Science.gov

Sample records for ipns rapid cycling

  1. Observations of electrons in the Intense Pulse Neutron Source (IPNS) Rapid Cycling Synchrotron (RCS).

    SciTech Connect

    Dooling, J. C.; Brumwell, F. R.; Czyz, W. S.; Harkay, K. C.; Lien, M. K.; McMichael, G. E.

    2004-01-01

    In the process of accelerating protons from 50 to 450 MeV at 30 Hz, low-energy electrons are generated within the IPNS RCS vacuum chamber. Electrons from background gas stripping are detected using an Ionization Profile Monitor (IPM) to generate integrated, horizontal charge distributions of the single-harmonic bunch during acceleration. Recently, a Retarding Field Analyzer (RFA) was installed in the RCS to look for evidence of beam-induced multipacting by measuring the electrons ejected by the space charge of the beam. A wide-band, high-gain transimpedance amplifier has been built to observe time structure in the electron signal detected with the RFA. Though a noisy power supply prevented full I-V characteristics from being obtained, interesting features are observed; especially, after the period of phase modulation between the rf cavities that is deliberately introduced during the cycle. The phase modulation generates a longitudinal quadrupole oscillation in the bunch, which is believed to enhance beam stability. Preliminary results indicate that electron multipacting is not significant in the RCS. The effects of background gas neutralization are considered and details of the RFA measurements are presented.

  2. A Pinger Magnet System For Tune Measurements in the IPNS Rapid Cycling Synchrotron (RCS)

    SciTech Connect

    Dooling, J. C.; Donley, L.; Brumwell, F. R.; McMichael, G. E.; Wang, S.

    2006-11-20

    Pinger magnets for measuring horizontal and vertical tunes in the IPNS RCS have been constructed and installed. Reference horizontal tune data was collected using the extraction kicker magnets in December 2005. More recent data collected at the end of February 2006 with the dedicated pinger magnets confirms December measurements and provided simultaneous vertical tune information. Chromaticity variation with sextupole field strength is examined in an effort to optimize tune profiles.

  3. A pinger magnet system for tune measurements in the IPNS Rapid Cycling Synchrotron (RCS).

    SciTech Connect

    Dooling, J. C.; Donley, L. I.; Brumwell, F. R.; McMichael, G. E.; Wang, S.; Intense Pulsed Neutron Source

    2006-01-01

    Pinger magnets for measuring horizontal and vertical tunes in the IPNS RCS have been constructed and installed. Reference horizontal tune data was collected using the extraction kicker magnets in December 2005. More recent data collected at the end of February 2006 with the dedicated pinger magnets confirms December measurements and provided simultaneous vertical tune information. Chromaticity variation with sextupole field strength is examined in an effort to optimize tune profiles.

  4. Impedance considerations for the Intense Pulse Neutron Source (IPNS) Rapid Cycling Synchrotron (RCS).

    SciTech Connect

    Brumwell, F. R.; Dooling, J. C.; McMichael, G. E.

    1999-09-08

    The use of Second Harmonic (SH) rf is being investigated to increase the Rapid Cycling Synchrotron (RCS) current limit. Hofmann-Pedersen distributions are employed to provide analytical guidance. The SH phase {theta}, is optimized using a numerical analysis to maximize transmission and minimize instabilities. The effect of the RCS stainless steel liner on the impedance of the machine is also discussed.

  5. Bunch stabilization using rf phase modulation in the intense pulse neutron source (IPNS) rapid cycling synchrotron (RCS)

    SciTech Connect

    Dooling, J. C.; Brumwell, F. R.; McMichael, G. E.

    1999-12-03

    Phase modulation (PM) is used to increase the current limit in the IPNS RCS. A device referred to as a scrambler introduces a small oscillating phase between the two RCS rf cavities at approximately twice the synchrotron frequency, f{sub s}. The modulation introduced by the scrambler generates longitudinal oscillations in the bunch at 2f{sub s}. Modulations in the bunch are also observed transversely indicating a coupling between longitudinal and transverse motion. Comparing PM with amplitude modulation (AM), coupling to the beam is roughly equivalent at 2f{sub s}.

  6. Bunch stabilization using rf phase modulation in the Intense Pulse Neutron Source (IPNS) Rapid Cycling Synchrotron (RCS).

    SciTech Connect

    Brumwell, F. R.; Dooling, J. C.; McMichael, G. E.

    1999-09-01

    Phase modulation (PM) is used to increase the current limit in the IPNS RCS. A device referred to as a scrambler introduces a small oscillating phase between the two RCS rf cavities at approximately twice the synchrotrons frequency, f{sub s}. The modulation introduced by the scrambler generates longitudinal oscillations in the bunch at 2f{sub s}. Modulations in the bunch are also observed transversely indicating a coupling between longitudinal and transverse motion. Comparing PM with amplitude modulation (AM), coupling to the beam is roughly equivalent at 2f{sub s}.

  7. IPNS progress report 2001-2006.

    SciTech Connect

    Marzec, B.

    2006-11-27

    In August 1981, the proton beam from the rapid cycling synchrotron (RCS) was first delivered to the Intense Pulsed Neutron Source (IPNS) neutron scattering target and now, in June 2006, it is with great joy that we celebrate the impending 25th anniversary of this event. This edition of the IPNS Progress Report will focus on the development and scientific accomplishments of the past 5 years, since our last Progress Report, but with some mention of the 25 years of IPNS experience. It is appropriate at this anniversary date to recall some of the more significant historic events that have led to the present IPNS and discuss some of the plans that will lead to even more successes. Below is a brief chronology that captures some of the developments of IPNS: 8/4/81 - First beam delivered to the neutron scattering target; 6/10/84 - IPNS produced its one billionth neutron pulse; 1/10/85 - Installed world's first solid methane moderator; 6/30/87 - 1000th experiment performed at IPNS; 9/19/87 - IPNS produced its two billionth neutron pulse; 11/20/91 - 2000th experiment performed at IPNS; 4/17/04 - IPNS produced its eight billionth neutron pulse; and 8/19/05 - 7000th experiment performed at IPNS. During the past 5 years, several significant source and instrument developments have taken place. Most of these are discussed in more detail elsewhere in the report, but three of the ones most visible to users are mentioned here.

  8. Rapid Cycling and Its Treatment

    MedlinePlus

    ... may be rapid, ultra-rapid or ultradian cycling. Biological rhythm disturbances: This theory proposes that people with rapid cycling have daily biological rhythms that are out of sync with typical “ ...

  9. Rapid cycling superconducting magnets

    NASA Astrophysics Data System (ADS)

    Fabbricatore, P.; Farinon, S.; Gambardella, U.; Greco, M.; Volpini, G.

    2006-04-01

    The paper deals with the general problematic related to the development of fast cycled superconducting magnets for application in particle accelerator machines. Starting from the requirements of SIS300 synchrotron under design at GSI and an envisaged future Super-SPS injector at CERN, it is shown which developments are mandatory in the superconducting wire technology and in the magnet design field.

  10. Vertical Instability at IPNS RCS.

    SciTech Connect

    Wang, S.; Brumwell, F. R.; Dooling, J. C.; Harkay, K. C.; Kustom, R.; McMichael, G. E.; Middendorf, M. E.; Nassiri, A.; Accelerator Systems Division

    2008-01-01

    The rapid cycling synchrotron (RCS) of the intense pulsed neutron source (IPNS) at ANL accelerates > 3.0 times 10{sup 12} protons from 50 MeV to 450 MeV with 30-Hz repetition frequency. During the acceleration cycle, the rf frequency varies from 2.21 MHz to 5.14 MHz. Presently, the beam current is limited by a vertical instability. By analyzing turn-by-turn beam position monitor (BPM) data, large- amplitude mode 0 and mode 1 vertical beam centroid oscillations were observed in the later part of the acceleration cycle. The oscillations start in the tail of the bunch, build up, and remain localized in the tail half of the bunch. This vertical instability was compared with a head-tail instability that was intentionally induced in the RCS by adjusting the trim sextupoles. It appears that our vertical instability is not a classical head-tail instability [1]. More data analysis and experiments were performed to characterize the instability.

  11. Impedance considerations for the Intense Pulsed Neutron Source (IPNS) Rapid Cycling Synchrotron (RCS)

    SciTech Connect

    Dooling, J. C.; Brumwell, F. R.; McMichael, G. E.

    1999-12-03

    The use of Second Harmonic (SH) rf is being investigated to increase the RCS current limit. Hofmann-Pedersen distributions are employed to provide analytical guidance. The SH phase {theta}, is optimized using a numerical analysis to maximize transmission and minimize instabilities. The effect of the RCS stainless steel liner on the impedance of the machine is also discussed.

  12. IPNS upgrade: A feasibility study

    SciTech Connect

    1995-04-01

    Many of Argonne National Laboratory`s (ANL`s) scientific staff members were very active in R&D work related to accelerator-based spoliation sources in the 1970s and early 1980s. In 1984, the Seitz/Eastman Panel of the National Academy of Sciences reviewed U.S. materials science research facilities. One of the recommendations of this panel was that the United States build a reactor-based steady-state source, the Advanced Neutron Source (ANS), at Oak Ridge National Laboratory. Subsequently, R&D activities related to the design of an accelerator-based source assumed a lower priority. The resumption of pulsed-source studies in this country started simultaneously with design activities in Europe aimed at the European Spallation Source (ESS). The European Community funded a workshop in September 1991 to define the parameters of the ESS. Participants in this workshop included both accelerator builders and neutron source users. A consortium of European countries has proposed to build a 5-MW pulsed source, and a feasibility study is currently under way. Soon after the birth of the ESS, a small group at ANL set about bringing themselves up to date on pulsed-source information since 1984 and studied the feasibility of upgrading ANL`s Intense Pulsed Neutron Source (IPNS) to 1 MW by means of a rapidly cycling synchrotron that could be housed, along with its support facilities, in existing buildings. In early 1993, the Kohn panel recommended that (1) design and construction of the ANS should be completed according to the proposed project schedule and (2) development of competitive proposals for cost-effective design and construction of a 1-MW pulsed spallation source should be authorized immediately.

  13. IPNS enriched uranium booster target

    SciTech Connect

    Schulke, A.W. Jr.

    1985-01-01

    Since startup in 1981, IPNS has operated on a fully depleted /sup 238/U target. With the booster as in the present system, high energy protons accelerated to 450 MeV by the Rapid Cycling Synchrotron are directed at the target and by mechanisms of spallation and fission of the uranium, produce fast neutrons. The neutrons from the target pass into adjacent moderator where they slow down to energies useful for spectroscopy. The target cooling systems and monitoring systems have operated very reliably and safely during this period. To provide higher neutron intensity, we have developed plans for an enriched uranium (booster) target. HETC-VIM calculations indicate that the target will produce approx.90 kW of heat, with a nominal x5 gain (k/sub eff/ = 0.80). The neutron beam intensity gain will be a factor of approx.3. Thermal-hydraulic and heat transport calculations indicate that approx.1/2 in. thick /sup 235/U discs are subject to about the same temperatures as the present /sup 238/U 1 in. thick discs. The coolant will be light demineralized water (H/sub 2/O) and the coolant flow rate must be doubled. The broadening of the fast neutron pulse width should not seriously affect the neutron scattering experiments. Delayed neutrons will appear at a level about 3% of the total (currently approx.0.5%). This may affect backgrounds in some experiments, so that we are assessing measures to control and correct for this (e.g., beam tube choppers). Safety analyses and neutronic calculations are nearing completion. Construction of the /sup 235/U discs at the ORNL Y-12 facility is scheduled to begin late 1985. The completion of the booster target and operation are scheduled for late 1986. No enriched uranium target assembly operating at the projected power level now exists in the world. This effort thus represents an important technological experiment as well as being a ''flux enhancer''.

  14. Conducting IPN actuators for biomimetic vision system

    NASA Astrophysics Data System (ADS)

    Festin, Nicolas; Plesse, Cedric; Chevrot, Claude; Teyssié, Dominique; Pirim, Patrick; Vidal, Frederic

    2011-04-01

    In recent years, many studies on electroactive polymer (EAP) actuators have been reported. One promising technology is the elaboration of electronic conducting polymers based actuators with Interpenetrating Polymer Networks (IPNs) architecture. Their many advantageous properties as low working voltage, light weight and high lifetime (several million cycles) make them very attractive for various applications including robotics. Our laboratory recently synthesized new conducting IPN actuators based on high molecular Nitrile Butadiene Rubber, poly(ethylene oxide) derivative and poly(3,4-ethylenedioxithiophene). The presence of the elastomer greatly improves the actuator performances such as mechanical resistance and output force. In this article we present the IPN and actuator synthesis, characterizations and design allowing their integration in a biomimetic vision system.

  15. The IPNS second harmonic RF upgrade.

    SciTech Connect

    Middendorf, M. E.; Brumwell, F. R.; Dooling, J. C.; Horan, D.; Kustom, R. L.; Lien, M. K.; McMichael, G. E.; Moser, M. R.; Nassiri, A.; Wang, S.; Accelerator Systems Division

    2008-01-01

    The intense pulsed neutron source (IPNS) rapid cycling synchrotron (RCS) is used to accelerate protons from 50 MeV to 450 MeV, at a repetition rate of 30 Hz. The original ring design included two identical rf systems, each consisting of an accelerating cavity, cavity bias supply, power amplifiers and low-level analog electronics. The original cavities are located 180 degrees apart in the ring and provide a total peak accelerating voltage of {approx}21 kV over the 2.21-MHz to 5.14-MHz revolution frequency sweep. A third rf system has been constructed and installed in the RCS. The third rf system is capable of operating at the fundamental revolution frequency for the entire acceleration cycle, providing an additional peak accelerating voltage of up to {approx}11 kV, or at the second harmonic of the revolution frequency for the first {approx}4 ms of the acceleration cycle, providing an additional peak voltage of up to {approx}11 kV for bunch shape control. We describe here the hardware implementation and operation to date of the third rf cavity in the second harmonic mode.

  16. The investigation of injection timing for the IPNS RCS.

    SciTech Connect

    Wang, S.; Brmwell, F. R.; Dooling, J. C.; Kustom, R.; McMichael, G. E.; Middendorf, M. E.; Accelerator Systems Division

    2008-01-01

    The Rapid Cycling Synchrotron (RCS) of the Intense Pulsed Neutron Source (IPNS) at ANL accelerates > 3.0 times 10{sup 12} protons from 50 MeV to 450 MeV with 30-Hz repetition frequency. During each acceleration cycle, the RF varies from 2.21 MHz to 5.14 MHz. In order to improve capture efficiency, we varied the injection timing and the early RF voltage profiles. The experimental results are compared with simulation results obtained with the 1-D tracking code, CAPTURE. This allowed us to optimize injection time and the RF voltage profile for better capture efficiency. An optimized injection time and RF voltage profile was found that resulted in raising the capture efficiency from 85.1% to 88.6%. These studies have now also been expanded to include second harmonic RF during the capture and initial acceleration cycle in the RCS.

  17. Rapid-Cycling Synchrotron extraction-kicker magent-drive system

    SciTech Connect

    Suddeth, D.E.; Volk, G.J.

    1981-01-01

    The Rapid-Cycling Synchrotron (RCS) accelerator of the Intense Pulsed Neutron Source-I (IPNS-I) at Argonne National Laboratory utilizes a fast kicker magnet to provide single-turn extraction for a 500-MeV proton beam at a 30 Hz rate. The single-turn, 0.89-m-long ferrite magnet is broken up into two identical cells with four individual windings. Each winding requires a 4863-A magnetizing current into a 7.0-..cap omega.. load with a rise time of less than 100 ns and a flattop of about 140 ns. Pulse forming network (PFN) charging and switching techniques along with the components used will be described.

  18. Rapid cycling with true potato seed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rapid generation cycling via true seed production can increase the efficiency of potato breeding programs and genetics studies. This study was carried out to determine the fruit ripening and seed treatment conditions needed for generating true potato seed (TPS) with a high germination rate in a shor...

  19. Freeze-Drying Makes Improved IPN And Semi-IPN Polymers

    NASA Technical Reports Server (NTRS)

    Pater, Ruth H.; Smith, Ricky E.; Razon, Ruperto T.; Hansen, Marion G.; Hsiung, Hahn J.; Soucek, Mark D.

    1993-01-01

    Novel process developed for production of interpenetrating polymer networks (IPN's) or semi-IPN's with greater fracture toughness and resistance to microcracks. Process controls degree of phase separation in IPN's. In experiment, IPN's and semi-IPN's formed by dissolving constituents in another common solvent in traditional method. Resins and composite materials produced were tested for both traditional and freeze-drying processes. Glass-transition temperatures and data from dynamic mechanical tests of freeze-dried IPN's and semi-IPN's demonstrated freeze-drying process provided much improved IPN's and semi-IPN's.

  20. Methods and compositions for rapid thermal cycling

    SciTech Connect

    Beer, Neil Reginald; Benett, William J.; Frank, James M.; Deotte, Joshua R.; Spadaccini, Christopher

    2015-10-27

    The rapid thermal cycling of a material is targeted. A microfluidic heat exchanger with an internal porous medium is coupled to tanks containing cold fluid and hot fluid. Fluid flows alternately from the cold tank and the hot tank into the porous medium, cooling and heating samples contained in the microfluidic heat exchanger's sample wells. A valve may be coupled to the tanks and a pump, and switching the position of the valve may switch the source and direction of fluid flowing through the porous medium. A controller may control the switching of valve positions based on the temperature of the samples and determined temperature thresholds. A sample tray for containing samples to be thermally cycled may be used in conjunction with the thermal cycling system. A surface or internal electrical heater may aid in heating the samples, or may replace the necessity for the hot tank.

  1. Rapid Cycling Synchrotron Option for Project X

    SciTech Connect

    Chou, Weiren

    2009-12-01

    This paper presents an 8 GeV Rapid Cycling Synchrotron (RCS) option for Project X. It has several advantages over an 8 GeV SC linac. In particular, the cost could be lower. With a 2 GeV 10 mA pulsed linac as injector, the RCS would be able to deliver 4 MW beam power for a muon collider. If, instead, a 2 GeV 1 mA CW linac is used, the RCS would still be able to meet the Project X requirements but it would be difficult for it to serve a muon collider due to the very long injection time.

  2. Power Supply Systems for Rapid Cycling Synchrotron

    NASA Astrophysics Data System (ADS)

    Watanabe, Yasuhiro; Adachi, Toshikazu; Someya, Hirohiko; Koseki, Shoichiro; Ogawa, Shinichi

    JAEA and KEK are jointly constructing a high intensity proton accelerator project J-PARC. Its main accelerator is 3GeV rapid cycling synchrotron (RCS). Two types of resonant excitation systems, parallel and cascade, are introduced to excite DC biased 25Hz AC currents through its main magnets. The parallel excitation is adopted for dipole magnets power supply system, and the cascade excitations are adopted for seven family quadrupole magnets systems. In this paper, two systems are investigated and analyzed, and it is explained why different types are adopted to each system. Authors believe that such hybrid exciting systems are most suitable for high power RCS.

  3. Nitrogen cycling. Rapid nitrous oxide cycling in the suboxic ocean.

    PubMed

    Babbin, Andrew R; Bianchi, Daniele; Jayakumar, Amal; Ward, Bess B

    2015-06-01

    Nitrous oxide (N2O) is a powerful greenhouse gas and a major cause of stratospheric ozone depletion, yet its sources and sinks remain poorly quantified in the oceans. We used isotope tracers to directly measure N2O reduction rates in the eastern tropical North Pacific. Because of incomplete denitrification, N2O cycling rates are an order of magnitude higher than predicted by current models in suboxic regions, and the spatial distribution suggests strong dependence on both organic carbon and dissolved oxygen concentrations. Furthermore, N2O turnover is 20 times higher than the net atmospheric efflux. The rapid rate of this cycling coupled to an expected expansion of suboxic ocean waters implies future increases in N2O emissions. PMID:26045434

  4. Quadrupole magnet for a rapid cycling synchrotron

    SciTech Connect

    Witte, H.; Berg, J. S.

    2015-05-03

    Rapid Cycling Synchrotrons (RCS) feature interleaved warm and cold dipole magnets; the field of the warm magnets is used to modulate the average bending field depending on the particle energy. It has been shown that RCS can be an attractive option for fast acceleration of particles, for example, muons, which decay quickly. In previous studies it was demonstrated that in principle warm dipole magnets can be designed which can provide the required ramp rates, which are equivalent to frequencies of about 1 kHz. To reduce the losses it is beneficial to employ two separate materials for the yoke; it was also shown that by employing an optimized excitation coil geometry the eddy current losses are acceptable. In this paper we show that the same principles can be applied to quadrupole magnets targeting 30 T/m with a repetition rate of 1kHz and good field quality.

  5. Proposed second harmonic acceleration system for the intense pulsed neutron source rapid cycling synchrotron

    SciTech Connect

    Norem, J.; Brandeberry, F.; Rauchas, A.

    1983-01-01

    The Rapid Cycling Synchrotron (RCS) of the Intense Pulsed Neutron Source (IPNS) operating at Argonne National Laboratory is presently producing intensities of 2 to 2.5 x 10/sup 12/ protons per pulse (ppp) with the addition of a new ion source. This intensity is close to the space charge limit of the machine, estimated at approx.3 x 10/sup 12/ ppp, depending somewhat on the available aperture. With the present good performance in mind, accelerator improvements are being directed at: (1) increasing beam intensities for neutron science; (2) lowering acceleration losses to minimize activation; and (3) gaining better control of the beam so that losses can be made to occur when and where they can be most easily controlled. On the basis of preliminary measurements, we are now proposing a third cavity for the RF systems which would provide control of the longitudinal bunch shape during the cycle which would permit raising the effective space charge limit of the accelerator and reducing losses.

  6. Rapid-cycling bipolar disorder: cross-national community study

    PubMed Central

    Lee, Sing; Tsang, Adley; Kessler, Ronald C.; Jin, Robert; Sampson, Nancy; Andrade, Laura; Karam, Elie G.; Mora, Maria Elena Medina; Merikangas, Kathleen; Nakane, Yoshibumi; Popovici, Daniela Georgeta; Posada-Villa, Jose; Sagar, Rajesh; Wells, J. Elisabeth; Zarkov, Zahari; Petukhova, Maria

    2010-01-01

    Background The epidemiology of rapid-cycling bipolar disorder in the community is largely unknown. Aims To investigate the epidemiological characteristics of rapid-cycling and non-rapid-cycling bipolar disorder in a large cross-national community sample. Method The Composite International Diagnostic Interview (CIDI version 3.0) was used to examine the prevalence, severity, comorbidity, impairment, suicidality, sociodemographics, childhood adversity and treatment of rapid-cycling and non-rapid-cycling bipolar disorder in ten countries (n = 54 257). Results The 12-month prevalence of rapid-cycling bipolar disorder was 0.3%. Roughly a third and two-fifths of participants with lifetime and 12-month bipolar disorder respectively met criteria for rapid cycling. Compared with the non-rapid-cycling, rapid-cycling bipolar disorder was associated with younger age at onset, higher persistence, more severe depressive symptoms, greater impairment from depressive symptoms, more out-of-role days from mania/hypomania, more anxiety disorders and an increased likelihood of using health services. Associations regarding childhood, family and other sociodemographic correlates were less clear cut. Conclusions The community epidemiological profile of rapid-cycling bipolar disorder confirms most but not all current clinically based knowledge about the illness. PMID:20194545

  7. IPNS-I chopper spectrometers

    SciTech Connect

    Price, D.L.; Carpenter, J.M.; Pelizzari, C.A.; Sinha, S.K.; Bresof, I.; Ostrowski, G.E.

    1982-01-01

    We briefly describe the layout and operation of the two chopper experiments at IPNS-I. The recent measurement on solid /sup 4/He by Hilleke et al. provides examples of time-of-flight data from the Low Resolution Chopper Spectrometer.

  8. Cognitive-Behavioral Therapy for Rapid Cycling Bipolar Disorder

    ERIC Educational Resources Information Center

    Reilly-Harrington, Noreen A.; Knauz, Robert O.

    2005-01-01

    This article describes the application of cognitive-behavioral therapy (CBT) to the treatment of rapid cycling bipolar disorder. Between 10% and 24% of bipolar patients experience a rapid cycling course, with 4 or more mood episodes occurring per year. Characterized by nonresponse to standard mood-stabilizing medications, rapid cyclers are…

  9. The IPNS RCS RF-system third cavity upgrade.

    SciTech Connect

    Middendorf, M.E.; Brumwell, F. R.; Dooling, J.C.; Lein, M. K.; McMichael, G. E.; Intense Pulsed Neutron Source

    2001-12-01

    The IPNS RCS is a rapid cycling synchrotron used to accelerate protons from 50 MeV to 450 MeV, 30 times per second. Currently, two single-gap, ferrite-loaded coaxial cavities, located 180 degrees apart, provide a total peak accelerating voltage of approximately 21 kV over the 2.2 MHz to 5.1 MHz revolution frequency band. An amplifier chain, which includes a 2 kW predriver, a 20 kW driver and a 100 kW final, drives each cavity. A third RF system, consisting of a cavity, cavity bias supply, and amplifier chain, is currently under construction. When complete, this upgrade will provide flexibility in operation that is expected to enhance reliability (i.e., three cavity operation at higher total accelerating voltage, three cavity operation at lower voltage per cavity, or two cavity operation with an on-line spare). In addition, the third cavity will provide an experimental station for second harmonic RF cavity studies. We report progress to date.

  10. Rapid carbon cycling in the oligotrophic ocean

    NASA Astrophysics Data System (ADS)

    Duarte, C. M.; Agustí, S.

    2011-12-01

    The dynamics of organic carbon production, release and bacterial use was examined across a range of communities spanning from highly oligotrophic ones in the Subtropical Atlantic Ocean, mesotrophic ones in the Mediterranean Sea and productive ones in the Northern African upwelling and the Southern Ocean. A comparative analysis of experiments examining total and particulate organic carbon production across a range of time scales (15 min to 24 h) for 20 communities with contrasting phytoplankton cell status, as assessed by cell lysis rates, and the use of a simple inverse model was used to resolve patterns of carbon flow in the microbial food web. Communities in productive ocean waters accumulated organic carbon over hourly time scales, whereas only a small fraction of net primary production accumulated in communities from oligotrophic waters. These communities supported high phytoplankton cell lysis rates leading to a rapid flux of organic carbon to bacteria, which had high affinity for phytoplankton-derived carbon, much of which was rapidly respired. Conventional assessments of primary production in the oligotrophic ocean severely underestimate net phytoplankton production, as carbon flow in microbial communities from oligotrophic ocean waters occurs within short (minutes) time scales. This explains difficulties to reconcile estimates of primary production with independent estimates of carbon use by bacteria in oligotrophic marine ecosystems.

  11. Rapid lithification masks the Venus sedimentary cycle

    NASA Astrophysics Data System (ADS)

    Ghail, R.

    2015-10-01

    Venera lander data are usually assumed to indicate basaltic lavas but a significant fraction of the rock material must be volatiles, such as sulphur, implying at least strongly weathered basalts. The lander images most closely resemble sedimentary material, with layered strata (which may be pyroclastic in origin)that are sometimes broken into cobbles and fine grained sediment. The Magellan SAR was relatively insensitive to loose fine-grained material under Venus surface conditions but the reprocessed data reveal a range of weathering processes, particularly at higher elevations, and mass wasting of steep slopes. Mean wind speeds are strongly altitude dependent and are able to erode and transport material throughout the highland regions. In some areas, this material is deposited on adjacent plains where, under the extreme Venus surface conditions, lithification is an apparently rapid process. Thus the largely featureless plains may not be igneous at all but sedimentary in origin. The settling out and lithification of sedimentary material is consistent with observed crater degradation, in which low-lying crater floors are infilled first.

  12. LIFE CYCLE BIOASSAY FOR ASSESSMENT OF THE EFFECTS OF TOXIC CHEMICALS USING RAPID CYCLING OF BRASSICA

    EPA Science Inventory

    Initial evaluation of a new plant life cycle bioassay for the assessment of the effects of toxic chemicals is presented. he bioassay features a rapid cycling Brassica species that can complete its life cycle in as little as 36 days. he herbicide dalapon (2,2 dichloropropionic aci...

  13. A rapid-temperature-cycling apparatus for oxidation testing

    SciTech Connect

    Cabrera, A.L.; Kirner, J.F. )

    1991-06-01

    An oxidation test with rapid temperature cycling was developed to evaluate small coated parts. The samples in the form of wire or foils are resistively heated with a high-current AC power supply, allowing fast heating and cooling of the samples. Fast temperature cycling of the samples permits to complete more than 100 cycles in one day. A variety of steels coated with silicon diffusion coatings were tested and the results compared with oxidation via traditional thermal cycling. The test accurately predicts enhanced performance for siliconized 1010 steel, an increase by a factor of three for the life of siliconized 302 stainless steel, and an inadequate siliconized coating for 410 stainless steel. Details of the rapid temperature cycling apparatus as well as testing of the coated steels are described in the paper.

  14. Rapid cycling medical synchrotron and beam delivery system

    DOEpatents

    Peggs, Stephen G.; Brennan, J. Michael; Tuozzolo, Joseph E.; Zaltsman, Alexander

    2008-10-07

    A medical synchrotron which cycles rapidly in order to accelerate particles for delivery in a beam therapy system. The synchrotron generally includes a radiofrequency (RF) cavity for accelerating the particles as a beam and a plurality of combined function magnets arranged in a ring. Each of the combined function magnets performs two functions. The first function of the combined function magnet is to bend the particle beam along an orbital path around the ring. The second function of the combined function magnet is to focus or defocus the particle beam as it travels around the path. The radiofrequency (RF) cavity is a ferrite loaded cavity adapted for high speed frequency swings for rapid cycling acceleration of the particles.

  15. Robust solid polymer electrolyte for conducting IPN actuators

    NASA Astrophysics Data System (ADS)

    Festin, Nicolas; Maziz, Ali; Plesse, Cédric; Teyssié, Dominique; Chevrot, Claude; Vidal, Frédéric

    2013-10-01

    Interpenetrating polymer networks (IPNs) based on nitrile butadiene rubber (NBR) as first component and poly(ethylene oxide) (PEO) as second component were synthesized and used as a solid polymer electrolyte film in the design of a mechanically robust conducting IPN actuator. IPN mechanical properties and morphologies were mainly investigated by dynamic mechanical analysis and transmission electron microscopy. For 1-ethyl-3-methylimidazolium bis-(trifluoromethylsulfonyl)-imide (EMITFSI) swollen IPNs, conductivity values are close to 1 × 10-3 S cm-1 at 25 ° C. Conducting IPN actuators have been synthesized by chemical polymerization of 3,4-ethylenedioxythiophene (EDOT) within the PEO/NBR IPN. A pseudo-trilayer configuration has been obtained with PEO/NBR IPN sandwiched between two interpenetrated PEDOT electrodes. The robust conducting IPN actuators showed a free strain of 2.4% and a blocking force of 30 mN for a low applied potential of ±2 V.

  16. Preparation and characterization of IPN hydrogels composed of chitosan and gelatin cross-linked by genipin.

    PubMed

    Cui, Li; Jia, Junfang; Guo, Yi; Liu, Yun; Zhu, Ping

    2014-01-01

    The interpenetrating polymer networks (IPN) hydrogels based on chitosan and gelatin using genipin as the cross-linker were prepared and characterized. The IPN formation of the genipin-cross-linked chitosan/gelatin hydrogel was confirmed by means of the instrinsic viscosity measurement, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and the ninhydrin assays. The instrinsic viscosity measurement, FT-IR and SEM suggested that chitosan and gelatin were miscible in the molecular level. The miscibility leads to the formation of IPN after cross-linking. FT-IR also examined the cross-linking mechanism of genipin with primary amino groups. The degree of cross-linking increased with increase genipin concentration. Swelling results revealed that the IPN hydrogels are pH-sensitive, exhibiting reversibility and rather rapidly response in swelling to pH changes. It is expected this IPN hydrogel has potential as controlled drug delivery system or as alternative sorbents for biomedical and environmental use as pH altered. PMID:24274476

  17. Towards temperature driven forward osmosis desalination using Semi-IPN hydrogels as reversible draw agents.

    PubMed

    Cai, Yufeng; Shen, Wenming; Loo, Siew Leng; Krantz, William B; Wang, Rong; Fane, Anthony G; Hu, Xiao

    2013-07-01

    We report a study to explore new materials and a new concept for temperature driven quasi-continuous desalination using hydrogels as draw agents in forward osmosis (FO). This concept is enabled by the design and preparation of thermally responsive hydrogels having a semi-interpenetrating network (semi-IPN) structure. Thermally responsive semi-IPN hydrogels were synthesized by polymerization of N-isopropylacrylamide (NIPAm) in the presence of polysodium acrylate (PSA) or polyvinyl alcohol (PVA). Their functions as draw agents in FO were systematically studied and compared with hydrogels prepared from the PNIPAm homopolymer or the NIPAM-SA copolymer. While the semi-IPN hydrogels displayed the desirable balanced thermally responsive swelling and dewatering behavior, the NIPAm-SA copolymer hydrogels were found to have poor dewatering behavior, making them unsuitable for a continuous temperature driven desalination process. At 40 °C, the semi-IPN hydrogels rapidly release nearly 100% of the water absorbed during the FO drawing process carried out at room temperature. Results clearly indicate the potential of semi-IPN hydrogels as semi-solid draw agents in the FO process, in which quasi-continuous desalination could be achieved by cyclic heating and cooling within a moderate temperature change. PMID:23726714

  18. Diagnostic investigation of tune and tune shift in the IPNS RCS.

    SciTech Connect

    Dooling, J. C.; Brumwell, F. R.; McMichael, G. E.

    2002-06-10

    The Intense Pulse Neutron Source (IPNS) Rapid Cycling Synchrotron (RCS) accelerates 50 MeV protons to 450 MeV 30 times per second for spallation neutron production. Average current from the RCS has recently exceeded 16 {micro}A with peak instantaneous current approaching 15 A. The RCS makes efficient use of 21 kV of RF accelerating voltage and uses phase-modulation between the two rf cavities to damp vertical instabilities. Split-ring electrodes in the ring suggest an anomalous tune shift that increases with time in the acceleration cycle. Based on a background gas pressure of 1 {micro}Torr, the neutralization time for the beam is approximately 0.5 ms at injection suggesting the beam becomes fully neutralized relatively quickly in the cycle. Over-neutralization of the beam can lead to a positive tune shift that is presumably incoherent. Studies are underway to characterize the ionization within the RCS using the existing Profile and Position System (PAPS) and a newly installed Retarding Field Analyzer (RFA). Also a newly installed fast, deep-memory digitizing oscilloscope allows the entire history of a single acceleration cycle to be recorded from all four components of the split ring electrodes simultaneously at a rate of 250 MS/s.

  19. Sample-related peripheral equipment at IPNS

    SciTech Connect

    Bohringer, D.E.; Crawford, R.K.

    1985-01-01

    This paper describes samples environment equipment provided by IPNS to visiting users and staff scientists. Of the twelve horizontal neutron beam stations, (ten now operational, two under construction) all use one or more form of such support equipment. An in-house support group devotes a significant fraction of its time to development, calibration, and maintenance of this equipment.

  20. Rapid nitrous oxide cycling in the suboxic ocean

    NASA Astrophysics Data System (ADS)

    Babbin, Andrew R.; Bianchi, Daniele; Jayakumar, Amal; Ward, Bess B.

    2015-06-01

    Nitrous oxide (N2O) is a powerful greenhouse gas and a major cause of stratospheric ozone depletion, yet its sources and sinks remain poorly quantified in the oceans. We used isotope tracers to directly measure N2O reduction rates in the eastern tropical North Pacific. Because of incomplete denitrification, N2O cycling rates are an order of magnitude higher than predicted by current models in suboxic regions, and the spatial distribution suggests strong dependence on both organic carbon and dissolved oxygen concentrations. Furthermore, N2O turnover is 20 times higher than the net atmospheric efflux. The rapid rate of this cycling coupled to an expected expansion of suboxic ocean waters implies future increases in N2O emissions.

  1. Ceramic thermal barrier coating for rapid thermal cycling applications

    DOEpatents

    Scharman, Alan J.; Yonushonis, Thomas M.

    1994-01-01

    A thermal barrier coating for metal articles subjected to rapid thermal cycling includes a metallic bond coat deposited on the metal article, at least one MCrAlY/ceramic layer deposited on the bond coat, and a ceramic top layer deposited on the MCrAlY/ceramic layer. The M in the MCrAlY material is Fe, Ni, Co, or a mixture of Ni and Co. The ceramic in the MCrAlY/ceramic layer is mullite or Al.sub.2 O.sub.3. The ceramic top layer includes a ceramic with a coefficient of thermal expansion less than about 5.4.times.10.sup.-6 .degree.C.sup.-1 and a thermal conductivity between about 1 J sec.sup.-1 m.sup.-1 .degree.C.sup.-1 and about 1.7 J sec.sup.-1 m.sup.-1 .degree.C.sup.-1.

  2. Rapid Cycling Synchrotron (RCS) sngle-stage kicker magnet

    SciTech Connect

    Suddeth, D.E.; Volk, G.J.

    1980-01-01

    A new single stage kicker magnet system is designed and is being fabricated for the RCS accelerator of the Intense Pulsed Neutron Source (IPNS-I) at the Argonne National Laboratory. This system will replace the two stage kicker in present use. The magnet aperture is 10 cm wide by 5 cm high and the magnetic length is 0.89 m. The magnetic field intensity is 0.1021 T for a 25 milliradian kick to the 500 MeV proton beam. A field rise time (10 to 90%) of 80 ns and a flattop of 100 ns is needed. The magnetic field fall time is not critical so a lumped parameter magnet with a 7.2 ohm load will be used. The electric current required through the single turn magnet is 4863 A. A new energy storage and switching system is designed and is being fabricated for energizing the magnets. The techniques and hardware used will be described along with some of the experience gained in the use of the two stage system which will help to improve the new design.

  3. On-line DNA analysis system with rapid thermal cycling

    DOEpatents

    Swerdlow, H.P.; Wittwer, C.T.

    1999-08-10

    This application describes an apparatus particularly suited for subjecting biological samples to any necessary sample preparation tasks, subjecting the sample to rapid thermal cycling, and then subjecting the sample to subsequent on-line analysis using one or more of a number of analytical techniques. The apparatus includes a chromatography device including an injection means, a chromatography pump, and a chromatography column. In addition, the apparatus also contains a capillary electrophoresis device consisting of a capillary electrophoresis column with an inlet and outlet end, a means of injection, and means of applying a high voltage to cause the differential migration of species of interest through the capillary column. Effluent from the liquid chromatography column passes over the inlet end of the capillary electrophoresis column through a tee structure and when the loading of the capillary electrophoresis column is desired, a voltage supply is activated at a precise voltage and polarity over a specific duration to cause sample species to be diverted from the flowing stream to the capillary electrophoresis column. A laser induced fluorescence detector preferably is used to analyze the products separated while in the electrophoresis column. 6 figs.

