Science.gov

Sample records for active gain medium

  1. Active medium gain study of electric-discharge oxygen-iodine laser

    NASA Astrophysics Data System (ADS)

    Kolobyanin, Yuriy; Adamenkov, Yuriy; Vyskubenko, Boris; Goryachev, Leonid; Ilyin, Sergey; Kalashnik, Anatoliy; Rakhimova, Tatiana; Rogozhnikov, Georgiy

    2007-05-01

    The paper reports on experimental studies of the active medium gain in supersonic electric-discharge oxygen-iodine laser (DOIL) based on traveling mw discharge. The measurements have included: absolute concentration, yield, and energy efficiency of production of SO in pure oxygen and oxygen-helium mixes at an oxygen partial pressure 3 to 15 Torr. For the gas flow to get rid of atomic oxygen, both heterogeneous mercury oxide coatings of the tube walls and homogeneous additives to the work mix, such as nitrogen oxide, have been used. The active medium of DOIL was formed using a nozzle array of the type of ejector sized as 10*50 mm2. The singlet oxygen-helium mix was supplied through three rows of sonic cylindrical nozzles, while the iodine-carrier gas mix - through two rows of supersonic conical nozzles with a half-opening angle of 10°(arc). The gas-phase iodine was produced in a quartz cell filled with iodine crystals. Room-temperature iodine vapors were picked up with a carrier gas (nitrogen or helium) and thus delivered into the nozzle array. The active medium was investigated by the high-resolution laser diode spectroscopy approach that used the laser type Vortex 6025 purchased from New Focus, Inc. The laser medium gain factor was determined by the intra-cavity approach having a sensitivity about 1*10 -6 cm -1. The static temperature of the medium was determined from the measurements of gain half-width. The gain of the active medium of electric-discharge OIL has been investigated. The DOIL in use was operating on a mix composed as O II:He=1:1 at a total pressure of 6 Torr and flowrate - about 1 mmol/s. With helium as an iodine carrier gas at a flowrate ~3 mmol/s, we have recorded a positive gain in the DOIL medium.

  2. All-optical transistor using a photonic-crystal cavity with an active Raman gain medium

    NASA Astrophysics Data System (ADS)

    Arkhipkin, V. G.; Myslivets, S. A.

    2013-09-01

    We propose a design of an all-optical transistor based on a one-dimensional photonic-crystal cavity doped with a four-level N-type active Raman gain medium. The calculated results show that in a photonic-crystal cavity of this kind transmission and reflection of the probe (Raman) beam are strongly dependent on the optical switching power. Transmission and reflection of the probe beam can be greatly amplified or attenuated. Therefore the optical switching field can serve as a gate field of the transistor to effectively control propagation of the weak probe field. It is shown that the group velocity of the probe pulse can be controlled in the range from subluminal (slow light) to superluminal (fast light).

  3. FBG sensor system based on wavelength-swept active mode-locking laser with RSOA gain medium

    NASA Astrophysics Data System (ADS)

    Kim, Hyo-jin; Lee, Hwi Don; Jeong, Myong Yung; Kim, Chang-Seok; Lee, Ju Han

    2011-05-01

    We performed an experiment of wavelength-swept laser based on active mode-locking on reflective semiconductor optical amplifier (RSOA). Since this laser does not have a wavelength-selecting filter, it can achieve a high sweeping speed and reduce the component cost and size. Compared to the conventional SOA gain medium, RSOA shows a merit of higher efficiency of cross gain modulation due to the twice propagation of active gain region. We applied this laser to Fiber Bragg grating (FBG) strain sensor system which can have faster data acquisition speed than conventional wavelength-swept laser method. The linear response of FBG peak for the applied strain is monitored using the proposed laser source.

  4. Linear and nonlinear Faraday rotations of light polarization in a four-level active-Raman-gain medium

    NASA Astrophysics Data System (ADS)

    Zhu, Chengjie; Deng, L.; Hagley, E. W.

    2013-08-01

    We investigate linear and nonlinear Faraday effects in a room-temperature, coherently driven four-level active-Raman-gain (ARG) medium. By using the multiple-scale method, we derive two nonlinear coupled envelope equations governing the dynamics of left- and right-polarized components of a linearly polarized probe field. Under the weak probe field approximation, we demonstrate a factor of four increase of the Faraday rotation angle by the linear and nonlinear response of the ARG scheme without probe field loss. We further compare this ARG system with an M-type five-state electromagnetically induced transparency (EIT) scheme and demonstrate the superiority of the ARG scheme over the conventional EIT scheme.

  5. Microwave gain medium with negative refractive index

    NASA Astrophysics Data System (ADS)

    Ye, Dexin; Chang, Kihun; Ran, Lixin; Xin, Hao

    2014-12-01

    Artificial effective media are attractive because of the fantastic applications they may enable, such as super lensing and electromagnetic invisibility. However, the inevitable loss due to their strongly dispersive nature is one of the fundamental challenges preventing such applications from becoming a reality. In this study, we demonstrate an effective gain medium based on negative resistance, to overcompensate the loss of a conventional passive metamaterial, meanwhile keeping its original negative-index property. Energy conservation-based theory, full-wave simulation and experimental measurement show that a fabricated sample consisting of conventional sub-wavelength building blocks with embedded microwave tunnel diodes exhibits a band-limited Lorentzian dispersion simultaneously with a negative refractive index and a net gain. Our work provides experimental evidence to the assertion that a stable net gain in negative-index gain medium is achievable, proposing a potential solution for the critical challenge current metamateiral technology faces in practical applications.

  6. Highly entangled photons and rapidly responding polarization qubit phase gates in a room-temperature active Raman gain medium

    SciTech Connect

    Hang Chao; Huang Guoxiang

    2010-11-15

    We present a scheme for obtaining entangled photons and quantum phase gates in a room-temperature four-state tripod-type atomic system with two-mode active Raman gain (ARG). We analyze the linear and nonlinear optical responses of this ARG system and show that the scheme is fundamentally different from those based on electromagnetically induced transparency and hence can avoid significant probe-field absorption as well as a temperature-related Doppler effect. We demonstrate that highly entangled photon pairs can be produced and rapidly responding polarization qubit phase gates can be constructed based on the unique features of the enhanced cross-phase-modulation and superluminal probe-field propagation of the system.

  7. A laser gyro with a four-mirror square resonator: quantitative estimation of the dependence of the synchronisation zone parameters of the frequencies of counterpropagating waves on the active-medium gain

    SciTech Connect

    Bondarenko, Evgenii A

    2012-05-31

    For a laser gyro with a four-mirror square resonator (with a perimeter of 20 cm) we have calculated, on the basis of the previously developed [see Bondarenko E.A. Quantum Electron., 41, 824 (2011)] model, the dependence of the parameters of the synchronisation zone of the frequencies of counterpropagating waves on the active-medium gain. The results obtained are in qualitative agreement with known experimental data for gyroscopes with three-mirror resonators.

  8. Multipolar, time-dynamical model for the loss compensation and lasing of a spherical plasmonic nanoparticle spaser immersed in an active gain medium.

    PubMed

    Veltri, Alessandro; Chipouline, Arkadi; Aradian, Ashod

    2016-01-01

    The plasmonic response of a metal nanoparticle in the presence of surrounding gain elements is studied, using a space and time-dependent model, which integrates a quantum formalism to describe the gain and a classical treatment for the metal. Our model fully takes into account the influence of the system geometry (nanosphere) and offers for the first time, the possibility to describe the temporal evolution of the fields and the coupling among the multipolar modes of the particle. We calculate the lasing threshold value for all multipoles of the spaser, and demonstrate that the dipolar one is lowest. The onset of the lasing instability, in the linear regime, is then studied both with and without external field forcing. We also study the behaviour of the system below the lasing threshold, with the external field, demonstrating the existence of an amplification regime where the nanoparticle's plasmon is strongly enhanced as the threshold is approached. Finally, a qualitative discussion is provided on later, non-linear stages of the dynamics and the approach to the steady-state of the spaser; in particular, it is shown that, for the considered geometry, the spasing is necessarily multi-modal and multipolar modes are always activated. PMID:27625072

  9. Measurements of the gain medium temperature in an operating Cs DPAL.

    PubMed

    Zhdanov, B V; Rotondaro, M D; Shaffer, M K; Knize, R J

    2016-08-22

    A Mach-Zehnder interferometer was used for contactless measurement of the temperature of the gain medium within a static cell of Cs DPAL. The maximum temperature recorded approached 700° C leading to a significant degradation of laser performance. This work also examined lasing and non-lasing heat deposition and has shown that as much as 85% of the heating in a DPAL gain medium can be attributed to quenching. PMID:27557208

  10. Thickness optimization of the composite gain medium for the oscillator and amplifier of the lucia laser.

    PubMed

    Yu, Haiwu; Bourdet, Gilbert

    2005-11-20

    Using a theory of quasi-three-level laser ions, we obtained the optimum thickness of the gain medium of Yb:YAG. For the parameters of the oscillator and the amplifier of the diode-pumped Lucia laser (Lasers Ultra-Courts et Intense et Applications), which will deliver a 100 J, 10 Hz, 10 ns pulse train the optimum thicknesses are, respectively, 1.4 and 1.6 mm, with a concentration of 10 at. %. Simulations indicate that the bending of such a thin medium is great but can be eliminated by substitution of a composite gain medium. The optimum thickness of undoped YAG is related to that of Yb:YAG and is also dependent on cooling conditions. Results show that, for a small-aperture oscillator, we can obtain both minimum bending and optical distortion at several doping concentrations. However, greater doping (approximately 20 at. %) is preferred for a large-aperture amplifier. The results reported will be helpful for the design of gain media for high-average-power thin disk Yb:YAG lasers. PMID:16320442

  11. Influence of wave-packet dynamics on the medium gain of an atomic system

    SciTech Connect

    Delagnes, J. C.; Bouchene, M. A.

    2007-10-15

    A sequence of two femtosecond pulses--a strong driving {pi}-polarized pulse and a weak propagating {sigma}-polarized pulse--excites resonantly the S{sub 1/2}{yields}P{sub 1/2} transition of an atomic system. Strong interference effects take place in the system between absorption and emission paths leading to a substantial amplification of the {sigma} pulse. We study the influence of the fine structure on the medium gain when the contribution of the off-resonant P{sub 3/2} level is taken into account. A drastic reduction of the medium gain is obtained. This effect is explained within the bright-state-dark-state formalism where the strong driving pulse creates a wave packet that can be trapped in a state--the bright state--leading to a significant reduction of the gain for the {sigma} pulse. Finally, we also show that periodical gain dependence with the driving pulse energy exhibits a significant change in its period value (compared with expected Rabi oscillations)

  12. High Average Power Laser Gain Medium With Low Optical Distortion Using A Transverse Flowing Liquid Host

    DOEpatents

    Comaskey, Brian J.; Ault, Earl R.; Kuklo, Thomas C.

    2005-07-05

    A high average power, low optical distortion laser gain media is based on a flowing liquid media. A diode laser pumping device with tailored irradiance excites the laser active atom, ion or molecule within the liquid media. A laser active component of the liquid media exhibits energy storage times longer than or comparable to the thermal optical response time of the liquid. A circulation system that provides a closed loop for mixing and circulating the lasing liquid into and out of the optical cavity includes a pump, a diffuser, and a heat exchanger. A liquid flow gain cell includes flow straighteners and flow channel compression.

  13. Gainful Activity and Intimate Partner Aggression in Emerging Adulthood*

    PubMed Central

    Alvira-Hammond, Marta; Longmore, Monica A.; Manning, Wendy D.; Giordano, Peggy C.

    2014-01-01

    Although intimate partner aggression crosses social class boundaries, education and income are important predictors. Yet given that emerging adulthood is a transitional period, completed education and employment, as single measures, are not ideal indicators of socioeconomic status for young people. We examined associations between self-reports of gainful activity, defined as enrollment in school or full-time employment, and intimate partner aggression among young adults in dating, cohabiting, or married relationships (N=648). Both men and women's participation in gainful activity was negatively associated with aggression. We found that when neither partner was gainfully active, individuals reported higher frequency of physical aggression. In cases of gainful activity asymmetry, the gender of the gainfully active partner did not predict intimate partner aggression. Additionally, we found no evidence that the association between gainful activity and frequency of intimate partner aggression differed by union type. PMID:25309829

  14. Analytical solution of the transient temperature profile in gain medium of passively Q-switched microchip laser.

    PubMed

    Han, Xiahui; Li, Jianlang

    2014-11-01

    The transient temperature evolution in the gain medium of a continuous wave (CW) end-pumped passively Q-switched microchip (PQSM) laser is analyzed. By approximating the time-dependent population inversion density as a sawtooth function of time and treating the time-dependent pump absorption of a CW end-pumped PQSM laser as the superposition of an infinite series of short pumping pulses, the analytical expressions of transient temperature evolution and distribution in the gain medium for four- and three-level laser systems, respectively, are given. These analytical solutions are applied to evaluate the transient temperature evolution and distribution in the gain medium of CW end-pumped PQSM Nd:YAG and Yb:YAG lasers. PMID:25402922

  15. Photonuclear activation of pure isotopic mediums.

    SciTech Connect

    Grohman, Mark A.; Lukosi, Eric Daniel

    2010-06-01

    This work simulated the response of idealized isotopic U-235, U-238, Th-232, and Pu-239 mediums to photonuclear activation with various photon energies. These simulations were conducted using MCNPX version 2.6.0. It was found that photon energies between 14-16 MeV produce the highest response with respect to neutron production rates from all photonuclear reactions. In all cases, Pu-239 responds the highest, followed by U-238. Th-232 produces more overall neutrons at lower photon energies then U-235 when material thickness is above 3.943 centimeters. The time it takes each isotopic material to reach stable neutron production rates in time is directly proportional to the material thickness and stopping power of the medium, where thicker mediums take longer to reach stable neutron production rates and thinner media display a neutron production plateau effect, due to the lack of significant attenuation of the activating photons in the isotopic mediums. At this time, no neutron sensor system has time resolutions capable of verifying these simulations, but various indirect methods are possible and should be explored for verification of these results.

  16. The effect of gain medium length on dynamic mode stability in semiconductor lasers with a long intra-cavity filter.

    PubMed

    Kwon, Oh Kee; Lee, Chul Wook; Shin, Jang Wook; Sim, Eun Deok; Kim, Jong-Hoi; Lee, Dong Hun; Bang, Dong Soo; Baek, Yong Soon

    2009-12-01

    We investigate theoretically and experimentally the effect of the physical length of gain medium on dynamic mode stability in semiconductor lasers with an intra-cavity filter. In simulation, two types of analysis models were used to examine the lasing properties and to analyze the dynamic mode stability of the external-cavity system, respectively. In experiment, two different kinds of the structures were fabricated and their spectra were analyzed. Both simulation and measurement results show clearly the length of the gain medium has a critical influence on the stability around the peak wavelength of the filter. PMID:20052209

  17. Gain-adaptive vector quantization for medium-rate speech coding

    NASA Technical Reports Server (NTRS)

    Chen, J.-H.; Gersho, A.

    1985-01-01

    A class of adaptive vector quantizers (VQs) that can dynamically adjust the 'gain' of codevectors according to the input signal level is introduced. The encoder uses a gain estimator to determine a suitable normalization of each input vector prior to VQ coding. The normalized vectors have reduced dynamic range and can then be more efficiently coded. At the receiver, the VQ decoder output is multiplied by the estimated gain. Both forward and backward adaptation are considered and several different gain estimators are compared and evaluated. An approach to optimizing the design of gain estimators is introduced. Some of the more obvious techniques for achieving gain adaptation are substantially less effective than the use of optimized gain estimators. A novel design technique that is needed to generate the appropriate gain-normalized codebook for the vector quantizer is introduced. Experimental results show that a significant gain in segmental SNR can be obtained over nonadaptive VQ with a negligible increase in complexity.

  18. Lossless propagation in metal-semiconductor-metal plasmonic waveguides using quantum dot active medium.

    PubMed

    Sheikhi, K; Granpayeh, N; Ahmadi, V; Pahlavan, S

    2015-04-01

    In this paper, we analyze and simulate the lossless propagation of lightwaves in the active metal-semiconductor-metal plasmonic waveguides (MSMPWs) at the wavelength range of 1540-1560 nm using a quantum dot (QD) active medium. The Maxwell's equations are solved in the waveguide, and the required gains for achieving lossless propagation are derived. On the other hand, the rate equations in quantum dot active regions are solved by using the Runge-Kutta method, and the achievable optical gain is derived. The analyses results show that the required optical gain for lossless propagation in MSMPWs is achievable using the QD active medium. Also, by adjusting the active medium parameters, the MSMPWs loss can be eliminated in a specific bandwidth, and the propagation length increases obviously. PMID:25967191

  19. Enhanced optical precursors by Doppler effect via active Raman gain process.

    PubMed

    Peng, Yandong; Niu, Yueping; Zhang, Lida; Yang, Aihong; Jiang, Lin; Gong, Shangqing

    2012-08-15

    A scheme for enhancing precursor pulse by Doppler effect is proposed in a room-temperature active-Raman-gain medium. Due to abnormal dispersion between two gain peaks, main fields are advanced and constructively interfere with optical precursors, which leads to enhancement of the transient pulse at the rise edge of the input. Moreover, after Doppler averaging, the abnormal dispersion intensifies and the constructive interference between precursors and main fields is much strengthened, which boosts the transient spike. Simulation results demonstrate that the peak intensity of precursors could be enhanced nearly 20 times larger than that of the input. PMID:23381248

  20. Epigenetic memory gained by priming with osteogenic induction medium improves osteogenesis and other properties of mesenchymal stem cells

    PubMed Central

    Rui, Yunfeng; Xu, Liangliang; Chen, Rui; Zhang, Ting; Lin, Sien; Hou, Yonghui; Liu, Yang; Meng, Fanbiao; Liu, Zhenqing; Ni, Ming; Sze Tsang, Kam; Yang, Fuyuan; Wang, Chen; Chang Chan, Hsiao; Jiang, Xiaohua; Li, Gang

    2015-01-01

    Mesenchymal stem cells (MSCs) are highly plastic cells that are able to transdifferentiate or dedifferentiate under appropriate conditions. In the present study, we reported here that after in vitro induction of osteogenic differentiation, MSCs could be reverted to a primitive stem cell population (dedifferentiated osteogenic MSCs, De-Os-MSCs) with improved cell survival, colony formation, osteogenic potential, migratory capacity and increased expression of Nanog, Oct4 and Sox2. Most importantly, our results showed great superiority of the De-Os-MSCs over untreated MSCs in ectopic bone formation in vivo. Furthermore, Nanog-knockdown in MSCs could reverse these enhanced properties in De-Os-MSCs in vitro, indicating a central role of Nanog in the transcriptional network. In addition, epigenetic regulations including DNA methylation and histone modifications may play important roles in regulating the de-osteogenic differentiation process. And we found decreased methylation and promoter accrual of activating histone marks, such as H3K4me3 and H4ac on both Nanog and Oct4 gene promoters. Taken together, our study demonstrated that epigenetic memory in De-Os-MSCs gained by priming with osteogenic induction medium favored their differentiation along osteoblastic lineage with improved cell survival and migratory abilities, which may have application potential in enhancing their regenerative capacity in mammals. PMID:26053250

  1. 20 CFR 404.1510 - Meaning of substantial gainful activity.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Meaning of substantial gainful activity. 404.1510 Section 404.1510 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Definition of Disability §...

  2. 20 CFR 404.1510 - Meaning of substantial gainful activity.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Meaning of substantial gainful activity. 404.1510 Section 404.1510 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Definition of Disability §...

  3. 20 CFR 404.1510 - Meaning of substantial gainful activity.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Meaning of substantial gainful activity. 404.1510 Section 404.1510 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Definition of Disability §...

  4. 20 CFR 404.1510 - Meaning of substantial gainful activity.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Meaning of substantial gainful activity. 404.1510 Section 404.1510 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Definition of Disability §...

  5. 20 CFR 404.1510 - Meaning of substantial gainful activity.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Meaning of substantial gainful activity. 404.1510 Section 404.1510 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Definition of Disability §...

  6. 26 CFR 7.105-2 - Substantial gainful activity.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 14 2012-04-01 2012-04-01 false Substantial gainful activity. 7.105-2 Section 7.105-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX... because of a physical or mental impairment accepts sheltered employment in a protected environment...

  7. 26 CFR 7.105-2 - Substantial gainful activity.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 14 2010-04-01 2010-04-01 false Substantial gainful activity. 7.105-2 Section 7.105-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX... because of a physical or mental impairment accepts sheltered employment in a protected environment...

  8. 20 CFR 416.910 - Meaning of substantial gainful activity.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Meaning of substantial gainful activity. 416.910 Section 416.910 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Definition of Disability §...

  9. 20 CFR 416.910 - Meaning of substantial gainful activity.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Meaning of substantial gainful activity. 416.910 Section 416.910 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Definition of Disability §...

  10. 20 CFR 416.910 - Meaning of substantial gainful activity.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Meaning of substantial gainful activity. 416.910 Section 416.910 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Definition of Disability §...

  11. 20 CFR 416.910 - Meaning of substantial gainful activity.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Meaning of substantial gainful activity. 416.910 Section 416.910 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Definition of Disability §...

  12. 20 CFR 416.910 - Meaning of substantial gainful activity.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Meaning of substantial gainful activity. 416.910 Section 416.910 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Definition of Disability §...

  13. Magnetic plasmonic metamaterials in actively pumped host medium and plasmonic nanolaser

    NASA Astrophysics Data System (ADS)

    Sarychev, Andrey K.; Tartakovsky, Gennady

    2006-08-01

    We consider plasmonic nanoantennas immersed in active host medium. Specifically shaped metal nanoantennas can exhibit strong magnetic properties in the optical spectral range due to the excitation of Magnetic Resonance Plasmons (MRP). A case when a metamaterial comprising such nanoantennas can demonstrate both "left-handiness" and negative permeability in the optical range is considered. We show that high losses predicted for optical "left-handed" materials can be compensated in the gain medium. Gains required to achieve local generation in such magnetic active metamaterials are calculated for real metals

  14. Reduced polarization decay due to carrier in-scattering in a semiconductor active medium

    SciTech Connect

    Hughes, S.; Knorr, A.; Koch, S.W.; Chow, W.W.

    1996-07-01

    The in-scattering processes, which reduce the decay of the active medium polarization, should be included in a consistent treatment of semiconductor laser gain. The in-scattering processes affect the laser gain by decreasing the influence of the high k-states, which contribute absorption to the spectrum. A theory, based on the semiconductor-Bloch equations with the effects of carrier-carrier scattering treated at the level of the quantum kinetic equations in the Markov limit, predicts gain spectra that do not exhibit absorption below the renormalized band gap, in agreement with experiment. When compared to gain calculations where the in-scattering contribution is neglected, the theory predicts markedly different properties for intrinsic laser parameters, such as peak gain, gain bandwidth, differential gain and carrier density at transparency, especially at low carrier densities.

  15. Active rc filter permits easy trade-off of amplifier gain and sensitivity to gain

    NASA Technical Reports Server (NTRS)

    Kerwin, W. J.; Shaffer, C. V.

    1968-01-01

    Passive RC network was designed with zeros of transmission in the right half of the complex frequency plane in the feedback loop of a simple negative-gain amplifier. The proper positioning provides any desired trade-off between amplifier gain and sensitivity to amplifier gain.

  16. Physical activity and fat mass gain in Mexican school-age children: a cohort study

    PubMed Central

    2012-01-01

    Background In México, the prevalence of unhealthy weight increased from 24% at 6 y to 33% at 12 y of age, opening a window of opportunity to better understand the pathogenesis of obesity. The objective of this study was to explore the association between time spent on medium, vigorous physical activity (MVPA) and concurrent gains in BMI, fat mass (FM) and fat-free mass (FFM), alternately, in a cohort of Mexican children followed from kindergarten (baseline) to 2nd grade elementary school (endline). Methods The MVPA (5-d accelerometry), BMI, FM and FFM (air displacement plethysmography) were measured at baseline and endline. Associations between gains in BMI, FM and FFM and changes in MVPA were examined using lagged and dynamic regression models, controlling for energy intake and demographic variables. Results A total of 205 children were analyzed. Gender affected the effect of MVPA on FM gain. In girls, a high baseline MVPA predicted a lower FM gain (-0.96 kg, p=0.025) compared to low/medium MVPA. Increasing, decreasing or having a persistently high MVPA predicted a lower FM gain (range -1.6 to -1.03 kg, p<0.05) compared to persistently low MVPA. In boys, increases in MVPA were associated with higher gains in BMI (+0.76 kg/m2, p=0.04) and FFM (+1.1 kg, p=0.01) compared to persistently low MVPA. Conclusion These results support a protective role of MVPA on FM gain in girls, suggesting that it may play a crucial role in the development of obesity. Further research on the gender effect of MVPA is warranted to better understand its role in the prevention and control of overweight and obesity. PMID:22839498

  17. Toward the realization of erbium-doped GaN bulk crystals as a gain medium for high energy lasers

    NASA Astrophysics Data System (ADS)

    Sun, Z. Y.; Li, J.; Zhao, W. P.; Lin, J. Y.; Jiang, H. X.

    2016-08-01

    Er-doped GaN (Er:GaN) is a promising candidate as a gain medium for solid-state high energy lasers (HELs) at the technologically important and eye-safe 1.54 μm wavelength window, as GaN has superior thermal properties over traditional laser gain materials such as Nd:YAG. However, the attainment of wafer-scale Er:GaN bulk or quasi-bulk crystals is a prerequisite to realize the full potential of Er:GaN as a gain medium for HELs. We report the realization of freestanding Er:GaN wafers of 2-in. in diameter with a thickness on the millimeter scale. These freestanding wafers were obtained via growth by hydride vapor phase epitaxy in conjunction with a laser-lift-off process. An Er doping level of 1.4 × 1020 atoms/cm3 has been confirmed by secondary ion mass spectrometry measurements. The freestanding Er:GaN wafers exhibit strong photoluminescent emission at 1.54 μm with its emission intensity increasing dramatically with wafer thickness under 980 nm resonant excitation. A low thermal quenching of 10% was measured for the 1.54 μm emission intensity between 10 K and 300 K. This work represents a significant step in providing a practical approach for producing Er:GaN materials with sufficient thicknesses and dimensions to enable the design of gain media in various geometries, allowing for the production of HELs with improved lasing efficiency, atmosphere transmission, and eye-safety.

  18. Raman gain of SiC as a potential medium for Raman lasers

    NASA Astrophysics Data System (ADS)

    Merkle, Larry D.; Zhang, Jun; Allen, Graham; Dawson, Jay W.; Dubinskii, Mark

    2015-03-01

    We have investigated stimulated Raman scattering in the 4H polytype of SiC, due to its excellent thermal conductivity which is of great importance for power scaling of Raman lasers. Spectroscopy verifies the sample's polytype and precludes any significant admixture of other polytypes. Tests indicate the moderate optical quality of this commercially available sample. Using pump-probe measurements around 1030 nm, we find the Raman gain coefficient of the major peak at 777 cm-1 to be 0.46 cm/GW. Although this value is only modest, calculations and experience with other Raman materials indicate that Raman lasing of 4H SiC should be possible with reasonable intensities of 1064-nm pulsed pumping.

