FRET) measurements. The dose-response curve of the attractant response to cysteine had a sigmoidal shape, typical for receptor-ligand interactions. However, in a knockout strain of the chemoreceptor genes tsr and tar, we detected a repellent response to cysteine solutions, scaling linearly with the logarithm of the cysteine concentration. Interestingly, the magnitude of the repellent response to cystine also showed linear dependence to the logarithm of the cystine concentration. This linear dependence was observed over more than four orders of magnitude, where detection started at nanomolar concentrations. Notably, low concentrations of another oxidized compound, benzoquinone, triggered similar responses. In contrast to S. typhimurium 14028, where no response to cystine was observed in a knockout strain of chemoreceptor genes mcpB and mcpC, here we showed that McpB / McpC-independent responses to cystine existed in the strain S. typhimurium LT2 even at nanomolar concentrations. Additionally, knocking out mcpB and mcpC did not affect the linear dose-response dependence, whereas enhanced responses were only observed to solutions that where not pH neutral (>100 μM cystine) in the case of McpC overexpression. We discuss that the linear dependence of the response on the logarithm of cystine concentrations could be a result of a McpB / C-independent redox-sensing pathway that exists in S. typhimurium LT2. We supported this hypothesis with experiments with defined cysteine / cystine mixed solutions, where a transition from repellent to

  17. CysLT1 leukotriene receptor antagonists inhibit the effects of nucleotides acting at P2Y receptors

    PubMed Central

    Mamedova, Liaman; Capra, Valérie; Accomazzo, Maria Rosa; Gao, Zhan-Guo; Ferrario, Silvia; Fumagalli, Marta; Abbracchio, Maria P.; Rovati, G. Enrico; Jacobson, Kenneth A.

    2016-01-01

    Montelukast and pranlukast are orally active leukotriene receptor antagonists selective for the CysLT1 receptor. Conversely, the hP2Y1,2,4,6,11,12,13,14 receptors represent a large family of GPCRs responding to either adenine or uracil nucleotides, or to sugar-nucleotides. Montelukast and pranlukast were found to inhibit nucleotide-induced calcium mobilization in a human monocyte-macrophage like cell line, DMSO-differentiated U937 (dU937). Montelukast and pranlukast inhibited the effects of UTP with IC50 values of 7.7 and 4.3 μM, respectively, and inhibited the effects of UDP with IC50 values of 4.5 and 1.6 μM, respectively, in an insurmountable manner. Furthermore, ligand binding studies using [3H]LTD4 excluded the possibility of orthosteric nucleotide binding to the CysLT1 receptor. dU937 cells were shown to express P2Y2, P2Y4, P2Y6, P2Y11, P2Y13 and P2Y14 receptors. Therefore, these antagonists were studied functionally in a heterologous expression system for the human P2Y receptors. In 1321N1 astrocytoma cells stably expressing human P2Y1,2,4,6 receptors, CysLT1 antagonists inhibited both the P2Y agonist-induced activation of phospholipase C and intracellular Ca2+ mobilization. IC50 values at P2Y1 and P2Y6 receptors were <1 μM. In control astrocytoma cells expressing an endogenous M3 muscarinic receptor, 10 μM montelukast had no effect on the carbachol-induced rise in intracellular Ca2+. These data demonstrated that CysLT1 receptor antagonists interact functionally with signaling pathways of P2Y receptors, and this should foster the study of possible implications for the clinical use of these compounds in asthma or in other inflammatory conditions. PMID:16280122

  18. Femtosecond probe-probe transmission studies of LT-grown GaAs near the band edge

    SciTech Connect

    Radousky, H.B.; Bello, A.F.; Erskine, D.J.; Dinh, L.N.; Bennahmias, M.J.; Perry, M.D.; Ditmire, T.R.; Mariella, R.P. Jr.

    1993-12-01

    We have studied the near-edge optical response of a LT-grown GaAs sample which was deposited at 300{degrees}C on a Si substrate, and then annealed at 600{degrees}C. The Si was etched away to leave a 1 micron free standing GaAs film. Femtosecond transmission measurements were made using an equal pulse technique at four wavelengths between 825 and 870 nm. For each wavelength we observe both a multipicosecond relaxation time, as well as a shorter relaxation time which is less than 100 femtoseconds.

  19. Homological stabilizer codes

    SciTech Connect

    Anderson, Jonas T.

    2013-03-15

    In this paper we define homological stabilizer codes on qubits which encompass codes such as Kitaev's toric code and the topological color codes. These codes are defined solely by the graphs they reside on. This feature allows us to use properties of topological graph theory to determine the graphs which are suitable as homological stabilizer codes. We then show that all toric codes are equivalent to homological stabilizer codes on 4-valent graphs. We show that the topological color codes and toric codes correspond to two distinct classes of graphs. We define the notion of label set equivalencies and show that under a small set of constraints the only homological stabilizer codes without local logical operators are equivalent to Kitaev's toric code or to the topological color codes. - Highlights: Black-Right-Pointing-Pointer We show that Kitaev's toric codes are equivalent to homological stabilizer codes on 4-valent graphs. Black-Right-Pointing-Pointer We show that toric codes and color codes correspond to homological stabilizer codes on distinct graphs. Black-Right-Pointing-Pointer We find and classify all 2D homological stabilizer codes. Black-Right-Pointing-Pointer We find optimal codes among the homological stabilizer codes.

  20. Iron reduction by the deep-sea bacterium Shewanella profunda LT13a under subsurface pressure and temperature conditions

    PubMed Central

    Picard, Aude; Testemale, Denis; Wagenknecht, Laura; Hazael, Rachael; Daniel, Isabelle

    2015-01-01

    Microorganisms influence biogeochemical cycles from the surface down to the depths of the continental rocks and oceanic basaltic crust. Due to the poor recovery of microbial isolates from the deep subsurface, the influence of physical environmental parameters, such as pressure and temperature, on the physiology and metabolic potential of subsurface inhabitants is not well constrained. We evaluated Fe(III) reduction rates (FeRRs) and viability, measured as colony-forming ability, of the deep-sea piezophilic bacterium Shewanella profunda LT13a over a range of pressures (0–125 MPa) and temperatures (4–37∘C) that included the in situ habitat of the bacterium isolated from deep-sea sediments at 4500 m depth below sea level. S. profunda LT13a was active at all temperatures investigated and at pressures up to 120 MPa at 30∘C, suggesting that it is well adapted to deep-sea and deep sedimentary environments. Average initial cellular FeRRs only slightly decreased with increasing pressure until activity stopped, suggesting that the respiratory chain was not immediately affected upon the application of pressure. We hypothesize that, as pressure increases, the increased energy demand for cell maintenance is not fulfilled, thus leading to a decrease in viability. This study opens up perspectives about energy requirements of cells in the deep subsurface. PMID:25653646

  1. Iron reduction by the deep-sea bacterium Shewanella profunda LT13a under subsurface pressure and temperature conditions.

    PubMed

    Picard, Aude; Testemale, Denis; Wagenknecht, Laura; Hazael, Rachael; Daniel, Isabelle

    2014-01-01

    Microorganisms influence biogeochemical cycles from the surface down to the depths of the continental rocks and oceanic basaltic crust. Due to the poor recovery of microbial isolates from the deep subsurface, the influence of physical environmental parameters, such as pressure and temperature, on the physiology and metabolic potential of subsurface inhabitants is not well constrained. We evaluated Fe(III) reduction rates (FeRRs) and viability, measured as colony-forming ability, of the deep-sea piezophilic bacterium Shewanella profunda LT13a over a range of pressures (0-125 MPa) and temperatures (4-37∘C) that included the in situ habitat of the bacterium isolated from deep-sea sediments at 4500 m depth below sea level. S. profunda LT13a was active at all temperatures investigated and at pressures up to 120 MPa at 30∘C, suggesting that it is well adapted to deep-sea and deep sedimentary environments. Average initial cellular FeRRs only slightly decreased with increasing pressure until activity stopped, suggesting that the respiratory chain was not immediately affected upon the application of pressure. We hypothesize that, as pressure increases, the increased energy demand for cell maintenance is not fulfilled, thus leading to a decrease in viability. This study opens up perspectives about energy requirements of cells in the deep subsurface. PMID:25653646

  2. Evaluation of Metal Halide, Plasma, and LED Lighting Technologies for a Hydrogen Fuel Cell Mobile Light (H 2 LT)

    DOE PAGESBeta

    Miller, L. B.; Donohoe, S. P.; Jones, M. H.; White, W. A.; Klebanoff, L. E.; Velinsky, S. A.

    2015-04-22

    This article reports on the testing and comparison of a prototype hydrogen fuel cell light tower (H2LT) and a conventional diesel-powered metal halide light trailer for use in road maintenance and construction activities. The prototype was originally outfitted with plasma lights and then with light-emitting diode (LED) luminaires. Light output and distribution, lighting energy efficiency (i.e., efficacy), power source thermal efficiency, and fuel costs are compared. The metal halide luminaires have 2.2 and 3.1 times more light output than the plasma and LED luminaires, respectively, but they require more power/lumen to provide that output. The LED luminaires have 1.6 timesmore » better light efficacy than either the metal halide or plasma luminaires. The light uniformity ratios produced by the plasma and LED towers are acceptable. The fuel cell thermal efficiency at the power required to operate the plasma lights is 48%, significantly higher than the diesel generator efficiency of 23% when operating the metal halide lights. Due to the increased efficiency of the fuel cell and the LED lighting, the fuel cost per lumen-hour of the H2LT is 62% of the metal halide diesel light tower assuming a kilogram of hydrogen is twice the cost of a gallon of diesel fuel.« less

  3. In vitro inhibition of ETEC K88 adhesion by pea hulls and of LT enterotoxin binding by faba bean hulls.

    PubMed

    Becker, P M; van der Meulen, J; Jansman, A J M; van Wikselaar, P G

    2012-12-01

    Enterotoxigenic Escherichia coli (ETEC) expressing K88 (F4) adhesins are associated with post-weaning diarrhoea in piglets. Different grain fractions from pea (Pisum sativum) and faba bean (Vicia faba) were tested in vitro for their capacity to counteract aetiological factors, which contribute to the development of diarrhoea. In detail, adhesion of E. coli O149:K91:K88ac (ETEC K88ac) to grain legume products, intended to impair the colonization of the host, was studied as well as interference with receptor binding of the pathogen's heat-labile enterotoxin LT, intended to reduce toxin-inflicted gut cell damage. When comparing different pea and faba bean products tested for their binding capacity of ETEC K88ac, especially pea hulls, but also whole pea meal, starch-enriched and protein-enriched pea meal, and digestion-resistant pea hull and meal fractions showed a higher binding of ETEC K88ac than faba bean products. In contrast to the ETEC K88ac adhesion results, bean hulls proved more effective than pea hulls in preventing GM1 receptor binding of LT. Previous small intestinal segment perfusion experiments we performed with ETEC K88ac-challenged piglets indicated that both pea and bean hulls have the potential for successful application in diarrhoea prophylaxis and treatment, which is in agreement with and refined by our detection of their different modes of functioning. PMID:21929729

  4. Coding of Neuroinfectious Diseases.

    PubMed

    Barkley, Gregory L

    2015-12-01

    Accurate coding is an important function of neurologic practice. This contribution to Continuum is part of an ongoing series that presents helpful coding information along with examples related to the issue topic. Tips for diagnosis coding, Evaluation and Management coding, procedure coding, or a combination are presented, depending on which is most applicable to the subject area of the issue. PMID:26633789

  5. Model Children's Code.

    ERIC Educational Resources Information Center

    New Mexico Univ., Albuquerque. American Indian Law Center.

    The Model Children's Code was developed to provide a legally correct model code that American Indian tribes can use to enact children's codes that fulfill their legal, cultural and economic needs. Code sections cover the court system, jurisdiction, juvenile offender procedures, minor-in-need-of-care, and termination. Almost every Code section is…

  6. Double-Spin Asymmetry A{sub LT} for Polarized Drell-Yan Process in pp-bar Collisions: Wandzura-Wilczek Contribution

    SciTech Connect

    Koike, Yuji; Yoshida, Shinsuke; Tanaka, Kazuhiro

    2009-08-04

    The longitudinal-transverse spin asymmetry A{sub LT} in the polarized Drell-Yan process depends on twist-3 quark distributions of nucleon. In addition to the contributions associated with the twist-3 operators, these distributions contain the 'Wandzura-Wilczek (WW)' part, which is determined by a certain integral of twist-2 distributions. The recently obtained empirical information on the transversity allows a realistic estimate of the WW contribution to A{sub LT} for the polarized pp-bar collisions. Our results indicate that rather large A{sub LT}({approx}10%) can be observed in the proposed spin experiments at GSI, with novel pattern as a function of dilepton mass compared with A{sub TT} and A{sub LL}.

  7. Discovery of a Visual T-dwarf Triple System and Binarity at the L/T Transition

    NASA Astrophysics Data System (ADS)

    Radigan, Jacqueline; Jayawardhana, Ray; Lafrenière, David; Dupuy, Trent J.; Liu, Michael C.; Scholz, Alexander

    2013-11-01

    We present new high contrast imaging of eight L/T transition brown dwarfs (BDs) using the NIRC2 camera on the Keck II telescope. One of our targets, the T3.5 dwarf 2MASS J08381155+1511155, was resolved into a hierarchal triple with projected separations of 2.5 ± 0.5 AU and 27 ± 5 AU for the BC and A(BC) components, respectively. Resolved OSIRIS spectroscopy of the A(BC) components confirms that all system members are T dwarfs. The system therefore constitutes the first triple T-dwarf system ever reported. Using resolved photometry to model the integrated-light spectrum, we infer spectral types of T3 ± 1, T3 ± 1, and T4.5 ± 1 for the A, B, and C components, respectively. The uniformly brighter primary has a bluer J - Ks color than the next faintest component, which may reflect a sensitive dependence of the L/T transition temperature on gravity, or alternatively divergent cloud properties among components. Relying on empirical trends and evolutionary models we infer a total system mass of 0.034-0.104 M ⊙ for the BC components at ages of 0.3-3 Gyr, which would imply a period of 12-21 yr assuming the system semimajor axis to be similar to its projection. We also infer differences in effective temperatures and surface gravities between components of no more than ~150 K and ~0.1 dex. Given the similar physical properties of the components, the 2M0838+15 system provides a controlled sample for constraining the relative roles of effective temperature, surface gravity, and dust clouds in the poorly understood L/T transition regime. For an age of 3 Gyr we estimate a binding energy of ~20 × 1041 erg for the wide A(BC) pair, which falls above the empirical minimum found for typical BD binaries, and suggests that the system may have been able to survive a dynamical ejection during formation. Combining our imaging survey results with previous work we find an observed binary fraction of 4/18 or 22_{-8}^{+10}% for unresolved spectral types of L9-T4 at separations >~ 0

  8. Low Temperature Scanning Probe Microscope(LT-SPM) operating in a Cryogen-Free Cryostat, 1.5-300K

    NASA Astrophysics Data System (ADS)

    Karci, Ozgur; Dede, Munir; Bugoslavsky, Yury; Hall, Renny; Oral, Ahmet; Nanomagnetics Instruments Ltd. Team; Cryogenic Limited Team; Sabanci University Team

    2011-03-01

    We present the design of a Low Temperature Scanning Probe Microscope(LT-SFM) operating in a vibration-free cryogen-free cryostat. A 0.5W ultra now noise Pulse Tube cryocooler is integrated into the cryostat with a 9T magnet. Stick slip coarse approach mechanism is used to bring the sample in to close proximity of the sample. The sample can be moved in XY directions within 3 mm range, while the position is measured with capacitive encoder with 3 μ m accuracy. An improved fiber interferometer with ~ 12 fm/ √ Hz noise level is used to detect cantilever deflection. The resonance of the cantilever controlled by a digital Phase Locked Loop (PLL) integrated in our Control Electronics with 5mHz frequency resolution. We can achieve ~ 1 nm resolution in AFM mode & <10nm resolution in MFM mode. Results from different imaging modes; non-contact AFM, MFM, Piezoresponse, Conductive AFM etc. will be presented.

  9. Discovery of a visual T-dwarf triple system and binarity at the L/T transition

    SciTech Connect

    Radigan, Jacqueline; Jayawardhana, Ray; Lafrenière, David; Dupuy, Trent J.; Liu, Michael C.; Scholz, Alexander

    2013-11-20

    We present new high contrast imaging of eight L/T transition brown dwarfs (BDs) using the NIRC2 camera on the Keck II telescope. One of our targets, the T3.5 dwarf 2MASS J08381155+1511155, was resolved into a hierarchal triple with projected separations of 2.5 ± 0.5 AU and 27 ± 5 AU for the BC and A(BC) components, respectively. Resolved OSIRIS spectroscopy of the A(BC) components confirms that all system members are T dwarfs. The system therefore constitutes the first triple T-dwarf system ever reported. Using resolved photometry to model the integrated-light spectrum, we infer spectral types of T3 ± 1, T3 ± 1, and T4.5 ± 1 for the A, B, and C components, respectively. The uniformly brighter primary has a bluer J – K{sub s} color than the next faintest component, which may reflect a sensitive dependence of the L/T transition temperature on gravity, or alternatively divergent cloud properties among components. Relying on empirical trends and evolutionary models we infer a total system mass of 0.034-0.104 M {sub ☉} for the BC components at ages of 0.3-3 Gyr, which would imply a period of 12-21 yr assuming the system semimajor axis to be similar to its projection. We also infer differences in effective temperatures and surface gravities between components of no more than ∼150 K and ∼0.1 dex. Given the similar physical properties of the components, the 2M0838+15 system provides a controlled sample for constraining the relative roles of effective temperature, surface gravity, and dust clouds in the poorly understood L/T transition regime. For an age of 3 Gyr we estimate a binding energy of ∼20 × 10{sup 41} erg for the wide A(BC) pair, which falls above the empirical minimum found for typical BD binaries, and suggests that the system may have been able to survive a dynamical ejection during formation. Combining our imaging survey results with previous work we find an observed binary fraction of 4/18 or 22{sub −8}{sup +10}% for unresolved spectral types

  10. Accumulate repeat accumulate codes

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative channel coding scheme called 'Accumulate Repeat Accumulate codes' (ARA). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes, thus belief propagation can be used for iterative decoding of ARA codes on a graph. The structure of encoder for this class can be viewed as precoded Repeat Accumulate (RA) code or as precoded Irregular Repeat Accumulate (IRA) code, where simply an accumulator is chosen as a precoder. Thus ARA codes have simple, and very fast encoder structure when they representing LDPC codes. Based on density evolution for LDPC codes through some examples for ARA codes, we show that for maximum variable node degree 5 a minimum bit SNR as low as 0.08 dB from channel capacity for rate 1/2 can be achieved as the block size goes to infinity. Thus based on fixed low maximum variable node degree, its threshold outperforms not only the RA and IRA codes but also the best known LDPC codes with the dame maximum node degree. Furthermore by puncturing the accumulators any desired high rate codes close to code rate 1 can be obtained with thresholds that stay close to the channel capacity thresholds uniformly. Iterative decoding simulation results are provided. The ARA codes also have projected graph or protograph representation that allows for high speed decoder implementation.

  11. Concatenated Coding Using Trellis-Coded Modulation

    NASA Technical Reports Server (NTRS)

    Thompson, Michael W.

    1997-01-01

    In the late seventies and early eighties a technique known as Trellis Coded Modulation (TCM) was developed for providing spectrally efficient error correction coding. Instead of adding redundant information in the form of parity bits, redundancy is added at the modulation stage thereby increasing bandwidth efficiency. A digital communications system can be designed to use bandwidth-efficient multilevel/phase modulation such as Amplitude Shift Keying (ASK), Phase Shift Keying (PSK), Differential Phase Shift Keying (DPSK) or Quadrature Amplitude Modulation (QAM). Performance gain can be achieved by increasing the number of signals over the corresponding uncoded system to compensate for the redundancy introduced by the code. A considerable amount of research and development has been devoted toward developing good TCM codes for severely bandlimited applications. More recently, the use of TCM for satellite and deep space communications applications has received increased attention. This report describes the general approach of using a concatenated coding scheme that features TCM and RS coding. Results have indicated that substantial (6-10 dB) performance gains can be achieved with this approach with comparatively little bandwidth expansion. Since all of the bandwidth expansion is due to the RS code we see that TCM based concatenated coding results in roughly 10-50% bandwidth expansion compared to 70-150% expansion for similar concatenated scheme which use convolution code. We stress that combined coding and modulation optimization is important for achieving performance gains while maintaining spectral efficiency.

  12. Coset Codes Viewed as Terminated Convolutional Codes

    NASA Technical Reports Server (NTRS)

    Fossorier, Marc P. C.; Lin, Shu

    1996-01-01

    In this paper, coset codes are considered as terminated convolutional codes. Based on this approach, three new general results are presented. First, it is shown that the iterative squaring construction can equivalently be defined from a convolutional code whose trellis terminates. This convolutional code determines a simple encoder for the coset code considered, and the state and branch labelings of the associated trellis diagram become straightforward. Also, from the generator matrix of the code in its convolutional code form, much information about the trade-off between the state connectivity and complexity at each section, and the parallel structure of the trellis, is directly available. Based on this generator matrix, it is shown that the parallel branches in the trellis diagram of the convolutional code represent the same coset code C(sub 1), of smaller dimension and shorter length. Utilizing this fact, a two-stage optimum trellis decoding method is devised. The first stage decodes C(sub 1), while the second stage decodes the associated convolutional code, using the branch metrics delivered by stage 1. Finally, a bidirectional decoding of each received block starting at both ends is presented. If about the same number of computations is required, this approach remains very attractive from a practical point of view as it roughly doubles the decoding speed. This fact is particularly interesting whenever the second half of the trellis is the mirror image of the first half, since the same decoder can be implemented for both parts.

  13. The novel adjuvant dmLT promotes dose sparing, mucosal immunity and longevity of antibody responses to the inactivated polio vaccine in a murine model.

    PubMed

    Norton, Elizabeth B; Bauer, David L; Weldon, William C; Oberste, M Steven; Lawson, Louise B; Clements, John D

    2015-04-15

    One option for achieving global polio eradication is to replace the oral poliovirus vaccine (OPV), which has the risk of reversion to wild-type virulence, with the inactivated poliovirus vaccine (IPV) vaccine. Adjuvants and alternate routes of immunization are promising options that may reduce antigen dose in IPV vaccinations, potentially allowing dose sparing and cost savings. Use of adjuvants and alternate routes of immunization could also help promote mucosal immunity, potentially mimicking the protection against intestinal virus shedding seen with OPV. In the current study, we examined the impact of combining the novel adjuvant dmLT with trivalent IPV for dose sparing, induction of mucosal immunity and increasing longevity of anti-poliovirus (PV) responses in a mouse model following either intradermal (ID) or intramuscular (IM) delivery. We found that non-adjuvanted ID delivery was not superior to IM delivery for fractional dose sparing, but was associated with development of mucosal immunity. Vaccination with IPV+dmLT promoted serum anti-PV neutralizing antibodies with fractional IPV doses by either IM or ID delivery, achieving at least five-fold dose sparing above non-adjuvanted fractional doses. These responses were most noticeable with the PV1 component of the trivalent vaccine. dmLT also promoted germinal center formation and longevity of serum anti-PV neutralizing titers. Lastly, dmLT enhanced mucosal immunity, as defined by fecal and intestinal anti-PV IgA secretion, when included in IPV immunization by ID or IM delivery. These studies demonstrate that dmLT is an effective adjuvant for either IM or ID delivery of IPV. Inclusion of dmLT in IPV immunizations allows antigen dose sparing and enhances mucosal immunity and longevity of anti-PV responses. PMID:25765967

  14. Acetohydroxy acid synthase I is required for isoleucine and valine biosynthesis by Salmonella typhimurium LT2 during growth on acetate or long-chain fatty acids.

    PubMed

    Dailey, F E; Cronan, J E; Maloy, S R

    1987-02-01

    Salmonella typhimurium LT2 normally expresses two acetohydroxy acid synthases (AHAS I and AHAS II). The function of AHAS I in this organism was unclear, since AHAS I-deficient (ilvBN) mutants of LT2 grew well on glucose or succinate minimal media, whereas AHAS II-deficient (ilvGM) mutants requried isoleucine for normal growth on glucose minimal media. We report that AHAS I-deficient mutants of S. typhimurium required isoleucine and valine for growth on acetate or oleate minimal media, whereas AHAS II-deficient mutants were able to grow on these media without isoleucine supplementation. PMID:3542980

  15. Lack of activity of 15-epi-lipoxin A4 on FPR2/ALX and CysLT1 receptors in interleukin-8-driven human neutrophil function

    PubMed Central

    Planagumà, A; Domenech, T; Jover, I; Ramos, I; Sentellas, S; Malhotra, R; Miralpeix, M

    2013-01-01

    Neutrophil recruitment and survival are important control points in the development and resolution of inflammatory processes. 15-epi-lipoxin (LX)A4 interaction with formyl peptide receptor 2 (FPR2)/ALX receptor is suggested to enhance anti-inflammatory neutrophil functions and mediate resolution of airway inflammation. However, it has been reported that 15-epi-LXA4 analogues can also bind to cysteinyl leukotriene receptor 1 (CysLT1) and that the CysLT1 antagonist MK-571 binds to FPR2/ALX, so cross-reactivity between FPR2/ALX and CysLT1 ligands cannot be discarded. It is not well established whether the resolution properties reported for 15-epi-LXA4 are mediated through FPR2/ALX, or if other receptors such as CysLT1 may also be involved. Evaluation of specific FPR2/ALX ligands and CysLT1 antagonists in functional biochemical and cellular assays were performed to establish a role for both receptors in 15-epi-LXA4-mediated signalling and function. In our study, a FPR2/ALX synthetic peptide (WKYMVm) and a small molecule FPR2/ALX agonist (compound 43) induced FPR2/ALX-mediated signalling, enhancing guanosine triphosphate-gamma (GTPγ) binding and decreasing cyclic adenosine monophosphate (cAMP) levels, whereas 15-epi-LXA4 was inactive. Furthermore, 15-epi-LXA4 showed neither binding affinity nor signalling towards CysLT1. In neutrophils, 15-epi-LXA4 showed a moderate reduction of interleukin (IL)-8-mediated neutrophil chemotaxis but no effect on neutrophil survival was observed. In addition, CysLT1 antagonists were inactive in FPR2/ALX signalling or neutrophil assays. In conclusion, 15-epi-LXA4 is not a functional agonist or an antagonist of FPR2/ALX or CysLT1, shows no effect on IL-8-induced neutrophil survival and produces only moderate inhibition in IL-8-mediated neutrophil migration. Our data do not support an anti-inflammatory role of 15-epi-LXA4- FPR2/ALX interaction in IL-8-induced neutrophil inflammation. PMID:23607720

  16. Deformation and seismic precursors to dome-collapse and fountain-collapse nuées ardentes at Merapi Volcano, Java, Indonesia, 1994-1998

    USGS Publications Warehouse

    Voight, B.; Young, K.D.; Hidayat, D.; Subandrio; Purbawinata, M.A.; Ratdomopurbo, A.; Suharna; Panut; Sayudi, D.S.; LaHusen, R.; Marso, J.; Murray, T.L.; Dejean, M.; Iguchi, M.; Ishihara, K.