  4. On-line DNA analysis system with rapid thermal cycling

    DOEpatents

    Swerdlow, Harold P.; Wittwer, Carl T.

    1999-01-01

    An apparatus particularly suited for subjecting biological samples to any necessary sample preparation tasks, subjecting the sample to rapid thermal cycling, and then subjecting the sample to subsequent on-line analysis using one or more of a number of analytical techniques. The apparatus includes a chromatography device including an injection means, a chromatography pump, and a chromatography column. In addition, the apparatus also contains a capillary electrophoresis device consisting of a capillary electrophoresis column with an inlet and outlet end, a means of injection, and means of applying a high voltage to cause the differential migration of species of interest through the capillary column. Effluent from the liquid chromatography column passes over the inlet end of the capillary electrophoresis column through a tee structure and when the loading of the capillary electrophoresis column is desired, a voltage supply is activated at a precise voltage and polarity over a specific duration to cause sample species to be diverted from the flowing stream to the capillary electrophoresis column. A laser induced fluorescence detector preferably is used to analyze the products separated while in the electrophoresis column.

  5. Observations of UHF oscillations in the IPNS RCS proton bunch. PROTON BUNCH

    SciTech Connect

    Dooling, J. C.; Brumwell, F. R.; McMichael, G. E.; Wang, S.; Intense Pulsed Neutron Source

    2005-01-01

    The Intense Pulsed Neutron Source (IPNS) Rapid Cycling Synchrotron (RCS) accelerates 3.2 x 10E{sup 12} protons from 50 MeV to 450 MeV in a single bunch (h=1) at 30 Hz. The rf frequency varies from 2.21 MHz to 5.14 MHz during the 14.2 ms acceleration interval. To maintain stability of the bunch, phase modulation is introduced to the rf at approximately twice the synchrotron frequency (synchrotron tune is 0.0014). This phase modulation causes a parametric quadrupole oscillation to develop in the bunch, and as this occurs, the bunch spectrum shows a significant increase in high frequency content. Without phase modulation, the beam experiences an instability which results in the loss of a large fraction of the charge 2-4 ms prior to extraction. It is unclear if the stability imparted to the beam by phase modulation comes from the quadrupole oscillation or from the high frequency excitation. A longitudinal tracking code has been modified to include amplitude and phase modulation of the bunch. The numerical analysis is used to compare growth rates with those observed in the machine. The results of this analysis will be important as we introduce second harmonic rf with a new third cavity in the RCS later in 2005.

  6. Diagnostic and numerical studies of the IPNS LINAC with a recently installed buncher amplifier.

    SciTech Connect

    Dooling, J. C.; Donley, L. I.; McMichael, G. E.; Stipp, V. F.

    2002-09-17

    The Intense Pulse Neutron Source (IPNS) 50-MeV Drift-Tube Linac uses a single-gap, single-harmonic buncher cavity to increase transmission efficiency. However, it is also the case that the linac output beam longitudinal and transverse emittance is dependent on buncher amplitude and phase as well as with the input beam energy and emittance. The linac is the injector for a Rapid Cycling Synchrotron (RCS) that increases the beam energy to 450 MeV and shortens the pulse to the 100 ns region. The RCS is operated loss-limited, and its operating current is strongly dependent on the properties (emittance, and its variation during the pulse) of the beam from the linac. A new amplifier has been installed allowing for better amplitude and phase control of buncher rf. This new amplifier gives independent control of amplitude and phase, permitting more systematic studies of the relation between linac and RCS performance. This paper presents the results of recent studies where we characterize beam properties that lead to high efficiency operation in both linac and RCS, and compare them with simulation calculations.

  7. Rapid Cycle Amine (RCA 2.0) System Development

    NASA Technical Reports Server (NTRS)

    Papale, William; O'Coin, James; Wichowski, Robert; Chullen, Cinda; Campbell, Colin

    2013-01-01

    The Rapid Cycle Amine (RCA) system is a low-power assembly capable of simultaneously removing carbon dioxide (CO2) and humidity from an influent air steam and subsequent regeneration when exposed to a vacuum source. Two solid amine sorbent beds are alternated between an uptake mode and a regeneration mode. During the uptake mode, the sorbent is exposed to an air steam (ventilation loop) to adsorb CO2 and water (H2O) vapor, whereas during the regeneration mode, the sorbent rejects the adsorbed CO2 and H2O vapor to a vacuum source. The two beds operate such that while one bed is in the uptake mode, the other is in the regeneration mode, thus continuously providing an on-service sorbent bed by which CO2 and humidity may be removed. A novel valve assembly provides a simple means of diverting the process air flow through the uptake bed while simultaneously directing the vacuum source to the regeneration bed. Additionally, the valve assembly is designed to allow for switching between uptake and regeneration modes with only one moving part while minimizing gas volume losses to the vacuum source by means of an internal pressure equalization step during actuation. The process can be controlled by a compact, low-power controller design with several modes of operation available to the user. Together with NASA Johnson Space Center, Hamilton Sundstrand Space Systems International, Inc. has been developing RCA 2.0 based on performance and design feedback on several sorbent bed test articles and valve design concepts. A final design of RCA 2.0 was selected in November 2011 and fabricated and assembled between March and August 2012, with delivery to NASA Johnson Space Center in September 2012. This paper provides an overview of the RCA system design and results of pre-delivery testing.

  8. Rapid Cycle Amine (RCA 2.0) System Development

    NASA Technical Reports Server (NTRS)

    Papale, William; O'Coin, James; Wichowski, Robert; Chullen, Cinda; Campbell, Colin

    2012-01-01

    The Rapid Cycle Amine (RCA) system is a low power assembly capable of simultaneously removing carbon dioxide (CO2) and humidity from an influent air steam and subsequent regeneration when exposed to a vacuum source. Two solid amine sorbent beds are alternated between an uptake mode and a regeneration mode. During the uptake mode, the sorbent is exposed to an air steam (ventilation loop) to adsorb CO2 and water vapor, while during the regeneration mode, the sorbent rejects the adsorbed CO2 and water vapor to a vacuum source. The two beds operate such that while one bed is in the uptake mode, the other is in the regeneration mode, thus continuously providing an on-service sorbent bed by which CO2 and humidity may be removed. A novel valve assembly provides a simple means of diverting the process air flow through the uptake bed while simultaneously directing the vacuum source to the regeneration bed. Additionally, the valve assembly is designed to allow for switching between uptake and regeneration modes with only one moving part while minimizing gas volume losses to the vacuum source by means of an internal pressure equalization step during actuation. The process can be controlled by a compact, low power controller design with several modes of operation available to the user. Together with NASA, United Technologies Corporation Aerospace Systems has been developing RCA 2.0 based on performance and design feedback on several sorbent bed test articles and valve design concepts. A final design was selected in November 2011 and fabricated and assembled between March and August 2012, with delivery to NASA-JSC in September 2012. This paper will provide an overview on the RCA system design and results of pre-delivery testing.

  9. Rapid Cycle Amine (RCA) 3.0 System Development

    NASA Technical Reports Server (NTRS)

    Chullen, Cinda; Campbell, Colin; Papale, William; Hawes, Kevin; Wichowski, Robert

    2015-01-01

    The Rapid Cycle Amine (RCA) 3.0 system is currently under development by NASA, the Lyndon B. Johnson Space Center (JSC) in conjunction with United Technologies Corporation Aerospace Systems (UTAS). The RCA technology is a new carbon dioxide (CO2) and humidity removal system that has been baselined for the Advanced Extravehicular Mobility Unit (AEMU) Portable Life Support System. The evolution of the RCA development has progressed through several iterations of technology readiness levels including RCA 1.0, RCA 2.0, and RCA 3.0 test articles. The RCA is an advancement over currently technologies due to its unique regeneration capability. The RCA is capable of simultaneously removing CO2 and humidity from an influent air steam and subsequent regeneration when exposed to a vacuum source. The RCA technology uses two solid amine sorbent beds in an alternating fashion to adsorb CO2 and water (uptake mode) and desorb CO2 and water (regeneration mode) at the same time. The two beds operate in an efficient manner so that while one bed is in the uptake mode, the other is in the regeneration mode, thus continuously providing an on-service sorbent bed by which CO2 and humidity may be removed. The RCA 2.0 and 3.0 test articles were designed with a novel valve assembly which allows for switching between uptake and regeneration modes with only one moving part while minimizing gas volume losses to the vacuum source by means of an internal pressure equalization step during actuation. The RCA technology also is low power, small, and has performed extremely well in all development testing thus far. A final design was selected for the RCA 3.0, fabricated, assembled, and performance tested in 2014 with delivery to NASAJSC in January 2015. This paper will provide an overview on the RCA 3.0 system design and results of pre-delivery testing with references to the development of RCA 1.0 and RCA 2.0.

  10. Vagus Nerve Stimulation Applied with a Rapid Cycle Has More Profound Influence on Hippocampal Electrophysiology Than a Standard Cycle.

    PubMed

    Larsen, Lars E; Wadman, Wytse J; Marinazzo, Daniele; van Mierlo, Pieter; Delbeke, Jean; Daelemans, Sofie; Sprengers, Mathieu; Thyrion, Lisa; Van Lysebettens, Wouter; Carrette, Evelien; Boon, Paul; Vonck, Kristl; Raedt, Robrecht

    2016-07-01

    Although vagus nerve stimulation (VNS) is widely used, therapeutic mechanisms and optimal stimulation parameters remain elusive. In the present study, we investigated the effect of VNS on hippocampal field activity and compared the efficiency of different VNS paradigms. Hippocampal electroencephalography (EEG) and perforant path dentate field-evoked potentials were acquired before and during VNS in freely moving rats, using 2 VNS duty cycles: a rapid cycle (7 s on, 18 s off) and standard cycle (30 s on, 300 s off) and various output currents. VNS modulated the evoked potentials, reduced total power of the hippocampal EEG, and slowed the theta rhythm. In the hippocampal EEG, theta (4-8 Hz) and high gamma (75-150 Hz) activity displayed strong phase amplitude coupling that was reduced by VNS. Rapid-cycle VNS had a greater effect than standard-cycle VNS on all outcome measures. Using rapid cycle VNS, a maximal effect on EEG parameters was found at 300 μA, beyond which effects saturated. The findings suggest that rapid-cycle VNS produces a more robust outcome than standard cycle VNS and support already existing preclinical evidence that relatively low output currents are sufficient to produce changes in brain physiology and thus likely also therapeutic efficacy. PMID:27102987

  11. Plant Growth and Development: An Outline for a Unit Structured Around the Life Cycle of Rapid-Cycling Brassica Rapa.

    ERIC Educational Resources Information Center

    Becker, Wayne M.

    This outline is intended for use in a unit of 10-12 lectures on plant growth and development at the introductory undergraduate level as part of a course on organismal biology. The series of lecture outlines is structured around the life cycle of rapid-cycling Brassica rapa (RCBr). The unit begins with three introductory lectures on general plant…

  12. Rapid-fire improvement with short-cycle kaizen.

    PubMed

    Heard, E

    1999-05-01

    Continuous improvement is an attractive idea, but it is typically more myth than reality. SCK is no myth. It delivers dramatic improvements in traditional measures quickly. SCK accomplishes this via kaizens: rapid, repeated, time-compressed changes for the better in bite-sized chunks of the business. PMID:10387776

  13. Plasma considerations in the IPNS RCS.

    SciTech Connect

    Dooling, J. C.; McMichael, G. E.; Brumwell, F. R.

    2002-02-21

    Significant ionization appears to occur in the Rapid Cycling Synchrotron (RCS) during its 14 ms acceleration period leading to plasma formation and neutralization. The beam may in fact be over-neutralized, causing the tune to increase during the acceleration cycle. The overall tune shift in the RCS appears to be close to +0.5. The presence of plasma may help explain why longitudinal phase modulation can so quickly couple to transverse motion. In addition, plasmas tend to be inductive and the RCS appears to exhibit a relatively high inductance. Measurements of the electron cloud and plasma densities adjacent to the beam should be made. In addition to the RFA and Swept Analyzer diagnostics mentioned at the Workshop, other techniques might be attempted. If plasma is present, then a small, biased-probe might be useful (e.g., a Langmuir probe), or with the proper choice of geometry, an optics-based measurement for line density (e.g., an interferometer) might be employed, perhaps using microwaves for increased sensitivity.

  14. The Hydrologic Cycle Response to Rapid Arctic Vegetation Change

    NASA Astrophysics Data System (ADS)

    Snyder, P. K.

    2008-12-01

    Over the last fifty years, the Northern Hemisphere high latitude land areas have warmed at rates well in excess of what can be explained by the atmospheric rise in greenhouse gases alone. Changes in the albedo of the ocean and land, whether from the loss of Arctic Ocean sea ice, changes in land cover, or changes in winter precipitation patterns account for much of the amplified warming. Although the loss of sea ice is directly related to greenhouse gas warming and low-level winds, changes in the discharge of freshwater from Arctic river basins are also responsible. While changes in river discharge can be related to precipitation, snow and ice melt, and human modification of the landscape, natural vegetation changes due to warming may also be altering the land surface hydrologic cycle and contributing to changes in the flux of freshwater to the Arctic Ocean. Satellite imagery has shown that the Arctic is becoming greener, which not only affects the surface and lower-tropospheric energy budget, but also modifies the hydrologic cycle through altering the partitioning of transpiration and plant-soil evaporation. This leads to changes in precipitation recycling and runoff, which can ultimately affect the discharge of freshwater. To illustrate this mechanism, results of a land cover change and precipitation-recycling analysis using North American Regional Reanalysis data will be presented for the Mackenzie Basin in North America. Additionally, results from a dynamic global vegetation model will be presented to evaluate the potential consequences of continued extreme warming and land cover changes to the discharge of freshwater to the Arctic Ocean.

  15. Tropical Cyclone Structure Change Cycles during Rapid Intensification

    NASA Astrophysics Data System (ADS)

    Nguyen, Chi Mai; Reeder, Michael J.; Davidson, Noel E.; Smith, Roger K.; Montgomery, Michael T.

    2010-05-01

    High-resolution simulations of Hurricane Katrina (2005) using TCLAPS show that the modelled vortex vacillates between symmetric and asymmetric phases during periods of rapid intensification. During the Symmetric phase the eye-wall has a high degree of symmetry, comprising relatively uniform elongated convective bands. In this phase the low-level vorticity and equivalent potential temperature fields exhibit a ring-like structure, and the largest intensification rates occur near the radius of maximum tangential wind (RMW). In contrast, the Asymmetric phase is characterised by a highly asymmetric eyewall, having a polygonal form with vortical hot towers (VHTs) located at the vertices. The low-level vorticity and equivalent potential temperature fields have monopole structures with their maxima near the center. In this phase, the largest intensification rates occur inside the RMW. These two phases are very similar to Regimes 1 and 2 respectively found by Kossin and Eastin (2001) using aircraft observations. Symmetric to Asymmetric transitions are associated with the development of VHTs along the eyewall, resulting from a combination of barotropic and convective instability. These VHTs vigorously mix the air between the eye and eyewall, increasing the vorticity near the vortex center. In conrast, Asymmetric to Symmetric transitions occur as the potential energy available to the convection is consumed and the VHTs weaken. In the process the VHTs become strained in the horizontal and move radially outward as vortex Rossby waves (VRWs). High intensification rates resume near the RMW as result of increased horizontal vorticity fluxes associated with redevelopment of convection in the reduced rapid filamentation zone outside of the weakened VHTs, and through VRW wave-mean flow interactions.

  16. Rapid cycling of reactive nitrogen in the marine boundary layer.

    PubMed

    Ye, Chunxiang; Zhou, Xianliang; Pu, Dennis; Stutz, Jochen; Festa, James; Spolaor, Max; Tsai, Catalina; Cantrell, Christopher; Mauldin, Roy L; Campos, Teresa; Weinheimer, Andrew; Hornbrook, Rebecca S; Apel, Eric C; Guenther, Alex; Kaser, Lisa; Yuan, Bin; Karl, Thomas; Haggerty, Julie; Hall, Samuel; Ullmann, Kirk; Smith, James N; Ortega, John; Knote, Christoph

    2016-04-28

    Nitrogen oxides are essential for the formation of secondary atmospheric aerosols and of atmospheric oxidants such as ozone and the hydroxyl radical, which controls the self-cleansing capacity of the atmosphere. Nitric acid, a major oxidation product of nitrogen oxides, has traditionally been considered to be a permanent sink of nitrogen oxides. However, model studies predict higher ratios of nitric acid to nitrogen oxides in the troposphere than are observed. A 'renoxification' process that recycles nitric acid into nitrogen oxides has been proposed to reconcile observations with model studies, but the mechanisms responsible for this process remain uncertain. Here we present data from an aircraft measurement campaign over the North Atlantic Ocean and find evidence for rapid recycling of nitric acid to nitrous acid and nitrogen oxides in the clean marine boundary layer via particulate nitrate photolysis. Laboratory experiments further demonstrate the photolysis of particulate nitrate collected on filters at a rate more than two orders of magnitude greater than that of gaseous nitric acid, with nitrous acid as the main product. Box model calculations based on the Master Chemical Mechanism suggest that particulate nitrate photolysis mainly sustains the observed levels of nitrous acid and nitrogen oxides at midday under typical marine boundary layer conditions. Given that oceans account for more than 70 per cent of Earth's surface, we propose that particulate nitrate photolysis could be a substantial tropospheric nitrogen oxide source. Recycling of nitrogen oxides in remote oceanic regions with minimal direct nitrogen oxide emissions could increase the formation of tropospheric oxidants and secondary atmospheric aerosols on a global scale. PMID:27064904

  17. Rapid cycling of reactive nitrogen in the marine boundary layer

    NASA Astrophysics Data System (ADS)

    Ye, Chunxiang; Zhou, Xianliang; Pu, Dennis; Stutz, Jochen; Festa, James; Spolaor, Max; Tsai, Catalina; Cantrell, Christopher; Mauldin, Roy L.; Campos, Teresa; Weinheimer, Andrew; Hornbrook, Rebecca S.; Apel, Eric C.; Guenther, Alex; Kaser, Lisa; Yuan, Bin; Karl, Thomas; Haggerty, Julie; Hall, Samuel; Ullmann, Kirk; Smith, James N.; Ortega, John; Knote, Christoph

    2016-04-01

    Nitrogen oxides are essential for the formation of secondary atmospheric aerosols and of atmospheric oxidants such as ozone and the hydroxyl radical, which controls the self-cleansing capacity of the atmosphere. Nitric acid, a major oxidation product of nitrogen oxides, has traditionally been considered to be a permanent sink of nitrogen oxides. However, model studies predict higher ratios of nitric acid to nitrogen oxides in the troposphere than are observed. A ‘renoxification’ process that recycles nitric acid into nitrogen oxides has been proposed to reconcile observations with model studies, but the mechanisms responsible for this process remain uncertain. Here we present data from an aircraft measurement campaign over the North Atlantic Ocean and find evidence for rapid recycling of nitric acid to nitrous acid and nitrogen oxides in the clean marine boundary layer via particulate nitrate photolysis. Laboratory experiments further demonstrate the photolysis of particulate nitrate collected on filters at a rate more than two orders of magnitude greater than that of gaseous nitric acid, with nitrous acid as the main product. Box model calculations based on the Master Chemical Mechanism suggest that particulate nitrate photolysis mainly sustains the observed levels of nitrous acid and nitrogen oxides at midday under typical marine boundary layer conditions. Given that oceans account for more than 70 per cent of Earth’s surface, we propose that particulate nitrate photolysis could be a substantial tropospheric nitrogen oxide source. Recycling of nitrogen oxides in remote oceanic regions with minimal direct nitrogen oxide emissions could increase the formation of tropospheric oxidants and secondary atmospheric aerosols on a global scale.

  18. Anxiety Disorders and Rapid Cycling Data From a Cohort of 8129 Youths With Bipolar Disorder

    PubMed Central

    Castilla-Puentes, Ruby; Sala, Regina; Ng, Bernardo; Galvez, Juan; Camacho, Alvaro

    2014-01-01

    Anxiety disorders (ADs) are common in youths with bipolar disorder (BD). We examine psychiatric comorbidity, hospitalization, and treatment in youths with versus without AD and rapid cycling (four or more cycles per year). Data from the Integrated Healthcare Information Services cohort were used and included 8129 youths (ages ≤18 years). Prevalence of AD, demographic, type of AD, hospitalization, and use of psychotropics were compared between rapid and nonrapid cycling. Overall, 51% of the youths met criteria for at least one comorbid AD; they were predominantly female and were between 12 and 17 years of age. The most common comorbid ADs were generalized ADs and separation ADs. In the patients with rapid cycling, 65.5%met criteria for comorbid AD. The BD youths with AD were more likely to have major depressive disorders and other comorbid ADs, to be given more psychotropics, and to be hospitalized for depression and medical conditions more often than were those without AD. PMID:24284641

  19. Subduction cycling of U, Th, and Pb [rapid communication

    NASA Astrophysics Data System (ADS)

    Kelley, Katherine A.; Plank, Terry; Farr, Linda; Ludden, John; Staudigel, Hubert

    2005-06-01

    lost to the back-arc. Pb is lost shallow and U deep from subducted AOC, which may be a consequence of the stability of phases binding these elements during seafloor alteration: U in carbonate and Pb in sulfides. The upper end of these recycling estimates, which reflect maximum arc and back-arc growth rates, remove enough Pb and U from the slab to enable it to evolve rapidly (≪ 0.5 Ga) to sources suitable to explain the 208Pb/ 206Pb isotopic array of OIB, although these conditions fail to simultaneously satisfy the 207Pb/ 206Pb system. Lower growth rates would require additional U loss (29%) at depths beyond the zones of arc and back-arc magmagenesis, which would decrease upper mantle κ ( 232Th/ 238U) over time, consistent with one solution to the "kappa conundrum" [5] [T. Elliott, A. Zindler, B. Bourdon, Exploring the kappa conundrum: the role of recycling in the lead isotope evolution of the mantle. Earth Planet. Sci. Lett. 169 (1999) 129-145]. The net effects of alteration (doubling of μ [ 238U/ 204Pb]) and subduction (doubling of ω [ 232Th/ 204Pb]) are sufficient to create the Pb isotopic signatures of oceanic basalts.

  20. Rapid thermal cycling of metal-supported solid oxide fuel cellmembranes

    SciTech Connect

    Matus, Yuriy B.; De Jonghe, Lutgard C.; Jacobson, Craig P.; Visco, Steven J.

    2004-01-02

    Solid oxide fuel cell (SOFC) membranes were developed in which zirconia-based electrolyte thin films were supported by a composite metal/ceramic electrode, and were subjected to rapid thermal cycling between 200 and 800 C. The effects of this cycling on membrane performance were evaluated. The membranes, not yet optimized for performance, showed a peak power density of 350mW/cm2at 900 C in laboratory-sized SOFCs that was not affected by the thermal cycling. This resistance to cycling degradation is attributed to the close matching of thermal expansion coefficient of the cermet support electrode with that of the zirconia electrolyte.

  1. Rapid thermal cycling of solar array blanket coupons for Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Scheiman, David A.; Smith, Bryan K.

    1991-01-01

    The NASA Lewis Research Center has been conducting rapid thermal cycling on blanket coupons for Space Station Freedom. This testing includes two designs (8 coupons total) of the solar array. Four coupons were fabricated as part of the Photovoltaic Array Environmental Protection Program (PAEP), NAS3-25079, at Lockheed Missiles and Space Company. These coupons began cycling in early 1989 and have completed 172,000 thermal cycles. Four other coupons were fabricated a year later and included several design changes; cycling of these began in early 1990 and has reached 90,000 cycles. The objective of this testing is to demonstrate the durability or operational lifetime (15 yrs.) of the welded interconnects within a low earth orbit (LEO) thermal cycling environment. The blanket coupons, design changes, test description, status to date including performance and observed anomalies, and any insights related to the testing of these coupons are described. The description of a third design is included.

  2. Thermal Behavior of Small Lithium-Ion Secondary Battery during Rapid Charge and Discharge Cycles

    NASA Astrophysics Data System (ADS)

    Ohshima, Takamasa; Nakayama, Masato; Fukuda, Kenichi; Araki, Takuto; Onda, Kazuo

    The secondary batteries for the electric vehicle (EV) generate much heat during rapid charge and discharge cycles than the rated condition, when EV starts quickly consuming the battery power and stops suddenly recovering the inertia energy. During rapid charge and discharge cycles, the cell temperature rises significantly and may increase more than the allowable temperature. So we calculated the temperature rise of a small lithium-ion secondary battery during rapid charge and discharge cycles using our battery thermal behavior model, which we have developed being confirmed its validity during discharge cycle at the smaller current than the discharge rate of 1C. The heat source factors were measured by the methods described in our previous study, because the present batteries have been improved in their performance and have low overpotential resistance. The battery heat capacity was measured by a twin-type heat conduction calorimeter, and determined to be a linear function of temperature. Further, the heat transfer coefficient was measured again precisely by the method described in our previous study, and was arranged as a function of cell and ambient temperatures. The calculated temperature by our battery thermal behavior model using these measured data agrees well with the cell temperature measured by thermocouple. Therefore we can confirm the validity of this model again during rapid charge and discharge cycles.

  3. Rapid subtropical North Atlantic salinity oscillations across Dansgaard-Oeschger cycles.

    PubMed

    Schmidt, Matthew W; Vautravers, Maryline J; Spero, Howard J

    2006-10-01

    Geochemical and sedimentological evidence suggest that the rapid climate warming oscillations of the last ice age, the Dansgaard-Oeschger cycles, were coupled to fluctuations in North Atlantic meridional overturning circulation through its regulation of poleward heat flux. The balance between cold meltwater from the north and warm, salty subtropical gyre waters from the south influenced the strength and location of North Atlantic overturning circulation during this period of highly variable climate. Here we investigate how rapid reorganizations of the ocean-atmosphere system across these cycles are linked to salinity changes in the subtropical North Atlantic gyre. We combine Mg/Ca palaeothermometry and oxygen isotope ratio measurements on planktonic foraminifera across four Dansgaard-Oeschger cycles (spanning 45.9-59.2 kyr ago) to generate a seawater salinity proxy record from a subtropical gyre deep-sea sediment core. We show that North Atlantic gyre surface salinities oscillated rapidly between saltier stadial conditions and fresher interstadials, covarying with inferred shifts in the Tropical Atlantic hydrologic cycle and North Atlantic overturning circulation. These salinity oscillations suggest a reduction in precipitation into the North Atlantic and/or reduced export of deep salty thermohaline waters during stadials. We hypothesize that increased stadial salinities preconditioned the North Atlantic Ocean for a rapid return to deep overturning circulation and high-latitude warming by contributing to increased North Atlantic surface-water density on interstadial transitions. PMID:17024090

  4. Methods for separation/purification utilizing rapidly cycled thermal swing sorption

    DOEpatents

    Tonkovich, Anna Lee Y.; Monzyk, Bruce F.; Wang, Yong; VanderWiel, David P.; Perry, Steven T.; Fitzgerald, Sean P.; Simmons, Wayne W.; McDaniel, Jeffrey S.; Weller, Jr., Albert E.

    2004-11-09

    The present invention provides apparatus and methods for separating fluid components. In preferred embodiments, the apparatus and methods utilize microchannel devices with small distances for heat and mass transfer to achieve rapid cycle times and surprisingly large volumes of fluid components separated in short times using relatively compact hardware.

  5. Computer, Video, and Rapid-Cycling Plant Projects in an Undergraduate Plant Breeding Course.

    ERIC Educational Resources Information Center

    Michaels, T. E.

    1993-01-01

    Studies the perceived effectiveness of four student projects involving videotape production, computer conferencing, microcomputer simulation, and rapid-cycling Brassica breeding for undergraduate plant breeding students in two course offerings in consecutive years. Linking of the computer conferencing and video projects improved the rating of the…

  6. Demonstrated Ways to Use Rapid Cycling "Brassica Rapa" in Ecology Instruction and Research

    ERIC Educational Resources Information Center

    Kelly, Martin G.

    2004-01-01

    The National Science Foundation has a long supported the use of "Wisconsin Fast Plants" (rapid cycling "B. rapa") in the teaching of Biology (K-12). I believe that the opportunity is at hand for biologists to significantly extend past efforts made by our colleagues at the K-12 level to higher education. Biology faculty can realize the many…

  7. Thermal behavior of small lithium-ion battery during rapid charge and discharge cycles

    NASA Astrophysics Data System (ADS)

    Onda, Kazuo; Ohshima, Takamasa; Nakayama, Masato; Fukuda, Kenichi; Araki, Takuto

    The secondary batteries for electric vehicles (EV) generate much heat during rapid charge and discharge cycles at current levels exceeding the batteries' rating, such as when the EV quickly starts consuming battery power or when recovering inertia energy during sudden stops. During these rapid charge and discharge cycles, the cell temperature may increase above allowable limits. We calculated the temperature rise of a small lithium-ion secondary battery during rapid charge and discharge cycles. The heat-source factors were measured again by the methods described in our previous study, because the performance of the battery reported here has been improved, showing lower overpotential resistance. Battery heat capacity was measured by a twin-type heat conduction calorimeter, and determined to be a linear function of temperature. Further, the heat transfer coefficient, measured again precisely by the method described in our previous study, was arranged as a function of cell and ambient temperatures. The temperature calculated by our battery thermal behavior model using these measured data agrees well with the cell temperature measured by thermocouple during rapid charge and discharge cycles. Also, battery radial temperature distributions were calculated to be small, and confirmed experimentally.

  8. Superporous polyacrylate/chitosan IPN hydrogels for protein delivery.

    PubMed

    Gümüşderelioğlu, Menemşe; Erce, Deniz; Demirtaş, T Tolga

    2011-11-01

    In this study, poly(acrylamide), poly(AAm), and poly(acrylamide-co-acrylic acid), poly(AAm-co-AA) superporous hydrogels (SPHs) were synthesized by radical polymerization in the presence of gas blowing agent, sodium bicarbonate. In addition, ionically crosslinked chitosan (CH) superporous hydrogels were synthesized to form interpenetrating superporous hydrogels, i.e. poly(AAm)-CH and poly(AAm-co-AA)-CH SPH-IPNs. The hydrogels have a structure of interconnected pores with pore sizes of approximately 100-150 μm. Although the extent of swelling increased when AA were incorporated to the poly(AAm) structure, the time to reach the equilibrium swelling (~30 s) was not affected so much. In the presence of chitosan network mechanical properties significantly improved when compared with SPHs, however, equilibrium swelling time (~30 min) was prolonged significantly as due to the lower porosities and pore sizes of SPH-IPNs than that of SPHs. Model protein bovine serum albumin (BSA) was loaded into SPHs and SPH-IPNs by solvent sorption in very short time (<1 h) and very high capacities (~30-300 mg BSA/g dry gel) when compared to conventional hydrogels. BSA release profiles from SPHs and SPH-IPNs were characterized by an initial burst of protein during the first 20 min followed by a completed release within 1 h. However, total releasable amount of BSA from SPH-IPNs was lower than that of SPHs as due to the electrostatic interactions between chitosan and BSA. PMID:21901372

  9. Degradation of Teflon(trademark) FEP Following Charged Particle Radiation and Rapid Thermal Cycling

    NASA Technical Reports Server (NTRS)

    Townsend, Jacqueline; Powers, Charles; Viens, Michael; Ayres-Treusdell, Mary; Munoz, Bruno

    1999-01-01

    During the Second Servicing Mission (SM2) of the Hubble Space Telescope (HST) severe degradation was observed on the outer layer of the thermal control blankets. Astronaut observations and photographs revealed large cracks in the metallized Teflon(trademark) FEP (fluorinated ethylene propylene), the outer layer of the multi-layer insulation (MLI), in many locations around the telescope. In an effort to understand what elements of the space environment might cause such damage, pristine Teflon(trademark) FEP was tested for durability to radiation and thermal cycling. Specimens were subjected to electron and proton fluences comparable to those experienced by HST and were subsequently thermal cycled in a custom-built rapid thermal cycle chamber. Tensile tests of the specimens showed that radiation followed by thermal cycling significantly reduced the ultimate strength and elongation of Teflon(trademark) FEP.

  10. Degradation of Teflon(tm) FEP Following Charged Particle Radiation and Rapid Thermal Cycling

    NASA Technical Reports Server (NTRS)

    Townsend, Jacqueline A.; Powers, Charles E.; Viens, Michael J.; Ayres-Treusdell, Mary T.; Munoz, Bruno

    1998-01-01

    During the Second Servicing Mission (SM2) of the Hubble Space Telescope (HST) severe degradation was observed on the outer layer of the thermal control blankets. Astronaut observations and photographs revealed large cracks in the metallized Teflon FEP (fluorinated ethylene propylene), the outer layer of the multi-layer insulation (MLI), in many locations around the telescope. In an effort to understand what elements of the space environment might cause such damage, pristine Teflon' FEP was tested for durability to radiation and thermal cycling. Specimens were subjected to electron and proton fluences comparable to those experienced by HST and were subsequently thermal cycled in a custom-built rapid thermal cycle chamber. Tensile tests of the specimens showed that radiation followed by thermal cycling significantly reduced the ultimate strength and elongation of Teflon FEP.

  11. Degradation of Teflon(tm) FEP Following Charged Particle Radiation and Rapid Thermal Cycling

    NASA Technical Reports Server (NTRS)

    Townsend, Jacqueline A.; Powers, Charles E.; Viens, Michael J.; Ayres-Treusdell, Mary T.; Munoz, Bruno F.

    1998-01-01

    During the Second Servicing Mission (SM2) of the Hubble Space Telescope (HST) severe degradation was observed on the outer layer of the thermal control blankets. Astronaut observations and photographs revealed large cracks in the metallized Teflon' FEP (fluorinated ethylene propylene), the outer layer of the multi-layer insulation (MLI), in many locations around the telescope. In an effort to understand what elements of the space environment might cause such damage, pristine Teflon(registered trademark) FEP was tested for durability to radiation and thermal cycling. Specimens were subjected to electron and proton fluences comparable to those experienced by HST and were subsequently thermal cycled in a custom-built rapid thermal cycle chamber. Tensile tests of the specimens showed that radiation followed by thermal cycling significantly reduced the ultimate strength and elongation of Teflon(registered trademark) FEP.

  12. Degradation of Teflon(tm) FEP Following Charged Particle Radiation and Rapid Thermal Cycling

    NASA Technical Reports Server (NTRS)

    Townsend, Jacqueline; Powers, Charles; Viens, Michael; Ayres-Treusdell, Mary; Munoz, Bruno

    1998-01-01

    During the Second Servicing Mission (SM2) of the Hubble Space Telescope (HST) severe degradation was observed on the outer layer of the thermal control blankets. Astronaut observations and photographs revealed large cracks in the metallized Teflon(R) FEP (fluorinated ethylene propylene), the outer layer of the multi-layer insulation (MLI), in many locations around the telescope. In an effort to understand what elements of the space environment might cause such damage, pristine Teflon(R) FEP was tested for durability to radiation and thermal cycling. Specimens were subjected to electron and proton fluences comparable to those experienced by HST and were subsequently thermal cycled in a custom-built rapid thermal cycle chamber. Tensile tests of the specimens showed that radiation followed by thermal cycling significantly reduced the ultimate strength and elongation of Teflon(R) FEP.

  13. Thermally cured semi-interpenetrating electrolyte networks (s-IPN) for safe and aging-resistant secondary lithium polymer batteries

    NASA Astrophysics Data System (ADS)

    Nair, Jijeesh R.; Destro, Matteo; Bella, Federico; Appetecchi, Giovanni B.; Gerbaldi, Claudio

    2016-02-01

    Truly solid polymer electrolyte membranes are designed by thermally induced free radical polymerisation. The overall membrane architecture is built on a semi-interpenetrating polymer network (s-IPN) structure, where a di-methacrylate oligomer is cross-linked (in situ) in the presence of a long thermoplastic linear PEO chain and a supporting lithium salt to obtain a freestanding, flexible and non-tacky film. In the envisaged systems, the di-methacrylate functions as a soft cross-linker, thus avoiding physico-mechanical deformation of the s-IPNs at elevated temperature, without hampering the ionic conductivity. s-IPNs exhibit remarkable stability towards lithium metal and no traces of impurity are detected while testing their oxidation stability (4.7 V vs. Li/Li+) towards anodic potential. The newly elaborated system is also successfully tested at moderately high temperature in Li metal cells in which LiFePO4/C is used as the cathode active material, showing excellent indications of safe and highly durable electrolyte separator (i.e., 2000 cycles at reasonably high 1C rate).

  14. A novel pH-sensitive membrane from chitosan--TEOS IPN; preparation and its drug permeation characteristics.

    PubMed

    Park, S B; You, J O; Park, H Y; Haam, S J; Kim, W S

    2001-02-01

    A novel organic-inorganic composite membrane was prepared, using tetra ethyl ortho silicate (TEOS) as an inorganic material and chitosan as an organic compound. Equilibrium and oscillatory swelling studies were conducted to investigate swelling behaviors of the membrane according to the pH of the swelling medium. Drug permeation experiments were also performed in phosphate buffer solution of the pH of 2.5 and 7.5, respectively. Lidocaine HCl, sodium salicylate and 4-acetamidophenol were selected as model drugs to examine the effect of ionic property of drug on the permeation behavior. The effects of membrane composition and the external pH on the swelling and the drug permeation behavior of IPN membrane could be summarized as follows; chitosan incorporated into TEOS IPN swelled at pH 2.5 while shrunk at pH 7.5. This swelling behavior was completely reversible and the membrane responded rapidly to the change in environmental pH condition. According to swelling behavior, an increase in pH from 2.5 to 7.5 yielded an increase in the rate of drug permeation because of the shrinking of the incorporated chitosan in TEOS IPN, while decrease in pH resulted in low permeation rate. The optimal TEOS-chitosan ratio for maximum pH-sensitivity existed and drug permeation was influenced not only with the external pH but also with the ionic interactions between the drug and membrane. PMID:11205435

  15. Thermal Behavior of Prismatic Lithium-Ion Battery during Rapid Charge and Discharge Cycles

    NASA Astrophysics Data System (ADS)

    Araki, Takuto; Wakahara, Kenji; Fukuda, Kenichi; Ohmori, Yositake; Nakayama, Masato; Onda, Kazuo

    The temperature of secondary batteries may increase above allowable limits and deteriorate its performance, during rapid charge and discharge cycles. Therefore, assessing thermal behavior of battery is essential. On the other hand, rectangular parallelepiped shape batteries are supposedly going to be used more commonly for cars and electrical devices because of their better space efficiency. Then, we constructed a two dimensional Cartesian coordinates battery thermal behavior model for a prismatic lithium-ion secondary battery during rapid charge and discharge cycles. It was extended from one dimensional cylindrical coordinates model, which had been developed and experimentally verified. As parameters of the numerical model, battery heat source factors such as overpotential resistance, entropy change, heat transfer coefficient and heat capacity have been measured. The radiation thermometer was used for obtaining battery surface temperature variance and distributions. Battery temperature generally increases as charge and discharge cycle proceeds, nevertheless temperature drops were observed at begging of low rate charge cycle and vicinity of SOC=0.8 in discharge cycle. Our modified model could predict these phenomena and agreed well with experimental results. Then the reliability of our numerical model and measuring techniques of heat source factors are confirmed each other.