  19. High power VCSEL device with periodic gain active region

    NASA Astrophysics Data System (ADS)

    Ning, Y. Q., II; Qin, L.; Sun, Y. F.; Li, T.; Cui, J. J.; Peng, B.; Liu, G. Y.; Zhang, Y.; Liu, Y.; Wang, L. J.; Cui, D. F.; Xu, Z. Y.

    2007-11-01

    High power vertical cavity surface emitting lasers with large aperture have been fabricated through improving passivation, lateral oxidation and heat dissipation techniques. Different from conventional three quantum well structure, a periodic gain active region with nine quantum wells was incorporated into the VCSEL structure, with which high efficiency and high power operation were expected. The nine quantum wells were divided into three groups with each of them located at the antinodes of the cavity to enhance the coupling between the optical field and the gain region. Large aperture and bottom-emitting configuration was used to improve the beam quality and the heat dissipation. A maximum output power of 1.4W was demonstrated at CW operation for a 400μm-diameter device. The lasing wavelength shifted to 995.5nm with a FWHM of 2nm at a current of 4.8A due to the internal heating and the absence of active water cooling. A ring-shape farfield pattern was induced by the non-homogeneous lateral current distribution in large diameter device. The light intensity at the center of the ring increased with increasing current. A symmetric round light spot at the center and single transverse mode operation with a divergence angle of 16° were observed with current beyond 4.8A.

  20. Analytical model of optical field distribution of thin disk laser with thermal-optical aberration gain medium

    NASA Astrophysics Data System (ADS)

    Zhu, Guangzhi; Qiu, Yuli; Wang, Zexiong; Zhu, Xiao; Zhu, Changhong

    2016-08-01

    An analytical model is developed to analyze the optical field distribution of thin disk laser with a thermal-optical aberration gain medium. The fundamental mode field distribution is calculated by using the eigenvector method of the resonator transit matrix for different pumping parameters. The analytical results show that the uniformity of the pumping spot is an important factor that impacts the beam quality of thin disk laser. The uniform pumping spot is beneficial to decrease thermal aberration and Optical Path Difference (OPD) of thin disk crystal, and to improve the beam quality. However, the beam quality still decreases slightly with the increasing of pumping intensity under the uniform pumping condition. The main reason for degradation of beam quality is the aspherical part of OPD which leads to diffraction losses of the resonator and wavefront deformation.

  1. Rigorous theoretical analysis of a surface-plasmon nanolaser with monolayer MoS2 gain medium.

    PubMed

    Meng, Xiang; Grote, Richard R; Jin, Wencan; Dadap, Jerry I; Panoiu, Nicolae C; Osgood, Richard M

    2016-06-01

    Lasers based on monolayer (ML) transition-metal dichalcogenide semiconductor crystals have the potential for low threshold operation and a small device footprint; however, nanophotonic engineering is required to maximize the interaction between the optical fields and the three-atom-thick gain medium. Here, we develop a theoretical model to design a direct bandgap optically pumped nanophotonic integrated laser. Our device utilizes a gap-surface-plasmon optical mode to achieve subwavelength optical confinement and consists of a high-index GaP nanowire atop an ML MoS2 film on an Ag substrate. The optical field and material medium are analyzed using a three dimensional finite-difference time-domain method and a first-principles calculation based on the density functional theory, respectively. The nanolaser is designed to have a threshold of ∼0.6  μW under quasi-continuous wave operation on an excitonic transition at room temperature. PMID:27244433

  2. 20 CFR 220.141 - Substantial gainful activity, defined.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... activities like taking care of one's self, household tasks, hobbies, therapy, school attendance, club...) Substantial work activity. Substantial work activity is work activity that involves doing significant...

  3. 20 CFR 220.141 - Substantial gainful activity, defined.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... activities like taking care of one's self, household tasks, hobbies, therapy, school attendance, club...) Substantial work activity. Substantial work activity is work activity that involves doing significant...

  4. 20 CFR 220.141 - Substantial gainful activity, defined.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... activities like taking care of one's self, household tasks, hobbies, therapy, school attendance, club...) Substantial work activity. Substantial work activity is work activity that involves doing significant...

  5. 20 CFR 220.141 - Substantial gainful activity, defined.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... activities like taking care of one's self, household tasks, hobbies, therapy, school attendance, club...) Substantial work activity. Substantial work activity is work activity that involves doing significant...

  6. 20 CFR 220.141 - Substantial gainful activity, defined.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... activities like taking care of one's self, household tasks, hobbies, therapy, school attendance, club...) Substantial work activity. Substantial work activity is work activity that involves doing significant...

  7. The Calibration of AVHRR/3 Visible Dual Gain Using Meteosat-8 as a MODIS Calibration Transfer Medium

    NASA Technical Reports Server (NTRS)

    Avey, Lance; Garber, Donald; Nguyen, Louis; Minnis, Patrick

    2007-01-01

    This viewgraph presentation reviews the NOAA-17 AVHRR visible channels calibrated against MET-8/MODIS using dual gain regression methods. The topics include: 1) Motivation; 2) Methodology; 3) Dual Gain Regression Methods; 4) Examples of Regression methods; 5) AVHRR/3 Regression Strategy; 6) Cross-Calibration Method; 7) Spectral Response Functions; 8) MET8/NOAA-17; 9) Example of gain ratio adjustment; 10) Effect of mixed low/high count FOV; 11) Monitor dual gains over time; and 12) Conclusions

  8. Amplification of ultrashort pulses to 0.5 TW at 5 Hz with a flashlamp pumped Cr:LiSAF gain medium

    NASA Astrophysics Data System (ADS)

    Samad, Ricardo E.; Nogueira, Gesse E. C.; Baldochi, Sonia L.; Vieira, Nilson D., Jr.

    2007-02-01

    We report here the development and construction of a two-flashlamp pumping cavity for a Cr:LiSAF rod, to be operated as a multipass amplifier in a Chirped Pulse Amplifier system. The pumping cavity was designed to minimize the thermal load on the gain medium by the utilization of intracavity filters, aiming operation with high gain and the highest possible repetition rate. Operating as a laser, 30 Hz repetition rate and 20 W average power were obtained for the first time at a maximum gain per pass of 1.5. Changing the pumping characteristics, the laser provided 16 W at 8 Hz repetition rate, at a maximum gain of 3.6. A four-pass multipass amplifier geometry was designed for the pumping cavity, that was integrated and synchronized to a Ti:Sapphire Chirped Pulse Amplifier system. The amplification properties of the gain medium were determined, in one, two and four passes, along with the gain dependence on the repetition rate. The amplifier final configuration provided amplification by a factor 150 to 20 ps stretched pulses, resulting in final compressed pulses with 60 fs and 0.5 TW of peak power at 5 Hz repetition rate.

  9. 20 CFR 220.29 - Work that is considered substantial gainful activity.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Employment § 220.29 Work that is considered substantial gainful activity. Work is considered to be substantial gainful activity if it— (a) Involves doing significant and productive physical or mental duties... activity. 220.29 Section 220.29 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER...

  10. 20 CFR 220.29 - Work that is considered substantial gainful activity.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Employment § 220.29 Work that is considered substantial gainful activity. Work is considered to be substantial gainful activity if it— (a) Involves doing significant and productive physical or mental duties... activity. 220.29 Section 220.29 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER...

  11. 20 CFR 220.29 - Work that is considered substantial gainful activity.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Employment § 220.29 Work that is considered substantial gainful activity. Work is considered to be substantial gainful activity if it— (a) Involves doing significant and productive physical or mental duties... activity. 220.29 Section 220.29 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER...

  12. Plasma-activated medium induced apoptosis on tumor cells

    NASA Astrophysics Data System (ADS)

    Hori, Masaru; Tanaka, Hiromasa; Mizuno, Masaaki; Nakamura, Kae; Kajiyama, Hiroaki; Takeda, Keigo; Ishikawa, Kenji; Kano, Hiroyuki; Kikkawa, Fumitaka

    2013-09-01

    The non-equilibrium atmospheric pressure plasma (NEAPP) has attracted attention in cancer therapy. In this study, the fresh medium was treated with our developed NEAPP, ultra-high electron density (approximately 2 × 1016 cm-3). The medium called the plasma-activated medium (PAM) killed not normal cells but tumor cells through induction of apoptosis. Cell proliferation assays showed that the tumor cells were selectively killed by the PAM. Those cells induced apoptosis using an apoptotic molecular marker, cleaved Caspase3/7. The molecular mechanisms of PAM-mediated apoptosis in the tumor cells were also found that the PAM downregulated the expression of AKT kinase, a marker molecule in a survival signal transduction pathway. These results suggest that PAM may be a promising tool for tumor therapy by downregulating the survival signals in cancers.

  13. Exploring Sudden Gains in Behavioral Activation Therapy for Major Depressive Disorder

    PubMed Central

    Hunnicutt-Ferguson, Kallio; Hoxha, Denada; Gollan, Jackie

    2012-01-01

    Understanding the onset and course of sudden gains in treatment provides clinical information to the patient and clinician, and encourages clinicians to strive for these sudden clinical gains with their patients. This study characterizes the occurrence of sudden gains with Behavioral Activation (BA; Martell, Addis, & Jacobson, 2001), and the extent to which pre-treatment dysfunctional depressive thinking predicts sudden gains during treatment. We enrolled a sample of adults (n = 42) between ages 18–65 diagnosed with primary Major Depressive Disorder. All participants completed a 16-week course of BA, with clinical and self-report assessments at pre-, mid- and post-treatment. Results indicated that sudden gain and non-sudden gain participants showed differential improvement across treatment. No significant effects emerged for the dysfunctional cognitive style as a predictor of sudden gain status. Sudden gains may result from interaction of non-specific factors with the BA techniques implemented during early phases of therapy. PMID:22336434

  14. 26 CFR 7.105-2 - Substantial gainful activity.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., institutional therapy or training, school attendance, clubs, social programs, and similar activities is not... from employment as a teacher because of terminal cancer. The taxpayer's physician...

  15. 20 CFR 229.85 - Substantial gainful activity by blind employee or child.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false Substantial gainful activity by blind... Reductions § 229.85 Substantial gainful activity by blind employee or child. A blind employee or child who is 55 years old or older is entitled to an O/M benefit based on disability while he or she is working...

  16. 20 CFR 229.85 - Substantial gainful activity by blind employee or child.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 1 2014-04-01 2012-04-01 true Substantial gainful activity by blind employee... § 229.85 Substantial gainful activity by blind employee or child. A blind employee or child who is 55 years old or older is entitled to an O/M benefit based on disability while he or she is working...

  17. 20 CFR 229.85 - Substantial gainful activity by blind employee or child.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Substantial gainful activity by blind... Reductions § 229.85 Substantial gainful activity by blind employee or child. A blind employee or child who is 55 years old or older is entitled to an O/M benefit based on disability while he or she is working...

  18. 20 CFR 229.85 - Substantial gainful activity by blind employee or child.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Substantial gainful activity by blind employee... § 229.85 Substantial gainful activity by blind employee or child. A blind employee or child who is 55 years old or older is entitled to an O/M benefit based on disability while he or she is working...

  19. 20 CFR 229.85 - Substantial gainful activity by blind employee or child.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Substantial gainful activity by blind... Reductions § 229.85 Substantial gainful activity by blind employee or child. A blind employee or child who is 55 years old or older is entitled to an O/M benefit based on disability while he or she is working...

  20. Envelope evolution of a laser pulse in an active medium

    SciTech Connect

    Fisher, D.L.; Tajima, T.; Downer, M.C.; Siders, C.W.

    1994-11-01

    The authors show that the envelope velocity, v{sub env}, of a short laser pulse can, via propagation in an active medium, be made less than, equal to, or even greater than c, the vacuum phase velocity of light. Simulation results, based on moving frame propagation equations coupling the laser pulse, active medium and plasma, are presented, as well as equations that determines the design value of super- and sub-luminous v{sub env}. In this simulation the laser pulse evolves in time in a moving frame as opposed to their earlier work where the profile was fixed. The elimination of phase slippage and pump depletion effects in the laser wakefield accelerator is discussed as a particular application. Finally they discuss media properties necessary for an experimental realization of this technique.

  1. Measurement of the gain in a disk amplification stage with neodymium phosphate glass active elements

    SciTech Connect

    Voronich, Ivan N; Galakhov, I V; Garanin, Sergey G; Eroshenko, V A; Zaretskii, Aleksei I; Zimalin, B G; Ignat'ev, Ivan V; Kirdyashkin, M Yu; Kirillov, G A; Osin, Vladimir A; Rukavishnikov, N N; Sukharev, Stanislav A; Sharov, Oleg A; Charukhchev, Aleksandr V

    2003-06-30

    The measuring technique is described and time-resolved measurements of the small-signal gain as a function of the pump energy in a disk amplification stage with neodymium phosphate glass active elements in the 'Luch' facility are presented. The distribution of the gain over the amplifier aperture in the horizontal plane is measured. (lasers)

  2. Responses of cells in plasma-activated medium

    NASA Astrophysics Data System (ADS)

    Tanaka, Hiromasa; Mizuno, Masaaki; Ishikawa, Kenji; Takeda, Keigo; Hashizume, Hiroshi; Nakamura, Kae; Kajiyama, Hiroaki; Kano, Hiroyuki; Okazaki, Yasumasa; Toyokuni, Shinya; Maruyama, Shoichi; Kodera, Yasuhiro; Terasaki, Hiroko; Adachi, Tetsuo; Kato, Masashi; Kikkawa, Fumitaka; Hori, Masaru

    2015-09-01

    Plasma consists of electrons, ions, radicals, and lights, and produces various reactive species in gas and liquid phase. Cells receive various inputs from their circumstances, and induce several physiological outputs. Our goal is to clarify the relationships between plasma inputs and physiological outputs. Plasma-activated medium (PAM) is a circumstance that plasma provides cells and our previous studies suggest that PAM is a promising tool for cancer therapy. However, the mode of actions remains to be elucidated. We propose survival and proliferation signaling networks as well as redox signaling networks are key factors to understand cellular responses of PAM-treated glioblastoma cells.

  3. Neighborhood factors associated with physical activity and adequacy of weight gain during pregnancy

    EPA Science Inventory

    Healthy diet, physical activity, smoking, and adequate weight gain are all associated with maternal health and fetal growth during pregnancy. Neighborhood characteristics have been associated with poor maternal and child health outcomes, yet conceptualization of potential mechani...

  4. Transient medium-scale wave activity in the summer stratosphere

    NASA Technical Reports Server (NTRS)

    Miles, T.; Grose, W. L.

    1986-01-01

    Observations of medium-scale transient wave activity in the middle-latitude Southern Hemisphere summer stratosphere are interpreted using isentropic potential vorticity (IPV) distributions inferred from temperature data from the Nimbus-7 Limb Infrared Monitor of the Stratosphere (LIMS) instrument. Despite problems with errors in reference-level synoptic height information, the derived IPV distributions clearly exhibit dynamically coherent signatures of eddy mixing due to medium-scale disturbances in the lower-middle stratosphere during early January 1979. The IPV distributions are shown to be strongly correlated with those of a contemporaneous set of isentropic maps of quasi-conservative tracers such as ozone and nitric acid. The results suggest that IPV maps inferred from satellite temperature data provide a useful diagnostic for studies of large-scale dynamics and/or transport in the extratropical stratosphere. Furthermore, the comparatively high vertical resolution of the LIMS data has enabled the vertical attenuation of Southern Hemisphere wave activity to be diagnosed in greater detail than could be achieved from nadir-viewing satellite information.

  5. Phase Segregation of Passive Advective Particles in an Active Medium.

    PubMed

    Das, Amit; Polley, Anirban; Rao, Madan

    2016-02-12

    Localized contractile configurations or asters spontaneously appear and disappear as emergent structures in the collective stochastic dynamics of active polar actomyosin filaments. Passive particles which (un)bind to the active filaments get advected into the asters, forming transient clusters. We study the phase segregation of such passive advective scalars in a medium of dynamic asters, as a function of the aster density and the ratio of the rates of aster remodeling to particle diffusion. The dynamics of coarsening shows a violation of Porod behavior; the growing domains have diffuse interfaces and low interfacial tension. The phase-segregated steady state shows strong macroscopic fluctuations characterized by multiscaling and intermittency, signifying rapid reorganization of macroscopic structures. We expect these unique nonequilibrium features to manifest in the actin-dependent molecular clustering at the cell surface. PMID:26919022

  6. Phase Segregation of Passive Advective Particles in an Active Medium

    NASA Astrophysics Data System (ADS)

    Das, Amit; Polley, Anirban; Rao, Madan

    2016-02-01

    Localized contractile configurations or asters spontaneously appear and disappear as emergent structures in the collective stochastic dynamics of active polar actomyosin filaments. Passive particles which (un)bind to the active filaments get advected into the asters, forming transient clusters. We study the phase segregation of such passive advective scalars in a medium of dynamic asters, as a function of the aster density and the ratio of the rates of aster remodeling to particle diffusion. The dynamics of coarsening shows a violation of Porod behavior; the growing domains have diffuse interfaces and low interfacial tension. The phase-segregated steady state shows strong macroscopic fluctuations characterized by multiscaling and intermittency, signifying rapid reorganization of macroscopic structures. We expect these unique nonequilibrium features to manifest in the actin-dependent molecular clustering at the cell surface.

  7. Maintaining a High Physical Activity Level Over 20 Years and Weight Gain

    PubMed Central

    Hankinson, Arlene L.; Daviglus, Martha L.; Bouchard, Claude; Carnethon, Mercedes; Lewis, Cora E.; Schreiner, Pamela J.; Liu, Kiang; Sidney, Stephen

    2013-01-01

    Context Data supporting physical activity guidelines to prevent long-term weight gain are sparse, particularly during the period when the highest risk of weight gain occurs. Objective To evaluate the relationship between habitual activity levels and changes in body mass index (BMI) and waist circumference over 20 years. Design, Setting, and Participants The Coronary Artery Risk Development in Young Adults (CARDIA) study is a prospective longitudinal study with 20 years of follow-up, 1985-86 to 2005-06. Habitual activity was defined as maintaining high, moderate, and low activity levels based on sex-specific tertiles of activity scores at baseline. Participants comprised a population-based multi-center cohort (Chicago, Illinois; Birmingham, Alabama; Minneapolis, Minnesota; and Oakland, California) of 3554 men and women aged 18 to 30 years at baseline. Main Outcome Measures Average annual changes in BMI and waist circumference Results Over 20 years, maintaining high levels of activity was associated with smaller gains in BMI and waist circumference compared with low activity levels after adjustment for race, baseline BMI, age, education, cigarette smoking status, alcohol use, and energy intake. Men maintaining high activity gained 2.6 fewer kilograms (+ 0.15 BMI units per year; 95 % confidence interval [CI] 0.11-0.18 vs +0.20 in the lower activity group; 95% CI, 0.17-0.23) and women maintaining higher activity gained 6.1 fewer kilograms (+0.17 BMI units per year; 95 % CI, 0.12-0.21 vs. +0.30 in the lower activity group; 95 % CI, 0.25-0.34). Men maintaining high activity gained 3.1 fewer centimeters in waist circumference (+0.52 cm per year; 95 % CI, 0.43-0.61 cm vs 0.67 cm in the lower activity group; 95 % CI, 0.60-0.75) and women maintaining higher activity gained 3.8 fewer centimeters (+0.49 cm per year; 95 % CI, 0.39-0.58 vs 0.67 cm in the lower activity group; 95 % CI, 0.60-0.75). Conclusion Maintaining high activity levels through young adulthood may lessen

  8. Contact heat conductance at a diamond-OFHC copper interface with GaIn eutectic as a heat transfer medium

    NASA Astrophysics Data System (ADS)

    Assoufid, L.; Khounsary, A. M.

    1996-09-01

    The results of an experimental study of the contact heat conductance across a single diamond crystal interface with OFHC copper (Cu) are reported. Gallium-indium (GaIn) eutectic was used as an interstitial material. Contact conductance data are important in the design and the prediction of the performance of x-ray optics under high-heat-load conditions. Two sets of experiments were carried out. In one, the copper surface in contact with diamond was polished and then electroless plated with 1 μm of nickel, while in the other, the copper contact surface was left as machined. The measured average interface heat conductances are 44.7±8 W/cm2-K for nonplated copper and 23.0±8 W/cm2-K for nickel-plated copper. For reference, the thermal contact conductances at a copper-copper interface (without diamond) were also measured, and the results are reported. A typical diamond monochromator, 0.2 mm thick, will absorb about 44 W under a standard undulator beam at the Advanced Photon Source. The measured conductance for nickel-plated copper suggests that the temperature drop across the interface of diamond and nickel-plated copper, with a 20 mm 2 contact area, will be about 10°C. Therefore temperature rises are rather modest, and the accuracy of the measured contact conductances presented here are sufficient for design purposes.

  9. Contact heat conductance at a diamond-OFHC copper interface with GaIn eutectic as a heat transfer medium

    SciTech Connect

    Assoufid, L.; Khounsary, A.

    1996-09-01

    The results of an experimental study of the contact heat conductance across a single diamond crystal interface with OFHC copper (Cu) are reported. Gallium-indium (GaIn) eutectic was used as an interstitial material. Contact conductance data are important in the design and the prediction of the performance of x-ray optics under high-heat-load conditions. Two sets of experiments were carried out. In one, the copper surface in contact with diamond was polished and then electroless plated with 1 {mu}m of nickel, while in the other, the copper contact surface was left as machined. The measured average interface heat conductances are 44.7{plus_minus}8 W/cm{sup 2}-K for nonplated copper and 23.0{plus_minus}8 W/cm{sup 2}-K for nickel-plated copper. For reference, the thermal contact conductances at a copper-copper interface (without diamond) were also measured, and the results are reported. A typical diamond monochromator, 0.2 mm thick, will absorb about 44 W under a standard undulator beam at the Advanced Photon Source. The measured conductance for nickel-plated copper suggests that the temperature drop across the interface of diamond and nickel-plated copper, with a 20 mm {sup 2}contact area, will be about 10{degree}C. Therefore temperature rises are rather modest, and the accuracy of the measured contact conductances presented here are sufficient for design purposes. {copyright} {ital 1996 American Institute of Physics.}

  10. Role of nonexercise activity thermogenesis in resistance to fat gain in humans.

    PubMed

    Levine, J A; Eberhardt, N L; Jensen, M D

    1999-01-01

    Humans show considerable interindividual variation in susceptibility to weight gain in response to overeating. The physiological basis of this variation was investigated by measuring changes in energy storage and expenditure in 16 nonobese volunteers who were fed 1000 kilocalories per day in excess of weight-maintenance requirements for 8 weeks. Two-thirds of the increases in total daily energy expenditure was due to increased nonexercise activity thermogenesis (NEAT), which is associated with fidgeting, maintenance of posture, and other physical activities of daily life. Changes in NEAT accounted for the 10-fold differences in fat storage that occurred and directly predicted resistance to fat gain with overfeeding (correlation coefficient = 0.77, probability < 0.001). These results suggest that as humans overeat, activation of NEAT dissipates excess energy to preserve leanness and that failure to activate NEAT may result in ready fat gain. PMID:9880251

  11. Women and Training for Rural Gainful Activities (TRUGA). Training Discussion Paper No. 72.

    ERIC Educational Resources Information Center

    Baidya, Bhuchandra P. R.; Chaudhari, Gayatri

    An evaluative study was conducted of the Training for Rural Gainful Activities (TRUGA) project and methodology in Nepal regarding women's participation and benefits. The study analyzed TRUGA as a project and as a training methodology, assessed the effects of TRUGA activities on women, and evaluated project investment in and benefits to women.…

  12. Cell survival of glioblastoma grown in medium containing hydrogen peroxide and/or nitrite, or in plasma-activated medium.

    PubMed

    Kurake, Naoyuki; Tanaka, Hiromasa; Ishikawa, Kenji; Kondo, Takashi; Sekine, Makoto; Nakamura, Kae; Kajiyama, Hiroaki; Kikkawa, Fumitaka; Mizuno, Masaaki; Hori, Masaru

    2016-09-01

    Non-equilibrium atmospheric pressure plasmas generate a high electron density (on the order of 10(16) electrons per cm(-3)) using Ar gas. Culture medium in air at room temperature was plasma-irradiated for several hundred seconds. Tens of micromolar hydrogen peroxide (H2O2) and millimolar levels of nitrous ion (NO2(-)) were detected in the plasma-irradiated culture medium (plasma activated medium; PAM) and selectively induced the apoptotic death of glioblastoma tumor cells, but did not kill normal mammary epithelial cells. A similar antitumor effect was induced by spiking the medium with comparable concentrations of H2O2 and NO2(-). The PAM remained still a somewhat difference that it should also be assessed for understanding other latent mechanisms. PMID:26820218

  13. Goos-Hänchen shifts of partially coherent light beams from a cavity with a four-level Raman gain medium

    NASA Astrophysics Data System (ADS)

    Ziauddin; Lee, Ray-Kuang; Qamar, Sajid

    2016-09-01

    We theoretically investigate spatial and angular Goos-Hänchen (GH) shifts (both negative and positive) in the reflected light for a partial coherent light incident on a cavity. A four-level Raman gain atomic medium is considered in a cavity. The effects of spatial coherence, beam width, and mode index of partial coherent light fields on spatial and angular GH shifts are studied. Our results reveal that a large magnitude of negative and positive GH shifts in the reflected light is achievable with the introduction of partial coherent light fields. Furthermore, the amplitude of spatial (negative and positive) GH shifts are sharply affected by the partial coherent light beam as compared to angular (negative and positive) GH shifts in the reflected light.