    2000-01-01

    Following the eruption of January 1992, episodes of lava dome growth accompanied by generation of dome-collapse nuées ardentes occurred in 1994–1998. In addition, nuées ardentes were generated by fountain-collapse in January 1997, and the 1998 events also suggest an explosive component. Significant tilt and seismic precursors on varying time scales preceded these events. Deformation about the summit has been detected by electronic tiltmeters since November 1992, with inflation corresponding generally to lava dome growth, and deflation (or decreased inflation) corresponding to loss of dome mass. Strong short-term (days to weeks) accelerations in tilt rate and seismicity occurred prior to the major nuées ardentes episodes, apart from those of 22 November 1994 which were preceded by steadily increasing tilt for over 200 days but lacked short-term precursors. Because of the combination of populated hazardous areas and the lack of an issued warning, about 100 casualties occurred in 1994. In contrast, the strong precursors in 1997 and 1998 provided advance warning to observatory scientists, enabled the stepped raising of alert levels, and aided hazard management. As a result of these factors, but also the fortunate fact that the large nuées ardentes did not quite descend into populated areas, no casualties occurred. The nuée ardente episode of 1994 is interpreted as purely due to gravitational collapse, whereas those of 1997 and 1998 were influenced by gas-pressurization of the lava dome.

  17. Methods to determine transit losses for return flows of transmountain water in Fountain Creek between Colorado Springs and the Arkansas River, Colorado

    USGS Publications Warehouse

    Kuhn, Gerhard

    1988-01-01

    Methods were developed by which transit losses could be determined for transmountain return flows in Fountain Creek between Colorado Springs, Colorado, and its confluence with the Arkansas River. The study reach is a complex hydrologic system wherein a substantially variable streamflow interacts with an alluvial aquifer. The study approach included: (1) calibration and verification of a streamflow-routing model that contained a bank-storage-discharge component; (2) use of the model to develop the methods by which transit losses could be calculated; and (3) design of an application method for calculating daily transit loss using the model results. Sources of transit losses that were studied are bank storage, channel storage, and evaporation. Magnitude of bank-storage loss primarily depends on duration of a recovery period during which water lost to bank storage is returned to the stream. Net loss to bank storage can vary from about 50% for a 0-day recovery period to about 2% for a 180-day recovery period. Virtually all water lost to bank storage could be returned to the stream with longer recovery periods. Channel-storage loss was determined to be about 10% of a release quantity. Because the loss on any given day is totally recovered in the form of gains from channel storage on the subsequent day, channel storage is a temporary transit loss. Evaporation loss generally is less than 5% of a given daily transmountain return-flow release, depending on month of year. Evaporation losses are permanently lost from the system. (USGS)

  18. Discussion on LDPC Codes and Uplink Coding

    NASA Technical Reports Server (NTRS)

    Andrews, Ken; Divsalar, Dariush; Dolinar, Sam; Moision, Bruce; Hamkins, Jon; Pollara, Fabrizio

    2007-01-01

    This slide presentation reviews the progress that the workgroup on Low-Density Parity-Check (LDPC) for space link coding. The workgroup is tasked with developing and recommending new error correcting codes for near-Earth, Lunar, and deep space applications. Included in the presentation is a summary of the technical progress of the workgroup. Charts that show the LDPC decoder sensitivity to symbol scaling errors are reviewed, as well as a chart showing the performance of several frame synchronizer algorithms compared to that of some good codes and LDPC decoder tests at ESTL. Also reviewed is a study on Coding, Modulation, and Link Protocol (CMLP), and the recommended codes. A design for the Pseudo-Randomizer with LDPC Decoder and CRC is also reviewed. A chart that summarizes the three proposed coding systems is also presented.

  19. Manually operated coded switch

    DOEpatents

    Barnette, Jon H.

    1978-01-01

    The disclosure relates to a manually operated recodable coded switch in which a code may be inserted, tried and used to actuate a lever controlling an external device. After attempting a code, the switch's code wheels must be returned to their zero positions before another try is made.

  20. Binary primitive alternant codes

    NASA Technical Reports Server (NTRS)

    Helgert, H. J.

    1975-01-01

    In this note we investigate the properties of two classes of binary primitive alternant codes that are generalizations of the primitive BCH codes. For these codes we establish certain equivalence and invariance relations and obtain values of d and d*, the minimum distances of the prime and dual codes.

  1. Algebraic geometric codes

    NASA Technical Reports Server (NTRS)

    Shahshahani, M.

    1991-01-01

    The performance characteristics are discussed of certain algebraic geometric codes. Algebraic geometric codes have good minimum distance properties. On many channels they outperform other comparable block codes; therefore, one would expect them eventually to replace some of the block codes used in communications systems. It is suggested that it is unlikely that they will become useful substitutes for the Reed-Solomon codes used by the Deep Space Network in the near future. However, they may be applicable to systems where the signal to noise ratio is sufficiently high so that block codes would be more suitable than convolutional or concatenated codes.

  2. ARA type protograph codes

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush (Inventor); Abbasfar, Aliazam (Inventor); Jones, Christopher R. (Inventor); Dolinar, Samuel J. (Inventor); Thorpe, Jeremy C. (Inventor); Andrews, Kenneth S. (Inventor); Yao, Kung (Inventor)

    2008-01-01

    An apparatus and method for encoding low-density parity check codes. Together with a repeater, an interleaver and an accumulator, the apparatus comprises a precoder, thus forming accumulate-repeat-accumulate (ARA codes). Protographs representing various types of ARA codes, including AR3A, AR4A and ARJA codes, are described. High performance is obtained when compared to the performance of current repeat-accumulate (RA) or irregular-repeat-accumulate (IRA) codes.

  3. QR Codes 101

    ERIC Educational Resources Information Center

    Crompton, Helen; LaFrance, Jason; van 't Hooft, Mark

    2012-01-01

    A QR (quick-response) code is a two-dimensional scannable code, similar in function to a traditional bar code that one might find on a product at the supermarket. The main difference between the two is that, while a traditional bar code can hold a maximum of only 20 digits, a QR code can hold up to 7,089 characters, so it can contain much more…

  4. 75 FR 73156 - The Amended Designation of Lashkar-e-Tayyiba (LT, LeT), aka Lashkar-e-Toiba, aka Lashkar-i-Taiba...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE The Amended Designation of Lashkar-e-Tayyiba (LT, LeT), aka Lashkar-e-Toiba, aka Lashkar-i-Taiba, aka al Mansoorian, aka al Mansooreen, aka Army of the Pure, aka Army of the Righteous, aka Army of the Pure...

  5. GUIDANCE DOCUMENT ON IMPLEMENTATION OF THE MICROBIAL TOOLBOX FOR COMPLIANCE WITH LONG TERM 2 ENHANCED SURFACE WATER TREATMENT RULE (LT2ESWTR)

    EPA Science Inventory

    The Agreement in Principle for the Stage 2 M-DBP Federal Advisory Committee contains a list of treatment processes and management practices for water systems to use in meeting additional Cryptosporidium treatment requirements under the LT2ESWTR. This list, termed the microbial t...

  6. [Determination of LC 90 and LT 90 of IBCB66 Beauveria bassiana (Ascomycetes: Clavicipitaceae) isolate for Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) control].

    PubMed

    Barci, Leila A G; de Almeida, José Eduardo M; de Campos Nogueira, Adriana H; do Prado, Angelo P

    2009-12-01

    The objective of this research was to evaluate the pathogenicity and the virulence of the IBCB66 isolate of Beauveria bassiana on infected larvae of Rhipicephalus (Boophilus) microplus. The IBCB66 fungus strain was used as standard isolates of B. bassiana against R. (B.) microplus larvae. The larval bioassay tests using the IBCB66 isolate were carried out to determine the (Lethal Concentration) LC50, LC90, (Lethal Time) LT50 and LT90. The IBCB66 fungus strain was tested at six different concentrations (5x10(6), 10(7), 5x10(7), 10(8), 5x10(8) and 10(9) conidia.mL(-1)) to determine the percentage of larval mortality. In addition, a Probit analysis was also performed. Total larval mortality was observed eighteen days after the beginning of the test in the group treated with 5x10(9) conidia.mL(1). The LC50 and LC90 were 3x10(7) and 5x10(8) respectively and the LT50 and LT90 were 10 and 16 days. PMID:20040188

  7. Both enzymatic and non-enzymatic properties of heat-labile enterotoxin are responsible for LT-enhanced adherence of enterotoxigenic Escherichia coli to porcine IPEC-J2 cells.

    PubMed

    Fekete, Peter Z; Mateo, Kristina S; Zhang, Weiping; Moxley, Rodney A; Kaushik, Radhey S; Francis, David H

    2013-06-28

    Previous studies in piglets indicate that heat labile enterotoxin (LT) expression enhances intestinal colonization by K88 adhesin-producing enterotoxigenic Escherichia coli (ETEC) as wild-type ETEC adhered to intestinal epithelium in substantially greater numbers than did non-toxigenic constructs. Enzymatic activity of the toxin was also shown to contribute to the adhesion of ETEC and non-ETEC bacteria to epithelial cells in culture. To further characterize the contribution of LT to host cell adhesion, a nontoxigenic, K88-producing E. coli was transformed with either the gene encoding for LT holotoxin, a catalytically-attenuated form of the toxin [LT(R192G)], or LTB subunits, and resultant changes in bacterial adherence to IPEC-J2 porcine intestinal epithelial cells were measured. Strains expressing LT holotoxin or mutants were able to adhere in significantly higher numbers to IPEC-J2 cells than was an isogenic, toxin-negative construct. LT+ strains were also able to significantly block binding of a wild-type LT+ ETEC strain to IPEC-J2 cells. Adherence of isogenic strains to IPEC-J2 cells was unaltered by cycloheximide treatment, suggesting that LT enhances ETEC adherence to IPEC-J2 cells independent of host cell protein synthesis. However, pretreating IPEC-J2 cells with LT promoted adherence of negatively charged latex beads (a surrogate for bacteria which carry a negative change), which adherence was inhibited by cycloheximide, suggesting LT may induce a change in epithelial cell membrane potential. Overall, these data suggest that LT may enhance ETEC adherence by promoting an association between LTB and epithelial cells, and by altering the surface charge of the host plasma membrane to promote non-specific adherence. PMID:23517763

  8. Asymmetric quantum convolutional codes

    NASA Astrophysics Data System (ADS)

    La Guardia, Giuliano G.

    2016-01-01

    In this paper, we construct the first families of asymmetric quantum convolutional codes (AQCCs). These new AQCCs are constructed by means of the CSS-type construction applied to suitable families of classical convolutional codes, which are also constructed here. The new codes have non-catastrophic generator matrices, and they have great asymmetry. Since our constructions are performed algebraically, i.e. we develop general algebraic methods and properties to perform the constructions, it is possible to derive several families of such codes and not only codes with specific parameters. Additionally, several different types of such codes are obtained.

  9. Effects of shoeing on intra- and inter-limb coordination and movement consistency in Icelandic horses at walk, tölt and trot.

    PubMed

    Weishaupt, Michael A; Waldern, Nina M; Amport, Claude; Ramseier, Lea C; Wiestner, Thomas

    2013-12-01

    To enhance expressiveness of forelimb movement and improve the four-beat rhythm of the tölt, Icelandic horses are commonly ridden with excessively high and long hooves. The aim of this study was to objectively assess the effect of shoeing on intra- and inter-limb coordination and limb movement consistency (inter-stride variability) at walk, tölt and trot. Thirteen sound and fit Icelandic horses accustomed to exercise with a rider on a treadmill were assessed with long and high hooves commonly used for competition (S(H)) and with the hooves trimmed according to the standards of normal shoeing (S(N)). Limb timing variables were extracted from the four vertical ground reaction force curves measured with an instrumented treadmill. Measurements were taken at walk and at two tölting and trotting speeds. High hooves with long toes reduced stride rate and increased breakover duration. At the tölt, the footfall rhythm showed less tendency to lateral couplets. Movement consistency of the walk remained unchanged, whereas, at the tölt, stride-to-stride variability of selected time parameters increased in SH and/or at the higher velocity. At the faster trotting speed, variability of hind limb duty factor decreased, whereas variability of contralateral step duration in the forelimb increased. High hooves with long toes improve the clearness of the four-beat footfall rhythm of the tölt, but disturb the movement consistency of the gait. The prolonged breakover duration observed in all gaits may have negative implications for the health of the palmar structures of the distal foot. PMID:24345777

  10. The 12-13 January 2011 lava fountain of Mt. Etna volcano: total mass and grain-size evaluation of the fallout deposit

    NASA Astrophysics Data System (ADS)

    Andronico, Daniele; Cristaldi, Antonio; Lo Castro, Maria Deborah; Scollo, Simona

    2013-04-01

    South-East Crater (SEC) of Mt Etna, Italy, is renowned for its sequences of paroxysms, otherwise called episodic eruptions, which produced more than 150 events since 1998. Each episode typically gives rise to eruption columns and fallout deposits over distances of up to several tens of km from the vent. The last sequence consisted of twenty-five lava fountains occurred between 12 January 2011 and 24 April 2012. The 2011-12 sequence began from a pit-vent located on the eastern flank of the cone; with time, the intense and recurrent paroxysmal activity was able to build a new cone above the SEC, renamed New South-East Crater. The first episode was preceded by the resumption of Strombolian activity on 11 January 2011; late in the afternoon of 12 January, the increasing of explosion intensity and frequency led to the formation of powerful magma jets and a dense eruption column which moved toward SSW. The paroxysmal activity lasted about 1 hour and half; afterward it almost abruptly stopped early on 13 January, thus causing also the end of the eruption plume. Based on prevalent winds blowing in the Etnean area, most of the fallout deposits from Etna disperse their tephra fallout eastward toward the Valle del Bove depression, difficulty accessible in the upper part, then reaching the Ionian Sea. These peculiar conditions usually prevent direct observation of the deposit within 5 km from and 15 km beyond the eruptive vent. The 12-13 January lava fountain fallout, conversely, was dispersed over the South of Etna, exceeding the southern coastline of Sicily and thus giving the chance to map, sample and describe for more than 100 km the tephra fallout, passing from a black scoria deposit to ash deposit (90 % of which formed by sideromelane particles). In particular, the proximal deposit (up to 5 km of distance from SEC) was composed of a continuous to almost continuous tephra blanket containing decimetric-sized scoriae to coarse lapilli, while the most distal sites were

  11. The Evolution of Gas Clouds Falling in the Magnetized Galactic Halo: High-Velocity Clouds (HVCs) Originated in the Galactic Fountain

    NASA Astrophysics Data System (ADS)

    Kwak, Kyujin; Shelton, Robin L.; Raley, Elizabeth A.

    2009-07-01

    In the Galactic fountain scenario, supernovae and/or stellar winds propel material into the Galactic halo. As the material cools, it condenses into clouds. By using FLASH three-dimensional magnetohydrodynamic simulations, we model and study the dynamical evolution of these gas clouds after they form and begin to fall toward the Galactic plane. In our simulations, we assume that the gas clouds form at a height of z = 5 kpc above the Galactic midplane, then begin to fall from rest. We investigate how the cloud's evolution, dynamics, and interaction with the interstellar medium (ISM) are affected by the initial mass of the cloud. We find that clouds with sufficiently large initial densities (n >= 0.1 H atoms cm-3) accelerate sufficiently and maintain sufficiently large column densities as to be observed and identified as high-velocity clouds (HVCs) even if the ISM is weakly magnetized (1.3 μG). However, the ISM can provide noticeable resistance to the motion of a low-density cloud (n <= 0.01 H atoms cm-3) thus making it more probable that a low-density cloud will attain the speed of an intermediate-velocity cloud rather than the speed of an HVC. We also investigate the effects of various possible magnetic field configurations. As expected, the ISM's resistance is greatest when the magnetic field is strong and perpendicular to the motion of the cloud. The trajectory of the cloud is guided by the magnetic field lines in cases where the magnetic field is oriented diagonal to the Galactic plane. The model cloud simulations show that the interactions between the cloud and the ISM can be understood via analogy to the shock tube problem which involves shock and rarefaction waves. We also discuss accelerated ambient gas, streamers of material ablated from the clouds, and the cloud's evolution from a sphere-shaped to a disk- or cigar-shaped object.

  12. Maser and infrared studies of oxygen-rich late/post-asymptotic giant branch stars and water fountains: development of a new identification method

    SciTech Connect

    Yung, Bosco H. K.; Nakashima, Jun-ichi; Henkel, Christian

    2014-10-10

    We explored an efficient method to identify evolved stars with oxygen-rich envelopes in the late asymptotic giant branch (AGB) or post-AGB phase of stellar evolution, which include a rare class of objects—the 'water fountains (WF)'. Our method considers the OH and H{sub 2}O maser spectra, the near-infrared Q-parameters (these are color indices accounting for the effect of extinction), and far-infrared AKARI colors. Here we first present the results of a new survey on OH and H{sub 2}O masers. There were 108 color-selected objects: 53 of them were observed in the three OH maser lines (1612, 1665, and 1667 MHz), with 24 detections (16 new for 1612 MHz); and 106 of them were observed in the H{sub 2}O maser line (22 GHz), with 24 detections (12 new). We identify a new potential WF source, IRAS 19356+0754, with large velocity coverages of both OH and H{sub 2}O maser emission. In addition, several objects with high-velocity OH maser emission are reported for the first time. The Q-parameters as well as the infrared [09]–[18] and [18]–[65] AKARI colors of the surveyed objects are then calculated. We suggest that these infrared properties are effective in isolating aspherical from spherical objects, but the morphology may not necessarily be related to the evolutionary status. Nonetheless, by considering altogether the maser and infrared properties, the efficiency of identifying oxygen-rich late/post-AGB stars could be improved.

  13. Summit Explosive Activity and Deformation: Constraints On The Etna SE Crater Through Tilt Variations During The 1998-2000 Lava Fountains

    NASA Astrophysics Data System (ADS)

    Bonaccorso, A.

    We investigate the relationships between the strain expected from the explosive action of a volcanic conduit, the paroxystic lava fountain events occurring recently at Etna, and the high precision continuous tilt signals recorded during such events with refer- ence to the ones occurring at the SE crater. Using both the inclusion and dislocation theories, it has been shown that the displacements expected from the explosive action of the volcanic conduits are defined by an equation which includes a term proportional to a line dilatation integral plus an integral that subtracts the effects proportional to a line of vertical double forces. Then, from these equations, it is possible to obtain the expected tilt. We conducted a comparison and an analysis with the tilt signals recorded at the Pizzi Deneri (PDN) volcanological observatory located in the high north-eastern flank of Mt. Etna. Here, an 80 m long-base mercury tiltmeter is installed along two partially underground tunnels. The instrument, utilising optical laser sensors for mea- suring the level changes at the extremities, is very stable with a real precision of 0.01 microradians. At the PDN distance from crater, as expected from the conduit theory, deformation effects can be very small and difficult to detect even if provoked by strong explosions. Nevertheless, in particular situations during the paroxystic activity of the June 24, 2000 (violent explosive phase with only 30 minutes duration, instrumental sampling of 1 data/minute) we recorded small (0.1-0.2 microradians) but very clear and significant tilt variations on the radial component. On the basis of the theoreti- cal equations, these variation allow us to fix constraints on the SE conduit geometry (diameter) and the characteristics of the surrounding medium (rigidity coefficient).

  14. Cellulases and coding sequences

    DOEpatents

    Li, Xin-Liang; Ljungdahl, Lars G.; Chen, Huizhong

    2001-01-01

    The present invention provides three fungal cellulases, their coding sequences, recombinant DNA molecules comprising the cellulase coding sequences, recombinant host cells and methods for producing same. The present cellulases are from Orpinomyces PC-2.

  15. Cellulases and coding sequences

    DOEpatents

    Li, Xin-Liang; Ljungdahl, Lars G.; Chen, Huizhong

    2001-02-20

    The present invention provides three fungal cellulases, their coding sequences, recombinant DNA molecules comprising the cellulase coding sequences, recombinant host cells and methods for producing same. The present cellulases are from Orpinomyces PC-2.

  16. Multiple Turbo Codes

    NASA Technical Reports Server (NTRS)

    Divsalar, D.; Pollara, F.

    1995-01-01

    A description is given of multiple turbo codes and a suitable decoder structure derived from an approximation to the maximum a posteriori probability (MAP) decision rule, which is substantially different from the decoder for two-code-based encoders.

  17. QR Code Mania!

    ERIC Educational Resources Information Center

    Shumack, Kellie A.; Reilly, Erin; Chamberlain, Nik

    2013-01-01

    space, has error-correction capacity, and can be read from any direction. These codes are used in manufacturing, shipping, and marketing, as well as in education. QR codes can be created to produce…

  18. STEEP32 computer code

    NASA Technical Reports Server (NTRS)

    Goerke, W. S.

    1972-01-01

    A manual is presented as an aid in using the STEEP32 code. The code is the EXEC 8 version of the STEEP code (STEEP is an acronym for shock two-dimensional Eulerian elastic plastic). The major steps in a STEEP32 run are illustrated in a sample problem. There is a detailed discussion of the internal organization of the code, including a description of each subroutine.

  19. Immunogenic properties of trivalent recombinant protein composed of B-subunits of LT, STX-2, and CT toxins.

    PubMed

    Kazemi, Rouhollah; Akhavian, Asal; Amani, Jafar; Salimian, Jafar; Motamedi, Mohammad-Javad; Mousavi, Amir; Jafari, Mahyat; Salmanian, Ali-Hatef

    2016-06-01

    Infectious diarrhoea remains an emerging problem in the world health program. Among diarrheagenic agents, Vibrio cholerae and enterotoxigenic and enterohemorrhagic Escherichia coli are critical enteropathogens. AB5 toxin produced by these bacteria, heat-labile enterotoxin (LT), cholera enterotoxin (CT), and shiga-like cytotoxin (STX) can target the immune system and are subunit vaccine candidates. A chemically-synthesized chimeric construct composed of the binding subunits of these toxins (LTB, STXB, and CTXB) was developed based on bioinformatics studies. The whole chimeric protein (rLSC) and each of the segments (rLTB, rSTXB, and rCTXB) were expressed in a prokaryotic expression system (E. coli), purified, and analysed for their immunogenic properties. The results indicate that these recombinant proteins were effectively able to present appropriate epitopes to an animal model of the immune system which could result in and increase IgG in serum and immune responses that protect against the binding activity of these toxins. The immunological assays revealed that the sera of immunized mice prevented toxins from binding to their specific receptors and neutralized their toxic effects. The proposed construct should be considered as a potent immunogen to prevent toxicity and diarrhoea. PMID:26970204

  20. Radiation pressure excitation of Low Temperature Atomic Force & Magnetic Force Microscope (LT-AFM/MFM) for Imaging

    NASA Astrophysics Data System (ADS)

    Karci, Ozgur; Celik, Umit; Oral, Ahmet; NanoMagnetics Instruments Ltd. Team; Middle East Tech Univ Team

    2015-03-01

    We describe a novel method for excitation of Atomic Force Microscope (AFM) cantilevers by means of radiation pressure for imaging in an AFM for the first time. Piezo excitation is the most common method for cantilever excitation, but it may cause spurious resonance peaks. A fiber optic interferometer with 1310 nm laser was used both to measure the deflection of cantilever and apply a force to the cantilever in a LT-AFM/MFM from NanoMagnetics Instruments. The laser power was modulated at the cantilever`s resonance frequency by a digital Phase Lock Loop (PLL). The force exerted by the radiation pressure on a perfectly reflecting surface by a laser beam of power P is F = 2P/c. We typically modulate the laser beam by ~ 800 μW and obtain 10nm oscillation amplitude with Q ~ 8,000 at 2.5x10-4 mbar. The cantilever's stiffness can be accurately calibrated by using the radiation pressure. We have demonstrated performance of the radiation pressure excitation in AFM/MFM by imaging a hard disk sample between 4-300K and Abrikosov vortex lattice in BSCCO single crystal at 4K to for the first time.

  1. Studies of Mn12-Ph Single Molecule Magnets by LT-STM and Modeling of Magnetic Stability Under Perturbation

    NASA Astrophysics Data System (ADS)

    Reaves, K.; Han, P.; Iwaya, K.; Hitosugi, T.; Packwood, D.; Katzgraber, H. G.; Zhao, H.; Dunbar, K. R.; Kim, K.; Teizer, W.

    2014-03-01

    We study Mn12O12(C6H5COO)16 (H2O)4 (Mn12-Ph) single-molecule magnets on a Cu(111) surface using low temperature scanning tunneling microscopy, LT-STM. We report the observation of Mn12-Ph in isolation and in thin films, deposited through vacuum spray deposition onto clean Cu(111). The local tunneling current observed within the molecular structure shows a strong bias voltage dependency, which is distinct from that of the Cu surface. Furthermore, we identify an internal inhomogeneity in the bias behavior within a single molecule. To further understand the stability of the magnetic properties of the molecules while on the surface, we develop a theoretical model to study the stability of the net magnetic moment under deformation of the spin-spin interaction graph. We develop a spin Hamiltonian-type model to predict magnetic moments that are intrinsically robust under random shape deformations to the spin-graph structure. This spin moment is shown to be a weak topological invariant for molecules with sufficiently many spin centers, approximately 20 to 50. We thank the WPI program for financial and research support.

  2. Pressure-temperature history of the Brooks Range and Seward Peninsula, Alaska HP-LT units and geodynamic implications

    NASA Astrophysics Data System (ADS)

    Lemonnier, N.; Labrousse, L.; Agard, P.; Till, A. B.

    2013-12-01

    Metamorphic rocks in the inner zones of mountain belts constitute a marker of vertical movements within orogenic wedges, themselves controled by balance between boundary conditions and volume forces. They provide key evidence for paleogeographic and tectonic reconstruction of convergence zones. In the Arctic, the Amerasian basin opened in cretaceous time and evolved in the upper plate of the Pacific subduction system. The tectonic evolution of the Brooks Range, northern Alaska, is a key issue for understanding possible coupling between these two dynamics. HP-LT metamorphic rocks, now exposed in the Schist belt, Brooks Range, and the Nome Complex, Seward Peninsula, were brought to the surface during Early Cretaceous to Paleocene time. The processes responsible for their exhumation (syn-collisional nappe-stacking or post-collisional extensional detachment) are still a matter of debate, and have direct implications in terms of orogenic boundary conditions and coupling between subduction processes (to the south) and basin response (to the north; the North Slope). Systematic thermometry via Raman Spectrometry (RSCM) on carbonaceous material from regional transects in the Schist Belt and the Seward Peninsula as well as pseudosections calculations allow the determination of units with contrasting pressure-temperature histories and a comparison of thermal evolution of the two areas. Geodynamic implications of their exhumation is then discussed.

  3. Purification of heavy metal loaded wastewater from electroplating industry under synthesis of delafossite (ABO2) by "Lt-delafossite process".