  16. Mechanically tough biomacromolecular IPN hydrogel fibers by enzymatic and ionic crosslinking.

    PubMed

    Hu, Xin; Lu, Lingling; Xu, Chen; Li, Xinsong

    2015-01-01

    In this report, biological macromolecular full IPN hydrogel fibers composed of gelatin and alginate with an interpenetrating network (IPN) structure were prepared by wet spinning using a combination of enzymatic and calcium ions crosslinking. In the full IPN hydrogel fibers, mTG catalyzed the formation of one network of gelatin while calcium ions crosslinked another network of alginate intertwining with the former. The mechanical strength of the full IPN hydrogel fibers was measured by an electronic single fiber strength tester. The results showed that gelatin-alginate full IPN hydrogel fibers had a significant improvement of mechanical strength over gelatin-alginate semi-IPN gel fibers crosslinked only by calcium ions. The full IPN fiber has the highest tension of 62 cN and elongation of 739%, which are much higher than those of alginate hydrogel. Furthermore, biological evaluation indicated that gelatin-alginate full IPN hydrogel fibers enhance cell adhesion and proliferation significantly, illustrating the cyto-compatibility. A preliminary trial of hand weaving showed the knittability of the mechanically tough full IPN hydrogel fibers. Because of their both excellent biocompatibility and mechanical strength, the biological macromolecular hydrogel fibers with full IPN structure may be desirable candidates for engineering tissue scaffolds. PMID:25193098

  17. Dose assessment of an accidental exposure at IPNS

    SciTech Connect

    Torres, M.M.C.

    1996-05-01

    Seven different methods were used to estimate the dose rate to a female worker who was accidentally exposed in the neutron PHOENIX beamline at the IPNS. Theoretical and measured entrance dose rates ranged from 550 mrem/min to 2,850 mrem/min. Theoretical estimates were based on a Monte Carlo simulation of a spectrum provided by IPNS (Crawford Spectrum). Dose measurements were made with TLDs on phantoms and with ionization chambers in a water phantom. Estimates of the whole body total effective dose equivalent (TEDE) rate ranged from 5.2 mrem/min to 840 mrem/min. Assumed and measured quality factors ranged from 2.6 to 11.8. Cytogenic analyses of blood samples detected no positive exposure. The recommended TEDE rate was 158 mrem/min. The TEDE was 750 mrem.

  18. Dose assessment of an accidental exposure at the IPNS

    SciTech Connect

    Campos Torres, M.M.

    1995-02-01

    Seven different methods were used to estimate the dose rate to a female worker who was accidentally exposed in the neutron PHOENIX beamline at the IPNS. Theoretical and measured entrance dose ranged from 550 mrem/min to 2850 mrem/min. Theoretical estimates were based on a Monte Carlo simulation of a spectrum provided by IPNS (Crawford Spectrum). Dose measurements were made with TLDs on phantoms and with ionization chambers in a water phantom. Estimates of the whole body total effective dose equivalent (TEDE) rate ranged from 5.2 mrem/min to 840 mrem/min. Assumed and measured quality factors ranged from 2.6 to 11.8. Cytogenetic analyses of blood samples detected no positive exposure. The recommended TEDE rate was 158 mrem/min. The TEDE was 750 mrem.

  19. Thermal Behavior of Nickel-Metal Hydride Battery during Rapid Charge and Discharge Cycles

    NASA Astrophysics Data System (ADS)

    Nakayama, Masato; Fukuda, Kenichi; Araki, Takuto; Onda, Kazuo

    The secondary batteries for the electric vehicle (EV) generate much heat during rapid charge and discharge cycles, when the EV starts quickly consuming the battery power and stops suddenly recovering the inertia energy. The generated heat increases significantly the cell temperature and causes possibly bad influences on the battery performance and the safely requirement. So we have studied the thermal behavior of nickel/metal hydride (Ni/MH) battery during rapid charge and discharge cycles, applying our previous battery thermal model, which have been confirmed to agree with the experimental results at smaller charge current than the rated current. The heat sources by the entropy change, the hydrogen occlusion and the side reaction have been referred to the published data, and the overpotential resistance and the current efficiency, the ratio of main reaction current to charge current, have been measured experimentally through the rapid charge and discharge characteristics with constant current. By using these data our thermal model for Ni/MH battery has estimated its temperature increase, which agrees well with the measured temperature rise, with the root mean square error of 1.5°C and 2.1°C for charge and discharge cycles, respectively.

  20. New instruments at IPNS: POSY II and SAD II

    SciTech Connect

    Crawford, R.K.; Felcher, G.P.; Kleb, R.; Epperson, J.E.; Thiyagarajan, P.

    1988-09-29

    Three new instruments are currently in varying degrees of development/construction at IPNS. One of these, the Glass, Liquid, and Amorphous Materials Diffractometer (GLAD) is the subject of a separate paper in these Proceedings, and so will not be discussed further here. The other two, a second neutron reflectometer (POSY II) and a second small-angle diffractometer (SAD II) are described briefly below. 5 refs., 1 fig., 1 tab.

  1. Design Challenges of a Rapid Cycling Synchrotron for Carbon/Proton Therapy

    NASA Astrophysics Data System (ADS)

    Cook, Nathan

    2012-03-01

    The growing interest in radiation therapy with protons and light ions has driven demand for new methods of ion acceleration and the delivery of ion beams. One exciting new platform for ion beam acceleration and delivery is the rapid cycling synchrotron. Operating at 15Hz, rapid cycling achieves faster treatment times by making beam extraction possible at any energy during the cycle. Moreover, risk to the patient is reduced by requiring fewer particles in the beam line at a given time, thus eliminating the need for passive filtering and reducing the consequences of a malfunction. Lastly, the ability to switch between carbon ion and proton beam therapy provides the machine with an unmatched flexibility. However, these features do stipulate challenges in accelerator design. Maintaining a compact lattice requires careful tuning of lattice functions, tight focusing combined function magnets, and fast injection and extraction systems. Providing the necessary acceleration over a short cycle time also necessitates a five-fold frequency swing for carbon ions, further burdening the design requirements of ferrite-driven radiofrequency cavities. We will consider these challenges as well as some solutions selected for our current design.

  2. Conducting IPN actuator/sensor for biomimetic vibrissa system

    NASA Astrophysics Data System (ADS)

    Festin, N.; Plesse, C.; Pirim, P.; Chevrot, C.; Vidal, F.

    2014-03-01

    Electroactive polymers, or EAPs, are polymers that exhibit a change in size or shape when stimulated by an electric field. The most common applications of this type of material are in actuators and sensors. One promising technology is the elaboration of electronic conducting polymers based actuators with Interpenetrating Polymer Networks (IPNs) architecture. Their many advantageous properties as low working voltage, light weight and high lifetime make them very attractive for various applications including robotics. Conducting IPNs were fabricated by oxidative polymerization of 3,4-ethylenedioxythiophene within a flexible Solid Polymer Electrolytes (SPE) combining poly(ethylene oxide) and Nitrile Butadiene Rubber. SPE mechanical properties and ionic conductivities in the presence of 1-ethyl-3- methylimidazolium bis-(trifluoromethylsulfonyl)-imide (EMITFSI) have been characterized. The presence of the elastomer within the SPE greatly improves the actuator performances. The free strain as well as the blocking force was characterized as a function of the actuator length. The sensing properties of those conducting IPNs allow their integration into a biomimetic perception prototype: a system mimicking the tactile perception of rat vibrissae.

  3. pH-responsive amphiphilic hydrogel networks with IPN structure: a strategy for controlled drug release.

    PubMed

    Liu, Yu-Yang; Fan, Xiao-Dong; Wei, Bo-Rong; Si, Qing-Fa; Chen, Wei-Xing; Sun, Le

    2006-02-01

    A pH-responsive amphiphilic hydrogel with interpenetrating polymer networks (IPN) structure for controlled drug release was proposed. The IPN was constructed with hydrophilic poly(acrylic acid) (PAA) and hydrophobic poly(butyl acrylate) (PBA). Using drug N-acetyl-5-methoxytryptamine (melatonin, MEL) as a model molecule, the controlled drug release behaviors of the IPN were investigated. It is found that not only the release of MEL from the IPN can respond to change in pH, but also the presence of hydrophobic network can overcome disadvantageous burst effect of hydrophilic network. This may be a result of hydrophobic aggregation encapsulating MEL molecules. PMID:16321489

  4. Influence of rapid thermal cycles in multipass welding on heat-affected-zone properties in ferritic cryogenic steels

    SciTech Connect

    Kim, H.J.; Shin, H.K.; Morris, J.W. Jr.

    1982-05-01

    The results of both welding and weld simulation studies on 2BT-treated 9Ni steel show that multiple rapid thermal cycles have a very beneficial effect on heat-affected zone toughness at cryogenic temperatures. The metallurgical sources of toughness are, however, different from those in the furnace-treated base plate. The rapidly cycled material contains no detectable austenite phase. The alloy is grain-refined by the rapid thermal cycle, and the matrix carbon content is relieved by the formation of interlathcementite precipitates which do not destroy toughness.

  5. Incomplete Denitrification Causes Rapid Nitrous Oxide Cycling in the Oceanic Oxygen Minimum Zones

    NASA Astrophysics Data System (ADS)

    Babbin, A. R.; Ward, B. B.; Stocker, R.

    2015-12-01

    Nitrous oxide (N2O) is a powerful greenhouse gas and a major cause of stratospheric ozone depletion, yet its sources and sinks remain poorly quantified in the oceans. We used isotope tracers to directly measure N2O reduction rates in the eastern tropical North Pacific. Because of incomplete denitrification, N2O cycling rates are an order of magnitude higher than predicted by current models in suboxic regions, and the spatial distribution suggests strong dependence on both organic carbon and dissolved oxygen concentrations. Furthermore, N2O turnover is 20 times higher than the net atmospheric efflux. The rapid rate of this cycling coupled to an expected expansion of suboxic ocean waters implies future increases in N2O emissions.

  6. The Rapid Transit System That Achieves Higher Performance with Lower Life-Cycle Costs

    NASA Astrophysics Data System (ADS)

    Sone, Satoru; Takagi, Ryo

    In the age of traction system made of inverter and ac traction motors, distributed traction system with pure electric brake of regenerative mode has been recognised very advantageous. This paper proposes a new system as the lowest life-cycle cost system for high performance rapid transit, a new architecture and optimum parameters of power feeding system, and a new running method of trains. In Japan, these components of this proposal, i.e. pure electric brake and various countermeasures of reducing loss of regeneration have been already popular but not as yet the new running method for better utilisation of the equipment and for lower life-cycle cost. One example of what are proposed in this paper will be made as Tsukuba Express, which is under construction as the most modern commuter railway in Greater Tokyo area.

  7. Magnetic Cycles and Buoyant Magnetic Structures in a Rapidly Rotating Sun

    NASA Astrophysics Data System (ADS)

    Nelson, Nicholas J.; Brown, B. P.; Brun, S.; Miesch, M. S.; Toomre, J.

    2011-01-01

    Observations of sun-like stars rotating faster than our current sun show that they exhibit solar-like magnetic cycles and features, such as star spots. Using global 3-D simulations to study the coupling of large-scale convection, rotation, and magnetism in a younger sun, we have probed the effects of more rapid rotation on stellar dynamos and the nature of magnetic cycles. Our anelastic spherical harmonics (ASH) code allows study of the convective envelope, occupying the outer 30% by radius of a sun-like star. Major MHD simulations carried out at three times the current solar rotation rate reveal magnetic dynamo action that can produce wreaths of strong toroidal magnetic field at low latitudes, often with opposite polarity in the two hemispheres. The presence of the wreaths is quite surprising, for they arise as quite persistent global structures amidst the vigorous and turbulent convection. We have recently explored behavior in systems with considerably lower diffusivities, achieved with a dynamic Smagorinsky treatment of unresolved turbulence. The lower levels of diffusion create magnetic wreaths that undergo prominent variations in field strength, even exhibiting global magnetic cycles that involve polarity reversals. Additionally, during the cycle maximum, when magnetic energies and mean magnetic fields peak, the wreaths possess buoyant magnetic structures that rise coherently through much of the convective envelope via a combination of advection by convective upflows and magnetic buoyancy. We explore aspects of these rising magnetic structures and the evolving global dynamo action which produces them.

  8. Space Suit Portable Life Support System Rapid Cycle Amine Repackaging and Sub-Scale Test Results

    NASA Technical Reports Server (NTRS)

    Paul, Heather L.; Rivera, Fatonia L.

    2010-01-01

    NASA is developing technologies to meet requirements for an extravehicular activity (EVA) Portable Life Support System (PLSS) for exploration. The PLSS Ventilation Subsystem transports clean, conditioned oxygen to the pressure garment for space suit pressurization and human consumption, and recycles the ventilation gas, removing carbon dioxide, humidity, and trace contaminants. This paper provides an overview of the development efforts conducted at the NASA Johnson Space Center to redesign the Rapid Cycle Amine (RCA) canister and valve assembly into a radial flow, cylindrical package for carbon dioxide and humidity control of the PLSS ventilation loop. Future work is also discussed.

  9. Multi-function ring magnet power supply for rapid-cycling synchrotrons

    SciTech Connect

    Praeg, W.F.

    1985-01-01

    Ring magnet power supply (RMPS) circuits that produce a wide range of magnet current waveshapes for rapid-cycling synchrotrons (RCS) are described. The shapes range from long flat-tops separated by a biased dual frequency cosine wave to those having a flat-bottom (injection), followed by a lower frequency cosine half wave (acceleration), a flat-top (extraction), and a higher frequency cosine half wave (magnet reset). Applications of these circuits for proposed synchrotrons are outlined. Solid-state switching circuits and the results of proof-of-concept tests are shown. 8 refs., 12 figs.

  10. Rapid alterations of cell cycle control proteins in human T lymphocytes in microgravity

    PubMed Central

    2012-01-01

    In our study we aimed to identify rapidly reacting gravity-responsive mechanisms in mammalian cells in order to understand if and how altered gravity is translated into a cellular response. In a combination of experiments using "functional weightlessness" provided by 2D-clinostats and real microgravity provided by several parabolic flight campaigns and compared to in-flight-1g-controls, we identified rapid gravity-responsive reactions inside the cell cycle regulatory machinery of human T lymphocytes. In response to 2D clinorotation, we detected an enhanced expression of p21 Waf1/Cip1 protein within minutes, less cdc25C protein expression and enhanced Ser147-phosphorylation of cyclinB1 after CD3/CD28 stimulation. Additionally, during 2D clinorotation, Tyr-15-phosphorylation occurred later and was shorter than in the 1 g controls. In CD3/CD28-stimulated primary human T cells, mRNA expression of the cell cycle arrest protein p21 increased 4.1-fold after 20s real microgravity in primary CD4+ T cells and 2.9-fold in Jurkat T cells, compared to 1 g in-flight controls after CD3/CD28 stimulation. The histone acetyltransferase (HAT) inhibitor curcumin was able to abrogate microgravity-induced p21 mRNA expression, whereas expression was enhanced by a histone deacetylase (HDAC) inhibitor. Therefore, we suppose that cell cycle progression in human T lymphocytes requires Earth gravity and that the disturbed expression of cell cycle regulatory proteins could contribute to the breakdown of the human immune system in space. PMID:22273506

  11. Evaluation of rapid cell division in non-uniform cell cycles.

    PubMed

    Lee, Juyun; Jeon, Wonju; Chang, Man; Han, Myung-Soo

    2015-10-01

    To better understand the mechanisms of development of harmful algal blooms (HABs), accurate estimates of species-specific in situ growth rates are needed. HABs are caused by rapid cell division by the causative microorganisms. To accurately estimate the in situ growth rates of harmful algae having non-uniform and/or irregular cell cycles, we modified a standard equation based on the cell cycle, and calculated the in situ growth rate to describe the process of bloom development in nature. Sampling of a developing bloom of Heterosigma akashiwo in Pohang Bay, Korea, was conducted every 3 h from 15:00 on August 2 to 07:00 on August 4, 2006. The amount of H. akashiwo DNA was measured using flow cytometry following tyramide signal amplification-fluorescence in situ hybridization. On August 2, the percentage of G1 phase cells decreased from 15:00 to 19:00 then increased until 22:00; it then decreased until 07:00 on August 3, followed by an increase to 10:00. This indicates the ability of the cells in nature to undergo more than one round of division per day. During the following night two rounds of division did not occur. The in situ growth rates estimated using the modified equation ranged from 0.31 to 0.53 d(-1) . We conclude that the use of this equation enables more accurate estimates of bloom formation by rapidly dividing cells. PMID:26175341

  12. RAPID RELEASE OF N-LINKED GLYCANS FROM GLYCOPROTEINS BY PRESSURE CYCLING TECHNOLOGY

    PubMed Central

    Szabo, Zoltan; Guttman, András; Karger, Barry L.

    2010-01-01

    The standard, well-established sample preparation protocol to release N-linked glycans from glycoproteins for downstream analysis requires relatively long deglycosylation times (from several hours to overnight) and relatively high endoglycosidase concentration (1:250 – 1:500 enzyme:substrate molar ratio). In this paper, we significantly improve this standard protocol by the use of pressure cycling technology (PCT) to increase the speed and decrease the relative amount of PNGase F during the release of N-linked glycans from denatured glycoproteins. With the application of pressure cycling from atmospheric to as high as 30 kPsi, >95% release of the asparagine linked glycans from bovine ribonuclease B, human transferrin and polyclonal human immunoglobulin was rapidly achieved in a few minutes using as low as 1:2500 enzyme:substrate molar ratio. The deglycosylation rate was first examined by SDS-PAGE at the protein level. The released glycans were then quantitated by capillary electrophoresis with laser induced fluorescence detection (CE-LIF). This new sample preparation protocol readily supports large scale glycan analysis of biopharmaceuticals with rapid deglycosylation times. PMID:20170179

  13. IPN, Institut fur die Padagogik der Naturwissenschaften (Institute for Science Education).

    ERIC Educational Resources Information Center

    Kiel Univ. (West Germany). Institut fuer die Paedagogik der Naturwissenschaften.

    The Institute for Science Education (IPN) at the University of Kiel is a supraregional research Institute which conducts research, through multidisciplinary approaches, in the field of science education. The IPN carries on this research from the psychological and social aspects, develops science curriculum materials, and evaluates their effects in…

  14. IPN hydrogel nanocomposites based on agarose and ZnO with antifouling and bactericidal properties.

    PubMed

    Wang, Jingjing; Hu, Hongkai; Yang, Zhonglin; Wei, Jun; Li, Juan

    2016-04-01

    Nanocomposite hydrogels with interpenetrating polymer network (IPN) structure based on poly(ethylene glycol) methyl ether methacrylate modified ZnO (ZnO-PEGMA) and 4-azidobenzoic agarose (AG-N3) were prepared by a one-pot strategy under UV irradiation. The hydrogels exhibited a highly macroporous spongelike structure, and the pore size decreased with the increase of the ZnO-PEGMA content. Due to the entanglement and favorable interactions between the two crosslinked networks, the IPN hydrogels exhibited excellent mechanical strength and light transmittance. The maximum compressive and tensile strengths of the IPN hydrogels reached 24.8 and 1.98 MPa respectively. The transparent IPN hydrogels transmitted more than 85% of visible light at all wavelengths (400-800 nm). The IPN hydrogels exhibited anti-adhesive property towards Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus), and the bactericidal activity increased with the ZnO-PEGMA content. The incorporation of ZnO-PEGMA did not reduce the biocompatibility of the IPN hydrogels and all the IPN nanocomposites showed negligible cytotoxicity. The present study not only provided a facile method for preparing hydrogel nanocomposites with IPN structure but also developed a new hydrogel material which might be an excellent candidate for wound dressings. PMID:26838864

  15. Rapid alterations of avian medullary bone material during the daily egg-laying cycle.

    PubMed

    Kerschnitzki, Michael; Zander, Thomas; Zaslansky, Paul; Fratzl, Peter; Shahar, Ron; Wagermaier, Wolfgang

    2014-12-01

    Bone is a dynamic tissue which is continuously adapting not only to external mechanical stimuli but also to internal metabolic calcium demands. During normal bone remodeling, bone-resorbing osteoclasts release calcium from the bone and digest the collagenous bone matrix, after which bone-depositing osteoblasts form unmineralized collagen matrix, which subsequently mineralizes. The detailed mechanism by which calcium is deposited at the site of mineralization and removed from it during bone resorption is largely unknown. Experimental studies are difficult to conduct because in adult bone only a small fraction of bone tissue is remodeled at any moment in time. Thus, one promising approach is to study mineral deposition and resorption in model systems in which a large fraction of the bone mineral is mobilized in a relatively short period of time. We investigated the microscopic and nanoscopic alterations of avian medullary bone architecture during the egg-laying (oviposition) cycle of hens. Medullary bone forms a labile calcium reservoir for eggshell production and is characterized by an extremely rapid and high-flux calcium metabolism. It thus, provides the unique opportunity to study processes of bone remodeling in their most intensive form. We used a combination of synchrotron X-ray tomography together with small angle X-ray scattering (SAXS), wide angle X-ray diffraction (WAXD) and X-ray fluorescence (XRF) to correlate microscopic medullary bone attributes such as the mineral content, medullary bone volume fraction and medullary bone trabecular thickness with nanoscopic alterations in the mineral particle size (thickness parameter T and length parameter L) during the oviposition cycle. To identify the timing of the different stages of the cycle, ionic calcium, phosphorus and PTH concentrations in the blood of the layers were monitored. We found that the microscopic and nanoscopic architecture of avian medullary bone material changes rapidly during the oviposition

  16. Daytime spikes in dopaminergic activity drive rapid mood-cycling in mice.

    PubMed

    Sidor, M M; Spencer, S M; Dzirasa, K; Parekh, P K; Tye, K M; Warden, M R; Arey, R N; Enwright, J F; Jacobsen, J P R; Kumar, S; Remillard, E M; Caron, M G; Deisseroth, K; McClung, C A

    2015-11-01

    Disruptions in circadian rhythms and dopaminergic activity are involved in the pathophysiology of bipolar disorder, though their interaction remains unclear. Moreover, a lack of animal models that display spontaneous cycling between mood states has hindered our mechanistic understanding of mood switching. Here, we find that mice with a mutation in the circadian Clock gene (ClockΔ19) exhibit rapid mood-cycling, with a profound manic-like phenotype emerging during the day following a period of euthymia at night. Mood-cycling coincides with abnormal daytime spikes in ventral tegmental area (VTA) dopaminergic activity, tyrosine hydroxylase (TH) levels and dopamine synthesis. To determine the significance of daytime increases in VTA dopamine activity to manic behaviors, we developed a novel optogenetic stimulation paradigm that produces a sustained increase in dopamine neuronal activity and find that this induces a manic-like behavioral state. Time-dependent dampening of TH activity during the day reverses manic-related behaviors in ClockΔ19 mice. Finally, we show that CLOCK acts as a negative regulator of TH transcription, revealing a novel molecular mechanism underlying cyclic changes in mood-related behavior. Taken together, these studies have identified a mechanistic connection between circadian gene disruption and the precipitation of manic episodes in bipolar disorder. PMID:25560763

  17. Daytime spikes in dopaminergic activity drive rapid mood-cycling in mice

    PubMed Central

    Sidor, Michelle M.; Spencer, Sade M.; Dzirasa, Kafui; Parekh, Puja K.; Tye, Kay M.; Warden, Melissa R.; Arey, Rachel N.; Enwright, John F; Jacobsen, Jacob PR; Kumar, Sunil; Remillard, Erin M; Caron, Marc G.; Deisseroth, Karl; McClung, Colleen A

    2014-01-01

    Disruptions in circadian rhythms and dopaminergic activity are involved in the pathophysiology of bipolar disorder, though their interaction remains unclear. Moreover, a lack of animal models that display spontaneous cycling between mood states has hindered our mechanistic understanding of mood switching. Here we find that mice with a mutation in the circadian Clock gene (ClockΔ19) exhibit rapid mood-cycling, with a profound manic-like phenotype emerging during the day following a period of euthymia at night. Mood cycling coincides with abnormal daytime spikes in ventral tegmental area (VTA) dopaminergic activity, tyrosine hydroxylase (TH) levels, and dopamine synthesis. To determine the significance of daytime increases in VTA dopamine activity to manic behaviors, we developed a novel optogenetic stimulation paradigm that produces a sustained increase in dopamine neuronal activity and find that this induces a manic-like behavioral state. Time-dependent dampening of TH activity during the day reverses manic-related behaviours in ClockΔ19 mice. Finally, we show that CLOCK acts as a negative regulator of TH transcription, revealing a novel molecular mechanism underlying cyclic changes in mood-related behaviour. Taken together, these studies have identified a mechanistic connection between circadian gene disruption and the precipitation of manic episodes in bipolar disorder. PMID:25560763

  18. Realizing the potential of rapid-cycling Brassica as a model system for use in plant biology research

    NASA Technical Reports Server (NTRS)

    Musgrave, M. E.

    2000-01-01

    Rapid-cycling Brassica populations were initially developed as a model for probing the genetic basis of plant disease. Paul Williams and co-workers selected accessions of the six main species for short time to flower and rapid seed maturation. Over multiple generations of breeding and selection, rapid-cycling populations of each of the six species were developed. Because of their close relationship with economically important Brassica species, rapid-cycling Brassica populations, especially those of B. rapa (RCBr) and B. oleracea, have seen wide application in plant and crop physiology investigations. Adding to the popularity of these small, short-lived plants for research applications is their extensive use in K-12 education and outreach.

  19. Reconsidering Tree Fruit as Candidate Crops Through the Use of Rapid Cycle Crop Breeding Technologies

    NASA Technical Reports Server (NTRS)

    Graham, Gary Thomas

    2014-01-01

    Tree fruit, although desirable from a crew nutrition and menu diversity perspective, have long been dismissed as candidate crops based on their long juvenile phase, large architecture, low short-term harvest index, and dormancy requirements. Recent developments in Rapid Cycle Crop Breeding (RCCB) have overcome these historical limitations, opening the door to a new era in candidate crop research. Researchers at the United States Department of Agriculture (USDA) have developed FT-construct (Flowering Locus T) dwarf plum lines that have a very short juvenile phase, vine-like architecture, and no obligate dormancy period. In a collaborative research effort, NASA and the USDA are evaluating the performance of these FT-lines under controlled environment conditions relevant to spaceflight.

  20. Rapid Cycling Synchrotrons and Accumulator Rings for High-Intensity Hadron Beams

    NASA Astrophysics Data System (ADS)

    Tang, Jingyu

    2014-02-01

    Boosted by the needs in high-energy physics and nuclear physics and also multidisciplinary applications, high-intensity proton synchrotrons and accumulator rings have been developed quickly around the world over the last 30 years. New projects and plans are proposed with even higher beam power. The proton beam power has increased from less than 10 kW in the 1970s to about 1 MW level today, and the required beam power in the coming decade is a few MW. This article reviews the achievements in designing and constructing rapid cycling synchrotrons (RCSs) and accumulator rings (ARs) and the future development trends, principally on proton beams but also including heavy ion beams. It presents the evolution of RCS and AR machines, today's design philosophy, relevant accelerator physics, and also state-of-the-art accelerator technology.

  1. Influence of mold surface temperature on polymer part warpage in rapid heat cycle molding

    NASA Astrophysics Data System (ADS)

    Berger, G. R.; Pacher, G. A.; Pichler, A.; Friesenbichler, W.; Gruber, D. P.

    2014-05-01

    Dynamic mold surface temperature control was examined for its influence on the warpage. A test mold, featuring two different rapid heat cycle molding (RHCM) technologies was used to manufacture complex plate-shaped parts having different ribs, varying thin-wall regions, and both, circular and rectangular cut-outs. The mold's nozzle side is equipped with the areal heating and cooling technology BFMOLD®, where the heating/cooling channels are replaced by a ball-filled slot near the cavity surface flooded through with hot and cold water sequentially. Two local electrical ceramic heating elements are installed into the mold's ejection side. Based on a 23 full-factorial design of experiments (DoE) plan, varying nozzle temperature (Tnozzle), rapid heat cycle molding temperature (TRHCM) and holding pressure (pn), specimens of POM were manufactured systematically. Five specimens were examined per DoE run. The resulting warpage was measured at 6 surface line scans per part using the non-contact confocal topography system FRT MicroProf®. Two warpage parameters were calculated, the curvature of a 2nd order approximation a, and the vertical deflection at the profile center d. Both, the influence strength and the acting direction of the process parameters and their interactions on a and d were calculated by statistical analysis. Linear mathematical process models were determined for a and d to predict the warpage as a function of the process parameter settings. Finally, an optimum process setting was predicted, based on the process models and Microsoft Excel GRG solver. Clear and significant influences of TRHCM, pn, Tnozzle, and the interaction of TRHCM and pn were determined. While TRHCM was dominant close to the gate, pn became more effective as the flow length increased.

  2. β-Arrestin biosensors reveal a rapid, receptor-dependent activation/deactivation cycle.

    PubMed

    Nuber, Susanne; Zabel, Ulrike; Lorenz, Kristina; Nuber, Andreas; Milligan, Graeme; Tobin, Andrew B; Lohse, Martin J; Hoffmann, Carsten

    2016-03-31

    (β-)Arrestins are important regulators of G-protein-coupled receptors (GPCRs). They bind to active, phosphorylated GPCRs and thereby shut off 'classical' signalling to G proteins, trigger internalization of GPCRs via interaction with the clathrin machinery and mediate signalling via 'non-classical' pathways. In addition to two visual arrestins that bind to rod and cone photoreceptors (termed arrestin1 and arrestin4), there are only two (non-visual) β-arrestin proteins (β-arrestin1 and β-arrestin2, also termed arrestin2 and arrestin3), which regulate hundreds of different (non-visual) GPCRs. Binding of these proteins to GPCRs usually requires the active form of the receptors plus their phosphorylation by G-protein-coupled receptor kinases (GRKs). The binding of receptors or their carboxy terminus as well as certain truncations induce active conformations of (β-)arrestins that have recently been solved by X-ray crystallography. Here we investigate both the interaction of β-arrestin with GPCRs, and the β-arrestin conformational changes in real time and in living human cells, using a series of fluorescence resonance energy transfer (FRET)-based β-arrestin2 biosensors. We observe receptor-specific patterns of conformational changes in β-arrestin2 that occur rapidly after the receptor-β-arrestin2 interaction. After agonist removal, these changes persist for longer than the direct receptor interaction. Our data indicate a rapid, receptor-type-specific, two-step binding and activation process between GPCRs and β-arrestins. They further indicate that β-arrestins remain active after dissociation from receptors, allowing them to remain at the cell surface and presumably signal independently. Thus, GPCRs trigger a rapid, receptor-specific activation/deactivation cycle of β-arrestins, which permits their active signalling. PMID:27007855

  3. An episode of rapid bedrock channel incision during the last glacial cycle, measured with 10Be

    USGS Publications Warehouse

    Reusser, L.; Bierman, P.; Pavich, M.; Larsen, J.; Finkel, R.

    2006-01-01

    We use 10Be to infer when, how fast, and why the Susquehanna River incised through bedrock along the U.S. Atlantic seaboard, one of the world's most prominent and ancient passive margins. Although the rate at which large rivers incise rock is a fundamental control on the development of landscapes, relatively few studies have directly measured how quickly such incision occurs either in tectonically active environments or along passive margins. Exposure ages of fluvially carve d, bedrock strath terraces, preserved along the lower Susquehanna River, demonstrate that even along a passive margin, large rivers are capable of incising through rock for short periods of time at rates approaching those recorded in tectonically active regions, such as the Himalayas. Over eighty samples, collected along and between three prominent levels of strath terraces within Holtwood Gorge, indicate that the Susquehanna River incised more than 10 meters into the Appalachian Piedmont during the last glacial cycle. Beginning ???36 ka, incision rates increased dramatically, and remained elevated until ???14 ka. The northern half of the Susquehanna basin was glaciated during the late Wisconsinan; however, similar rates and timing of incision occurred in the unglaciated Potomac River basin immediately to the south. The concurrence of incision periods on both rivers suggests that glaciation and associated meltwater were not the primary drivers of incision. Instead, it appears that changing climatic conditions during the late Pleistocene promoted an increase in the frequency and magnitude of flood events capable of exceeding thresholds for rock detachment and bedrock erosion, thus enabling a short-lived episode of rapid incision into rock. Although this study has constraine d the timing and rate of bedrock incision along the largest river draining the Atlantic passive margin, the dates alone cannot explain fully why, or by what processes, this incision occurred. However, cosmogenic dating offers

  4. Parasitic slow extraction of extremely weak beam from a high-intensity proton rapid cycling synchrotron

    NASA Astrophysics Data System (ADS)

    Zou, Ye; Tang, Jingyu; Yang, Zheng; Jing, Hantao

    2014-02-01

    This paper proposes a novel method to extract extremely weak beam from a high-intensity proton rapid cycling synchrotron (RCS) in the parasitic mode, while maintaining the normal fast extraction. The usual slow extraction method from a synchrotron by employing third-order resonance cannot be applied in a high-intensity RCS due to a very short flat-top at the extraction energy and the strict control on beam loss. The proposed parasitic slow extraction method moves the beam to scrape a scattering foil prior to the fast beam extraction by employing either a local orbit bump or momentum deviation or their combination, so that the halo part of the beam will be scattered. A part of the scattered particles will be extracted from the RCS and guided to the experimental area. The slow extraction process can last about a few milliseconds before the beam is extracted by the fast extraction system. The method has been applied to the RCS of China Spallation Neutron Source. With 1.6 GeV in the extraction energy, 62.5 μA in the average current and 25 Hz in the repetition rate for the RCS, the proton intensity by the slow extraction method can be up to 2×104 protons per cycle or 5×105 protons per second. The extracted beam has also a good time structure of approximately uniform in a spill which is required for many applications such as detector tests. Detailed studies including the scattering effect in the foil, the local orbit bump by the bump magnets and dispersive orbit bump by modifying the RF pattern, the multi-particle simulations by ORBIT and TURTLE codes, and some technical features for the extraction magnets are presented.

  5. Supercontinuum based absorption spectrometer for cycle-resolved multiparameter measurements in a rapid compression machine.

    PubMed

    Werblinski, Thomas; Kleindienst, Stefan; Engelbrecht, Rainer; Zigan, Lars; Will, Stefan

    2016-06-10

    A broadband supercontinuum (SC) based absorption spectrometer capable of cycle-resolved multiparameter measurements at internal combustion (IC) engine conditions is presented. Three parameters, temperature, pressure and water mole fraction, were extracted from broadband near-infrared H2O absorption spectra, spanning the wavelength-range from 1340 to 1405.5 nm, which exhibits a large number of specific H2O transitions. The spectrometer is based on spatial domain detection and features a near-infrared line scan camera as a detector. Measurements were performed during a compression cycle of a rapid compression machine comprising a pressure and temperature range from 2.5 to 65 bar and 300 to 900 K, respectively. With the new spectrometer, we are for the first time, based on the authors' knowledge, able to perform measurements based on SC radiation over a complete compression and expansion stroke at measurement rates up to 50 kHz. A detailed overview is provided about the best match algorithm between theory and experiments, including parameters from two different spectral databases, namely the Barber-Tennyson database (BT2) and HITRAN2012. The results indicate that spectral broadening effects are not properly described by theory, especially at pressure levels exceeding 20 bar, which culminates in a clear underestimation of the derived pressure data by SC absorption spectroscopy. Nevertheless, temperature can be determined accurately by performing a three-parameter fit based on water mole fraction, temperature, and pressure. In contrast, making use of pressure transducer data as look-up values and varying only temperature and H2O mole fraction to find the best match leads to a clear overestimation of temperature at elevated pressures. PMID:27409013

  6. Rapid response of the steatosis-sensing hepatokine LECT2 during diet-induced weight cycling in mice.

    PubMed

    Chikamoto, Keita; Misu, Hirofumi; Takayama, Hiroaki; Kikuchi, Akihiro; Ishii, Kiyo-Aki; Lan, Fei; Takata, Noboru; Tajima-Shirasaki, Natsumi; Takeshita, Yumie; Tsugane, Hirohiko; Kaneko, Shuichi; Matsugo, Seiichi; Takamura, Toshinari

    2016-09-23

    Dieting often leads to body weight cycling involving repeated weight loss and regain. However, little information is available regarding rapid-response serum markers of overnutrition that predict body weight alterations during weight cycling. Here, we report the rapid response of serum leukocyte cell-derived chemotaxin 2 (LECT2), a hepatokine that induces insulin resistance in skeletal muscle, during diet-induced weight cycling in mice. A switch from a high-fat diet (HFD) to a regular diet (RD) in obese mice gradually decreased body weight but rapidly decreased serum LECT2 levels within 10 days. In contrast, a switch from a RD to a HFD rapidly elevated serum LECT2 levels. Serum LECT2 levels showed a positive correlation with liver triglyceride contents but not with adipose tissue weight. This study demonstrates the rapid response of LECT2 preceding body weight alterations during weight cycling in mice and suggests that measurement of serum LECT2 may be clinically useful in the management of obesity. PMID:27562717

  7. Rapid Quench Cold-Seal Apparatus with Computer-Controlled Pressure and Temperature Cycling

    NASA Astrophysics Data System (ADS)

    Johnston, A.; Senkovich, D.