  14. Spontaneous regional brain activity links restrained eating to later weight gain among young women.

    PubMed

    Dong, Debo; Jackson, Todd; Wang, Yulin; Chen, Hong

    2015-07-01

    Theory and prospective studies have linked restrained eating (RE) to risk for future weight gain and the onset of obesity, but little is known about resting state neural activity that may underlie this association. To address this gap, resting fMRI was used to test the extent to which spontaneous neural activity in regions associated with inhibitory control and food reward account for potential relations between baseline RE levels and changes in body weight among dieters over a one-year interval. Spontaneous regional activity patterns corresponding to RE were assessed among 50 young women using regional homogeneity (ReHo) analysis, which measured temporal synchronization of spontaneous fluctuations within a food deprivation condition. Analyses indicated higher baseline RE scores predicted more weight gain at a one-year follow-up. Furthermore, food-deprived dieting women with high dietary restraint scores exhibited more spontaneous local activity in brain regions associated with the expectation and valuation for food reward [i.e., orbitofrontal cortex (OFC)/ventromedial prefrontal cortex (VMPFC)] and reduced spontaneous local activity in inhibitory control regions [i.e., bilateral dorsal-lateral prefrontal cortex (DLPFC)] at baseline. Notably, the association between baseline RE and follow-up weight gain was mediated by decreased local synchronization of the right DLPFC in particular and, to a lesser degree, increased local synchronization of the right VMPFC. In conjunction with previous research, these findings highlight possible neural mechanisms underlying the relation between RE and risk for weight gain. PMID:26004091

  15. External locus of control contributes to racial disparities in memory and reasoning training gains in ACTIVE.

    PubMed

    Zahodne, Laura B; Meyer, Oanh L; Choi, Eunhee; Thomas, Michael L; Willis, Sherry L; Marsiske, Michael; Gross, Alden L; Rebok, George W; Parisi, Jeanine M

    2015-09-01

    Racial disparities in cognitive outcomes may be partly explained by differences in locus of control. African Americans report more external locus of control than non-Hispanic Whites, and external locus of control is associated with poorer health and cognition. The aims of this study were to compare cognitive training gains between African American and non-Hispanic White participants in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study and determine whether racial differences in training gains are mediated by locus of control. The sample comprised 2,062 (26% African American) adults aged 65 and older who participated in memory, reasoning, or speed training. Latent growth curve models evaluated predictors of 10-year cognitive trajectories separately by training group. Multiple group modeling examined associations between training gains and locus of control across racial groups. Compared to non-Hispanic Whites, African Americans evidenced less improvement in memory and reasoning performance after training. These effects were partially mediated by locus of control, controlling for age, sex, education, health, depression, testing site, and initial cognitive ability. African Americans reported more external locus of control, which was associated with smaller training gains. External locus of control also had a stronger negative association with reasoning training gain for African Americans than for Whites. No racial difference in training gain was identified for speed training. Future intervention research with African Americans should test whether explicitly targeting external locus of control leads to greater cognitive improvement following cognitive training. PMID:26237116

  16. External locus of control contributes to racial disparities in memory and reasoning training gains in ACTIVE

    PubMed Central

    Zahodne, Laura B.; Meyer, Oanh L.; Choi, Eunhee; Thomas, Michael L.; Willis, Sherry L.; Marsiske, Michael; Gross, Alden L.; Rebok, George W.; Parisi, Jeanine M.

    2015-01-01

    Racial disparities in cognitive outcomes may be partly explained by differences in locus of control. African Americans report more external locus of control than non-Hispanic Whites, and external locus of control is associated with poorer health and cognition. The aims of this study were to compare cognitive training gains between African American and non-Hispanic White participants in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study and determine whether racial differences in training gains are mediated by locus of control. The sample comprised 2,062 (26% African American) adults aged 65 and older who participated in memory, reasoning, or speed training. Latent growth curve models evaluated predictors of 10-year cognitive trajectories separately by training group. Multiple group modeling examined associations between training gains and locus of control across racial groups. Compared to non-Hispanic Whites, African Americans evidenced less improvement in memory and reasoning performance after training. These effects were partially mediated by locus of control, controlling for age, sex, education, health, depression, testing site, and initial cognitive ability. African Americans reported more external locus of control, which was associated with smaller training gains. External locus of control also had a stronger negative association with reasoning training gain for African Americans than for Whites. No racial difference in training gain was identified for speed training. Future intervention research with African Americans should test whether explicitly targeting external locus of control leads to greater cognitive improvement following cognitive training. PMID:26237116

  17. ACTIVE MEDIA: Dynamics of growth of inhomogeneities in the active medium of a liquid laser

    NASA Astrophysics Data System (ADS)

    Barikhin, B. A.; Ivanov, A. Yu; Kudryavkin, E. V.; Nedolugov, V. I.

    1991-07-01

    Fast cinematography of holograms and of shadow and interference patterns was combined with an acoustic method in a study of the dynamics of growth of inhomogeneities in the active medium of a coaxially pumped dye laser. The main mechanism of the formation of these inhomogeneities was related to acoustic waves created by the deformation of the walls of a dye cell created by electrical pulses applied to the pump flashlamp. Multipulse operation of this laser could be achieved and the off-duty factor could be reduced if the active medium was excited by the strongest possible pump pulses.

  18. Two-phase flow in a chemically active porous medium

    SciTech Connect

    Darmon, Alexandre Dauchot, Olivier; Benzaquen, Michael; Salez, Thomas

    2014-12-28

    We study the problem of the transformation of a given reactant species into an immiscible product species, as they flow through a chemically active porous medium. We derive the equation governing the evolution of the volume fraction of the species, in a one-dimensional macroscopic description, identify the relevant dimensionless numbers, and provide simple models for capillary pressure and relative permeabilities, which are quantities of crucial importance when tackling multiphase flows in porous media. We set the domain of validity of our models and discuss the importance of viscous coupling terms in the extended Darcy’s law. We investigate numerically the steady regime and demonstrate that the spatial transformation rate of the species along the reactor is non-monotonous, as testified by the existence of an inflection point in the volume fraction profiles. We obtain the scaling of the location of this inflection point with the dimensionless lengths of the problem. Eventually, we provide key elements for optimization of the reactor.

  19. Optimisation of gain matrix with UZAWA algorithm—theory and application to an active panel

    NASA Astrophysics Data System (ADS)

    Arrouf, Mhamed; Charon, Willy; Peyraut, François

    2004-03-01

    This paper deals with the gain matrix optimisation in the framework of adaptive mechanical systems with LQG control. The purpose of this optimisation is to provide to the engineer the theoretical tools enabling him to position actuators as well as possible on a structure. It was carried out using a conventional UZAWA algorithm which was adapted to the active system context.

  20. 20 CFR 404.1572 - What we mean by substantial gainful activity.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false What we mean by substantial gainful activity. 404.1572 Section 404.1572 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Substantial...

  1. 20 CFR 404.1572 - What we mean by substantial gainful activity.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false What we mean by substantial gainful activity. 404.1572 Section 404.1572 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Substantial...

  2. 20 CFR 404.1572 - What we mean by substantial gainful activity.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false What we mean by substantial gainful activity. 404.1572 Section 404.1572 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Substantial...

  3. 20 CFR 404.1572 - What we mean by substantial gainful activity.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false What we mean by substantial gainful activity. 404.1572 Section 404.1572 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Substantial...

  4. 20 CFR 404.1572 - What we mean by substantial gainful activity.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false What we mean by substantial gainful activity. 404.1572 Section 404.1572 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Substantial...

  5. Dietary Fructose and GLUT5 Transporter Activity Contribute to Antipsychotic-Induced Weight Gain.

    PubMed

    Palavicino-Maggio, Caroline B; Kuzhikandathil, Eldo V

    2016-09-01

    Receptors for antipsychotics in the hypothalamus contribute to antipsychotics-induced weight gain; however, many of these receptors are also expressed in the intestine. The role of these intestinally-expressed receptors, and their potential modulation of nutrient absorption, have not been investigated in the context of antipsychotics-induced weight gain. Here we tested the effect of dietary fructose and intestinal fructose uptake on clozapine-induced weight gain in mice. Weight gain was determined in wild type mice and mice lacking the GLUT5 fructose transporter that were "orally-administered" 20mg/kg clozapine for 28 days. To assess the role of dietary fructose, clozapine-treated mice were fed controlled diets with different levels of fructose. Effect of clozapine treatment on intestinal fructose transport activity and expression levels of various receptors that bind clozapine, as well as several genes involved in gluconeogenesis and lipogenesis were measured using real-time RT-PCR and western blotting. Oral administration of clozapine significantly increased body weight in wild type C57BL/6 mice but not in GLUT5 null mice. The clozapine-induced weight gain was proportional to the percentage of fructose in the diet. Clozapine-treated mice increased intestinal fructose uptake without changing the intestinal expression level of GLUT5. Clozapine-treated mice expressed significantly higher levels of intestinal H1 histamine receptor in the wild type but not GLUT5 null mice. Clozapine also increased the intestinal expression of fructokinase and several genes involved in gluconeogenesis and lipogenesis. Our results suggest that increased intestinal absorption and metabolism of fructose contributes to clozapine-induced weight gain. Eliminating dietary fructose might prevent antipsychotics-induced weight gain. PMID:27056716

  6. Effects of weight gain induced by controlled overfeeding on physical activity

    PubMed Central

    Bray, George A.; Smith, Steven R.; de Jonge, Lilian; Rood, Jennifer; Han, Hongmei; Redman, Leanne M.; Martin, Corby K.

    2014-01-01

    It is unclear whether physical activity changes following long-term overfeeding and in response to different dietary protein intakes. Twenty-five (16 males, 9 females) healthy adults (18–35 yr) with BMI ranging from 19 to 30 kg/m2 enrolled in this inpatient study. In a parallel group design, participants were fed 140% of energy needs, with 5, 15, or 25% of energy from protein, for 56 days. Participants wore an RT3 accelerometer for at least 59 days throughout baseline and during overfeeding and completed 24-h whole room metabolic chamber assessments at baseline and on days 1, 14, and 56 of overfeeding and on day 57, when the baseline energy intake was consumed, to measure percent of time active and spontaneous physical activity (SPA; kcal/day). Changes in activity were also assessed by doubly labeled water (DLW). From accelerometry, vector magnitude (VM), a weight-independent measure of activity, and activity energy expenditure (AEE) increased with weight gain during overfeeding. AEE remained increased after adjusting for changes in body composition. Activity-related energy expenditure (AREE) from DLW and percent activity and SPA in the metabolic chamber increased with overfeeding, but SPA was no longer significant after adjusting for change in body composition. Change in VM and AEE were positively correlated with weight gain; however, change in activity was not affected by protein intake. Overfeeding produces an increase in physical activity and in energy expended in physical activity after adjusting for changes in body composition, suggesting that increased activity in response to weight gain might be one mechanism to support adaptive thermogenesis. PMID:25294214

  7. [Determination of the biological activity of aminoglycoside antibiotics on a dry nutrient medium of Soviet manufacture].

    PubMed

    Grigor'eva, V M; Andreeva, Z M; Astanina, L N; Shiriaeva, V L; Gridneva, N I

    1981-06-01

    Possible use of the dry nutrient medium manufactured in the USSR for the assay of aminoglycoside antibiotic activity with the agar diffusion method was studied. The optimal conditions for the antibiotic activity assay on this medium were developed. The dry nutrient medium may be used for the activity assay of the aminoglycoside antibiotics, i. e. streptomycin sulfate, dihydrostreptomycin sulfate, neomycin sulfate, monomycin and gentamicin sulfate. PMID:7271256

  8. Gain-Of-Function Mutational Activation of Human TRNA Synthetase Procytokine

    SciTech Connect

    Yang, X.L.; Kapoor, M.; Otero, F.J.; Slike, B.M.; Tsuruta, H.; Frausto, R.; Bates, A.; Ewalt, K.L.; Cheresh, D.A.; Schimmel, P.; /Scripps Res. Inst. /SLAC, SSRL

    2009-04-30

    Disease-causing mutations occur in genes for aminoacyl tRNA synthetases. That some mutations are dominant suggests a gain of function. Native tRNA synthetases, such as tyrosyl-tRNA synthetase (TyrRS) and tryptophanyl-tRNA synthetase, catalyze aminoacylation and are also procytokines that are activated by natural fragmentation. In principle, however, gain-of-function phenotypes could arise from mutational activation of synthetase procytokines. From crystal structure analysis, we hypothesized that a steric block of a critical Glu-Leu-Arg (ELR) motif in full-length TyrRS suppresses the cytokine activity of a natural fragment. To test this hypothesis, we attempted to uncover ELR in the procytokine by mutating a conserved tyrosine (Y341) that tethers ELR. Site-specific proteolytic cleavage and small-angle X-ray scattering established subtle opening of the structure by the mutation. Strikingly, four different assays demonstrated mutational activation of cytokine functions. The results prove the possibilities for constitutive gain-of-function mutations in tRNA synthetases.

  9. Gain-of-Function Mutational Activation of Human tRNA Synthetase Procytokine

    PubMed Central

    Yang, Xiang-Lei; Kapoor, Mili; Otero, Francella J.; Slike, Bonnie M.; Tsuruta, Hiro; Frausto, Ricardo; Bates, Alison; Ewalt, Karla L.; Cheresh, David A.; Schimmel, Paul

    2008-01-01

    Summary Disease-causing mutations occur in genes for aminoacyl tRNA synthetases. That some mutations are dominant suggests a gain-of-function. Native tRNA synthetases, like TyrRS and TrpRS, catalyze aminoacylation and are also procytokines that are activated by natural fragmentation. In principle, however, gain-of-function phenotypes could arise from mutational activation of synthetase procytokines. From crystal structure analysis we hypothesized that a steric block of a critical ELR motif in full-length TyrRS suppresses the cytokine activity of a natural fragment. To test this hypothesis, we attempted to uncover ELR in the procytokine by mutating a conserved tyrosine (Y341) that tethers ELR. Site-specific proteolytic cleavage and small angle X-ray scattering established subtle opening of the structure by the mutation. Strikingly, four different assays demonstrated mutational activation of cytokine functions. The results prove the possibilities for constitutive gain-of-function mutations in tRNA synthetases. PMID:18096501

  10. Gain-of-function mutational activation of human tRNA synthetase procytokine.

    PubMed

    Yang, Xiang-Lei; Kapoor, Mili; Otero, Francella J; Slike, Bonnie M; Tsuruta, Hiro; Frausto, Ricardo; Bates, Alison; Ewalt, Karla L; Cheresh, David A; Schimmel, Paul

    2007-12-01

    Disease-causing mutations occur in genes for aminoacyl tRNA synthetases. That some mutations are dominant suggests a gain of function. Native tRNA synthetases, such as tyrosyl-tRNA synthetase (TyrRS) and tryptophanyl-tRNA synthetase, catalyze aminoacylation and are also procytokines that are activated by natural fragmentation. In principle, however, gain-of-function phenotypes could arise from mutational activation of synthetase procytokines. From crystal structure analysis, we hypothesized that a steric block of a critical Glu-Leu-Arg (ELR) motif in full-length TyrRS suppresses the cytokine activity of a natural fragment. To test this hypothesis, we attempted to uncover ELR in the procytokine by mutating a conserved tyrosine (Y341) that tethers ELR. Site-specific proteolytic cleavage and small-angle X-ray scattering established subtle opening of the structure by the mutation. Strikingly, four different assays demonstrated mutational activation of cytokine functions. The results prove the possibilities for constitutive gain-of-function mutations in tRNA synthetases. PMID:18096501

  11. Representation of potential information gain to measure the price of anarchy on ISR activities

    NASA Astrophysics Data System (ADS)

    Ortiz-Peña, Hector J.; Hirsch, Michael; Karwan, Mark; Nagi, Rakesh; Sudit, Moises

    2013-05-01

    One of the main technical challenges facing intelligence analysts today is effectively determining information gaps from huge amounts of collected data. Moreover, getting the right information to/from the right person (e.g., analyst, warfighter on the edge) at the right time in a distributed environment has been elusive to our military forces. Synchronization of Intelligence, Surveillance, and Reconnaissance (ISR) activities to maximize the efficient utilization of limited resources (both in quantity and capabilities) has become critically important to increase the accuracy and timeliness of overall information gain. Given this reality, we are interested in quantifying the degradation of solution quality (i.e., information gain) as a centralized system synchronizing ISR activities (from information gap identification to information collection and dissemination) moves to a more decentralized framework. This evaluation extends the concept of price of anarchy, a measure of the inefficiency of a system when agents maximize decisions without coordination, by considering different levels of decentralization. Our initial research representing the potential information gain in geospatial and time discretized spaces is presented. This potential information gain map can represent a consolidation of Intelligence Preparation of the Battlefield products as input to automated ISR synchronization tools. Using the coordination of unmanned vehicles (UxVs) as an example, we developed a mathematical programming model for multi-perspective optimization in which each UxV develops its own fight plan to support mission objectives based only on its perspective of the environment (i.e., potential information gain map). Information is only exchanged when UxVs are part of the same communication network.

  12. Pregnant women's perceptions of weight gain, physical activity, and nutrition using Theory of Planned Behavior constructs.

    PubMed

    Whitaker, Kara M; Wilcox, Sara; Liu, Jihong; Blair, Steven N; Pate, Russell R

    2016-02-01

    A better understanding of women's perceptions of weight gain and related behaviors during pregnancy is necessary to inform behavioral interventions. We used the Theory of Planned Behavior (TPB) to examine pregnant women's perceptions and intentions toward weight gain, physical activity (PA), and nutrition using a mixed methods study design. Women between 20 and 30 weeks gestation (n = 189) were recruited to complete an Internet-based survey. Salient beliefs toward weight gain, PA, and nutrition were captured through open-ended responses and content analyzed into themes. TPB constructs (attitude, subjective norm, perceived behavioral control, intentions) were examined using Pearson correlations and hierarchical linear regression models. Salient beliefs were consistent with the existing literature in non-pregnant populations, with the addition of many pregnancy-specific beliefs. TPB constructs accounted for 23-39 % of the variance in weight gain, PA, and nutrition intentions, and made varying contributions across outcomes. The TPB is a useful framework for examining women's weight-related intentions during pregnancy. Study implications for intervention development are discussed. PMID:26335313

  13. CNTF-Treated Astrocyte Conditioned Medium Enhances Large-Conductance Calcium-Activated Potassium Channel Activity in Rat Cortical Neurons.

    PubMed

    Sun, Meiqun; Liu, Hongli; Xu, Huanbai; Wang, Hongtao; Wang, Xiaojing

    2016-08-01

    Seizure activity is linked to astrocyte activation as well as dysfunctional cortical neuron excitability produced from changes in calcium-activated potassium (KCa) channel function. Ciliary neurotrophic factor-treated astrocyte conditioned medium (CNTF-ACM) can be used to investigate the peripheral effects of activated astrocytes upon cortical neurons. However, CNTF-ACM's effect upon KCa channel activity in cultured cortical neurons has not yet been investigated. Whole-cell patch clamp recordings were performed in rat cortical neurons to evaluate CNTF-ACM's effects upon charybdotoxin-sensitive large-conductance KCa (BK) channel currents and apamin-sensitive small-conductance KCa (SK) channel current. Biotinylation and RT-PCR were applied to assess CNTF-ACM's effects upon the protein and mRNA expression, respectively, of the SK channel subunits SK2 and SK3 and the BK channel subunits BKα1 and BKβ3. An anti-fibroblast growth factor-2 (FGF-2) monoclonal neutralizing antibody was used to assess the effects of the FGF-2 component of CNTF-ACM. CNTF-ACM significantly increased KCa channel current density, which was predominantly attributable to gains in BK channel activity (p < 0.05). CNTF-ACM produced a significant increase in BKα1 and BKβ3 expression (p < 0.05) but had no significant effect upon SK2 or SK3 expression (p > 0.05). Blocking FGF-2 produced significant reductions in KCa channel current density (p > 0.05) as well as BKα1 and BKβ3 expression in CNTF-ACM-treated neurons (p > 0.05). CNTF-ACM significantly enhances BK channel activity in rat cortical neurons and that FGF-2 is partially responsible for these effects. CNTF-induced astrocyte activation results in secretion of neuroactive factors which may affect neuronal excitability and resultant seizure activity in mammalian cortical neurons. PMID:27097551

  14. Surface polaritons in a negative-index metamaterial with active Raman gain

    NASA Astrophysics Data System (ADS)

    Tan, Chaohua; Huang, Guoxiang

    2015-02-01

    We propose a scheme to realize stable propagation of linear and nonlinear surface polaritons (SPs) by placing a N -type four-level quantum emitters at the interface between a dielectric and a negative-index metamaterial (NIMM). We show that in linear propagation regime SPs can acquire an active Raman gain (ARG) from a pump field and a gain doublet appears in the gain spectrum of a signal field induced by the quantum interference effect from a control field. The ARG can be used not only to completely compensate the Ohmic loss in the NIMM but also to acquire a superluminal group velocity for the SPs. We also show that in the nonlinear propagation regime a huge enhancement of the Kerr nonlinearity of the SPs can be obtained. As a result, ARG-assisted (1 + 1 )- and (2 + 1 )- dimensional superluminal surface polaritonic solitons with extremely low generation power may be produced based on the strong confinement of the electric field at the dielectric-NIMM interface.

  15. Dissociation of bactericidal activity from other functions of activated macrophages in exudates induced by thioglycolate medium.

    PubMed Central

    Spitalny, G L

    1981-01-01

    Macrophages displayed increased spreading, increased Fc-receptor-mediated phagocytosis, and increased secretion of plasminogen activator when collected from the peritoneal cavities of either Listeria-immune mice challenged intraperitoneally 3 days earlier with Listeria or nonimmune mice injected intraperitoneally 3 days earlier with fluid thioglycolate medium. In contrast, macrophages from the thioglycolate-induced peritoneal exudates were severely impaired in vitro in their ability to destroy Listeria. Injection of thioglycolate markedly interfered with the destruction of sublethal intraperitoneal challenge of Listeria, which resulted in nonimmune animals dying of an overwhelming systemic infection. In animals immune to Listeria, injection of thioglycolate delayed the onset of the expression of immunity to an intraperitoneal challenge of bacteria. The thioglycolate-induced suppression of bactericidal activity was determined to be confined to the site of injection. Results of experiments indicated that the colloidal agar in thioglycolate medium was the cause of the impairment of macrophage bactericidal activity. In addition to the impairment of bactericidal activity induced by agar, additional studies showed that an intraperitoneal injection of colloidal agar (0.075% wt/vol) by itself was a sufficient inflammatory stimulus for the accumulation of a large number of host phagocytic cells. Images PMID:6795125

  16. Antenna gain of actively compensated free-space optical communication systems under strong turbulence conditions.

    PubMed

    Juarez, Juan C; Brown, David M; Young, David W

    2014-05-19

    Current Strehl ratio models for actively compensated free-space optical communications terminals do not accurately predict system performance under strong turbulence conditions as they are based on weak turbulence theory. For evaluation of compensated systems, we present an approach for simulating the Strehl ratio with both low-order (tip/tilt) and higher-order (adaptive optics) correction. Our simulation results are then compared to the published models and their range of turbulence validity is assessed. Finally, we propose a new Strehl ratio model and antenna gain equation that are valid for general turbulence conditions independent of the degree of compensation. PMID:24921373

  17. Electron bunching in a Penning trap and accelerating process for CO2 gas mixture active medium

    NASA Astrophysics Data System (ADS)

    Tian, Xiu-Fang; Wu, Cong-Feng; Jia, Qi-Ka

    2015-12-01

    In PASER (particle acceleration by stimulated emission of radiation), in the presence of an active medium incorporated in a Penning trap, moving electrons can become bunched, and as they get enough energy, they escape the trap forming an optical injector. These bunched electrons can enter the next PASER section filled with the same active medium to be accelerated. In this paper, electron dynamics in the presence of a gas mixture active medium incorporated in a Penning trap is analyzed by developing an idealized 1D model. We evaluate the energy exchange occurring as the train of electrons traverses into the next PASER section. The results show that the oscillating electrons can be bunched at the resonant frequency of the active medium. The influence of the trapped time and population inversion are analyzed, showing that the longer the electrons are trapped, the more energy from the medium the accelerated electrons get, and with the increase of population inversion, the decelerated electrons are virtually unchanged but the accelerated electrons more than double their peak energy values. The simulation results show that the gas active medium needs a lower population inversion to bunch the electrons compared to a solid active medium, so the experimental conditions can easily be achieved. Supported by National Natural Science Foundation of China (10675116) and Major State Basic Research Development Programme of China (2011CB808301)

  18. Quantitative observations of cavitation activity in a viscoelastic medium.

    PubMed

    Collin, Jamie R T; Coussios, Constantin C

    2011-11-01

    Quantitative experimental observations of single-bubble cavitation in viscoelastic media that would enable validation of existing models are presently lacking. In the present work, single bubble cavitation is induced in an agar gel using a 1.15 MHz high intensity focused ultrasound transducer, and observed using a focused single-element passive cavitation detection (PCD) transducer. To enable quantitative observations, a full receive calibration is carried out of a spherically focused PCD system by a bistatic scattering substitution technique that uses an embedded spherical scatterer and a hydrophone. Adjusting the simulated pressure received by the PCD by the transfer function on receive and the frequency-dependent attenuation of agar gel enables direct comparison of the measured acoustic emissions with those predicted by numerical modeling of single-bubble cavitation using a modified Keller-Miksis approach that accounts for viscoelasticity of the surrounding medium. At an incident peak rarefactional pressure near the cavitation threshold, period multiplying is observed in both experiment and numerical model. By comparing the two sets of results, an estimate of the equilibrium bubble radius in the experimental observations can be made, with potential for extension to material parameter estimation. Use of these estimates yields good agreement between model and experiment. PMID:22088001

  19. Wakefields Generated by Electron Beams Passing through a Waveguide Loaded with an Active Medium

    SciTech Connect

    Tyukhtin, Andrey; Kanareykin, Alexei; Schoessow, Paul

    2006-11-27

    The wakefields of a relativistic electron beam passing through a waveguide loaded with an active medium with weak resonant dispersion have been considered. For the calculations in this paper the parameters of the medium are those of a solution of fullerene (C60) in a nematic liquid crystal that exhibits activity in the X-band. It was shown that several of the TM accelerating modes can be amplified for the geometries under consideration; structures in which higher order modes are amplified exhibit essential advantages as PASERs. In particular, the amplification of the highest mode occurs in a structure loaded with a rather thick active medium layer that maximizes the energy stored by the active medium.

  20. Differential modulation of activity related to the anticipation of monetary gains and losses across the menstrual cycle.