    PubMed

    John, Melanie; Heuss-Aßbichler, Soraya; Ullrich, Aladin; Rettenwander, Daniel

    2016-09-01

    In this study we present a new, environmental friendly and economic method, called Lt-delafossite process to treat industrial wastewater (initial Cu(2+)-concentrations of 1-15.6 g/l) by subsequent synthesis of nano-crystalline (doped) delafossite (CuFeO2) solely by precipitation and ageing at temperatures between 50 °C and 90 °C. The reached water purification rates are exclusively ≥99.99% for both wastewater models and wastewaters from electroplating industry. We succeeded to synthesize a mixture of 3R and 2H delafossite at 50 °C after 90 h and ≥70 °C after 16 h of ageing directly from industrial wastewater without any additional phases. In all cases green rust (GR), a Fe(II-III) layered double hydroxysulphate, Cu2O (cuprite) and Fe10O14(OH)2 (ferrihydrite) precipitates first. During ageing of the residues the metastable phases transform to delafossite. The residues are characterized by XRD, FTIR, SEM, TEM, VFTB and Mößbauer measurements. PMID:27179596

  4. Probing the structure-activity relationship of Escherichia coli LT-A by site-directed mutagenesis.

    PubMed

    Pizza, M; Domenighini, M; Hol, W; Giannelli, V; Fontana, M R; Giuliani, M M; Magagnoli, C; Peppoloni, S; Manetti, R; Rappuoli, R

    1994-10-01

    Computer analysis of the crystallographic structure of the A subunit of Escherichia coli heat-labile toxin (LT) was used to predict residues involved in NAD binding, catalysis and toxicity. Following site-directed mutagenesis, the mutants obtained could be divided into three groups. The first group contained fully assembled, non-toxic new molecules containing mutations of single amino acids such as Val-53-->Glu or Asp, Ser-63-->Lys, Val-97-->Lys, Tyr-104-->Lys or Asp, and Ser-114-->Lys or Glu. This group also included mutations in amino acids such as Arg-7, Glu-110 and Glu-112 that were already known to be important for enzymatic activity. The second group was formed by mutations that caused the collapse or prevented the assembly of the A subunit: Leu-41-->Phe, Ala-45-->Tyr or Glu, Val-53-->Tyr, Val-60-->Gly, Ser-68-->Pro, His-70-->Pro, Val-97-->Tyr and Ser-114-->Tyr. The third group contained those molecules that maintained a wild-type level of toxicity in spite of the mutations introduced: Arg-54-->Lys or Ala, Tyr-59-->Met, Ser-68-->Lys, Ala-72-->Arg, His or Asp and Arg-192-->Asn. The results provide a further understanding of the structure-function of the active site and new, non-toxic mutants that may be useful for the development of vaccines against diarrhoeal diseases. PMID:7830560

  5. Color code identification in coded structured light.

    PubMed

    Zhang, Xu; Li, Youfu; Zhu, Limin

    2012-08-01

    Color code is widely employed in coded structured light to reconstruct the three-dimensional shape of objects. Before determining the correspondence, a very important step is to identify the color code. Until now, the lack of an effective evaluation standard has hindered the progress in this unsupervised classification. In this paper, we propose a framework based on the benchmark to explore the new frontier. Two basic facets of the color code identification are discussed, including color feature selection and clustering algorithm design. First, we adopt analysis methods to evaluate the performance of different color features, and the order of these color features in the discriminating power is concluded after a large number of experiments. Second, in order to overcome the drawback of K-means, a decision-directed method is introduced to find the initial centroids. Quantitative comparisons affirm that our method is robust with high accuracy, and it can find or closely approach the global peak. PMID:22859022

  6. Software Certification - Coding, Code, and Coders

    NASA Technical Reports Server (NTRS)

    Havelund, Klaus; Holzmann, Gerard J.

    2011-01-01

    We describe a certification approach for software development that has been adopted at our organization. JPL develops robotic spacecraft for the exploration of the solar system. The flight software that controls these spacecraft is considered to be mission critical. We argue that the goal of a software certification process cannot be the development of "perfect" software, i.e., software that can be formally proven to be correct under all imaginable and unimaginable circumstances. More realistically, the goal is to guarantee a software development process that is conducted by knowledgeable engineers, who follow generally accepted procedures to control known risks, while meeting agreed upon standards of workmanship. We target three specific issues that must be addressed in such a certification procedure: the coding process, the code that is developed, and the skills of the coders. The coding process is driven by standards (e.g., a coding standard) and tools. The code is mechanically checked against the standard with the help of state-of-the-art static source code analyzers. The coders, finally, are certified in on-site training courses that include formal exams.

  7. XSOR codes users manual

    SciTech Connect

    Jow, Hong-Nian; Murfin, W.B.; Johnson, J.D.

    1993-11-01

    This report describes the source term estimation codes, XSORs. The codes are written for three pressurized water reactors (Surry, Sequoyah, and Zion) and two boiling water reactors (Peach Bottom and Grand Gulf). The ensemble of codes has been named ``XSOR``. The purpose of XSOR codes is to estimate the source terms which would be released to the atmosphere in severe accidents. A source term includes the release fractions of several radionuclide groups, the timing and duration of releases, the rates of energy release, and the elevation of releases. The codes have been developed by Sandia National Laboratories for the US Nuclear Regulatory Commission (NRC) in support of the NUREG-1150 program. The XSOR codes are fast running parametric codes and are used as surrogates for detailed mechanistic codes. The XSOR codes also provide the capability to explore the phenomena and their uncertainty which are not currently modeled by the mechanistic codes. The uncertainty distributions of input parameters may be used by an. XSOR code to estimate the uncertainty of source terms.

  8. DLLExternalCode

    SciTech Connect

    Greg Flach, Frank Smith

    2014-05-14

    DLLExternalCode is the a general dynamic-link library (DLL) interface for linking GoldSim (www.goldsim.com) with external codes. The overall concept is to use GoldSim as top level modeling software with interfaces to external codes for specific calculations. The DLLExternalCode DLL that performs the linking function is designed to take a list of code inputs from GoldSim, create an input file for the external application, run the external code, and return a list of outputs, read from files created by the external application, back to GoldSim. Instructions for creating the input file, running the external code, and reading the output are contained in an instructions file that is read and interpreted by the DLL.

  9. DLLExternalCode

    Energy Science and Technology Software Center (ESTSC)

    2014-05-14

    DLLExternalCode is the a general dynamic-link library (DLL) interface for linking GoldSim (www.goldsim.com) with external codes. The overall concept is to use GoldSim as top level modeling software with interfaces to external codes for specific calculations. The DLLExternalCode DLL that performs the linking function is designed to take a list of code inputs from GoldSim, create an input file for the external application, run the external code, and return a list of outputs, read frommore » files created by the external application, back to GoldSim. Instructions for creating the input file, running the external code, and reading the output are contained in an instructions file that is read and interpreted by the DLL.« less

  10. Development and preclinical evaluation of safety and immunogenicity of an oral ETEC vaccine containing inactivated E. coli bacteria overexpressing colonization factors CFA/I, CS3, CS5 and CS6 combined with a hybrid LT/CT B subunit antigen, administered alone and together with dmLT adjuvant.

    PubMed

    Holmgren, J; Bourgeois, L; Carlin, N; Clements, J; Gustafsson, B; Lundgren, A; Nygren, E; Tobias, J; Walker, R; Svennerholm, A-M

    2013-05-01

    A first-generation oral inactivated whole-cell enterotoxigenic Escherichia coli (ETEC) vaccine, comprising formalin-killed ETEC bacteria expressing different colonization factor (CF) antigens combined with cholera toxin B subunit (CTB), when tested in phase III studies did not significantly reduce overall (generally mild) ETEC diarrhea in travelers or children although it reduced more severe ETEC diarrhea in travelers by almost 80%. We have now developed a novel more immunogenic ETEC vaccine based on recombinant non-toxigenic E. coli strains engineered to express increased amounts of CF antigens, including CS6 as well as an ETEC-based B subunit protein (LCTBA), and the optional combination with a nontoxic double-mutant heat-labile toxin (LT) molecule (dmLT) as an adjuvant. Two test vaccines were prepared under GMP: (1) A prototype E. coli CFA/I-only formalin-killed whole-cell+LCTBA vaccine, and (2) A "complete" inactivated multivalent ETEC-CF (CFA/I, CS3, CS5 and CS6 antigens) whole-cell+LCTBA vaccine. These vaccines, when given intragastrically alone or together with dmLT in mice, were well tolerated and induced strong intestinal-mucosal IgA antibody responses as well as serum IgG and IgA responses to each of the vaccine CF antigens as well as to LT B subunit (LTB). Both mucosal and serum responses were further enhanced (adjuvanted) when the vaccines were co-administered with dmLT. We conclude that the new multivalent oral ETEC vaccine, both alone and especially in combination with the dmLT adjuvant, shows great promise for further testing in humans. PMID:23541621

  11. CFBDS J111807-064016: A new L/T transition brown dwarf in a binary system

    NASA Astrophysics Data System (ADS)

    Reylé, C.; Delorme, P.; Artigau, E.; Delfosse, X.; Albert, L.; Forveille, T.; Rajpurohit, A. S.; Allard, F.; Homeier, D.; Robin, A. C.

    2014-01-01

    Binary systems with a substellar companion are quite rare and provide interesting benchmarks. They constrain the complex physics of substellar atmospheres, because several physical parameters of the substellar secondary can be fixed from the much better characterized main-sequence primary. We report the discovery of CFBDS J111807-064016, a T2 brown-dwarf companion to 2MASS J111806.99-064007.8, a low-mass M4.5-M5 star. The brown dwarf was identified from the Canada France Brown Dwarf Survey. At a distance of 50-120 pc, the 7.7'' angular separation corresponds to projected separations of 390-900 AU. The primary displays no Hα emission, placing a lower limit on the age of the system of about 6 Gyr. The kinematics is also consistent with membership in the old thin disc. We obtained near-infrared spectra, which together with recent atmosphere models allow us to determine the effective temperature and gravity of the two components. We derived a system metallicity of [Fe/H] = -0.1 ± 0.1 using metallicity-sensitive absorption features in our medium-resolution Ks spectrum of the primary. From these parameters and the age constraint, evolutionary models estimate masses of 0.10 to 0.15 M⊙ for the M dwarf and 0.06 to 0.07 M⊙ for the T dwarf. This system is a particularly valuable benchmark because the brown dwarf belongs to the early-T class: the cloud-clearing that occurs at the L/T transition is very sensitive to gravity, metallicity, and detailed dust properties, and produces a large scatter in the colours. This T2 dwarf, with its metallicity measured from the primary and its mass and gravity much better constrained than those of younger early-Ts, will anchor our understanding of the colours of L/T transition brown dwarfs. It is also one of the most massive T dwarfs, just below the hydrogen-burning limit, and all this makes it a prime probe for brown-dwarf atmosphere and evolution models. Based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT

  12. Evolution of Enzymatic Activities int he Enolase Superfamily: L-Talarate/Galactarate Dehydratase from Salmonella typhimurium LT2

    SciTech Connect

    Yew,W.; Fedorov, A.; Fedorov, E.; Almo, S.; Gerlt, J.

    2007-01-01

    We assigned L-talarate dehydratase (TalrD) and galactarate dehydratase (GalrD) functions to a group of orthologous proteins in the mechanistically diverse enolase superfamily, focusing our characterization on the protein encoded by the Salmonella typhimurium LT2 genome (GI:16766982; STM3697). Like the homologous mandelate racemase, L-fuconate dehydratase, and D-tartrate dehydratase, the active site of TalrD/GalrD contains a general acid/base Lys 197 at the end of the second {beta}-strand in the ({beta}/{alpha}){sub 7}{beta}-barrel domain, Asp 226, Glu 252, and Glu 278 as ligands for the essential Mg{sup 2+} at the ends of the third, fourth, and fifth {sup {beta}}-strands, a general acid/base His 328-Asp 301 dyad at the ends of the seventh and sixth {beta}-strands, and an electrophilic Glu 348 at the end of the eighth {beta}-strand. We discovered the function of STM3697 by screening a library of acid sugars; it catalyzes the efficient dehydration of both L-talarate (k{sub cat} = 2.1 s{sup -1}, k{sub cat}/K{sub m} = 9.1 x 10{sup 3} M{sup -1} s{sup -1}) and galactarate (k{sub cat} = 3.5 s{sup -1}, k{sub cat}/K{sub m} = 1.1 x 10{sup 4} M{sup -1} s{sup -1}). Because L-talarate is a previously unknown metabolite, we demonstrated that S. typhimurium LT2 can utilize L-talarate as carbon source. Insertional disruption of the gene encoding STM3697 abolishes this phenotype; this disruption also diminishes, but does not eliminate, the ability of the organism to utilize galactarate as carbon source. The dehydration of L-talarate is accompanied by competing epimerization to galactarate; little epimerization to L-talarate is observed in the dehydration of galactarate. On the basis of (1) structures of the wild type enzyme complexed with L-lyxarohydroxamate, an analogue of the enolate intermediate, and of the K197A mutant complexed with L-glucarate, a substrate for exchange of the {alpha}-proton, and (2) incorporation of solvent deuterium into galactarate in competition with

  13. Cysteinyl leukotriene receptor (CysLT) antagonists decrease pentylenetetrazol-induced seizures and blood-brain barrier dysfunction.

    PubMed

    Lenz, Q F; Arroyo, D S; Temp, F R; Poersch, A B; Masson, C J; Jesse, A C; Marafiga, J R; Reschke, C R; Iribarren, P; Mello, C F

    2014-09-26

    Current evidence suggests that inflammation plays a role in the pathophysiology of seizures. In line with this view, selected pro-inflammatory arachidonic acid derivatives have been reported to facilitate seizures. Kainate-induced seizures are accompanied by leukotriene formation, and are reduced by inhibitors of LOX/COX pathway. Moreover, LTD4 receptor blockade and LTD4 synthesis inhibition suppress pentylenetetrazol (PTZ)-induced kindling and pilocarpine-induced recurrent seizures. Although there is convincing evidence supporting that blood-brain-barrier (BBB) dysfunction facilitates seizures, no study has investigated whether the anticonvulsant effect of montelukast is associated with its ability to maintain BBB integrity. In this study we investigated whether montelukast and other CysLT receptor antagonists decrease PTZ-induced seizures, as well as whether these antagonists preserve BBB during PTZ-induced seizures. Adult male albino Swiss mice were stereotaxically implanted with a cannula into the right lateral ventricle, and two electrodes were placed over the parietal cortex along with a ground lead positioned over the nasal sinus for electroencephalography (EEG) recording. The effects of montelukast (0.03 or 0.3 μmol/1 μL, i.c.v.), pranlukast (1 or 3 μmol/1 μL, i.c.v.), Bay u-9773 (0.3, 3 or 30 nmol/1 μL, i.c.v.), in the presence or absence of the agonist LTD4 (0.2, 2, 6 or 20 pmol/1 μL, i.c.v.), on PTZ (1.8 μmol/2 μL)-induced seizures and BBB permeability disruption were determined. The animals were injected with the antagonists, agonist or vehicle 30 min before PTZ, and monitored for additional 30 min for the appearance of seizures by electrographic and behavioral methods. BBB permeability was assessed by sodium fluorescein method and by confocal microscopy for CD45 and IgG immunoreactivity. Bay-u9973 (3 and 30 nmol), montelukast (0.03 and 0.3 μmol) and pranlukast (1 and 3 μmol), increased the latency to generalized seizures and decreased the

  14. Time course of apoptosis induced by photodynamic therapy with PsD007 in LT12 acute myeloid leukemia cells.

    PubMed

    Yin, Huijuan; Ye, Xuying; Niu, Qing; Wang, Chao; Li, Yingxin

    2016-07-01

    Apoptosis is one of the major mechanisms of photodynamic therapy (PDT) that leads to tumor degradation. Apoptosis-related genes and proteins function in a certain order and timing in the complex network of apoptosis. To further understanding of the apoptotic mechanism of PDT, this research examined the time course of apoptosis from PsD007 (a second-generation photosensitizer developed in China) induced PDT on the rat acute myeloid leukemia cell line LT12. MTT was used to detect the temporal dynamic of PDT killing effects and identified the "apoptotic window" of 2-24 h. Apoptosis showed a basal peak at 2 h, and the duration of apoptosis depended on PDT dose, which disappeared quickly at low concentrations but lasted to higher levels to 6 or 12 h at high concentrations as detected by flow cytometry. High-content imaging confirmed these results. An 84-gene apoptosis PCR array identified 15 genes with an expression level change of over twofold at 6 h post-PDT. Nine apoptosis-related genes showed changes in expression at 2-12 h after PDT. TNF family genes TNF and FASLG showed a maximal change of 3.47- and 4.42-fold from baseline. Key apoptosis proteins such as activated caspases showed strong up-regulation after PDT, with the expression peaks of cleaved caspase-7, caspase-9 and PARP at 4-6 h, and cleaved caspase-3 delayed to 6-12 h. Our findings help clarify the time course of apoptosis events in response to PDT treatment in a leukemia cell line and may help contribute to the clinical application of PDT in leukemia treatment. PMID:26861981

  15. The structures of Salmonella typhimurium LT2 neuraminidase and its complexes with three inhibitors at high resolution.

    PubMed

    Crennell, S J; Garman, E F; Philippon, C; Vasella, A; Laver, W G; Vimr, E R; Taylor, G L

    1996-06-01

    The structure of Salmonella typhimurium LT2 neuraminidase (STNA) is reported here to a resolution of 1.6 angstroms together with the structures of three complexes of STNA with different inhibitors. The first is 2-deoxy-2,3-dehydro-N-acetyl-neuraminic acid (Neu5Ac2en or DANA), the second and third are phosphonate derivatives of N-acetyl-neuraminic acid (NANA) which have phosphonate groups at the C2 position equatorial (ePANA) and axial (aPANA) to the plane of the sugar ring. The complex structures are at resolutions of 1.6 angstroms, 1.6 angstroms and 1.9 angstroms, respectively. These analyses show the STNA active site to be topologically inflexible and the interactions to be dominated by the arginine triad, with the pyranose rings of the inhibitors undergoing distortion to occupy the space available. Solvent structure differs only around the third phosphonate oxygen, which attracts a potassium ion. The STNA structure is topologically identical to the previously reported influenza virus neuraminidase structures, although very different in detail; the root-mean-square (r.m.s) deviation for 210 C alpha positions considered equivalent is 2.28 angstroms (out of a total of 390 residues in influenza and 381 in STNA). The active site residues are more highly conserved, in that both the viral and bacterial structures contain an arginine triad, a hydrophobic pocket, a tyrosine and glutamic acid residue at the base of the site and a potential proton-donating aspartic acid. However, differences in binding to O4 and to the glycerol side-chain may reflect the different kinetics employed by the two enzymes. PMID:8656428

  16. Raman evidence of the formation of LT-LiCoO 2 thin layers on NiO in molten carbonate at 650°C

    NASA Astrophysics Data System (ADS)

    Mendoza, L.; Baddour-Hadjean, R.; Cassir, M.; Pereira-Ramos, J. P.

    2004-03-01

    The structural evolution of thin layers of Co 3O 4 elaborated on nickel-based substrates in the Li 2CO 3-Na 2CO 3 carbonate eutectic at 650 °C as a function of time immersion is reported. Raman microspectrometry has been applied in order to provide more information on the nature of the protective cobalt oxide layers. The typical Raman fingerprint of the LT-LiCoO 2 compound has been obtained, with four well defined bands at 449, 484, 590 and 605 cm -1, while XRD data are unable to distinguish the layered phase (HT) from the spinel one (LT). The mechanical stability of such films does not exceed 10 h in direct contact with the molten carbonate bulk at 650 °C; nevertheless, these conditions are much more corrosive than in a molten carbonate fuel cell (MCFC).

  17. Measurement of the Polarized Structure Function sigma {sub LT'} for (p{rvec e},e'p) pi{sup 0} in the Delta (1232) Resonance Region

    SciTech Connect

    Kyungseon Joo; L.C. Smith; V.D. Burkert; R. Minehart

    2003-05-01

    The polarized longitudinal-transverse structure function {sigma}{sub LT'} has been measured for the first time in the {Delta}(1232) resonance region at Q{sup 2} = 0.40 and 0.65 GeV{sup 2}. Data for the p{rvec e},e'p {pi}{sup 0} reaction were taken at Jefferson Lab with the CEBAF Large Acceptance Spectrometer (CLAS) using longitudinally polarized electrons at an energy of 1.515 GeV. Evidence for interference between resonant and non-resonant amplitudes is discussed using a partial wave analysis. Comparison with previous beam asymmetry measurements at MAMI indicate a deviation from the predicted Q{sup 2} dependence of {sigma}{sub LT'} using recent phenomenological models.

  18. Comparison of continuous-wave terahertz wave generation and bias-field-dependent saturation in GaAs:O and LT-GaAs antennas.

    PubMed

    Chen, Kejian; Li, Yu-tai; Yang, Mong-huan; Cheung, Wing Yiu; Pan, Ci-Ling; Chan, Kam Tai

    2009-04-01

    Terahertz wave (THz) photoconductive (PC) antennas were fabricated on oxygen-implanted GaAs (GaAs:O) and low-temperature-grown GaAs (LT-GaAs). The measured cw THz power at 0.358 THz from the GaAs:O antenna is about twice that from the LT-GaAs antenna under the same testing conditions, with the former showing no saturation up to a bias of 40 kV/cm, while the latter is already beginning to saturate at 20 kV/cm. A modified theoretical model incorporating bias-field-dependent electron saturation velocity is employed to explain the results. It shows that GaAs:O exhibits a higher electron saturation velocity, which may be further exploited to generate even larger THz powers by reducing the ion dosage and optimizing the annealing process in GaAs:O. PMID:19340176

  19. Adaptive entropy coded subband coding of images.

    PubMed

    Kim, Y H; Modestino, J W

    1992-01-01

    The authors describe a design approach, called 2-D entropy-constrained subband coding (ECSBC), based upon recently developed 2-D entropy-constrained vector quantization (ECVQ) schemes. The output indexes of the embedded quantizers are further compressed by use of noiseless entropy coding schemes, such as Huffman or arithmetic codes, resulting in variable-rate outputs. Depending upon the specific configurations of the ECVQ and the ECPVQ over the subbands, many different types of SBC schemes can be derived within the generic 2-D ECSBC framework. Among these, the authors concentrate on three representative types of 2-D ECSBC schemes and provide relative performance evaluations. They also describe an adaptive buffer instrumented version of 2-D ECSBC, called 2-D ECSBC/AEC, for use with fixed-rate channels which completely eliminates buffer overflow/underflow problems. This adaptive scheme achieves performance quite close to the corresponding ideal 2-D ECSBC system. PMID:18296138

  20. Celecoxib and tauro-ursodeoxycholic acid co-treatment inhibits cell growth in familial adenomatous polyposis derived LT97 colon adenoma cells

    SciTech Connect

    Heumen, Bjorn W.H. van; Roelofs, Hennie M.J.; Morsche, Rene H.M. te; Marian, Brigitte; Nagengast, Fokko M.; Peters, Wilbert H.M.

    2012-04-15

    Chemoprevention would be a desirable strategy to avoid duodenectomy in patients with familial adenomatous polyposis (FAP) suffering from duodenal adenomatosis. We investigated the in vitro effects on cell proliferation, apoptosis, and COX-2 expression of the potential chemopreventives celecoxib and tauro-ursodeoxycholic acid (UDCA). HT-29 colon cancer cells and LT97 colorectal micro-adenoma cells derived from a patient with FAP, were exposed to low dose celecoxib and UDCA alone or in combination with tauro-cholic acid (CA) and tauro-chenodeoxycholic acid (CDCA), mimicking bile of FAP patients treated with UDCA. In HT-29 cells, co-treatment with low dose celecoxib and UDCA resulted in a decreased cell growth (14-17%, p < 0.01). A more pronounced decrease (23-27%, p < 0.01) was observed in LT97 cells. Cell growth of HT-29 cells exposed to 'artificial bile' enriched with UDCA, was decreased (p < 0.001), either in the absence or presence of celecoxib. In LT97 cells incubated with 'artificial bile' enriched with UDCA, cell growth was decreased only in the presence of celecoxib (p < 0.05). No clear evidence was found for involvement of proliferating cell nuclear antigen, caspase-3, or COX-2 in the cellular processes leading to the observed changes in cell growth. In conclusion, co-treatment with low dose celecoxib and UDCA has growth inhibitory effects on colorectal adenoma cells derived from a patient with FAP, and further research on this combination as promising chemopreventive strategy is desired. -- Highlights: Black-Right-Pointing-Pointer Celecoxib and UDCA acid co-treatment decreases cell growth in colon tumor cells. Black-Right-Pointing-Pointer UDCA enriched 'artificial bile' decreases LT-97 cell growth only in presence of celecoxib. Black-Right-Pointing-Pointer PCNA, caspase-3, nor COX-2 seem to be involved in the observed changes in cell growth.

  1. Analysis of Pulsating Components in the Eclipsing Binary Systems LT Herculis, RZ Microscopii, LY Puppis, V632 Scorpii, and V638 Scorpii

    NASA Astrophysics Data System (ADS)

    Streamer, M.; Bohlsen, T.; Ogmen, Y.

    2016-06-01

    Eclipsing binary stars are especially valuable for studies of stellar evolution. If pulsating components are also present then the stellar interior can be studied using asteroseismology techniques. We present photometric data and the analysis of the delta Scuti pulsations that we have discovered in five eclipsing binary systems. The systems are: LT Herculis, RZ Microscopii, LY Puppis, V632 Scorpii and V638 Scorpii. The dominant pulsation frequencies range between 13 - 29 cycles per day with semi-amplitudes of 4 - 20 millimagnitudes.

  2. A SEARCH FOR L/T TRANSITION DWARFS WITH Pan-STARRS1 AND WISE: DISCOVERY OF SEVEN NEARBY OBJECTS INCLUDING TWO CANDIDATE SPECTROSCOPIC VARIABLES

    SciTech Connect

    Best, William M. J.; Liu, Michael C.; Magnier, Eugene A.; Aller, Kimberly M.; Burgett, W. S.; Chambers, K. C.; Hodapp, K. W.; Kaiser, N.; Kudritzki, R.-P.; Morgan, J. S.; Tonry, J. L.; Wainscoat, R. J.; Deacon, Niall R.; Dupuy, Trent J.; Redstone, Joshua; Price, P. A.

    2013-11-10

    We present initial results from a wide-field (30,000 deg{sup 2}) search for L/T transition brown dwarfs within 25 pc using the Pan-STARRS1 and Wide-field Infrared Survey Explorer (WISE) surveys. Previous large-area searches have been incomplete for L/T transition dwarfs, because these objects are faint in optical bands and have near-infrared (near-IR) colors that are difficult to distinguish from background stars. To overcome these obstacles, we have cross-matched the Pan-STARRS1 (optical) and WISE (mid-IR) catalogs to produce a unique multi-wavelength database for finding ultracool dwarfs. As part of our initial discoveries, we have identified seven brown dwarfs in the L/T transition within 9-15 pc of the Sun. The L9.5 dwarf PSO J140.2308+45.6487 and the T1.5 dwarf PSO J307.6784+07.8263 (both independently discovered by Mace et al.) show possible spectroscopic variability at the Y and J bands. Two more objects in our sample show evidence of photometric J-band variability, and two others are candidate unresolved binaries based on their spectra. We expect our full search to yield a well-defined, volume-limited sample of L/T transition dwarfs that will include many new targets for study of this complex regime. PSO J307.6784+07.8263 in particular may be an excellent candidate for in-depth study of variability, given its brightness (J = 14.2 mag) and proximity (11 pc)

  3. Generating code adapted for interlinking legacy scalar code and extended vector code

    DOEpatents

    Gschwind, Michael K

    2013-06-04

    Mechanisms for intermixing code are provided. Source code is received for compilation using an extended Application Binary Interface (ABI) that extends a legacy ABI and uses a different register configuration than the legacy ABI. First compiled code is generated based on the source code, the first compiled code comprising code for accommodating the difference in register configurations used by the extended ABI and the legacy ABI. The first compiled code and second compiled code are intermixed to generate intermixed code, the second compiled code being compiled code that uses the legacy ABI. The intermixed code comprises at least one call instruction that is one of a call from the first compiled code to the second compiled code or a call from the second compiled code to the first compiled code. The code for accommodating the difference in register configurations is associated with the at least one call instruction.