    2007-12-01

    We have constructed two computer-controlled, rapid quench, hydrothermal apparatuses that are ideal for experimentation on volcanological, geothermal, and ore deposit research problems. The devices can achieve maximum pressures of about 2 kbar and temperatures to 1100C, have the ability for experiments to be quenched very rapidly in a water-cooled environment, and are interfaced with computers which can control any regimen of pressure and/or temperature cycling that may be desired, accomplished via Lab-View software and data acquisition and motion control boards from National Instruments. The rapid quench aspects of the design were developed originally by Dr. Phil Ihinger and have subsequently been adopted by many labs around the world; a good summary description of these aspects of the equipment, and the use of filler-rods for controlling redox conditions in such equipment, are provided by Matthews et al. (2004, Am. Mineral., 88: 701-707). Our design has fixed Rene 41 pressure vessels, furnaces that are raised and lowered by computer controlled pneumatic cylinders and water cooling systems that are controlled by computer operated solenoid valves. The novel feature of our design is the pressure generation and control systems. We coupled the seal-ends of commercially available (HIP) pressure generators to shop-built linear actuators consisting of nearly frictionless ball lead screws within thick walled stainless steel housings. These in turn are driven by NEMA size 23 stepper motors coupled to 100:1 gear reduction units. The actuators require 21 revolutions to achieve their full stroke of 12.7 cm which displaces about 10 cc of fluid. Operating the motors at the relatively low resolution of 800 steps per revolution leads to about 132,000 steps per cm of travel of the pressure-generating piston, providing exceptionally high precision and excellent pressure control. Instantaneous decompression can be achieved by simply opening a valve while motor

  8. The Institute for Science Education-IPN, at Kiel, FR Germany.

    ERIC Educational Resources Information Center

    Frey, Karl

    1980-01-01

    Describes the activities of The Institute for Science Education (IPN) at the University of Kiel, Germany. The emphasis is on the interdisciplinary approach of the individual fields and the projects during 1977-1979. (SA)

  9. Patterning process and actuation in open air of micro-beam actuator based on conducting IPNs

    NASA Astrophysics Data System (ADS)

    Khaldi, Alexandre; Plesse, Cédric; Soyer, Caroline; Chevrot, Claude; Teyssié, Dominique; Vidal, Frédéric; Cattan, Eric

    2012-04-01

    We report on new method to obtain micrometric electroactive polymer actuators operating in air. High speed conducting Interpenetrating Polymer Network (IPN) microactuators are synthesized and fully characterized. The IPN architecture used in this work allows solving the interface and adhesion problems, which have been reported in the design of classical conducting polymer-based actuators. We demonstrated that it is possible to reduce the thickness of these actuators by a specific synthetic pathway. IPN host matrixes based on polyethylene oxide / polytetrahydrofurane have been shaped by hot pressing. Then, the resulting thin host matrixes (below 10 μm) are compatible with the microfabrication technologies. After interpenetration of poly(3,4-ethylenedioxythiophene) (PEDOT), these electroactive materials are micro-sized using dry etching process. Frequency responses and displacement have been characterized by scanning electronic microscopy. These conducting IPN microactuators can be considered as potential candidates in numerous low frequency applications, including micro-valves, micro-optical instrumentation and micro-robotics.

  10. Continued Development of the Rapid Cycle Amine (RCA) System for Advanced Extravehicular Activity Systems

    NASA Technical Reports Server (NTRS)

    Papale, William; Chullen, Cinda; Campbell, Colin; Conger, Bruce; McMillin, Summer; Jeng, Frank

    2014-01-01

    Development activities related to the Rapid Cycle Amine (RCA) Carbon Dioxide (CO2) and Humidity control system have progressed to the point of integrating the RCA into an advanced Primary Life Support System (PLSS 2.0) to evaluate the interaction of the RCA among other PLSS components in a ground test environment. The RCA 2.0 assembly (integrated into PLSS 2.0) consists of a valve assembly with commercial actuator motor, a sorbent canister, and a field-programmable gate array (FPGA)-based process node controller. Continued design and development activities for RCA 3.0 have been aimed at optimizing the canister size and incorporating greater fidelity in the valve actuator motor and valve position feedback design. Further, the RCA process node controller is envisioned to incorporate a higher degree of functionality to support a distributed PLSS control architecture. This paper will describe the progression of technology readiness levels of RCA 1.0, 2.0 and 3.0 along with a review of the design and manufacturing successes and challenges for 2.0 and 3.0 units. The anticipated interfaces and interactions with the PLSS 2.0/2.5/3.0 assemblies will also be discussed.

  11. Maintaining Adequate CO2 Washout for an Advanced EMU via a New Rapid Cycle Amine Technology

    NASA Technical Reports Server (NTRS)

    Chullen, Cinda; Conger, Bruce

    2012-01-01

    Over the past several years, NASA has realized tremendous progress in Extravehicular Activity (EVA) technology development. This has been evidenced by the progressive development of a new Rapid Cycle Amine (RCA) system for the Advanced Extravehicular Mobility Unit (AEMU) Portable Life Support Subsystem (PLSS). The PLSS is responsible for the life support of the crew member in the spacesuit. The RCA technology is responsible for carbon dioxide (CO2) and humidity control. Another aspect of the RCA is that it is on-back vacuum-regenerable, efficient, and reliable. The RCA also simplifies the PLSS schematic by eliminating the need for a condensing heat exchanger for humidity control in the current EMU. As development progresses on the RCA, it is important that the sizing be optimized so that the demand on the PLSS battery is minimized. As well, maintaining the CO2 washout at adequate levels during an EVA is an absolute requirement of the RCA and associated ventilation system. Testing has been underway in-house at NASA Johnson Space Center and analysis has been initiated to evaluate whether the technology provides exemplary performance in ensuring that the CO2 is removed sufficiently and the ventilation flow is adequate for maintaining CO2 washout in the AEMU spacesuit helmet of the crew member during an EVA. This paper will review the recent developments of the RCA unit, testing planned in-house with a spacesuit simulator, and the associated analytical work along with insights from the medical aspect on the testing. 1

  12. Assessment of the 60 km Rapid Update Cycle (RUC) with Near Real-Time Aircraft Reports

    NASA Technical Reports Server (NTRS)

    Cole, R. E.; Richard, C.; Kim, S.; Bailey, D.

    1998-01-01

    The National Aeronautics and Space Administration (NASA) is developing the Center-TRA-CON Advisory System (CTAS), a set of Air Traffic Management (ATM) Decision Support Tools (DST) for en route (Center) and terminal (TRACON) airspace designed to enable controllers to increase capacity and flight efficiency. A crucial component of the CTAS, or any ATM DST, is the computation of the time-of-flight of aircraft along flight path segments. Earlier NASA studies show that accurate knowledge of the wind through which the aircraft are flying is required to estimate time-of-flight accurately. There are current envisioned to be two sources of wind data for CTAS: The Rapid Update Cycle (RUC) for the Center airspace, a numerical model developed by the National Oceanic and Atmospheric Administration (NOAA) Forecast System Laboratory (FSL) and run operationally by the National Weather Service (NWS) National Center for Environmental Prediction (NCEP); and The Integrated Terminal Weather System (ITWS) Terminal Winds (TW) for the TRACON airspace, developed at MIT Lincoln Laboratory under funding from the Federal Aviation Administration (FAA). This study has three goals: (1) determine the errors in the baseline 60 km resolution RUC forecast wind fields relative to the needs of en route DSTs such as CTAS, (2) determine the benefit of using the TW algorithm to refine the RUC forecast wind fields with near real-time Meteorological Data Collection and Reporting System (MDCRS) reports, and (3) identify factors that influence wind errors in order to improve accuracy and estimate errors in real time.

  13. Rapid and Efficient Protein Digestion using Trypsin Coated Magnetic Nanoparticles under Pressure Cycles

    SciTech Connect

    Lee, Byoungsoo; Lopez-Ferrer, Daniel; Kim, Byoung Chan; Na, Hyon Bin; Park, Yong Il; Weitz, Karl K.; Warner, Marvin G.; Hyeon, Taeghwan; Lee, Sang-Won; Smith, Richard D.; Kim, Jungbae

    2011-01-01

    Trypsin-coated magnetic nanoparticles (EC-TR/NPs), prepared via a simple crosslinking of the enzyme to magnetic nanoparticles, were highly stable and could be easily captured using a magnet after the digestion was complete. EC-TR/NPs showed a negligible loss of trypsin activity after multiple uses and continuous shaking, while a control sample of covalently-attached trypsin on NPs resulted in a rapid inactivation under the same conditions due to the denaturation and autolysis of trypsin. Digestions were carried out on a single model protein, a five protein mixture, and a whole mouse brain proteome, and also compared for digestion at atmospheric pressure and 37 ºC for 12 h, and in combination with pressure cycling technology (PCT) at room temperature for 1 min. In all cases, the EC-TR/NPs performed equally as well or better than free trypsin in terms of the number of peptide/protein identifications and reproducibility across technical replicates. However, the concomitant use of EC-TR/NPs and PCT resulted in very fast (~1 min) and more reproducible digestions.

  14. Preparation and characterization of a novel magnetorheological elastomer based on polyurethane/epoxy resin IPNs matrix

    NASA Astrophysics Data System (ADS)

    Yu, M.; Qi, S.; Fu, J.; Yang, P. A.; Zhu, M.

    2015-04-01

    This paper proposes the preparation of a novel magnetorheological elastomer (MRE) with improved damping and mechanical properties. This MRE is based on polyurethane (PU)/epoxy resin (EP) graft interpenetrating polymer networks (IPNs). The tensile strengths, thermal stability, magnetorhelogical behavior, and damping properties of the MRE are studied systematically in terms of composition. The Fourier transform infrared (FTIR) spectra verifies the formation of IPN structures, and thermogravimetric analysis (TGA) revealed that the thermal decomposition temperature was raised by the addition of IPN structures. The test results from the materials test machine and the rheometer show that the presence of IPN can significantly improve the tensile strength and damping properties of the MRE. In addition, the mechanism for enhancing tensile strength and damping properties is proposed. The experiment results suggest that the damping performance of the MRE has a significant correlation with the magnetic strength, content of EP, and temperature. As the thermal endurance properties, tensile strength, and loss factor are improved by incorporating EP/PU IPN structure, it is expected that the PU/EP IPN MRE can be used as an intelligent structural damping material.

  15. Fast Plants for Finer Science--An Introduction to the Biology of Rapid-Cycling Brassica Campestris (rapa) L.

    ERIC Educational Resources Information Center

    Tomkins, Stephen P.; Williams, Paul H.

    1990-01-01

    Rapid-cycling brassicas can be used in the classroom to teach concepts such as plant growth, tropisms, floral reproduction, pollination, embryonic development, and plant genetics. Directions on how to obtain them for classroom use and how they may be grown are included. Practical physiology and genetics exercises are listed. (KR)

  16. MiniMax, a new diminutive Glycine max genotype with a rapid life cycle, embryonic potential and transformation capabilities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glycine max cv MiniMax has a rapid life cycle, short stature and characteristic simple sequence repeats (SSR) markers that make it useful for genetic mapping studies. The development of MiniMax that has many properties of a desirable genetic system prompted the evaluation of its ability to be grown ...

  17. A Method to Teach Age-Specific Demography with Field Grown Rapid Cycling "Brassica rapa" (Wisconsin Fast Plants)

    ERIC Educational Resources Information Center

    Kelly, Martin G.; Terrana, Sebastian

    2004-01-01

    In this paper, we demonstrate that rapid cycling "Brassica rapa" (Wisconsin Fast Plants) can be used in inquiry-based, student ecological fieldwork. We are the first to describe age-specific survival for field-grown Fast Plants and identify life history traits associated with individual survival. This experiment can be adapted by educators as a…

  18. Development of Public Immortal Mapping Populations, Molecular Markers, and Linkage Maps for Rapid Cycling Brassica rapa and B. oleracea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Past research efforts on genetic mapping in Brassica oleracea and Brassica rapa have been disconnected, utilizing separate mapping populations and different sets of molecular markers. Here we present public immortal mapping populations, molecular markers and linkage maps for rapid cycling B. rapa a...

  19. SU-E-T-303: Spot Scanning Dose Delivery with Rapid Cycling Proton Beams From RCMS

    SciTech Connect

    Cheng, C; Liu, H; Lee, S

    2014-06-01

    Purpose: A rapid cycling proton beam has several distinct characteristics superior to a slow extraction synchrotron: The beam energy and energy spread, beam intensity and spot size can be varied spot by spot. The feasibility of using a spot scanning beam from a rapidc-ycling-medical-synchrotron (RCMS) at 10 Hz repetition frequency is investigated in this study for its application in proton therapy. Methods: The versatility of the beam is illustrated by two examples in water phantoms: (1) a cylindrical PTV irradiated by a single field and (2) a spherical PTV irradiated by two parallel opposed fields. A uniform dose distribution is to be delivered to the volumes. Geant4 Monte Carlo code is used to validate the dose distributions in each example. Results: Transverse algorithms are developed to produce uniform distributions in each transverseplane in the two examples with a cylindrical and a spherical PTV respectively. Longitudinally, different proton energies are used in successive transverse planes toproduce the SOBP required to cover the PTVs. In general, uniformity of dosedistribution within 3% is obtained for the cylinder and 3.5% for the sphere. The transversealgorithms requires only few hundred beam spots for each plane The algorithms may beapplied to larger volumes by increasing the intensity spot by spot for the same deliverytime of the same dose. The treatment time can be shorter than 1 minute for any fieldconfiguration and tumor shape. Conclusion: The unique beam characteristics of a spot scanning beam from a RCMS at 10 Hz repetitionfrequency are used to design transverse and longitudinal algorithms to produce uniformdistribution for any arbitrary shape and size of targets. The proposed spot scanning beam ismore versatile than existing spot scanning beams in proton therapy with better beamcontrol and lower neutron dose. This work is supported in part by grants from the US Department of Energy under contract; DE-FG02-12ER41800 and the National Science

  20. Real-Time Patient Survey Data During Routine Clinical Activities for Rapid-Cycle Quality Improvement

    PubMed Central

    Jones, Robert E

    2015-01-01

    Background Surveying patients is increasingly important for evaluating and improving health care delivery, but practical survey strategies during routine care activities have not been available. Objective We examined the feasibility of conducting routine patient surveys in a primary care clinic using commercially available technology (Web-based survey creation, deployment on tablet computers, cloud-based management of survey data) to expedite and enhance several steps in data collection and management for rapid quality improvement cycles. Methods We used a Web-based data management tool (survey creation, deployment on tablet computers, real-time data accumulation and display of survey results) to conduct four patient surveys during routine clinic sessions over a one-month period. Each survey consisted of three questions and focused on a specific patient care domain (dental care, waiting room experience, care access/continuity, Internet connectivity). Results Of the 727 available patients during clinic survey days, 316 patients (43.4%) attempted the survey, and 293 (40.3%) completed the survey. For the four 3-question surveys, the average time per survey was overall 40.4 seconds, with a range of 5.4 to 20.3 seconds for individual questions. Yes/No questions took less time than multiple choice questions (average 9.6 seconds versus 14.0). Average response time showed no clear pattern by order of questions or by proctor strategy, but monotonically increased with number of words in the question (<20 words, 21-30 words, >30 words)—8.0, 11.8, 16.8, seconds, respectively. Conclusions This technology-enabled data management system helped capture patient opinions, accelerate turnaround of survey data, with minimal impact on a busy primary care clinic. This new model of patient survey data management is feasible and sustainable in a busy office setting, supports and engages clinicians in the quality improvement process, and harmonizes with the vision of a learning health

  1. The Resonance Laser Ion Source at Ipn-Atlo

    NASA Astrophysics Data System (ADS)

    Li, R.; Franchoo, S.; Lau, C.; Fedosseev, V.; Goodacre, T. D.; March, B.; Flanagan, K.; Kron, T.; Wendt, K.

    2015-06-01

    Resonant Ionization Laser Ion Source (RILIS), based on the stepwise excitations of atomic transitions, offers an outstanding combination of excellent elemental selectivity and high ionization efficiency. It has become a powerful and versatile tool for generation of pure radioactive isotope beams at on-line mass separator facilities worldwide. Initiated in 2009, IPN-Orsay has installed RILIS in the Isotope Separators on-line (ISOL) system at the photofission facility ALTO, which aims to the measurements of the nuclear properties of exotic nuclei through β-γ and β-n spectroscopy, among other techniques. RILS at ALTO (RIALTO) consists of two dye lasers pumped with a 532nm 10kHz Nd:YAG laser with the wavelength extension options via frequency doubling/tripling of nonlinear crystals. Gallium and Zinc isotopic beams were successfully delivered by RIALTO starting from 2011. To develop the laser ionization scheme for different elements and test optimal operational parameters for on-line radioactive beam deliveries, an off-line reference cell has been built. The preliminary result of the first commence of the off-line reference cell will be presented in this paper.

  2. Microcracking mechanisms and interface toughening of semi-IPN polyimide matrix composites

    NASA Technical Reports Server (NTRS)

    Lee, Byung L.; Pater, R.

    1990-01-01

    A new research program was initiated as a preliminary phase. The following three objectives are being pursued for the overall program: to elucidate the mechanisms of microcracking for graphite fiber-reinforced semi-IPN polyimide matrix composites under mechanical and thermal cyclic loading; to devise material engineering solutions for possible improvement of fatigue damage resistance (or the increase of fatigue endurance strength) of semi-IPN matrix composites by tailoring of modulus and toughness of fiber-resin interface region; and to assess processing characteristics of the composites and their roles in controlling the resistance of composites to microcracking and the effectiveness of interface toughening. The main emphasis was placed upon the initial screening of material systems and optimization of processing conditions for semi-IPN matrix composites with tailored interface. As a first set of control material systems to study, the composites were prepared with unsized Celion 6000 graphite fiber reinforcement and the following resin matrices of varied fracture toughness: PMR-15 thermoset polyimide, semi-IPN of PNR-15 thermoset polyimide and NR150B2 thermoplastic polyimide in 75/25 ratio, and semi-IPN of PMR-15 and NR150B2 in 50/50 ratio. For the composites with the resin matrix of semi-IPN in 75/25 ratio, interface tailoring was attempted by using graphite fibers coated with the resins of systematically varied fracture toughness. In the continuing work, a broad range of interlayer toughness will be achieved by coating the fibers with reactants of semi-IPN having lower or higher content of thermoplastic constituent in comparison with the composition of surrounding resin matrix. In pursuing the objectives of the overall research program, the respective roles and interaction of critical parameters were defined.

  3. Risk factors for outbreaks of infectious pancreatic necrosis (IPN) and associated mortality in Norwegian salmonid farming.

    PubMed

    Bang Jensen, Britt; Kristoffersen, Anja B

    2015-06-01

    Infectious pancreatic necrosis (IPN) has for many years been considered one of the most important restraints to the production of salmonids in European aquaculture. In Norway, the disease is responsible for high losses in post-smolts in the first few weeks after sea transfer. Despite the importance of IPN, there are few epidemiological studies on risk factors and mitigation strategies. In this paper, we present analyses of data from all cohorts put to sea in 2009 to 2012 on Norwegian marine salmonid farms. The data used were obtained from national registers on salmonid production and disease outbreaks. The results showed that the risk of IPN outbreak was higher for spring versus autumn cohorts, Atlantic salmon versus rainbow trout and for cohorts on farms with previous history of IPN. The risk increased with increasing cohort size and infection pressure, whereas increasing temperature and weight at sea transfer decreased the risk. Estimations from a model of cumulative mortality within the first 6 mo after sea transfer showed that mortality in cohorts with IPN increased to approximately 7.2% as compared to a 'baseline' cohort with a mortality of 3.4%. If the cohort had both IPN and pancreas disease (PD), the estimated mortality increased to 12.9%, and cohorts with both IPN, PD and heart and skeletal muscle inflammation (HSMI) had an estimated mortality of 16.6%, when all other significant factors were kept constant (these were cohort type, year, temperature at sea transfer and weight at sea transfer). Our results provide valuable inputs for mitigation strategies and for economic modelling of consequences of disease. PMID:26036825

  4. Fabrication of chitosan/polyacrylonitrile blend and semi-IPN hydrogel with epichlorohydrin

    SciTech Connect

    Aijaz, Muhammad Omer; Haider, Sajjad Al Mubddel, Fahad S.; Al Masry, Waheed A.

    2015-05-22

    The present study is focused on the preparation of chitosan (CS)/polyacrylonitrile (PAN) blend and semi-interpenetrating polymer network (sIPN). Blend CS/PAN hydrogel films (HFs) were prepared by solution blending and casting technique. CS in the blend was crosslinked with epichlorohydrin (ECH) to prepare sIPN. The developed CS/PAN blend and sIPN hydrogels were characterized with Field Emission Scanning Electron Microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), Thermagravimetric analysis (TGA), and Differential Scanning Calorimeter (DSC). The result showed good miscibility between CS and PAN and crosslinking of CS in the blend. The swelling of the different blended and sIPN hydrogels samples were examined at room temperature (T{sub r}). Blend (C80/P20) sample showed highest swelling (∼2400%) and fair degree of stability (∼28% until 96 h), whereas sIPN hydrogel exhibited relatively low degree of swelling (∼244%) and high degree of aqueous (∼85 % until 96 h), and thermal (onset temperature 304°C) stabilities.

  5. Fabrication of chitosan/polyacrylonitrile blend and semi-IPN hydrogel with epichlorohydrin

    NASA Astrophysics Data System (ADS)

    Aijaz, Muhammad Omer; Haider, Sajjad; Al Mubddel, Fahad S.; Al Masry, Waheed. A.

    2015-05-01

    The present study is focused on the preparation of chitosan (CS)/polyacrylonitrile (PAN) blend and semi-interpenetrating polymer network (sIPN). Blend CS/PAN hydrogel films (HFs) were prepared by solution blending and casting technique. CS in the blend was crosslinked with epichlorohydrin (ECH) to prepare sIPN. The developed CS/PAN blend and sIPN hydrogels were characterized with Field Emission Scanning Electron Microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), Thermagravimetric analysis (TGA), and Differential Scanning Calorimeter (DSC). The result showed good miscibility between CS and PAN and crosslinking of CS in the blend. The swelling of the different blended and sIPN hydrogels samples were examined at room temperature (Tr). Blend (C80/P20) sample showed highest swelling (˜2400%) and fair degree of stability (˜28% until 96 h), whereas sIPN hydrogel exhibited relatively low degree of swelling (˜244%) and high degree of aqueous (˜85 % until 96 h), and thermal (onset temperature 304°C) stabilities

  6. Temperature-sensitive PVA/PNIPAAm semi-IPN hydrogels with enhanced responsive properties.

    PubMed

    Zhang, Jian-Tao; Bhat, Rahila; Jandt, Klaus D

    2009-01-01

    A series of temperature-sensitive hydrogels of semi-interpenetrating polymeric networks (semi-IPN) composed of poly(N-isopropylacrylamide) (PNIPAAm) and poly(vinyl alcohol) (PVA) were prepared by radical polymerization. The PNIPAAm networks were cross-linked by N,N'-methylenebisacrylamide in the presence of linear PVA. The reaction processes were investigated by rheometry using oscillatory deformation tests. It was found that gelations were very fast and the modulus reached equilibrium within about 12.5min. The prepared semi-IPN hydrogels were characterized for their morphologies and thermal behaviors by scanning electron microscopy and differential scanning calorimetry, respectively. The interior network structures of the semi-IPN matrix became more porous with increasing PVA. In comparison to the conventional PNIPAAm gel, the newly reported semi-IPN hydrogels exhibited the same lower critical solution temperature. Their swelling properties, such as temperature dependence of equilibrium swelling ratio, shrinking kinetics and reswelling kinetics in water, were also studied. Experimental data indicated that the shrinking and reswelling rates of the semi-IPN hydrogels were much faster than those of the conventional PNIPAAm hydrogels. With this novel approach, water absorption and response properties could be adjusted by tuning the feed ratio of NIPAAm and PVA. These fast responsive hydrogels exhibited improved temperature sensitivity and swelling properties compared to the conventional PNIPAAm hydrogel, which would be critical and desirable for a gel to find potential applications in biomedical fields, such as drug delivery systems and sensors. PMID:18656431

  7. Real-time SANS study of interpenetrating polymer network (IPN) formation

    NASA Astrophysics Data System (ADS)

    Burford, Robert P.; Markotsis, Martin G.; Knott, Robert B.

    2006-11-01

    Interpenetrating polymer networks (IPNs) are a combination of two or more polymers in network form, with at least one polymer polymerised and/or crosslinked. The nanostructure was investigated for sequential IPNs formed from (i) either radial or linear poly(styrene-co-butadiene-co-styrene) (SB 4/SBS) copolymer, and (ii) polystyrene (PS). For polymer network I, the SB 4/SBS copolymer self-assembled into ordered micro-domain structures, which acted as a template for the resultant IPN. The formation of the IPN was studied using real-time small angle neutron scattering. For the linear SBS IPN, the time-zero pattern showed an ordered lamella structure and as polymerisation and crosslinking progressed, the first-order peak increased in amplitude (factor ×4) and higher-order peaks appeared. The position and width of the first-order peak did not change significantly, indicating that the size and spacing of the domains did not change. The increase in molecular organisation can be attributed to (i) sharpening of phase boundaries, (ii) annealing of domain positions, and/or (iii) increasing the contrast by material moving between domains. Investigations of phase transformation kinetics may aid in the design of specific structures for nanotechnology applications, as well as traditional engineering applications.

  8. How-to-Do-It. Fast Plants--Rapid-Cycling Brassicas.

    ERIC Educational Resources Information Center

    Hafner, Robert

    1990-01-01

    Described is an activity in which the life cycle of a plant is investigated over a 20-day period. Included are background information, a list of materials, procedures, diagrams of the plant, apparatus, and pollination. An outline is suggested. (CW)

  9. Electron-proton instability in the IPNS-Upgrade RCS: Part I

    SciTech Connect

    Chae, Yong-Chul

    1995-02-27

    The electron-proton instability in the IPNS-Upgrade RCS is investigated in this report. A dispersion relation applicable to the coasting beam is derived, and the approximations used are stated in order to facilitate the understanding of the underlying mechanism of the instability. The threshold of instability in terms of neutralization of the circulating beam is found for the IPNS-Upgrade RCS. The dependence of threshold on the beam size and the lattice tune is also studied and its numerical results are presented.

  10. Justification of rapid prototyping in the development cycle of thermoplastic-based lab-on-a-chip.

    PubMed

    Preywisch, Regina; Ritzi-Lehnert, Marion; Drese, Klaus S; Röser, Tina

    2011-11-01

    During the developmental cycle of lab-on-a-chip devices, various microstructuring techniques are required. While in the designing and assay implementation phase direct structuring or so-called rapid-prototyping methods such as milling or laser ablation are applied, replication methods like hot embossing or injection moulding are favourable for large quantity manufacturing. This work investigated the applicability of rapid-prototyping techniques for thermoplastic chip development in general, and the reproducibility of performances in dependency of the structuring technique. A previously published chip for prenatal diagnosis that preconcentrates DNA via electrokinetic trapping and field-amplified-sample-stacking and afterwards separates it in CGE was chosen as a model. The impact of structuring, sealing, and the integration of membranes on the mobility of the EOF, DNA preconcentration, and DNA separation was studied. Structuring methods were found to significantly change the location where preconcentration of DNA occurs. However, effects on the mobility of the EOF and the separation quality of DNA were not observed. Exchange of the membrane has no effect on the chip performance, whereas the sealing method impairs the separation of DNA within the chip. The overall assay performance is not significantly influenced by different structuring methods; thus, the application of rapid-prototyping methods during a chip development cycle is well justified. PMID:22102495

  11. Effect of five cycle rapid freeze-thaw treatment in conjunction with various chemicals for the reduction of Salmonella typhimurium.

    PubMed

    Olson, V M; Swaminathan, B; Pratt, D E; Stadelman, W J

    1981-08-01

    A five cycle rapid freeze-rapid thaw process was used in conjunction with chemicals to reduce numbers of Salmonella typhimurium cells on poultry meat. The second portion of chicken wings consisting of ulna and radius with attached skin and muscle was inoculated with 400 to 900 colony forming units (CFU/g) of a nalidixic acid resistant strain of S. typhimurium. Chemicals used were 20 ppm chlorine, 5% potassium sorbate, 5% lactic acid, and 5% calcium propionate. The wings were either sprayed with or dipped into all chemicals before the freeze-thaw process. Wings were also chemically treated and not subjected to the freeze-thaw process. Numbers of S. typhimurium were determined by the most probable number procedure. The relative effectiveness of combinations of chemicals and the freeze-thaw process was compared to a control with the following percentage reductions of numbers of S. typhimurium cells: lactic acid, 98%; calcium propionate, 96%; potassium sorbate, 96%; chlorine, 95%; and freeze-thaw process without chemicals, 95%. There were no statistically significant differences among the treatments. In pilot plant study simulating commercial conditions, a carbon dioxide freezer was used for the rapid freeze and a microwave oven was used for the rapid thaw. Treatment of wings with 5% lactic acid plus freeze-thaw process resulted in statistically significant fewer numbers of S. typhimurium cells when compared to the freeze-thaw process without chemical treatment or to wings chemically treated without the freeze-thaw process. PMID:7322982

  12. 3D noninvasive, high-resolution imaging using a photoacoustic tomography (PAT) system and rapid wavelength-cycling lasers

    NASA Astrophysics Data System (ADS)

    Sampathkumar, Ashwin; Gross, Daniel; Klosner, Marc; Chan, Gary; Wu, Chunbai; Heller, Donald F.

    2015-05-01

    Globally, cancer is a major health issue as advances in modern medicine continue to extend the human life span. Breast cancer ranks second as a cause of cancer death in women in the United States. Photoacoustic (PA) imaging (PAI) provides high molecular contrast at greater depths in tissue without the use of ionizing radiation. In this work, we describe the development of a PA tomography (PAT) system and a rapid wavelength-cycling Alexandrite laser designed for clinical PAI applications. The laser produces 450 mJ/pulse at 25 Hz to illuminate the entire breast, which eliminates the need to scan the laser source. Wavelength cycling provides a pulse sequence in which the output wavelength repeatedly alternates between 755 nm and 797 nm rapidly within milliseconds. We present imaging results of breast phantoms with inclusions of different sizes at varying depths, obtained with this laser source, a 5-MHz 128-element transducer and a 128-channel Verasonics system. Results include PA images and 3D reconstruction of the breast phantom at 755 and 797 nm, delineating the inclusions that mimic tumors in the breast.

  13. Mapping the Anthocyaninless (anl) Locus in Rapid-Cycling Brassica rapa (RBr) to Linkage Group R9

    PubMed Central

    Burdzinski, Carrie; Wendell, Douglas L

    2007-01-01

    Background Anthocyanins are flavonoid pigments that are responsible for purple coloration in the stems and leaves of a variety of plant species. Anthocyaninless (anl) mutants of Brassica rapa fail to produce anthocyanin pigments. In rapid-cycling Brassica rapa, also known as Wisconsin Fast Plants, the anthocyaninless trait, also called non-purple stem, is widely used as a model recessive trait for teaching genetics. Although anthocyanin genes have been mapped in other plants such as Arabidopsis thaliana, the anl locus has not been mapped in any Brassica species. Results We tested primer pairs known to amplify microsatellites in Brassicas and identified 37 that amplified a product in rapid-cycling Brassica rapa. We then developed three-generation pedigrees to assess linkage between the microsatellite markers and anl. 22 of the markers that we tested were polymorphic in our crosses. Based on 177 F2 offspring, we identified three markers linked to anl with LOD scores ≥ 5.0, forming a linkage group spanning 46.9 cM. Because one of these markers has been assigned to a known B. rapa linkage group, we can now assign the anl locus to B. rapa linkage group R9. Conclusion This study is the first to identify the chromosomal location of an anthocyanin pigment gene among the Brassicas. It also connects a classical mutant frequently used in genetics education with molecular markers and a known chromosomal location. PMID:17894874

  14. Contrail life cycle and properties from 1 year of MSG/SEVIRI rapid-scan images

    NASA Astrophysics Data System (ADS)

    Vázquez-Navarro, M.; Mannstein, H.; Kox, S.

    2015-08-01

    The automatic contrail tracking algorithm (ACTA) - developed to automatically follow contrails as they age, drift and spread - enables the study of a large number of contrails and the evolution of contrail properties with time. In this paper we present a year's worth of tracked contrails, from August 2008 to July 2009 in order to derive statistically significant mean values. The tracking is performed using the 5 min rapid-scan mode of the Spinning Enhanced Visible and Infrared Imager (SEVIRI) on board the Meteosat Second Generation (MSG) satellites. The detection is based on the high spatial resolution of the images provided by the Moderate Resolution Imaging Spectroradiometer on board the Terra satellite (Terra/MODIS), where a contrail detection algorithm (CDA) is applied. The results show the satellite-derived average lifetimes of contrails and contrail-cirrus along with the probability density function (PDF) of other geometric characteristics such as mean coverage, distribution and width. In combination with specifically developed algorithms (RRUMS; Rapid Retrieval of Upwelling irradiance from MSG/SEVIRI and COCS (Cirrus Optical properties derived from CALIOP and SEVIRI), explained below) it is possible to derive the radiative forcing (RF), energy forcing (EF), optical thickness (τ) and altitude of the tracked contrails. Mean values here retrieved are duration, 1 h; length, 130 km; width, 8 km; altitude, 11.7 km; optical thickness, 0.34. Radiative forcing and energy forcing are shown for land/water backgrounds in day/night situations.

  15. Contrail life cycle and properties from one year of MSG/SEVIRI rapid-scan images

    NASA Astrophysics Data System (ADS)

    Vázquez-Navarro, M.; Mannstein, H.; Kox, S.

    2015-03-01

    The Automatic Contrail Tracking Algorithm (ACTA) -developed to automatically follow contrails as they age, drift and spread- enables the study of a large number of contrails and the evolution of contrail properties with time. In this paper we present a year's worth of tracked contrails, from August 2008 to July 2009 in order to derive statistically significant mean values. The tracking is performed using the 5 min rapid-scan mode of the Spinning Enhanced Visible and Infrared Imager (SEVIRI) on board of the Meteosat Second Generation satellites (MSG). The detection is based on the high spatial resolution of the images provided by the Moderate Resolution Imaging Spectroradiometer on board of the Terra satellite (Terra/MODIS), where a Contrail Detection Algorithm (CDA) is applied. The results show the satellite-derived average lifetimes of contrails and contrail-cirrus along with the probability density function (PDF) of other geometric characteristics such as mean coverage, distribution and width. In combination with specifically developed algorithms (RRUMS and COCS, explained below) it is possible to derive the radiative forcing (RF), energy forcing (EF), optical thickness (τ), and altitude of the tracked contrails. Mean values here retrieved are: duration, 1 h; length, 130 km; width, 8 km; altitude, 11.7 km; optical thickness, 0.34. Radiative forcing and energy forcing are shown for land/water backgrounds in day/night situations.

  16. Maintaining Adequate CO2 Washout for an Advanced EMU via a New Rapid Cycle Amine Technology

    NASA Technical Reports Server (NTRS)

    Chullen, Cinda

    2011-01-01

    Over the past several years, NASA has realized tremendous progress in Extravehicular Activity (EVA) technology development. This has been evidenced by the progressive development of a new Rapic Cycle Amine (RCA) system for the Advanced Extravehicular Mobility Unit (AEMU) Portable Life Support Subsystem (PLSS). The PLSS is responsible for the life support of the crew member in the spacesuit. The RCA technology is responsible for carbon dioxide (CO2) and humidity control. Another aspect of the RCA is that it is on-back vacuum-regenerable, efficient, and reliable. The RCA also simplifies the PLSS schematic by eliminating the need for a condensing heat exchanger for humidity control in the current EMU. As development progresses on the RCA, it is important that the sizing be optimized so that the demand on the PLSS battery is minimized. As well, maintaining the CO2 washout at adequate levels during an EVA is an absolute requirement of the RCA and associated ventilation system. Testing has been underway in-house at NASA Johnson Space Center and analysis has been initiated to evaluate whether the technology provides exemplary performance in ensuring that the CO2 is removed sufficiently enough and the ventilation flow is adequate enough to maintain CO2 1 Project Engineer, Space Suit and Crew Survival Systems Branch, Crew and Thermal Systems Division, 2101 NASA Parkway, Houston, TX 77058/EC5. washout in the AEMU spacesuit helmet of the crew member during an EVA. This paper will review the recent developments of the RCA unit, the testing results performed in-house with a spacesuit simulator, and the associated analytical work along with insights from the medical aspect on the testing.

  17. Dietary Deficiency of Essential Amino Acids Rapidly Induces Cessation of the Rat Estrous Cycle

    PubMed Central

    Bannai, Makoto; Ichimaru, Toru; Nakano, Sayako; Murata, Takuya; Higuchi, Takashi; Takahashi, Michio

    2011-01-01

    Reproductive functions are regulated by the sophisticated coordination between the neuronal and endocrine systems and are sustained by a proper nutritional environment. Female reproductive function is vulnerable to effects from dietary restrictions, suggesting a transient adaptation that prioritizes individual survival over reproduction until a possible future opportunity for satiation. This adaptation could also partially explain the existence of amenorrhea in women with anorexia nervosa. Because amino acid nutritional conditions other than caloric restriction uniquely alters amino acid metabolism and affect the hormonal levels of organisms, we hypothesized that the supply of essential amino acids in the diet plays a pivotal role in the maintenance of the female reproductive system. To test this hypothesis, we examined ovulatory cyclicity in female rats under diets that were deficient in threonine, lysine, tryptophan, methionine or valine. Ovulatory cyclicity was monitored by daily cytological evaluations of vaginal smears. After continuous feeding of the deficient diet, a persistent diestrus or anovulatory state was induced most quickly by the valine-deficient diet and most slowly by the lysine-deficient diet. A decline in the systemic insulin-like growth factor 1 level was associated with a dietary amino acid deficiency. Furthermore, a paired group of rats that were fed an isocaloric diet with balanced amino acids maintained normal estrous cyclicity. These disturbances of the estrous cycle by amino acid deficiency were quickly reversed by the consumption of a normal diet. The continuous anovulatory state in this study is not attributable to a decrease in caloric intake but to an imbalance in the dietary amino acid composition. With a shortage of well-balanced amino acid sources, reproduction becomes risky for both the mother and the fetus. It could be viewed as an adaptation to the diet, diverting resources away from reproduction and reallocating them to

  18. Anti-AMPA-Receptor Encephalitis Presenting as a Rapid-Cycling Bipolar Disorder in a Young Woman with Turner Syndrome

    PubMed Central

    Quaranta, Giuseppe; Maremmani, Angelo Giovanni Icro; Perugi, Giulio

    2015-01-01

    Background. Autoimmune encephalitis is a disorder characterised by the subacute onset of seizures, short-term memory loss, and psychiatric and behavioural symptoms. Initially, it was recognised as a paraneoplastic disorder, but recently a subgroup of patients without systemic cancer was identified. Case Description. We describe a 20-year-old woman with Turner syndrome presenting with a treatment-resistant rapid cycling bipolar disorder with cognitive impairment. She was diagnosed with anti-AMPA-receptor encephalitis. She showed marked improvement after starting memantine and valproic acid. Conclusion. This case description emphasises the importance of timely recognition of autoimmune limbic encephalitis in patients with psychiatric manifestations and a possible predisposition to autoimmune conditions, in order to rule out malignancy and to quickly initiate treatment. PMID:26495149

  19. Identification of pathogenic Leptospira genospecies by continuous monitoring of fluorogenic hybridization probes during rapid-cycle PCR.