    PubMed

    Bayer, Janine; Bandurski, Pia; Sommer, Tobias

    2013-11-01

    Estradiol and progesterone interact with the dopaminergic and other neurotransmitter systems that are involved in the processing of rewards. On the systems level, these hormones modulate responses to stimulants as well as neuronal activity related to the anticipation of monetary gains. As different mechanisms might underlie the processing of gains and losses, the current study aims to investigate whether neural correlates of gain and loss anticipation are differentially modulated by menstrual cycle phases. Therefore, young, naturally cycling women were examined by means of functional neuroimaging during performing a modified version of the 'Monetary Incentive Delay' task in the early follicular and in the luteal menstrual cycle phase. During the low hormone early follicular phase, the anticipation of high vs. low gains and losses was associated with activity in a largely overlapping network of brain areas. However, high hormone levels in the luteal phase affected brain activity in these areas differentially during the anticipation of high vs. low gains and losses. In particular, the orbitofrontal cortex showed a reduced sensitivity to gain magnitude, whereas the ventral striatum and the anterior cingulate showed a reduced sensitivity to loss magnitude. In summary, the high amount of progesterone and estradiol in the luteal phase decreased activity related to the anticipation of monetary gains and losses in different brain areas, suggesting that hormones modulate different processes during the anticipation of gain and loss magnitude. PMID:23981052

  1. Individual Differences in Striatum Activity to Food Commercials Predict Weight Gain in Adolescents

    PubMed Central

    Yokum, Sonja; Gearhardt, Ashley N.; Harris, Jennifer L.; Brownell, Kelly D.; Stice, Eric

    2014-01-01

    Objective Adolescents view thousands of food commercials annually, but little is known about how individual differences in neural response to food commercials relate to weight gain. To add to our understanding of individual risk factors for unhealthy weight gain and environmental contributions to the obesity epidemic, we tested the associations between reward region (striatum and orbitofrontal cortex [OFC]) responsivity to food commercials and future change in Body Mass Index (BMI). Design and Methods Adolescents (N = 30) underwent a scan session at baseline while watching a television show edited to include 20 food commercials and 20 non-food commercials. BMI was measured at baseline and 1-year follow-up. Results Activation in the striatum, but not OFC, in response to food commercials relative to non-food commercials and in response to food commercials relative to the television show was positively associated with change in BMI over 1-year follow-up. Baseline BMI did not moderate these effects. Conclusions The results suggest that there are individual differences in neural susceptibility to food advertising. These findings highlight a potential mechanism for the impact of food marketing on adolescent obesity. PMID:25155745

  2. Rhythmic auditory cortex activity at multiple timescales shapes stimulus-response gain and background firing.

    PubMed

    Kayser, Christoph; Wilson, Caroline; Safaai, Houman; Sakata, Shuzo; Panzeri, Stefano

    2015-05-20

    The phase of low-frequency network activity in the auditory cortex captures changes in neural excitability, entrains to the temporal structure of natural sounds, and correlates with the perceptual performance in acoustic tasks. Although these observations suggest a causal link between network rhythms and perception, it remains unknown how precisely they affect the processes by which neural populations encode sounds. We addressed this question by analyzing neural responses in the auditory cortex of anesthetized rats using stimulus-response models. These models included a parametric dependence on the phase of local field potential rhythms in both stimulus-unrelated background activity and the stimulus-response transfer function. We found that phase-dependent models better reproduced the observed responses than static models, during both stimulation with a series of natural sounds and epochs of silence. This was attributable to two factors: (1) phase-dependent variations in background firing (most prominent for delta; 1-4 Hz); and (2) modulations of response gain that rhythmically amplify and attenuate the responses at specific phases of the rhythm (prominent for frequencies between 2 and 12 Hz). These results provide a quantitative characterization of how slow auditory cortical rhythms shape sound encoding and suggest a differential contribution of network activity at different timescales. In addition, they highlight a putative mechanism that may implement the selective amplification of appropriately timed sound tokens relative to the phase of rhythmic auditory cortex activity. PMID:25995464

  3. Lossless Airy Surface Polaritons in a Metamaterial via Active Raman Gain

    NASA Astrophysics Data System (ADS)

    Zhang, Qi; Tan, Chaohua; Huang, Guoxiang

    2016-02-01

    We propose a scheme to realize a lossless propagation of linear and nonlinear Airy surface polaritons (SPs) via active Raman gain (ARG). The system we suggest is a planar interface superposed by a negative index metamaterial (NIMM) and a dielectric, where three-level quantum emitters are doped. By using the ARG from the quantum emitters and the destructive interference effect between the electric and magnetic responses from the NIMM, we show that not only the Ohmic loss of the NIMM but also the light absorption of the quantum emitters can be completely eliminated. As a result, non-diffractive Airy SPs may propagate for very long distance without attenuation. We also show that the Kerr nonlinearity of the system can be largely enhanced due to the introduction of the quantum emitters and hence lossless Airy surface polaritonic solitons with very low power can be generated in the system.

  4. Lossless Airy Surface Polaritons in a Metamaterial via Active Raman Gain.

    PubMed

    Zhang, Qi; Tan, Chaohua; Huang, Guoxiang

    2016-01-01

    We propose a scheme to realize a lossless propagation of linear and nonlinear Airy surface polaritons (SPs) via active Raman gain (ARG). The system we suggest is a planar interface superposed by a negative index metamaterial (NIMM) and a dielectric, where three-level quantum emitters are doped. By using the ARG from the quantum emitters and the destructive interference effect between the electric and magnetic responses from the NIMM, we show that not only the Ohmic loss of the NIMM but also the light absorption of the quantum emitters can be completely eliminated. As a result, non-diffractive Airy SPs may propagate for very long distance without attenuation. We also show that the Kerr nonlinearity of the system can be largely enhanced due to the introduction of the quantum emitters and hence lossless Airy surface polaritonic solitons with very low power can be generated in the system. PMID:26891795

  5. Differential Classical Conditioning Selectively Heightens Response Gain of Neural Population Activity in Human Visual Cortex

    PubMed Central

    Song, Inkyung; Keil, Andreas

    2015-01-01

    Neutral cues, after being reliably paired with noxious events, prompt defensive engagement and amplified sensory responses. To examine the neurophysiology underlying these adaptive changes, we quantified the contrast-response function of visual cortical population activity during differential aversive conditioning. Steady-state visual evoked potentials (ssVEPs) were recorded while participants discriminated the orientation of rapidly flickering grating stimuli. During each trial, luminance contrast of the gratings was slowly increased and then decreased. Right-tilted gratings (CS+) were paired with loud white noise but left-tilted gratings (CS−) were not. The contrast-following waveform envelope of ssVEPs showed selective amplification of the CS+ only during the high-contrast stage of the viewing epoch. Findings support the notion that motivational relevance, learned in a time frame of minutes, affects vision through a response gain mechanism. PMID:24981277

  6. Lossless Airy Surface Polaritons in a Metamaterial via Active Raman Gain

    PubMed Central

    Zhang, Qi; Tan, Chaohua; Huang, Guoxiang

    2016-01-01

    We propose a scheme to realize a lossless propagation of linear and nonlinear Airy surface polaritons (SPs) via active Raman gain (ARG). The system we suggest is a planar interface superposed by a negative index metamaterial (NIMM) and a dielectric, where three-level quantum emitters are doped. By using the ARG from the quantum emitters and the destructive interference effect between the electric and magnetic responses from the NIMM, we show that not only the Ohmic loss of the NIMM but also the light absorption of the quantum emitters can be completely eliminated. As a result, non-diffractive Airy SPs may propagate for very long distance without attenuation. We also show that the Kerr nonlinearity of the system can be largely enhanced due to the introduction of the quantum emitters and hence lossless Airy surface polaritonic solitons with very low power can be generated in the system. PMID:26891795

  7. Development of active porous medium filters based on plasma textiles

    SciTech Connect

    Kuznetsov, Ivan A.; Saveliev, Alexei V.; Rasipuram, Srinivasan; Kuznetsov, Andrey V.; Brown, Alan; Jasper, Warren

    2012-05-15

    Inexpensive, flexible, washable, and durable materials that serve as antimicrobial filters and self-decontaminating fabrics are needed to provide active protection to people in areas regularly exposed to various biohazards, such as hospitals and bio research labs working with pathogens. Airlines and cruise lines need such material to combat the spread of infections. In households these materials can be used in HVAC filters to fight indoor pollution, which is especially dangerous to people suffering from asthma. Efficient filtering materials are also required in areas contaminated by other types of hazardous dust particulates, such as nuclear dust. The primary idea that guided the undertaken study is that a microplasma-generating structure can be embedded in a textile fabric to generate a plasma sheath (''plasma shield'') that kills bacterial agents coming in contact with the fabric. The research resulted in the development of a plasma textile that can be used for producing new types of self-decontaminating garments, fabrics, and filter materials, capable of activating a plasma sheath that would filter, capture, and destroy any bacteriological agent deposited on its surface. This new material relies on the unique antimicrobial and catalytic properties of cold (room temperature) plasma that is benign to people and does not cause thermal damage to many polymer textiles, such as Nomex and polypropylene. The uniqueness of cold plasma as a disinfecting agent lies in the inability of bacteria to develop resistance to plasma exposure, as they can for antibiotics. Plasma textiles could thus be utilized for microbial destruction in active antimicrobial filters (for continuous decontamination and disinfection of large amounts of air) as well as in self-decontaminating surfaces and antibacterial barriers (for example, for creating local antiseptic or sterile environments around wounds and burns).

  8. Development of active porous medium filters based on plasma textiles

    NASA Astrophysics Data System (ADS)

    Kuznetsov, Ivan A.; Saveliev, Alexei V.; Rasipuram, Srinivasan; Kuznetsov, Andrey V.; Brown, Alan; Jasper, Warren

    2012-05-01

    Inexpensive, flexible, washable, and durable materials that serve as antimicrobial filters and self-decontaminating fabrics are needed to provide active protection to people in areas regularly exposed to various biohazards, such as hospitals and bio research labs working with pathogens. Airlines and cruise lines need such material to combat the spread of infections. In households these materials can be used in HVAC filters to fight indoor pollution, which is especially dangerous to people suffering from asthma. Efficient filtering materials are also required in areas contaminated by other types of hazardous dust particulates, such as nuclear dust. The primary idea that guided the undertaken study is that a microplasma-generating structure can be embedded in a textile fabric to generate a plasma sheath ("plasma shield") that kills bacterial agents coming in contact with the fabric. The research resulted in the development of a plasma textile that can be used for producing new types of self-decontaminating garments, fabrics, and filter materials, capable of activating a plasma sheath that would filter, capture, and destroy any bacteriological agent deposited on its surface. This new material relies on the unique antimicrobial and catalytic properties of cold (room temperature) plasma that is benign to people and does not cause thermal damage to many polymer textiles, such as Nomex and polypropylene. The uniqueness of cold plasma as a disinfecting agent lies in the inability of bacteria to develop resistance to plasma exposure, as they can for antibiotics. Plasma textiles could thus be utilized for microbial destruction in active antimicrobial filters (for continuous decontamination and disinfection of large amounts of air) as well as in self-decontaminating surfaces and antibacterial barriers (for example, for creating local antiseptic or sterile environments around wounds and burns).

  9. Zeno inhibition of polarization rotation in an optically active medium

    NASA Astrophysics Data System (ADS)

    Gonzalo, Isabel; Porras, Miguel A.; Luis, Alfredo

    2015-07-01

    We describe an experiment in which the rotation of the polarization of light propagating in an optically active water solution of D-fructose tends to be inhibited by frequent monitoring whether the polarization remains unchanged. This is an example of the Zeno effect that has remarkable pedagogical interest because of its conceptual simplicity, easy implementation, low cost, and because the same the Zeno effect holds at classical and quantum levels. An added value is the demonstration of the Zeno effect beyond typical idealized assumptions in a practical setting with real polarizers.

  10. Rhodopsin determinants for transducin activation: a gain-of-function approach.

    PubMed

    Natochin, Michael; Gasimov, Karim G; Moussaif, Mustapha; Artemyev, Nikolai O

    2003-09-26

    Three cytoplasmic loops in the G protein-coupled receptor rhodopsin, C2, C3, and C4, have been implicated as key sites for binding and activation of the visual G protein transducin. Non-helical portions of the C2- and C3-loops and the cytoplasmic helix-8 from the C4 loop were targeted for a "gain-of-function" mutagenesis to identify rhodopsin residues critical for transducin activation. Mutant opsins with residues 140-148 (C2-loop), 229-244 (C3-loop), or 310-320 (C4-loop) substituted by poly-Ala sequences of equivalent lengths served as templates for mutagenesis. The template mutants with poly-Ala substitutions in the C2- and C3-loops formed the 500-nm absorbing pigments but failed to activate transducin. Reverse substitutions of the Ala residues by rhodopsin residues have been generated in each of the templates. Significant ( approximately 50%) restoration of the rhodopsin/transducin coupling was achieved with re-introduction of residues Cys140/Lys141 and Arg147/Phe148 into the C2 template. The reverse substitutions of the C3-loop residues Thr229/Val230 and Ser240/Thr242/Thr243/Gln244 produced a pigment with a full capacity for transducin activation. The C4 template mutant was unable to bind 11-cis-retinal, and the presence of Asn310/Lys311 was required for correct folding of the protein. Subsequent mutagenesis of the C4-loop revealed the role of Phe313 and Met317. On the background of Asn310/Lys311, the inclusion of Phe313 and Met317 produced a mutant pigment with the potency of transducin activation equal to that of the wild-type rhodopsin. Overall, our data support the role of the three cytoplasmic loops of rhodopsin and suggest that residues adjacent to the transmembrane helices are most important for transducin activation. PMID:12860986

  11. GABAergic neural activity involved in salicylate-induced auditory cortex gain enhancement.

    PubMed

    Lu, J; Lobarinas, E; Deng, A; Goodey, R; Stolzberg, D; Salvi, R J; Sun, W

    2011-08-25

    Although high doses of sodium salicylate impair cochlear function, it paradoxically enhances sound-evoked activity in the auditory cortex (AC) and augments acoustic startle reflex responses, neural and behavioral metrics associated with hyperexcitability and hyperacusis. To explore the neural mechanisms underlying salicylate (SS)-induced hyperexcitability and "increased central gain," we examined the effects of GABA receptor agonists and antagonists on SS-induced hyperexcitability in the AC and startle reflex responses. Consistent with our previous findings, local or systemic application of SS significantly increased the amplitude of sound-evoked AC neural activity, but generally reduced spontaneous activity in the AC. Systemic injection of SS also significantly increased the acoustic startle reflex. S-baclofen or R-baclofen, GABA-B agonists, which suppressed sound-evoked AC neural firing rate and local field potentials, also suppressed the SS-induced enhancement of the AC field potential and the acoustic startle reflex. Local application of vigabatrin, which enhances GABA concentration in the brain, suppressed the SS-induced enhancement of AC firing rate. Systemic injection of vigabatrin also reduced the SS-induced enhancement of acoustic startle reflex. Collectively, these results suggest that the sound-evoked behavioral and neural hyperactivity induced by SS may arise from a SS-induced suppression of GABAergic inhibition in the AC. PMID:21664433

  12. An active loudness model suggesting tinnitus as increased central noise and hyperacusis as increased nonlinear gain

    PubMed Central

    Zeng, Fan-Gang

    2012-01-01

    The present study uses a systems engineering approach to delineate the relationship between tinnitus and hyperacusis as a result of either hearing loss in the ear or an imbalanced state in the brain. Specifically examined is the input–output function, or loudness growth as a function of intensity in both normal and pathological conditions. Tinnitus reduces the output dynamic range by raising the floor, while hyperacusis reduces the input dynamic range by lowering the ceiling or sound tolerance level. Tinnitus does not necessarily steepen the loudness growth function but hyperacusis always does. An active loudness model that consists of an expansion stage following a compression stage can account for these key properties in tinnitus and hyperacusis loudness functions. The active loudness model suggests that tinnitus is a result of increased central noise, while hyperacusis is due to increased nonlinear gain. The active loudness model also generates specific predictions on loudness growth in tinnitus, hyperacusis, hearing loss or any combinations of the three conditions. These predictions need to be verified by experimental data and have explicit implications for treatment of tinnitus and hyperacusis. PMID:22641191

  13. Tumor-selective mitochondrial network collapse induced by atmospheric gas plasma-activated medium

    PubMed Central

    Saito, Kosuke; Asai, Tomohiko; Fujiwara, Kyoko; Sahara, Junki; Koguchi, Haruhisa; Fukuda, Noboru; Suzuki-Karasaki, Miki; Soma, Masayoshi; Suzuki-Karasaki, Yoshihiro

    2016-01-01

    Non-thermal atmospheric gas plasma (AGP) exhibits cytotoxicity against malignant cells with minimal cytotoxicity toward normal cells. However, the mechanisms of its tumor-selective cytotoxicity remain unclear. Here we report that AGP-activated medium increases caspase-independent cell death and mitochondrial network collapse in a panel of human cancer cells, but not in non-transformed cells. AGP irradiation stimulated reactive oxygen species (ROS) generation in AGP-activated medium, and in turn the resulting stable ROS, most likely hydrogen peroxide (H2O2), activated intracellular ROS generation and mitochondrial ROS (mROS) accumulation. Culture in AGP-activated medium resulted in cell death and excessive mitochondrial fragmentation and clustering, and these responses were inhibited by ROS scavengers. AGP-activated medium also increased dynamin-related protein 1-dependent mitochondrial fission in a tumor-specific manner, and H2O2 administration showed similar effects. Moreover, the vulnerability of tumor cells to mitochondrial network collapse appeared to result from their higher sensitivity to mROS accumulation induced by AGP-activated medium or H2O2. The present findings expand our previous observations on death receptor-mediated tumor-selective cell killing and reinforce the importance of mitochondrial network remodeling as a powerful target for tumor-selective cancer treatment. PMID:26942565

  14. Tumor-selective mitochondrial network collapse induced by atmospheric gas plasma-activated medium.

    PubMed

    Saito, Kosuke; Asai, Tomohiko; Fujiwara, Kyoko; Sahara, Junki; Koguchi, Haruhisa; Fukuda, Noboru; Suzuki-Karasaki, Miki; Soma, Masayoshi; Suzuki-Karasaki, Yoshihiro

    2016-04-12

    Non-thermal atmospheric gas plasma (AGP) exhibits cytotoxicity against malignant cells with minimal cytotoxicity toward normal cells. However, the mechanisms of its tumor-selective cytotoxicity remain unclear. Here we report that AGP-activated medium increases caspase-independent cell death and mitochondrial network collapse in a panel of human cancer cells, but not in non-transformed cells. AGP irradiation stimulated reactive oxygen species (ROS) generation in AGP-activated medium, and in turn the resulting stable ROS, most likely hydrogen peroxide (H2O2), activated intracellular ROS generation and mitochondrial ROS (mROS) accumulation. Culture in AGP-activated medium resulted in cell death and excessive mitochondrial fragmentation and clustering, and these responses were inhibited by ROS scavengers. AGP-activated medium also increased dynamin-related protein 1-dependent mitochondrial fission in a tumor-specific manner, and H2O2 administration showed similar effects. Moreover, the vulnerability of tumor cells to mitochondrial network collapse appeared to result from their higher sensitivity to mROS accumulation induced by AGP-activated medium or H2O2. The present findings expand our previous observations on death receptor-mediated tumor-selective cell killing and reinforce the importance of mitochondrial network remodeling as a powerful target for tumor-selective cancer treatment. PMID:26942565

  15. Neuronal medium that supports basic synaptic functions and activity of human neurons in vitro.

    PubMed

    Bardy, Cedric; van den Hurk, Mark; Eames, Tameji; Marchand, Cynthia; Hernandez, Ruben V; Kellogg, Mariko; Gorris, Mark; Galet, Ben; Palomares, Vanessa; Brown, Joshua; Bang, Anne G; Mertens, Jerome; Böhnke, Lena; Boyer, Leah; Simon, Suzanne; Gage, Fred H

    2015-05-19

    Human cell reprogramming technologies offer access to live human neurons from patients and provide a new alternative for modeling neurological disorders in vitro. Neural electrical activity is the essence of nervous system function in vivo. Therefore, we examined neuronal activity in media widely used to culture neurons. We found that classic basal media, as well as serum, impair action potential generation and synaptic communication. To overcome this problem, we designed a new neuronal medium (BrainPhys basal + serum-free supplements) in which we adjusted the concentrations of inorganic salts, neuroactive amino acids, and energetic substrates. We then tested that this medium adequately supports neuronal activity and survival of human neurons in culture. Long-term exposure to this physiological medium also improved the proportion of neurons that were synaptically active. The medium was designed to culture human neurons but also proved adequate for rodent neurons. The improvement in BrainPhys basal medium to support neurophysiological activity is an important step toward reducing the gap between brain physiological conditions in vivo and neuronal models in vitro. PMID:25870293

  16. Dehydrated Hereditary Stomatocytosislinked to gain-of-function mutations in mechanically activated PIEZO1 ion channels

    PubMed Central

    Albuisson, Juliette; Murthy, Swetha E.; Bandell, Michael; Coste, Bertrand; Louis-dit-Picard, Hélène; Mathur, Jayanti; Fénéant-Thibault, Madeleine; Tertian, Gérard; de Jaureguiberry, Jean-Pierre; Syfuss, Pierre-Yves; Cahalan, Stuart; Garçon, Loic; Toutain, Fabienne; Rohrlich, Pierre Simon; Delaunay, Jean; Picard, Véronique; Jeunemaitre, Xavier; Patapoutian, Ardem

    2013-01-01

    Dehydrated hereditary stomatocytosis (DHS) is a genetic condition with defective red blood cell (RBC) membrane properties that causes an imbalance in intracellular cation concentrations. Recently, two missense mutations inthe mechanically activated PIEZO1(FAM38A) ion channel were associated with DHS. However, it is not known how these mutations affect PIEZO1 function. Here, by combining linkage analysis and whole-exome sequencing in a large pedigree and Sanger sequencing in two additional kindreds and 11 unrelated DHS cases, we identifythree novel missense mutations and one recurrent duplication in PIEZO1, demonstrating that it is the major gene for DHS. All the DHS-associated mutations locate at C-terminal half of PIEZO1. Remarkably, we find that all PIEZO1 mutations give rise to mechanically activated currents that inactivate more slowly than wild-type currents. This gain-of-function PIEZO1 phenotype provides insight that helps to explain the increased permeability of cations in RBCs of DHS patients. Our findings also suggest a new role for mechanotransduction in RBC biology and pathophysiology. PMID:23695678

  17. Fusing Passive and Active Sensed Images to Gain Infrared-Textured 3d Models

    NASA Astrophysics Data System (ADS)

    Weinmann, M.; Hoegner, L.; Leitloff, J.; Stilla, U.; Hinz, S.; Jutzi, B.

    2012-07-01

    Obtaining a 3D description of man-made and natural environments is a basic task in Computer Vision, Photogrammetry and Remote Sensing. New active sensors provide the possibility of capturing range information by images with a single measurement. With this new technique, image-based active ranging is possible which allows for capturing dynamic scenes, e.g. with moving pedestrians or moving vehicles. The currently available range imaging devices usually operate within the close-infrared domain to capture range and furthermore active and passive intensity images. Depending on the application, a 3D description with additional spectral information such as thermal-infrared data can be helpful and offers new opportunities for the detection and interpretation of human subjects and interactions. Therefore, thermal-infrared data combined with range information is promising. In this paper, an approach for mapping thermal-infrared data on range data is proposed. First, a camera calibration is carried out for the range imaging system (PMD[vision] CamCube 2.0) and the thermal-infrared system (InfraTec VarioCAM hr). Subsequently, a registration of close-infrared and thermal infrared intensity images derived from different sensor devices is performed. In this context, wavelength independent properties are selected in order to derive point correspondences between the different spectral domains. Finally, the thermal infrared images are enhanced with information derived from data acquired with the range imaging device and the enhanced IR texture is projected onto the respective 3D point cloud data for gaining appropriate infrared-textured 3D models. The feasibility of the proposed methodology is demonstrated for an experimental setup which is well-suited for investigating these proposed possibilities. Hence, the presented work is a first step towards the development of methods for combined thermal-infrared and range representation.

  18. Evaluation of the effects of a plasma activated medium on cancer cells

    NASA Astrophysics Data System (ADS)

    Mohades, S.; Laroussi, M.; Sears, J.; Barekzi, N.; Razavi, H.

    2015-12-01

    The interaction of low temperature plasma with liquids is a relevant topic of study to the field of plasma medicine. This is because cells and tissues are normally surrounded or covered by biological fluids. Therefore, the chemistry induced by the plasma in the aqueous state becomes crucial and usually dictates the biological outcomes. This process became even more important after the discovery that plasma activated media can be useful in killing various cancer cell lines. Here, we report on the measurements of concentrations of hydrogen peroxide, a species known to have strong biological effects, produced by application of plasma to a minimum essential culture medium. The activated medium is then used to treat SCaBER cancer cells. Results indicate that the plasma activated medium can kill the cancer cells in a dose dependent manner, retain its killing effect for several hours, and is as effective as apoptosis inducing drugs.

  19. Evaluation of the effects of a plasma activated medium on cancer cells

    SciTech Connect

    Mohades, S.; Laroussi, M. Sears, J.; Barekzi, N.; Razavi, H.

    2015-12-15

    The interaction of low temperature plasma with liquids is a relevant topic of study to the field of plasma medicine. This is because cells and tissues are normally surrounded or covered by biological fluids. Therefore, the chemistry induced by the plasma in the aqueous state becomes crucial and usually dictates the biological outcomes. This process became even more important after the discovery that plasma activated media can be useful in killing various cancer cell lines. Here, we report on the measurements of concentrations of hydrogen peroxide, a species known to have strong biological effects, produced by application of plasma to a minimum essential culture medium. The activated medium is then used to treat SCaBER cancer cells. Results indicate that the plasma activated medium can kill the cancer cells in a dose dependent manner, retain its killing effect for several hours, and is as effective as apoptosis inducing drugs.

  20. LASERS: Efficient chemical oxygen — iodine laser with a high total pressure of the active medium

    NASA Astrophysics Data System (ADS)

    Zagidullin, M. V.; Nikolaev, V. D.; Svistun, M. I.; Khvatov, N. A.; Heiger, G. D.; Madden, T. J.

    2001-01-01

    A new concept of obtaining a high total pressure of the active medium of a chemical oxygen — iodine laser (OIL) is proposed and verified. The nozzle unit of the laser consists of the alternating vertical arrays of cylindrical nozzles to produce high-pressure nitrogen jets, plane slotted nozzles for the flow of O2(1Δ) oxygen, and vertical arrays of cylindrical nozzles to inject the N2 — I2 mixture between the first two streams. For a molar chlorine flow rate of 39.2 mmol s-1, the output power was 700 W and the chemical efficiency was 19.7 %. The combined use of the ejector nozzle unit proposed to obtain the active medium and a super-sonic diffuser allows a significant simplification of the ejection system for the exhaust active medium of the OIL.

  1. Persistence or Change in Leisure-Time Physical Activity Habits and Waist Gain During Early Adulthood: A Twin-Study

    PubMed Central

    Rottensteiner, Mirva; Pietiläinen, Kirsi H.; Kaprio, Jaakko; Kujala, Urho M.