  4. Representivity of incompletely sampled fall deposits in estimating eruption source parameters: a test using the 12-13 January 2011 lava fountain deposit from Mt. Etna volcano, Italy

    NASA Astrophysics Data System (ADS)

    Andronico, Daniele; Scollo, Simona; Cristaldi, Antonio; Lo Castro, Maria Deborah

    2014-10-01

    The Southeast Crater (SEC) of Mt. Etna, Italy, is renowned for its high activity, mainly long-lived eruptions consisting of sequences of individual paroxysmal episodes which have produced more than 150 eruptive events since 1998. Each episode typically forms eruption columns followed by tephra fallout over distances of up to about 100 km from the vent. One of the last sequences consisted of 25 lava fountaining events, which took place between January 2011 and April 2012 from a pit-vent on the eastern flank of the SEC and built a new scoria cone renamed New Southeast Crater. The first episode on 12-13 January 2011 produced tephra fallout which was unusually dispersed toward to the South extending out over the Mediterranean Sea. The southerly deposition of tephra permitted an extensive survey at distances between ~1 and ~100 km, providing an excellent characterization of the tephra deposit. Here, we document the stratigraphy of the 12-13 January fallout deposit, draw its dispersal, and reconstruct its isopleth map. These data are then used to estimate the main eruption source parameters. The total erupted mass (TEM) was calculated by using four different methodologies which give a mean value of 1.5 ± 0.4 × 108 kg. The mass eruption rate (MER) is 2.5 ± 0.7 × 104 kg/s using eruption duration of 100 min. The total grain-size (TGS) distribution, peaked at -3 phi, ranges between -5 and 5 phi and has a median value of -1.4 phi. Further, for the eruption column height, we obtained respective values of 6.8-13.8 km by using the method of Carey and Sparks (1986) and 3.4 ± 0.3 km by using the methods of Wilson and Walker 1987), Mastin et al. (2009), and Pistolesi et al. (2011) and considering the mean value of MER from the deposit. We also evaluated the uncertainty and reliability of TEM and TGS for scenarios where the proximal and distal samples are not obtainable. This is achieved by only using a sector spanning the downwind distances between 6 and 23 km. This scenario

  5. Mechanical code comparator

    DOEpatents

    Peter, Frank J.; Dalton, Larry J.; Plummer, David W.

    2002-01-01

    A new class of mechanical code comparators is described which have broad potential for application in safety, surety, and security applications. These devices can be implemented as micro-scale electromechanical systems that isolate a secure or otherwise controlled device until an access code is entered. This access code is converted into a series of mechanical inputs to the mechanical code comparator, which compares the access code to a pre-input combination, entered previously into the mechanical code comparator by an operator at the system security control point. These devices provide extremely high levels of robust security. Being totally mechanical in operation, an access control system properly based on such devices cannot be circumvented by software attack alone.

  6. Theory of epigenetic coding.

    PubMed

    Elder, D

    1984-06-01

    The logic of genetic control of development may be based on a binary epigenetic code. This paper revises the author's previous scheme dealing with the numerology of annelid metamerism in these terms. Certain features of the code had been deduced to be combinatorial, others not. This paradoxical contrast is resolved here by the interpretation that these features relate to different operations of the code; the combinatiorial to coding identity of units, the non-combinatorial to coding production of units. Consideration of a second paradox in the theory of epigenetic coding leads to a new solution which further provides a basis for epimorphic regeneration, and may in particular throw light on the "regeneration-duplication" phenomenon. A possible test of the model is also put forward. PMID:6748695

  7. Updating the Read Codes

    PubMed Central

    Robinson, David; Comp, Dip; Schulz, Erich; Brown, Philip; Price, Colin

    1997-01-01

    Abstract The Read Codes are a hierarchically-arranged controlled clinical vocabulary introduced in the early 1980s and now consisting of three maintained versions of differing complexity. The code sets are dynamic, and are updated quarterly in response to requests from users including clinicians in both primary and secondary care, software suppliers, and advice from a network of specialist healthcare professionals. The codes' continual evolution of content, both across and within versions, highlights tensions between different users and uses of coded clinical data. Internal processes, external interactions and new structural features implemented by the NHS Centre for Coding and Classification (NHSCCC) for user interactive maintenance of the Read Codes are described, and over 2000 items of user feedback episodes received over a 15-month period are analysed. PMID:9391934

  8. Imaging, single atom contact and single atom manipulations at low temperature using the new ScientaOmicron LT-UHV-4 STM

    NASA Astrophysics Data System (ADS)

    Yang, Jianshu; Sordes, Delphine; Kolmer, Marek; Martrou, David; Joachim, Christian

    2016-01-01

    The performances of the new ScientaOmicron LT-UHV 4-STM microscope have been certified by a series of state-of-art STM experiments on an Au(1 1 1) surface at 4.3 K. During the STM operation of the 4 STM scanners (independently or in parallel with an inter tip apex front to front distance down to a few tens of nanometers), a ΔZ stability of about 2 pm per STM was demonstrated. With this LT-UHV 4-STM stability, single Au atom manipulation experiments were performed on Au(1 1 1) by recording the pulling, sliding and pushing manipulation signals per scanner. Jump to contact experiments lead to perfectly linear low voltage I-V characteristics on a contacted single Au ad-atom with no need of averaging successive I-V's. Our results show how this new instrument is exactly 4 times a very precise single tip LT-UHV-STM. Two tips surface conductance measurements were performed on Au(1 1 1) using a lock-in technique in a floating sample mode of operation to capture the Au(1 1 1) surface states via two STM tips dI/dV characteristics.

  9. Reversal in Cognition Impairments, Cholinergic Dysfunction, and Cerebral Oxidative Stress Through the Modulation of Ryanodine Receptors (RyRs) and Cysteinyl Leukotriene-1 (CysLT1) Receptors.

    PubMed

    Singh, Prabhat; Sharma, Bhupesh

    2016-01-01

    Chronic cerebral hypoperfusion (CCH) is a general pathophysiological condition occurring in vascular dementia (VaD) associated with negative impact on cognitive functions. Ryanodine as well as cysteinyl leukotriene-1 receptors (RyRs and CysLT1Rs) are extensively present in the central nervous system, where they participate in regulation of cognition, motivation, inflammation and neurodegeneration. The purpose of this study is to examine the role of ruthenium red; a selective RyR blocker as well as montelukast; a specific CysLT1 antagonist in CCH induced VaD in mice. Two vessel occlusion (2VO) or permanent ligation of bilateral common carotid arteries technique was used to induce CCH in mice. Animals with bilateral carotid arteries occlusion have revealed impaired learning and memory (Morris water maze), cholinergic dysfunction (increased acetylcholinesterase activity) as well as increased brain oxidative stress (reduction in brain superoxide dismutase, glutathione and catalase with an increase in thiobarbituric acid reactive substance level), with increased brain infarct size (2,3,5-triphenylterazolium chloride staining). While, administration of ruthenium red and montelukast considerably attenuated CCH induced cognitive impairments, cholinergic dysfunction, brain oxidative stress as well as brain damage. The results suggest that bilateral carotid arteries occlusion induced CCH has brought out VaD, which was attenuated by treatment with ruthenium red and montelukast. Therefore, modulation of RyRs as well as CysLT1 receptors may provide help in conditions involving CCH such as cognitive impairment and VaD. PMID:26500103

  10. Effects of shoeing on limb movement and ground reaction forces in Icelandic horses at walk, tölt and trot.

    PubMed

    Waldern, Nina M; Wiestner, Thomas; Ramseier, Lea C; Amport, Claude; Weishaupt, Michael A

    2013-12-01

    lt is a symmetric four-beat gait with a speed range extending into that of trot and canter. Specific shoeing methods, such as unnaturally high and long hooves, are used to enforce individual gait predisposition. The aim of this study was to assess the consequences of this shoeing style on loading and movement of the limbs at walk, tölt and trot, and at different velocities. Simultaneous kinetic and kinematic gait analysis was carried out at walk (1.4m/s) and at two tölting and trotting speeds (3.3m/s and 3.9 m/s) on an instrumented treadmill. Thirteen sound Icelandic horses were first measured with high, long front hooves (SH) and, 1 week later, after trimming the hooves according to standard shoeing principles (SN). Comparing SH with SN, front hooves had 21 ± 5 mm longer dorsal hoof walls, and the shoeing material per hoof was 273 ± 50 g heavier. In all three gaits, gait quality, as it is currently judged, was improved with SH due to a lower stride rate, a longer stride length and a higher, but not wider, forelimb protraction arc, which were also positively associated with speed. Forelimb-hind limb balance remained unchanged, but limb impulses were higher. Apart from an increase of ≤ 2.2% in the forelimbs at the faster speed of both tölt and trot, SH had little influence on vertical peak forces. PMID:24360730

  11. AN INDEPENDENT ANALYSIS OF THE BROWN DWARF ATMOSPHERE MONITORING (BAM) DATA: LARGE-AMPLITUDE VARIABILITY IS RARE OUTSIDE THE L/T TRANSITION

    SciTech Connect

    Radigan, Jacqueline

    2014-12-20

    Observations of variability can provide valuable information about the processes of cloud formation and dissipation in brown dwarf atmospheres. Here we report the results of an independent analysis of archival data from the Brown dwarf Atmosphere Monitoring (BAM) program. Time series data for 14 L and T dwarfs reported to be significantly variable over timescales of hours were analyzed. We confirm large-amplitude variability (amplitudes >2%) for 4 out of 13 targets and place upper limits of 0.7%-1.6% on variability in the remaining sample. For two targets we find evidence of weak variability at amplitudes of 1.3% and 1.6%. Based on our revised classification of variable objects in the BAM study, we find strong variability outside the L/T transition to be rare at near infrared wavelengths. From a combined sample of 81 L0-T9 dwarfs from the revised BAM sample and the variability survey of Radigan et al., we infer an overall observed frequency for large-amplitude variability outside the L/T transition of 3.2{sub −1.8}{sup +2.8}%, in contrast to 24{sub −9}{sup +11}% for L9-T3.5 spectral types. We conclude that while strong variability is not limited to the L/T transition, it occurs more frequently in this spectral type range, indicative of larger or more highly contrasting cloud features at these spectral types.

  12. Doubled Color Codes

    NASA Astrophysics Data System (ADS)

    Bravyi, Sergey

    Combining protection from noise and computational universality is one of the biggest challenges in the fault-tolerant quantum computing. Topological stabilizer codes such as the 2D surface code can tolerate a high level of noise but implementing logical gates, especially non-Clifford ones, requires a prohibitively large overhead due to the need of state distillation. In this talk I will describe a new family of 2D quantum error correcting codes that enable a transversal implementation of all logical gates required for the universal quantum computing. Transversal logical gates (TLG) are encoded operations that can be realized by applying some single-qubit rotation to each physical qubit. TLG are highly desirable since they introduce no overhead and do not spread errors. It has been known before that a quantum code can have only a finite number of TLGs which rules out computational universality. Our scheme circumvents this no-go result by combining TLGs of two different quantum codes using the gauge-fixing method pioneered by Paetznick and Reichardt. The first code, closely related to the 2D color code, enables a transversal implementation of all single-qubit Clifford gates such as the Hadamard gate and the π / 2 phase shift. The second code that we call a doubled color code provides a transversal T-gate, where T is the π / 4 phase shift. The Clifford+T gate set is known to be computationally universal. The two codes can be laid out on the honeycomb lattice with two qubits per site such that the code conversion requires parity measurements for six-qubit Pauli operators supported on faces of the lattice. I will also describe numerical simulations of logical Clifford+T circuits encoded by the distance-3 doubled color code. Based on a joint work with Andrew Cross.

  13. Phonological coding during reading

    PubMed Central

    Leinenger, Mallorie

    2014-01-01

    The exact role that phonological coding (the recoding of written, orthographic information into a sound based code) plays during silent reading has been extensively studied for more than a century. Despite the large body of research surrounding the topic, varying theories as to the time course and function of this recoding still exist. The present review synthesizes this body of research, addressing the topics of time course and function in tandem. The varying theories surrounding the function of phonological coding (e.g., that phonological codes aid lexical access, that phonological codes aid comprehension and bolster short-term memory, or that phonological codes are largely epiphenomenal in skilled readers) are first outlined, and the time courses that each maps onto (e.g., that phonological codes come online early (pre-lexical) or that phonological codes come online late (post-lexical)) are discussed. Next the research relevant to each of these proposed functions is reviewed, discussing the varying methodologies that have been used to investigate phonological coding (e.g., response time methods, reading while eyetracking or recording EEG and MEG, concurrent articulation) and highlighting the advantages and limitations of each with respect to the study of phonological coding. In response to the view that phonological coding is largely epiphenomenal in skilled readers, research on the use of phonological codes in prelingually, profoundly deaf readers is reviewed. Finally, implications for current models of word identification (activation-verification model (Van Order, 1987), dual-route model (e.g., Coltheart, Rastle, Perry, Langdon, & Ziegler, 2001), parallel distributed processing model (Seidenberg & McClelland, 1989)) are discussed. PMID:25150679

  14. Phonological coding during reading.

    PubMed

    Leinenger, Mallorie

    2014-11-01

    The exact role that phonological coding (the recoding of written, orthographic information into a sound based code) plays during silent reading has been extensively studied for more than a century. Despite the large body of research surrounding the topic, varying theories as to the time course and function of this recoding still exist. The present review synthesizes this body of research, addressing the topics of time course and function in tandem. The varying theories surrounding the function of phonological coding (e.g., that phonological codes aid lexical access, that phonological codes aid comprehension and bolster short-term memory, or that phonological codes are largely epiphenomenal in skilled readers) are first outlined, and the time courses that each maps onto (e.g., that phonological codes come online early [prelexical] or that phonological codes come online late [postlexical]) are discussed. Next the research relevant to each of these proposed functions is reviewed, discussing the varying methodologies that have been used to investigate phonological coding (e.g., response time methods, reading while eye-tracking or recording EEG and MEG, concurrent articulation) and highlighting the advantages and limitations of each with respect to the study of phonological coding. In response to the view that phonological coding is largely epiphenomenal in skilled readers, research on the use of phonological codes in prelingually, profoundly deaf readers is reviewed. Finally, implications for current models of word identification (activation-verification model, Van Orden, 1987; dual-route model, e.g., M. Coltheart, Rastle, Perry, Langdon, & Ziegler, 2001; parallel distributed processing model, Seidenberg & McClelland, 1989) are discussed. PMID:25150679

  15. Bar Code Labels

    NASA Technical Reports Server (NTRS)

    1988-01-01

    American Bar Codes, Inc. developed special bar code labels for inventory control of space shuttle parts and other space system components. ABC labels are made in a company-developed anodizing aluminum process and consecutively marketed with bar code symbology and human readable numbers. They offer extreme abrasion resistance and indefinite resistance to ultraviolet radiation, capable of withstanding 700 degree temperatures without deterioration and up to 1400 degrees with special designs. They offer high resistance to salt spray, cleaning fluids and mild acids. ABC is now producing these bar code labels commercially or industrial customers who also need labels to resist harsh environments.

  16. MORSE Monte Carlo code

    SciTech Connect

    Cramer, S.N.

    1984-01-01

    The MORSE code is a large general-use multigroup Monte Carlo code system. Although no claims can be made regarding its superiority in either theoretical details or Monte Carlo techniques, MORSE has been, since its inception at ORNL in the late 1960s, the most widely used Monte Carlo radiation transport code. The principal reason for this popularity is that MORSE is relatively easy to use, independent of any installation or distribution center, and it can be easily customized to fit almost any specific need. Features of the MORSE code are described.

  17. Tokamak Systems Code

    SciTech Connect

    Reid, R.L.; Barrett, R.J.; Brown, T.G.; Gorker, G.E.; Hooper, R.J.; Kalsi, S.S.; Metzler, D.H.; Peng, Y.K.M.; Roth, K.E.; Spampinato, P.T.

    1985-03-01

    The FEDC Tokamak Systems Code calculates tokamak performance, cost, and configuration as a function of plasma engineering parameters. This version of the code models experimental tokamaks. It does not currently consider tokamak configurations that generate electrical power or incorporate breeding blankets. The code has a modular (or subroutine) structure to allow independent modeling for each major tokamak component or system. A primary benefit of modularization is that a component module may be updated without disturbing the remainder of the systems code as long as the imput to or output from the module remains unchanged.

  18. FAA Smoke Transport Code

    SciTech Connect

    Domino, Stefan; Luketa-Hanlin, Anay; Gallegos, Carlos

    2006-10-27

    FAA Smoke Transport Code, a physics-based Computational Fluid Dynamics tool, which couples heat, mass, and momentum transfer, has been developed to provide information on smoke transport in cargo compartments with various geometries and flight conditions. The software package contains a graphical user interface for specification of geometry and boundary conditions, analysis module for solving the governing equations, and a post-processing tool. The current code was produced by making substantial improvements and additions to a code obtained from a university. The original code was able to compute steady, uniform, isothermal turbulent pressurization. In addition, a preprocessor and postprocessor were added to arrive at the current software package.

  19. Expander chunked codes

    NASA Astrophysics Data System (ADS)

    Tang, Bin; Yang, Shenghao; Ye, Baoliu; Yin, Yitong; Lu, Sanglu

    2015-12-01

    Chunked codes are efficient random linear network coding (RLNC) schemes with low computational cost, where the input packets are encoded into small chunks (i.e., subsets of the coded packets). During the network transmission, RLNC is performed within each chunk. In this paper, we first introduce a simple transfer matrix model to characterize the transmission of chunks and derive some basic properties of the model to facilitate the performance analysis. We then focus on the design of overlapped chunked codes, a class of chunked codes whose chunks are non-disjoint subsets of input packets, which are of special interest since they can be encoded with negligible computational cost and in a causal fashion. We propose expander chunked (EC) codes, the first class of overlapped chunked codes that have an analyzable performance, where the construction of the chunks makes use of regular graphs. Numerical and simulation results show that in some practical settings, EC codes can achieve rates within 91 to 97 % of the optimum and outperform the state-of-the-art overlapped chunked codes significantly.

  20. Coding theory based models for protein translation initiation in prokaryotic organisms.

    SciTech Connect

    May, Elebeoba Eni; Bitzer, Donald L. (North Carolina State University, Raleigh, NC); Rosnick, David I. (North Carolina State University, Raleigh, NC); Vouk, Mladen A.

    2003-03-01

    Our research explores the feasibility of using communication theory, error control (EC) coding theory specifically, for quantitatively modeling the protein translation initiation mechanism. The messenger RNA (mRNA) of Escherichia coli K-12 is modeled as a noisy (errored), encoded signal and the ribosome as a minimum Hamming distance decoder, where the 16S ribosomal RNA (rRNA) serves as a template for generating a set of valid codewords (the codebook). We tested the E. coli based coding models on 5' untranslated leader sequences of prokaryotic organisms of varying taxonomical relation to E. coli including: Salmonella typhimurium LT2, Bacillus subtilis, and Staphylococcus aureus Mu50. The model identified regions on the 5' untranslated leader where the minimum Hamming distance values of translated mRNA sub-sequences and non-translated genomic sequences differ the most. These regions correspond to the Shine-Dalgarno domain and the non-random domain. Applying the EC coding-based models to B. subtilis, and S. aureus Mu50 yielded results similar to those for E. coli K-12. Contrary to our expectations, the behavior of S. typhimurium LT2, the more taxonomically related to E. coli, resembled that of the non-translated sequence group.

  1. LT-IIb(T13I), a non-toxic type II heat-labile enterotoxin, augments the capacity of a ricin toxin subunit vaccine to evoke neutralizing antibodies and protective immunity.

    PubMed

    Greene, Christopher J; Chadwick, Chrystal M; Mandell, Lorrie M; Hu, John C; O'Hara, Joanne M; Brey, Robert N; Mantis, Nicholas J; Connell, Terry D

    2013-01-01

    Currently, there is a shortage of adjuvants that can be employed with protein subunit vaccines to enhance protection against biological threats. LT-IIb(T13I) is an engineered nontoxic derivative of LT-IIb, a member of the type II subfamily of heat labile enterotoxins expressed by Escherichia coli, that possesses potent mucosal adjuvant properties. In this study we evaluated the capacity of LT-IIb(T13I) to augment the potency of RiVax, a recombinant ricin toxin A subunit vaccine, when co-administered to mice via the intradermal (i.d.) and intranasal (i.n.) routes. We report that co-administration of RiVax with LT-IIb(T13I) by the i.d. route enhanced the levels of RiVax-specific serum IgG antibodies (Ab) and elevated the ratio of ricin-neutralizing to non-neutralizing Ab, as compared to RiVax alone. Protection against a lethal ricin challenge was also augmented by LT-IIb(T13I). While local inflammatory responses elicited by LT-IIb(T13I) were comparable to those elicited by aluminum salts (Imject®), LT-IIb(T13I) was more effective than aluminum salts at augmenting production of RiVax-specific serum IgG. Finally, i.n. administration of RiVax with LT-IIb(T13I) also increased levels of RiVax-specific serum and mucosal Ab and enhanced protection against ricin challenge. Collectively, these data highlight the potential of LT-IIb(T13I) as an effective next-generation i.d., or possibly i.n. adjuvant for enhancing the immunogenicity of subunit vaccines for biodefense. PMID:23936344

  2. Simultaneous potential and circuit solution for 1D bounded plasma particle simulation codes

    SciTech Connect

    Verboncoeur, J.P.; Vahedi, V.; Birdsall, C.K. ); Alves, M.V. , S.J. dos Campos )

    1993-02-01

    A general second-order accurate method for solving the combined potential and circuit equations in a one-dimensional electrostatic bounded plasma PIC simulation is presented. The boundary conditions include surface charge on the electrodes, which are connected to a series RLC circuit with driving terms V(t) or l(t). The solution is obtained for planar, cylindrical, and spherical electrodes. The result is a tridiagonal matrix which is readily solved using well-known methods. The method is implemented in the codes PDPL (plasma device planar 1 D), PDC1 (cylindrical), and PDS1 (spherical).

  3. The power induced effects module: A FORTRAN code which estimates lift increments due to power induced effects for V/STOL flight

    NASA Technical Reports Server (NTRS)

    Sandlin, Doral R.; Howard, Kipp E.

    1991-01-01

    A user friendly FORTRAN code that can be used for preliminary design of V/STOL aircraft is described. The program estimates lift increments, due to power induced effects, encountered by aircraft in V/STOL flight. These lift increments are calculated using empirical relations developed from wind tunnel tests and are due to suckdown, fountain, ground vortex, jet wake, and the reaction control system. The code can be used as a preliminary design tool along with NASA Ames' Aircraft Synthesis design code or as a stand-alone program for V/STOL aircraft designers. The Power Induced Effects (PIE) module was validated using experimental data and data computed from lift increment routines. Results are presented for many flat plate models along with the McDonnell Aircraft Company's MFVT (mixed flow vectored thrust) V/STOL preliminary design and a 15 percent scale model of the YAV-8B Harrier V/STOL aircraft. Trends and magnitudes of lift increments versus aircraft height above the ground were predicted well by the PIE module. The code also provided good predictions of the magnitudes of lift increments versus aircraft forward velocity. More experimental results are needed to determine how well the code predicts lift increments as they vary with jet deflection angle and angle of attack. The FORTRAN code is provided in the appendix.

  4. Research on Universal Combinatorial Coding

    PubMed Central

    Lu, Jun; Zhang, Zhuo; Mo, Juan

    2014-01-01

    The conception of universal combinatorial coding is proposed. Relations exist more or less in many coding methods. It means that a kind of universal coding method is objectively existent. It can be a bridge connecting many coding methods. Universal combinatorial coding is lossless and it is based on the combinatorics theory. The combinational and exhaustive property make it closely related with the existing code methods. Universal combinatorial coding does not depend on the probability statistic characteristic of information source, and it has the characteristics across three coding branches. It has analyzed the relationship between the universal combinatorial coding and the variety of coding method and has researched many applications technologies of this coding method. In addition, the efficiency of universal combinatorial coding is analyzed theoretically. The multicharacteristic and multiapplication of universal combinatorial coding are unique in the existing coding methods. Universal combinatorial coding has theoretical research and practical application value. PMID:24772019

  5. Research on universal combinatorial coding.

    PubMed

    Lu, Jun; Zhang, Zhuo; Mo, Juan

    2014-01-01

    The conception of universal combinatorial coding is proposed. Relations exist more or less in many coding methods. It means that a kind of universal coding method is objectively existent. It can be a bridge connecting many coding methods. Universal combinatorial coding is lossless and it is based on the combinatorics theory. The combinational and exhaustive property make it closely related with the existing code methods. Universal combinatorial coding does not depend on the probability statistic characteristic of information source, and it has the characteristics across three coding branches. It has analyzed the relationship between the universal combinatorial coding and the variety of coding method and has researched many applications technologies of this coding method. In addition, the efficiency of universal combinatorial coding is analyzed theoretically. The multicharacteristic and multiapplication of universal combinatorial coding are unique in the existing coding methods. Universal combinatorial coding has theoretical research and practical application value. PMID:24772019

  6. DISCOVERY OF FOUR HIGH PROPER MOTION L DWARFS, INCLUDING A 10 pc L DWARF AT THE L/T TRANSITION {sup ,}

    SciTech Connect

    Castro, Philip J.; Gizis, John E.; Harris, Hugh C.; Mace, Gregory N.; McLean, Ian S.; Kirkpatrick, J. Davy; Pattarakijwanich, Petchara; Skrutskie, Michael F. E-mail: gizis@udel.edu

    2013-10-20

    We discover four high proper motion L dwarfs by comparing the Wide-field Infrared Survey Explorer (WISE) to the Two Micron All Sky Survey. WISE J140533.32+835030.5 is an L dwarf at the L/T transition with a proper motion of 0.85 ± 0.''02 yr{sup –1}, previously overlooked due to its proximity to a bright star (V ≈ 12 mag). From optical spectroscopy we find a spectral type of L8, and from moderate-resolution J band spectroscopy we find a near-infrared spectral type of L9. We find WISE J140533.32+835030.5 to have a distance of 9.7 ± 1.7 pc, bringing the number of L dwarfs at the L/T transition within 10 pc from six to seven. WISE J040137.21+284951.7, WISE J040418.01+412735.6, and WISE J062442.37+662625.6 are all early L dwarfs within 25 pc, and were classified using optical and low-resolution near-infrared spectra. WISE J040418.01+412735.6 is an L2 pec (red) dwarf, a member of the class of unusually red L dwarfs. We use follow-up optical and low-resolution near-infrared spectroscopy to classify a previously discovered fifth object WISEP J060738.65+242953.4 as an (L8 Opt/L9 NIR), confirming it as an L dwarf at the L/T transition within 10 pc. WISEP J060738.65+242953.4 shows tentative CH{sub 4} in the H band, possibly the result of unresolved binarity with an early T dwarf, a scenario not supported by binary spectral template fitting. If WISEP J060738.65+242953.4 is a single object, it represents the earliest onset of CH{sub 4} in the H band of an L/T transition dwarf in the SpeX Library. As very late L dwarfs within 10 pc, WISE J140533.32+835030.5 and WISEP J060738.65+242953.4 will play a vital role in resolving outstanding issues at the L/T transition.