    PubMed Central

    Woo, T H; Patel, B K; Smythe, L D; Symonds, M L; Norris, M A; Dohnt, M F

    1997-01-01

    Partial sequences of 23S rRNA gene PCR products from 23 strains of 6 pathogenic Leptospira genospecies and from 8 strains of the saprophytic Leptospira biflexa were determined. Sequence analyses enabled Leptospira genus-specific amplification primers and pathogen-specific fluorogenic adjacent hybridization probes to be designed and synthesized. A PCR protocol was developed in which changes in fluorescence emission resulting from specific annealing of fluorogenic adjacent hybridization probes to the target DNA were continuously monitored. Nine strains of the pathogenic Leptospira genospecies could be differentiated from Leptonema illini, Escherichia coli, and eight strains of Leptospira biflexa. The PCR method was rapid, requiring 18 min for the completion of 45 cycles. It was also simple and flexible, as DNA templates prepared by four different methods, including the simple boiling method, could be used without adverse effects. Two hundred copies of target, equivalent to 100 cells, could be detected. PMID:9399509

  20. Impedance measurements of the extraction kicker system for the rapid cycling synchrotron of China Spallation Neutron Source

    NASA Astrophysics Data System (ADS)

    Huang, Liang-Sheng; Wang, Sheng; Liu, Yu-Dong; Li, Yong; Liu, Ren-Hong; Xiao, Ou-Zheng

    2016-04-01

    The fast extraction kicker system is one of the most important accelerator components and the main source of impedance in the Rapid Cycling Synchrotron of the China Spallation Neutron Source. It is necessary to understand the kicker impedance before its installation into the tunnel. Conventional and improved wire methods are employed in the impedance measurement. The experimental results for the kicker impedance are explained by comparison with simulation using CST PARTICLE STUDIO. The simulation and measurement results confirm that the window-frame ferrite geometry and the end plate are the important structures causing coupling impedance. It is proved in the measurements that the mismatching from the power form network to the kicker leads to a serious oscillation sideband of the longitudinal and vertical impedance and the oscillation can be reduced by ferrite absorbing material. Supported by National Natural Science Foundation of China (11175193, 11275221)

  1. Breakage-fusion-bridge Cycles and Large Insertions Contribute to the Rapid Evolution of Accessory Chromosomes in a Fungal Pathogen

    PubMed Central

    Croll, Daniel; Zala, Marcello; McDonald, Bruce A.

    2013-01-01

    Chromosomal rearrangements are a major driver of eukaryotic genome evolution, affecting speciation, pathogenicity and cancer progression. Changes in chromosome structure are often initiated by mis-repair of double-strand breaks in the DNA. Mis-repair is particularly likely when telomeres are lost or when dispersed repeats misalign during crossing-over. Fungi carry highly polymorphic chromosomal complements showing substantial variation in chromosome length and number. The mechanisms driving chromosome polymorphism in fungi are poorly understood. We aimed to identify mechanisms of chromosomal rearrangements in the fungal wheat pathogen Zymoseptoria tritici. We combined population genomic resequencing and chromosomal segment PCR assays with electrophoretic karyotyping and resequencing of parents and offspring from experimental crosses to show that this pathogen harbors a highly diverse complement of accessory chromosomes that exhibits strong global geographic differentiation in numbers and lengths of chromosomes. Homologous chromosomes carried highly differentiated gene contents due to numerous insertions and deletions. The largest accessory chromosome recently doubled in length through insertions totaling 380 kb. Based on comparative genomics, we identified the precise breakpoint locations of these insertions. Nondisjunction during meiosis led to chromosome losses in progeny of three different crosses. We showed that a new accessory chromosome emerged in two viable offspring through a fusion between sister chromatids. Such chromosome fusion is likely to initiate a breakage-fusion-bridge (BFB) cycle that can rapidly degenerate chromosomal structure. We suggest that the accessory chromosomes of Z. tritici originated mainly from ancient core chromosomes through a degeneration process that included BFB cycles, nondisjunction and mutational decay of duplicated sequences. The rapidly evolving accessory chromosome complement may serve as a cradle for adaptive evolution in

  2. On the Development of Thermally Stable Semi-IPNs of PVA and PAN using IR, DSC and XRD Studies

    NASA Astrophysics Data System (ADS)

    Deshpande, Deepti S.; Bajpai, R.; Bajpai, A. K.

    2011-07-01

    A novel biopolymer based Semi-IPN of polyvinyl alcohol (PVA) and polycrylonitrile (PAN) were synthesized in various proportions by redox polymerization and analyzed thermally by differential scanning calorimetry (DSC). DSC thermograms shows good thermal stability, as a result of incorporation of acrylonitrile as the second network. The structural and morphological study of these semi-IPNs by FTIR and XRD technique, respectively, were correlated. The approach seems to be beneficial for various biomedical applications.

  3. Comparative bio-safety and in vivo evaluation of native or modified locust bean gum-PVA IPN microspheres.

    PubMed

    Kaity, Santanu; Ghosh, Animesh

    2015-01-01

    Strategically developed natural polymer-based controlled release multiparticulate drug delivery systems have gained special interest for “spatial placement” and “temporal delivery” of drug molecules. In our earlier study, locust bean gum-poly(vinyl alcohol) interpenetrating polymer network (LBG-PVA IPN), carboxymethylated locust bean gum-poly(vinyl alcohol) interpenetrating polymer network (CMLBG-PVA IPN) and acrylamide grafted locust bean gum-poly(vinyl alcohol) interpenetrating polymer network (Am-g-LBG-PVA IPN) were prepared and characterized. The present study deals with accelerating stability testing, comparative bio-safety and single dose in vivo pharmacokinetic study of all three IPN microspheres for controlled oral delivery of buflomedil hydrochloride (BH). From the stability study, it was observed that the particles were stable throughout the study period. From toxicity and biodegradability study it was proved that the microspheres were safe for internal use and complied with bio-safety criterion. From the in vivo pharmacokinetic study in rabbits, it was observed that the CMLBG-PVA IPN microspheres possessed almost similar Tmax value with BH oral suspension. However, in comparison between the LBG-PVA and Am-g-LBG-PVA IPN microspheres, the later showed well controlled release property than the first in biological condition. Thus, this type of delivery system might be useful to achieve the lofty goals of the controlled release drug delivery. PMID:25307127

  4. Evaluation of structural integrity of IPNS-I and ZING-P' targets

    SciTech Connect

    Carpenter, J.; Ahmed, H.; Loomis, B.; Ball, J.; Ewing, T.; Bailey, J.; D'Souza, A.F.

    1982-12-01

    This report discusses the design, production, and evaluation of clad uranium-alloy targets that function as spallation neutron sources in the ZING-P' and IPNS-I facilities with a pulsed (10 to 30 Hz), 500-MeV proton beam. The methodology and results of theoretical nuclear-particle transport, heat transport, and stress analyses that were used in the development of a design for the targets are described. The production of a zirconium-clad uranium-alloy cylinder for ZING-P' and Zircaloy-2-clad uranium-alloy discs for IPNS-I is discussed with particular attention to the procedural details. The theoretical analyses were verified by measuring the thermal and mechanical response of the clad uranium under conditions designed to simulate the operations of the pulsed-neutron sources.

  5. Creep and recovery behaviors of magnetorheological elastomer based on polyurethane/epoxy resin IPNs matrix

    NASA Astrophysics Data System (ADS)

    Qi, S.; Yu, M.; Fu, J.; Li, P. D.; Zhu, M.

    2016-01-01

    This paper mainly investigated the creep and recovery behaviors of magnetorheological elastomers (MRE) based on polyurethane/epoxy resin (EP) graft interpenetrating polymer networks (IPNs). The influences of constant stress level, content of EP, particle distribution, magnetic field and temperature on the creep and recovery behaviors were systematically investigated. As expected, results suggested that the presence of IPNs leads to a significant improvement of creep resistance of MRE, and creep and recovery behaviors of MRE were highly dependent on magnetic field and temperature. To further understand its deformation mechanism, several models (i.e., Findley’s power law model, Burgers model, and Weibull distribution equation) were used to fit the measured creep and recovery data. Results showed that the modeling of creep and recovery of samples was satisfactorily conducted by using these models. The influences of content of EP and magnetic field on fitting parameters were discussed, and relevant physical mechanism was proposed to explain it qualitatively.

  6. Chemical semi-IPN hydrogels for the removal of adhesives from canvas paintings

    NASA Astrophysics Data System (ADS)

    Domingues, Joana; Bonelli, Nicole; Giorgi, Rodorico; Baglioni, Piero

    2014-03-01

    Semi-interpenetrating (IPN) poly (2-hydroxyethyl methacrylate)/polyvinylpyrrolidone hydrogels were synthesized and used for the removal of adhesives from the back of canvas paintings. The high water retention capability and the specific mechanical properties of these gels allow the safe cleaning of water-sensitive artifacts using water-based detergent systems. The cleaning action is limited to the contact area and layer-by-layer removal is achieved while avoiding water spreading and absorption within water-sensitive substrates, which could lead, for example, to paint detachment. The use of these chemical gels also avoids leaving residues over the treated surface because the gel network is formed by covalent bonds that provide high mechanical strength. In this contribution, the physicochemical characterization of semi-IPN chemical hydrogels is reported. The successful application of an o/w microemulsion confined in the hydrogel for the removal of adhesives from linen canvas is also illustrated.

  7. Radio and Optical Follow-Up Observations and Improved IPN Position of GRB 970111

    NASA Technical Reports Server (NTRS)

    Galama, T. J.; Groot, P. J.; Strom, R. G.; vanParadijs, J.; Hurley, K.; Kouveliotou, C.; Fishman, G. J.; Meegan, C. A.; Heise, J.; intZand, J. J. M.

    1997-01-01

    We report on Westerbork 840 MHz, 1.4 and 5 GHz radio observations of the improved IPN-WFC error box of the gamma ray burst GRB 970111, between 26.4 hours and 120 days after the event onset. In the approximately 16 sq arcmin area defined by the IPN (BATSE and Ulysses) annulus and the published refined BeppoSAX Wide Field Camera (WFC) error box we detected no steady sources brighter than 0.56 mJy (4sigma), and no varying radio emission, down to 1.0 mJy (4sigma). We also report on B, V, R and I band observations of the error box with the 4.2 m William Herschel Telescope at La Palma. Subject headings: gamma rays: bursts - gamma rays: individual (GRB 9701 1 1)

  8. GRB 080407: An Ultra-long Burst Discovered by the IPN

    NASA Technical Reports Server (NTRS)

    Cummings, J; Barthelmy, S.; Gehrels, N.; Krimm, H.; Palmer, D.; Palshin, V.; Hurley, K.; Goldsten, J.; Mitrofanov, I. G.; Boynton, W.; vonKienlln, A.; Feroci, M.; Aptekar, R.; Frederiks, D.; Golenetskli, S.; Mazets, E.; Svinkin, D.; Golovin, D.; Litvak, M. L.; Sanin, A. B.; Fellows, C.; Harshman, K.; Starr, R.; Rau, A.; Zhang, X.

    2012-01-01

    We present observations of the extremely long GRB 080704 obtained with the instruments of the Interplanetary Network (IPN). The observations reveal two distinct emission episodes, separated by a approx.1500 s long period of quiescence. The total burst duration is about 2100 s. We compare the temporal and spectral characteristics of this burst with those obtained for other ultra-long GRBs and discuss these characteristics in the context of different models.

  9. Rapid changes in the seasonal sea level cycle along the US Gulf coast in the early 21st century

    NASA Astrophysics Data System (ADS)

    Wahl, T.; Calafat, F. M.; Luther, M. E.

    2013-12-01

    annual amplitude and the rapid increase over the last decade in the eastern GOM. We have developed several multiple regression models (MRM) with a varying number of independent predictors to reconstruct the temporal changes back to the mid and early 20th century (depending on data availability of the predictors). The models are able to explain up to 85% of the observed variability (70% on average across sites) and major parts of the rapid increase in the early 21st century. Multicollinearity between the predictors makes it difficult to quantify the contribution of individual parameters to the increase but sensitivity tests outline that changes in the annual cycle of the air surface temperature (which in turn directly propagates into the sea surface temperature) played a dominant role. The MRMs allow us to reconstruct the seasonal sea level cycle back to the early 20th century at all tide gauge sites and will be used in a follow-up study in combination with regional climate model output to assess potential future changes.

  10. Characterization and swelling-deswelling properties of wheat straw cellulose based semi-IPNs hydrogel.

    PubMed

    Liu, Jia; Li, Qian; Su, Yuan; Yue, Qinyan; Gao, Baoyu

    2014-07-17

    A novel wheat straw cellulose-g-poly(potassium acrylate)/polyvinyl alcohol (WSC-g-PKA/PVA) semi-interpenetrating polymer networks (semi-IPNs) hydrogel was prepared by polymerizing wheat straw and an aqueous solution of acrylic acid (AA), and further semi-interpenetrating with PVA occurred during the chemosynthesis. The swelling and deswelling properties of WSC-g-PKA/PVA semi-IPNs hydrogel and WSC-g-PKA hydrogel were studied and compared in various pH solutions, salt solutions, temperatures, particle sizes and ionic strength. The results indicated that both hydrogels had the largest swelling capacity at pH=6, and the effect of ions on the swelling of hydrogels was in the order: Na(+)>K(+)>Mg(2+)>Ca(2+). The Schott's pseudo second order model can be effectively used to evaluate swelling kinetics of hydrogels. Moreover, the semi-IPNs hydrogel had improved swelling-deswelling properties compared with that of WSC-g-PKA hydrogel. PMID:24702940

  11. Calcium alginate/dextran methacrylate IPN beads as protecting carriers for protein delivery.

    PubMed

    D'Arrigo, Giorgia; Di Meo, Chiara; Pescosolido, Laura; Coviello, Tommasina; Alhaique, Franco; Matricardi, Pietro

    2012-07-01

    In the present study, mechanical and protein delivery properties of a system based on the interpenetration of calcium-alginate (Ca-Alg) and dextran-methacrylate (Dex-MA) networks are shown. Interpenetrated hydrogels beads were prepared by means of the alginate chains crosslinking with calcium ions, followed by the exposure to UV light that allows the Dex-MA network formation. Optical microscope analysis showed an average diameter of the IPN beads (Ca-Alg/Dex-MA) of 2 mm. This dimension was smaller than that of Ca-Alg beads because of the Dex-MA presence. Moreover, the strength of the IPN beads, and of their corresponding hydrogels, was influenced by the Dex-MA concentration and the crosslinking time. Model proteins (BSA and HRP) were successfully entrapped into the beads and released at a controlled rate, modulated by changing the Dex-MA concentration. The enzymatic activity of HRP released from the beads was maintained. These novel IPN beads have great potential as protein delivery system. PMID:22528076

  12. Biodegradable IPN hydrogel beads of pectin and grafted alginate for controlled delivery of diclofenac sodium.

    PubMed

    Giri, Tapan Kumar; Thakur, Deepa; Alexander, Amit; Ajazuddin; Badwaik, Hemant; Tripathy, Minaketan; Tripathi, Dulal Krishna

    2013-05-01

    A novel diclofenac sodium (DS) loaded interpenetrating polymer network (IPN) beads of pectin and hydrolyzed polyacrylamide-graft-sodium alginate (PAAm-g-SA) was developed through ionotropic gelation and covalent cross-linking. The graft copolymer was synthesized by free radical polymerization under the nitrogen atmosphere followed by alkaline hydrolysis. The grafting, alkaline hydrolysis, and characterization of beads were confirmed by Fourier transforms infrared spectroscopy. The crystalline structure of drug after encapsulation into IPN beads were evaluated by differential scanning colorimetry and X-ray diffraction analyses. DS encapsulation was up to 96.45 %. The effect of hydrolyzed graft copolymer/pectin ratios and glutaraldehyde concentration on drug release in acidic and phosphate buffer solutions were investigated. The release of drug was significantly increased with increase of pH. The release of drug depends on the extent of cross-linking. The results indicated that IPN beads of hydrolyzed PAAm-g-SA and pectin could be used for sustained release of DS. PMID:23423649

  13. Mining Available Data from the United States Environmental Protection Agency to Support Rapid Life Cycle Inventory Modeling of Chemical Manufacturing.

    PubMed

    Cashman, Sarah A; Meyer, David E; Edelen, Ashley N; Ingwersen, Wesley W; Abraham, John P; Barrett, William M; Gonzalez, Michael A; Randall, Paul M; Ruiz-Mercado, Gerardo; Smith, Raymond L

    2016-09-01

    Demands for quick and accurate life cycle assessments create a need for methods to rapidly generate reliable life cycle inventories (LCI). Data mining is a suitable tool for this purpose, especially given the large amount of available governmental data. These data are typically applied to LCIs on a case-by-case basis. As linked open data becomes more prevalent, it may be possible to automate LCI using data mining by establishing a reproducible approach for identifying, extracting, and processing the data. This work proposes a method for standardizing and eventually automating the discovery and use of publicly available data at the United States Environmental Protection Agency for chemical-manufacturing LCI. The method is developed using a case study of acetic acid. The data quality and gap analyses for the generated inventory found that the selected data sources can provide information with equal or better reliability and representativeness on air, water, hazardous waste, on-site energy usage, and production volumes but with key data gaps including material inputs, water usage, purchased electricity, and transportation requirements. A comparison of the generated LCI with existing data revealed that the data mining inventory is in reasonable agreement with existing data and may provide a more-comprehensive inventory of air emissions and water discharges. The case study highlighted challenges for current data management practices that must be overcome to successfully automate the method using semantic technology. Benefits of the method are that the openly available data can be compiled in a standardized and transparent approach that supports potential automation with flexibility to incorporate new data sources as needed. PMID:27517866

  14. Using chondroitin sulfate to improve the viability and biosynthesis of chondrocytes encapsulated in interpenetrating network (IPN) hydrogels of agarose and poly(ethylene glycol) diacrylate.

    PubMed

    Ingavle, Ganesh C; Dormer, Nathan H; Gehrke, Stevin H; Detamore, Michael S

    2012-01-01

    We recently introduced agarose-poly(ethylene glycol) diacrylate (PEGDA) interpenetrating network (IPN) hydrogels to cartilage tissue engineering that were able to encapsulate viable cells and provide a significant improvement in mechanical performance relative to its two constituent hydrogels. The goal of the current study was to develop a novel synthesis protocol to incorporate methacrylated chondroitin sulfate (MCS) into the IPN design hypothesized to improve cell viability and biosynthesis. The IPN was formed by encapsulating porcine chondrocytes in agarose, soaking the construct in a solution of 1:10 MCS:PEGDA, which was then photopolymerized to form a copolymer network as the second network. The IPN with incorporated CS (CS-IPN) (~0.5 wt%) resulted in a 4- to 5-fold increase in the compressive elastic modulus relative to either the PEGDA or agarose gels. After 6 weeks of in vitro culture, more than 50% of the encapsulated chondrocytes remained viable within the CS-modified IPN, in contrast to 35% viability observed in the unmodified. At week 6, the CS-IPN had significantly higher normalized GAG contents (347 ± 34 μg/μg) than unmodified IPNs (158 ± 27 μg/μg, P < 0.05). Overall, the approach of incorporating biopolymers such as CS from native tissue may provide favorable micro-environment and beneficial signals to cells to enhance their overall performance in IPNs. PMID:22116661

  15. Progress on the IPNS Enriched Uranium Booster Target

    SciTech Connect

    Knox, A E; Carpenter, J M; Bailey, J L; Armani, R J; Blomquist, R N; Brown, B S; Henley, D R; Hins, A G; Loomis, B A; Schulke, A W

    1986-09-01

    We describe the Enriched Uranium Booster Target designed for use in Argonne's Intense Pulsed Neutron Source. This report contains a general description of the system, and descriptions of the thermal-hydraulic and loss-of-coolant accident analyses, of the neutronic, criticality and power density calculations, of the assessment of radiation and thermal cycling growth, and of the disk fabrication methods. We also describe the calculations of radionuclide buildup and the related hazards analysis and our calculations of the temperature and stress profiles in the disks, and briefly allude to considerations of security and safeguards.

  16. Rapid freeze-drying cycle optimization using computer programs developed based on heat and mass transfer models and facilitated by tunable diode laser absorption spectroscopy (TDLAS).

    PubMed

    Kuu, Wei Y; Nail, Steven L

    2009-09-01

    Computer programs in FORTRAN were developed to rapidly determine the optimal shelf temperature, T(f), and chamber pressure, P(c), to achieve the shortest primary drying time. The constraint for the optimization is to ensure that the product temperature profile, T(b), is below the target temperature, T(target). Five percent mannitol was chosen as the model formulation. After obtaining the optimal sets of T(f) and P(c), each cycle was assigned with a cycle rank number in terms of the length of drying time. Further optimization was achieved by dividing the drying time into a series of ramping steps for T(f), in a cascading manner (termed the cascading T(f) cycle), to further shorten the cycle time. For the purpose of demonstrating the validity of the optimized T(f) and P(c), four cycles with different predicted lengths of drying time, along with the cascading T(f) cycle, were chosen for experimental cycle runs. Tunable diode laser absorption spectroscopy (TDLAS) was used to continuously measure the sublimation rate. As predicted, maximum product temperatures were controlled slightly below the target temperature of -25 degrees C, and the cascading T(f)-ramping cycle is the most efficient cycle design. In addition, the experimental cycle rank order closely matches with that determined by modeling. PMID:19504575

  17. Assimilation of GOES Land Surface Data Within a Rapid Update Cycle Format: Impact on MM5 Warm Season QPF

    NASA Technical Reports Server (NTRS)

    Lapenta, William M.; Suggs, Ron; Jedlovec, Gary; McNider, Richard T.; Dembek, Scott; Arnold, James E. (Technical Monitor)

    2001-01-01

    A technique has been developed for assimilating GOES-derived skin temperature tendencies and insolation into the surface energy budget equation of a mesoscale model so that the simulated rate of temperature change closely agrees with the satellite observations. A critical assumption of the technique is that the availability of moisture (either from the soil or vegetation) is the least known term in the model's surface energy budget. Therefore, the simulated latent heat flux, which is a function of surface moisture availability, is adjusted based upon differences between the modeled and satellite-observed skin temperature tendencies. An advantage of this technique is that satellite temperature tendencies are assimilated in an energetically consistent manner that avoids energy imbalances and surface stability problems that arise from direct assimilation of surface shelter temperatures. The fact that the rate of change of the satellite skin temperature is used rather than the absolute temperature means that sensor calibration is not as critical. The focus of this paper is to examine how the satellite assimilation technique impacts simulations of near-surface meteorology on the 0-to 12-hour time scale when implemented within a local rapid update cycle (LRUC) format. The PSU/NCAR MM5 V34 is used and configured with a 36-km CONUS domain and a 12-km nest centered over the southeastern US. The LRUC format consists of a sequence of 12-hour forecasts initialized every hour between 12 and 18 UTC seven days a week. GOES skin temperature tendencies and solar insolation are assimilated in a 1-hour period prior to the start of each twelve-hour forecast. A unique aspect of the LRUC is the satellite assimilation and the continuous recycling of the adjusted moisture availability field from one forecast cycle to the next. Preliminary results for a seven-day trial period indicate that hourly LST tendencies assimilated in a 1 hour LRUC showed improved simulated air and dewpoint

  18. DNA-Based Genetic Markers for Rapid Cycling Brassica Rapa (Fast Plants Type) Designed for the Teaching Laboratory

    PubMed Central

    Slankster, Eryn E.; Chase, Jillian M.; Jones, Lauren A.; Wendell, Douglas L.

    2012-01-01

    We have developed DNA-based genetic markers for rapid cycling Brassica rapa (RCBr), also known as Fast Plants. Although markers for B. rapa already exist, ours were intentionally designed for use in a teaching laboratory environment. The qualities we selected for were robust amplification in PCR, polymorphism in RCBr strains, and alleles that can be easily resolved in simple agarose slab gels. We have developed two single nucleotide polymorphism (SNP) based markers and 14 variable number tandem repeat (VNTR)-type markers spread over four chromosomes. The DNA sequences of these markers represent variation in a wide range of genomic features. Among the VNTR-type markers, there are examples of variation in a non-genic region, variation within an intron, and variation in the coding sequence of a gene. Among the SNP-based markers there are examples of polymorphism in intronic DNA and synonymous substitution in a coding sequence. Thus these markers can serve laboratory exercises in both transmission genetics and molecular biology. PMID:22675329

  19. DNA-Based Genetic Markers for Rapid Cycling Brassica Rapa (Fast Plants Type) Designed for the Teaching Laboratory.

    PubMed

    Slankster, Eryn E; Chase, Jillian M; Jones, Lauren A; Wendell, Douglas L

    2012-01-01

    We have developed DNA-based genetic markers for rapid cycling Brassica rapa (RCBr), also known as Fast Plants. Although markers for B. rapa already exist, ours were intentionally designed for use in a teaching laboratory environment. The qualities we selected for were robust amplification in PCR, polymorphism in RCBr strains, and alleles that can be easily resolved in simple agarose slab gels. We have developed two single nucleotide polymorphism (SNP) based markers and 14 variable number tandem repeat (VNTR)-type markers spread over four chromosomes. The DNA sequences of these markers represent variation in a wide range of genomic features. Among the VNTR-type markers, there are examples of variation in a non-genic region, variation within an intron, and variation in the coding sequence of a gene. Among the SNP-based markers there are examples of polymorphism in intronic DNA and synonymous substitution in a coding sequence. Thus these markers can serve laboratory exercises in both transmission genetics and molecular biology. PMID:22675329

  20. Genetic analysis of morphological traits in a new, versatile, rapid-cycling Brassica rapa recombinant inbred line population

    PubMed Central

    Bagheri, Hedayat; El-Soda, Mohamed; van Oorschot, Inge; Hanhart, Corrie; Bonnema, Guusje; Jansen-van den Bosch, Tanja; Mank, Rolf; Keurentjes, Joost J. B.; Meng, Lin; Wu, Jian; Koornneef, Maarten; Aarts, Mark G. M.

    2012-01-01

    A recombinant inbred line (RIL) population was produced based on a wide cross between the rapid-cycling and self-compatible genotypes L58, a Caixin vegetable type, and R-o-18, a yellow sarson oil type. A linkage map based on 160 F7 lines was constructed using 100 Single nucleotide polymorphisms (SNPs), 130 AFLP®, 27 InDel, and 13 publicly available SSR markers. The map covers a total length of 1150 centiMorgan (cM) with an average resolution of 4.3 cM/marker. To demonstrate the versatility of this new population, 17 traits, related to plant architecture and seed characteristics, were subjected to quantitative trait loci (QTL) analysis. A total of 47 QTLs were detected, each explaining between 6 and 54% of the total phenotypic variance for the concerned trait. The genetic analysis shows that this population is a useful new tool for analyzing genetic variation for interesting traits in B. rapa, and for further exploitation of the recent availability of the B. rapa whole genome sequence for gene cloning and gene function analysis. PMID:22912644

  1. Personal and Societal Construction of Illness Among Individuals With Rapid-Cycling Bipolar Disorder: A Life-Trajectory Perspective

    PubMed Central

    Sajatovic, Martha; Jenkins, Janis H.; Safavi, Roknedin; West, Jane A.; Cassidy, Kristin A.; Meyer, William J.; Calabrese, Joseph R.

    2011-01-01

    Objective Bipolar disorder is a chronic mental illness associated with substantial impairment in quality of life and function. Although there has been tremendous growth in understanding bipolar disorder with respect to treatments, very little study has focused on the viewpoint of affected individuals. The purpose of this study was to examine the subjective experience of illness among 19 men and women with rapid cycling bipolar disorder receiving treatment at an academic psychiatry clinic. Methods Personal constructs of illness with respect to life-trajectory and societal reaction to the individual, specifically the issue of stigma, were evaluated using a semistructured, open-ended anthropological interview. Results Participants perceived bipolar disorder as a disease with biologic underpinnings. Stigma was a major issue for all individuals. In common with individuals without serious mental illness, individuals with bipolar disorder work at mastering developmental tasks appropriate for their life stage. At times, younger individuals appeared to have difficulty separating their own identity from the effects of illness. For older individuals with bipolar disorder, life was perceived to be disrupted by bipolar disorder, with early plans and dreams often “derailed.” Conclusion Although bipolar disorder may severely alter an individual’s planned life trajectory, accomplishment of life goals can at least partially offset the sense of loss that is often seen in bipolar illness. PMID:18070834

  2. Assessment of the 60 km rapid update cycle (RUC) with near real-time aircraft reports. Project report

    SciTech Connect

    Cole, R.E.; Richard, C.; Kim, S.; Bailey, D.

    1998-07-15

    The National Aeronautics and Space Administration (NASA) is developing the Center-TRA-CON Advisory System (CTAS), a set of Air Traffic Management (ATM) Decision Support Tools (DST) for en route (Center) and terminal (TRACON) airspace designed to enable controllers to increase capacity and flight efficiency. A crucial component of the CTAS, or any ATM DST, is the computation of the time-of-flight of aircraft along flight path segments. Earlier NASA studies show that accurate knowledge of the wind through which the aircraft are flying is required to estimate time-of-flight accurately. There are current envisioned to be two sources of wind data for CTAS: The Rapid Update Cycle (RUC) for the Center airspace, a numerical model developed by the National Oceanic and Atmospheric Administration (NOAA) Forecast System Laboratory (FSL) and run operationally by the National Weather Service (NWS) National Center for Environmental Prediction (NCEP); and The Integrated Terminal Weather System (ITWS) Terminal Winds (TW) for the TRACON airspace, developed at MIT Lincoln Laboratory under funding from the Federal Aviation Administration (FAA). This study has three goals: (1) determine the errors in the baseline 60 km resolution RUC forecast wind fields relative to the needs of en route DSTs such as CTAS, (2) determine the benefit of using the TW algorithm to refine the RUC forecast wind fields with near real-time Meteorological Data Collection and Reporting System (MDCRS) reports, and (3) identify factors that influence wind errors in order to improve accuracy and estimate errors in real time.

  3. Effect of cross-link density and hydrophilicity of PU on blood compatibility of hydrophobic PS/hydrophilic PU IPNs.

    PubMed

    Roh, H W; Song, M J; Han, D K; Lee, D S; Ahn, J H; Kim, S C

    1999-01-01

    To investigate the effect of the hydrophilic and hydrophobic microdomain structure on blood compatibility, a series of interpenetrating polymer networks (IPNs) composed of hydrophilic polyurethane (PU) and hydrophobic polystyrene (PS) was prepared. One series was prepared with varying cross-link densities of each network, the other with varying hydrophilicity of the PU component. All PU/PS IPNs exhibited microphase-separated structures that had dispersed PS domains in the continuous PU matrix. The domain size decreased with decreasing the hydrophilicity of the PU component and increasing the cross-link density of each network. As the cross-link density and hydrophobicity of the PU component was increased, an inward shift of Tgs was observed, which was due to the decrease in phase separation between the hydrophobic PS component and hydrophilic PU component. In the in vitro platelet adhesion test, as the microdomain size of PU/PS IPN surface decreased, the number of adhered platelets on the PU/PS IPN surface was reduced and deformation of the adhered platelets decreased. It could be concluded that blood compatibility of PU/PS IPN was mainly affected by the degree of mixing between PU and PS component, which was reflected by the domain size of PS rich phase. PMID:10091927

  4. Teaching Human Genetics with Mustard: Rapid Cycling "Brassica rapa" (Fast Plants Type) as a Model for Human Genetics in the Classroom Laboratory

    ERIC Educational Resources Information Center

    Wendell, Douglas L.; Pickard, Dawn

    2007-01-01

    We have developed experiments and materials to model human genetics using rapid cycling "Brassica rapa", also known as Fast Plants. Because of their self-incompatibility for pollination and the genetic diversity within strains, "B. rapa" can serve as a relevant model for human genetics in teaching laboratory experiments. The experiment presented…

  5. Estrous cycle variations in GABAA receptor phosphorylation enable rapid modulation by anabolic androgenic steroids in the medial preoptic area

    PubMed Central

    Oberlander, JG; Porter, DM; Onakomaiya, MM; Penatti, CAA; Vithlani, M; Moss, SJ; Clark, AS; Henderson, LP

    2012-01-01

    Anabolic androgenic steroids (AAS), synthetic testosterone derivatives that are used for ergogenic purposes, alter neurotransmission and behaviors mediated by GABAA receptors. Some of these effects may reflect direct and rapid action of these synthetic steroids at the receptor. The ability of other natural allosteric steroid modulators to alter GABAA receptor-mediated currents is dependent upon the phosphorylation state of the receptor complex. Here we show that phosphorylation of the GABAA receptor complex immunoprecipitated by β2/β3 subunit-specific antibodies from the medial preoptic area (mPOA) of the mouse varies across the estrous cycle; with levels being significantly lower in estrus. Acute exposure to the AAS, 17α-testosterone (17α-MeT), had no effect on the amplitude or kinetics of inhibitory postsynaptic currents in the mPOA of estrous mice when phosphorylation was low, but increased the amplitude of these currents from mice in diestrus, when it was high. Inclusion of the protein kinase C (PKC) inhibitor, calphostin, in the recording pipette eliminated the ability of 17α-MeT to enhance currents from diestrous animals, suggesting that PKC-receptor phosphorylation is critical for the allosteric modulation elicited by AAS during this phase. In addition, a single injection of 17α-MeT was found to impair an mPOA-mediated behavior (nest-building) in diestrus, but not in estrus. PKC is known to target specific serine residues in the β3 subunit of the GABAA receptor. Although phosphorylation of these β3 serine residues showed a similar profile across the cycle, as did phosphoserine in mPOA lysates immunoprecipitated with β2/β3 antibody (lower in estrus than in diestrus or proestrus), the differences were not significant. These data suggest that the phosphorylation state of the receptor complex regulates both the ability of AAS to modulate receptor function in the mPOA and the expression of a simple mPOA-dependent behavior through PKC-dependent mechanism

  6. Cumulative frequency-dependent selective episodes allow for rapid morph cycles and rock-paper-scissors dynamics in species with overlapping generations

    PubMed Central

    San-Jose, Luis M.; Peñalver-Alcázar, Miguel; Milá, Borja; Gonzalez-Jimena, Virginia; Fitze, Patrick S.

    2014-01-01

    Rock-paper-scissors (RPS) dynamics, which maintain genetic polymorphisms over time through negative frequency-dependent (FD) selection, can evolve in short-lived species with no generational overlap, where they produce rapid morph frequency cycles. However, most species have overlapping generations and thus, rapid RPS dynamics are thought to require stronger FD selection, the existence of which yet needs to be proved. Here, we experimentally demonstrate that two cumulative selective episodes, FD sexual selection reinforced by FD selection on offspring survival, generate sufficiently strong selection to generate rapid morph frequency cycles in the European common lizard Zootoca vivipara, a multi-annual species with major generational overlap. These findings show that the conditions required for the evolution of RPS games are fulfilled by almost all species exhibiting genetic polymorphisms and suggest that RPS games may be responsible for the maintenance of genetic diversity in a wide range of species. PMID:24943372

  7. Single-crystal neutron diffraction studies of hydrogen-bonded systems: Two recent examples from IPNS

    NASA Astrophysics Data System (ADS)

    Koetzle, Thomas F.; Piccoli, Paula M. B.; Schultz, Arthur J.

    2009-02-01

    Beginning with work in the 1950s at the first generation of research reactors, studies of hydrogen-bonded systems have been a prime application for single-crystal neutron diffraction. The range of systems studied was extended in the 1960s and 1970s, with the advent of high flux reactor sources, and beginning around 1980 studies at pulsed neutron sources have made increasingly important contributions. Recently at the Argonne Intense Pulsed Neutron Source (IPNS), working with collaborators, we completed two studies of hydrogen-bonded systems that will serve to illustrate topics of current interest. In the first study, on andrographolide, an active diterpenoid natural product, our neutron diffraction results definitively characterize the hydrogen-bonding interactions. The second IPNS study is on tetraacetylethane (TAE), a β-diketone enol system with a very short, strong intramolecular O-H⋯O hydrogen bond. At IPNS, we have determined the neutron crystal structure of TAE at five temperatures between 20 and 298 K to investigate changes in the structure with temperature and to probe for disorder. Despite the successes illustrated by the two examples presented here and by many other studies, at present applications of single-crystal neutron diffraction continue to be extremely flux limited and constrained by the requirement for mm-size crystals for many problems. These limitations are being addressed through the realization of powerful instruments at a new generation of pulsed neutron sources, including in the USA the TOPAZ and MaNDi single-crystal diffractometers that are under development at the Spallation Neutron Source (SNS).

  8. Development of a Rapid Cycling CO(sub 2) and H(sub 2)O Removal Sorbent

    NASA Technical Reports Server (NTRS)

    Paul, Heather; Alptekin, Goekhan; Cates, Matthew; Bernal, Casey; Dubovik, Margarita; Gershanovich, Yevgenia

    2007-01-01

    The National Aeronautics and Space Administration (NASA) planned future missions set stringent demands on the design of the Portable Life Support System (PLSS), requiring dramatic reductions in weight, decreased reliance on supplies and greater flexibility on the types of missions. Use of regenerable systems that reduce weight and volume of the Extravehicular Mobility Unit (EMU) is of critical importance to NASA, both for low orbit operations and for long duration manned missions. The carbon dioxide and humidity control unit in the existing PLSS design is relatively large, since it has to remove and store 8 hours worth of CO2. If the sorbent regeneration can be carried out during the extravehicular activity (EVA) with a relatively high regeneration frequency, the size of the sorbent canister and weight can be significantly reduced. The progress of regenerable CO2 and humidity control is leading us towards the use of a rapid cycling amine system. TDA Research, Inc. is developing compact, regenerable sorbent materials to control CO2 and humidity in the space suit ventilation loop. The sorbent can be regenerated using space vacuum during the EVA, eliminating all carbon dioxide and humidity duration-limiting elements in the life support system. The material also has applications in other areas of space exploration such as the Orion spacecraft and other longer duration exploration missions requiring regenerable technologies. This paper summarizes the results of the sorbent development, testing, and evaluation efforts to date. The results of a preliminary system analysis are also included, showing the size and volume reductions for PLSS provided by the new system.