    2014-01-01

    Objective To determine the relationship between persistence or change in leisure-time physical activity habits and waist gain among young adults. Design and Methods Population-based cohort study among 3383 Finnish twin individuals (1578 men) from five birth cohorts (1975–1979), who answered questionnaires at mean ages of 24.4 y (SD 0.9) and 33.9 y (SD 1.2), with reported self-measured waist circumference. Persistence or change in leisure-time physical activity habits was defined based on thirds of activity metabolic equivalent h/day during follow-up (mean 9.5 y; SD 0.7). Results Decreased activity was linked to greater waist gain compared to increased activity (3.6 cm, P<0.001 for men; 3.1 cm, P<0.001 for women). Among same-sex activity discordant twin pairs, twins who decreased activity gained an average 2.8 cm (95%CI 0.4 to 5.1, P=0.009) more waist than their co-twins who increased activity (n=85 pairs); among MZ twin pairs (n=43), the difference was 4.2 cm (95%CI 1.2 to 7.2, P=0.008). Conclusions Among young adults, an increase in leisure-time physical activity or staying active during a decade of follow-up was associated with less waist gain, but any decrease in activity level, regardless baseline activity, led to waist gain that was similar to that associated with being persistently inactive. PMID:24839266

  2. Gaining Proficiency through Task-Based Activities in the Portuguese Classroom (Beginning and Intermediate Year Case Studies)

    ERIC Educational Resources Information Center

    Jones-Kellogg, Rebecca

    2015-01-01

    This paper describes a task-based activity used at the United States Military Academy, in their first- through third-semester Portuguese language sequence "Proficiencies" (Proficiências). The stand-alone task-based activity can be an effective tool in gaining foreign-language proficiency at even the lowest levels of classroom instruction…

  3. Phosphorylation of Mutationally Introduced Tyrosine in the Activation Loop of HER2 Confers Gain-of-Function Activity

    PubMed Central

    Hu, Zexi; Wan, Xiaobo; Hao, Rui; Zhang, Heng; Li, Li; Li, Lin; Xie, Qiang; Wang, Peng; Gao, Yibo; Chen, She; Wei, Min; Luan, Zhidong; Zhang, Aiqun; Huang, Niu; Chen, Liang

    2015-01-01

    Amplification, overexpression, and somatic mutation of the HER2 gene have been reported to play a critical role in tumorigenesis of various cancers. The HER2 H878Y mutation was recently reported in 11% of hepatocellular carcinoma (HCC) patients. However, its functional impact on the HER2 protein and its role in tumorigenesis has not been determined. Here, we show that HER2 H878Y is a gain-of-function mutation. Y878 represents a phosphorylation site, and phospho-Y878 interacts with R898 residue to stabilize the active conformation of HER2, thereby enhancing its kinase activity. H878Y mutant is transforming and the transformed cells are sensitive to HER2 kinase inhibitors. Thus, our study reveals the following novel mechanism underlying the tumorigenic function of the HER2 H878Y mutation: the introduction of a tyrosine residue into the kinase activation loop via mutagenesis modulates the conformation of the kinase, thereby enhancing its activity. PMID:25853726

  4. Gain-of-Function Mutant p53 Promotes Cell Growth and Cancer Cell Metabolism via Inhibition of AMPK Activation

    PubMed Central

    Zhou, Ge; Wang, Jiping; Zhao, Mei; Xie, Tong-Xin; Tanaka, Noriaki; Sano, Daisuke; Patel, Ameeta A.; Ward, Alexandra M; Sandulache, Vlad; Jasser, Samar A.; Skinner, Heath D.; Fitzgerald, Alison Lea; Osman, Abdullah A.; Wei, Yongkun; Xia, Xuefeng; Songyang, Zhou; Mills, Gordon B.; Hung, Mien-Chie; Caulin, Carlos; Liang, Jiyong; Myers, Jeffrey N.

    2014-01-01

    SUMMARY Many mutant p53 proteins (mutp53s) exert oncogenic gain-of-function (GOF) properties, but the mechanisms mediating these functions remain poorly defined. We show here that GOF mutp53s inhibit AMP-activated protein kinase (AMPK) signaling in head and neck cancer cells. Conversely, downregulation of GOF mutp53s enhances AMPK activation under energy stress, decreasing the activity of the anabolic factors acetyl-CoA carboxylase and ribosomal protein S6 and inhibiting aerobic glycolytic potential and invasive cell growth. Under conditions of energy stress, GOF mutp53s, but not wild-type p53, preferentially bind to the AMPKα subunit and inhibit AMPK activation. Given the importance of AMPK as an energy sensor and tumor suppressor that inhibits anabolic metabolism, our findings reveal that direct inhibition of AMPK activation is an important mechanism through which mutp53s can gain oncogenic function. PMID:24857548

  5. Development of a differential medium for bile salt hydrolase-active Lactobacillus spp.

    PubMed Central

    Dashkevicz, M P; Feighner, S D

    1989-01-01

    An agar plate assay was developed to detect bile salt hydrolase activity in lactobacilli. On Lactobacillus-selective MRS or Rogosa SL medium supplemented with taurodeoxycholic, taurocholic, or taurochenodeoxycholic acids, bile salt hydrolysis was manifested at two intensities: (i) the formation of precipitate halos around colonies or (ii) the formation of opaque granular white colonies. Sixty-six lactobacilli were tested for bile salt hydrolase activity by both the plate assay and a sensitive radiochemical assay. No false-positive or false-negative results were detected by the plate assay. Based on results of experiments with Eubacterium lentum and Bacteroides species, the plate assay was dependent on two factors: (i) the presence of bile salt hydrolytic activity and (ii) the ability of the organism to sufficiently acidify the medium to protonate free bile acids. The availability of a differential medium for determination of bile salt hydrolase activity will provide a rapid method for determining shifts in a specific functional activity of intestinal Lactobacillus species and provide a rapid screening capability for identifying bile salt hydrolase-deficient mutants. The latter application should allow bile salt hydrolase activity to be used as a marker enzyme in genetic experiments. Images PMID:2705765

  6. Gaining A Geological Perspective Through Active Learning in the Large Lecture Classroom

    NASA Astrophysics Data System (ADS)

    Kapp, J. L.; Richardson, R. M.; Slater, S. J.

    2008-12-01

    NATS 101 A Geological Perspective is a general education course taken by non science majors. We offer 600 seats per semester, with four large lecture sections taught by different faculty members. In the past we have offered optional once a week study groups taught by graduate teaching assistants. Students often feel overwhelmed by the science and associated jargon, and many are prone to skipping lectures altogether. Optional study groups are only attended by ~50% of the students. Faculty members find the class to be a lot of work, mainly due to the grading it generates. Activities given in lecture are often short multiple choice or true false assignments, limiting the depth of understanding we can evaluate. Our students often lack math and critical thinking skills, and we spend a lot of time in lecture reintroducing ideas students should have already gotten from the text. In summer 2007 we were funded to redesign the course. Our goals were to 1) cut the cost of running the course, and 2) improve student learning. Under our redesign optional study groups were replaced by once a week mandatory break out sessions where students complete activities that have been introduced in lecture. Break out sessions substitute for one hour of lecture, and are run by undergraduate preceptors and graduate teaching assistants (GTAs). During the lecture period, lectures themselves are brief with a large portion of the class devoted to active learning in small groups. Weekly reading quizzes are submitted via the online course management system. Break out sessions allow students to spend more time interacting with their fellow students, undergraduate preceptors, and GTAs. They get one on one help in break out sessions on assignments designed to enhance the lecture material. The active lecture format means less of their time is devoted to listening passively to a lecture, and more time is spent peer learning an interacting with the instructor. Completing quizzes online allows students

  7. Noise-induced effects in an active medium with periodic boundary conditions

    NASA Astrophysics Data System (ADS)

    Slepnev, A. V.; Shepelev, I. A.; Vadivasova, T. E.

    2014-01-01

    A model of an active medium with periodic boundary conditions in which the elementary cell is represented by a FitzHugh-Nagumo oscillator has been studied. Depending on the system parameters, the elementary cell can occur in either auto-oscillatory or excitable state. In both cases, an autonomous medium in the absence of noise performs sustained oscillations and exhibits the phenomenon of multistability. A method for diagnostics of the character of medium with the aid of external noise is proposed, specific features in behavior of the system near the point of transition from the excitable to auto-oscillatory state are considered, and the phenomena of coherent resonance and noise-induced switching are described.

  8. Continuous cultivation of Arthrospira platensis using exhausted medium treated with granular activated carbon

    NASA Astrophysics Data System (ADS)

    Morocho-Jácome, Ana Lucía; Mascioli, Guilherme Favaro; Sato, Sunao; Carvalho, João Carlos Monteiro de

    2015-03-01

    Reusing culture medium of Arthrospira platensis is quite important in large scale production because its inappropriate disposal could exacerbate problems of environmental pollution. This study evaluates the suitability of using different quantities of exhausted Schlösser medium after continuous treatment using granular activated carbon (GAC) with a residence time (T) of 2 h for A. platensis growth in continuous cultivation. A tubular photobioreactor (PBR) and urea as cheap nitrogen source were used, taking as response variables kinetic parameters and biomass composition. The removal of both organic matter and pigment (OMR and PgR, respectively) was measured to evaluate the efficiency of the treatment process. This treatment process yielded high values of OMR (73.7 ± 0.1%) and PgR (52.4 ± 0.4%) using 75% treated medium, thereby A. platensis biomass with high protein content (42.0 ± 0.6%), 1568 ± 15 mg/L cell concentration under steady-state conditions and 941 mg/L d cell productivity. This alternative to simultaneous treatment with GAC for reuse of Schlösser medium in continuous cultivation could ensure no diminution in either cell productivity or protein content in A. platensis cultivation using tubular PBR with 65% reduction in medium culture costs.

  9. Steps Ahead: Adaptation of physical activity and dietary guidelines for reducing unhealthy weight gain in the Lower Misissippi Delta

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The purpose of our study was to test the effectiveness of adapting the Dietary Guidelines for Americans (2010) (DG), with and without a physical activity (PA) component, in reducing weight gain in the Lower Mississippi Delta region (LMD) of the United States. A sample of 121 White and African-Americ...

  10. The Effects of Activity and Gain Based Virtual Material on Student's Success, Permanency and Attitudes towards Science Lesson

    ERIC Educational Resources Information Center

    Tas, Erol

    2015-01-01

    The main objective of this study is to research the effects of a student gains and activity based virtual material on students' success, permanence and attitudes towards science lesson, developed for science and technology lesson 6th grade "Systems in our body" unit. The study, which had a quasi-experimental design, was conducted with…

  11. 78 FR 74125 - Agency Information Collection Activities; Comment Request; Measuring Educational Gain in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-10

    ... Reporting System for Adult Education AGENCY: Department of Education (ED), Office of Vocational and Adult... available to the public for any reason. SUPPLEMENTARY INFORMATION: The Department of Education (ED), in... of Collection: Measuring Educational Gain in the National Reporting System for Adult Education....

  12. 20 CFR 416.972 - What we mean by substantial gainful activity.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... consider activities like taking care of yourself, household tasks, hobbies, therapy, school attendance... work activity that involves doing significant physical or mental activities. Your work may...

  13. 20 CFR 416.972 - What we mean by substantial gainful activity.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... consider activities like taking care of yourself, household tasks, hobbies, therapy, school attendance... work activity that involves doing significant physical or mental activities. Your work may...

  14. 20 CFR 416.972 - What we mean by substantial gainful activity.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... consider activities like taking care of yourself, household tasks, hobbies, therapy, school attendance... work activity that involves doing significant physical or mental activities. Your work may...

  15. 20 CFR 416.972 - What we mean by substantial gainful activity.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... consider activities like taking care of yourself, household tasks, hobbies, therapy, school attendance... work activity that involves doing significant physical or mental activities. Your work may...

  16. 20 CFR 416.972 - What we mean by substantial gainful activity.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... consider activities like taking care of yourself, household tasks, hobbies, therapy, school attendance... work activity that involves doing significant physical or mental activities. Your work may...

  17. Evaluation of antimicrobial activity of probiotic bacteria against Salmonella enterica subsp. enterica serovar typhimurium 1344 in a common medium under different environmental conditions.

    PubMed

    Marianelli, Cinzia; Cifani, Noemi; Pasquali, Paolo

    2010-10-01

    The importance of probiotics in human nutrition has been gaining recognition in recent years. These organisms have been shown to promote human health by enhancing immunological and digestive functions and fighting respiratory tract infections. We propose an improved in vitro model for the study of probiotic antimicrobial activity against enteropathogens, by attempting to re-create, in a common culture medium, environmental growth conditions comparable to those present in the small intestine. A preliminary experiment was carried out in order to find a culture medium able to support both probiotics and pathogens. This was done with the aim of obtaining correct assessment of the interaction under shared growth conditions. BHI medium was selected as the common culture medium and was therefore used in antimicrobial activity assays. The interactions between Salmonella 1344 and Lactobacillus rhamnosus and Lactobacillus reuteri were then assessed at different pH and oxygen availability conditions mimicking the small intestinal environment. L. rhamnosus GG ATCC 53103 (LGG) had the strongest antimicrobial effect, in particular under anaerobic conditions and at lower pH levels. Its antagonistic activity involved both lactic acid and secreted non-lactic acid molecules. Our findings suggest that each probiotic strain has an optimum range of action and should therefore be thoroughly investigated to optimize its use. PMID:20600855

  18. Brillouin Lasing with a Reduced Self-Pulsing Characteristic Using a Short-Length Erbium-Doped Fiber as the Nonlinear Gain Medium

    NASA Astrophysics Data System (ADS)

    Zarei, A.; Z. R. R. Rosdin, R.; M. Ali, N.; H., Ahmad; W. Harun, S.

    2014-05-01

    A single-wavelength Brillouin laser is demonstrated by using a 3-m-long erbium doped fiber (EDF) in a ring cavity. The EDF is used to provide both nonlinear and linear gains to generate a stimulated Brillouin scattering (SBS) and to amplify the generated SBS, respectively. The Brillouin erbium fiber laser (BEFL) operates at 1561.5 nm, where the operating wavelength is up-shifted by 0.08nm from the Brillouin pump. The operation wavelength is also tunable within 1560.6-1562.6 nm. The BEFL also shows a self-pulsing characteristic with repetition of 66.7 kHz when the BP is set around the threshold pump power of 13mW. Compared to the conventional Brillouin fiber laser with a long cavity length, the proposed BEFL exhibits a significantly lower amplitude of pulse. This laser has many potential applications, such as in optical communication and sensors.

  19. Risperidone-induced weight gain and reduced locomotor activity in juvenile female rats: The role of histaminergic and NPY pathways.

    PubMed

    Lian, Jiamei; De Santis, Michael; He, Meng; Deng, Chao

    2015-01-01

    Second generation antipsychotic drugs (SGAs) such as risperidone are increasingly prescribed (mostly for off-label use) to children and adolescents for treating various mental disorders. SGAs cause serious weight gain/obesity and other metabolic side-effects. This study aimed to establish an animal model of risperidone-induced weight gain in female juvenile rats, and to investigate the effects of risperidone on the expression of hypothalamic histaminergic H1 receptors (H1R) and neuropeptides, and their association with weight gain. Female Sprague Dawley rats were treated orally with risperidone (0.3mg/kg, 3 times/day) or vehicle (control) starting from postnatal day (PD) 23 (±1 day) for 3 weeks (a period corresponding to the childhood-adolescent period in humans). In the female juvenile rats, risperidone treatment increased food intake and body weight gain, which started to appear after 12 days' treatment. Risperidone also significantly decreased the locomotor activity of the female rats. Consistently, risperidone significantly elevated mRNA expression of hypothalamic H1R, neuropeptide Y (NPY), and agouti-related peptide (AgRP) compared to controls, and H1R and NPY levels were correlated with risperidone enhanced weight gain and food intake in the female juvenile rats. However, risperidone did not affect hypothalamic proopiomelanocortin (POMC) and cocaine- and amphetamine-regulated transcript (CART) mRNA expression. Therefore, these results suggested that risperidone elevated appetite and body weight gain in juveniles via regulation of the hypothalamic H1R, NPY and AgRP pathways, as well as by reducing activity. PMID:25782398

  20. Subtherapeutic levels of antibiotics in poultry feeds and their effects on weight gain, feed efficiency, and bacterial cholyltaurine hydrolase activity.

    PubMed Central

    Feighner, S D; Dashkevicz, M P

    1987-01-01

    A radiochemical method was developed to estimate cholyltaurine hydrolase potentials and rates of cholyltaurine hydrolysis in chicken intestinal homogenates. This method was used to monitor the effects of antibiotic feed additives on cholyltaurine hydrolase activity. Avoparcin, bacitracin methylenedisalisylic acid, efrotomycin, lincomycin, penicillin G procaine, and virginiamycin improved rate of weight gain and feed conversion of chicks and decreased cholyltaurine hydrolase activity in ileal homogenates relative to those of nonmedicated control birds. The results provided the first evidence that feeding selected antibiotics at subtherapeutic levels can affect bile acid-transforming enzymes in small-intestinal homogenates. The inverse relationship between growth performance and cholyltaurine hydrolase activity raises the possibility that specific inhibitors of this enzyme may promote weight gain and feed conversion in livestock and thereby reduce or eliminate the need for antibiotic feed additives. PMID:3566269

  1. Relationship between Sociodemographics, Dietary Intake, and Physical Activity with Gestational Weight Gain among Pregnant Women in Rafsanjan City, Iran

    PubMed Central

    Ebrahimi, Fatemeh; Tabatabaei, Seyed Zia; Fathollahi, Mahmood Sheikh; Mun, Chan Yoke; Nazari, Mozhgan

    2015-01-01

    ABSTRACT Gestational weight gain (GWG) is a determinant of health and nutrition of mothers and offspring. However, many factors associated with GWG are not completely understood. The present study assessed the relationship between sociodemographics, dietary intake, and physical activity with GWG in 308 Iranian pregnant women attending government healthcare centres in Rafsanjan city, Iran. Women gained an average of 12.87±3.57 kg during pregnancy while 54% did not gain weight within the Institute of Medicine (IOM)-recommended range. Univariate logistic models showed that gestaional weight gain was related to age, pre-pregnancy body mass index (BMI), energy intake, and sitting time. Cumulative logit model showed positive relationship between age (p=0.0137) and pre-pregnancy BMI (p<0.0001) with GWG. All pregnant women should be counselled on achieving the reccomended GWG to prevent adverse maternal and prenatal outcomes. Pre-pregnancy and gestational nutritional status and physical activity should be emphasized in antenatal care. PMID:25995733

  2. Conditioned medium from alternatively activated macrophages induce mesangial cell apoptosis via the effect of Fas

    SciTech Connect

    Huang, Yuan; Luo, Fangjun; Li, Hui; Jiang, Tao; Zhang, Nong

    2013-11-15

    During inflammation in the glomerulus, the proliferation of myofiroblast-like mesangial cells is commonly associated with the pathological process. Macrophages play an important role in regulating the growth of resident mesangial cells in the glomeruli. Alternatively activated macrophage (M2 macrophage) is a subset of macrophages induced by IL-13/IL-4, which is shown to play a repair role in glomerulonephritis. Prompted by studies of development, we performed bone marrow derived macrophage and rat mesangial cell co-culture study. Conditioned medium from IL-4 primed M2 macrophages induced rat mesangial cell apoptosis. The pro-apoptotic effect of M2 macrophages was demonstrated by condensed nuclei stained with Hoechst 33258, increased apoptosis rates by flow cytometry analysis and enhanced caspase-3 activation by western blot. Fas protein was up-regulated in rat mesangial cells, and its neutralizing antibody ZB4 partly inhibited M2 macrophage-induced apoptosis. The up-regulated arginase-1 expression in M2 macrophage also contributed to this apoptotic effect. These results indicated that the process of apoptosis triggered by conditioned medium from M2 macrophages, at least is partly conducted through Fas in rat mesangial cells. Our findings provide compelling evidence that M2 macrophages control the growth of mesangial cells in renal inflammatory conditions. - Highlights: • Conditioned-medium from M2 macrophages induces rat mesangial cell (MsC) apoptosis. • M2 macrophage conditioned medium exerts its pro-apoptotic effects via Fas ligand. • Arginase-1 activity in M2 macrophages plays a role in inducing apoptosis in rat MsC.

  3. Electrochemical assay of α-glucosidase activity and the inhibitor screening in cell medium.

    PubMed

    Zhang, Juan; Liu, Ying; Wang, Xiaonan; Chen, Yangyang; Li, Genxi

    2015-12-15

    An electrochemical method is established in this work for the assay of α-glucosidase activity and the inhibitor screening through one-step displacement reaction, which can be directly used in cell medium. The displacement reaction can be achieved via strong binding of 4-aminophenyl-α-D-glucopyranoside (pAPG)/magnetic nanoparticles (MNPs) to pyrene boric acid (PBA) immobilized on the surface of graphite electrode (GE), compared to that of dopamine (DA)/sliver nanoparticles (AgNPs). Since α-glucosidase can specifically catalyze MNPs/pAPG into MNPs/pAP which has no binding capacity with PBA, the activity of both isolated and membrane bound enzyme can be well evaluated by using this proposed method. Meanwhile, signal amplification can be accomplished via the immobilization of DA at the outer layer of AgNPs, and the accuracy can be strengthened through magnetic separation. Moreover, this method can also be utilized for inhibitor screening not only in the medium containing the enzyme but also in cell medium. With good precision and accuracy, it may be extended to other proteases and their inhibitors as well. PMID:26201984

  4. Gain-Scheduled Approximations to H-Infinity Controllers for the F/A-18 Active Aeroelastic Wing

    NASA Technical Reports Server (NTRS)

    Lind, Rick

    1999-01-01

    The Active Aeroelastic Wing will demonstrate technologies related to aeroservoelastic effects such as wing twist and load minimization. This paper presents a control design based on H-infinity synthesis that simultaneously considers the multiple objectives associated with handling qualities, actuator limitations, and loads. The controller is realized as a filter and gain set approximation to a state-space H-infinity controller. This approximation allows scheduling of the controller over a flight envelope.

  5. Longevity of optically activated, high gain GaAs photoconductive semiconductor switches

    SciTech Connect

    Loubriel, G.M.; Zutavern, F.J.; Mar, A.

    1997-08-01

    The longevity of high gain GaAs photoconductive semiconductor switches (PCSS) has been extended to well over 10 million pulses by reducing the density of carriers at the semiconductor to metal interface. This was achieved by reducing the density in the vertical and lateral directions. The first was achieved by varying the spatial distribution of the trigger light thereby widening the current filaments that are characteristic of the high gain switches. The authors reduced the carrier density in the vertical direction by using ion implantation. These results were obtained for currents of about 10 A, current duration of 3.5 ns, and switched voltage of {approximately}2 kV. At currents of {approximately}70 A, the switches last for 0.6 million pulses. In order to improve the performance at high currents new processes such as deep diffusion and epitaxial growth of contacts are being pursued. To guide this effort the authors measured a carrier density of 6 x 10{sup 18} electrons (or holes)/cm{sup 3} in filaments that carry a current of 5 A.

  6. Longevity improvement of optically activated, high gain GaAs photoconductive semiconductor switches

    SciTech Connect

    MAR,ALAN; LOUBRIEL,GUILLERMO M.; ZUTAVERN,FRED J.; O'MALLEY,MARTIN W.; HELGESON,WESLEY D.; BROWN,DARWIN JAMES; HJALMARSON,HAROLD P.; BACA,ALBERT G.

    2000-03-02

    The longevity of high gain GaAs photoconductive semiconductor switches (PCSS) has been extended to over 100 million pulses at 23A, and over 100 pulses at 1kA. This is achieved by improving the ohmic contacts by doping the semi-insulating GaAs underneath the metal, and by achieving a more uniform distribution of contact wear across the entire switch by distributing the trigger light to form multiple filaments. This paper will compare various approaches to doping the contacts, including ion implantation, thermal diffusion, and epitaxial growth. The device characterization also includes examination of the filament behavior using open-shutter, infra-red imaging during high gain switching. These techniques provide information on the filament carrier densities as well as the influence that the different contact structures and trigger light distributions have on the distribution of the current in the devices. This information is guiding the continuing refinement of contact structures and geometries for further improvements in switch longevity.

  7. Pregnant women’s perceptions of weight gain, physical activity, and nutrition using Theory of Planned Behavior constructs

    PubMed Central

    Wilcox, Sara; Liu, Jihong; Blair, Steven N.; Pate, Russell R.

    2016-01-01

    A better understanding of women’s perceptions of weight gain and related behaviors during pregnancy is necessary to inform behavioral interventions. We used the Theory of Planned Behavior (TPB) to examine pregnant women’s perceptions and intentions toward weight gain, physical activity (PA), and nutrition using a mixed methods study design. Women between 20 and 30 weeks gestation (n = 189) were recruited to complete an Internet-based survey. Salient beliefs toward weight gain, PA, and nutrition were captured through open-ended responses and content analyzed into themes. TPB constructs (attitude, subjective norm, perceived behavioral control, intentions) were examined using Pearson correlations and hierarchical linear regression models. Salient beliefs were consistent with the existing literature in non-pregnant populations, with the addition of many pregnancy-specific beliefs. TPB constructs accounted for 23–39 % of the variance in weight gain, PA, and nutrition intentions, and made varying contributions across outcomes. The TPB is a useful framework for examining women’s weight-related intentions during pregnancy. Study implications for intervention development are discussed. PMID:26335313

  8. Method and system for edge cladding of laser gain media

    SciTech Connect

    Bayramian, Andrew James; Caird, John Allyn; Schaffers, Kathleen Irene

    2014-03-25

    A gain medium operable to amplify light at a gain wavelength and having reduced transverse ASE includes an input surface and an output surface opposing the input surface. The gain medium also includes a central region including gain material and extending between the input surface and the output surface along a longitudinal optical axis of the gain medium. The gain medium further includes an edge cladding region surrounding the central region and extending between the input surface and the output surface along the longitudinal optical axis of the gain medium. The edge cladding region includes the gain material and a dopant operable to absorb light at the gain wavelength.

  9. A phospholipid-deacylating system of bacteria active in a frozen medium.

    PubMed Central

    Hazlewood, G P; Dawson, R M

    1976-01-01

    A phosphatidylcholine-deacylating system present in a Butyrivibrio species (probably fibrisolvens) shows appreciable activity at low temperatures with a maximum hydrolysis rate at--10 degrees C. 2. The rate at--10 degrees C is higher than at 39 degrees C unless the system at the latter temperature is stimulated by adding oleic acid or sodium dodecyl sulphate. 3. The low-temperature phospholipase activity has an absolute requirement for thiol reagents, e.g. cysteine, dithiothreitol or mercaptoethanol. 4. Ca2+, Mg2+ and Mn2+ stimulate the activity up to 10 mM, but EDTA inhibits; higher concentrations of Ca2+ also inhibit. 5. The enhancement of activity at low temperatures appears not to be associated with a crystalline change in the hydrated phospholipid substrate, but depends on the formation of a solid phase in the incubation medium which brings the substrate and bacterial cells into juxtaposition or causes fusion. Images PLATE 1 PMID:1259714

  10. Study on the activation of styrene-based shape memory polymer by medium-infrared laser light

    SciTech Connect

    Leng Jinsong; Yu Kai; Lan Xin; Zhang Dawei; Liu Yanju

    2010-03-15

    This paper demonstrates the feasibility of shape memory polymer (SMP) activation by medium-infrared laser light. Medium-infrared light is transmitted by an optical fiber embedded in the SMP matrix, and the shape recovery process and temperature distribution are recorded by an infrared camera. Light-induced SMP exhibits potential applications in biomedicines and flexible displays.

  11. Effects of temperature and medium composition on inhibitory activities of gossypol-related compounds against aflatoxigenic fungi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effects of temperature and medium composition on growth/aflatoxin inhibitory activities of gossypol, gossypolone and apogossypolone against Aspergillus flavus and A. parasiticus were investigated. The compounds were tested in a Czapek agar medium at 25 C, 31 C and 37 C at a concentration of 100 µg ...