  7. Fast Coding Unit Encoding Mechanism for Low Complexity Video Coding

    PubMed Central

    Wu, Yueying; Jia, Kebin; Gao, Guandong

    2016-01-01

    In high efficiency video coding (HEVC), coding tree contributes to excellent compression performance. However, coding tree brings extremely high computational complexity. Innovative works for improving coding tree to further reduce encoding time are stated in this paper. A novel low complexity coding tree mechanism is proposed for HEVC fast coding unit (CU) encoding. Firstly, this paper makes an in-depth study of the relationship among CU distribution, quantization parameter (QP) and content change (CC). Secondly, a CU coding tree probability model is proposed for modeling and predicting CU distribution. Eventually, a CU coding tree probability update is proposed, aiming to address probabilistic model distortion problems caused by CC. Experimental results show that the proposed low complexity CU coding tree mechanism significantly reduces encoding time by 27% for lossy coding and 42% for visually lossless coding and lossless coding. The proposed low complexity CU coding tree mechanism devotes to improving coding performance under various application conditions. PMID:26999741

  8. Pseudomorphs of Neotethyan Evaporites in Anatolia's HP/LT belts - Aptian basin-wide pelagic gypsum deposits

    NASA Astrophysics Data System (ADS)

    Scheffler, Franziska; Oberhänsli, Roland; Pourteau, Amaury; Immenhauser, Adrian; Candan, Osman

    2015-04-01

    Rosetta Marble was defined in SW Anatolia as 3D-radiating textures of dm-to-m-long calcite rods in the HP/LT metamorphosed Mid-Cretaceous pelagic carbonate sequence of the Ören Unit. Rosetta Marble in the type locality are interbedded with meta-chert beds, and may constitute entire carbonate beds. Rare aragonite relicts and Sr-rich, fibrous calcite pseudomorphs after aragonite witness the HP metamorphic imprint of this sequence during the closure of a Neotethyan oceanic domain during latest Cretaceous-Palaeocene times. We investigated the Rosetta Marble of the Ören Unit, as well as other known and newly found localities in the Tavşanlı and Afyon zones, and the Alanya Massif and Malatya area, to decipher the metamorphic, diagenetic and sedimentologic significance of these uncommon textures. Based on field, petrographic and geochemical investigations, we document a wide variety of Rosetta-type textures. A striking resemblance with well-known gypsum morphologies (e.g. shallow-tail, palm-tree textures) leads us to argue that Rosetta Marble was initially composed of giant gypsum crystals (selenite). The absence of anhydrite relicts of pseudomorphs indicate that gypsum transformed into calcite soon after the deposition by the mean of a sulphate reduction reaction. The gypsum-to-calcite transformation requires that organic matter intervened as a reactant phase. Mid Cretaceous oceanic domains in the Tethyan realm are characterised by overall anoxic conditions that allowed the preservation of organic material. Rosetta Marble exposures are widely distributed over 600 km along the Neotethyan suture zone. During deepening of the Neotethyan ocean in Mid Cretaceous times, basin-wide and cyclic sedimentation of gypsum and radiolarite occurred. The origin of high-salinity waters needed for gypsum precipitation was located at shelf levels. Density and gravity effects forced the brines to cascade downwards into the deep ocean. Favorable climatic conditions trigger the formation

  9. Synthesizing Certified Code

    NASA Technical Reports Server (NTRS)

    Whalen, Michael; Schumann, Johann; Fischer, Bernd

    2002-01-01

    Code certification is a lightweight approach to demonstrate software quality on a formal level. Its basic idea is to require producers to provide formal proofs that their code satisfies certain quality properties. These proofs serve as certificates which can be checked independently. Since code certification uses the same underlying technology as program verification, it also requires many detailed annotations (e.g., loop invariants) to make the proofs possible. However, manually adding theses annotations to the code is time-consuming and error-prone. We address this problem by combining code certification with automatic program synthesis. We propose an approach to generate simultaneously, from a high-level specification, code and all annotations required to certify generated code. Here, we describe a certification extension of AUTOBAYES, a synthesis tool which automatically generates complex data analysis programs from compact specifications. AUTOBAYES contains sufficient high-level domain knowledge to generate detailed annotations. This allows us to use a general-purpose verification condition generator to produce a set of proof obligations in first-order logic. The obligations are then discharged using the automated theorem E-SETHEO. We demonstrate our approach by certifying operator safety for a generated iterative data classification program without manual annotation of the code.

  10. Lichenase and coding sequences

    DOEpatents

    Li, Xin-Liang; Ljungdahl, Lars G.; Chen, Huizhong

    2000-08-15

    The present invention provides a fungal lichenase, i.e., an endo-1,3-1,4-.beta.-D-glucanohydrolase, its coding sequence, recombinant DNA molecules comprising the lichenase coding sequences, recombinant host cells and methods for producing same. The present lichenase is from Orpinomyces PC-2.

  11. Codes of Conduct

    ERIC Educational Resources Information Center

    Million, June

    2004-01-01

    Most schools have a code of conduct, pledge, or behavioral standards, set by the district or school board with the school community. In this article, the author features some schools that created a new vision of instilling code of conducts to students based on work quality, respect, safety and courtesy. She suggests that communicating the code…

  12. Code of Ethics

    ERIC Educational Resources Information Center

    Division for Early Childhood, Council for Exceptional Children, 2009

    2009-01-01

    The Code of Ethics of the Division for Early Childhood (DEC) of the Council for Exceptional Children is a public statement of principles and practice guidelines supported by the mission of DEC. The foundation of this Code is based on sound ethical reasoning related to professional practice with young children with disabilities and their families…

  13. Legacy Code Modernization

    NASA Technical Reports Server (NTRS)

    Hribar, Michelle R.; Frumkin, Michael; Jin, Haoqiang; Waheed, Abdul; Yan, Jerry; Saini, Subhash (Technical Monitor)

    1998-01-01

    Over the past decade, high performance computing has evolved rapidly; systems based on commodity microprocessors have been introduced in quick succession from at least seven vendors/families. Porting codes to every new architecture is a difficult problem; in particular, here at NASA, there are many large CFD applications that are very costly to port to new machines by hand. The LCM ("Legacy Code Modernization") Project is the development of an integrated parallelization environment (IPE) which performs the automated mapping of legacy CFD (Fortran) applications to state-of-the-art high performance computers. While most projects to port codes focus on the parallelization of the code, we consider porting to be an iterative process consisting of several steps: 1) code cleanup, 2) serial optimization,3) parallelization, 4) performance monitoring and visualization, 5) intelligent tools for automated tuning using performance prediction and 6) machine specific optimization. The approach for building this parallelization environment is to build the components for each of the steps simultaneously and then integrate them together. The demonstration will exhibit our latest research in building this environment: 1. Parallelizing tools and compiler evaluation. 2. Code cleanup and serial optimization using automated scripts 3. Development of a code generator for performance prediction 4. Automated partitioning 5. Automated insertion of directives. These demonstrations will exhibit the effectiveness of an automated approach for all the steps involved with porting and tuning a legacy code application for a new architecture.

  14. Modified JPEG Huffman coding.

    PubMed

    Lakhani, Gopal

    2003-01-01

    It is a well observed characteristic that when a DCT block is traversed in the zigzag order, the AC coefficients generally decrease in size and the run-length of zero coefficients increase in number. This article presents a minor modification to the Huffman coding of the JPEG baseline compression algorithm to exploit this redundancy. For this purpose, DCT blocks are divided into bands so that each band can be coded using a separate code table. Three implementations are presented, which all move the end-of-block marker up in the middle of DCT block and use it to indicate the band boundaries. Experimental results are presented to compare reduction in the code size obtained by our methods with the JPEG sequential-mode Huffman coding and arithmetic coding methods. The average code reduction to the total image code size of one of our methods is 4%. Our methods can also be used for progressive image transmission and hence, experimental results are also given to compare them with two-, three-, and four-band implementations of the JPEG spectral selection method. PMID:18237897

  15. Binary concatenated coding system

    NASA Technical Reports Server (NTRS)

    Monford, L. G., Jr.

    1973-01-01

    Coding, using 3-bit binary words, is applicable to any measurement having integer scale up to 100. System using 6-bit data words can be expanded to read from 1 to 10,000, and 9-bit data words can increase range to 1,000,000. Code may be ''read'' directly by observation after memorizing simple listing of 9's and 10's.

  16. Computerized mega code recording.

    PubMed

    Burt, T W; Bock, H C

    1988-04-01

    A system has been developed to facilitate recording of advanced cardiac life support mega code testing scenarios. By scanning a paper "keyboard" using a bar code wand attached to a portable microcomputer, the person assigned to record the scenario can easily generate an accurate, complete, timed, and typewritten record of the given situations and the obtained responses. PMID:3354937

  17. Coding for optical channels

    NASA Technical Reports Server (NTRS)

    Baumert, L. D.; Mceliece, R. J.; Rumsey, H., Jr.

    1979-01-01

    In a previous paper Pierce considered the problem of optical communication from a novel viewpoint, and concluded that performance will likely be limited by issues of coding complexity rather than by thermal noise. This paper reviews the model proposed by Pierce and presents some results on the analysis and design of codes for this application.

  18. Combustion chamber analysis code

    NASA Technical Reports Server (NTRS)

    Przekwas, A. J.; Lai, Y. G.; Krishnan, A.; Avva, R. K.; Giridharan, M. G.

    1993-01-01

    A three-dimensional, time dependent, Favre averaged, finite volume Navier-Stokes code has been developed to model compressible and incompressible flows (with and without chemical reactions) in liquid rocket engines. The code has a non-staggered formulation with generalized body-fitted-coordinates (BFC) capability. Higher order differencing methodologies such as MUSCL and Osher-Chakravarthy schemes are available. Turbulent flows can be modeled using any of the five turbulent models present in the code. A two-phase, two-liquid, Lagrangian spray model has been incorporated into the code. Chemical equilibrium and finite rate reaction models are available to model chemically reacting flows. The discrete ordinate method is used to model effects of thermal radiation. The code has been validated extensively against benchmark experimental data and has been applied to model flows in several propulsion system components of the SSME and the STME.

  19. Energy Conservation Code Decoded

    SciTech Connect

    Cole, Pam C.; Taylor, Zachary T.

    2006-09-01

    Designing an energy-efficient, affordable, and comfortable home is a lot easier thanks to a slime, easier to read booklet, the 2006 International Energy Conservation Code (IECC), published in March 2006. States, counties, and cities have begun reviewing the new code as a potential upgrade to their existing codes. Maintained under the public consensus process of the International Code Council, the IECC is designed to do just what its title says: promote the design and construction of energy-efficient homes and commercial buildings. Homes in this case means traditional single-family homes, duplexes, condominiums, and apartment buildings having three or fewer stories. The U.S. Department of Energy, which played a key role in proposing the changes that resulted in the new code, is offering a free training course that covers the residential provisions of the 2006 IECC.

  20. Astrophysics Source Code Library

    NASA Astrophysics Data System (ADS)

    Allen, A.; DuPrie, K.; Berriman, B.; Hanisch, R. J.; Mink, J.; Teuben, P. J.

    2013-10-01

    The Astrophysics Source Code Library (ASCL), founded in 1999, is a free on-line registry for source codes of interest to astronomers and astrophysicists. The library is housed on the discussion forum for Astronomy Picture of the Day (APOD) and can be accessed at http://ascl.net. The ASCL has a comprehensive listing that covers a significant number of the astrophysics source codes used to generate results published in or submitted to refereed journals and continues to grow. The ASCL currently has entries for over 500 codes; its records are citable and are indexed by ADS. The editors of the ASCL and members of its Advisory Committee were on hand at a demonstration table in the ADASS poster room to present the ASCL, accept code submissions, show how the ASCL is starting to be used by the astrophysics community, and take questions on and suggestions for improving the resource.

  1. Mentoring: dentistry's fountain of youth.

    PubMed

    Certosimo, Fred

    2014-01-01

    A mentor's principal purpose is to help develop the qualities that another individual (protégé or mentee) needs to attain his or her professional goals. Mentors provide their protege with knowledge, advice, counsel, support, and the opportunity to better position themselves to attain success in the dental profession. They help their mentee's "learn the ropes" and attain the wisdom only a seasoned veteran can pass along about the fundamental assumptions and values of a profession's culture. Mentoring is not a science, but an art-it is often important not merely knowing what to say, but how and when to say it. The mentor and the mentee have different professional goals, and to compound the relationship, both present with varied life experiences and in many cases, from diverse cultures. Wise mentors must be sensitive to the individuality of their protege and offer wisdom, judgment, resilience, and independence in a custom-tailored manner. Lastly, mentoring is not professional therapy and counseling. Mentors are different from role models. However, despite the many opportunities and potential setbacks, if done properly, the benefits of the mentoring relationship can last a lifetime for both the mentor and the mentee. PMID:25080671

  2. Mentoring: dentistry's fountain of youth.

    PubMed

    Certosimo, Fred

    2014-09-01

    A mentor's principal purpose is to help develop the qualities that another individual (protégé or mentee) needs to attain his or her professional goals. Mentors provide their protégés with knowledge, advice, counsel, support, and the opportunity to better position themselves to attain success in the dental profession. They help their mentees "learn the ropes" and attain the wisdom only a seasoned veteran can pass along about the fundamental assumptions and values of a profession's culture. Mentoring is not a science, but an art--it is often important not merely knowing what to say, but how and when to say it. The mentor and the mentee have different professional goals and, to compound the relationship, both present with varied life experiences and, in many cases, from diverse cultures. Wise mentors must be sensitive to the individuality of their protégés and offer wisdom, judgment, resilience, and independence in a custom-tailored manner. Lastly, mentoring is not professional therapy and counseling. Mentors are different from role models. However, despite the many opportunities and potential setbacks, if done properly, the benefits of the mentoring relationship can last a lifetime for both the mentor and the mentee. PMID:25306827

  3. Quantum convolutional codes derived from constacyclic codes

    NASA Astrophysics Data System (ADS)

    Yan, Tingsu; Huang, Xinmei; Tang, Yuansheng

    2014-12-01

    In this paper, three families of quantum convolutional codes are constructed. The first one and the second one can be regarded as a generalization of Theorems 3, 4, 7 and 8 [J. Chen, J. Li, F. Yang and Y. Huang, Int. J. Theor. Phys., doi:10.1007/s10773-014-2214-6 (2014)], in the sense that we drop the constraint q ≡ 1 (mod 4). Furthermore, the second one and the third one attain the quantum generalized Singleton bound.

  4. Huffman coding in advanced audio coding standard

    NASA Astrophysics Data System (ADS)

    Brzuchalski, Grzegorz

    2012-05-01

    This article presents several hardware architectures of Advanced Audio Coding (AAC) Huffman noiseless encoder, its optimisations and working implementation. Much attention has been paid to optimise the demand of hardware resources especially memory size. The aim of design was to get as short binary stream as possible in this standard. The Huffman encoder with whole audio-video system has been implemented in FPGA devices.

  5. Coded aperture computed tomography

    NASA Astrophysics Data System (ADS)

    Choi, Kerkil; Brady, David J.

    2009-08-01

    Diverse physical measurements can be modeled by X-ray transforms. While X-ray tomography is the canonical example, reference structure tomography (RST) and coded aperture snapshot spectral imaging (CASSI) are examples of physically unrelated but mathematically equivalent sensor systems. Historically, most x-ray transform based systems sample continuous distributions and apply analytical inversion processes. On the other hand, RST and CASSI generate discrete multiplexed measurements implemented with coded apertures. This multiplexing of coded measurements allows for compression of measurements from a compressed sensing perspective. Compressed sensing (CS) is a revelation that if the object has a sparse representation in some basis, then a certain number, but typically much less than what is prescribed by Shannon's sampling rate, of random projections captures enough information for a highly accurate reconstruction of the object. This paper investigates the role of coded apertures in x-ray transform measurement systems (XTMs) in terms of data efficiency and reconstruction fidelity from a CS perspective. To conduct this, we construct a unified analysis using RST and CASSI measurement models. Also, we propose a novel compressive x-ray tomography measurement scheme which also exploits coding and multiplexing, and hence shares the analysis of the other two XTMs. Using this analysis, we perform a qualitative study on how coded apertures can be exploited to implement physical random projections by "regularizing" the measurement systems. Numerical studies and simulation results demonstrate several examples of the impact of coding.

  6. Report number codes

    SciTech Connect

    Nelson, R.N.

    1985-05-01

    This publication lists all report number codes processed by the Office of Scientific and Technical Information. The report codes are substantially based on the American National Standards Institute, Standard Technical Report Number (STRN)-Format and Creation Z39.23-1983. The Standard Technical Report Number (STRN) provides one of the primary methods of identifying a specific technical report. The STRN consists of two parts: The report code and the sequential number. The report code identifies the issuing organization, a specific program, or a type of document. The sequential number, which is assigned in sequence by each report issuing entity, is not included in this publication. Part I of this compilation is alphabetized by report codes followed by issuing installations. Part II lists the issuing organization followed by the assigned report code(s). In both Parts I and II, the names of issuing organizations appear for the most part in the form used at the time the reports were issued. However, for some of the more prolific installations which have had name changes, all entries have been merged under the current name.

  7. Toxicity and immunogenicity of Enterotoxigenic Escherichia coli heat-labile and heat-stable toxoid fusion 3xSTa(A14Q)-LT(S63K/R192G/L211A) in a murine model.

    PubMed

    Zhang, Chengxian; Knudsen, David E; Liu, Mei; Robertson, Donald C; Zhang, Weiping

    2013-01-01

    Diarrhea is the second leading cause of death to young children. Enterotoxigenic Escherichia coli (ETEC) are the most common bacteria causing diarrhea. Adhesins and enterotoxins are the virulence determinants in ETEC diarrhea. Adhesins mediate bacterial attachment and colonization, and enterotoxins including heat-labile (LT) and heat-stable type Ib toxin (STa) disrupt fluid homeostasis in host cells that leads to fluid hyper-secretion and diarrhea. Thus, adhesins and enterotoxins have been primarily targeted in ETEC vaccine development. A recent study reported toxoid fusions with STa toxoid (STa(P13F)) fused at the N- or C-terminus, or inside the A subunit of LT(R192G) elicited neutralizing antitoxin antibodies, and suggested application of toxoid fusions in ETEC vaccine development (Liu et al., Infect. Immun. 79:4002-4009, 2011). In this study, we generated a different STa toxoid (STa(A14Q)) and a triple-mutant LT toxoid (LT(S63K/R192G/L211A), tmLT), constructed a toxoid fusion (3xSTa(A14Q)-tmLT) that carried 3 copies of STa(A14Q) for further facilitation of anti-STa immunogenicity, and assessed antigen safety and immunogenicity in a murine model to explore its potential for ETEC vaccine development. Mice immunized with this fusion antigen showed no adverse effects, and developed antitoxin antibodies particularly through the IP route. Anti-LT antibodies were detected and were shown neutralizing against CT in vitro. Anti-STa antibodies were also detected in the immunized mice, and serum from the IP immunized mice neutralized STa toxin in vitro. Data from this study indicated that toxoid fusion 3xSTa(A14Q)-tmLT is safe and can induce neutralizing antitoxin antibodies, and provided helpful information for vaccine development against ETEC diarrhea. PMID:24146989

  8. Cysteinyl-leukotrienes are released from astrocytes and increase astrocyte proliferation and glial fibrillary acidic protein via cys-LT1 receptors and mitogen-activated protein kinase pathway.

    PubMed

    Ciccarelli, Renata; D'Alimonte, Iolanda; Santavenere, Clara; D'Auro, Mariagrazia; Ballerini, Patrizia; Nargi, Eleonora; Buccella, Silvana; Nicosia, Simonetta; Folco, Giancarlo; Caciagli, Francesco; Di Iorio, Patrizia

    2004-09-01

    Cysteinyl-leukotrienes (cys-LTs), potent mediators in inflammatory diseases, are produced by nervous tissue, but their cellular source and role in the brain are not very well known. In this report we have demonstrated that rat cultured astrocytes express the enzymes (5'-lipoxygenase and LTC(4) synthase) required for cys-LT production, and release cys-LTs in resting condition and, to a greater extent, in response to calcium ionophore A23187, 1 h combined oxygen-glucose deprivation or 2-methyl-thioATP, a selective P2Y(1)/ATP receptor agonist. MK-886, a LT synthesis inhibitor, prevented basal and evoked cys-LT release. In addition, 2-methyl-thioATP-induced cys-LT release was abolished by suramin, a P2 receptor antagonist, or by inhibitors of ATP binding cassette proteins involved in cys-LT release. We also showed that astrocytes express cys-LT(1) and not cys-LT(2) receptors. The stimulation of these receptors by LTD(4) activated the mitogen-activated protein kinase (MAPK) pathway. This effect was: (i) insensitive to inhibitors of receptor-coupled Gi protein (pertussis toxin) or tyrosine kinase receptors (genistein); (ii) abolished by MK-571, a cys-LT(1) selective receptor antagonist, or PD98059, a MAPK inhibitor; (iii) reduced by inhibitors of calcium/calmodulin-dependent kinase II (KN-93), Ca(2+)-dependent and -independent (GF102903X) or Ca(2+)-dependent (Gö6976) protein kinase C isoforms. LTD(4) also increased astrocyte proliferation and glial fibrillary acidic protein content, which are considered hallmarks of reactive astrogliosis. Both effects were counteracted by cell pretreatment with MK-571 or PD98059. Thus, cys-LTs released from astrocytes might play an autocrine role in the induction of reactive astrogliosis that, in brain injuries, contributes to the formation of a reparative glial scar. PMID:15355318

  9. TRANSF code user manual

    SciTech Connect

    Weaver, H.J.

    1981-11-01

    The TRANSF code is a semi-interactive FORTRAN IV program which is designed to calculate the model parameters of a (structural) system by performing a least square parameter fit to measured transfer function data. The code is available at LLNL on both the 7600 and the Cray machines. The transfer function data to be fit is read into the code via a disk file. The primary mode of output is FR80 graphics, although, it is also possible to have results written to either the TTY or to a disk file.

  10. Quantitative transfer of Salmonella Typhimurium LT2 during mechanical slicing of tomatoes as impacted by multiple processing variables.

    PubMed

    Wang, Haiqiang; Ryser, Elliot T

    2016-10-01

    Slicing of fresh produce can readily lead to pathogen cross-contamination with pre-sliced tomatoes having been linked to multistate outbreaks of salmonellosis in the United States. This study aimed to assess the impact of multiple processing variables on quantitative transfer of Salmonella during simulated commercial slicing of tomatoes. One red round tomato was inoculated with Salmonella Typhimurium LT2 at ~5logCFU/g and sliced using a manual or electric slicer, followed by 20 uninoculated tomatoes. Thereafter, the distribution of Salmonella on inoculated and uninoculated tomato slices was evaluated along with the transfer of Salmonella from different parts of the slicer. The impact of multiple processing variables including post-contamination hold time (0 and 30min), tomato wetness (dry and wet), processing room temperature (23, 10 and 4°C), slice thickness (0.48, 0.64, and 0.95cm), tomato variety (Torero, Rebelski, and Bigdena) and pre-wash treatment (no wash, tap water, and chlorine) was also investigated. The data were fitted to a two-parameter exponential decay model (Y=A⋅exp(BX)) with the percentage of Salmonella transferred to 20 uninoculated tomatoes then calculated. Salmonella populations on nine inoculated tomato slices ranged from 4.6±0.2 to 5.5±0.3logCFU/g, with higher populations on slices from the blossom and stem scar ends. However, Salmonella transfer to the previously uninoculated slices was similar (P>0.05), ranging from 2.1±0.2 to 3.4±0.2logCFU/g. Significantly fewer salmonellae transferred from the blade (3.4±0.4 log CFU, P≤0.05) than from the back and bottom plates (4.7±0.3 log CFU) or the whole manual slicer (5.2±0.2 log CFU) to the 20 uninoculated tomatoes. However, the blade was the primary contributor to Salmonella transfer for the electric slicer. Post-contamination hold time, processing temperature and tomato slice thickness did not significantly impact (P>0.05) the Salmonella transfer rate (parameter B) or the overall

  11. FORTRAN code-evaluation system

    NASA Technical Reports Server (NTRS)

    Capps, J. D.; Kleir, R.

    1977-01-01

    Automated code evaluation system can be used to detect coding errors and unsound coding practices in any ANSI FORTRAN IV source code before they can cause execution-time malfunctions. System concentrates on acceptable FORTRAN code features which are likely to produce undesirable results.

  12. FAST2 Code validation

    SciTech Connect

    Wilson, R.E.; Freeman, L.N.; Walker, S.N.

    1995-09-01

    The FAST2 Code which is capable of determining structural loads of a flexible, teetering, horizontal axis wind turbine is described and comparisons of calculated loads with test data at two wind speeds for the ESI-80 are given. The FAST2 Code models a two-bladed HAWT with degrees of freedom for blade flap, teeter, drive train flexibility, yaw, and windwise and crosswind tower motion. The code allows blade dimensions, stiffness, and weights to differ and models tower shadow, wind shear, and turbulence. Additionally, dynamic stall is included as are delta-3 and an underslung rotor. Load comparisons are made with ESI-80 test data in the form of power spectral density, rainflow counting, occurrence histograms and azimuth averaged bin plots. It is concluded that agreement between the FAST2 Code and test results is good.

  13. Compressible Astrophysics Simulation Code

    Energy Science and Technology Software Center (ESTSC)

    2007-07-18

    This is an astrophysics simulation code involving a radiation diffusion module developed at LLNL coupled to compressible hydrodynamics and adaptive mesh infrastructure developed at LBNL. One intended application is to neutrino diffusion in core collapse supernovae.

  14. Comparison of the Microflex LT and Vitek MS Systems for Routine Identification of Bacteria by Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry

    PubMed Central

    Busson, Laurent; Wybo, Ingrid; El Haj, Rachid Ait; Dediste, Anne; Vandenberg, Olivier

    2012-01-01

    This study compared the performance of three matrix-assisted laser desorption ionization–time of flight mass spectrometry systems: Microflex LT (Bruker Daltonics, Bremen, Germany), Vitek MS RUO (Axima Assurance-Saramis database; bioMérieux, Marcy l'Etoile, France), and Vitek MS IVD (bioMérieux). A total of 1,129 isolates, including 1,003 routine isolates, 73 anaerobes, and 53 bacterial enteropathogens, were tested on the Microflex LT and Axima Assurance devices. The spectra were analyzed using three databases: Biotyper (Bruker Daltonics), Saramis, and Vitek MS (bioMérieux). Among the routine isolates requiring identification to the species level (n = 986), 92.7% and 93.2% were correctly identified by the Biotyper and Vitek MS databases, respectively. The Vitek MS database is more specific for the identification of Streptococcus viridans. For the anaerobes, the Biotyper database often identified Fusobacterium isolates to only the genus level, which is of low clinical significance, whereas 20% of the Bacteroides species were not identified or were misidentified by the Vitek MS database. For the enteropathogens, the poor discrimination between Escherichia coli and Shigella explains the high proportion of unidentified organisms. In contrast to the Biotyper database, the Vitek MS database properly discriminated all of the Salmonella entrica serovar Typhi isolates (n = 5). The performance of the Saramis database was globally poorer. In conclusion, for routine procedures, the Microflex LT and Vitek-MS systems are equally good choices in terms of analytical efficiency. Other factors, including price, work flow, and lab activity, will affect the choice of a system. PMID:22322345

  15. Seals Flow Code Development

    NASA Technical Reports Server (NTRS)

    1991-01-01

    In recognition of a deficiency in the current modeling capability for seals, an effort was established by NASA to develop verified computational fluid dynamic concepts, codes, and analyses for seals. The objectives were to develop advanced concepts for the design and analysis of seals, to effectively disseminate the information to potential users by way of annual workshops, and to provide experimental verification for the models and codes under a wide range of operating conditions.