  9. Institute for Science Education. Institut fur die Padagogik der Naturwissenschaften an der Universitat Kiel. IPN Report-in-Brief 11. 3rd Edition.

    ERIC Educational Resources Information Center

    Blansdorf, Klaus, Ed.

    The Institut fur die Padagogik der Naturwissenschaften (IPN) is the research institute for science education, with a national function in the Federal Republic of Germany. The IPN consists of biology education, chemistry education, physics education, educational science, research methodology/statistics, and administration/general services…

  10. Characterizing the Performance of a Proton-Transfer-Reaction Mass Spectrometer with a Rapid Cycling Tenax Preconcentrator

    SciTech Connect

    Garland, S.P.; Alexander, M.L.

    2006-01-01

    Volatile organic compounds (VOCs) are species of interest for atmospheric modeling, worker chemical exposure and medical studies. Sometimes the required detection limits for these compounds is below the capability of existing real-time instrumentation. Preconcentrators have been implemented as an inexpensive way to amplify chemical signals and improve detection limits. Proton-transfer-reaction mass spectrometry (PTR-MS) has been used as a tool for studying low concentrations of VOCs, but it lacks the capability to differentiate chemical signal contributions from isobaric compounds. In this work, behavior of a newly designed Tenax TA preconcentrator when coupled with a PTRMS is characterized. This novel preconcentrator design allows rapid temperature cycling, maintaining near real-time response. The preconcentrator was exposed to a sample gas of toluene in varying concentrations and loading times between and then thermally desorbed for analysis by PTR-MS. The effects of preconcentrating multiple analytes simultaneously were also investigated as well as the chromatographic effects of the preconcentrator. A linear behavior was observed when the integrated ion count rates (ICPS) from thermal desorption peaks were regressed against both varying loading times at a constant toluene concentration and varying concentrations with constant loading times. From these trends, it is possible to determine the concentration of a VOC by knowing its ICPS from thermal desorption peaks from a known preconcentration time. Peak height ion count rates representing ultimate detectability were amplified by factors up to 257 times the original signal, extending the range of the PTR-MS from 50pptv to nearly 250 parts per quadrillion. This corresponds to an ultimate sensitivity of 200 parts per quadrillion with 20 minute time resolution. Quantitative preconcentrator behavior was demonstrated using ICPS from these ion peaks and were amplified as much as 148 times their original signal. Results

  11. Design and Development Comparison of Rapid Cycle Amine 1.0, 2.0, and 3.0

    NASA Technical Reports Server (NTRS)

    Chullen, Cinda; Campbell, Colin; Papale, William; Murray, Sean; Wichowski, Robert; Conger, Bruce; McMillin, Summer

    2016-01-01

    The development of the Rapid Cycle Amine (RCA) swing-bed technology for carbon dioxide (CO2) removal has been in progress since favorable results were published in 1996. Shortly thereafter, a prototype was designed, developed, and tested successfully and delivered to Johnson Space Center in 1999. An improved prototype was delivered to NASA in 2006 and was notated as RCA 1.0 and sized for the extravehicular activity (EVA). The new RCA swing-bed technology is a regenerative system which employs two alternating solid-amine sorbent beds to remove CO2 and water. The two- bed design employs a chemisorption process whereby the beds alternate between adsorbtion and desorbsion. This process provides for an efficient operation of the RCA so that while one bed is in adsorb (uptake) mode, the other is in the desorb (regeneration) mode. The RCA has now progressed through several iterations of technology readiness levels. Test articles have now been designed, developed, and tested for the advanced space suit portable life support system (PLSS) including RCA 1.0, RCA 2.0, and RCA 3.0. The RCA 3.0 was the most recent RCA fabrication and was delivered to NASA-JSC in June 2015. The RCA 1.0 test article was designed with a pneumatically actuated linear motion spool valve. The RCA 2.0 and 3.0 test articles were designed with a valve assembly which allows for switching between uptake and regeneration modes while minimizing gas volume losses to the vacuum source. RCA 2.0 and 3.0 also include an embedded controller design to control RCA operation and provide the capability of interfacing with various sensors and other ventilation loop components. The RCA technology is low power, small, and has fulfilled all test requirements levied upon the technology during development testing thus far. This paper will provide an overreview of the design and development of RCA 1.0, 2.0 and 3.0 including detail differences between the design specifications of each.

  12. Design and Development Comparison of Rapid Cycle Amine 1.0, 2.0, and 3.0

    NASA Technical Reports Server (NTRS)

    Chullen, Cinda; Campbell, Colin; Papale, William; Murray, Sean; Wichowski, Robert; Conger, Bruce; McMillin, Summer

    2016-01-01

    The development of the Rapid Cycle Amine (RCA) swing-bed technology for carbon dioxide (CO2) removal has been in progress since favorable results were published in 1996. Shortly thereafter, a prototype was designed, developed, and tested successfully and delivered to Johnson Space Center in 1999. An improved prototype (RCA 1.0) was delivered to NASA in 2006 and sized for the extravehicular activity (EVA). The RCA swing-bed technology is a regenerative system which employs two alternating solid-amine sorbent beds to remove CO2 and water. The two-bed design employs a chemisorption process whereby the beds alternate between adsorption and desorption. This process provides for an efficient RCA operation that enables one bed to be in adsorb (uptake) mode, while the other is in the desorb (regeneration) mode. The RCA has progressed through several iterations of technology readiness levels. Test articles have now been designed, developed, and tested for the advanced space suit portable life support system (PLSS) including RCA 1.0, RCA 2.0, and RCA 3.0. The RCA 3.0 was the most recent RCA fabrication and was delivered to NASA-JSC in June 2015. The RCA 1.0 test article was designed with a pneumatically actuated linear motion spool valve. The RCA 2.0 and 3.0 test articles were designed with a valve assembly which allows for switching between uptake and regeneration modes while minimizing gas volume losses to the vacuum source. RCA 2.0 and 3.0 also include an embedded controller design to control RCA operation and provide the capability of interfacing with various sensors and other ventilation loop components. The RCA technology is low power, small, and has fulfilled all test requirements levied upon the technology during development testing thus far. This paper will provide an overview of the design and development of RCA 1.0, 2.0 and 3.0 including detail differences between the design specifications of each. Nomenclature.

  13. Major CO2 source and sink perturbations of the global carbon cycle due to rapid emplacement of Continental Flood Basalts

    NASA Astrophysics Data System (ADS)

    Schaller, M. F.; Wright, J. D.; Kent, D. V.

    2011-12-01

    Recent evidence from the ~201.5 Ma Central Atlantic Magmatic Province (CAMP) in the Newark Rift Basin demonstrates that this Large Igneous Province (LIP) produced a transient doubling of atmospheric pCO2, followed by a ~300 kyr falloff to near pre-eruptive concentrations after each major eruptive episode (Schaller, Wright and Kent; Science, 2011). Here we similarly use pedogenic carbonates to test the million-year effects of the CAMP volcanism on Early Jurassic pCO2 in the corollary Hartford Basin of Eastern North America (ENA). In both basins we find a pre-CAMP pCO2 background of ~2000 ± 700 ppm, increasing to ~4500 ± 1600 ppm immediately above the first flow unit, followed by 300 kyr post-extrusive decrease to near background concentrations. The long post-extrusive section of the Hartford Basin shows the same ~300 kyr pCO2 decrease to pre-eruptive background, which continues to levels below pre-CAMP background over the subsequent 1.5 Myr following the final episode of eruptions. We use a geochemical model to demonstrate that the rapidity of the pCO2 decreases, and the fall to concentrations below background may be accounted for by a 1.5-fold amplification of the continental silicate weathering response due to the presence of the more highly weatherable CAMP basalts themselves. This indicates that continental flood basalts capable of producing a short-term perturbation of the carbon system may actually have an overall net-cooling effect on global climates due to a long-term net-decrease in pCO2 to below pre-eruptive levels. Analysis of the effusive potential for various submarine and continental LIPs based on reconstructed volumes suggests that those comparable to, or even larger than the CAMP may have had a significant effect on short term pCO2 concentrations, but this effect is highly dependent on effusive timescale. However, we pose the testable hypothesis that only continental flood basalts participate directly on both the CO2 source and sink side of the

  14. Low Temperature, Rapid Thermal Cycle Annealing of HgCdTe Grown on CdTe/Si

    NASA Astrophysics Data System (ADS)

    Simingalam, Sina; Brill, Gregory; Wijewarnasuriya, Priyalal; Rao, Mulpuri V.

    2015-05-01

    The HgCdTe(MCT) grown on CdTe/Si substrate has a high dislocation density due to lattice mismatch. Thermal cycle annealing (TCA) is effective in reducing the dislocation density. The TCA at high temperatures results in inter-diffusion of the constituent elements across the MCT/CdTe interface. In this study, we observed a reduction in dislocation density with good surface morphology due to proper design of the TCA system, low annealing temperature, and large number of annealing cycles. The ampoule containing the samples is placed in direct contact with the graphite heating tube which helps in increasing the heating and cooling rates of the annealing cycle. To maintain Hg overpressure, Hg is placed in the sample holder, instead of in the ampoule to avoid Hg condensation. The best results were obtained by cycling the annealing temperature between 290°C and 350°C. Anneals were performed by using 32, 64, 128 and 256 cycles. We obtained an etch pit density (EPD) as low as 1 × 106 cm-2. Lower EPD was not achieved either by increasing annealing temperature or number of annealing cycles. Through secondary ion mass spectroscopy analysis, we observed very little inter-diffusion of Cd across the MCT/CdTe interface for the 128 cycle annealing. These results show promise in bridging the gap in the device performance between the MCT material grown on CdTe/Si and CdZnTe substrates.

  15. Analysis of S-locus and expression of S-alleles of self-compatible rapid-cycling Brassica oleracea 'TO1000DH3'.

    PubMed

    Hee-Jeong, Jung; Nasar Uddin, Ahmed; Jong-In, Park; Senthil Kumar, Thamilarasan; Hye-Ran, Kim; Yong-Gu, Cho; Ill-Sup, Nou

    2014-10-01

    Brassica oleracea is a strictly self-incompatible (SI) plant, but rapid-cycling B. oleracea 'TO1000DH3' is self-compatible (SC). Self-incompatibility in Brassicaceae is controlled by multiple alleles of the S-locus. Three S-locus genes, S-locus glycoprotein (SLG), S-locus receptor kinase (SRK) and S-locus protein 11 or S-locus cysteine-rich (SP11/SCR), have been reported to date, all of which are classified into class I and II. In this study, we investigated the molecular mechanism behind alterations of SI to SC in rapid-cycling B. olerace 'TO1000DH3'. Class I SRK were identified by genomic DNA PCR and PCR-RFLP analysis using SRK specific markers and found to be homozygous. Cloning and sequencing of class I SRK revealed a normal kinase domain without any S-domain/transmembrane domain. Moreover, S-locus sequencing analysis revealed only an SLG sequence, but no SP11/SCR. Expression analysis showed no SRK expression in the stigma, although other genes involved in the SI recognition reaction (SLG, MLPK, ARC1, THL) were found to have normal expression in the stigma. Taken together, the above results suggest that structural aberrations such as deletion of the SI recognition genes may be responsible for the breakdown of SI in rapid-cycling B. oleracea 'TO1000DH3'. PMID:24969488

  16. VizieR Online Data Catalog: IPN supplement to the BeppoSAX GRB catalog (Hurley+, 2010)

    NASA Astrophysics Data System (ADS)

    Hurley, K.; Guidorzi, C.; Frontera, F.; Montanari, E.; Rossi, F.; Feroci, M.; Mazets, E.; Golenetskii, S.; Frederiks, D. D.; Pal'Shin, V. D.; Aptekar, R. L.; Cline, T.; Trombka, J.; McClanahan, T.; Starr, R.; Atteia, J.-L.; Barraud, C.; Pelangeon, A.; Boer, M.; Vanderspek, R.; Ricker, G.; Mitrofanov, I. G.; Golovin, D. V.; Kozyrev, A. S.; Litvak, M. L.; Sanin, A. B.; Boynton, W.; Fellows, C.; Harshman, K.; Goldsten, J.; Gold, R.; Smith, D. M.; Wigger, C.; Hajdas, W.

    2010-11-01

    Between 1996 July and 2002 April, the Wide Field X-Ray Camera (WFC) and Gamma-Ray Burst Monitor (GRBM) aboard the X-ray astronomy satellite BeppoSAX detected 62 and 1092 cosmic gamma-ray bursts (GRBs), respectively. These detections were used to initiate searches through the data of the spacecraft comprising the interplanetary network (IPN). (3 data files).

  17. Synthesis of wheat straw cellulose-g-poly (potassium acrylate)/PVA semi-IPNs superabsorbent resin.

    PubMed

    Liu, Jia; Li, Qian; Su, Yuan; Yue, Qinyan; Gao, Baoyu; Wang, Rui

    2013-04-15

    To better use wheat straw and minimize its negative impact on environment, a novel semi-interpenetrating polymer networks (semi-IPNs) superabsorbent resin (SAR) composed of wheat straw cellulose-g-poly (potassium acrylate) (WSC-g-PKA) network and linear polyvinyl alcohol (PVA) was prepared by polymerization in the presence of a redox initiating system. The structure and morphology of semi-IPNs SAR were characterized by means of FTIR, SEM and TGA, which confirmed that WSC and PVA participated in the graft polymerization reaction with acrylic acid (AA). The factors that can influence the water absorption of the semi-IPNs SAR were investigated and optimized, including the weight ratios of AA to WSC and PVA to WSC, the content of initiator and crosslinker, neutralization degree (ND) of AA, reaction temperature and time. The semi-IPNs SAR prepared under optimized synthesis condition gave the best water absorption of 266.82 g/g in distilled water and 34.32 g/g in 0.9 wt% NaCl solution. PMID:23544572

  18. Rapid Search for a Near-Infrared Counterpart of GRB 960924

    NASA Technical Reports Server (NTRS)

    Klose, S.; Stecklum, B.; Eisloffel, J.; Nassir, M. A.; Hurley, K.; Kouveliotou, C.; Meegan, C. A.; Fishman, G. J.; Barthelmy, S. D.; Cline, T. L.

    1998-01-01

    We report the results of a rapid search for a near-infrared counterpart of the very strong gamma-ray burst 960924. The survey was performed in JHK-prime only 3.5 days after the burst. It was centered at the most probable burster position and covers about 1/3 of the BACODINE/IPN/Huntsville error box represented by the intersection of the 1-sigma, BATSE error circle and the 3-sigma, IPN annulus. Second epoch observations were carried out in the near-infrared about 100 days and 500 days after the burst. No Near Infrared (NIR) transient source was detected within the surveyed IPN annulus to magnitude limits J is approximately 17.5 and K is approximately 15-5.

  19. Nitrogen cycling in canopy soils of tropical montane forests responds rapidly to indirect N and P fertilization.

    PubMed

    Matson, Amanda L; Corre, Marife D; Veldkamp, Edzo

    2014-12-01

    Although the canopy can play an important role in forest nutrient cycles, canopy-based processes are often overlooked in studies on nutrient deposition. In areas of nitrogen (N) and phosphorus (P) deposition, canopy soils may retain a significant proportion of atmospheric inputs, and also receive indirect enrichment through root uptake followed by throughfall or recycling of plant litter in the canopy. We measured net and gross rates of N cycling in canopy soils of tropical montane forests along an elevation gradient and assessed indirect effects of elevated nutrient inputs to the forest floor. Net N cycling rates were measured using the buried bag method. Gross N cycling rates were measured using (15) N pool dilution techniques. Measurements took place in the field, in the wet and dry season, using intact cores of canopy soil from three elevations (1000, 2000 and 3000 m). The forest floor had been fertilized biannually with moderate amounts of N and P for 4 years; treatments included control, N, P, and N + P. In control plots, gross rates of NH4 (+) transformations decreased with increasing elevation; gross rates of NO3 (-) transformations did not exhibit a clear elevation trend, but were significantly affected by season. Nutrient-addition effects were different at each elevation, but combined N + P generally increased N cycling rates at all elevations. Results showed that canopy soils could be a significant N source for epiphytes as well as contributing up to 23% of total (canopy + forest floor) mineral N production in our forests. In contrast to theories that canopy soils are decoupled from nutrient cycling in forest floor soil, N cycling in our canopy soils was sensitive to slight changes in forest floor nutrient availability. Long-term atmospheric N and P deposition may lead to increased N cycling, but also increased mineral N losses from the canopy soil system. PMID:24965673

  20. Observations of rising tune during the injection instability of IPNS RCS proton bunch.

    SciTech Connect

    Dooling, J. C.; Brumwell, F. R.; Donley, L. I.; Harkay, K. C.; Kustom, R. L.; Lien, M. K.; McMichael, G. E.; Middendorf, M. E.; Nassiri, A.; Wang, S.; Accelerator Systems Division

    2008-01-01

    In the rapid cycling synchrotron (RCS), a single proton bunch (h=1) is accelerated from 50 MeV to 450 MeV in approximately 14.2 ms. The bunch experiences an instability shortly after injection (<1 ms). During the first millisecond, the beam is bunched but little acceleration takes place; therefore this period is similar to a storage ring mode of operation. Natural vertical oscillations (assumed to be tune lines) show the vertical tune to be rising toward the bare tune value, suggesting neutralization of space charge and a reduction of its detuning effects. Neutralization time near injection ranges from 250 mus - 500 mus, depending on the background gas pressure. Oscillations move from the LSB to the USB before disappearing. Tune measurements made with a recently installed ferrite- magnet pinger system show the horizontal chromaticity to be positive early but approaching zero later in the cycle; on the other hand, the vertical chromaticity is negative throughout the cycle. During pinger studies near injection, two vertical lines are observed. Neutralization of the beam space charge implies the generation of plasma in the beam volume early in the cycle which may then dissipate as the time-varying electric fields of the beam become stronger.

  1. Verifying the IPN accuracy with the Bursting Pulsar and SGR1806-20

    SciTech Connect

    Hurley, K.; Kouveliotou, C.; Fishman, G.; Meegan, C.; Briggs, M.; Cline, T.; Kommers, J.; Boer, M.

    1998-05-16

    The well-known positions of the Bursting Pulsar (GROJ1744-28) and the soft gamma repeater SGR1806-20 represent 'space truth' data (the equivalent of 'ground truth' data in remote sensing) which can be used to verify the accuracy of the IPN location technique. About 500 bursts from GROJ1744-28, and several dozen bursts from SGR1806-20, have been observed jointly by BATSE and Ulysses. Using these data, we have been able to verify the timing accuracy of the Ulysses data in numerous spacecraft and experiment operating modes, the cross-correlation technique used to compare the light curves of gamma-ray bursts from different spacecraft, and the method used to derive burst positions by triangulation. We show that the uncertainties in the triangulation technique are dominated by count rate statistics, and that no systematic errors exist whose magnitude is comparable to the statistical errors.

  2. Utilization of the intense pulsed neutron source (IPNS) at Argonne National Laboratory for neutron activation analysis

    SciTech Connect

    Heinrich, R.R.; Greenwood, L.R.; Popek, R.J.; Schulke, A.W. Jr.

    1983-01-01

    The Intense Pulsed Neutron Source (IPNS) neutron scattering facility (NSF) has been investigated for its applicability to neutron activation analysis. A polyethylene insert has been added to the vertical hole VT3 which enhances the thermal neutron flux by a factor of two. The neutron spectral distribution at this position has been measured by the multiple-foil technique which utilized 28 activation reactions and the STAYSL computer code. The validity of this spectral measurement was tested by two irradiations of National Bureau of Standards SRM-1571 (orchard leaves), SRM-1575 (pine needles), and SRM-1645 (river sediment). The average thermal neutron flux for these irradiations normalized to 10 ..mu..amp proton beam is 4.0 x 10/sup 11/ n/cm/sup 2/-s. Concentrations of nine trace elements in each of these SRMs have been determined by gamma-ray spectrometry. Agreement of measured values to certified values is demonstrated to be within experiment error.

  3. A temperature control method for shortening thermal cycling time to achieve rapid polymerase chain reaction (PCR) in a disposable polymer microfluidic device

    NASA Astrophysics Data System (ADS)

    Bu, Minqiang; Perch-Nielsen, Ivan R.; Sørensen, Karen S.; Skov, Julia; Sun, Yi; Duong Bang, Dang; Pedersen, Michael E.; Hansen, Mikkel F.; Wolff, Anders

    2013-07-01

    We present a temperature control method capable of effectively shortening the thermal cycling time of polymerase chain reaction (PCR) in a disposable polymer microfluidic device with an external heater and a temperature sensor. The method employs optimized temperature overshooting and undershooting steps to achieve a rapid ramping between the temperature steps for DNA denaturation, annealing and extension. The temperature dynamics within the microfluidic PCR chamber was characterized and the overshooting and undershooting parameters were optimized using the temperature-dependent fluorescence signal from Rhodamine B. The method was validated with the PCR amplification of mecA gene (162 bp) from methicillin-resistant Staphylococcus aureus bacterium (MRSA), where the time for 30 cycles was reduced from 50 min (without over- and undershooting) to 20 min.

  4. Effects of quercetin on the sleep-wake cycle in rats: involvement of gamma-aminobutyric acid receptor type A in regulation of rapid eye movement sleep.

    PubMed

    Kambe, Daiji; Kotani, Makiko; Yoshimoto, Makoto; Kaku, Shinsuke; Chaki, Shigeyuki; Honda, Kazuki

    2010-05-12

    The bioflavonoid quercetin is widely found in plants and exerts a large number of biological activities such as anti-hypertensive and anti-inflammatory properties. However, the effect of quercetin on the sleep-wake cycle has not been investigated. In the present study, we investigated the effect of quercetin on sleep-wake regulation. Intraperitoneal administration of quercetin (200mg/kg) significantly increased non-rapid eye movement (non-REM) sleep during dark period in rats, while it significantly decreased REM sleep. The decrease in REM sleep induced by quercetin was blocked by intracerebroventricular (i.c.v.) injection of bicuculline, a GABA(A) receptor antagonist. In contrast, the increase in non-REM sleep induced by quercetin was not affected by i.c.v. injection of bicuculline. Therefore, the present results suggest that quercetin alters the sleep-wake cycle partly through activation of GABA(A) receptors. PMID:20303338

  5. ERK1/2 MAP kinases promote cell cycle entry by rapid, kinase-independent disruption of retinoblastoma-lamin A complexes.

    PubMed

    Rodríguez, Javier; Calvo, Fernando; González, José M; Casar, Berta; Andrés, Vicente; Crespo, Piero

    2010-11-29

    As orchestrators of essential cellular processes like proliferation, ERK1/2 mitogen-activated protein kinase signals impact on cell cycle regulation. A-type lamins are major constituents of the nuclear matrix that also control the cell cycle machinery by largely unknown mechanisms. In this paper, we disclose a functional liaison between ERK1/2 and lamin A whereby cell cycle progression is regulated. We demonstrate that lamin A serves as a mutually exclusive dock for ERK1/2 and the retinoblastoma (Rb) protein. Our results reveal that, immediately after their postactivation entrance in the nucleus, ERK1/2 dislodge Rb from its interaction with lamin A, thereby facilitating its rapid phosphorylation and consequently promoting E2F activation and cell cycle entry. Interestingly, these effects are independent of ERK1/2 kinase activity. We also show that cellular transformation and tumor cell proliferation are dependent on the balance between lamin A and nuclear ERK1/2 levels, which determines Rb accessibility for phosphorylation/inactivation. PMID:21115804

  6. Reduced mRNA Expression of PTGDS in Peripheral Blood Mononuclear Cells of Rapid-Cycling Bipolar Disorder Patients Compared with Healthy Control Subjects

    PubMed Central

    Peijs, Lone; Kessing, Lars Vedel; Vinberg, Maj

    2015-01-01

    Background: Disturbances related to the arachidonic acid cascade and prostaglandin metabolism may be involved in the pathophysiology of bipolar disorder, as supported by a recent genome-wide association study meta-analysis; however, evidence from clinical studies on a transcriptional level is lacking. Two enzymes in the arachidonic acid cascade are the prostaglandin D synthase (PTGDS), which catalyzes the conversion of prostaglandin H2 to prostaglandin D2 (PGD2), and the aldo-keto reductase family 1 member C3 (AKR1C3), which catalyzes the reduction of PGD2. We aimed to test the hypothesis that mRNA expression of PTGDS and AKR1C3 is deregulated in rapid-cycling disorder patients in a euthymic or current affective state compared with healthy control subjects, and that expression alters with affective states. Methods: PTGDS and AKR1C3 mRNA expression in peripheral blood mononuclear cells was measured in 37 rapid-cycling bipolar disorder patients and 40 age- and gender-matched healthy control subjects using reverse transcription quantitative real-time polymerase chain reaction. Repeated measurements of PTGDS and AKR1C3 mRNA expression were obtained in various affective states during 6–12 months and compared with repeated measurements in healthy control subjects. Results: Adjusted for age and gender, PTGDS mRNA expression was down-regulated in rapid-cycling bipolar disorder patients in a euthymic, depressive, and manic/hypomanic state compared with healthy control subjects. No difference in PTGDS mRNA expression was observed between affective states. AKR1C3 mRNA expression did not differ between bipolar disorder patients in any affective state or in comparison with healthy control subjects. Conclusions: The results suggest a role for aberrantly-regulated PTGDS mRNA expression in rapid-cycling bipolar disorder. The sample size was limited; replication of the findings in larger, independent samples is warranted to further explore the role of the arachidonic acid cascade

  7. HIV-1 protein gp120 rapidly impairs memory in chicks by interrupting the glutamate-glutamine cycle.

    PubMed

    Fernandes, S P; Edwards, T M; Ng, K T; Robinson, S R

    2007-01-01

    Learning and memory impairments are frequently observed in patients suffering from AIDS Dementia Complex (ADC). These effects have been linked to the presence of gp120, an HIV viral coat glycoprotein. The present study investigated the possibility that gp120 prevents the uptake of extracellular glutamate by astrocytes, leading to an interruption of the glutamate-glutamine cycle and a subsequent impairment of memory. Ten microliters of 10nM gp120 was bilaterally injected into the region of the intermediate medial mesopallium of day-old chicks at various times before, or after, training using a single-trial passive avoidance task. Gp120 was found to significantly impair memory retention when injected 10-40 min after training. Memory impairments were evident within 5 min of gp120 administration and remained evident 24h later. Further, the amnestic effect of gp120 could be overcome with glutamine or with precursors of glutamate synthesis, but only weakly by glutamate. These results support the conclusion that the amnestic effect of gp120 is due to an impaired uptake of glutamate by astrocytes and a subsequent interruption of glutamine supply to neurones. The data indicate that the glutamate-glutamine cycle may be a useful therapeutic target in the treatment of ADC. PMID:16714124

  8. Synthesis and characterization of polymers and interpenetrating polymer networks (IPNs) with nonlinear optical (NLO) properties and related numerical studies

    NASA Astrophysics Data System (ADS)

    Sharma, P. R. Srikanth

    Copolymers of methyl methacrylate (MMA) and 2-propenoic acid, 2-methyl-, 2-[[[[4-methyl-3-[[[2-methyl-4-nitrophenyl)amino]carbonyl]aminophenyl]carbonyl]oxy]ethyl ester (PAMEE) exhibiting nonlinear optical (NLO) properties have been synthesized. Two kinds of urethane containing interpenetrating polymer networks (IPNs), consisting of nonlinear optical (NLO) chromophore, 2-methyl-4-nitroaniline (MNA) or Disperse Red1 (DR1) have been synthesized. The IPN systems consist of either aliphatic polycarbonate urethane (PCU) or 2,6-dimethyl-1,4-phenylene oxide (PPO) as one network and crosslinked poly (MMA-co-PAMEE) or poly (MMA-co-PMNEE) as the second network. Copolymers and interpenetrating polymer networks (IPNs) were characterized by IR spectroscopy, UV-VIS spectroscopy, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and second harmonic generation (SHG) measurements. The thin films of copolymers and IPNs were optically transparent and the corona poled polymers produced relatively large and stable SHG signals at room temperature. To understand the polarization decay of our NLO polymer we studied a simple theoretical model which can account for the main features which we observe. The addition of an apparent "chemical" reaction with a reaction activation energy EAB to the neighbor-facilitated Fredrickson-Anderson model shows the existence of a beta relaxation occurring simultaneously with the main alpha process. The combination of an Ising-model with antiferromagnetic interaction and the neighbor-facilitated Fredrickson-Anderson model allows a description of the polarization decay of polarized materials, such as our polymers, below the glass transition temperature Tg. The relaxation time for the polarization scales with the relaxation time of the alpha-process of the glass transition, and shows a typical curvature in the ln tau versus T-1 plot. Real polymers, such as poly(MMA-co-PAMEE) which we study possess both of these features and its

  9. Elevated transcription of the p53 gene in early S-phase leads to a rapid DNA-damage response during S-phase of the cell cycle.

    PubMed

    Takahashi, Paula; Polson, Amanda; Reisman, David

    2011-09-01

    p53 induces the transcription of genes that negatively regulate progression of the cell cycle in response to DNA damage or other cellular stressors, and thus participates in maintaining genome stability. Under stress conditions, p53 must be activated to prohibit the replication of cells containing damaged DNA. However, in normal, non-stressed cells, p53 activity must be inhibited. Previous studies have demonstrated that p53 transcription is activated before or during early S-phase in cells progressing from G(0)/G(1) into S-phase. Since this is not what would be predicted from a gene involved in growth arrest and apoptosis, in this study, we provide evidence that this induction occurs to provide sufficient p53 mRNA to ensure a rapid response to DNA damage before exiting S-phase. When comparing exponentially growing Swiss3T3 cells to those synchronized to enter S-phase simultaneously and treated with the DNA damaging agent camptothecin, we found that with cells in S-phase, p53 protein levels increased earlier, Bax and p21 transcription was activated earlier and to a greater extent and apoptosis occurred earlier and to a greater extent. These findings are consistent with p53 transcription being induced in S-phase to provide for a rapid DNA-damage response during S-phase of the cell cycle. PMID:21710255

  10. Rapid phase adjustment of melatonin and core body temperature rhythms following a 6-h advance of the light/dark cycle in the horse

    PubMed Central

    Murphy, Barbara A; Elliott, Jeffrey A; Sessions, Dawn R; Vick, Mandi M; Kennedy, Erin L; Fitzgerald, Barry P

    2007-01-01

    Background Rapid displacement across multiple time zones results in a conflict between the new cycle of light and dark and the previously entrained program of the internal circadian clock, a phenomenon known as jet lag. In humans, jet lag is often characterized by malaise, appetite loss, fatigue, disturbed sleep and performance deficit, the consequences of which are of particular concern to athletes hoping to perform optimally at an international destination. As a species renowned for its capacity for athletic performance, the consequences of jet lag are also relevant for the horse. However, the duration and severity of jet lag related circadian disruption is presently unknown in this species. We investigated the rates of re-entrainment of serum melatonin and core body temperature (BT) rhythms following an abrupt 6-h phase advance of the LD cycle in the horse. Methods Six healthy, 2 yr old mares entrained to a 12 h light/12 h dark (LD 12:12) natural photoperiod were housed in a light-proofed barn under a lighting schedule that mimicked the external LD cycle. Following baseline sampling on Day 0, an advance shift of the LD cycle was accomplished by ending the subsequent dark period 6 h early. Blood sampling for serum melatonin analysis and BT readings were taken at 3-h intervals for 24 h on alternate days for 11 days. Disturbances to the subsequent melatonin and BT 24-h rhythms were assessed using repeated measures ANOVA and analysis of Cosine curve fitting parameters. Results We demonstrate that the equine melatonin rhythm re-entrains rapidly to a 6-h phase advance of an LD12:12 photocycle. The phase shift in melatonin was fully complete on the first day of the new schedule and rhythm phase and waveform were stable thereafter. In comparison, the advance in the BT rhythm was achieved by the third day, however BT rhythm waveform, especially its mesor, was altered for many days following the LD shift. Conclusion Aside from the temperature rhythm disruption, rapid

  11. Novel semi-IPN based on crosslinked carboxymethyl starch and clay for the in vitro release of theophylline.

    PubMed

    Anirudhan, T S; Parvathy, J

    2014-06-01

    A novel semi-interpenetrating polymer network (IPN) based on crosslinked carboxymethyl starch (CL-CMS) and montmorillonite (MMT) was prepared, where carboxymethylation occurs as a result of the reaction between native starch and monochloroacetic acid in isopropanol/water medium at 60°C. The carboxymethyl starch is further crosslinked and made into a semi-IPN with MMT for the release of theophylline. The drug carrier was characterized using FTIR, XRD and surface analysis using SEM. Studies including physio-chemical analysis, swelling behavior, encapsulation efficiency, effect of MMT content, effect of ionic strength and in vitro drug release were carried out. Theophylline encapsulation of up to 74% was achieved and drug release was monitored in SGF (pH 1.2) and SIF (pH 7.4). Results show that the matrix releases drug at a much faster rate in the basic medium than in the acidic medium, thereby holding the promise of developing the semi-IPN system as a potential candidate for the release of theophylline. PMID:24685463

  12. Rapid Ammonia Gas Transport Accounts for Futile Transmembrane Cycling under NH3/NH4+ Toxicity in Plant Roots1[C][W

    PubMed Central

    Coskun, Devrim; Britto, Dev T.; Li, Mingyuan; Becker, Alexander; Kronzucker, Herbert J.

    2013-01-01

    Futile transmembrane NH3/NH4+ cycling in plant root cells, characterized by extremely rapid fluxes and high efflux to influx ratios, has been successfully linked to NH3/NH4+ toxicity. Surprisingly, the fundamental question of which species of the conjugate pair (NH3 or NH4+) participates in such fluxes is unresolved. Using flux analyses with the short-lived radioisotope 13N and electrophysiological, respiratory, and histochemical measurements, we show that futile cycling in roots of barley (Hordeum vulgare) seedlings is predominately of the gaseous NH3 species, rather than the NH4+ ion. Influx of 13NH3/13NH4+, which exceeded 200 µmol g–1 h–1, was not commensurate with membrane depolarization or increases in root respiration, suggesting electroneutral NH3 transport. Influx followed Michaelis-Menten kinetics for NH3 (but not NH4+), as a function of external concentration (Km = 152 µm, Vmax = 205 µmol g–1 h–1). Efflux of 13NH3/13NH4+ responded with a nearly identical Km. Pharmacological characterization of influx and efflux suggests mediation by aquaporins. Our study fundamentally revises the futile-cycling model by demonstrating that NH3 is the major permeating species across both plasmalemma and tonoplast of root cells under toxicity conditions. PMID:24134887

  13. Dansgaard-Oeschger Cycles and the California Current System: Planktonic foraminiferal response to rapid climate change in Santa Barbara Basin, Ocean Drilling Program Hole 893A

    NASA Astrophysics Data System (ADS)

    Hendy, Ingrid L.; Kennett, James P.

    2000-02-01

    High-resolution planktonic foraminiferal census data from Santa Barbara Basin (Ocean Drilling Program hole 893A) demonstrate major assemblage switches between 25 and 60 ka that were associated with Dansgaard-Oeschger cycles. Stadials dominated by Neogloboquadrina pachyderma (sinistral), and Globigerinoides glutinata suggest a strong subpolar California Current influence, while interstadials marked by abundant N. pachyderma (dextral) and G. bulloides indicate a relative increase in subtropical countercurrent influence. Modern analog technique and transfer function (F-20RSC) temperature reconstructions support δ18O evidence of large rapid (70 years or less) sea surface temperature shifts (3° to 5°C) between stadials and interstadials. Changes in the vertical temperature gradient and water column structure (thermocline depth) are recorded by planktonic faunal oscillations suggest bimodal stability in the organization of North Pacific surface ocean circulation. Santa Barbara Basin surface water demonstrates the rapid response of the California Current System to reorganization of North Pacific atmospheric circulation during rapid climate change. Supporting assemblage data are, available on diskette or via Anonymous FTP from Kosmos.agu.org, Directory APEND (username = anonymous, Password = guest). Diskette may be ordered from American Geophysical Union, 2000 Florida Avenue, N.W., Washington, DC 20009 or by phone at 800-966-2481; $5.00. Payment must accompany order.

  14. Longitudinal painting with large amplitude second harmonic rf voltages in the rapid cycling synchrotron of the Japan Proton Accelerator Research Complex

    NASA Astrophysics Data System (ADS)

    Tamura, Fumihiko; Yamamoto, Masanobu; Yoshii, Masahito; Ohmori, Chihiro; Nomura, Masahiro; Schnase, Alexander; Toda, Makoto; Suzuki, Hiromitsu; Shimada, Taihei; Hara, Keigo; Hasegawa, Katsushi

    2009-04-01

    In the rapid cycling synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC), the longitudinal painting is important to alleviate the space-charge effects. It is known that the momentum offset injection and applying the second harmonic rf voltage improves the bunching factor, which is defined as the ratio of average and peak current. Our simulation studies show that the large-amplitude second harmonic, 80% to the fundamental, is optimum, and the second harmonic phase sweep improves the bunching factor at the beginning of the injection period. We performed the beam tests of longitudinal painting in the J-PARC RCS. We proved that the longitudinal painting with the 80% second harmonic, the momentum offset of -0.2%, and the second harmonic phase sweep improved bunching factors significantly.

  15. Integration of BpMADS4 on various linkage groups improves the utilization of the rapid cycle breeding system in apple.

    PubMed

    Weigl, Kathleen; Wenzel, Stephanie; Flachowsky, Henryk; Peil, Andreas; Hanke, Magda-Viola

    2015-02-01

    Rapid cycle breeding in apple is a new approach for the rapid introgression of agronomically relevant traits (e.g. disease resistances) from wild apple species into domestic apple cultivars (Malus × domestica Borkh.). This technique drastically shortens the long-lasting juvenile phase of apple. The utilization of early-flowering apple lines overexpressing the BpMADS4 gene of the European silver birch (Betula pendula Roth.) in hybridization resulted in one breeding cycle per year. Aiming for the selection of non-transgenic null segregants at the end of the breeding process, the flower-inducing transgene and the gene of interest (e.g. resistance gene) that will be introgressed by hybridization need to be located on different chromosomes. To improve the flexibility of the existing approach in apple, this study was focused on the development and characterization of eleven additional BpMADS4 overexpressing lines of four different apple cultivars. In nine lines, the flowering gene was mapped to different linkage groups. The differences in introgressed T-DNA sequences and plant genome deletions post-transformation highlighted the unique molecular character of each line. However, transgenic lines demonstrated no significant differences in flower organ development and pollen functionality compared with non-transgenic plants. Hybridization studies using pollen from the fire blight-resistant wild species accession Malus fusca MAL0045 and the apple scab-resistant cultivar 'Regia' indicated that BpMADS4 introgression had no significant effect on the breeding value of each transgenic line. PMID:25370729

  16. Smart Macroporous IPN Hydrogels Responsive to pH, Temperature, and Ionic Strength: Synthesis, Characterization, and Evaluation of Controlled Release of Drugs.