  12. 75 FR 5804 - Small and Medium-Sized Enterprises: U.S. and EU Export Activities, and Barriers and Opportunities...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-04

    ... published in the Federal Registers of October 28, 2009 (74 FR 55581); December 1, 2009 (74 FR 62812); and... COMMISSION Small and Medium-Sized Enterprises: U.S. and EU Export Activities, and Barriers and Opportunities Experienced by U.S. Firms and Small and Medium-Sized Enterprises: Characteristics and Performance...

  13. Possibilities of increasing the pumping efficiency of solid active medium laser generators by optimizing the pumping cavity profile

    NASA Astrophysics Data System (ADS)

    Dontu, O.; Ganatsios, S.; Alexandrescu, N.

    2008-03-01

    The paper presents some design elements concerning the optical pumping cavities of the laser generators with active solid medium, as well as the way of increasing their performance. We start from the fact that the laser cavity is a closed optical system, where the active laser medium and the pumping source are conjugated, in order to achieve a maximum concentration of the light flux of the pumping source towards the active medium. We discuss the simple elliptical section laser pumping cavities (with one pumping lamp) and triple elliptical (with three lamps), also presenting a series on calculus nomograms, very useful to those who design the laser generation optical pumping cavities.

  14. Self-propulsion and interactions of catalytic particles in a chemically active medium

    NASA Astrophysics Data System (ADS)

    Banigan, Edward J.; Marko, John F.

    2016-01-01

    Enzymatic "machines," such as catalytic rods or colloids, can self-propel and interact by generating gradients of their substrates. We theoretically investigate the behaviors of such machines in a chemically active environment where their catalytic substrates are continuously synthesized and destroyed, as occurs in living cells. We show how the kinetic properties of the medium modulate self-propulsion and pairwise interactions between machines, with the latter controlled by a tunable characteristic interaction range analogous to the Debye screening length in an electrolytic solution. Finally, we discuss the effective force arising between interacting machines and possible biological applications, such as partitioning of bacterial plasmids.

  15. Nanocrystals of medium soluble actives--novel concept for improved dermal delivery and production strategy.

    PubMed

    Zhai, Xuezhen; Lademann, Jürgen; Keck, Cornelia M; Müller, Rainer H

    2014-08-15

    After use in oral pharmaceutical products, nanocrystals are meanwhile applied to improve the dermal penetration of cosmetic actives (e.g. rutin, hesperidin) and of drugs. By now, nanocrystals are only dermally applied made from poorly soluble actives. The novel concept is to formulate nanocrystals also from medium soluble actives, and to apply a dermal formulation containing additionally nanocrystals. The nanocrystals should act as fast dissolving depot, increase saturation solubility and especially accumulate in the hair follicles, to further increase skin penetration. Caffeine was used as model compound with relevance to market products, and a particular process was developed for the production of caffeine nanocrystals to overcome the supersaturation related effect of crystal growth and fiber formation - typical with medium soluble compounds. It is based on low energy milling (pearl milling) in combination with low dielectric constant dispersion media (water-ethanol or ethanol-propylene glycol mixtures) and optimal stabilizers. Most successful was Carbopol(®) 981 (e.g. 20% caffeine in ethanol-propylene glycol 3:7 with 2% Carbopol, w/w). Nanocrystals with varied sizes can now be produced in a controlled process e.g. 660 nm (optimal for hair follicle accumulation) to 250 nm (optimal for fast dissolution). The short term test proved stability over 2 months of the present formulation being sufficient to perform in vivo testing of the novel concept. PMID:24813782

  16. Doped Contacts for High-Longevity Optically Activated, High Gain GaAs Photoconductive Semiconductor Switches

    SciTech Connect

    MAR,ALAN; LOUBRIEL,GUILLERMO M.; ZUTAVERN,FRED J.; O'MALLEY,MARTIN W.; HELGESON,WESLEY D.; BROWN,DARWIN JAMES; HJALMARSON,HAROLD P.; BACA,ALBERT G.; THORNTON,R.L.; DONALDSON,R.D.

    1999-12-17

    The longevity of high gain GaAs photoconductive semiconductor switches (PCSS) has been extended to over 100 million pulses. This was achieved by improving the ohmic contacts through the incorporation of a doped layer that is very effective in the suppression of filament formation, alleviating current crowding. Damage-free operation is now possible with virtually infinite expected lifetime at much higher current levels than before. The inherent damage-free current capacity of the bulk GaAs itself depends on the thickness of the doped layers and is at least 100A for a dopant diffusion depth of 4pm. The contact metal has a different damage mechanism and the threshold for damage ({approx}40A) is not further improved beyond a dopant diffusion depth of about 2{micro}m. In a diffusion-doped contact switch, the switching performance is not degraded when contact metal erosion occurs, unlike a switch with conventional contacts. This paper will compare thermal diffusion and epitaxial growth as approaches to doping the contacts. These techniques will be contrasted in terms of the fabrication issues and device characteristics.

  17. Doped Contacts for High-Longevity Optically Activated, High Gain GaAs Photoconductive Semiconductor Switches

    SciTech Connect

    Baca, A.G.; Brown, D.J.; Donaldson, R.D.; Helgeson, W.D.; Hjalmarson, H.P.; Loubriel, G.M.; Mar, A.; O'Malley, M.W.; Thornton, R.L.; Zutavern, F.J.

    1999-08-05

    The longevity of high gain GaAs photoconductive semiconductor switches (PCSS) has been extended to over 50 million pulses. This was achieved by improving the ohmic contacts through the incorporation of a doped layer beneath the PCSS contacts which is very effective in the suppression of filament formation and alleviating current crowding to improve the longevity of PCSS. Virtually indefinite, damage-free operation is now possible at much higher current levels than before. The inherent damage-free current capacity of the switch depends on the thickness of the doped layers and is at least 100A for a dopant diffusion depth of 4pm. The contact metal has a different damage mechanism and the threshold for damage ({approximately}40A) is not further improved beyond a dopant diffusion depth of about 2{micro}m. In a diffusion-doped contact switch, the switching performance is not degraded when contact metal erosion occurs. This paper will compare thermal diffusion and epitaxial growth as approaches to doping the contacts. These techniques will be contrasted in terms of the fabrication issues and device characteristics.

  18. Arctigenin Inhibits Adipogenesis by Inducing AMPK Activation and Reduces Weight Gain in High-Fat Diet-Induced Obese Mice.

    PubMed

    Han, Yo-Han; Kee, Ji-Ye; Park, Jinbong; Kim, Hye-Lin; Jeong, Mi-Young; Kim, Dae-Seung; Jeon, Yong-Deok; Jung, Yunu; Youn, Dong-Hyun; Kang, JongWook; So, Hong-Seob; Park, Raekil; Lee, Jong-Hyun; Shin, Soyoung; Kim, Su-Jin; Um, Jae-Young; Hong, Seung-Heon

    2016-09-01

    Although arctigenin (ARC) has been reported to have some pharmacological effects such as anti-inflammation, anti-cancer, and antioxidant, there have been no reports on the anti-obesity effect of ARC. The aim of this study is to investigate whether ARC has an anti-obesity effect and mediates the AMP-activated protein kinase (AMPK) pathway. We investigated the anti-adipogenic effect of ARC using 3T3-L1 pre-adipocytes and human adipose tissue-derived mesenchymal stem cells (hAMSCs). In high-fat diet (HFD)-induced obese mice, whether ARC can inhibit weight gain was investigated. We found that ARC reduced weight gain, fat pad weight, and triglycerides in HFD-induced obese mice. ARC also inhibited the expression of peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer-binding protein alpha (C/EBPα) in in vitro and in vivo. Furthermore, ARC induced the AMPK activation resulting in down-modulation of adipogenesis-related factors including PPARγ, C/EBPα, fatty acid synthase, adipocyte fatty acid-binding protein, and lipoprotein lipase. This study demonstrates that ARC can reduce key adipogenic factors by activating the AMPK in vitro and in vivo and suggests a therapeutic implication of ARC for obesity treatment. J. Cell. Biochem. 117: 2067-2077, 2016. © 2016 Wiley Periodicals, Inc. PMID:26852013

  19. Different synchronization characteristics of distinct types of traveling waves in a model of active medium with periodic boundary conditions

    NASA Astrophysics Data System (ADS)

    Shepelev, Igor A.; Slepnev, Andrei V.; Vadivasova, Tatiana E.

    2016-09-01

    The model of a one-dimensional active medium, which cells are the FitzHugh-Nagumo oscillators, is studied for periodical boundary conditions. The medium possesses three different regimes in dependence on the parameter values. The regimes correspond to the self-sustained oscillations, excitable dynamics or bistability of the medium cells. Periodic boundary conditions provide the existence of traveling wave modes in all mentioned cases without any deterministic or stochastic excitation. The spatial waveforms and the character of oscillations in time can be similar in the different cases, but the properties of wave modes depend considerably on the medium regime. So, the dispersion characteristics and the synchronization phenomena are essentially different for bistable and excitable media on the one hand, and for the self-sustained oscillatory medium on the other hand. The local and distributed periodic influence on the medium are studied. The phenomenon of the traveling wave frequency locking is observed for all three regimes of the active medium. The comparison of synchronization effects in self-oscillatory, excitable and bistable regimes of the active medium is carried out.

  20. Cell Motility Is Decreased in Macrophages Activated by Cancer Cell-Conditioned Medium

    PubMed Central

    Go, Ahreum; Ryu, Yun-Kyoung; Lee, Jae-Wook; Moon, Eun-Yi

    2013-01-01

    Macrophages play a role in innate immune responses to various foreign antigens. Many products from primary tumors influence the activation and transmigration of macrophages. Here, we investigated a migration of macrophages stimulated with cancer cell culture-conditioned medium (CM). Macrophage activation by treatment with CM of B16F10 cells were judged by the increase in protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX2). The location where macrophages were at 4 h-incubation with control medium or CM was different from where they were at 5 h-incubation in culture dish. Percentage of superimposed macrophages at every 1 h interval was gradually increased by CM treatment as compared to control. Total coverage of migrated track expressed in coordinates was smaller and total distance of migration was shorter in CM-treated macrophages than that in control. Rac1 activity in CM-treated macrophages was also decreased as compared to that in control. When macrophages were treated with CM in the presence of dexamethasone (Dex), an increase in COX2 protein levels, and a decrease in Rac1 activity and total coverage of migration were reversed. In the meanwhile, biphasic changes were detected by Dex treatment in section distance of migration at each time interval, which was more decreased at early time and then increased at later time. Taken together, data demonstrate that macrophage motility could be reduced in accordance with activation in response to cancer cell products. It suggests that macrophage motility could be a novel marker to monitor cancer-associated inflammatory diseases and the efficacy of anti-inflammatory agents. PMID:24404340

  1. Porous, catalytically active palladium nanostructures by tuning nanoparticle interactions in an organic medium

    NASA Astrophysics Data System (ADS)

    Halder, Aditi; Patra, S.; Viswanath, B.; Munichandraiah, N.; Ravishankar, N.

    2011-02-01

    We present a simple template-free method for the synthesis of interconnected hierarchical porous palladium nanostructures by controlling the aggregation of nanoparticles in organic media. The interaction between the nanoparticles is tuned by varying the dielectric constant of the medium consistent with DLVO calculations. The reaction products range from discrete nanoparticles to compact porous clusters with large specific surface areas. The nanoclusters exhibit hierarchical porosity and are found to exhibit excellent activity towards the reduction of 4-nitrophenol into 4-aminophenol and hydrogen oxidation. The method opens up possibilities for synthesizing porous clusters of other functional inorganics in organic media.We present a simple template-free method for the synthesis of interconnected hierarchical porous palladium nanostructures by controlling the aggregation of nanoparticles in organic media. The interaction between the nanoparticles is tuned by varying the dielectric constant of the medium consistent with DLVO calculations. The reaction products range from discrete nanoparticles to compact porous clusters with large specific surface areas. The nanoclusters exhibit hierarchical porosity and are found to exhibit excellent activity towards the reduction of 4-nitrophenol into 4-aminophenol and hydrogen oxidation. The method opens up possibilities for synthesizing porous clusters of other functional inorganics in organic media. Electronic supplementary information (ESI) available: Additional figures of the Pd nanostructures. See DOI: 10.1039/c0nr00640h

  2. Coupled-resonator vertical-cavity lasers with two active gain regions

    DOEpatents

    Fischer, Arthur J.; Choquette, Kent D.; Chow, Weng W.

    2003-05-20

    A new class of coupled-resonator vertical-cavity semiconductor lasers has been developed. These lasers have multiple resonant cavities containing regions of active laser media, resulting in a multi-terminal laser component with a wide range of novel properties.

  3. Geophysical Monitoring of Active Infiltration Experiments for Recharge Estimation: Gains and Pains

    NASA Astrophysics Data System (ADS)

    Noell, U.; Lamparter, A.; Houben, G.; Koeniger, P.; Stoeckl, L.; Guenther, T.

    2014-12-01

    Drinking water supply on the island of Langeoog, North Sea, solely depends on groundwater from a freshwater lens. The correct estimation of the recharge rate is critical for a sustainable use of the resource. Extensive hydrogeological and geophysical studies have revealed differences in groundwater recharge by a factor of two and more between the top of the dunes and the dune valleys. The most convincing proof of these differences in recharge is based on isotope analysis (age dating) but boreholes are scarce and a direct proof of recharge is desired. For this purpose active infiltration experiments are performed and geophysically monitored. Former applications of this method in sand and loess soil gave evidence for the applicability of the geophysical observation when combined with tensiometers installed in situ at depth. These results showed firstly that in sandy soil the water reaches the groundwater table quicker than anticipated due to the water repellent characteristic of the dry sand, inhibiting the lateral spreading of the water. The studies also revealed that in loess preferential flow is initiated by ponding and that sprinkling caused very slow movement of water within the unsaturated zone and the water remained near the surface. On the island of Langeoog field experiments underlined the importance of water repellency on the dune surface, indicating that the rain water runs off superficially into the dune valleys where higher recharge is found. The active infiltration zone of the experiment covers an area of some 7m² and includes steeper parts of the dune. The infiltration will vary depending on rainfall intensity and duration, original water content and vegetation cover. What results can we reliably expect from the active experiment and what additional measurements are required to back up the findings? Results are ambiguous with regard to the quantitative assessment but the processes can be visualized by geophysical monitoring in situ.

  4. Dendritic cells treated with resveratrol during differentiation from monocytes gain substantial tolerogenic properties upon activation

    PubMed Central

    Švajger, Urban; Obermajer, Nataša; Jeras, Matjaž

    2010-01-01

    Resveratrol is a polyphenol that acts on multiple molecular targets important for cell differentiation and activation. Dendritic cells (DCs) are a functionally diverse cell type and represent the most potent antigen-presenting cells of the immune system. In this study, we investigated resveratrol-induced effects on DCs during their differentiation and maturation. Our results show that resveratrol induces DC-associated tolerance, particularly when applied during DC differentiation. Costimulatory molecules CD40, CD80 and CD86 were down-regulated, as was the expression of major histocompatibility complex (MHC) class II molecules. Surface expression of inhibitory immunoglobulin-like transcript 3 (ILT3) and ILT4 molecules was induced, while human leucocyte antigen (HLA)-G expression was not affected. Resveratrol-treated DCs lost the ability to produce interleukin (IL)-12p70 after activation, but had an increased ability to produce IL-10. Such DCs were poor stimulators of allogeneic T cells and had lowered ability to induce CD4+ T-cell migration. Furthermore, treated cells were able to generate allogeneic IL-10-secreting T cells, but were not competent in inducing FoxP3 expression These tolerogenic effects are probably associated with the effect of resveratrol on multiple molecular targets through which it interferes with DC differentiation and nuclear factor (NF)-κB translocation. Our data provide new insights into the molecular and functional mechanisms of the tolerogenic effects that resveratrol exerts on DCs. PMID:20002210

  5. Comparative studies on extracts from Hericium erinaceus by different polarity reagents to gain higher antioxidant activities

    PubMed Central

    JIANG, SHENGJUAN; WANG, YULIANG; ZHANG, XIAOLONG

    2016-01-01

    Hericium erinaceus (H. erinaceus) is a source of exogenous antioxidants that has been traditionally used in China for the prevention and treatment of oxidative stress-associated disease. In the present study, the bioactive compounds of H. erinaceus were extracted with the following eight representative reagents: n-Hexane, xylene, chloroform, anhydrous ether, ethyl acetate, acetone, anhydrous ethanol and distilled water. The in vitro antioxidant activities were also evaluated. All of the extracted compounds exhibited reducing power and scavenging activity against 1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide anion free radicals. In addition, the antioxidant capacities varied with the used chemical reagents and exhibited dose-dependent effects. Extracts from anhydrous ethanol, chloroform and acetone were capable of inhibiting lipid peroxidation. The anhydrous ethanol extracts were observed to have significant levels of antioxidant compounds since they had a strong reducing power, high scavenging rates against DPPH and superoxide anion-free radicals (>90%), and high inhibition rates on lipid peroxidation (>60%). The present study will provide reference data for the antioxidant applications of H. erinaceus in pharmaceutical use and disease prevention. PMID:27347087

  6. Dependence of synchronized bursting activity on medium stirring and the perfusion rate in a cultured network of neurons

    NASA Astrophysics Data System (ADS)

    Heo, Ryoun; Kim, Hyun; Lee, Kyoung J.

    2016-05-01

    A cultured network of neurons coupled with a multi-electrode-array (MEA) recording system has been a useful platform for investigating various issues in neuroscience and engineering. The neural activity supported by the system can be sensitive to environmental fluctuations, for example, in the medium's nutrient composition, ph, and temperature, and to mechanical disturbances, yet this issue has not been the subject. Especially, a normal practice in maintaining neuronal cell cultures involves an intermittent sequence of medium exchanges, typically at a time interval of a few days, and one such sudden medium exchange is unavoidably accompanied by many unintended disturbances. Here, based on a quantitative time-series analysis of synchronized bursting events, we explicitly demonstrate that such a medium exchange can, indeed, bring a huge change in the existing neural activity. Subsequently, we develop a medium perfusion-stirring system and an ideal protocol that can be used in conjunction with a MEA recording system, providing long-term stability. Specifically, we systematically evaluate the effects of medium stirring and perfusion rates. Unexpectedly, even some vigorous mechanical agitations do not have any impacts on neural activity. On the other hand, too much replenishment ( e.g., 1.8 ml/day for a 1.8-ml dish) of neurobasal medium results in an excitotoxicity.

  7. Health/Service Providers' Perspectives on Barriers to Healthy Weight Gain and Physical Activity in Pregnant, Urban First Nations Women.

    PubMed

    Darroch, Francine E; Giles, Audrey R

    2016-01-01

    The purpose of this article is to examine health/service providers' perspectives of barriers to healthy weight gain and physical activity for urban, pregnant First Nations women in Ottawa, Canada. Through the use of semi-structured interviews, we explored 15 health/service providers' perspectives on the complex barriers their clients face. By using a postcolonial feminist lens and a social determinants of health framework, we identified three social determinants of health that the health/service providers believed to have the greatest influence on their clients' weight gain and physical activity during pregnancy: poverty, education, and colonialism. Our findings are then contextualized within existing Statistics Canada and the Ottawa Neighbourhood Study data. We found that health/service providers are in a position to challenge colonial relations of power. We conclude by urging health/service providers, researchers, and policymakers alike to take into consideration the ways in which these social determinants of health and their often synergistic effects affect urban First Nations women during pregnancy. PMID:25779985

  8. Antitumor effect of synergistic contribution of nitrite and hydrogen peroxide in the plasma activated medium

    NASA Astrophysics Data System (ADS)

    Kurake, Naoyuki; Tanaka, Hiromasa; Ishikawa, Kenji; Nakamura, Kae; Kajiyama, Hiroaki; Kikkawa, Fumiaki; Kondo, Takashi; Mizuno, Masaaki; Takeda, Keigo; Kondo, Hiroki; Sekine, Makoto; Hori, Masaru

    2015-09-01

    Non-equilibrium atmospheric pressure plasmas (NEAPP) have been attracted attention in the noble application of cancer therapy. Although good effects of the Plasma-Activated-Medium (PAM) such as the selective antitumor effect and killing effect for the anticancer agent resistant cells were reported, a mechanism of this effect has not been still clarified yet. In this study, we have investigated a contribution of the reactive nitrogen and oxygen species (RNOS) generated in PAM such as hydrogen peroxide and nitrite. Those species generated in the PAM quantitatively measured by light absorbance of commercial regent. Moreover, viable cell count after cell culture with those RNOS intentionally added medium or PAM were also measured by MTS assay. Our NEAPP source generated hydrogen peroxide and nitrite with the generation ratio of 0.35 μM/s and 9.8 μM/s. In those RNOS, hydrogen peroxide has respective antitumor effect. On the other hands, nitrite has no antitumor effect singly. But, synergistically enhance the antitumor effect of hydrogen peroxide. Moreover, this effect of those RNOS also contribute for the selectively cancer killing effect of PAM.

  9. Ag/ZnO heterostructures and their photocatalytic activity under visible light: effect of reducing medium.

    PubMed

    Liu, Yangsi; Wei, Shanghai; Gao, Wei

    2015-04-28

    Decoration of ZnO by Ag is a promising method to improve its photocatalytic activity and extend the photoreactivity to the visible light. In this paper, Ag/ZnO heterostructures have been synthesised by photoreduction in various reducing mediums. When the Ag/ZnO nanocomposite arrays were obtained in the air, only a small amount of Ag was reduced. Ag nanosheets and nanoparticles were formed in the water and attached on the top and side surfaces of ZnO nanorods, forming Ag/ZnO heterostructures with a nano(sheet-rod-particle) multi-level structure. In the mixture of water and ethanol, a large amount of Ag nanoclusters was produced and embedded in the ZnO nanorod arrays. The influence of reducing mediums on the microstructure, morphology, quantity and dispersion of Ag nanostructures was investigated; and the effect of Ag component on the optical properties and visible light driven photocatalytic behaviour of the Ag/ZnO heterostructures was discussed. PMID:25621832

  10. Dermal nanocrystals from medium soluble actives - physical stability and stability affecting parameters.

    PubMed

    Zhai, Xuezhen; Lademann, Jürgen; Keck, Cornelia M; Müller, Rainer H

    2014-09-01

    Nanocrystals are meanwhile applied to increase the dermal penetration of drugs, but were applied by now only to poorly soluble drugs (e.g. 1-10 μg/ml). As a new concept nanocrystals from medium soluble actives were produced, using caffeine as model compound (solubility 16 mg/ml at 20 °C). Penetration should be increased by (a) further increase in solubility and (b) mainly by increased hair follicle targeting of nanocrystals compared to pure solution. Caffeine nanocrystal production in water lead to pronounced crystal growth. Therefore the stability of nanocrystals in water-ethanol (1:9) and ethanol-propylene glycol (3:7) mixtures with lower dielectric constant D was investigated, using various stabilizers. Both mixtures in combination with Carbopol 981 (non-neutralized) yielded stable nanosuspensions over 2 months at 4 °C and room temperature. Storage at 40 °C lead to crystal growth, attributed to too strong solubility increase, supersaturation and Ostwald ripening effects. Stability of caffeine nanocrystals at lower temperatures could not only be attributed to lower solubility, because the solubilities of caffeine in mixtures and in water are not that much different. Other effects such as quantified by reduced dielectric constant D, and specific interactions between dispersion medium and crystal surface seem to play a role. With the 2 mixtures and Carbopol 981, a basic formulation composition for this type of nanocrystals has been established, to be used in the in vivo proof of principle of the new concept. PMID:25016978

  11. Gain control of synaptic response function in cerebellar nuclear neurons by a calcium-activated potassium conductance.

    PubMed

    Feng, Steven Si; Lin, Risa; Gauck, Volker; Jaeger, Dieter

    2013-10-01

    Small conductance Ca(2+)-activated potassium (SK) current provides an important modulator of excitatory synaptic transmission, which undergoes plastic regulation via multiple mechanisms. We examined whether inhibitory input processing is also dependent on SK current in the cerebellar nuclei (CN) where inhibition provides the only route of information transfer from the cerebellar cortical Purkinje cells. We employed dynamic clamping in conjunction with computer simulations to address this question. We found that SK current plays a critical role in the inhibitory synaptic control of spiking output. Specifically, regulation of SK current density resulted in a gain control of spiking output, such that low SK current promoted large output signaling for large inhibitory cell input fluctuations due to Purkinje cell synchronization. In contrast, smaller nonsynchronized Purkinje cell input fluctuations were not amplified. Regulation of SK density in the CN therefore would likely lead to important consequences for the transmission of synchronized Purkinje cell activity to the motor system. PMID:23605187

  12. GQ-16, a Novel Peroxisome Proliferator-activated Receptor γ (PPARγ) Ligand, Promotes Insulin Sensitization without Weight Gain

    PubMed Central

    Amato, Angélica A.; Rajagopalan, Senapathy; Lin, Jean Z.; Carvalho, Bruno M.; Figueira, Ana C. M.; Lu, Jenny; Ayers, Stephen D.; Mottin, Melina; Silveira, Rodrigo L.; Souza, Paulo C. T.; Mourão, Rosa H. V.; Saad, Mário J. A.; Togashi, Marie; Simeoni, Luiz A.; Abdalla, Dulcinéia S. P.; Skaf, Munir S.; Polikparpov, Igor; Lima, Maria C. A.; Galdino, Suely L.; Brennan, Richard G.; Baxter, John D.; Pitta, Ivan R.; Webb, Paul; Phillips, Kevin J.; Neves, Francisco A. R.

    2012-01-01

    The recent discovery that peroxisome proliferator-activated receptor γ (PPARγ) targeted anti-diabetic drugs function by inhibiting Cdk5-mediated phosphorylation of the receptor has provided a new viewpoint to evaluate and perhaps develop improved insulin-sensitizing agents. Herein we report the development of a novel thiazolidinedione that retains similar anti-diabetic efficacy as rosiglitazone in mice yet does not elicit weight gain or edema, common side effects associated with full PPARγ activation. Further characterization of this compound shows GQ-16 to be an effective inhibitor of Cdk5-mediated phosphorylation of PPARγ. The structure of GQ-16 bound to PPARγ demonstrates that the compound utilizes a binding mode distinct from other reported PPARγ ligands, although it does share some structural features with other partial agonists, such as MRL-24 and PA-082, that have similarly been reported to dissociate insulin sensitization from weight gain. Hydrogen/deuterium exchange studies reveal that GQ-16 strongly stabilizes the β-sheet region of the receptor, presumably explaining the compound's efficacy in inhibiting Cdk5-mediated phosphorylation of Ser-273. Molecular dynamics simulations suggest that the partial agonist activity of GQ-16 results from the compound's weak ability to stabilize helix 12 in its active conformation. Our results suggest that the emerging model, whereby “ideal” PPARγ-based therapeutics stabilize the β-sheet/Ser-273 region and inhibit Cdk5-mediated phosphorylation while minimally invoking adipogenesis and classical agonism, is indeed a valid framework to develop improved PPARγ modulators that retain antidiabetic actions while minimizing untoward effects. PMID:22584573

  13. ACTIVE MEDIA: Gain dynamics in a pulsed laser amplifier on CO-He, CO-N2 and CO-O2 gas mixtures

    NASA Astrophysics Data System (ADS)

    Vetoshkin, S. V.; Ionin, Andrei A.; Klimachev, Yu M.; Kozlov, A. Yu; Kotkov, A. A.; Rulev, O. A.; Seleznev, L. V.; Sinitsyn, D. V.