  16. Structure–activity correlations of variant forms of the B pentamer of Escherichia coli type II heat-labile enterotoxin LT-IIb with Toll-like receptor 2 binding

    SciTech Connect

    Cody, Vivian; Pace, Jim; Nawar, Hesham F.; King-Lyons, Natalie; Liang, Shuang; Connell, Terry D.; Hajishengallis, George

    2012-12-01

    Structural data for the S74D variant of the pentameric B subunit of type II heat-labile enterotoxin of Escherichia coli reveal a smaller pore opening that may explain its reduced Toll-like receptor binding affinity compared to that of the wild type enterotoxin. The explanation for the enhanced Toll-like receptor binding affinity of the S74A variant is more complex than simply being attributed to the pore opening. The pentameric B subunit of the type II heat-labile enterotoxin of Escherichia coli (LT-IIb-B{sub 5}) is a potent signaling molecule capable of modulating innate immune responses. It has previously been shown that LT-IIb-B{sub 5}, but not the LT-IIb-B{sub 5} Ser74Asp variant [LT-IIb-B{sub 5}(S74D)], activates Toll-like receptor (TLR2) signaling in macrophages. Consistent with this, the LT-IIb-B{sub 5}(S74D) variant failed to bind TLR2, in contrast to LT-IIb-B{sub 5} and the LT-IIb-B{sub 5} Thr13Ile [LT-IIb-B{sub 5}(T13I)] and LT-IIb-B{sub 5} Ser74Ala [LT-IIb-B{sub 5}(S74A)] variants, which displayed the highest binding activity to TLR2. Crystal structures of the Ser74Asp, Ser74Ala and Thr13Ile variants of LT-IIb-B{sub 5} have been determined to 1.90, 1.40 and 1.90 Å resolution, respectively. The structural data for the Ser74Asp variant reveal that the carboxylate side chain points into the pore, thereby reducing the pore size compared with that of the wild-type or the Ser74Ala variant B pentamer. On the basis of these crystallographic data, the reduced TLR2-binding affinity of the LT-IIb-B{sub 5}(S74D) variant may be the result of the pore of the pentamer being closed. On the other hand, the explanation for the enhanced TLR2-binding activity of the LT-IIb-B{sub 5}(S74A) variant is more complex as its activity is greater than that of the wild-type B pentamer, which also has an open pore as the Ser74 side chain points away from the pore opening. Data for the LT-IIb-B{sub 5}(T13I) variant show that four of the five variant side chains point to the outside

  17. Robust Nonlinear Neural Codes

    NASA Astrophysics Data System (ADS)

    Yang, Qianli; Pitkow, Xaq

    2015-03-01

    Most interesting natural sensory stimuli are encoded in the brain in a form that can only be decoded nonlinearly. But despite being a core function of the brain, nonlinear population codes are rarely studied and poorly understood. Interestingly, the few existing models of nonlinear codes are inconsistent with known architectural features of the brain. In particular, these codes have information content that scales with the size of the cortical population, even if that violates the data processing inequality by exceeding the amount of information entering the sensory system. Here we provide a valid theory of nonlinear population codes by generalizing recent work on information-limiting correlations in linear population codes. Although these generalized, nonlinear information-limiting correlations bound the performance of any decoder, they also make decoding more robust to suboptimal computation, allowing many suboptimal decoders to achieve nearly the same efficiency as an optimal decoder. Although these correlations are extremely difficult to measure directly, particularly for nonlinear codes, we provide a simple, practical test by which one can use choice-related activity in small populations of neurons to determine whether decoding is suboptimal or optimal and limited by correlated noise. We conclude by describing an example computation in the vestibular system where this theory applies. QY and XP was supported by a grant from the McNair foundation.

  18. Pharmacological differences among CysLT(1) receptor antagonists with respect to LTC(4) and LTD(4) in human lung parenchyma.

    PubMed

    Ravasi, Saula; Capra, Valérie; Panigalli, Tiziana; Rovati, G Enrico; Nicosia, Simonetta

    2002-04-15

    We have previously reported, by means of equilibrium binding studies, the existence of two distinct binding sites with receptor characteristics for LTC(4) and LTD(4) in human lung parenchyma (HLP) membranes using S-decyl-glutathione (S-decyl-GSH) to inhibit LTC(4) binding to a number of non-receptor sites. Recently, we have been able to avoid the use of S-decyl-GSH in kinetic experiments and to characterize a distinctive pharmacological profile for the LTC(4) high affinity binding sites which do not correlates with the ability of both LTD(4) and LTC(4) to contract isolated HLP strips through the CysLT(1) receptor. Here, we report that the most advanced CysLT(1) receptor antagonists, some of which are already in clinical use, displayed a different behavior toward LTC(4) and LTD(4) in HLP. Equilibrium and kinetic binding studies demonstrated the following rank order of potency for (3)H-LTD(4) receptor (CysLT(1)): zafirlukast = montelukast > LM-1507 = LM-1484 = pranlukast. In addition, LM-1507, LM-1484, pranlukast and montelukast but not zafirlukast are able to interact also with the high affinity site for (3)H-LTC(4) (LM-1507 = LM-1484 > pranlukast; montelukast not detectable in the presence of S-decyl-GSH). In this respect, the behavior of the LM antagonists closely resembles that of pranlukast although LM-1507 and LM-1484 display a higher affinity for (3)H-LTC(4) sites. Montelukast has an intermediate behavior, inasmuch as its interaction with (3)H-LTC(4) sites can be revealed only in kinetic studies, while zafirlukast is totally unable to inhibit (3)H-LTC(4) binding. It might be, therefore, most relevant for a complete understanding of the clinical efficacy, besides their nominal potency, of the most advanced CysLT(1) receptor antagonists to consider their pharmacological differences with respect not only to LTD(4)/LTE(4), but also to LTC(4). PMID:11996896

  19. Multi-phase Nature of a Radiation-driven Fountain with Nuclear Starburst in a Low-mass Active Galactic Nucleus

    NASA Astrophysics Data System (ADS)

    Wada, Keiichi; Schartmann, Marc; Meijerink, Rowin

    2016-09-01

    The structures and dynamics of molecular, atomic, and ionized gases are studied around a low-luminosity active galactic nucleus (AGN) with a small (2× {10}6{M}ȯ ) black hole using three-dimensional (3D) radiation–hydrodynamic simulations. We studied, for the first time, the non-equilibrium chemistry for the X-ray-dominated region in the “radiation-driven fountain” with supernova feedback. A double hollow cone structure is naturally formed without postulating a thick “torus” around a central source. The cone is occupied with an inhomogeneous, diffuse ionized gas and surrounded by a geometrically thick (h/r≳ 1) atomic gas. Dense molecular gases are distributed near the equatorial plane, and energy feedback from supernovae enhances their scale height. Molecular hydrogen exists in a hot phase (>1000 K) as well as in a cold (\\lt 100 {{K}}), dense (\\gt {10}3 {{cm}}-3) phase. The velocity dispersion of H2 in the vertical direction is comparable to the rotational velocity, which is consistent with near-infrared observations of nearby Seyfert galaxies. Using 3D radiation transfer calculations for the dust emission, we find polar emission in the mid-infrared band (12 μm), which is associated with bipolar outflows, as suggested in recent interferometric observations of nearby AGNs. If the viewing angle for the nucleus is larger than 75°, the spectral energy distribution is consistent with that of the Circinus galaxy. The multi-phase interstellar medium observed in optical/infrared and X-ray observations is also discussed.

  20. Coded source neutron imaging

    SciTech Connect

    Bingham, Philip R; Santos-Villalobos, Hector J

    2011-01-01

    Coded aperture techniques have been applied to neutron radiography to address limitations in neutron flux and resolution of neutron detectors in a system labeled coded source imaging (CSI). By coding the neutron source, a magnified imaging system is designed with small spot size aperture holes (10 and 100 m) for improved resolution beyond the detector limits and with many holes in the aperture (50% open) to account for flux losses due to the small pinhole size. An introduction to neutron radiography and coded aperture imaging is presented. A system design is developed for a CSI system with a development of equations for limitations on the system based on the coded image requirements and the neutron source characteristics of size and divergence. Simulation has been applied to the design using McStas to provide qualitative measures of performance with simulations of pinhole array objects followed by a quantitative measure through simulation of a tilted edge and calculation of the modulation transfer function (MTF) from the line spread function. MTF results for both 100um and 10um aperture hole diameters show resolutions matching the hole diameters.

  1. Error coding simulations

    NASA Technical Reports Server (NTRS)

    Noble, Viveca K.

    1993-01-01

    There are various elements such as radio frequency interference (RFI) which may induce errors in data being transmitted via a satellite communication link. When a transmission is affected by interference or other error-causing elements, the transmitted data becomes indecipherable. It becomes necessary to implement techniques to recover from these disturbances. The objective of this research is to develop software which simulates error control circuits and evaluate the performance of these modules in various bit error rate environments. The results of the evaluation provide the engineer with information which helps determine the optimal error control scheme. The Consultative Committee for Space Data Systems (CCSDS) recommends the use of Reed-Solomon (RS) and convolutional encoders and Viterbi and RS decoders for error correction. The use of forward error correction techniques greatly reduces the received signal to noise needed for a certain desired bit error rate. The use of concatenated coding, e.g. inner convolutional code and outer RS code, provides even greater coding gain. The 16-bit cyclic redundancy check (CRC) code is recommended by CCSDS for error detection.

  2. Error coding simulations

    NASA Astrophysics Data System (ADS)

    Noble, Viveca K.

    1993-11-01

    There are various elements such as radio frequency interference (RFI) which may induce errors in data being transmitted via a satellite communication link. When a transmission is affected by interference or other error-causing elements, the transmitted data becomes indecipherable. It becomes necessary to implement techniques to recover from these disturbances. The objective of this research is to develop software which simulates error control circuits and evaluate the performance of these modules in various bit error rate environments. The results of the evaluation provide the engineer with information which helps determine the optimal error control scheme. The Consultative Committee for Space Data Systems (CCSDS) recommends the use of Reed-Solomon (RS) and convolutional encoders and Viterbi and RS decoders for error correction. The use of forward error correction techniques greatly reduces the received signal to noise needed for a certain desired bit error rate. The use of concatenated coding, e.g. inner convolutional code and outer RS code, provides even greater coding gain. The 16-bit cyclic redundancy check (CRC) code is recommended by CCSDS for error detection.

  3. Polygenic inheritance of sensorineural hearing loss (Snhl2, -3, and -4) and organ of Corti patterning defect in the ALR/LtJ mouse strain.

    PubMed

    Latoche, Joseph R; Neely, Harold R; Noben-Trauth, Konrad

    2011-05-01

    Progressive sensorineural hearing loss in humans is a common and debilitating impairment. Sensorineural deafness in inbred strains of mice is a similarly common and genetically diverse phenotype providing experimental models to study the underlying genetics and the biological effects of the risk factors. Here, we report that ALR/LtJ mice develop early-onset profound sensorineural hearing loss as evidenced by high-to-low frequency hearing threshold shifts, absent distortion-product otoacoustic emissions, and normal endocochlear potentials. Linkage analyses of a segregating backcross revealed three novel quantitative trait loci named sensorineural hearing loss (Snhl) -2, -3, and -4. The QTLs achieved very high LOD scores with markers on chromosome 1 (Snhl2, LOD: 12), chromosome 6 (Snhl3, LOD: 24) and chromosome 10 (Snhl4, LOD: 11). Together, they explained 90% of the phenotypic variance. While Snhl2 and Snhl3 affected hearing thresholds across a broad range of test frequencies, Snhl4 caused primarily high-frequency hearing loss. The hearing impairment is accompanied by an organ of Corti patterning defect that is characterized by the ectopic expression of supernumerary outer hair cells organized in rows along the abneural site of the sensory epithelium in the presence of unaltered planar polarity and otherwise normal cochlear duct morphology. Cloning the Snhl2, -3, and -4 genes in the ALR/LtJ mice may provide important genetic and mechanistic insights into the pathology of human progressive sensorineural deafness. PMID:21185929

  4. Performances and Reliability of Bruker Microflex LT and VITEK MS MALDI-TOF Mass Spectrometry Systems for the Identification of Clinical Microorganisms

    PubMed Central

    Yaman, Gorkem; Ciftci, Ugur; Laleli, Yahya Rauf

    2015-01-01

    In clinical microbiology laboratories, routine microbial identification is mostly performed using culture based methodologies requiring 24 to 72 hours from culturing to identification. Matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) technology has been established as a cost effective, reliable, and faster alternative identification platform. In this study, we evaluated the reliability of the two available MALDI-TOF MS systems for their routine clinical level identification accuracy and efficiency in a clinical microbiology laboratory setting. A total of 1,341 routine phenotypically identified clinical bacterial and fungal isolates were selected and simultaneously analyzed using VITEK MS (bioMérieux, France) and Microflex LT (Bruker Diagnostics, Germany) MALDI-TOF MS systems. For any isolate that could not be identified with either of the systems and for any discordant result, 16S rDNA gene or ITS1/ITS2 sequencing was used. VITEK MS and Microflex LT correctly identified 1,303 (97.17%) and 1,298 (96.79%) isolates to the species level, respectively. In 114 (8.50%) isolates initial phenotypic identification was inaccurate. Both systems showed a similar identification efficiency and workflow robustness, and they were twice as more accurate compared to routine phenotypic identification in our sample pool. MALDITOF systems with their accuracy and robustness offer a good identification platform for routine clinical microbiology laboratories. PMID:26793718

  5. Preventing adhesion of Escherichia coli O157:H7 and Salmonella Typhimurium LT2 on tomato surfaces via ultrathin polyethylene glycol film.

    PubMed

    Zhang, Ming; Yang, Fan; Pasupuleti, Sasikiran; Oh, Jun Kyun; Kohli, Nandita; Lee, I-Syuan; Perez, Keila; Verkhoturov, Stanislav V; Schweikert, Emile A; Jayaraman, Arul; Cisneros-Zevallos, Luis; Akbulut, Mustafa

    2014-08-18

    This work deals with adhesion of Escherichia coli O157:H7 and Salmonella enterica subsp. enterica serovar Typhimurium LT2 (S. Typhimurium LT2) on polyethylene glycol (PEG) coated tomato surfaces. PEG coating was characterized by water contact angle technique, scanning electron microscopy, and secondary ion mass spectrometry. It was shown that PEG films could physisorb on the tomato surfaces after the oxygen plasma treatment, which made some outermost layers of the surfaces hydrophilic. Bacterial adhesion on PEG coated tomato surface was studied by standard plate count, fluorescence microscopy, and scanning electron microscopy techniques. Fully covered PEG film reduced the bacterial attachment 90% or more in comparison to the bare tomato surface. The degree of bacterial attachment decreased exponentially with increasing PEG coverage. When desired, PEG film could be removed by rinsing with water. Overall, this work demonstrates the proof-of-concept that an ultrathin film of polyethylene glycol may be used to effectively inhibit the attachment of pathogenic bacteria on tomato surfaces. PMID:24935688

  6. Evaluation of Metal Halide, Plasma, and LED Lighting Technologies for a Hydrogen Fuel Cell Mobile Light (H 2 LT)

    SciTech Connect

    Miller, L. B.; Donohoe, S. P.; Jones, M. H.; White, W. A.; Klebanoff, L. E.; Velinsky, S. A.

    2015-04-22

    This article reports on the testing and comparison of a prototype hydrogen fuel cell light tower (H2LT) and a conventional diesel-powered metal halide light trailer for use in road maintenance and construction activities. The prototype was originally outfitted with plasma lights and then with light-emitting diode (LED) luminaires. Light output and distribution, lighting energy efficiency (i.e., efficacy), power source thermal efficiency, and fuel costs are compared. The metal halide luminaires have 2.2 and 3.1 times more light output than the plasma and LED luminaires, respectively, but they require more power/lumen to provide that output. The LED luminaires have 1.6 times better light efficacy than either the metal halide or plasma luminaires. The light uniformity ratios produced by the plasma and LED towers are acceptable. The fuel cell thermal efficiency at the power required to operate the plasma lights is 48%, significantly higher than the diesel generator efficiency of 23% when operating the metal halide lights. Due to the increased efficiency of the fuel cell and the LED lighting, the fuel cost per lumen-hour of the H2LT is 62% of the metal halide diesel light tower assuming a kilogram of hydrogen is twice the cost of a gallon of diesel fuel.

  7. Long non-coding RNA MALAT-1 overexpression predicts tumor recurrence of hepatocellular carcinoma after liver transplantation.

    PubMed

    Lai, Ming-chun; Yang, Zhe; Zhou, Lin; Zhu, Qian-qian; Xie, Hai-yang; Zhang, Feng; Wu, Li-ming; Chen, Lei-ming; Zheng, Shu-sen

    2012-09-01

    Metastasis-associated lung adenocarcinoma transcript 1(MALAT1), a long non-coding RNA (lncRNA), is up-regulated in many solid tumors and associated with cancer metastasis and recurrence. However, its role in hepatocellular carcinoma (HCC) remains poorly understood. In the present study, we evaluated the expression of MALAT1 by quantitative real-time PCR in 9 liver cancer cell lines and 112 HCC cases including 60 cases who received liver transplantation (LT) with complete follow-up data. Moreover, small interfering RNA (siRNA) was used to inhibit MALAT1 expression to investigate its biological role in tumor progression. We found that MALAT1 was up-regulated in both cell lines and clinical tissue samples. Patients with high expression level of MALAT1 had a significantly increased risk of tumor recurrence after LT, particularly in patients who exceeded the Milan criteria. On multivariate analysis, MALAT1 was an independent prognostic factor for predicting HCC recurrence (hazard ratio, 3.280, P = 0.003).In addition, inhibition of MALAT1 in HepG2 cells could effectively reduce cell viability, motility, invasiveness, and increase the sensitivity to apoptosis. Our data suggest that lncRNA MALAT1 play an important role in tumor progression and could be a novel biomarker for predicting tumor recurrence after LT and serve as a promising therapeutic target. PMID:21678027

  8. Phase-coded pulse aperiodic transmitter coding

    NASA Astrophysics Data System (ADS)

    Virtanen, I. I.; Vierinen, J.; Lehtinen, M. S.

    2009-07-01

    Both ionospheric and weather radar communities have already adopted the method of transmitting radar pulses in an aperiodic manner when measuring moderately overspread targets. Among the users of the ionospheric radars, this method is called Aperiodic Transmitter Coding (ATC), whereas the weather radar users have adopted the term Simultaneous Multiple Pulse-Repetition Frequency (SMPRF). When probing the ionosphere at the carrier frequencies of the EISCAT Incoherent Scatter Radar facilities, the range extent of the detectable target is typically of the order of one thousand kilometers - about seven milliseconds - whereas the characteristic correlation time of the scattered signal varies from a few milliseconds in the D-region to only tens of microseconds in the F-region. If one is interested in estimating the scattering autocorrelation function (ACF) at time lags shorter than the F-region correlation time, the D-region must be considered as a moderately overspread target, whereas the F-region is a severely overspread one. Given the technical restrictions of the radar hardware, a combination of ATC and phase-coded long pulses is advantageous for this kind of target. We evaluate such an experiment under infinitely low signal-to-noise ratio (SNR) conditions using lag profile inversion. In addition, a qualitative evaluation under high-SNR conditions is performed by analysing simulated data. The results show that an acceptable estimation accuracy and a very good lag resolution in the D-region can be achieved with a pulse length long enough for simultaneous E- and F-region measurements with a reasonable lag extent. The new experiment design is tested with the EISCAT Tromsø VHF (224 MHz) radar. An example of a full D/E/F-region ACF from the test run is shown at the end of the paper.

  9. Lithium isotopes in Guatemalan and Franciscan HP-LT rocks: Insights into the role of sediment-derived fluids during subduction

    NASA Astrophysics Data System (ADS)

    Simons, Kyla K.; Harlow, George E.; Brueckner, Hannes K.; Goldstein, Steven L.; Sorensen, Sorena S.; Hemming, N. Gary; Langmuir, Charles H.

    2010-06-01

    High-pressure, low-temperature (HP-LT) rocks from a Cretaceous age subduction complex occur as tectonic blocks in serpentinite mélange along the Motagua Fault (MF) in central Guatemala. Eclogite and jadeitite among these are characterized by trace element patterns with enrichments in fluid mobile elements, similar to arc lavas. Eclogite is recrystallized from MORB-like altered oceanic crust, presumably at the boundary between the down-going plate and overlying mantle wedge. Eclogite geochemistry, mineralogy and petrography suggest a two step petrogenesis of (1) dehydration during prograde metamorphism at low temperatures (<500 °C) followed by (2) partial rehydration/fertilization at even lower T during exhumation. In contrast, Guatemalan jadeitites are crystallized directly from low- T aqueous fluid as veins in serpentinizing mantle during both subduction and exhumation. The overall chemistry and mineralogy of Guatemalan eclogites are similar to those from the Franciscan Complex, California, implying similar P- T- x paths. Li concentrations (⩽90 ppm) in mineral separates and whole rocks (WR) from Guatemalan and Franciscan HP-LT rocks are significantly higher than MORB (4-6 ppm), but similar to HP-LT rocks globally. Li isotopic compositions range from -5‰ to +5‰ for Guatemalan HP-LT rocks, and -4‰ to +1‰ for Franciscan eclogites, overlapping previous findings for other HP-LT suites. The combination of Li concentrations greater than MORB, and Li isotopic values lighter than MORB are inconsistent with a simple dehydration model. We prefer a model in which Li systematics in Guatemalan and Franciscan eclogites reflect reequilibration with subduction fluids during exhumation. Roughly 5-10% of the Li in these fluids is derived from sediments. Model results predict that the dehydrated bulk ocean crust is isotopically lighter (δ 7Li ⩽ +1 ± 3‰) than the depleted mantle (˜+3.5 ± 0.5‰), while the mantle wedge beneath the arc is the isotopic complement of

  10. Geometry of Pacific plate in Kuril-Japan trench zones estimated from earthquake distribution using LT-OBS network and seismic structures by marine surveys

    NASA Astrophysics Data System (ADS)

    Shinohara, M.; Yamada, T.; Kuwano, A.; Nakahigashi, K.; Machida, Y.; Mochizuki, K.; Kanazawa, T.; Takanami, T.; Hino, R.

    2009-12-01

    The seismicity of the Japan arc region is as high as that observed in other areas of subduction of oceanic plates. The Japan Trench and Kuril Trench are plate convergent zones where the Pacific Plate is subducting below the Japan island. In addition, the trench is crooked off Erimo cape, Hokkaido. It is considered the bend of the trench causes complex shape of the plate boundary. There is a possibility that an asperity of a large earthquake is controlled by a shape of a plate boundary. Associated with the plate convergence, many earthquakes occur beneath landward slopes of the Japan Trench and the Kuril Trench. Such earthquakes are considered to occur mainly at plate boundary between the Pacific plate and the landward plate in landward slope of the Kuril trench and the Japan trench. Therefore, to obtain precise hypocenter distribution of earthquakes occurring in the regions is essential to estimate geometry of the plate boundary. For several years, we performed dense seafloor earthquake observation using Long-Term Ocean Bottom Seismometers (LT-OBSs) in this region, including the aftershock observation of the 2003 Tokachi-oki earthquakes which is a large interplate earthquake around the Japan island arc. In the region off Nemuro, dense seafloor observation was carried out from 2005 to 2006 for one year using LT-OBSs. In the region off Aomori, we performed the same type of a seafloor earthquake observation from 2004 to 2007 for two years in total. Ninety-two LT-OBSs were used for the observations, and an interval of the LT-OBS is approximately 20 km. The LT-OBS has three-component seismometer with a natural period of 1 Hz, and reaches a recoding period of 1 year. As a result, we obtained the precise hypocenter distribution from the region off Nemuro to the region off Aomori, and the hypocenter distribution of huge number of earthquakes enables us to estimate the geometry of the plate boundary. Additionally, seismic surveys using OBSs and controlled source were

  11. FAA Smoke Transport Code

    Energy Science and Technology Software Center (ESTSC)

    2006-10-27

    FAA Smoke Transport Code, a physics-based Computational Fluid Dynamics tool, which couples heat, mass, and momentum transfer, has been developed to provide information on smoke transport in cargo compartments with various geometries and flight conditions. The software package contains a graphical user interface for specification of geometry and boundary conditions, analysis module for solving the governing equations, and a post-processing tool. The current code was produced by making substantial improvements and additions to a codemore » obtained from a university. The original code was able to compute steady, uniform, isothermal turbulent pressurization. In addition, a preprocessor and postprocessor were added to arrive at the current software package.« less

  12. Seals Code Development Workshop

    NASA Technical Reports Server (NTRS)

    Hendricks, Robert C. (Compiler); Liang, Anita D. (Compiler)

    1996-01-01

    Seals Workshop of 1995 industrial code (INDSEAL) release include ICYL, GCYLT, IFACE, GFACE, SPIRALG, SPIRALI, DYSEAL, and KTK. The scientific code (SCISEAL) release includes conjugate heat transfer and multidomain with rotordynamic capability. Several seals and bearings codes (e.g., HYDROFLEX, HYDROTRAN, HYDROB3D, FLOWCON1, FLOWCON2) are presented and results compared. Current computational and experimental emphasis includes multiple connected cavity flows with goals of reducing parasitic losses and gas ingestion. Labyrinth seals continue to play a significant role in sealing with face, honeycomb, and new sealing concepts under investigation for advanced engine concepts in view of strict environmental constraints. The clean sheet approach to engine design is advocated with program directions and anticipated percentage SFC reductions cited. Future activities center on engine applications with coupled seal/power/secondary flow streams.

  13. Code query by example

    NASA Astrophysics Data System (ADS)

    Vaucouleur, Sebastien

    2011-02-01

    We introduce code query by example for customisation of evolvable software products in general and of enterprise resource planning systems (ERPs) in particular. The concept is based on an initial empirical study on practices around ERP systems. We motivate our design choices based on those empirical results, and we show how the proposed solution helps with respect to the infamous upgrade problem: the conflict between the need for customisation and the need for upgrade of ERP systems. We further show how code query by example can be used as a form of lightweight static analysis, to detect automatically potential defects in large software products. Code query by example as a form of lightweight static analysis is particularly interesting in the context of ERP systems: it is often the case that programmers working in this field are not computer science specialists but more of domain experts. Hence, they require a simple language to express custom rules.