    PubMed

    Dragan, Ecaterina Stela; Cocarta, Ana Irina

    2016-05-18

    Fast responsive macroporous interpenetrating polymer network (IPN) hydrogels were fabricated in this work by a sequential strategy, as follows: the first network, consisting of poly(N,N-dimethylaminoethyl methacrylate) (PDMAEM) cross-linked with N,N'-methylenebisacrylamide (BAAm), was prepared at -18 °C, the second network consisting of poly(acrylamide) (PAAm) cross-linked with BAAm, being also generated by cryogelation technique. Both single network cryogels (SNC) and IPN cryogels were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and water uptake. The presence of weak polycation PDMAEM endows the SNCs and the IPNs cryogels with sensitivity at numerous external stimuli such as pH, temperature, ionic strength, electric field, among which the first three were investigated in this work. It was found that the initial concentration of monomers in both networks was the key factor in tailoring the properties of IPN cryogels such as swelling kinetics, equilibrium water content (EWC), phase transition temperature and the response at ionic strength. The pore size increased after the formation of the second network, the swelling kinetics in pure water being comparable with that of the SNC, phase transition temperature being situated in the range 35-36 °C for IPN cryogels. The water uptake at equilibrium (WUeq) abruptly increased at pH < 3.0 in the case of SNCs, whereas the response of IPN cryogels at the decrease of pH from 6.0 to 1.0 was strongly dependent on the gel structure, the values of WUeq being lower at a higher concentration of DMAEM in the first network, the monomer concentration in the second network being about 10 wt %. The pH response was very much diminished when the monomer concentration was high in both networks (15 wt % in the first network, and 21 wt % in the second network). The increase of the ionic strength from 0 up to 0.3 M NaCl led to the decrease of the WUeq, for all cryogels, the level of dehydration

  17. Saccadic Performance and Cortical Excitability as Trait-Markers and State-Markers in Rapid Cycling Bipolar Disorder: A Two-Case Follow-Up Study

    PubMed Central

    Malsert, Jennifer; Guyader, Nathalie; Chauvin, Alan; Polosan, Mircea; Szekely, David; Bougerol, Thierry; Marendaz, Christian

    2013-01-01

    Background: The understanding of physiopathology and cognitive impairments in mood disorders requires finding objective markers. Mood disorders have often been linked to hypometabolism in the prefrontal dorsolateral cortex, and to GABAergic and glutamatergic neurotransmission dysfunction. The present study aimed to discover whether saccadic tasks (involving DPLFC activity), and cortical excitability (involving GABA/Glutamate neurotransmission) could provide neuropsychophysical markers for mood disorders, and/or of its phases, in patients with rapid cycling bipolar disorders (rcBD). Methods: Two rcBD patients were followed for a cycle, and were compared to nine healthy controls. A saccade task, mixing prosaccades, antisaccades, and nosaccades, and an evaluation of cortical excitability using transcranial magnetic stimulation were performed. Results: We observed a deficit in antisaccade in patients independently of thymic phase, and in nosaccade in the manic phase only. Cortical excitability data revealed global intracortical deficits in all phases, switching according to cerebral hemisphere and thymic phase. Conclusion: Specific patterns of performance in saccade tasks and cortical excitability could characterize mood disorders (trait-markers) and its phases (state-markers). Moreover, a functional relationship between oculometric performance and cortical excitability is discussed. PMID:23293609

  18. Rapid acceleration of ferrous iron/peroxymonosulfate oxidation of organic pollutants by promoting Fe(III)/Fe(II) cycle with hydroxylamine.

    PubMed

    Zou, Jing; Ma, Jun; Chen, Liwei; Li, Xuchun; Guan, Yinghong; Xie, Pengchao; Pan, Chao

    2013-10-15

    The reaction between ferrous iron (Fe(II)) with peroxymonosulfate (PMS) generates reactive oxidants capable of degrading refractory organic contaminants. However, the slow transformation from ferric iron (Fe(III)) back to Fe(II) limits its widespread application. Here, we added hydroxylamine (HA), a common reducing agent, into Fe(II)/PMS process to accelerate the transformation from Fe(III) to Fe(II). With benzoic acid (BA) as probe compound, the addition of HA into Fe(II)/PMS process accelerated the degradation of BA rapidly in the pH range of 2.0-6.0 by accelerating the key reactions, including the redox cycle of Fe(III)/Fe(II) and the generation of reactive oxidants. Both sulfate radicals and hydroxyl radicals were considered as the primary reactive oxidants for the degradation of BA in HA/Fe(II)/PMS process with the experiments of electron spin resonance and alcohols quenching. Moreover, HA was gradually degraded to N2, N2O, NO2 (−), and NO3 (−), while the environmentally friendly gas of N2 was considered as its major end product in the process. The present study might provide a promising idea based on Fe(II)/PMS process for the rapid degradation of refractory organic contaminants in water treatment. PMID:24033112

  19. Synthesis and Properties of pH-, Thermo-, and Salt-Sensitive Modified Poly(aspartic acid)/Poly(vinyl alcohol) IPN Hydrogel and Its Drug Controlled Release.

    PubMed

    Lu, Jingqiong; Li, Yinhui; Hu, Deng; Chen, Xiaoling; Liu, Yongmei; Wang, Liping; Zhao, Yansheng

    2015-01-01

    Modified poly(aspartic acid)/poly(vinyl alcohol) interpenetrating polymer network (KPAsp/PVA IPN) hydrogel for drug controlled release was synthesized by a simple one-step method in aqueous system using poly(aspartic acid) grafting 3-aminopropyltriethoxysilane (KH-550) and poly(vinyl alcohol) (PVA) as materials. The hydrogel surface morphology and composition were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The thermal stability was analyzed by thermogravimetric analysis (TGA). The swelling properties and pH, temperature, and salt sensitivities of KPAsp, KPAsp/PVA semi-interpenetrating polymer network (semi-IPN), and KPAsp/PVA IPN hydrogels were also investigated. All of the three hydrogels showed ampholytic pH-responsive properties, and swelling behavior was also extremely sensitive to the temperature, ionic strength, and cationic species. Finally, the drug controlled release properties of the three hydrogels were evaluated and results indicated that three hydrogels could control drug release by external surroundings stimuli. The drug controlled release properties of KPAsp/PVA IPN hydrogel are the most outstanding, and the correlative measured release profiles of salicylic acid at 37°C were 32.6 wt% at pH = 1.2 (simulated gastric fluid) and 62.5 wt% at pH = 7.4 (simulated intestinal fluid), respectively. These results indicated that KPAsp/PVA IPN hydrogels are a promising carrier system for controlled drug delivery. PMID:26351630

  20. Synthesis and characterization of a novel semi-IPN hydrogel based on Salecan and poly(N,N-dimethylacrylamide-co-2-hydroxyethyl methacrylate).

    PubMed

    Hu, Xinyu; Feng, Liandong; Wei, Wei; Xie, Aming; Wang, Shiming; Zhang, Jianfa; Dong, Wei

    2014-05-25

    Salecan is a novel water-soluble, high molecular mass extracellular β-glucan produced by Agrobacterium sp. ZX09. Salecan has excellent physicochemical and biological properties, making it very suitable for hydrogel preparation. In this study, a series of novel semi-interpenetrating polymer network (semi-IPN) hydrogels containing Salecan and poly(N,N-dimethylacrylamide-co-2-hydroxyethylmethacrylate) (poly(DMAA-co-HEMA)) were synthesized by radical polymerization and semi-IPN technology. Structure and morphology of the hydrogels were characterized by FTIR, XRD, TGA and SEM. The semi-IPNs had a well-interconnected porous structure with tunable pore size ranging from 6 to 41μm. Swelling capability of the hydrogels was improved by introducing the hydrophilic Salecan. Rheological results indicated that the incorporation of poly(DMAA-co-HEMA) into hydrogels enhanced the storage modulus. Compression tests revealed that these semi-IPNs were robust materials with compressive modulus between 13.3 and 90.5kPa, the addition of Salecan increased the fracture strain from 71.1% to 88.8%. Degradation and cytotoxicity tests demonstrated that semi-IPNs were degradable and non-toxic. PMID:24708962

  1. Synthesis and Properties of pH-, Thermo-, and Salt-Sensitive Modified Poly(aspartic acid)/Poly(vinyl alcohol) IPN Hydrogel and Its Drug Controlled Release

    PubMed Central

    Lu, Jingqiong; Li, Yinhui; Hu, Deng; Chen, Xiaoling; Liu, Yongmei; Wang, Liping; Zhao, Yansheng

    2015-01-01

    Modified poly(aspartic acid)/poly(vinyl alcohol) interpenetrating polymer network (KPAsp/PVA IPN) hydrogel for drug controlled release was synthesized by a simple one-step method in aqueous system using poly(aspartic acid) grafting 3-aminopropyltriethoxysilane (KH-550) and poly(vinyl alcohol) (PVA) as materials. The hydrogel surface morphology and composition were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The thermal stability was analyzed by thermogravimetric analysis (TGA). The swelling properties and pH, temperature, and salt sensitivities of KPAsp, KPAsp/PVA semi-interpenetrating polymer network (semi-IPN), and KPAsp/PVA IPN hydrogels were also investigated. All of the three hydrogels showed ampholytic pH-responsive properties, and swelling behavior was also extremely sensitive to the temperature, ionic strength, and cationic species. Finally, the drug controlled release properties of the three hydrogels were evaluated and results indicated that three hydrogels could control drug release by external surroundings stimuli. The drug controlled release properties of KPAsp/PVA IPN hydrogel are the most outstanding, and the correlative measured release profiles of salicylic acid at 37°C were 32.6 wt% at pH = 1.2 (simulated gastric fluid) and 62.5 wt% at pH = 7.4 (simulated intestinal fluid), respectively. These results indicated that KPAsp/PVA IPN hydrogels are a promising carrier system for controlled drug delivery. PMID:26351630

  2. [Compton GRO Cycle 7

    NASA Technical Reports Server (NTRS)

    Kippen, R. Marc

    2000-01-01

    The goals of this project were to use the improved location accuracy of combined BATSE/Ulysses-IPN gamma-ray burst (GRB) data to search for small-angle clustering within the burst population and to search for possible correlations between bursts and catalogs of known astrophysical objects. The research was completed in several phases due to the length of time needed to process the basic BATSE/Ulysses data and to develop the appropriate analysis algorithms. In the first phase, BATSE/Ulysses data were gathered from their respective sources and processed to yield, final BATSE burst catalog locations and final BATSE/Ulysses IPN timing annuli. The final data are published. In the next phase, traditional statistical analysis techniques were used to search a subset of the data for small-angle clustering and. correlations, and to produce upper limits. Next, the unique analysis techniques and software described in the proposal were developed and,applied to the final set of data (corresponding to the 4B catalog). The final search did not find any significant self-clustering or correlations with supernovae, AGN, or near by galaxy clusters. The investigation ruled-out earlier findings that indicated (with marginal significance) such results, and. provided stringent limits on the allowable fraction of bursts that are self-clustered and associated with selected known objects. An added benefit of this research came in 1998 when it was suggested that some gamma-ray bursts may be associated with supernova (SN) explosions. We responded rapidly and applied the tools of this investigation to study this possibility. Using combined BATSE/Ulysses data, we were able to completely rule out any association between bright bursts and known supernovae, thereby questioning the validity of any GRB/SN association. If a GRB/SN association exists, it must be only with a small fraction of weak bursts.

  3. Rapid changes in temperature and hydrology in the western Mediterranean during the last climatic cycle from the high resolution record ODP Site 976 (Alboran Sea)

    NASA Astrophysics Data System (ADS)

    Combourieu-Nebout, Nathalie; Peyron, Odile; Bout-Roumazeille, Viviane

    2013-04-01

    High-resolution pollen record, pollen-inferred climate reconstructions and clay mineralogy records were performed over the last climatic cycle from the ODP Site 976 located in the Alboran Sea Continental paleoenvironment proxies were provided on the same samples to depict the short and long term variability of Mediterranean vegetation and climate during the two last terminations and the last two interglacials. Pollen record highlights the vegetation changes associated to climate variability while clay mineralogy informs about the terrigenous inputs related to wind and/or river transport. During the last cycle, both vegetation and clay minerals data have recorded the response of continental ecosystems to all the climate events which characterized the last 135000 years. The Dansgaard/Oeschger oscillations and the rapid cold events evidenced in the North Atlantic (Bond et al., 1993; McManus et al., 1994) are well evidenced in the ODP sequence. Thus, warm interstadials show a strong colonisation of temperate Mediterranean forest while cold events are particularly well expressed by correlative increases in dry steppic to semi-desert formation with enhanced input from African desert dust (Bout-Roumazeilles et al, 2007 and in progress). A special attention has been paid on the two last glacial/interglacial transitions 1 and 2 that occurred before the interglacial inception in order to better understand what happened during these key-periods in continental areas and also better understand how reacts the Mediterranean climate regime through these two periods. The two high resolution records from the Terminaison 2/ Stage 5 and Terminaison 1/ Holocene are compared especially with regards to the wind regime modifications through atmospheric supply, and to hydrological and temperature changes reconstructed from pollen data. Therefore for these two key-periods, we aim to produce a robust climate reconstruction pollen-inferred precipitation and temperature from the 0DP 976 marine

  4. Preparation and characterization of a novel IPN hydrogel memberane of poly( N-isopropylacrylamide)/carboxymethyl chitosan (PNIPAAM/CMCS)

    NASA Astrophysics Data System (ADS)

    Chen, Jie; Sun, Jie; Yang, Liming; Zhang, Qunfei; Zhu, Huina; Wu, Huifeng; Hoffman, Allan S.; Kaetsu, Isao

    2007-08-01

    A novel type of interpenetrating polymer networks (IPN) hydrogel membrane of poly( N-isopropylacrylamide)/carboxymethyl chitosan (PNIPAAm)/(CMCS) was prepared, and the effects of the feed ratio of components, swelling medium and irradiation dose on the swelling and deswelling properties of the hydrogel was systematically studied. The results showed that the introduction of CMCS did not shift the LCST (at 32 °C), which is similar to the pure PNIPAAm. The lowest swelling ratio was at pH 2. There was little influence of irradiation dose on the thermo- and pH-sensitivity of the IPN hydrogel, increasing dose only decreased the swelling ratio. The PNIPAAm:CMCS=1:4 w/w hydrogel was not thermo-sensitive in distilled water, whereas it showed a discontinuous volume phase transition in pH 2 and a continuous one in pH 8 buffer. Consequently, a combination of pH and temperature can be coupled to control the responsive behavior of these hydrogels.

  5. Electroless plating of PVC plastic through new surface modification method applying a semi-IPN hydrogel film

    NASA Astrophysics Data System (ADS)

    Wang, Ming-Qiu; Yan, Jun; Du, Shi-Guo; Li, Hong-Guang

    2013-07-01

    A novel palladium-free surface activation process for electroless nickel plating was developed. This method applied a semi-Interpenetrating Polymer Network (semi-IPN) hydrogel film to modify the poly(vinyl chloride) (PVC) surface by chemical bonds. The activation process involved the formation of semi-IPN hydrogel film on the PVC surface and the immobilization of catalyst for electroless plating linking to the pretreated substrate via Nsbnd Ni chemical bond. The hydrogel layer was used as the chemisorption sites for nickel ions, and the catalyst could initiate the subsequent electroless nickel plating onto the PVC surface. Finally, a Ni-P layer was deposited on the nickel-activated PVC substrate by electroless plating technique. The composition and morphology of nickel-plated PVC foils were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The results of SEM and XRD show that a compact and continuous Ni-P layer with amorphous nickel phase is formed on the PVC surface. EDS shows that the content of the nickel and the phosphorus in the deposits is 89.4 wt.% and 10.6 wt.%, respectively.

  6. The Gene Encoding Dihydroflavonol 4-Reductase Is a Candidate for the anthocyaninless Locus of Rapid Cycling Brassica rapa (Fast Plants Type)

    PubMed Central

    Wendell, Douglas L.; Vaziri, Anoumid; Shergill, Gurbaksh

    2016-01-01

    Rapid cycling Brassica rapa, also known as Wisconsin Fast Plants, are a widely used organism in both K-12 and college science education. They are an excellent system for genetics laboratory instruction because it is very easy to conduct genetic crosses with this organism, there are numerous seed stocks with variation in both Mendelian and quantitative traits, they have a short generation time, and there is a wealth of educational materials for instructors using them. Their main deficiency for genetics education is that none of the genetic variation in RCBr has yet been characterized at the molecular level. Here we present the first molecular characterization of a gene responsible for a trait in Fast Plants. The trait under study is purple/nonpurple variation due to the anthocyaninless locus, which is one of the Mendelian traits most frequently used for genetics education with this organism. We present evidence that the DFR gene, which encodes dihyroflavonol 4-reductase, is the candidate gene for the anthocyaninless (ANL) locus in RCBr. DFR shows complete linkage with ANL in genetic crosses with a total of 948 informative chromosomes, and strains with the recessive nonpurple phenotype have a transposon-related insertion in the DFR which is predicted to disrupt gene function. PMID:27548675

  7. The Gene Encoding Dihydroflavonol 4-Reductase Is a Candidate for the anthocyaninless Locus of Rapid Cycling Brassica rapa (Fast Plants Type).

    PubMed

    Wendell, Douglas L; Vaziri, Anoumid; Shergill, Gurbaksh

    2016-01-01

    Rapid cycling Brassica rapa, also known as Wisconsin Fast Plants, are a widely used organism in both K-12 and college science education. They are an excellent system for genetics laboratory instruction because it is very easy to conduct genetic crosses with this organism, there are numerous seed stocks with variation in both Mendelian and quantitative traits, they have a short generation time, and there is a wealth of educational materials for instructors using them. Their main deficiency for genetics education is that none of the genetic variation in RCBr has yet been characterized at the molecular level. Here we present the first molecular characterization of a gene responsible for a trait in Fast Plants. The trait under study is purple/nonpurple variation due to the anthocyaninless locus, which is one of the Mendelian traits most frequently used for genetics education with this organism. We present evidence that the DFR gene, which encodes dihyroflavonol 4-reductase, is the candidate gene for the anthocyaninless (ANL) locus in RCBr. DFR shows complete linkage with ANL in genetic crosses with a total of 948 informative chromosomes, and strains with the recessive nonpurple phenotype have a transposon-related insertion in the DFR which is predicted to disrupt gene function. PMID:27548675

  8. Direct observation of the phase space footprint of a painting injection in the Rapid Cycling Synchrotron at the Japan Proton Accelerator Research Complex

    NASA Astrophysics Data System (ADS)

    Saha, P. K.; Shobuda, Y.; Hotchi, H.; Hayashi, N.; Takayanagi, T.; Harada, H.; Irie, Y.

    2009-04-01

    The 3 GeV Rapid Cycling Synchrotron (RCS) at Japan Proton Accelerator Research Complex is nearly at the operational stage with regard to the beam commissioning aspects. Recently, the design painting injection study has been commenced with the aim of high output beam power at the extraction. In order to observe the phase space footprint of the painting injection, a method was developed utilizing a beam position monitor (BPM) in the so-called single pass mode. The turn-by-turn phase space coordinates of the circulating beam directly measured using a pair of BPMs entirely positioned in drift space, and the calculated transfer matrices from the injection point to the pair of BPMs with several successive turns were used together in order to obtain the phase space footprint of the painting injection. There are two such pairs of BPMs placed in two different locations in the RCS, the results from which both agreed and were quite consistent with what was expected.

  9. Teaching Human Genetics with Mustard: Rapid Cycling Brassica rapa (Fast Plants Type) as a Model for Human Genetics in the Classroom Laboratory

    PubMed Central

    Pickard, Dawn

    2007-01-01

    We have developed experiments and materials to model human genetics using rapid cycling Brassica rapa, also known as Fast Plants. Because of their self-incompatibility for pollination and the genetic diversity within strains, B. rapa can serve as a relevant model for human genetics in teaching laboratory experiments. The experiment presented here is a paternity exclusion project in which a child is born with a known mother but two possible alleged fathers. Students use DNA markers (microsatellites) to perform paternity exclusion on these subjects. Realistic DNA marker analysis can be challenging to implement within the limitations of an instructional lab, but we have optimized the experimental methods to work in a teaching lab environment and to maximize the “hands-on” experience for the students. The genetic individuality of each B. rapa plant, revealed by analysis of polymorphic microsatellite markers, means that each time students perform this project, they obtain unique results that foster independent thinking in the process of data interpretation. PMID:17548880

  10. Estrous cycle variations in GABA(A) receptor phosphorylation enable rapid modulation by anabolic androgenic steroids in the medial preoptic area.

    PubMed

    Oberlander, J G; Porter, D M; Onakomaiya, M M; Penatti, C A A; Vithlani, M; Moss, S J; Clark, A S; Henderson, L P

    2012-12-13

    Anabolic androgenic steroids (AAS), synthetic testosterone derivatives that are used for ergogenic purposes, alter neurotransmission and behaviors mediated by GABA(A) receptors. Some of these effects may reflect direct and rapid action of these synthetic steroids at the receptor. The ability of other natural allosteric steroid modulators to alter GABA(A) receptor-mediated currents is dependent upon the phosphorylation state of the receptor complex. Here we show that phosphorylation of the GABA(A) receptor complex immunoprecipitated by β(2)/β(3) subunit-specific antibodies from the medial preoptic area (mPOA) of the mouse varies across the estrous cycle; with levels being significantly lower in estrus. Acute exposure to the AAS, 17α-methyltestosterone (17α-MeT), had no effect on the amplitude or kinetics of inhibitory postsynaptic currents in the mPOA of estrous mice when phosphorylation was low, but increased the amplitude of these currents from mice in diestrus, when it was high. Inclusion of the protein kinase C (PKC) inhibitor, calphostin, in the recording pipette eliminated the ability of 17α-MeT to enhance currents from diestrous animals, suggesting that PKC-receptor phosphorylation is critical for the allosteric modulation elicited by AAS during this phase. In addition, a single injection of 17α-MeT was found to impair an mPOA-mediated behavior (nest building) in diestrus, but not in estrus. PKC is known to target specific serine residues in the β(3) subunit of the GABA(A) receptor. Although phosphorylation of these β(3) serine residues showed a similar profile across the cycle, as did phosphoserine in mPOA lysates immunoprecipitated with β2/β3 antibody (lower in estrus than in diestrus or proestrus), the differences were not significant. These data suggest that the phosphorylation state of the receptor complex regulates both the ability of AAS to modulate receptor function in the mPOA and the expression of a simple mPOA-dependent behavior through a

  11. Rapid High Spatial Resolution Chemical Characterization of Soil Structure to Illuminate Nutrient Distribution Mechanisms Related to Carbon Cycling Using Laser Ablation Aerosol Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Hicks, R. K.; Alexander, M. L. L.; Newburn, M. K.

    2015-12-01

    Soils contain approximately half of Earth's terrestrial carbon. As such, it is important to understand the factors that control the cycling of this soil organic carbon between the land and the atmosphere. Models that attribute the persistence of soil organic carbon to the intrinsic properties of the molecules themselves are inconsistent with recent observations— for example, materials that are more thermodynamically stable have been found to have a shorter lifetime in soils than ones that are less stable, and vice versa. A new explanation has therefore been posited that invokes ecosystem properties as a whole, and not just intrinsic molecular properties, as the kinetic factor controlling soil carbon dynamics. Because soil dynamics occur on a small scale, techniques with high spatial resolution are required for their study. Existing techniques such as TOF-SIMS require preparation of the sample and introduction into a high vacuum system, and do not address the need to examine large numbers of sample systems without perturbation of chemical and physical properties. To address this analytical challenge, we have coupled a laser ablation (LA) module to an Aerodyne aerosol mass spectrometer (AMS), thereby enabling sample introduction and subsequent measurement of small amounts of soil organic matter by the laser ablation aerosol mass spectrometer (LA-AMS). Due to the adjustable laser beam width, the LA-AMS can probe spot sizes ranging from 1-150 μm in diameter, liberating from 10-100 ng/pulse. With a detection limit of 1 pM, the AMS allows for chemical characterization of the ablated material in terms of elemental ratios, compound classes, and TOC/TOM ratios. Furthermore, the LA-AMS is capable of rapid, in-situ sampling under ambient conditions, thereby eliminating the need for sample processing or transport before analysis. Here, we will present the first results from systematic studies aimed at validating the LA-AMS method as well as results from initial measurements

  12. Yield and seed oil content response of dwarf, rapid-cycling Brassica to nitrogen treatments, planting density, and carbon dioxide enrichment

    NASA Technical Reports Server (NTRS)

    Frick, J.; Nielsen, S. S.; Mitchell, C. A.

    1994-01-01

    Effects of N level (15 to 30 mM), time of N increase (14 to 28 days after planting), and planting density (1163 to 2093 plants/m2) were determined for crop yield responses of dwarf, rapid-cycling brassica (Brassica napus L., CrGC 5-2, Genome: ACaacc). Crops were grown in solid-matrix hydroponic systems and under controlled-environment conditions, including nonsupplemented (ambient) or elevated CO2 concentrations (998 +/- 12 micromoles mol-1). The highest seed yield rate obtained (4.4 g m-2 day-1) occurred with the lowest N level (15 mM) applied at the latest treatment time (day 28). In all trials, CO2 enrichment reduced seed yield rate and harvest index by delaying the onset of flowering and senescence and stimulating vegetative shoot growth. The highest shoot biomass accumulation rate (55.5 g m-2 day-1) occurred with the highest N level (30 mM) applied at the earliest time (day 14). Seed oil content was not significantly affected by CO2 enrichment. Maximum seed oil content (30% to 34%, dry weight basis) was obtained using the lowest N level (15 mM) initiated at the latest treatment time (day 28). In general, an increase in seed oil content was accompanied by a decrease in seed protein. Seed carbohydrate, moisture, and ash contents did not vary significantly in response to experimental treatments. Effects of N level and time of N increase were consistently significant for most crop responses. Planting density was significant only under elevated CO2 conditions.

  13. Predictors of Non-Stabilization during the Combination Therapy of Lithium and Divalproex in Rapid Cycling Bipolar Disorder: A Post-hoc Analysis of Two Studies

    PubMed Central

    Gao, Keming; Kemp, David E.; Wang, Zuowei; Ganocy, Stephen J.; Conroy, Carla; Serrano, Marry Beth; Sajatovic, Martha; Findling, Robert L.; Calabrese, Joseph R.

    2012-01-01

    Objective To study predictors of non–stabilization (i.e., not bimodally stabilized for randomization or not randomized due to premature discontinuation) during open-label treatment with lithium and divalproex in patients with rapid-cycling bipolar disorder (RCBD) with or without comorbid recent substance use disorders (SUDs). Method Data from the open-label phase of two maintenance studies were used. The reasons for non-stabilization were compared between patients with a recent SUD and those without. Predictors for non-stabilization were explored with logistic regression analyses. Results Of 149 patients with recent SUD and 254 without recent SUD enrolled into the open-label acute stabilization phase, 21% and 24% were stabilized and randomized, respectively. Compared to those without recent SUD, patients with recent SUD were more likely to discontinue the study due to non-adherence to the protocol, 53% versus 37% (OR = 1.92) or refractory mania/hypomania, 15% versus 9% (OR = 1.87), but less likely due to refractory depression 16% versus 25% (OR = 0.58) or adverse events, 10% versus 19% (OR = 0.44). A history of recent SUDs, early life verbal abuse, female gender, and late onset of first depressive episode were associated with increased risk for non-stabilization with ORs of 1.85, 1.74, 1.10, and 1.04, respectively. Conclusions During open treatment with lithium and divalproex in patients with RCBD, a recent SUD, a lifetime history of verbal abuse, female gender, and late onset of first depression independently predicted non-stabilization. The non-stabilization for patients with SUD was related to non-adherence and refractory mania/hypomania. PMID:20581798

  14. The coenzyme A disulfide reductase of Borrelia burgdorferi is important for rapid growth throughout the enzootic cycle and essential for infection of the mammalian host

    PubMed Central

    Eggers, Christian H.; Caimano, Melissa J.; Malizia, Robert A.; Kariu, Toru; Cusack, Brian; Desrosiers, Daniel C.; Hazlett, Karsten R.O.; Claiborne, Al; Pal, Utpal; Radolf, Justin D.

    2011-01-01

    Summary In a microarray analysis of the RpoS regulon in mammalian host-adapted Borrelia burgdorferi, bb0728 (cdr) was found to be dually-transcribed by the sigma factors σ70 and RpoS. The cdr gene encodes a coenzyme A disulfide reductase (CoADR) that reduces CoA-disulfides to CoA in an NADH-dependent manner. Based on the abundance of CoA in B. burgdorferi and the biochemistry of the enzyme, CoADR has been proposed to play a role in the spirochete’s response to reactive oxygen species (ROS). To better understand the physiologic function(s) of Bb CoADR, we generated a B. burgdorferi mutant in which the cdr gene was disrupted. RT-PCR and 5′-RACE analysis revealed that cdr and bb0729 are co-transcribed from a single transcriptional start site upstream of the bb0729 coding sequence; a shuttle vector containing the bb0729-cdr operon and upstream promoter element was used to complement the cdr mutant. Although the mutant was no more sensitive to hydrogen peroxide than its parent, it did exhibit increased sensitivity to high concentrations of t -butyl-hydroperoxide, an oxidizing compound that damages spirochetal membranes. Characterization of the mutant during standard (15% oxygen, 6% CO2) and anaerobic (<1% O2, 9–13% CO2) cultivation at 37°C revealed a growth defect under both conditions that was particularly striking during anaerobiosis. The mutant was avirulent by needle inoculation and showed decreased survival in feeding nymphs, but displayed no survival defect in unfed flat nymphs. Based on these results, we propose that Bb CoADR is necessary to maintain optimal redox ratios for CoA/CoA-disulfide and NAD+/NADH during periods of rapid replication throughout the enzootic cycle, to support thiol-disulfide homeostasis, and to indirectly protect the spirochete against peroxide-mediated membrane damage; one or more of these functions are essential for infection of the mammalian host by B. burgdorferi. PMID:21923763

  15. pH- and Temperature-Responsive P(DMAEMA-GMA)-Alginate Semi-IPN Hydrogels Formed by Radical and Ring-Opening Polymerization for Aminophylline Release.

    PubMed

    Gao, Chunmei; Liu, Mingzhu; Chen, Jun; Chen, Chen

    2012-01-01

    A novel poly((2-dimethylamino) ethyl methacrylate-glycidyl methacrylate)-alginate (P(DMAEMA-GMA)alginate) semi-IPN hydrogel was synthesized via radical polymerization of the double bonds and ring-opening of the epoxy groups without using catalyst and cross-linker. (1)H-NMR, FT-IR and DSC data were consistent with the expected structures for the hydrogels. The interior morphology of the hydrogels was also investigated by SEM. The swelling ratio and compressive strength of the hydrogels were measured. The semi-IPN hydrogel had pH and temperature sensitivity, and pH-sensitive points of all hydrogels were found to be at pH 5.0. The release behavior of the model drug, aminophylline, was found to be dependent on the hydrogel composition and environment pH, which manifests that these materials have potential applications as intelligent drug carriers. PMID:21513583

  16. Electric field responsive chitosan-poly(N,N-dimethyl acrylamide) semi-IPN gel films and their dielectric, thermal and swelling characterization

    NASA Astrophysics Data System (ADS)

    Sarmad, Shokat; Yenici, Gökçen; Gürkan, Koray; Keçeli, Gönül; Gürdaǧ, Gülten

    2013-05-01

    The electroresponsive, dielectric and swelling behavior of semi-interpenetrated polymer network (semi-IPN) gel films prepared from chitosan (CS) and N,N-dimethyl acrylamide (DA) were investigated and compared with those CS film. CS-DA semi-IPN films were also characterized by Fourier transform infrared, x-ray diffraction and differential scanning calorimetry measurements. The electrosensitivity of CS-DA films to an electric field was investigated by determining their bending at 8 V in (0.05 M/0.1 M/0.15 M) NaCl solution. Equilibrium swelling values of CS-DA films both in distilled water and buffer solution with pH = 2.2 decreased with poly-DA (PDA) content of the films. While the maximum decomposition of CS film took place at about 296 °C, the presence of PDA in CS-DA semi-IPN films reduced the thermal stability, and their maximum decomposition temperature shifted from 261 to 240 °C with the increase in PDA content. In addition, the PDA network led to a decrease in the dielectric constant (ɛ‧), dielectric loss (ɛ″) and conductance (σ) of CS-DA semi-IPN films in the frequency range between 12 Hz and 100 kHz. The values of electric modulus and impedance, and Cole-Cole plots confirmed that the conductance values of CS-DA films are lower than that of CS film. The PDA network also led CS-DA films to respond more slowly to electric field. The increase in NaCl concentration in the bending medium increased the response rate of CS-DA films to an electric field. The final bending angle of all CS-DA films was 90°, and it was not dependent on either NaCl concentration or PDA content of the films.

  17. Stimuli-responsive coacervate induced in binary functionalized poly(N-isopropylacrylamide) aqueous system and novel method for preparing semi-ipn microgel using the coacervate.

    PubMed

    Maeda, Tomohiro; Akasaki, Yusuke; Yamamoto, Kazuya; Aoyagi, Takao

    2009-08-18

    We describe a novel method for preparing a stimuli-responsive semi-interpenetrating polymer network (semi-IPN) hydrogel microsphere using a thermoresponsive-type coacervation. The coacervate droplets were formed in the two-component nonionic poly(N-isopropylacrylamide-co-2-hydroxyisopropylacrylamide) (poly(NIPAAm-co-HIPAAm)) and ionic poly(NIPAAm-co-2-carboxyisopropylacrylamide) (poly(NIPAAm-co-CIPAAm)) aqueous system by heating the solution above the lower critical solution temperature. The resulting coacervate droplets included both kinds of polymer chains. Divinyl sulfone, which cross-links the hydroxyl groups of the poly(NIPAAm-co-HIPAAm), was added to the coacervate droplets. In this way, the stimuli-responsive semi-IPN hydrogel microsphere consisting of the poly(NIPAAm-co-HIPAAm) gel matrix and the linear poly(NIPAAm-co-CIPAAm) chains could be prepared, and their sizes were relatively homogeneous. That is, by utilizing the thermoresponsive coacervate droplets induced in the binary system, we could successfully prepare the fine stimuli-responsive semi-IPN hydrogel microsphere and it was prepared in a simple and easy method without any additives. PMID:19492785

  18. Preparation and properties of a pH/temperature-responsive carboxymethyl chitosan/poly(N-isopropylacrylamide)semi-IPN hydrogel for oral delivery of drugs.

    PubMed

    Guo, Bao-Lin; Gao, Qing-Yu

    2007-11-26

    Thermo- and pH-responsive semi-IPN polyampholyte hydrogels were prepared by using carboxymethylchitosan and poly(N-isopropylacrylamide) with N,N'-methylenebisacrylamide (BIS) as the crosslinking agent. The swelling characteristics of these hydrogels at distinct compositions as a function of pH and temperature were investigated. It was found that the semi-IPN hydrogels demonstrated the pH- and temperature-responsive nature of the materials, and it also showed good reversibility. The study on the release of coenzyme A (CoA) showed that within 24h the cumulative release ratio of CoA was 22.6% in pH 2.1 solution and 89.1% in pH 7.4 solution at 37 degrees C, respectively. The release rate of CoA was higher at 37 degrees C than 25 degrees C in a pH 7.4 buffer solution. An increased release rate of CoA was observed with the content of carboxymethylchitosan increasing in the hydrogel at 25 degrees C in pH 7.4 solution. These results show that semi-IPN hydrogel seems to be of great promise in pH-temperature oral drug delivery systems. PMID:17669378

  19. Drug release of pH/temperature-responsive calcium alginate/poly(N-isopropylacrylamide) semi-IPN beads.

    PubMed

    Shi, Jun; Alves, Natália M; Mano, João F

    2006-05-23

    A series of semi-interpenetrating, polymer network (semi-IPN), hydrogel beads, composed of calcium alginate (Ca-alginate) and poly(N-isopropylacrylamide) (PNIPAAM), were prepared for a pH/temperature-sensitive drug delivery study. The equilibrium swelling showed the independent pH- and thermo- responsive nature of the developed materials. At pH=2.1, the release amount of indomethacin incorporated into these beads was about 10% within 400 min, while this value approached to 95% at pH=7.4. The release rate of the drug was higher at 37 degrees C than that at 25 degrees C and increased slightly with increasing PNIPAAM content. These results suggest that the Ca-alginate/PNIPAAM beads have the potential to be used as an effective pH/temperature sustainable delivery system of bioactive agents. [GRAPHS: SEE TEXT] A summary of the temperature- and pH-dependence on the release of the drug over a period of 450 min. The effect of the temperature on the swelling of the beads is shown in the inset. PMID:16671051

  20. Thermoresponsive hyperbranched copolymer with multi acrylate functionality for in situ cross-linkable hyaluronic acid composite semi-IPN hydrogel.