    2007-02-01

    Small-signal gain (SSG) dynamics G(t) in the active medium of a pulsed laser amplifier operating on the v+1→vP(J) vibrational-rotational transitions of the CO molecule, including high (v > 15) vibrational transitions, is studied experimentally. It is demonstrated that as the vibrational number increases from 7 to 31, G changes with time slower, while Gmax decreases in this case by three times. It is found that at a fixed value of v the rate of the SSG rise increases with increasing the rotational number J > 6. It is shown that in oxygen-containing gas mixtures (CO:O2 = 1:19) the value of Gmax at low vibrational levels (for v < 13) can substantially exceed Gmax in mixtures containing nitrogen (CO:N2 = 1:19) instead of oxygen. It is found that the efficiency (47%) of a CO laser on mixtures with a high concentration of oxygen considerably exceeds the efficiency (30%) of a CO laser operating on a nitrogen-containing mixture.

  14. Regulation of Nucleotide Metabolism by Mutant p53 Contributes to its Gain-of-Function Activities

    PubMed Central

    Kollareddy, Madhusudhan; Dimitrova, Elizabeth; Vallabhaneni, Krishna C.; Chan, Adriano; Le, Thuc; Chauhan, Krishna M.; Carrero, Zunamys I.; Ramakrishnan, Gopalakrishnan; Watabe, Kounosuke; Haupt, Ygal; Haupt, Sue; Pochampally, Radhika; Boss, Gerard R.; Romero, Damian G.; Radu, Caius G.; Martinez, Luis A.

    2015-01-01

    SUMMARY Mutant p53 (mtp53) is an oncogene that drives cancer cell proliferation. Here we report that mtp53 associates with the promoters of numerous nucleotide metabolism genes (NMG). Mtp53 knockdown reduces NMG expression and substantially depletes nucleotide pools, which attenuates GTP dependent protein (GTPase) activity and cell invasion. Addition of exogenous guanosine or GTP restores the invasiveness of mtp53 knockdown cells, suggesting that mtp53 promotes invasion by increasing GTP. Additionally, mtp53 creates a dependency on the nucleoside salvage pathway enzyme deoxycytidine kinase (dCK) for the maintenance of a proper balance in dNTP pools required for proliferation. These data indicate that mtp53 harboring cells have acquired a synthetic sick or lethal phenotype relationship with the nucleoside salvage pathway. Finally, elevated expression of NMG correlates with mutant p53 status and poor prognosis in breast cancer patients. Thus, mtp53’s control of nucleotide biosynthesis has both a driving and sustaining role in cancer development. PMID:26067754

  15. When your pain signifies my gain: neural activity while evaluating outcomes based on another person's pain.

    PubMed

    Cui, Fang; Zhu, Xiangru; Gu, Ruolei; Luo, Yue-Jia

    2016-01-01

    The overlap between pain and reward processing pathways leds researchers to hypothesize that there are interactions between them in the human brain. Two hypotheses have been proposed. The "competition hypothesis" posits that reward can reduce pain-related neural activity and vice versa. The "salience hypothesis" suggests that the motivational salience of pain and reward can be mutually reinforced. However, no study has tested these two hypotheses from temporal perspective as we know. In the present study, pictures depicted other people in painful or non-painful situations were used to indicate the valence of outcomes in a gambling task. The event-related potential results revealed an interaction between another person's pain and outcome valence in multiple time stages. Specifically, the amplitudes of the N1 and P3 were enhanced in the win condition compared with the loss condition when the outcome was indicated by painful picture. This interactions between pain and reward support the salience hypothesis but not the competition hypothesis. The present results provide evidence from human subjects that support the salience hypothesis, which claims that observing other people's pain can enhance the salience of reward. PMID:27193060

  16. Is excessive online usage a function of medium or activity? An empirical pilot study

    PubMed Central

    Griffiths, Mark D.; Szabo, Attila

    2014-01-01

    Aims: The purpose of the study was to seek a better insight into whether the online medium or the online activity was more important in relation to excessive online use. It is not clear whether those people who spend excessive amounts of time on the Internet are engaged in general Internet or whether excessive Internet use is linked to specific activities. Methods: Perceived changes in Internet use habits as function of hypothetical accessibility of favorite sites were investigated in young adults. University students (n = 130, mean age = 20.6 years) who had (on average) spent over 20 hours a week on the Internet for at least nine years completed a survey. The most favored online activities and expected quality of life without Internet access were also investigated. Results: Findings revealed that social networking was by far the most popular online activity, and that lack of access to their preferred online activities would drop by 65% (as measured by perceived Internet usage). Approximately one in six participants (16%) claimed they would not even switch on the computer if access to their favorite online activities were unavailable. In relation to a hypothetical question about the quality of life without Internet access, the responses were normally distributed (rather than skewed). Conclusions: These results show that time spent with Internet activity is not random and/or generalized, but appears more focused. Attraction or addiction on Internet to one or more specific behavior(s) may be a better way forward in the quest for better understanding excessive human behavior in the online environment. PMID:25215216

  17. Wave propagation in reconfigurable broadband gain metamaterials at microwave frequencies

    NASA Astrophysics Data System (ADS)

    Fan, Yifeng; Nagarkoti, Deepak S.; Rajab, Khalid Z.; Hao, Yang; Zhang, Hao Chi; Cui, Tie Jun

    2016-05-01

    The wave dispersion characteristics for loop array-based metamaterials were analyzed, based on the general transmission line model of a one-dimensional host medium interacting with a chain of coupled loops. By relating the wave propagation constant and the effective parameters of the coupled host medium, we showed that an active medium embedded with non-Foster loaded loop array can be designed to exhibit broadband negative material parameters with positive gain. Accounting for all interactions, the stability of the active medium was investigated, further yielding necessary design specifications for the non-Foster loads. Subsequently, an experimental demonstration was provided to verify the theoretical analysis, showing that stable reconfigurable broadband gain metamaterials at microwave frequencies can be obtained with proper negative impedance converter design.

  18. Variable susceptibility of ovarian cancer cells to non-thermal plasma-activated medium

    PubMed Central

    UTSUMI, FUMI; KAJIYAMA, HIROAKI; NAKAMURA, KAE; TANAKA, HIROMASA; MIZUNO, MASAAKI; TOYOKUNI, SHINNYA; HORI, MASARU; KIKKAWA, FUMITAKA

    2016-01-01

    Non-thermal atmospheric pressure plasma has been widely studied in recent years in many fields, including cancer treatment. However, its efficiency for inducing apoptosis sometimes varies depending on the cell species and experimental conditions. The aim of this study was to elucidate what causes these differences in responses to plasma treatment. Using four ovarian cancer cell lines, the cell density had a markedly negative impact on the proliferation inhibition rate (PIR) and it was more obvious in OVCAR-3 and NOS2 cells. Furthermore, TOV21G and ES-2 cells were drastically sensitive to plasma-activated medium (PAM) compared with the other two cell lines. We demonstrated that the proportion of reactive oxygen species and cell number had a marked impact on the effect of PAM against ovarian cancer cells. Additionally it was suggested that the morphological features of cells were also closely related PMID:27035127

  19. Variable susceptibility of ovarian cancer cells to non-thermal plasma-activated medium.

    PubMed

    Utsumi, Fumi; Kajiyama, Hiroaki; Nakamura, Kae; Tanaka, Hiromasa; Mizuno, Masaaki; Toyokuni, Shinnya; Hori, Masaru; Kikkawa, Fumitaka

    2016-06-01

    Non-thermal atmospheric pressure plasma has been widely studied in recent years in many fields, including cancer treatment. However, its efficiency for inducing apoptosis sometimes varies depending on the cell species and experimental conditions. The aim of this study was to elucidate what causes these differences in responses to plasma treatment. Using four ovarian cancer cell lines, the cell density had a markedly negative impact on the proliferation inhibition rate (PIR) and it was more obvious in OVCAR-3 and NOS2 cells. Furthermore, TOV21G and ES-2 cells were drastically sensitive to plasma‑activated medium (PAM) compared with the other two cell lines. We demonstrated that the proportion of reactive oxygen species and cell number had a marked impact on the effect of PAM against ovarian cancer cells. Additionally it was suggested that the morphological features of cells were also closely related to the sensitivity of cancer cells to the plasma treatment. PMID:27035127

  20. Chemical properties and antioxidant activity of exopolysaccharides fractions from mycelial culture of Inonotus obliquus in a ground corn stover medium.

    PubMed

    Xiang, Yuling; Xu, Xiangqun; Li, Juan

    2012-10-15

    The medicinal mushroom Inonotus obliquus has been a folk remedy for a long time in East-European and Asian countries. We first reported the enhancement in production and antioxidant activity of exopolysaccharides by I. obliquus culture under lignocellulose decomposition. In this study, the two different sources of exopolysaccharides from the control medium and the lignocellulose (corn stover) containing medium by I. obliquus in submerged fermentation were fractionated and purified by chromatography. The exopolysaccharides from the corn stover-containing medium presented significantly stronger hydroxyl and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity than the control. Three fractions from the control medium and the corn stover-containing medium were isolated respectively. The fraction of DEPL3 from the corn stover-containing medium with the highest protein content (38.3%), mannose content (49.6%), and the lowest molecular weight (29 kDa) had the highest antioxidant activity with the lowest IC50 values. In conclusion, lignocellulose decomposition changed the chemical characterisation and significantly enhanced the antioxidant activity of exopolysaccharide fractions. PMID:23442636

  1. Thermoregulation of water foraging honeybees--balancing of endothermic activity with radiative heat gain and functional requirements.

    PubMed

    Kovac, Helmut; Stabentheiner, Anton; Schmaranzer, Sigurd

    2010-12-01

    Foraging honeybees are subjected to considerable variations of microclimatic conditions challenging their thermoregulatory ability. Solar heat is a gain in the cold but may be a burden in the heat. We investigated the balancing of endothermic activity with radiative heat gain and physiological functions of water foraging Apis mellifera carnica honeybees in the whole range of ambient temperatures (T(a)) and solar radiation they are likely to be exposed in their natural environment in Middle Europe. The mean thorax temperature (T(th)) during foraging stays was regulated at a constantly high level (37.0-38.5 °C) in a broad range of T(a) (3-30 °C). At warmer conditions (T(a)=30-39 °C) T(th) increased to a maximal level of 45.3 °C. The endothermic temperature excess (difference of T(body)-T(a) of living and dead bees) was used to assess the endogenously generated temperature elevation as a correlate of energy turnover. Up to a T(a) of ∼30 °C bees used solar heat gain for a double purpose: to reduce energetic expenditure and to increase T(th) by about 1-3 °C to improve force production of flight muscles. At higher T(a) they exhibited cooling efforts to get rid of excess heat. A high T(th) also allowed regulation of the head temperature high enough to guarantee proper function of the bees' suction pump even at low T(a). This shortened the foraging stays and this way reduced energetic costs. With decreasing T(a) bees also reduced arrival body weight and crop loading to do both minimize costs and optimize flight performance. PMID:20705071

  2. Thermoregulation of water foraging honeybees—Balancing of endothermic activity with radiative heat gain and functional requirements

    PubMed Central

    Kovac, Helmut; Stabentheiner, Anton; Schmaranzer, Sigurd

    2010-01-01

    Foraging honeybees are subjected to considerable variations of microclimatic conditions challenging their thermoregulatory ability. Solar heat is a gain in the cold but may be a burden in the heat. We investigated the balancing of endothermic activity with radiative heat gain and physiological functions of water foraging Apis mellifera carnica honeybees in the whole range of ambient temperatures (Ta) and solar radiation they are likely to be exposed in their natural environment in Middle Europe. The mean thorax temperature (Tth) during foraging stays was regulated at a constantly high level (37.0–38.5 °C) in a broad range of Ta (3–30 °C). At warmer conditions (Ta = 30–39 °C) Tth increased to a maximal level of 45.3 °C. The endothermic temperature excess (difference of Tbody − Ta of living and dead bees) was used to assess the endogenously generated temperature elevation as a correlate of energy turnover. Up to a Ta of ∼30 °C bees used solar heat gain for a double purpose: to reduce energetic expenditure and to increase Tth by about 1–3 °C to improve force production of flight muscles. At higher Ta they exhibited cooling efforts to get rid of excess heat. A high Tth also allowed regulation of the head temperature high enough to guarantee proper function of the bees’ suction pump even at low Ta. This shortened the foraging stays and this way reduced energetic costs. With decreasing Ta bees also reduced arrival body weight and crop loading to do both minimize costs and optimize flight performance. PMID:20705071

  3. Assessment of highly active dune mobility in the medium, short and very short term

    NASA Astrophysics Data System (ADS)

    Navarro, Marina; Muñoz-Pérez, Juan J.; Román-Sierra, Jorge; Tsoar, Haim; Rodríguez, Inmaculada; Gómez-Pina, Gregorio

    2011-06-01

    Dune activity or stability has usually been studied over long time periods; however, this may not reflect changes that occur in the short term, especially for highly active dunefields. Extreme wind conditions that are generated near the Strait of Gibraltar (SW Spain) have given rise to the transgressive Valdevaqueros dunefield. The current work focuses on analyzing the sand drift potential and the evolution of the dune profile in the medium term (months), the short term (days) and the very short term (hours). Topographic data, which were collected with a differential GPS, were interpreted from reconstructed empirical orthogonal functions (EOF). The results showed that generally the dune profile presented shifting morphologies, especially around the crest and brink, and a trend towards migration to a gentler steady state. As a result, the leeward side adopted continuous slope variations during the different survey periods, whereas the windward slope did not undergo any significant change. Lateral and vertical displacements were analyzed during a severe easterly sandstorm, when the dune brink experienced an advance migration rate of 1.75 m in 24 h. Sand transport rates of 25.5-36.5 m 3 m - 1 month - 1 , 22.52 m 3 m - 1 day - 1 and 0.93 m 3 m - 1 h - 1 were measured for the medium term, short term and very short term, respectively. These values were compared to the theoretical sand transport rate for Valdevaqueros dune, based on the classic Bagnold equation as well other more recent formulae, to obtain a ratio between the real and the theoretical rates for each study period. These results together with the sand drift potential (up to 10,000 vector units) demonstrate that Valdevaqueros (Tarifa) is a dunefield with one of the highest sand transport capacities in Europe.

  4. Gain-of-function mutations in the mechanically activated ion channel PIEZO2 cause a subtype of Distal Arthrogryposis

    PubMed Central

    Coste, Bertrand; Houge, Gunnar; Murray, Michael F.; Stitziel, Nathan; Bandell, Michael; Giovanni, Monica A.; Philippakis, Anthony; Hoischen, Alexander; Riemer, Gunnar; Steen, Unni; Steen, Vidar Martin; Mathur, Jayanti; Cox, James; Lebo, Matthew; Rehm, Heidi; Weiss, Scott T.; Wood, John N.; Maas, Richard L.; Sunyaev, Shamil R.; Patapoutian, Ardem

    2013-01-01

    Mechanotransduction, the pathway by which mechanical forces are translated to biological signals, plays important but poorly characterized roles in physiology. PIEZOs are recently identified, widely expressed, mechanically activated ion channels that are hypothesized to play a role in mechanotransduction in mammals. Here, we describe two distinct PIEZO2 mutations in patients with a subtype of Distal Arthrogryposis Type 5 characterized by generalized autosomal dominant contractures with limited eye movements, restrictive lung disease, and variable absence of cruciate knee ligaments. Electrophysiological studies reveal that the two PIEZO2 mutations affect biophysical properties related to channel inactivation: both E2727del and I802F mutations cause the PIEZO2-dependent, mechanically activated currents to recover faster from inactivation, while E2727del also causes a slowing of inactivation. Both types of changes in kinetics result in increased channel activity in response to a given mechanical stimulus, suggesting that Distal Arthrogryposis Type 5 can be caused by gain-of-function mutations in PIEZO2. We further show that overexpression of mutated PIEZO2 cDNAs does not cause constitutive activity or toxicity to cells, indicating that the observed phenotype is likely due to a mechanotransduction defect. Our studies identify a type of channelopathy and link the dysfunction of mechanically activated ion channels to developmental malformations and joint contractures. PMID:23487782

  5. Kinetics of an oxygen - iodine active medium with iodine atoms optically pumped on the 2P1/2 - 2P3/2 transition

    NASA Astrophysics Data System (ADS)

    Zagidullin, M. V.; Malyshev, M. S.; Azyazov, V. N.

    2015-08-01

    The kinetics of the processes occurring in an O2 - I2 - He - H2O gas flow in which photodissociation of molecular iodine at a wavelength close to 500 nm and excitation of atomic iodine on the 2P1/2 - 2P3/2 transition by narrow-band radiation near 1315 nm are implemented successively has been analysed. It is shown that implementation of these processes allows one to form an oxygen - iodine medium with a high degree of dissociation of molecular iodine and a relative content of singlet oxygen O2(a1Δ) exceeding 10%. Having formed a supersonic gas flow with a temperature ~100 K from this medium, one can reach a small-signal gain of about 10-2 cm-1 on the 2P1/2 - 2P3/2 transition in iodine atoms. The specific power per unit flow cross section in the oxygen - iodine laser with this active medium may reach ~100 W cm-2.

  6. High Basal Activity of the PTPN22 Gain-of-Function Variant Blunts Leukocyte Responsiveness Negatively Affecting IL-10 Production in ANCA Vasculitis

    PubMed Central

    Cao, Yali; Yang, Jiajin; Colby, Kerry; Hogan, Susan L.; Hu, Yichun; Jennette, Caroline E.; Berg, Elisabeth A.; Zhang, Youkang; Jennette, J. Charles; Falk, Ronald J.; Preston, Gloria A.

    2012-01-01

    Consequences of expression of the protein tyrosine phosphatase nonreceptor 22 (PTPN22) gain-of-function variant were evaluated in leukocytes from patients with anti-neutrophil cytoplasmic autoantibody (ANCA) disease. The frequency of the gain-of-function allele within the Caucasian patient cohort was 22% (OR 1.45), compared to general American Caucasian population (16.5%, p = 0.03). Examination of the basal phosphatase activity of PTPN22 gain-of-function protein indicated persistently elevated activity in un-stimulated peripheral leukocytes, while basal activity was undetectable in leukocytes from patients without the gain-of-function variant. To examine consequences of persistently high PTPN22 activity, the activation status of ERK and p38 MAPK were analyzed. While moderate levels of activated ERK were observed in controls, it was undetectable in leukocytes expressing PTPN22 gain-of-function protein and instead p38MAPK was up-regulated. IL-10 transcription, reliant on the ERK pathway, was negatively affected. Over the course of disease, patients expressing variant PTPN22 did not show a spike in IL-10 transcription as they entered remission in contrast to controls, implying that environmentally triggered signals were blunted. Sustained activity of PTPN22, due to the gain-of-function mutation, acts as a dominant negative regulator of ERK activity leading to blunted cellular responsiveness to environmental stimuli and expression of protective cytokines. PMID:22880107

  7. GABAA receptor activity shapes the formation of inhibitory synapses between developing medium spiny neurons

    PubMed Central

    Arama, Jessica; Abitbol, Karine; Goffin, Darren; Fuchs, Celine; Sihra, Talvinder S.; Thomson, Alex M.; Jovanovic, Jasmina N.

    2015-01-01

    Basal ganglia play an essential role in motor coordination and cognitive functions. The GABAergic medium spiny neurons (MSNs) account for ~95% of all the neurons in this brain region. Central to the normal functioning of MSNs is integration of synaptic activity arriving from the glutamatergic corticostriatal and thalamostriatal afferents, with synaptic inhibition mediated by local interneurons and MSN axon collaterals. In this study we have investigated how the specific types of GABAergic synapses between the MSNs develop over time, and how the activity of GABAA receptors (GABAARs) influences this development. Isolated embryonic (E17) MSNs form a homogenous population in vitro and display spontaneous synaptic activity and functional properties similar to their in vivo counterparts. In dual whole-cell recordings of synaptically connected pairs of MSNs, action potential (AP)-activated synaptic events were detected between 7 and 14 days in vitro (DIV), which coincided with the shift in GABAAR operation from depolarization to hyperpolarization, as detected indirectly by intracellular calcium imaging. In parallel, the predominant subtypes of inhibitory synapses, which innervate dendrites of MSNs and contain GABAAR α1 or α2 subunits, underwent distinct changes in the size of postsynaptic clusters, with α1 becoming smaller and α2 larger over time, while both the percentage and the size of mixed α1/α2-postsynaptic clusters were increased. When activity of GABAARs was under chronic blockade between 4–7 DIV, the structural properties of these synapses remained unchanged. In contrast, chronic inhibition of GABAARs between 7–14 DIV led to reduction in size of α1- and α1/α2-postsynaptic clusters and a concomitant increase in number and size of α2-postsynaptic clusters. Thus, the main subtypes of GABAergic synapses formed by MSNs are regulated by GABAAR activity, but in opposite directions, and thus appear to be driven by different molecular mechanisms. PMID

  8. High-resolution X-ray spectroscopy of four active galaxies - Probing the intercloud medium

    NASA Technical Reports Server (NTRS)

    Lum, Kenneth S. K.; Canizares, Claude R.; Markert, Thomas H.; Arnaud, Keith A.

    1990-01-01

    The focal plane crystal spectrometer (FPCS) on the Einstein Observatory has been used to perform a high-resolution spectroscopic search for oxygen X-ray line emission from four active galaxies: Fairall 9, Mrk 421, Mrk 501, and PKS 0548 - 322. Specifically, O VIII Ly-alpha and Ly-beta, whose unredshifted energies are 653 and 775 eV, respectively, were sought. No narrow-line emission was detected within the energy bands searched. Upper limits are calculated on the line flux from these sources of 30 eV equivalent width and use a photoionization model to place corresponding upper limits on the densities of diffuse gas surrounding the active nuclei. The upper limits on gas density range from about 0.02-50/cu cm and probe various radial distances from the central source. This is the first time high-resolution X-ray spectroscopy has been used to place constraints on the intercloud medium in active galaxies.

  9. Enhanced esterification activity through interfacial activation and cross-linked immobilization mechanism of Rhizopus oryzae lipase in a nonaqueous medium.

    PubMed

    Kartal, Funda

    2016-07-01

    Interfacial activation via surfactant (Tween 80, Triton X-100) treatment was conducted to improve the esterification activity of Rhizopus oryzae lipase that had undergone immobilization through cross-linked enzyme aggregates (CLEA®) technique. Surfactant pretreated immobilized enzymes exhibited better esterification activity compared to free and non-pretreated immobilized enzyme (Control CLEAs) since higher conversion rates were obtained within shorter times. The superiority of surfactant pretreated CLEAs, especially Tween 80 pretreated CLEAs (T 80 PT CLEAs), were clearly pronounced when longer alcohols were used as substrates. Conversion values exceeded 90% for octyl octanoate, oleyl octanoate and oleyl oleate synthesis with T 80 PT CLEAs whereas Control CLEAs and free enzyme showed no activity. Maximum conversions were achieved in the case equal molars of the substrates or in the case excess of the alcohol to acid in cyclohexane. In solvent free medium containing equal molars of substrates the conversion rates were 85% and 87% with T 80 PT CLEAs respectively for octyl octanoate and oleyl oleate within 2 hours. T 80 PT CLEAs showed 59% of its original activity after 7 consecutive usage for oleyl oleate synthesis. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:899-904, 2016. PMID:27111483

  10. Use of dyes in solid medium for screening ligninolytic activity of selective actinomycetes

    SciTech Connect

    Chahal, D.S.; Kluepfel, D.; Morosoli, R.

    1995-12-31

    Lignin, a three-dimensional biopolymer, not only encrusts the cellulose microfibrils in a sheath-like manner, but is also bonded physically and chemically to the plant polysaccharides. Unless the lignin is depolymerized, solubilized, or removed, the cellulose and hemicelluloses cannot be easily hydrolyzed by respective enzymes for their bioconversion into biofuels and chemicals. By now it has been established that lignin peroxidase (LiP) of white-rot fungus Phanerochaete chrysosporium is responsible for degradation of lignin. It has been reported that LiP is produced during secondary metabolism under carbon or nitrogen limitation by this organism. In literature, usually low yields (per unit volume) of LiP with P. chrysosporium have been reported. The reasons for low yields may be attributed to insufficient nitrogen in production media, which ultimately affects the synthesis of LiP protein. Therefore, it necessitated a search for an organism that can produce a ligninolytic enzyme system during its primary metabolism, without any effect of nitrogen limitation in the fermentation medium and without supply of extra oxygen to the cultures. Glenn and Gold were the first to report that decolorization of polymeric dyes in liquid cultures is related to the lignin degradation system. They demonstrated that like lignin degradation, the decolorization of polymeric dyes by the white-rot basidiomycete P. chrysosporium occurred during secondary metabolism, was suppressed in cultures grown in the presence of high levels of nitrogen, and was strongly dependent on the oxygen concentration in the cultures. The present study was undertaken to establish if certain dyes in solid media could be used to screen ligninolytic activity of selective actinomycetes during their primary metabolism without the limitation of nitrogen in the medium.