  14. Code inspection instructional validation

    NASA Technical Reports Server (NTRS)

    Orr, Kay; Stancil, Shirley

    1992-01-01

    The Shuttle Data Systems Branch (SDSB) of the Flight Data Systems Division (FDSD) at Johnson Space Center contracted with Southwest Research Institute (SwRI) to validate the effectiveness of an interactive video course on the code inspection process. The purpose of this project was to determine if this course could be effective for teaching NASA analysts the process of code inspection. In addition, NASA was interested in the effectiveness of this unique type of instruction (Digital Video Interactive), for providing training on software processes. This study found the Carnegie Mellon course, 'A Cure for the Common Code', effective for teaching the process of code inspection. In addition, analysts prefer learning with this method of instruction, or this method in combination with other methods. As is, the course is definitely better than no course at all; however, findings indicate changes are needed. Following are conclusions of this study. (1) The course is instructionally effective. (2) The simulation has a positive effect on student's confidence in his ability to apply new knowledge. (3) Analysts like the course and prefer this method of training, or this method in combination with current methods of training in code inspection, over the way training is currently being conducted. (4) Analysts responded favorably to information presented through scenarios incorporating full motion video. (5) Some course content needs to be changed. (6) Some content needs to be added to the course. SwRI believes this study indicates interactive video instruction combined with simulation is effective for teaching software processes. Based on the conclusions of this study, SwRI has outlined seven options for NASA to consider. SwRI recommends the option which involves creation of new source code and data files, but uses much of the existing content and design from the current course. Although this option involves a significant software development effort, SwRI believes this option

  15. Aeroacoustic Prediction Codes

    NASA Technical Reports Server (NTRS)

    Gliebe, P; Mani, R.; Shin, H.; Mitchell, B.; Ashford, G.; Salamah, S.; Connell, S.; Huff, Dennis (Technical Monitor)

    2000-01-01

    This report describes work performed on Contract NAS3-27720AoI 13 as part of the NASA Advanced Subsonic Transport (AST) Noise Reduction Technology effort. Computer codes were developed to provide quantitative prediction, design, and analysis capability for several aircraft engine noise sources. The objective was to provide improved, physics-based tools for exploration of noise-reduction concepts and understanding of experimental results. Methods and codes focused on fan broadband and 'buzz saw' noise and on low-emissions combustor noise and compliment work done by other contractors under the NASA AST program to develop methods and codes for fan harmonic tone noise and jet noise. The methods and codes developed and reported herein employ a wide range of approaches, from the strictly empirical to the completely computational, with some being semiempirical analytical, and/or analytical/computational. Emphasis was on capturing the essential physics while still considering method or code utility as a practical design and analysis tool for everyday engineering use. Codes and prediction models were developed for: (1) an improved empirical correlation model for fan rotor exit flow mean and turbulence properties, for use in predicting broadband noise generated by rotor exit flow turbulence interaction with downstream stator vanes: (2) fan broadband noise models for rotor and stator/turbulence interaction sources including 3D effects, noncompact-source effects. directivity modeling, and extensions to the rotor supersonic tip-speed regime; (3) fan multiple-pure-tone in-duct sound pressure prediction methodology based on computational fluid dynamics (CFD) analysis; and (4) low-emissions combustor prediction methodology and computer code based on CFD and actuator disk theory. In addition. the relative importance of dipole and quadrupole source mechanisms was studied using direct CFD source computation for a simple cascadeigust interaction problem, and an empirical combustor

  16. Securing mobile code.

    SciTech Connect

    Link, Hamilton E.; Schroeppel, Richard Crabtree; Neumann, William Douglas; Campbell, Philip LaRoche; Beaver, Cheryl Lynn; Pierson, Lyndon George; Anderson, William Erik

    2004-10-01

    If software is designed so that the software can issue functions that will move that software from one computing platform to another, then the software is said to be 'mobile'. There are two general areas of security problems associated with mobile code. The 'secure host' problem involves protecting the host from malicious mobile code. The 'secure mobile code' problem, on the other hand, involves protecting the code from malicious hosts. This report focuses on the latter problem. We have found three distinct camps of opinions regarding how to secure mobile code. There are those who believe special distributed hardware is necessary, those who believe special distributed software is necessary, and those who believe neither is necessary. We examine all three camps, with a focus on the third. In the distributed software camp we examine some commonly proposed techniques including Java, D'Agents and Flask. For the specialized hardware camp, we propose a cryptographic technique for 'tamper-proofing' code over a large portion of the software/hardware life cycle by careful modification of current architectures. This method culminates by decrypting/authenticating each instruction within a physically protected CPU, thereby protecting against subversion by malicious code. Our main focus is on the camp that believes that neither specialized software nor hardware is necessary. We concentrate on methods of code obfuscation to render an entire program or a data segment on which a program depends incomprehensible. The hope is to prevent or at least slow down reverse engineering efforts and to prevent goal-oriented attacks on the software and execution. The field of obfuscation is still in a state of development with the central problem being the lack of a basis for evaluating the protection schemes. We give a brief introduction to some of the main ideas in the field, followed by an in depth analysis of a technique called 'white-boxing'. We put forth some new attacks and improvements

  17. Accumulate Repeat Accumulate Coded Modulation

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative coded modulation scheme called 'Accumulate Repeat Accumulate Coded Modulation' (ARA coded modulation). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes that are combined with high level modulation. Thus at the decoder belief propagation can be used for iterative decoding of ARA coded modulation on a graph, provided a demapper transforms the received in-phase and quadrature samples to reliability of the bits.

  18. Multiple trellis coded modulation

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    A technique for designing trellis codes to minimize bit error performance for a fading channel. The invention provides a criteria which may be used in the design of such codes which is significantly different from that used for average white Gaussian noise channels. The method of multiple trellis coded modulation of the present invention comprises the steps of: (a) coding b bits of input data into s intermediate outputs; (b) grouping said s intermediate outputs into k groups of s.sub.i intermediate outputs each where the summation of all s.sub.i,s is equal to s and k is equal to at least 2; (c) mapping each of said k groups of intermediate outputs into one of a plurality of symbols in accordance with a plurality of modulation schemes, one for each group such that the first group is mapped in accordance with a first modulation scheme and the second group is mapped in accordance with a second modulation scheme; and (d) outputting each of said symbols to provide k output symbols for each b bits of input data.

  19. Code of Ethics.

    ERIC Educational Resources Information Center

    American Sociological Association, Washington, DC.

    The American Sociological Association's code of ethics for sociologists is presented. For sociological research and practice, 10 requirements for ethical behavior are identified, including: maintaining objectivity and integrity; fully reporting findings and research methods, without omission of significant data; reporting fully all sources of…

  20. Sharing the Code.

    ERIC Educational Resources Information Center

    Olsen, Florence

    2003-01-01

    Colleges and universities are beginning to consider collaborating on open-source-code projects as a way to meet critical software and computing needs. Points out the attractive features of noncommercial open-source software and describes some examples in use now, especially for the creation of Web infrastructure. (SLD)

  1. Electrical Circuit Simulation Code

    Energy Science and Technology Software Center (ESTSC)

    2001-08-09

    Massively-Parallel Electrical Circuit Simulation Code. CHILESPICE is a massively-arallel distributed-memory electrical circuit simulation tool that contains many enhanced radiation, time-based, and thermal features and models. Large scale electronic circuit simulation. Shared memory, parallel processing, enhance convergence. Sandia specific device models.

  2. The Redox Code

    PubMed Central

    Jones, Dean P.

    2015-01-01

    Abstract Significance: The redox code is a set of principles that defines the positioning of the nicotinamide adenine dinucleotide (NAD, NADP) and thiol/disulfide and other redox systems as well as the thiol redox proteome in space and time in biological systems. The code is richly elaborated in an oxygen-dependent life, where activation/deactivation cycles involving O2 and H2O2 contribute to spatiotemporal organization for differentiation, development, and adaptation to the environment. Disruption of this organizational structure during oxidative stress represents a fundamental mechanism in system failure and disease. Recent Advances: Methodology in assessing components of the redox code under physiological conditions has progressed, permitting insight into spatiotemporal organization and allowing for identification of redox partners in redox proteomics and redox metabolomics. Critical Issues: Complexity of redox networks and redox regulation is being revealed step by step, yet much still needs to be learned. Future Directions: Detailed knowledge of the molecular patterns generated from the principles of the redox code under defined physiological or pathological conditions in cells and organs will contribute to understanding the redox component in health and disease. Ultimately, there will be a scientific basis to a modern redox medicine. Antioxid. Redox Signal. 23, 734–746. PMID:25891126

  3. Environmental Fluid Dynamics Code

    EPA Science Inventory

    The Environmental Fluid Dynamics Code (EFDC)is a state-of-the-art hydrodynamic model that can be used to simulate aquatic systems in one, two, and three dimensions. It has evolved over the past two decades to become one of the most widely used and technically defensible hydrodyn...

  4. Heuristic dynamic complexity coding

    NASA Astrophysics Data System (ADS)

    Škorupa, Jozef; Slowack, Jürgen; Mys, Stefaan; Lambert, Peter; Van de Walle, Rik

    2008-04-01

    Distributed video coding is a new video coding paradigm that shifts the computational intensive motion estimation from encoder to decoder. This results in a lightweight encoder and a complex decoder, as opposed to the predictive video coding scheme (e.g., MPEG-X and H.26X) with a complex encoder and a lightweight decoder. Both schemas, however, do not have the ability to adapt to varying complexity constraints imposed by encoder and decoder, which is an essential ability for applications targeting a wide range of devices with different complexity constraints or applications with temporary variable complexity constraints. Moreover, the effect of complexity adaptation on the overall compression performance is of great importance and has not yet been investigated. To address this need, we have developed a video coding system with the possibility to adapt itself to complexity constraints by dynamically sharing the motion estimation computations between both components. On this system we have studied the effect of the complexity distribution on the compression performance. This paper describes how motion estimation can be shared using heuristic dynamic complexity and how distribution of complexity affects the overall compression performance of the system. The results show that the complexity can indeed be shared between encoder and decoder in an efficient way at acceptable rate-distortion performance.

  5. Code of Ethics.

    ERIC Educational Resources Information Center

    Association of College Unions-International, Bloomington, IN.

    The code of ethics for the college union and student activities professional is presented by the Association of College Unions-International. The preamble identifies the objectives of the college union as providing campus community centers and social programs that enhance the quality of life for members of the academic community. Ethics for…

  6. Dual Coding in Children.

    ERIC Educational Resources Information Center

    Burton, John K.; Wildman, Terry M.

    The purpose of this study was to test the applicability of the dual coding hypothesis to children's recall performance. The hypothesis predicts that visual interference will have a small effect on the recall of visually presented words or pictures, but that acoustic interference will cause a decline in recall of visually presented words and…

  7. The revised genetic code

    NASA Astrophysics Data System (ADS)

    Ninio, Jacques

    1990-03-01

    Recent findings on the genetic code are reviewed, including selenocysteine usage, deviations in the assignments of sense and nonsense codons, RNA editing, natural ribosomal frameshifts and non-orthodox codon-anticodon pairings. A multi-stage codon reading process is presented.

  8. Dress Codes and Uniforms.

    ERIC Educational Resources Information Center

    Lumsden, Linda; Miller, Gabriel

    2002-01-01

    Students do not always make choices that adults agree with in their choice of school dress. Dress-code issues are explored in this Research Roundup, and guidance is offered to principals seeking to maintain a positive school climate. In "Do School Uniforms Fit?" Kerry White discusses arguments for and against school uniforms and summarizes the…

  9. Code Optimization Techniques

    SciTech Connect

    MAGEE,GLEN I.

    2000-08-03

    Computers transfer data in a number of different ways. Whether through a serial port, a parallel port, over a modem, over an ethernet cable, or internally from a hard disk to memory, some data will be lost. To compensate for that loss, numerous error detection and correction algorithms have been developed. One of the most common error correction codes is the Reed-Solomon code, which is a special subset of BCH (Bose-Chaudhuri-Hocquenghem) linear cyclic block codes. In the AURA project, an unmanned aircraft sends the data it collects back to earth so it can be analyzed during flight and possible flight modifications made. To counter possible data corruption during transmission, the data is encoded using a multi-block Reed-Solomon implementation with a possibly shortened final block. In order to maximize the amount of data transmitted, it was necessary to reduce the computation time of a Reed-Solomon encoding to three percent of the processor's time. To achieve such a reduction, many code optimization techniques were employed. This paper outlines the steps taken to reduce the processing time of a Reed-Solomon encoding and the insight into modern optimization techniques gained from the experience.

  10. Binary coding for hyperspectral imagery

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Chang, Chein-I.; Chang, Chein-Chi; Lin, Chinsu

    2004-10-01

    Binary coding is one of simplest ways to characterize spectral features. One commonly used method is a binary coding-based image software system, called Spectral Analysis Manager (SPAM) for remotely sensed imagery developed by Mazer et al. For a given spectral signature, the SPAM calculates its spectral mean and inter-band spectral difference and uses them as thresholds to generate a binary code word for this particular spectral signature. Such coding scheme is generally effective and also very simple to implement. This paper revisits the SPAM and further develops three new SPAM-based binary coding methods, called equal probability partition (EPP) binary coding, halfway partition (HP) binary coding and median partition (MP) binary coding. These three binary coding methods along with the SPAM well be evaluated for spectral discrimination and identification. In doing so, a new criterion, called a posteriori discrimination probability (APDP) is also introduced for performance measure.

  11. Fluorescence-based thermal shift data on multidrug regulator AcrR from Salmonella enterica subsp. entrica serovar Typhimurium str. LT2.

    PubMed

    Manjasetty, Babu A; Halavaty, Andrei S; Luan, Chi-Hao; Osipiuk, Jerzy; Mulligan, Rory; Kwon, Keehwan; Anderson, Wayne F; Joachimiak, Andrzej

    2016-06-01

    The fluorescence-based thermal shift (FTS) data presented here include Table S1 and Fig. S1, and are supplemental to our original research article describing detailed structural, FTS, and fluorescence polarization analyses of the Salmonella enterica subsp. entrica serovar Typhimurium str. LT2 multidrug transcriptional regulator AcrR (StAcrR) (doi:10.1016/j.jsb.2016.01.008) (Manjasetty et al., 2015 [1]). Table S1 contains chemical formulas, a Chemical Abstracts Service (CAS) Registry Number (CAS no.), FTS rank (a ligand with the highest rank) has the largest difference in the melting temperature (ΔT m), and uses as drug molecules against various pathological conditions of sixteen small-molecule ligands that increase thermal stability of StAcrR. Thermal stability of human enolase 1, a negative control protein, was not affected in the presence of various concentrations of the top six StAcrR binders (Fig. S1). PMID:27054155

  12. The adjuvants MF59 and LT-K63 enhance the mucosal and systemic immunogenicity of subunit influenza vaccine administered intranasally in mice.

    PubMed

    Barchfeld, G L; Hessler, A L; Chen, M; Pizza, M; Rappuoli, R; Van Nest, G A

    1999-02-26

    Commercial influenza vaccines generate serum antibody, but not local IgA. Influenza vaccines that induce both serum and secretory antibody are more likely to protect against infection and disease progression. The adjuvants MF59 and LT-K63 were tested intramuscularly and intranasally with subunit HA. In naive mice, intranasal adjuvant effect was more apparent when included with the first than second immunization. In previously infected mice, intranasal adjuvants had little effect on serum antibodies and were most effective for nasal antibodies after the second immunization. Overall, both adjuvants enhanced anti-HA IgA and IgG by intranasal vaccination whereas, by intramuscular vaccination, they only enhanced serum IgG. PMID:10067675

  13. Sinusoidal transform coding

    NASA Technical Reports Server (NTRS)

    Mcaulay, Robert J.; Quatieri, Thomas F.

    1988-01-01

    It has been shown that an analysis/synthesis system based on a sinusoidal representation of speech leads to synthetic speech that is essentially perceptually indistinguishable from the original. Strategies for coding the amplitudes, frequencies and phases of the sine waves have been developed that have led to a multirate coder operating at rates from 2400 to 9600 bps. The encoded speech is highly intelligible at all rates with a uniformly improving quality as the data rate is increased. A real-time fixed-point implementation has been developed using two ADSP2100 DSP chips. The methods used for coding and quantizing the sine-wave parameters for operation at the various frame rates are described.

  14. Finite Element Analysis Code

    Energy Science and Technology Software Center (ESTSC)

    2006-03-08

    MAPVAR-KD is designed to transfer solution results from one finite element mesh to another. MAPVAR-KD draws heavily from the structure and coding of MERLIN II, but it employs a new finite element data base, EXODUS II, and offers enhanced speed and new capabilities not available in MERLIN II. In keeping with the MERLIN II documentation, the computational algorithms used in MAPVAR-KD are described. User instructions are presented. Example problems are included to demonstrate the operationmore » of the code and the effects of various input options. MAPVAR-KD is a modification of MAPVAR in which the search algorithm was replaced by a kd-tree-based search for better performance on large problems.« less

  15. Confocal coded aperture imaging

    DOEpatents

    Tobin, Jr., Kenneth William; Thomas, Jr., Clarence E.

    2001-01-01

    A method for imaging a target volume comprises the steps of: radiating a small bandwidth of energy toward the target volume; focusing the small bandwidth of energy into a beam; moving the target volume through a plurality of positions within the focused beam; collecting a beam of energy scattered from the target volume with a non-diffractive confocal coded aperture; generating a shadow image of said aperture from every point source of radiation in the target volume; and, reconstructing the shadow image into a 3-dimensional image of the every point source by mathematically correlating the shadow image with a digital or analog version of the coded aperture. The method can comprise the step of collecting the beam of energy scattered from the target volume with a Fresnel zone plate.

  16. CTI Correction Code

    NASA Astrophysics Data System (ADS)

    Massey, Richard; Stoughton, Chris; Leauthaud, Alexie; Rhodes, Jason; Koekemoer, Anton; Ellis, Richard; Shaghoulian, Edgar

    2013-07-01

    Charge Transfer Inefficiency (CTI) due to radiation damage above the Earth's atmosphere creates spurious trailing in images from Charge-Coupled Device (CCD) imaging detectors. Radiation damage also creates unrelated warm pixels, which can be used to measure CTI. This code provides pixel-based correction for CTI and has proven effective in Hubble Space Telescope Advanced Camera for Surveys raw images, successfully reducing the CTI trails by a factor of ~30 everywhere in the CCD and at all flux levels. The core is written in java for speed, and a front-end user interface is provided in IDL. The code operates on raw data by returning individual electrons to pixels from which they were unintentionally dragged during readout. Correction takes about 25 minutes per ACS exposure, but is trivially parallelisable to multiple processors.

  17. LARGE-AMPLITUDE VARIATIONS OF AN L/T TRANSITION BROWN DWARF: MULTI-WAVELENGTH OBSERVATIONS OF PATCHY, HIGH-CONTRAST CLOUD FEATURES

    SciTech Connect

    Radigan, Jacqueline; Jayawardhana, Ray; Lafreniere, David; Artigau, Etienne; Marley, Mark; Saumon, Didier

    2012-05-10

    We present multiple-epoch photometric monitoring in the J, H, and K{sub s} bands of the T1.5 dwarf 2MASS J21392676+0220226 (2M2139), revealing persistent, periodic (P = 7.721 {+-} 0.005 hr) variability with a peak-to-peak amplitude as high as 26% in the J band. The light curve shape varies on a timescale of days, suggesting that evolving atmospheric cloud features are responsible. Using interpolations between model atmospheres with differing cloud thicknesses to represent a heterogeneous surface, we find that the multi-wavelength variations and the near-infrared spectrum of 2M2139 can be reproduced by either (1) cool, thick cloud features sitting above a thinner cloud layer, or (2) warm regions of low condensate opacity in an otherwise cloudy atmosphere, possibly indicating the presence of holes or breaks in the cloud layer. We find that temperature contrasts between thick and thin cloud patches must be greater than 175 K and as high as 425 K. We also consider whether the observed variability could arise from an interacting binary system, but this scenario is ruled out. 2M2139 joins the T2.5 dwarf SIMP0136 discovered by Artigau and coworkers as the second L/T transition brown dwarf to display large-amplitude variability on rotational timescales, suggesting that the fragmentation of dust clouds at the L/T transition may contribute to the abrupt decline in condensate opacity and J-band brightening observed to occur over this regime.

  18. Status of MARS Code

    SciTech Connect

    N.V. Mokhov

    2003-04-09

    Status and recent developments of the MARS 14 Monte Carlo code system for simulation of hadronic and electromagnetic cascades in shielding, accelerator and detector components in the energy range from a fraction of an electronvolt up to 100 TeV are described. these include physics models both in strong and electromagnetic interaction sectors, variance reduction techniques, residual dose, geometry, tracking, histograming. MAD-MARS Beam Line Build and Graphical-User Interface.

  19. VAC: Versatile Advection Code

    NASA Astrophysics Data System (ADS)

    Tóth, Gábor; Keppens, Rony

    2012-07-01

    The Versatile Advection Code (VAC) is a freely available general hydrodynamic and magnetohydrodynamic simulation software that works in 1, 2 or 3 dimensions on Cartesian and logically Cartesian grids. VAC runs on any Unix/Linux system with a Fortran 90 (or 77) compiler and Perl interpreter. VAC can run on parallel machines using either the Message Passing Interface (MPI) library or a High Performance Fortran (HPF) compiler.

  20. Reeds computer code

    NASA Technical Reports Server (NTRS)

    Bjork, C.

    1981-01-01

    The REEDS (rocket exhaust effluent diffusion single layer) computer code is used for the estimation of certain rocket exhaust effluent concentrations and dosages and their distributions near the Earth's surface following a rocket launch event. Output from REEDS is used in producing near real time air quality and environmental assessments of the effects of certain potentially harmful effluents, namely HCl, Al2O3, CO, and NO.

  1. Cholera toxin, and the related nontoxic adjuvants mmCT and dmLT, promote human Th17 responses via cyclic AMP-protein kinase A and inflammasome-dependent IL-1 signaling.

    PubMed

    Larena, Maximilian; Holmgren, Jan; Lebens, Michael; Terrinoni, Manuela; Lundgren, Anna

    2015-04-15

    We have examined the molecular pathways involved in the adjuvant action of cholera toxin (CT) and two novel nontoxic molecules, multiple-mutated CT (mmCT) and double-mutant heat-labile toxin (dmLT) on human T cell responses. Human PBMCs or isolated monocytes were stimulated in vitro with CT, mmCT, or dmLT plus a polyclonal stimulus (staphylococcal enterotoxin B) or specific bacterial Ags, and effects on expression of cytokines and signaling molecules were determined. CT, mmCT, and dmLT strongly enhanced IL-17A and to a lesser extent IL-13 responses, but had little effect on IFN-γ production or cell proliferation. Intracellular cytokine staining revealed that the enhanced IL-17A production was largely confined to CD4(+) T cells and coculture experiments showed that the IL-17A promotion was effectively induced by adjuvant-treated monocytes. Relative to CT, mmCT and dmLT induced at least 100-fold lower levels of cAMP, yet this cAMP was enough and essential for the promotion of Th17 responses. Thus, inhibition of cAMP-dependent protein kinase A was abolished, and stimulation with a cAMP analog mimicked the adjuvant effect. Furthermore, CT, mmCT, and dmLT induced IL-1β production and caspase-1 activation in monocytes, which was associated with increased expression of key proinflammatory and inflammasome-related genes, including NLRP1, NLRP3, and NLRC4. Inflammasome inhibition with a specific caspase-1 inhibitor, or blocking of IL-1 signaling by IL-1 receptor antagonist, abrogated the Th17-promoting effect. We conclude that CT, mmCT, and dmLT promote human Th17 responses via cAMP-dependent protein kinase A and caspase-1/inflammasome-dependent IL-1 signaling. PMID:25786687

  2. MELCOR computer code manuals

    SciTech Connect

    Summers, R.M.; Cole, R.K. Jr.; Smith, R.C.; Stuart, D.S.; Thompson, S.L.; Hodge, S.A.; Hyman, C.R.; Sanders, R.L.

    1995-03-01

    MELCOR is a fully integrated, engineering-level computer code that models the progression of severe accidents in light water reactor nuclear power plants. MELCOR is being developed at Sandia National Laboratories for the U.S. Nuclear Regulatory Commission as a second-generation plant risk assessment tool and the successor to the Source Term Code Package. A broad spectrum of severe accident phenomena in both boiling and pressurized water reactors is treated in MELCOR in a unified framework. These include: thermal-hydraulic response in the reactor coolant system, reactor cavity, containment, and confinement buildings; core heatup, degradation, and relocation; core-concrete attack; hydrogen production, transport, and combustion; fission product release and transport; and the impact of engineered safety features on thermal-hydraulic and radionuclide behavior. Current uses of MELCOR include estimation of severe accident source terms and their sensitivities and uncertainties in a variety of applications. This publication of the MELCOR computer code manuals corresponds to MELCOR 1.8.3, released to users in August, 1994. Volume 1 contains a primer that describes MELCOR`s phenomenological scope, organization (by package), and documentation. The remainder of Volume 1 contains the MELCOR Users Guides, which provide the input instructions and guidelines for each package. Volume 2 contains the MELCOR Reference Manuals, which describe the phenomenological models that have been implemented in each package.

  3. Bar coded retroreflective target

    DOEpatents

    Vann, Charles S.

    2000-01-01

    This small, inexpensive, non-contact laser sensor can detect the location of a retroreflective target in a relatively large volume and up to six degrees of position. The tracker's laser beam is formed into a plane of light which is swept across the space of interest. When the beam illuminates the retroreflector, some of the light returns to the tracker. The intensity, angle, and time of the return beam is measured to calculate the three dimensional location of the target. With three retroreflectors on the target, the locations of three points on the target are measured, enabling the calculation of all six degrees of target position. Until now, devices for three-dimensional tracking of objects in a large volume have been heavy, large, and very expensive. Because of the simplicity and unique characteristics of this tracker, it is capable of three-dimensional tracking of one to several objects in a large volume, yet it is compact, light-weight, and relatively inexpensive. Alternatively, a tracker produces a diverging laser beam which is directed towards a fixed position, and senses when a retroreflective target enters the fixed field of view. An optically bar coded target can be read by the tracker to provide information about the target. The target can be formed of a ball lens with a bar code on one end. As the target moves through the field, the ball lens causes the laser beam to scan across the bar code.

  4. Suboptimum decoding of block codes

    NASA Technical Reports Server (NTRS)

    Lin, Shu; Kasami, Tadao

    1991-01-01

    This paper investigates a class of decomposable codes, their distance and structural properties. it is shown that this class includes several classes of well known and efficient codes as subclasses. Several methods for constructing decomposable codes or decomposing codes are presented. A two-stage soft decision decoding scheme for decomposable codes, their translates or unions of translates is devised. This two-stage soft-decision decoding is suboptimum, and provides an excellent trade-off between the error performance and decoding complexity for codes of moderate and long block length.

  5. Preliminary Assessment of Turbomachinery Codes

    NASA Technical Reports Server (NTRS)

    Mazumder, Quamrul H.

    2007-01-01

    This report assesses different CFD codes developed and currently being used at Glenn Research Center to predict turbomachinery fluid flow and heat transfer behavior. This report will consider the following codes: APNASA, TURBO, GlennHT, H3D, and SWIFT. Each code will be described separately in the following section with their current modeling capabilities, level of validation, pre/post processing, and future development and validation requirements. This report addresses only previously published and validations of the codes. However, the codes have been further developed to extend the capabilities of the codes.

  6. Structural coding versus free-energy predictive coding.

    PubMed

    van der Helm, Peter A

    2016-06-01

    Focusing on visual perceptual organization, this article contrasts the free-energy (FE) version of predictive coding (a recent Bayesian approach) to structural coding (a long-standing representational approach). Both use free-energy minimization as metaphor for processing in the brain, but their formal elaborations of this metaphor are fundamentally different. FE predictive coding formalizes it by minimization of prediction errors, whereas structural coding formalizes it by minimization of the descriptive complexity of predictions. Here, both sides are evaluated. A conclusion regarding competence is that FE predictive coding uses a powerful modeling technique, but that structural coding has more explanatory power. A conclusion regarding performance is that FE predictive coding-though more detailed in its account of neurophysiological data-provides a less compelling cognitive architecture than that of structural coding, which, for instance, supplies formal support for the computationally powerful role it attributes to neuronal synchronization. PMID:26407895

  7. Convolutional coding techniques for data protection

    NASA Technical Reports Server (NTRS)

    Massey, J. L.

    1975-01-01

    Results of research on the use of convolutional codes in data communications are presented. Convolutional coding fundamentals are discussed along with modulation and coding interaction. Concatenated coding systems and data compression with convolutional codes are described.