    PubMed

    Dong, Yixiao; Hassan, Waqar; Zheng, Yu; Saeed, Aram Omer; Cao, Hongliang; Tai, Hongyun; Pandit, Abhay; Wang, Wenxin

    2012-01-01

    Thermoresponsive polymers have been widely used for in situ formed hydrogels in drug delivery and tissue engineering as they are easy to handle and their shape can easily conform to tissue defects. However, non-covalent bonding and mechanical weakness of these hydrogels limit their applications. In this study, a physically and chemically in situ cross-linkable hydrogel system was developed from a novel thermoresponsive hyperbranched PEG based copolymer with multi acrylate functionality, which was synthesized via an 'one pot and one step' in situ deactivation enhanced atom transfer radical co-polymerization of poly(ethylene glycol) diacrylate (PEGDA, M(n) = 258 g mol(-1)), poly(ethylene glycol) methyl ether methacrylate (PEGMEMA, M(n )= 475 g mol(-1)) and (2-methoxyethoxy) ethyl methacrylate (MEO(2)MA). This hyperbranched copolymer was tailored to have the lower critical solution temperature to form physical gelation around 37°C. Meanwhile, with high level of acrylate functionalities, a chemically cross-linked gel was formed from this copolymer using thiol functional cross-linker of pentaerythritol tetrakis (3-mercaptopropionate) (QT) via thiol-ene Michael addition reaction. Furthermore, a semi-interpenetrated polymer networks (semi-IPN) structure was developed by combining this polymer with hyaluronic acid (HA), leading to an in situ cross-linkable hydrogel with significantly increased porosity, enhanced swelling behavior and improved cell adhesion and viability both in 2D and 3D cell culture models. PMID:22143908

  1. Rapid and Specific Detection of Amantadine-Resistant Influenza A Viruses with a Ser31Asn Mutation by the Cycling Probe Method▿

    PubMed Central

    Suzuki, Yasushi; Saito, Reiko; Zaraket, Hassan; Dapat, Clyde; Caperig-Dapat, Isolde; Suzuki, Hiroshi

    2010-01-01

    Amantadine is one of the antiviral agents used to treat influenza A virus infections, but resistant strains have widely emerged worldwide. In the present study, we developed a novel method to detect amantadine-resistant strains harboring the Ser31Asn mutation in the M2 gene based on the cycling probe method and real-time PCR. We also studied the rate of amantadine resistance in the 2007-2008 influenza season in Japan. Two different primer and cycling probe sets were designed for A/H1N1 and A/H3N2 each to detect a single nucleotide polymorphism corresponding to Ser/Asn at residue 31 of the M2 protein. By using nasopharyngeal swabs from patients with influenza-like and other respiratory illnesses and virus isolates, the specificity and the sensitivity of the cycling probe method were evaluated. High frequencies of amantadine resistance were detected among the A/H1N1 (411/663, 62%) and A/H3N2 (56/56, 100%) virus isolates collected from six prefectures in Japan in the 2007-2008 influenza season. We confirmed that the cycling probe method is suitable for the screening of both nasopharyngeal swabs and influenza virus isolates for amantadine-resistant strains and showed that the incidence of amantadine resistance among both A/H1N1 and A/H3N2 viruses remained high in Japan during the 2007-2008 season. PMID:19889895

  2. Safety and efficacy of pegfilgrastim compared to granulocyte colony stimulating factor (G-CSF) supporting a dose-intensive, rapidly cycling anti-metabolite containing chemotherapy regimen (Hyper-CVAD) for lymphoid malignancy.

    PubMed

    Lane, Steven W; Crawford, Julie; Kenealy, Melita; Cull, Gavin; Seymour, John F; Prince, H Miles; Marlton, Paula; Gill, Devinder; Mollee, Peter N

    2006-09-01

    Pegfilgrastim (Neulasta) has proven efficacy as supportive therapy in a variety of 21-day chemotherapy regimens, but has not been studied in dose intensive, rapidly cycling regimens utilising cell-cycle active drugs (e.g. anti-metabolites) such as hyper-CVAD. This study examined whether pegfilgrastim was safe and lead to similar kinetics of neutrophil recovery as daily granulocyte colony stimulating factor (G-CSF). Using retrospective analysis, patients receiving pegfilgrastim (6 mg) were matched with controls (G-CSF 5 microg kg-1 per day) for a cycle of chemotherapy, prior chemotherapy, dose of cytarabine received, age (<60 or >60 years), diagnosis and bone marrow involvement. The primary endpoint was duration of grade IV neutropenia (absolute neutrophil count, ANC < 500 microl-1). Secondary endpoints included time to neutrophil recovery, incidence of febrile neutropenia, positive blood cultures and delay in subsequent chemotherapy. This study identified 124 pegfilgrastim supported cycles in 43 patients and successfully matched them to 124 G-CSF supported cycles from 38 patients treated between January 1999 and July 2005. There were no significant differences between pegfilgrastim and G-CSF groups in baseline or treatment-related variables. The median duration of grade IV neutropenia was 4 days in both groups (P = 0.55). Time to neutrophil recovery, incidence of febrile neutropenia, positive blood cultures and delay in subsequent chemotherapy were similar in both groups. Once per cycle dosing of pegfilgrastim appears safe and as effective as daily G-CSF for supporting the hyper-CVAD chemotherapy regimen. PMID:17064993

  3. Rapid and large-scale synthesis of bare Co3O4 porous nanostructures from an oleate precursor as superior Li-ion anodes with long-cycle lives.

    PubMed

    Ge, Danhua; Wu, Junjie; Qu, Genlong; Deng, Yaoyao; Geng, Hongbo; Zheng, Junwei; Pan, Yue; Gu, Hongwei

    2016-09-14

    In this study, we describe a rapid and environmentally friendly synthesis of bare Co3O4 nanocrystals derived from Co(ii) oleate complexes by calcination treatment. When directly used as anode materials for lithium-ion batteries (LIBs), the as-prepared nanocrystals could deliver a high reversible capacity of 980 mA h g(-1) after 250 cycles at a current density of 100 mA g(-1) and excellent cycling performance, which may be beneficial to promote the further development of the next generation of lithium ion batteries. The synthetic route can offer great advantages for the flash preparation of other metal oxide nanocrystals for energy storage application. PMID:27503555

  4. A rapid and robust assay for detection of S-phase cell cycle progression in plant cells and tissues by using ethynyl deoxyuridine

    PubMed Central

    2010-01-01

    Background Progress in plant cell cycle research is highly dependent on reliable methods for detection of cells replicating DNA. Frequency of S-phase cells (cells in DNA synthesis phase) is a basic parameter in studies on the control of cell division cycle and the developmental events of plant cells. Here we extend the microscopy and flow cytometry applications of the recently developed EdU (5-ethynyl-2'-deoxyuridine)-based S-phase assay to various plant species and tissues. We demonstrate that the presented protocols insure the improved preservation of cell and tissue structure and allow significant reduction in assay duration. In comparison with the frequently used detection of bromodeoxyuridine (BrdU) and tritiated-thymidine incorporation, this new methodology offers several advantages as we discuss here. Results Applications of EdU-based S-phase assay in microscopy and flow cytometry are presented by using cultured cells of alfalfa, Arabidopsis, grape, maize, rice and tobacco. We present the advantages of EdU assay as compared to BrdU-based replication assay and demonstrate that EdU assay -which does not require plant cell wall digestion or DNA denaturation steps, offers reduced assay duration and better preservation of cellular, nuclear and chromosomal morphologies. We have also shown that fast and efficient EdU assay can also be an efficient tool for dual parameter flow cytometry analysis and for quantitative assessment of replication in thick root samples of rice. Conclusions In plant cell cycle studies, EdU-based S-phase detection offers a superior alternative to the existing S-phase assays. EdU method is reliable, versatile, fast, simple and non-radioactive and it can be readily applied to many different plant systems. PMID:20181034

  5. P(AAm-co-MAA) semi-IPN hybrid hydrogels in the presence of PANI and MWNTs-COOH: improved swelling behavior and mechanical properties.

    PubMed

    Liu, Zhanqing; Luo, Yanling; Zhang, Kaipu

    2008-01-01

    A highly pH-sensitive hybrid hydrogel with semi-interpenetrating networks (semi-IPN)composed of co-polymer networks of acrylamide-methacrylic acid (P(AAm-co-MAA)) and polyaniline (PANI)/carboxyl-functionalized multi-walled carbon nanotubes (MWNTs-COOH) was designed and synthesized by a cross-linking co-polymerization route in the presence of N,N-methylene bisacrylamide (BIS) and ammonium persulfate (APS). The structural and morphological characterization and mechanical properties of the gels were investigated using a Equinx55 FT-IR spectrometer, an environmental scanning electron microscope and a dynamical viscoelasticity analyzer, respectively. Swelling capability of the hybrid hydrogels was examined under the conditions of various pH buffer solutions (1.35, 6.95 and 12.86) at a temperature of 27 degrees C. P(AAm-co-MAA) co-polymer hydrogels were discussed as a control sample at the same time. The experimental results indicated that the prepared P(AAm-co-MAA) co-polymer hydrogels showed a high equilibrium swelling ratio in distilled water, pH-responsive characteristics and excellent strain recoverability. After having incorporated the polyelectrolyte PANI and MWNTs-COOH into the above-mentioned network, the P(AAm-co-MAA)/PANI/MWNTs-COOH semi-IPN hybrid hydrogels obtained possessed an even higher sensitivity to pH environments, good swelling reversibility, higher ultimate compressive strength and good strain recoverable ability. Swelling experimentations in buffer solutions of different pH revealed that the semi-IPN hybrid hydrogels possessed higher tensile strengths at a lower pH than at a higher pH value. All the excellent properties may primarily be attributed to the formation and weakening or disappearance of a repulsive force based on hydrogen bonds, as well as appearance of attractive forces of pole-pole interactions between PANI chains at different pH values. PMID:18973726

  6. Rapid onset of nucleolar disintegration preceding cell cycle arrest in roscovitine-induced apoptosis of human MCF-7 breast cancer cells.

    PubMed

    Wojciechowski, Jacek; Horky, Marcel; Gueorguieva, Marieta; Wesierska-Gadek, Józefa

    2003-09-10

    The aim of our study was to explore the antiproliferative and pro-apoptotic action of roscovitine (ROSC) on human breast cancer MCF-7 cells. We examined the effect of ROSC on cell proliferation, cell cycle progression, nucleolar morphology, posttranslational modifications of histones as well as on induction of apoptosis. The effects of ROSC on the argyrophilic nucleolar organizer regions (AgNORs) and nucleolar RNA of MCF-7 cells were marked: ROSC treatment changed the pattern of AgNORs in a time-dependent manner. The disintegration of nucleoli manifested by increasing number of nucleolar fragments already began at 6 hr posttreatment. This was accompanied by a redistribution of the nucleolin from the nucleolus beginning after 6 hr and preceded a decrease of histone acetylation and phosphorylation. Inhibition of DNA synthesis and accumulation of G(2)/M-arrested cells starting 6 hr posttreatment coincided with a strong increase of the p53 level and with an appearance of a few cells committed to undergo apoptosis. However, all these changes preceded the main wave of apoptosis, which occurred after 24 hr ROSC treatment as assessed by determination of the frequency of Annexin binding, activation of caspases as well as of DNA fragmentation. Onset of PARP-1 cleavage detected by immunoblotting and by immunohistochemistry 6 hr or 9 hr posttreatment, respectively, preceded for a few hours the DNA fragmentation detected in situ by TUNEL assay. Reconstitution of MCF-7 cells with caspase-3 did not change the kinetics of ROSC-induced apoptosis. Our results show that disintegration of nucleoli is an early marker of ROSC-induced changes. Cell cycle arrest precedes the main wave of apoptosis. PMID:12845642

  7. Transient Rapid Changes in Nutrient Cycling at the Onset of Terrestrial Colonization by Rooted Plants in the Devonian Caithness Flagstone Group, Orkney Islands

    NASA Astrophysics Data System (ADS)

    Filippelli, G. M.; Beshears, M.; Whiteside, J. H.

    2012-12-01

    these events is transient—barring other changes in erosion, the release/retention fluxes of these elements tends toward a steady state. Nevertheless, these results support a flush of the bio-limiting nutrient P into the ocean at the onset of terrestrial colonization by rooting plants which might have temporarily increased global marine productivity, thus impacting carbon cycling and climate.; Modeled transformations in terrestrial P cycling during incipient soil development

  8. Carbon cycling in a rapidly changing High Arctic: Results from long-term climate experiments and observations of interannual variability in NW Greenland

    NASA Astrophysics Data System (ADS)

    Czimczik, C. I.; Lupascu, M.; Csank, A. Z.; Seibt, U. H.; Maseyk, K. S.; Xu, X.; Welker, J. M.

    2013-12-01

    The High Arctic, a region dominated by polar semi-deserts underlain with continuous permafrost, is experiencing dramatic changes in climate associated with the loss of sea ice, including warming and shifts in precipitation regimes (i.e. wetting and changing snow cover). Here, we present findings from a set of studies that are addressing the sign and strength of the High Arctic's summertime carbon (C) cycle feedback. We explored magnitudes, patterns and sources of C losses through CO2 and CH4 fluxes and via leaching as dissolved organic C (DOC) and particulate organic C (POC) along with measurements of net ecosystem exchange and plant C uptake. From studying long-term summertime experimental warming and/or watering and interannual weather patterns we find that in polar semi-deserts: a) Summer precipitation regime is the key driver of current summertime C budgets. Warming plus wetting results in increased ecosystem C sequestration and reduced losses of older C as CO2, while warming alone decreases C uptake and increases losses of older soil C as CO2. The system is a sink for CH4, but the sink strength will decline with increasing soil moisture. Thus, the High Arctic has the potential to remain a strong summertime C sink even as the rest of the permafrost region transitions to a net C source to the atmosphere as climate continues to warm. b) Old C is diffusing out of the High Arctic landscape into the atmosphere. This C loss is especially evident in the spring before vegetation pumps fresh C into the soil system. Further, loss of older C from the deeper active layer is highly episodic and dominates C emissions during small precipitation events. c) Precipitation regime is also the key driver of that ancient C export from the land surface as DOC, higher precipitation in the later part of the growing season (July-August), when the active layer is deeper, results in a greater fraction of old C transported to the nearshore Arctic Ocean. Collectively these findings

  9. Rapid changes and long-term cycles in the benthic megafaunal community observed over 24 years in the abyssal northeast Pacific

    NASA Astrophysics Data System (ADS)

    Kuhnz, Linda A.; Ruhl, Henry A.; Huffard, Christine L.; Smith, Kenneth L.

    2014-05-01

    The abyssal seafloor community in the NE Pacific (Station M, ∼4000 m depth) was studied between 2006 and 2012 using remotely operated vehicles (ROVs) as part of a continuing 24-year time-series study. New patterns continue to emerge showing that the deep-sea can be dynamic on short time scales, rather than static over long periods. In just over 2 years the community shifted from a sessile, suspension-feeding, sponge-dominated community to a mobile, detritus-feeding, sea cucumber-dominated assemblage. In 2006 megafaunal diversity (Simpson’s Diversity Index, SDI) was high, yet the community was depauperate in terms of density compared to later periods. Over an 18-month period beginning in spring 2011, the densities of mobile organisms increased by nearly an order of magnitude while diversity decreased below 2006 levels. In late 2012 four sea cucumbers (two Peniagone spp., Elpidia sp. A, and Scotoplanes globosa) were at the highest densities recorded since investigations began at Station M in 1989. For a group of 10 echinoderms investigated over the entire study period, we saw evidence of a long-term cycle spanning 2 decades. These changes can be tied to a variable food supply originating in shallow water. Large variations over decadal-scales indicate that remote abyssal communities are dynamic and likely subject to impacts from anthropogenic changes like ocean warming, acidification, and pollution manifested in the upper ocean. The degree of dynamism indicates that one-time or short-term investigations are not sufficient for assessing biological community structure in conservation or exploitation studies in the deep sea.

  10. Up-cycling waste glass to minimal water adsorption/absorption lightweight aggregate by rapid low temperature sintering: optimization by dual process-mixture response surface methodology.

    PubMed

    Velis, Costas A; Franco-Salinas, Claudia; O'Sullivan, Catherine; Najorka, Jens; Boccaccini, Aldo R; Cheeseman, Christopher R

    2014-07-01

    Mixed color waste glass extracted from municipal solid waste is either not recycled, in which case it is an environmental and financial liability, or it is used in relatively low value applications such as normal weight aggregate. Here, we report on converting it into a novel glass-ceramic lightweight aggregate (LWA), potentially suitable for high added value applications in structural concrete (upcycling). The artificial LWA particles were formed by rapidly sintering (<10 min) waste glass powder with clay mixes using sodium silicate as binder and borate salt as flux. Composition and processing were optimized using response surface methodology (RSM) modeling, and specifically (i) a combined process-mixture dual RSM, and (ii) multiobjective optimization functions. The optimization considered raw materials and energy costs. Mineralogical and physical transformations occur during sintering and a cellular vesicular glass-ceramic composite microstructure is formed, with strong correlations existing between bloating/shrinkage during sintering, density and water adsorption/absorption. The diametrical expansion could be effectively modeled via the RSM and controlled to meet a wide range of specifications; here we optimized for LWA structural concrete. The optimally designed LWA is sintered in comparatively low temperatures (825-835 °C), thus potentially saving costs and lowering emissions; it had exceptionally low water adsorption/absorption (6.1-7.2% w/wd; optimization target: 1.5-7.5% w/wd); while remaining substantially lightweight (density: 1.24-1.28 g.cm(-3); target: 0.9-1.3 g.cm(-3)). This is a considerable advancement for designing effective environmentally friendly lightweight concrete constructions, and boosting resource efficiency of waste glass flows. PMID:24871934

  11. Thermochemical cycles

    NASA Technical Reports Server (NTRS)

    Funk, J. E.; Soliman, M. A.; Carty, R. H.; Conger, W. L.; Cox, K. E.; Lawson, D.

    1975-01-01

    The thermochemical production of hydrogen is described along with the HYDRGN computer program which attempts to rate the various thermochemical cycles. Specific thermochemical cycles discussed include: iron sulfur cycle; iron chloride cycle; and hybrid sulfuric acid cycle.

  12. Rapid heparin-sensitive Ca2+ release following Ca(2+)-ATPase inhibition in intact HL-60 granulocytes. Evidence for Ins(1,4,5)P3-dependent Ca2+ cycling across the membrane of Ca2+ stores.

    PubMed Central

    Favre, C J; Lew, D P; Krause, K H

    1994-01-01

    In many cell types, emptying of intracellular Ca2+ stores after application of inhibitors of the intracellular Ca(2+)-ATPase (e.g. thapsigargin) is astonishingly rapid. It was the aim of this study to elucidate the underlying mechanism. We first compared thapsigargin-induced emptying of intracellular Ca2+ stores in intact and homogenized HL-60 granulocytes. Thapsigargin-induced Ca2+ release was rapid in intact cells (33.9 +/- 4.9% of store content/min), but it was slow in permeabilized or homogenized cells (7.7 +/- 3.9 and 12 +/- 3.8% of store content/min respectively). To study whether the Ins(1,4,5)P3 receptor might be involved in thapsigargin-induced Ca2+ release, we tested the effect of heparin, a competitive Ins(1,4,5)P3 antagonist. In homogenized and permeabilized preparations, heparin did not interfere with thapsigargin-induced Ca2+ release. In contrast, when introduced into intact cells by an endocytosis/osmotic-shock procedure, heparin, but not the inactive de-N-sulphated heparin, decreased the rate of Ca2+ release by approx. 70%. Heparin inhibited Ca2+ release in response to the Ins(1,4,5)P3-generating receptor agonist N-formylmethionyl-leucyl-phenylalanine (f-MLP) (50 nM) and to thapsigargin (50 nM) at comparable concentrations. Heparin inhibition was competitive for f-MLP-induced, but not for thapsigargin-induced, Ca2+ release. In permeabilized cells, the addition of low Ins(1,4,5)P3 concentrations before thapsigargin increased the rate of thapsigargin-induced Ca2+ release 4-fold. Taken together, our results suggest that the rapid Ca(2+)-ATPase-inhibitor-induced Ca2+ release is due to a partial activation of the Ins(1,4,5)P3 receptor in resting cells. This implies Ca2+ cycling across the membrane of Ins(1,4,5)P3-sensitive Ca2+ stores in resting cells. Images Figure 7 PMID:8068001

  13. Beam loss caused by edge focusing of injection bump magnets and its mitigation in the 3-GeV rapid cycling synchrotron of the Japan Proton Accelerator Research Complex

    NASA Astrophysics Data System (ADS)

    Hotchi, H.; Tani, N.; Watanabe, Y.; Harada, H.; Kato, S.; Okabe, K.; Saha, P. K.; Tamura, F.; Yoshimoto, M.

    2016-01-01

    In the 3-GeV rapid cycling synchrotron of the Japan Proton Accelerator Research Complex, transverse injection painting is utilized not only to suppress space-charge induced beam loss in the low energy region but also to mitigate foil scattering beam loss during charge-exchange injection. The space-charge induced beam loss is well minimized by the combination of modest transverse painting and full longitudinal painting. But, for sufficiently mitigating the foil scattering part of beam loss, the transverse painting area has to be further expanded. However, such a wide-ranging transverse painting had not been realized until recently due to beta function beating caused by edge focusing of pulsed injection bump magnets during injection. This beta function beating additionally excites random betatron resonances through a distortion of the lattice superperiodicity, and its resultant deterioration of the betatron motion stability causes significant extra beam loss when expanding the transverse painting area. To solve this issue, we newly installed pulse-type quadrupole correctors to compensate the beta function beating. This paper presents recent experimental results on this correction scheme for suppressing the extra beam loss, while discussing the beam loss and its mitigation mechanisms with the corresponding numerical simulations.

  14. Effect of substituting Ni with Cu on the cycle stability of La{sub 0.7}Mg{sub 0.3}Ni{sub 2.55-x}Co{sub 0.45}Cu {sub x} (x = 0-0.4) electrode alloy prepared by casting and rapid quenching

    SciTech Connect

    Ren Huiping; Zhang Yanghuan . E-mail: zyh59@yahoo.com.cn; Li, Bao-wei; Dong Xiaoping; Zhao Xiaolong; Wang Xinlin

    2007-03-15

    In order to improve the cycle stability of the La-Mg-Ni system (PuNi{sub 3}-type) hydrogen storage alloy, Ni in the alloy was partly substituted by Cu. Hydrogen storage alloys La{sub 0.7}Mg{sub 0.3}Ni{sub 2.55-x}Co{sub 0.45}Cu {sub x} (x = 0, 0.1, 0.2, 0.3, 0.4) were prepared by casting and rapid quenching. The effects of substituting Ni with Cu and the quenching rate on the microstructures and the cycle stability of the as-cast and quenched alloys were investigated in detail. The results obtained by X-ray diffraction show that the as-cast and quenched alloys have a multiphase structure, including the (La, Mg)Ni{sub 3} phase, the LaNi{sub 5} phase and the LaNi{sub 2} phase, and the amount of the LaNi{sub 2} phase increased with the increase of the Cu content. The substitution and rapid quenching have an inappreciable influence on the phase compositions of the alloys, but both obviously changed the phase abundances of the alloys. The results derived by transmission electron microscopy confirm that the substitution of Cu for Ni is favourable for the formation of an amorphous phase in the as-quenched alloys. The results obtained by the electrochemical measurement indicate that substituting Ni with Cu improved the cycle stability. When the Cu content increases from 0 to 0.4, the cycle lives of the as-cast and rapidly solidified alloys increased from 72 cycles to 88 cycles and from 100 cycles to 122 cycles, respectively.

  15. Responsiveness and Release Characteristic of Semi-IPN Hydrogels Consisting of Nano-Sized Clay Crosslinked Poly(Dimethylaminoethyl Methacrylate) and Linear Carboxymethyl Chitosan.

    PubMed

    Chen, Yi; Peng, Chang; Lu, Yanbing; Liu, Wenyong; Xu, Weijian

    2015-01-01

    PH and temperature double responsive semi-IPN hydrogels consisting of poly(dimethylaminoethyl methacrylate) (PDMAEMA) network crosslinked by nano-sized inorganic clay and linear carboxymethyl chitosan (CMCS) were synthesized by in situ, free radical polymerization in aqueous solution. The effect of the mass and carboxymethyl substitution of CMCS on the responsiveness, swelling/deswelling and drug release characteristic of gels were investigated. Comparing to the gels without CMCS, the resulting gels (named as C-NC gels) showed similar LCST and temperature response behavior. However, with the increase of added CMCS, the swelling ratio of gels decreased considerably around the isoelectric point (IEP) of CMCS, while increased in both strong acidic and alkaline condition. The deswelling rate was improved significantly when the content of CMCS is high. In drug load and release test by using theophylline as target, the C-NC gels exhibited an excellent load ability and controlled-release in simulated human intestinal and stomachic condition. Additionally, all properties of gels were affected by the DS of added CMCS due to the different ratio and interaction of negative and positive ions in gels. PMID:26328322

  16. A 3D Porous Gelatin-Alginate-Based-IPN Acts as an Efficient Promoter of Chondrogenesis from Human Adipose-Derived Stem Cells

    PubMed Central

    Jianu, Dana; Tumbar, Tudorita

    2015-01-01

    Cartilage has limited regeneration potential. Thus, there is an imperative need to develop new strategies for cartilage tissue engineering (CTE) amenable for clinical use. Recent CTE approaches rely on optimal cell-scaffold interactions, which require a great deal of optimization. In this study we attempt to build a novel gelatin- (G-) alginate- (A-) polyacrylamide (PAA) 3D interpenetrating network (IPN) with superior performance in promoting chondrogenesis from human adipose-derived stem cells (hADSCs). We show that our G-A-PAA scaffold is capable of supporting hADSCs proliferation and survival, with no apparent cytotoxic effect. Moreover, we find that after exposure to prochondrogenic conditions a key transcription factor known to induce chondrogenesis, namely, Sox9, is highly expressed in our hADSCs/G-A-PAA bioconstruct, along with cartilage specific markers such as collagen type II, CEP68, and COMP extracellular matrix (ECM) components. These data suggest that our G-A-PAA structural properties and formulation might enable hADSCs conversion towards functional chondrocytes. We conclude that our novel G-A-PAA biomatrix is a good candidate for prospective in vivo CTE applications. PMID:26106422

  17. Fragile cycles

    NASA Astrophysics Data System (ADS)

    Bonatti, Ch.; Díaz, L. J.

    We study diffeomorphisms f with heterodimensional cycles, that is, heteroclinic cycles associated to saddles p and q with different indices. Such a cycle is called fragile if there is no diffeomorphism close to f with a robust cycle associated to hyperbolic sets containing the continuations of p and q. We construct a codimension one submanifold of Diff(S×S) that consists of diffeomorphisms with fragile heterodimensional cycles. Our construction holds for any manifold of dimension ⩾4.

  18. Rapid Environmental Fluctuations Recorded over the Last Glacial/Interglacial Cycle in the Sediments from Borehole PRGL1-4 (Gulf of Lions; Western Mediterranean) using Radiogenic Isotopes (Sr & Nd)

    NASA Astrophysics Data System (ADS)

    Nizou, J.

    2015-12-01

    The study of sediments deposited and preserved in oceanic basins unable us to examine how terrigenous sediment supply varied through time in relation to paleoenvironmental and climatic changes on land. The geochemical and isotopic compositions of marine sediment are used to unravel its provenance, and provide information about its formation. Providing that the paleoclimatic frame is known, such data give an insight into the rock-source location and allow us to decipher between genetic processes of mechanical erosion and chemical alteration. Borehole PRGL1-4 (European project PROMESS), located in the Gulf of Lions (W Mediterranean) at 300 mwd, was investigated geochemically at high-temporal resolution over the last glacial/interglacial cycle (i.e. 130 ka) to study sediment-source variations during rapid climate changes. Besides, sediments originating from the Rhône's and the Pyreneo-Languedocian's catchment areas have been analyzed to measure the isotopic composition of five source end-members that are the Alps, the Higher Rhône valley, the Lower Rhône valley, the Languedoc and the Pyrenees. Epsilon Nd and 87Sr/86Sr were measured on 60 samples encompassing 4 marine isotopic stages with an emphasis on Heinrich events. The epsilon Nd values of PRGL1-4 lean towards the Lower Rhône valley unradiogenic end-member during cold stadial intervals, and towards the Alpine radiogenic end-member during warm interstadials. The presence of an ice cap over the crystalline Alpine watershed during cold phases could prevent the sediments originating from this region from reaching the Gulf of Lions. The same pattern is observed during the time of Heinrich events. An influence of the sea level variations on the sedimentation at the borehole site during the Heinrich events is unlikely since they are only 10 to 15 m in amplitude. Furthermore, a major isotopic shift in epsilon Nd mean values is displayed around 40 ka that coincides with the connection of the Durance to the Rhône River

  19. Menstrual Cycle

    MedlinePlus

    ... Pregnancy This information in Spanish ( en español ) The menstrual cycle Day 1 starts with the first day of ... drop around Day 25 . This signals the next menstrual cycle to begin. The egg will break apart and ...

  20. Rapid climate change

    SciTech Connect

    Morantine, M.C.

    1995-12-31

    Interactions between insolation changes due to orbital parameter variations, carbon dioxide concentration variations, the rate of deep water formation in the North Atlantic and the evolution of the northern hemisphere ice sheets during the most recent glacial cycle will be investigated. In order to investigate this period, a climate model is being developed to evaluate the physical mechanisms thought to be most significant during this period. The description of the model sub-components will be presented. The more one knows about the interactions between the sub-components of the climate system during periods of documented rapid climate change, the better equipped one will be to make rational decisions on issues related to impacts on the environment. This will be an effort to gauge the feedback processes thought to be instrumental in rapid climate shifts documented in the past, and their potential to influence the current climate. 53 refs.

  1. Rapid Prototyping

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Javelin, a Lone Peak Engineering Inc. Company has introduced the SteamRoller(TM) System as a commercial product. The system was designed by Javelin during a Phase II NASA funded small commercial product. The purpose of the invention was to allow automated-feed of flexible ceramic tapes to the Laminated Object Manufacturing rapid prototyping equipment. The ceramic material that Javelin was working with during the Phase II project is silicon nitride. This engineered ceramic material is of interest for space-based component.

  2. Biodegradable nano-micro carrier systems for sustained pulmonary drug delivery: (I) Self-assembled nanoparticles encapsulated in respirable/swellable semi-IPN microspheres

    PubMed Central

    El-Sherbiny, I. M.; Smyth, H. D. C.

    2012-01-01

    Design of appropriate inhaled carriers with adequate aerodynamic properties, drug release, biodegradation and evasion of macrophage uptake is a major challenge for controlled release pulmonary drug delivery. In this study, PEG graft copolymerized onto N-phthaloyl chitosan (NPHCs) was synthesized then characterized using FTIR, EA, DSC and 2D-XRD. The resulting PEG-g-NPHCs copolymers were self-assembled into drug loaded nanoparticles and encapsulated in respirable/swellable sodium alginate semi-IPN hydrogel microspheres as novel biodegradable carriers for controlled release pulmonary drug delivery. The developed nano-/microspheres carrier systems were formed via spray drying followed by ionotropic crosslinking in mild aqueous medium. The size of the developed self-assembled nanoparticles and the microspheres was measured using dynamic light scattering and laser diffraction, respectively. Morphology, moisture content, in-vitro biodegradation and dynamic swelling studies were also investigated for the developed carriers. A model protein was entrapped and the in-vitro release profiles were determined in PBS, pH 7.4 at 37°C. A dry powder aerosolization study was conducted using a Next Generation Impactor (NGI). The developed microspheres had suitable aerodynamic diameters (1.02–2.63 μm) and an excellent fine particle fraction, FPF of 31.52%. The microspheres showed also a very fast initial swelling within the first 2 min and started to enzymatically degrade within the first two hours. Moreover, the microspheres entrapped up 90% of the model drug and showed promising in-vitro sustained release profiles as compared to the control formulation. PMID:20580794

  3. Metal ion-induced alginate-locust bean gum IPN microspheres for sustained oral delivery of aceclofenac.

    PubMed

    Jana, Sougata; Gandhi, Arijit; Sheet, Subrata; Sen, Kalyan Kumar

    2015-01-01

    The alginate microspheres represent a useful tool for sustained oral delivery of drugs but exhibit several problems associated with the stability and rapid release of drugs at higher pH values. To overcome these drawbacks, alginate-locust bean gum (LBG) interpenetrating microspheres were prepared by calcium ion (Ca(+2)) induced ionotropic gelation technique for prolonged release of aceclofenac. The drug entrapment efficiency of these microspheres was found to be 59-93%. The microspheres lied in the size range of 406-684μm. Scanning electron microscopy revealed spherical shape of the microspheres. No drug-polymer interaction was evident after infrared spectroscopy analysis. The microspheres provided sustained release of aceclofenac in phosphate buffer solution (pH 6.8) over a period of 8h. The drug release data were fitted into the Korsmeyer-Peppas model and the drug release was found to follow anomalous (non-Fickian) diffusion mechanism. Pharmacodynamic study of the microspheres showed a prolonged anti-inflammatory activity in carrageenan-induced rat paw model following oral administration. PMID:25111495

  4. The Chlamydomonas Cell Cycle

    PubMed Central

    Cross, Frederick R.; Umen, James G.

    2015-01-01

    The position of Chlamydomonas within the eukaryotic phylogeny makes it a unique model in at least two important ways: as a representative of the critically important, early-diverging lineage leading to plants, and as a microbe retaining important features of the last eukaryotic common ancestor (LECA) that have been lost in the highly studied yeast lineages. Its cell biology has been studied for many decades, and it has well-developed experimental genetic tools, both classical (Mendelian) and molecular. Unlike land plants, it is a haploid with very few gene duplicates, making it ideal for loss-of-function genetic studies. The Chlamydomonas cell cycle has a striking temporal and functional separation between cell growth and rapid cell divisions, probably connected to the interplay between diurnal cycles that drive photosynthetic cell growth with the cell division cycle; it also exhibits a highly choreographed interaction between the cell cycle and its centriole/basal body/flagellar cycle. Here we review the current status of studies of the Chlamydomonas cell cycle. We begin with an overview of cell cycle control in the well-studied yeast and animal systems, which has yielded a canonical, well-supported model. We discuss briefly what is known about similarities and differences in plant cell cycle control compared to this model. We next review the cytology and cell biology of the multiple fission cell cycle of Chlamydomonas. Lastly we review recent genetic approaches and insights into Chlamydomonas cell cycle regulation that have been enabled by a new generation of genomics-based tools. PMID:25690512

  5. Solar Cycle Predictions

    NASA Technical Reports Server (NTRS)

    Pesnell, William Dean

    2012-01-01

    Solar cycle predictions are needed to plan long-term space missions; just like weather predictions are needed to plan the launch. Fleets of satellites circle the Earth collecting many types of science data, protecting astronauts, and relaying information. All of these satellites are sensitive at some level to solar cycle effects. Predictions of drag on LEO spacecraft are one of the most important. Launching a satellite with less propellant can mean a higher orbit, but unanticipated solar activity and increased drag can make that a Pyrrhic victory as you consume the reduced propellant load more rapidly. Energetic events at the Sun can produce crippling radiation storms that endanger all assets in space. Solar cycle predictions also anticipate the shortwave emissions that cause degradation of solar panels. Testing solar dynamo theories by quantitative predictions of what will happen in 5-20 years is the next arena for solar cycle predictions. A summary and analysis of 75 predictions of the amplitude of the upcoming Solar Cycle 24 is presented. The current state of solar cycle predictions and some anticipations how those predictions could be made more accurate in the future will be discussed.

  6. [Rapid PCR authentication Lonicera japanica].

    PubMed

    Jiang, Chao; Hou, Jing-Yi; Huang, Lu-Qi; Yuan, Yuan; Chen, Min; Jin, Yan

    2014-10-01

    To simply and rapid authenticate Lonicera japanica. Rapid allele-specific PCR primer was designed base on trnL-trnF 625 G/T Single nucleotide polymorphism and the PCR reaction systems including annealing temperature was optimized; optimized results were performed to authenticate L. japanica and its 9 adulterants. When 100 x SYBR Green I was added in the PCR product of 87 degrees C initial denatured 1 min; 87 degrees C denatured 5 s, 68 degrees C annealing 5 s, 30 cycle; L. japanica visualize strong green fluorescence under 365 nm UV lamp whereas adulterants without. The results indicate rapid allele-specific PCR could authenticate L. japanica and its adulterants rapidly and simply. PMID:25612418

  7. Cycle Analysis

    Energy Science and Technology Software Center (ESTSC)

    2012-03-20

    1. The Cycle Analysis code is an Microsoft Excel code that performs many different types of thermodynamic cycle analysis for power producing systems. The code will calculate the temperature and pressure and all other thermodynamic properties at the inlet and outlet of each component. The code also calculates the power that is produced, the efficiency, and the heat transported in the heater, gas chiller and recuperators. The code provides a schematic of the loop andmore » provides the temperature and pressure at each location in the loop. The code also provides a T-S (temperature-entropy) diagram of the loop and often it provides an pressure enthalpy plot as well. 2. This version of the code concentrates on supercritical CO2 power cycles, but by simply changing the name of the working fluid many other types of fluids can be analyzed. The Cycle Analysis code provided here contains 18 different types of power cycles. Each cycle is contained in one worksheet or tab that the user can select. The user can change the yellow highlighted regions to perform different thermodynamic cycle analysis.« less

  8. Solid state rapid thermocycling

    SciTech Connect

    Beer, Neil Reginald; Spadaccini, Christopher

    2014-05-13

    The rapid thermal cycling of a material is targeted. A solid state heat exchanger with a first well and second well is coupled to a power module. A thermoelectric element is coupled to the first well, the second well, and the power module, is configured to transfer thermal energy from the first well to the second well when current from the power module flows through the thermoelectric element in a first direction, and is configured to transfer thermal energy from the second well to the first well when current from the power module flows through the thermoelectric element in a second direction. A controller may be coupled to the thermoelectric elements, and may switch the direction of current flowing through the thermoelectric element in response to a determination by sensors coupled to the wells that the amount of thermal energy in the wells falls below or exceeds a pre-determined threshold.

  9. Cycling injuries.

    PubMed Central

    Cohen, G. C.

    1993-01-01

    Bicycle-related injuries have increased as cycling has become more popular. Most injuries to recreational riders are associated with overuse or improper fit of the bicycle. Injuries to racers often result from high speeds, which predispose riders to muscle strains, collisions, and falls. Cyclists contact bicycles at the pedals, seat, and handlebars. Each is associated with particular cycling injuries. Images Figure 1 Figure 3 Figure 4 Figure 5 PMID:8471908

  10. Nutrient cycling.

    PubMed

    Bormann, F H; Likens, G E

    1967-01-27

    The small-watershed approach to problems of nutrient cycling has these advantages. (i) The small watershed is a natural unit of suitable size for intensive study of nutrient cycling at the ecosystem level. (ii) It provides a means of reducing to a minimum, or virtually eliminating, the effect of the difficult-to-measure variables of geologic input and nutrient losses in deep seepage. Control of these variables makes possible accurate measurement of nutrient input and output (erosion) and therefore establishes the relationship of the smaller ecosystem to the larger biospheric cycles. (iii) The small-watershed approach provides a method whereby such important parameters as nutrient release from minerals (weathering) and annual nutrient budgets may be calculated. (iv) It provides a means of studying the interrelationships between the biota and the hydrologic cycle, various nutrient cycles, and energy flow in a single system. (v) Finally, with the small-watershed system we can test the effect of various land-management practices or environmental pollutants on nutrient cycling in natural systems. PMID:17737551