  8. Combinatorial neural codes from a mathematical coding theory perspective.

    PubMed

    Curto, Carina; Itskov, Vladimir; Morrison, Katherine; Roth, Zachary; Walker, Judy L

    2013-07-01

    Shannon's seminal 1948 work gave rise to two distinct areas of research: information theory and mathematical coding theory. While information theory has had a strong influence on theoretical neuroscience, ideas from mathematical coding theory have received considerably less attention. Here we take a new look at combinatorial neural codes from a mathematical coding theory perspective, examining the error correction capabilities of familiar receptive field codes (RF codes). We find, perhaps surprisingly, that the high levels of redundancy present in these codes do not support accurate error correction, although the error-correcting performance of receptive field codes catches up to that of random comparison codes when a small tolerance to error is introduced. However, receptive field codes are good at reflecting distances between represented stimuli, while the random comparison codes are not. We suggest that a compromise in error-correcting capability may be a necessary price to pay for a neural code whose structure serves not only error correction, but must also reflect relationships between stimuli. PMID:23724797

  9. On lossless coding for HEVC

    NASA Astrophysics Data System (ADS)

    Gao, Wen; Jiang, Minqiang; Yu, Haoping

    2013-02-01

    In this paper, we first review the lossless coding mode in the version 1 of the HEVC standard that has recently finalized. We then provide a performance comparison between the lossless coding mode in the HEVC and MPEG-AVC/H.264 standards and show that the HEVC lossless coding has limited coding efficiency. To improve the performance of the lossless coding mode, several new coding tools that were contributed to JCT-VC but not adopted in version 1 of HEVC standard are introduced. In particular, we discuss sample based intra prediction and coding of residual coefficients in more detail. At the end, we briefly address a new class of coding tools, i.e., a dictionary-based coder, that is efficient in encoding screen content including graphics and text.

  10. Noiseless Coding Of Magnetometer Signals

    NASA Technical Reports Server (NTRS)

    Rice, Robert F.; Lee, Jun-Ji

    1989-01-01

    Report discusses application of noiseless data-compression coding to digitized readings of spaceborne magnetometers for transmission back to Earth. Objective of such coding to increase efficiency by decreasing rate of transmission without sacrificing integrity of data. Adaptive coding compresses data by factors ranging from 2 to 6.

  11. Energy Codes and Standards: Facilities

    SciTech Connect

    Bartlett, Rosemarie; Halverson, Mark A.; Shankle, Diana L.

    2007-01-01

    Energy codes and standards play a vital role in the marketplace by setting minimum requirements for energy-efficient design and construction. They outline uniform requirements for new buildings as well as additions and renovations. This article covers basic knowledge of codes and standards; development processes of each; adoption, implementation, and enforcement of energy codes and standards; and voluntary energy efficiency programs.

  12. Coding Issues in Grounded Theory

    ERIC Educational Resources Information Center

    Moghaddam, Alireza

    2006-01-01

    This paper discusses grounded theory as one of the qualitative research designs. It describes how grounded theory generates from data. Three phases of grounded theory--open coding, axial coding, and selective coding--are discussed, along with some of the issues which are the source of debate among grounded theorists, especially between its…

  13. Authorship Attribution of Source Code

    ERIC Educational Resources Information Center

    Tennyson, Matthew F.

    2013-01-01

    Authorship attribution of source code is the task of deciding who wrote a program, given its source code. Applications include software forensics, plagiarism detection, and determining software ownership. A number of methods for the authorship attribution of source code have been presented in the past. A review of those existing methods is…

  14. Ethical Codes in the Professions.

    ERIC Educational Resources Information Center

    Schmeiser, Cynthia B.

    1992-01-01

    Whether the measurement profession should consider developing and adopting a code of professional conduct is explored after a brief review of existing references to standards of conduct and a review of other professional codes. Issues include the need for a code of ethics, its usefulness, and its enforcement. (SLD)

  15. Finite Element Analysis Code

    Energy Science and Technology Software Center (ESTSC)

    2005-05-07

    CONEX is a code for joining sequentially in time multiple exodusll database files which all represent the same base mesh topology and geometry. It is used to create a single results or restart file from multiple results or restart files which typically arise as the result of multiple restarted analyses. CONEX is used to postprocess the results from a series of finite element analyses. It can join sequentially the data from multiple results databases intomore » a single database which makes it easier to postprocess the results data.« less

  16. Finite Element Analysis Code

    Energy Science and Technology Software Center (ESTSC)

    2005-06-26

    Exotxt is an analysis code that reads finite element results data stored in an exodusII file and generates a file in a structured text format. The text file can be edited or modified via a number of text formatting tools. Exotxt is used by analysis to translate data from the binary exodusII format into a structured text format which can then be edited or modified and then either translated back to exodusII format or tomore » another format.« less

  17. Low Density Parity Check Codes: Bandwidth Efficient Channel Coding

    NASA Technical Reports Server (NTRS)

    Fong, Wai; Lin, Shu; Maki, Gary; Yeh, Pen-Shu

    2003-01-01

    Low Density Parity Check (LDPC) Codes provide near-Shannon Capacity performance for NASA Missions. These codes have high coding rates R=0.82 and 0.875 with moderate code lengths, n=4096 and 8176. Their decoders have inherently parallel structures which allows for high-speed implementation. Two codes based on Euclidean Geometry (EG) were selected for flight ASIC implementation. These codes are cyclic and quasi-cyclic in nature and therefore have a simple encoder structure. This results in power and size benefits. These codes also have a large minimum distance as much as d,,, = 65 giving them powerful error correcting capabilities and error floors less than lo- BER. This paper will present development of the LDPC flight encoder and decoder, its applications and status.

  18. New quantum codes constructed from quaternary BCH codes

    NASA Astrophysics Data System (ADS)

    Xu, Gen; Li, Ruihu; Guo, Luobin; Ma, Yuena

    2016-07-01

    In this paper, we firstly study construction of new quantum error-correcting codes (QECCs) from three classes of quaternary imprimitive BCH codes. As a result, the improved maximal designed distance of these narrow-sense imprimitive Hermitian dual-containing quaternary BCH codes are determined to be much larger than the result given according to Aly et al. (IEEE Trans Inf Theory 53:1183-1188, 2007) for each different code length. Thus, families of new QECCs are newly obtained, and the constructed QECCs have larger distance than those in the previous literature. Secondly, we apply a combinatorial construction to the imprimitive BCH codes with their corresponding primitive counterpart and construct many new linear quantum codes with good parameters, some of which have parameters exceeding the finite Gilbert-Varshamov bound for linear quantum codes.

  19. Structured error recovery for code-word-stabilized quantum codes

    SciTech Connect

    Li Yunfan; Dumer, Ilya; Grassl, Markus; Pryadko, Leonid P.

    2010-05-15

    Code-word-stabilized (CWS) codes are, in general, nonadditive quantum codes that can correct errors by an exhaustive search of different error patterns, similar to the way that we decode classical nonlinear codes. For an n-qubit quantum code correcting errors on up to t qubits, this brute-force approach consecutively tests different errors of weight t or less and employs a separate n-qubit measurement in each test. In this article, we suggest an error grouping technique that allows one to simultaneously test large groups of errors in a single measurement. This structured error recovery technique exponentially reduces the number of measurements by about 3{sup t} times. While it still leaves exponentially many measurements for a generic CWS code, the technique is equivalent to syndrome-based recovery for the special case of additive CWS codes.

  20. Measuring Diagnoses: ICD Code Accuracy

    PubMed Central

    O'Malley, Kimberly J; Cook, Karon F; Price, Matt D; Wildes, Kimberly Raiford; Hurdle, John F; Ashton, Carol M

    2005-01-01

    Objective To examine potential sources of errors at each step of the described inpatient International Classification of Diseases (ICD) coding process. Data Sources/Study Setting The use of disease codes from the ICD has expanded from classifying morbidity and mortality information for statistical purposes to diverse sets of applications in research, health care policy, and health care finance. By describing a brief history of ICD coding, detailing the process for assigning codes, identifying where errors can be introduced into the process, and reviewing methods for examining code accuracy, we help code users more systematically evaluate code accuracy for their particular applications. Study Design/Methods We summarize the inpatient ICD diagnostic coding process from patient admission to diagnostic code assignment. We examine potential sources of errors at each step and offer code users a tool for systematically evaluating code accuracy. Principle Findings Main error sources along the “patient trajectory” include amount and quality of information at admission, communication among patients and providers, the clinician's knowledge and experience with the illness, and the clinician's attention to detail. Main error sources along the “paper trail” include variance in the electronic and written records, coder training and experience, facility quality-control efforts, and unintentional and intentional coder errors, such as misspecification, unbundling, and upcoding. Conclusions By clearly specifying the code assignment process and heightening their awareness of potential error sources, code users can better evaluate the applicability and limitations of codes for their particular situations. ICD codes can then be used in the most appropriate ways. PMID:16178999

  1. Genetic code for sine

    NASA Astrophysics Data System (ADS)

    Abdullah, Alyasa Gan; Wah, Yap Bee

    2015-02-01

    The computation of the approximate values of the trigonometric sines was discovered by Bhaskara I (c. 600-c.680), a seventh century Indian mathematician and is known as the Bjaskara's I's sine approximation formula. The formula is given in his treatise titled Mahabhaskariya. In the 14th century, Madhava of Sangamagrama, a Kerala mathematician astronomer constructed the table of trigonometric sines of various angles. Madhava's table gives the measure of angles in arcminutes, arcseconds and sixtieths of an arcsecond. The search for more accurate formulas led to the discovery of the power series expansion by Madhava of Sangamagrama (c.1350-c. 1425), the founder of the Kerala school of astronomy and mathematics. In 1715, the Taylor series was introduced by Brook Taylor an English mathematician. If the Taylor series is centered at zero, it is called a Maclaurin series, named after the Scottish mathematician Colin Maclaurin. Some of the important Maclaurin series expansions include trigonometric functions. This paper introduces the genetic code of the sine of an angle without using power series expansion. The genetic code using square root approach reveals the pattern in the signs (plus, minus) and sequence of numbers in the sine of an angle. The square root approach complements the Pythagoras method, provides a better understanding of calculating an angle and will be useful for teaching the concepts of angles in trigonometry.

  2. Determinate-state convolutional codes

    NASA Technical Reports Server (NTRS)

    Collins, O.; Hizlan, M.

    1991-01-01

    A determinate state convolutional code is formed from a conventional convolutional code by pruning away some of the possible state transitions in the decoding trellis. The type of staged power transfer used in determinate state convolutional codes proves to be an extremely efficient way of enhancing the performance of a concatenated coding system. The decoder complexity is analyzed along with free distances of these new codes and extensive simulation results is provided of their performance at the low signal to noise ratios where a real communication system would operate. Concise, practical examples are provided.

  3. Coding for reliable satellite communications

    NASA Technical Reports Server (NTRS)

    Gaarder, N. T.; Lin, S.

    1986-01-01

    This research project was set up to study various kinds of coding techniques for error control in satellite and space communications for NASA Goddard Space Flight Center. During the project period, researchers investigated the following areas: (1) decoding of Reed-Solomon codes in terms of dual basis; (2) concatenated and cascaded error control coding schemes for satellite and space communications; (3) use of hybrid coding schemes (error correction and detection incorporated with retransmission) to improve system reliability and throughput in satellite communications; (4) good codes for simultaneous error correction and error detection, and (5) error control techniques for ring and star networks.

  4. Circular codes, symmetries and transformations.

    PubMed

    Fimmel, Elena; Giannerini, Simone; Gonzalez, Diego Luis; Strüngmann, Lutz

    2015-06-01

    Circular codes, putative remnants of primeval comma-free codes, have gained considerable attention in the last years. In fact they represent a second kind of genetic code potentially involved in detecting and maintaining the normal reading frame in protein coding sequences. The discovering of an universal code across species suggested many theoretical and experimental questions. However, there is a key aspect that relates circular codes to symmetries and transformations that remains to a large extent unexplored. In this article we aim at addressing the issue by studying the symmetries and transformations that connect different circular codes. The main result is that the class of 216 C3 maximal self-complementary codes can be partitioned into 27 equivalence classes defined by a particular set of transformations. We show that such transformations can be put in a group theoretic framework with an intuitive geometric interpretation. More general mathematical results about symmetry transformations which are valid for any kind of circular codes are also presented. Our results pave the way to the study of the biological consequences of the mathematical structure behind circular codes and contribute to shed light on the evolutionary steps that led to the observed symmetries of present codes. PMID:25008961

  5. dc-free coset codes

    NASA Technical Reports Server (NTRS)

    Deng, Robert H.; Herro, Mark A.

    1988-01-01

    A class of block coset codes with disparity and run-length constraints are studied. They are particularly well suited for high-speed optical fiber links and similar channels, where dc-free pulse formats, channel error control, and low-complexity encoder-decoder implementations are required. The codes are derived by partitioning linear block codes. The encoder and decoder structures are the same as those of linear block codes with only slight modifications. A special class of dc-free coset block codes are derived from BCH codes with specified bounds on minimum distance, disparity, and run length. The codes have low disparity levels (a small running digital sum) and good error-correcting capabilities.

  6. Permutation-invariant quantum codes

    NASA Astrophysics Data System (ADS)

    Ouyang, Yingkai

    2014-12-01

    A quantum code is a subspace of a Hilbert space of a physical system chosen to be correctable against a given class of errors, where information can be encoded. Ideally, the quantum code lies within the ground space of the physical system. When the physical model is the Heisenberg ferromagnet in the absence of an external magnetic field, the corresponding ground space contains all permutation-invariant states. We use techniques from combinatorics and operator theory to construct families of permutation-invariant quantum codes. These codes have length proportional to t2; one family of codes perfectly corrects arbitrary weight t errors, while the other family of codes approximately correct t spontaneous decay errors. The analysis of our codes' performance with respect to spontaneous decay errors utilizes elementary matrix analysis, where we revisit and extend the quantum error correction criterion of Knill and Laflamme, and Leung, Chuang, Nielsen and Yamamoto.

  7. Making your code citable with the Astrophysics Source Code Library

    NASA Astrophysics Data System (ADS)

    Allen, Alice; DuPrie, Kimberly; Schmidt, Judy; Berriman, G. Bruce; Hanisch, Robert J.; Mink, Jessica D.; Nemiroff, Robert J.; Shamir, Lior; Shortridge, Keith; Taylor, Mark B.; Teuben, Peter J.; Wallin, John F.

    2016-01-01

    The Astrophysics Source Code Library (ASCL, ascl.net) is a free online registry of codes used in astronomy research. With nearly 1,200 codes, it is the largest indexed resource for astronomy codes in existence. Established in 1999, it offers software authors a path to citation of their research codes even without publication of a paper describing the software, and offers scientists a way to find codes used in refereed publications, thus improving the transparency of the research. It also provides a method to quantify the impact of source codes in a fashion similar to the science metrics of journal articles. Citations using ASCL IDs are accepted by major astronomy journals and if formatted properly are tracked by ADS and other indexing services. The number of citations to ASCL entries increased sharply from 110 citations in January 2014 to 456 citations in September 2015. The percentage of code entries in ASCL that were cited at least once rose from 7.5% in January 2014 to 17.4% in September 2015. The ASCL's mid-2014 infrastructure upgrade added an easy entry submission form, more flexible browsing, search capabilities, and an RSS feeder for updates. A Changes/Additions form added this past fall lets authors submit links for papers that use their codes for addition to the ASCL entry even if those papers don't formally cite the codes, thus increasing the transparency of that research and capturing the value of their software to the community.

  8. Practices in Code Discoverability: Astrophysics Source Code Library

    NASA Astrophysics Data System (ADS)

    Allen, A.; Teuben, P.; Nemiroff, R. J.; Shamir, L.

    2012-09-01

    Here we describe the Astrophysics Source Code Library (ASCL), which takes an active approach to sharing astrophysics source code. ASCL's editor seeks out both new and old peer-reviewed papers that describe methods or experiments that involve the development or use of source code, and adds entries for the found codes to the library. This approach ensures that source codes are added without requiring authors to actively submit them, resulting in a comprehensive listing that covers a significant number of the astrophysics source codes used in peer-reviewed studies. The ASCL now has over 340 codes in it and continues to grow. In 2011, the ASCL has on average added 19 codes per month. An advisory committee has been established to provide input and guide the development and expansion of the new site, and a marketing plan has been developed and is being executed. All ASCL source codes have been used to generate results published in or submitted to a refereed journal and are freely available either via a download site or from an identified source. This paper provides the history and description of the ASCL. It lists the requirements for including codes, examines the advantages of the ASCL, and outlines some of its future plans.

  9. Bacillus sp. LT3 improves the survival of gnotobiotic brine shrimp (Artemia franciscana) larvae challenged with Vibrio campbellii by enhancing the innate immune response and by decreasing the activity of shrimp-associated vibrios.

    PubMed

    Niu, Yufeng; Defoirdt, Tom; Baruah, Kartik; Van de Wiele, Tom; Dong, Shuanglin; Bossier, Peter

    2014-10-10

    Bacteria belonging to the genus Bacillus are amongst the most intensively studied group of bacteria for use as probiotics in aquaculture. However, the exact mechanism of action of these bacteria is often not well described, and the microbiota that are naturally present in cultures of test organisms often compromise the interpretation of the results. The present study aimed to evaluate the putative probiotic effect of Bacillus sp. LT3 in a model system with gnotobiotic brine shrimp Artemia franciscana larvae. The strain significantly increased the survival of brine shrimp larvae challenged with Vibrio campbellii when administered 6h before the challenge. Under these conditions, LT3 was able to colonize the brine shrimp gastrointestinal tract and to decrease the in vivo pathogen activity as indicated by the bioluminescence of the V. campbellii associated with brine shrimp larvae. In order to investigate the effect of the Bacillus strain on the innate immune system of the brine shrimp larvae, prophenoloxidase and transglutaminase mRNA levels were monitored, while heat shock protein 70 mRNA levels were measured as an indicator of physiological stress. Interestingly, 12h after challenge, the prophenoloxidase mRNA level in the larvae pre-treated with LT3 and challenged with V. campbellii was approximately 8-fold higher than in the other treatments. Further, a decreased mRNA level of transglutaminase gene and heat shock protein 70 gene suggested that pretreatment with LT3 results in less stress and tissue damage in the brine shrimp larvae upon V. campbellii challenge. These results indicated that Bacillus sp. LT3 could improve the survival of brine shrimp larvae when challenged with pathogenic V. campbellii, both by decreasing the in vivo activity of the pathogen and by priming the innate immune response through activating the prophenoloxidase system. PMID:25190276

  10. Surface acoustic wave coding for orthogonal frequency coded devices

    NASA Technical Reports Server (NTRS)

    Malocha, Donald (Inventor); Kozlovski, Nikolai (Inventor)

    2011-01-01

    Methods and systems for coding SAW OFC devices to mitigate code collisions in a wireless multi-tag system. Each device producing plural stepped frequencies as an OFC signal with a chip offset delay to increase code diversity. A method for assigning a different OCF to each device includes using a matrix based on the number of OFCs needed and the number chips per code, populating each matrix cell with OFC chip, and assigning the codes from the matrix to the devices. The asynchronous passive multi-tag system includes plural surface acoustic wave devices each producing a different OFC signal having the same number of chips and including a chip offset time delay, an algorithm for assigning OFCs to each device, and a transceiver to transmit an interrogation signal and receive OFC signals in response with minimal code collisions during transmission.

  11. Peripheral coding of taste

    PubMed Central

    Liman, Emily R.; Zhang, Yali V.; Montell, Craig

    2014-01-01

    Five canonical tastes, bitter, sweet, umami (amino acid), salty and sour (acid) are detected by animals as diverse as fruit flies and humans, consistent with a near universal drive to consume fundamental nutrients and to avoid toxins or other harmful compounds. Surprisingly, despite this strong conservation of basic taste qualities between vertebrates and invertebrates, the receptors and signaling mechanisms that mediate taste in each are highly divergent. The identification over the last two decades of receptors and other molecules that mediate taste has led to stunning advances in our understanding of the basic mechanisms of transduction and coding of information by the gustatory systems of vertebrates and invertebrates. In this review, we discuss recent advances in taste research, mainly from the fly and mammalian systems, and we highlight principles that are common across species, despite stark differences in receptor types. PMID:24607224

  12. IMP: A performance code

    NASA Astrophysics Data System (ADS)

    Dauro, Vincent A., Sr.

    IMP (Integrated Mission Program) is a simulation language and code used to model present and future Earth, Moon, or Mars missions. The profile is user controlled through selection from a large menu of events and maneuvers. A Fehlberg 7/13 Runge-Kutta integrator with error and step size control is used to numerically integrate the differential equations of motion (DEQ) of three spacecraft, a main, a target, and an observer. Through selection, the DEQ's include guided thrust, oblate gravity, atmosphere drag, solar pressure, and Moon gravity effects. Guide parameters for thrust events and performance parameters of velocity changes (Delta-V) and propellant usage (maximum of five systems) are developed as needed. Print, plot, summary, and debug files are output.

  13. Electromagnetic particle simulation codes

    NASA Technical Reports Server (NTRS)

    Pritchett, P. L.

    1985-01-01

    Electromagnetic particle simulations solve the full set of Maxwell's equations. They thus include the effects of self-consistent electric and magnetic fields, magnetic induction, and electromagnetic radiation. The algorithms for an electromagnetic code which works directly with the electric and magnetic fields are described. The fields and current are separated into transverse and longitudinal components. The transverse E and B fields are integrated in time using a leapfrog scheme applied to the Fourier components. The particle pushing is performed via the relativistic Lorentz force equation for the particle momentum. As an example, simulation results are presented for the electron cyclotron maser instability which illustrate the importance of relativistic effects on the wave-particle resonance condition and on wave dispersion.

  14. Telescope Adaptive Optics Code

    SciTech Connect

    Phillion, D.

    2005-07-28

    The Telescope AO Code has general adaptive optics capabilities plus specialized models for three telescopes with either adaptive optics or active optics systems. It has the capability to generate either single-layer or distributed Kolmogorov turbulence phase screens using the FFT. Missing low order spatial frequencies are added using the Karhunen-Loeve expansion. The phase structure curve is extremely dose to the theoreUcal. Secondly, it has the capability to simulate an adaptive optics control systems. The default parameters are those of the Keck II adaptive optics system. Thirdly, it has a general wave optics capability to model the science camera halo due to scintillation from atmospheric turbulence and the telescope optics. Although this capability was implemented for the Gemini telescopes, the only default parameter specific to the Gemini telescopes is the primary mirror diameter. Finally, it has a model for the LSST active optics alignment strategy. This last model is highly specific to the LSST

  15. 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.

  16. Transionospheric Propagation Code (TIPC)

    NASA Astrophysics Data System (ADS)

    Roussel-Dupre, Robert; Kelley, Thomas 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, delta times of arrival (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 DTOAs vs TECs for a specified pair of receivers.

  17. Diagonal Eigenvalue Unity (DEU) code for spectral amplitude coding-optical code division multiple access

    NASA Astrophysics Data System (ADS)

    Ahmed, Hassan Yousif; Nisar, K. S.

    2013-08-01

    Code with ideal in-phase cross correlation (CC) and practical code length to support high number of users are required in spectral amplitude coding-optical code division multiple access (SAC-OCDMA) systems. SAC systems are getting more attractive in the field of OCDMA because of its ability to eliminate the influence of multiple access interference (MAI) and also suppress the effect of phase induced intensity noise (PIIN). In this paper, we have proposed new Diagonal Eigenvalue Unity (DEU) code families with ideal in-phase CC based on Jordan block matrix with simple algebraic ways. Four sets of DEU code families based on the code weight W and number of users N for the combination (even, even), (even, odd), (odd, odd) and (odd, even) are constructed. This combination gives DEU code more flexibility in selection of code weight and number of users. These features made this code a compelling candidate for future optical communication systems. Numerical results show that the proposed DEU system outperforms reported codes. In addition, simulation results taken from a commercial optical systems simulator, Virtual Photonic Instrument (VPI™) shown that, using point to multipoint transmission in passive optical network (PON), DEU has better performance and could support long span with high data rate.

  18. Some easily analyzable convolutional codes

    NASA Technical Reports Server (NTRS)

    Mceliece, R.; Dolinar, S.; Pollara, F.; Vantilborg, H.

    1989-01-01

    Convolutional codes have played and will play a key role in the downlink telemetry systems on many NASA deep-space probes, including Voyager, Magellan, and Galileo. One of the chief difficulties associated with the use of convolutional codes, however, is the notorious difficulty of analyzing them. Given a convolutional code as specified, say, by its generator polynomials, it is no easy matter to say how well that code will perform on a given noisy channel. The usual first step in such an analysis is to computer the code's free distance; this can be done with an algorithm whose complexity is exponential in the code's constraint length. The second step is often to calculate the transfer function in one, two, or three variables, or at least a few terms in its power series expansion. This step is quite hard, and for many codes of relatively short constraint lengths, it can be intractable. However, a large class of convolutional codes were discovered for which the free distance can be computed by inspection, and for which there is a closed-form expression for the three-variable transfer function. Although for large constraint lengths, these codes have relatively low rates, they are nevertheless interesting and potentially useful. Furthermore, the ideas developed here to analyze these specialized codes may well extend to a much larger class.

  19. Effect of treatment with interferon-gamma and concanavalin A on the course of infection of mice with Salmonella typhimurium strain LT-2

    NASA Technical Reports Server (NTRS)

    Gould, Cheryl L.; Sonnenfeld, Gerald

    1987-01-01

    The effect of pretreatment of mice with 34 units/day, for five days, of interferon-gamma (IFN-gamma) on the course of infection with LD50 of Salmonella typhimurium strain LT-2 was assessed, using two IFN preparations: (1) a hybridoma supernatant fluid containing concanavalin-A-induced IFN-gamma activity and (2) pure murine IFN-gamma produced by recombinant DNA technology. The hybridoma supernatant-treated Salmonella-infected mice were found to die faster than mice treated only with Salmonella. Pure murine IFN-gamma was found to protect infected mice significantly, with 95 percent of mice surviving LD50 infection. In contrast, the Salmonella-infected mice treated with hybridoma supernatant were found to die faster than the Salmonella-infected untreated controls. Mice treated with concanavalin A alone prior to infection with S. typhimurium died more quickly than the untreated infected controls, suggesting that contamination with concanavalin A had a detrimental effect on mice survival.

  20. Strain analysis in the Sanandaj-Sirjan HP-LT Metamorphic Belt, SW Iran: Insights from small-scale faults and associated drag folds

    NASA Astrophysics Data System (ADS)

    Sarkarinejad, Khalil; Keshavarz, Saeede; Faghih, Ali

    2015-05-01

    This study is aimed at quantifying the kinematics of deformation using a population of drag fold structures associated with small-scale faults in deformed quartzites from Seh-Ghalatoun area within the HP-LT Sanandaj-Sirjan Metamorphic Belt, SW Iran. A total 30 small-scale faults in the quartzite layers were examined to determine the deformation characteristics. Obtained data revealed α0 (initial fault angle) and ω (angle between flow apophyses) are equal to 83° and 32°, respectively. These data yield mean kinematic vorticity number (Wm) equal to 0.79 and mean finite strain (Rs) of 2.32. These results confirm the relative contribution of ∼43% pure shear and ∼57% simple shear components, respectively. The strain partitioning inferred from this quantitative analysis is consistent with a sub-simple or general shear deformation pattern associated with a transpressional flow regime in the study area as a part of the Zagros Orogen. This type of deformation resulted from oblique convergence between the Afro-Arabian and Central-Iranian plates.