  11. Replacing Non-Active Video Gaming by Active Video Gaming to Prevent Excessive Weight Gain in Adolescents

    PubMed Central

    Simons, Monique; Brug, Johannes; Chinapaw, Mai J. M.; de Boer, Michiel; Seidell, Jaap; de Vet, Emely

    2015-01-01

    Objective The aim of the current study was to evaluate the effects of and adherence to an active video game promotion intervention on anthropometrics, sedentary screen time and consumption of sugar-sweetened beverages and snacks among non-active video gaming adolescents who primarily were of healthy weight. Methods We assigned 270 gaming (i.e. ≥2 hours/week non-active video game time) adolescents randomly to an intervention group (n = 140) (receiving active video games and encouragement to play) or a waiting-list control group (n = 130). BMI-SDS (SDS = adjusted for mean standard deviation score), waist circumference-SDS, hip circumference and sum of skinfolds were measured at baseline, at four and ten months follow-up (primary outcomes). Sedentary screen time, physical activity, consumption of sugar-sweetened beverages and snacks, and process measures (not at baseline) were assessed with self-reports at baseline, one, four and ten months follow-up. Multi-level-intention to treat-regression analyses were conducted. Results The control group decreased significantly more than the intervention group on BMI-SDS (β = 0.074, 95%CI: 0.008;0.14), and sum of skinfolds (β = 3.22, 95%CI: 0.27;6.17) (overall effects). The intervention group had a significantly higher decrease in self-reported non-active video game time (β = -1.76, 95%CI: -3.20;-0.32) and total sedentary screen time (Exp (β = 0.81, 95%CI: 0.74;0.88) than the control group (overall effects). The process evaluation showed that 14% of the adolescents played the Move video games every week ≥1 hour/week during the whole intervention period. Conclusions The active video game intervention did not result in lower values on anthropometrics in a group of ‘excessive’ non-active video gamers (mean ~ 14 hours/week) who primarily were of healthy weight compared to a control group throughout a ten-month-period. Even some effects in the unexpected direction were found, with the control group showing lower BMI

  12. Iron stimulates plasma-activated medium-induced A549 cell injury

    PubMed Central

    Adachi, Tetsuo; Nonomura, Saho; Horiba, Minori; Hirayama, Tasuku; Kamiya, Tetsuro; Nagasawa, Hideko; Hara, Hirokazu

    2016-01-01

    Non-thermal atmospheric pressure plasma is applicable to living cells and has emerged as a novel technology for cancer therapy. Plasma has recently been shown to affect cells not only by direct irradiation, but also by indirect treatments with previously prepared plasma-activated medium (PAM). Iron is an indispensable element but is also potentially toxic because it generates the hydroxyl radical (•OH) in the presence of hydrogen peroxide (H2O2) via the Fenton reaction. The aim of the present study was to demonstrate the contribution of iron to PAM-induced A549 adenocarcinoma cell apoptosis. We detected the generation of •OH and elevation of intracellular ferrous ions in PAM-treated cells and found that they were inhibited by iron chelator. The elevations observed in ferrous ions may have been due to their release from the intracellular iron store, ferritin. Hydroxyl radical-induced DNA injury was followed by the activation of poly(ADP-ribose) polymerase-1, depletion of NAD+ and ATP, and elevations in intracellular Ca2+. The sensitivities of normal cells such as smooth muscle cells and keratinocytes to PAM were less than that of A549 cells. These results demonstrated that H2O2 in PAM and/or •OH generated in the presence of iron ions disturbed the mitochondrial-nuclear network in cancer cells. PMID:26865334

  13. Calculation of a mirror asymmetric effect in electron scattering from chiral targets. [in optically active medium

    NASA Technical Reports Server (NTRS)

    Rich, A.; Van House, J.; Hegstrom, R. A.

    1982-01-01

    A dynamical calculation is presented of the helicity induced in an initially unpolarized electron beam after elastic scattering from an optically active medium, a process analogous to the circular polarization induced in unpolarized light following Rayleigh scattering from chiral targets. The calculation is based on the bound helical electron model of a chiral molecule, according to which the major contribution to the helicity is provided by the perturbation of the electron bound state by the spin-orbit interaction of the bound electrons moving in the electric field of the molecular core. The net helicity acquired is found to depend directly on a molecular asymmetry factor and the square of the atomic number of the heaviest atom in an asymmetric environment. For the case of carbon, the induced helicity is on the order of 0.00001, which would account for its lack of observation in a recent experiment. Results may have implications for the origin of optical activity in biological molecules by the differential ionization of D and L isomers by beta-decay electrons.

  14. Iron stimulates plasma-activated medium-induced A549 cell injury.

    PubMed

    Adachi, Tetsuo; Nonomura, Saho; Horiba, Minori; Hirayama, Tasuku; Kamiya, Tetsuro; Nagasawa, Hideko; Hara, Hirokazu

    2016-01-01

    Non-thermal atmospheric pressure plasma is applicable to living cells and has emerged as a novel technology for cancer therapy. Plasma has recently been shown to affect cells not only by direct irradiation, but also by indirect treatments with previously prepared plasma-activated medium (PAM). Iron is an indispensable element but is also potentially toxic because it generates the hydroxyl radical (•OH) in the presence of hydrogen peroxide (H2O2) via the Fenton reaction. The aim of the present study was to demonstrate the contribution of iron to PAM-induced A549 adenocarcinoma cell apoptosis. We detected the generation of •OH and elevation of intracellular ferrous ions in PAM-treated cells and found that they were inhibited by iron chelator. The elevations observed in ferrous ions may have been due to their release from the intracellular iron store, ferritin. Hydroxyl radical-induced DNA injury was followed by the activation of poly(ADP-ribose) polymerase-1, depletion of NAD(+) and ATP, and elevations in intracellular Ca(2+). The sensitivities of normal cells such as smooth muscle cells and keratinocytes to PAM were less than that of A549 cells. These results demonstrated that H2O2 in PAM and/or •OH generated in the presence of iron ions disturbed the mitochondrial-nuclear network in cancer cells. PMID:26865334

  15. Weight gain and inflammation regulate aromatase expression in male adipose tissue, as evidenced by reporter gene activity.

    PubMed

    Polari, L; Yatkin, E; Martínez Chacón, M G; Ahotupa, M; Smeds, A; Strauss, L; Zhang, F; Poutanen, M; Saarinen, N; Mäkelä, S I

    2015-09-01

    Obesity and white adipose tissue (WAT) inflammation are associated with enhanced aromatization in women, but little is known about the regulation of aromatase (CYP19A1) gene expression in male WAT. We investigated the impact of weight gain and WAT inflammation on the regulation of CYP19A1 in males, by utilizing the hARO-Luc aromatase reporter mouse model containing a >100-kb 5'-region of the human CYP19A1 gene. We show that hARO-Luc reporter activity is enhanced in WAT of mice with increased adiposity and inflammation. Dexamethasone and TNFα, as well as forskolin and phorbol 12-myristate 13-acetate, upregulate hARO-Luc activity, suggesting the involvement of promoters I.4 and I.3/II. Furthermore, we show that diet enriched with antioxidative plant polyphenols attenuates WAT inflammation and hARO-Luc activity in obese males. In conclusion, our data suggest that obesity-associated WAT inflammation leads to increased peripheral CYP19A1 expression in males, and that polyphenol-enriched diet may have the potential to attenuate excessive aromatization in WAT of obese men. PMID:26054748

  16. EFFECT OF LASER LIGHT ON MATTER. LASER PLASMAS: Distributed extraction of amplified spontaneous emission from a randomly inhomogeneous active medium

    NASA Astrophysics Data System (ADS)

    Starikov, F. A.

    1993-05-01

    This paper investigates the dynamics of amplified spontaneous x-ray emission escaping from a randomly inhomogeneous plasma active medium through its ends and lateral surface. It is shown that the scattering of radiation by fluctuations in the dielectric permittivity, ɛ˜, can be utilized to extract energy through the lateral surface of the active medium. The radiant intensity is maximal in an off-axis direction in this case. When both regular refraction and scattering by ɛ˜ are operating, the distributed extraction of the light is determined by that effect which has the smaller characteristic length (i.e., the scattering length or the refraction length).

  17. The Relationship of Objectively Measured Physical Activity and Sedentary Behaviour with Gestational Weight Gain and Birth Weight

    PubMed Central

    Ruifrok, Anneloes E.; Althuizen, Ellen; Oostdam, Nicolette; van Mechelen, Willem; de Groot, Christianne J. M.; van Poppel, Mireille N. M.

    2014-01-01

    Objective. To evaluate the relationship of physical activity (PA) and sedentary behaviour with gestational weight gain (GWG) and birth weight. Design. Combined data from two prospective studies: (1) nulliparous pregnant women without BMI restrictions and (2) overweight and obese pregnant women at risk for gestational diabetes. Methods. Daily PA and sedentary behaviour were measured with an accelerometer around 15 and at 32–35 weeks of gestation. The association between time spent in moderate-to-vigorous PA (MVPA) and in sedentary activities with GWG and birth weight was determined. Main outcome measures were GWG between 15 and 32 weeks of gestation, average GWG per week, and birth weight. Results. We studied 111 women. Early in pregnancy, 32% of women spent ≥30 minutes/day in at least moderate PA versus 12% in late pregnancy. No significant associations were found between time spent in MVPA or sedentary behaviour with GWG or birth weight. Conclusions. We found no relation between MVPA and sedentary behaviour with GWG or birth weight. The small percentage of women meeting the recommended levels of PA indicates the need to inform and support pregnant women to maintain regular PA, as there seems to be no adverse effect on birth weight and maintaining PA increases overall health. PMID:25309754

  18. Actively phase-controlled coupling between plasmonic waveguides via in-between gain-assisted nanoresonator: nanoscale optical logic gates.

    PubMed

    Ho, Kum-Song; Han, Yong-Ha; Ri, Chol-Song; Im, Song-Jin

    2016-08-15

    The development of nanoscale optical logic gates has attracted immense attention due to increasing demand for ultrahigh-speed and energy-efficient optical computing and data processing, however, suffers from the difficulty in precise control of phase difference of the two optical signals. We propose a novel conception of nanoscale optical logic gates based on actively phase-controlled coupling between two plasmonic waveguides via an in-between gain-assisted nanoresonator. Precise control of phase difference between the two plasmonic signals can be performed by manipulating pumping rate at an appropriate frequency detuning, enabling a high contrast between the output logic states "1" and "0." Without modification of the structural parameters, different logic functions can be provided. This active nanoscale optical logic device is expected to be quite energy-efficient with ideally low energy consumption on the order of 0.1 fJ/bit. Analytical calculations and numerical experiments demonstrate the validity of the proposed concept. PMID:27519077

  19. Unequal prognostic potentials of p53 gain-of-function mutations in human cancers associate with drug-metabolizing activity.

    PubMed

    Xu, J; Wang, J; Hu, Y; Qian, J; Xu, B; Chen, H; Zou, W; Fang, J-Y

    2014-01-01

    Mutation of p53 is the most common genetic change in human cancer, causing complex effects including not only loss of wild-type function but also gain of novel oncogenic functions (GOF). It is increasingly likely that p53-hotspot mutations may confer different types and magnitudes of GOF, but the evidences are mainly supported by cellular and transgenic animal models. Here we combine large-scale cancer genomic data to characterize the prognostic significance of different p53 mutations in human cancers. Unexpectedly, only mutations on the Arg248 and Arg282 positions displayed significant association with shorter patient survival, but such association was not evident for other hotspot GOF mutations. Gene set enrichment analysis on these mutations revealed higher activity of drug-metabolizing enzymes, including the CYP3A4 cytochrome P450. Ectopic expression of p53 mutant R282W in H1299 and SaOS2 cells significantly upregulated CYP3A4 mRNA and protein levels, and cancer cell lines bearing mortality-associated p53 mutations display higher CYP3A4 expression and resistance to several CYP3A4-metabolized chemotherapeutic drugs. Our results suggest that p53 mutations have unequal GOF activities in human cancers, and future evaluation of p53 as a cancer biomarker should consider which mutation is present in the tumor, rather than having comparison between wild-type and mutant genotypes. PMID:24603336

  20. Ethanol Disinhibits Dorsolateral Striatal Medium Spiny Neurons Through Activation of A Presynaptic Delta Opioid Receptor.

    PubMed

    Patton, Mary H; Roberts, Bradley M; Lovinger, David M; Mathur, Brian N

    2016-06-01

    The dorsolateral striatum mediates habit formation, which is expedited by exposure to alcohol. Across species, alcohol exposure disinhibits the DLS by dampening GABAergic transmission onto this structure's principal medium spiny projection neurons (MSNs), providing a potential mechanistic basis for habitual alcohol drinking. However, the molecular and circuit components underlying this disinhibition remain unknown. To examine this, we used a combination of whole-cell patch-clamp recordings and optogenetics to demonstrate that ethanol potently depresses both MSN- and fast-spiking interneuron (FSI)-MSN GABAergic synaptic transmission in the DLS. Concentrating on the powerfully inhibitory FSI-MSN synapse, we further show that acute exposure of ethanol (50 mM) to striatal slices activates delta opioid receptors that reside on FSI axon terminals and negatively couple to adenylyl cyclase to induce a long-term depression of GABA release onto both direct and indirect pathway MSNs. These findings elucidate a mechanism through which ethanol may globally disinhibit the DLS. PMID:26758662

  1. Active site dynamics in the zinc-dependent medium chain alcohol dehydrogenase superfamily

    PubMed Central

    Baker, Patrick J.; Britton, K. Linda; Fisher, Martin; Esclapez, Julia; Pire, Carmen; Bonete, Maria Jose; Ferrer, Juan; Rice, David W.

    2009-01-01

    Despite being the subject of intensive investigations, many aspects of the mechanism of the zinc-dependent medium chain alcohol dehydrogenase (MDR) superfamily remain contentious. We have determined the high-resolution structures of a series of binary and ternary complexes of glucose dehydrogenase, an MDR enzyme from Haloferax mediterranei. In stark contrast to the textbook MDR mechanism in which the zinc ion is proposed to remain stationary and attached to a common set of protein ligands, analysis of these structures reveals that in each complex, there are dramatic differences in the nature of the zinc ligation. These changes arise as a direct consequence of linked movements of the zinc ion, a zinc-bound bound water molecule, and the substrate during progression through the reaction. These results provide evidence for the molecular basis of proton traffic during catalysis, a structural explanation for pentacoordinate zinc ion intermediates, a unifying view for the observed patterns of metal ligation in the MDR family, and highlight the importance of dynamic fluctuations at the metal center in changing the electrostatic potential in the active site, thereby influencing the proton traffic and hydride transfer events. PMID:19131516

  2. Superconducting quantum metamaterials as an active lasing medium: Effects of disorder

    NASA Astrophysics Data System (ADS)

    Koppenhöfer, Martin; Marthaler, Michael; Schön, Gerd

    2016-06-01

    A metamaterial formed by superconducting circuits or quantum dots can serve as an active lasing medium when coupled to a microwave resonator. For these artificial atoms, in contrast to real atoms, variations in their parameters cannot be avoided. In this paper, we examine the influence of disorder on such a multiatom lasing setup. We find that the lasing process evolves into a self-organized stationary state that is quite robust against disorder. The reason is that photons created by those atoms which are in or close to resonance with the resonator stimulate the emission also of more detuned atoms. Not only the number of photons grows with the number of atoms but also the width of the resonance as a function of the detuning. Similar properties are found for other types of disorder such as variations in the individual coupling. We present relations on how the allowed disorder scales with the number of atoms and confirm it by a numerical analysis. We also provide estimates for the sample-to-sample variations to be expected for setups with moderate numbers of atoms.

  3. PicoGreen dye as an active medium for plastic lasers

    NASA Astrophysics Data System (ADS)

    Pradeep, C.; Vallabhan, C. P. G.; Radhakrishnan, P.; Nampoori, V. P. N.

    2015-08-01

    Deoxyribonucleic acid lipid complex thin films are used as a host material for laser dyes. We tested PicoGreen dye, which is commonly used for the quantification of single and double stranded DNA, for its applicability as lasing medium. PicoGreen dye exhibits enhanced fluorescence on intercalation with DNA. This enormous fluorescence emission is amplified in a planar microcavity to achieve yellow lasing. Here the role of DNA is not only a host medium, but also as a fluorescence dequencher. With the obtained results we have ample reasons to propose PicoGreen dye as a lasing medium, which can lead to the development of DNA based bio-lasers.

  4. Medium Chain Fatty Acids Are Selective Peroxisome Proliferator Activated Receptor (PPAR) γ Activators and Pan-PPAR Partial Agonists

    PubMed Central

    Ayers, Steven D.; Lin, Jean Z.; Cvoro, Aleksandra; Silveira, Rodrigo L.; Martínez, Leandro; Souza, Paulo C. T.; Saidemberg, Daniel; Deng, Tuo; Amato, Angela Angelica; Togashi, Marie; Hsueh, Willa A.; Phillips, Kevin; Palma, Mário Sérgio; Neves, Francisco A. R.; Skaf, Munir S.; Webb, Paul; Polikarpov, Igor

    2012-01-01

    Thiazolidinediones (TZDs) act through peroxisome proliferator activated receptor (PPAR) γ to increase insulin sensitivity in type 2 diabetes (T2DM), but deleterious effects of these ligands mean that selective modulators with improved clinical profiles are needed. We obtained a crystal structure of PPARγ ligand binding domain (LBD) and found that the ligand binding pocket (LBP) is occupied by bacterial medium chain fatty acids (MCFAs). We verified that MCFAs (C8–C10) bind the PPARγ LBD in vitro and showed that they are low-potency partial agonists that display assay-specific actions relative to TZDs; they act as very weak partial agonists in transfections with PPARγ LBD, stronger partial agonists with full length PPARγ and exhibit full blockade of PPARγ phosphorylation by cyclin-dependent kinase 5 (cdk5), linked to reversal of adipose tissue insulin resistance. MCFAs that bind PPARγ also antagonize TZD-dependent adipogenesis in vitro. X-ray structure B-factor analysis and molecular dynamics (MD) simulations suggest that MCFAs weakly stabilize C-terminal activation helix (H) 12 relative to TZDs and this effect is highly dependent on chain length. By contrast, MCFAs preferentially stabilize the H2-H3/β-sheet region and the helix (H) 11-H12 loop relative to TZDs and we propose that MCFA assay-specific actions are linked to their unique binding mode and suggest that it may be possible to identify selective PPARγ modulators with useful clinical profiles among natural products. PMID:22649490

  5. Allele-specific silencing of mutant p53 attenuates dominant-negative and gain-of-function activities

    PubMed Central

    Iyer, Swathi V.; Parrales, Alejandro; Begani, Priya; Narkar, Akshay; Adhikari, Amit S.; Martinez, Luis A.; Iwakuma, Tomoo

    2016-01-01

    Many p53 hotspot mutants not only lose the transcriptional activity, but also show dominant-negative (DN) and oncogenic gain-of-function (GOF) activities. Increasing evidence indicates that knockdown of mutant p53 (mutp53) in cancer cells reduces their aggressive properties, suggesting that survival and proliferation of cancer cells are, at least partially, dependent on the presence of mutp53. However, these p53 siRNAs can downregulate both wild-type p53 (wtp53) and mutp53, which limits their therapeutic applications. In order to specifically deplete mutp53, we have developed allele-specific siRNAs against p53 hotspot mutants and validated their biological effects in the absence or presence of wtp53. First, the mutp53-specific siRNAs selectively reduced protein levels of matched p53 mutants with minimal reduction in wtp53 levels. Second, downregulation of mutp53 in cancer cells expressing a mutp53 alone (p53mut) resulted in significantly decreased cell proliferation and migration. Third, transfection of mutp53-specific siRNAs in cancer cells expressing both wtp53 and mutp53 also reduced cell proliferation and migration with increased transcripts of p53 downstream target genes, which became further profound when cells were treated with an MDM2 inhibitor Nutlin-3a or a chemotherapeutic agent doxorubicin. These results indicate that depletion of mutp53 by its specific siRNA restored endogenous wtp53 activity in cells expressing both wtp53 and mutp53. This is the first study demonstrating biological effects and therapeutic potential of allele-specific silencing of mutp53 by mutp53-specific siRNAs in cancer cells expressing both wtp53 and mutp53, thus providing a novel strategy towards targeted cancer therapies. PMID:26700961

  6. Indirect flat-panel detector with avalanche gain: Fundamental feasibility investigation for SHARP-AMFPI (scintillator HARP active matrix flat panel imager)

    SciTech Connect

    Zhao Wei; Li Dan; Reznik, Alla; Lui, B.J.M.; Hunt, D.C.; Rowlands, J.A.; Ohkawa, Yuji; Tanioka, Kenkichi

    2005-09-15

    An indirect flat-panel imager (FPI) with avalanche gain is being investigated for low-dose x-ray imaging. It is made by optically coupling a structured x-ray scintillator CsI(Tl) to an amorphous selenium (a-Se) avalanche photoconductor called HARP (high-gain avalanche rushing photoconductor). The final electronic image is read out using an active matrix array of thin film transistors (TFT). We call the proposed detector SHARP-AMFPI (scintillator HARP active matrix flat panel imager). The advantage of the SHARP-AMFPI is its programmable gain, which can be turned on during low dose fluoroscopy to overcome electronic noise, and turned off during high dose radiography to avoid pixel saturation. The purpose of this paper is to investigate the important design considerations for SHARP-AMFPI such as avalanche gain, which depends on both the thickness d{sub Se} and the applied electric field E{sub Se} of the HARP layer. To determine the optimal design parameter and operational conditions for HARP, we measured the E{sub Se} dependence of both avalanche gain and optical quantum efficiency of an 8 {mu}m HARP layer. The results were used in a physical model of HARP as well as a linear cascaded model of the FPI to determine the following x-ray imaging properties in both the avalanche and nonavalanche modes as a function of E{sub Se}: (1) total gain (which is the product of avalanche gain and optical quantum efficiency); (2) linearity; (3) dynamic range; (4) gain nonuniformity resulting from thickness nonuniformity; and (5) effects of direct x-ray interaction in HARP. Our results showed that a HARP layer thickness of 8 {mu}m can provide adequate avalanche gain and sufficient dynamic range for x-ray imaging applications to permit quantum limited operation over the range of exposures needed for radiography and fluoroscopy.

  7. Indirect flat-panel detector with avalanche gain: fundamental feasibility investigation for SHARP-AMFPI (scintillator HARP active matrix flat panel imager).

    PubMed

    Zhao, Wei; Li, Dan; Reznik, Alla; Lui, B J M; Hunt, D C; Rowlands, J A; Ohkawa, Yuji; Tanioka, Kenkichi

    2005-09-01

    An indirect flat-panel imager (FPI) with avalanche gain is being investigated for low-dose x-ray imaging. It is made by optically coupling a structured x-ray scintillator CsI(Tl) to an amorphous selenium (a-Se) avalanche photoconductor called HARP (high-gain avalanche rushing photoconductor). The final electronic image is read out using an active matrix array of thin film transistors (TFT). We call the proposed detector SHARP-AMFPI (scintillator HARP active matrix flat panel imager). The advantage of the SHARP-AMFPI is its programmable gain, which can be turned on during low dose fluoroscopy to overcome electronic noise, and turned off during high dose radiography to avoid pixel saturation. The purpose of this paper is to investigate the important design considerations for SHARP-AMFPI such as avalanche gain, which depends on both the thickness d(Se) and the applied electric field E(Se) of the HARP layer. To determine the optimal design parameter and operational conditions for HARP, we measured the E(Se) dependence of both avalanche gain and optical quantum efficiency of an 8 microm HARP layer. The results were used in a physical model of HARP as well as a linear cascaded model of the FPI to determine the following x-ray imaging properties in both the avalanche and nonavalanche modes as a function of E(Se): (1) total gain (which is the product of avalanche gain and optical quantum efficiency); (2) linearity; (3) dynamic range; (4) gain nonuniformity resulting from thickness nonuniformity; and (5) effects of direct x-ray interaction in HARP. Our results showed that a HARP layer thickness of 8 microm can provide adequate avalanche gain and sufficient dynamic range for x-ray imaging applications to permit quantum limited operation over the range of exposures needed for radiography and fluoroscopy. PMID:16266110

  8. Singularity of influence of stochastic and order phase structures on optical quality of gas-dynamic laser active medium flow

    NASA Astrophysics Data System (ADS)

    Kovalevsky, Valery O.; Lobachev, Vitaly V.

    2002-02-01

    Detail analysis of active medium flow structure is presented. Schlieren method photography of flow is processed to reconstruct parameters both stochastic and order phase components. Properties of random part including correlation function, spectrum of spatial frequency, scale of turbulence, are determined by digital filtering. It was possible to compare influence of random and regular phase distortions on radiation divergence structure.

  9. Gain-enhanced optical cooling in cavity optomechanics

    NASA Astrophysics Data System (ADS)

    Ge, Li; Faez, Sanli; Marquardt, Florian; Tureci, Hakan

    2013-03-01

    We study the optical cooling of the mechanical motion of the resonator mirror in a cavity-optomechanical system that contains an optical gain medium. We find that the optical damping caused by radiation pressure force is vanishingly small if the active medium is pumped incoherently above its lasing threshold. In addition, we find that the spontaneous emission of the active medium always tends to increase the final effective temperature of the mechanical motion. In the presence of an additional seeding signal, i.e. a coherent drive of fixed frequency within the width of the gain curve however, we find that the cooling rate can be enhanced significantly with respect to that of a passive cavity. We attribute this effect to a reduced effective optical damping in the presence of incoherent pumping.

  10. Does Structured Quizzing with Process Specific Feedback Lead to Learning Gains in an Active Learning Geoscience Classroom?

    NASA Astrophysics Data System (ADS)

    Palsole, S.; Serpa, L. F.

    2013-12-01

    There is a great realization that efficient teaching in the geosciences has the potential to have far reaching effects in outreach to decision and policy makers (Herbert, 2006; Manduca & Mogk, 2006). This research in turn informs educators that the geosciences by the virtue of their highly integrative nature play an important role in serving as an entry point into STEM disciplines and helping developing a new cadre of geoscientists, scientists and a general population with an understanding of science. Keeping these goals in mind we set to design introductory geoscience courses for non-majors and majors that move away from the traditional lecture models which don't necessarily contribute well to knowledge building and retention ((Handelsman et al., 2007; Hake, 1997) to a blended active learning classroom where basic concepts and didactic information is acquired online via webquests, lecturettes and virtual field trips and the face to face portions of the class are focused on problem solving exercises. The traditional way to ensure that students are prepared for the in-class activity is to have the students take a quiz online to demonstrate basic competency. In the process of redesign, we decided to leverage the technology to build quizzes that are highly structured and map to a process (formation of divergent boundaries for example) or sets of earth processes that we needed the students to know before in-class activities. The quizzes can be taken multiple times and provide process specific feedback, thus serving as a heuristic to the students to ensure they have acquired the necessary competency. The heuristic quizzes were developed and deployed over a year with the student data driving the redesign process to ensure synchronicity. Preliminary data analysis indicates a positive correlation between higher student scores on in-class application exercises and time spent on the process quizzes. An assessment of learning gains also indicate a higher degree of self

  11. A Newly Identified CG301269 Improves Lipid and Glucose Metabolism Without Body Weight Gain Through Activation of Peroxisome Proliferator–Activated Receptor α and γ

    PubMed Central

    Jeong, Hyun Woo; Lee, Joo-Won; Kim, Woo Sik; Choe, Sung Sik; Kim, Kyung-Hee; Park, Ho Seon; Shin, Hyun Jung; Lee, Gha Young; Shin, Dongkyu; Lee, Hanjae; Lee, Jun Hee; Choi, Eun Bok; Lee, Hyeon Kyu; Chung, Heekyoung; Park, Seung Bum; Park, Kyong Soo; Kim, Hyo-Soo; Ro, Seonggu; Kim, Jae Bum

    2011-01-01

    OBJECTIVE Peroxisome proliferator–activated receptor (PPAR)-α/γ dual agonists have been developed to alleviate metabolic disorders. However, several PPARα/γ dual agonists are accompanied with unwanted side effects, including body weight gain, edema, and tissue failure. This study investigated the effects of a novel PPARα/γ dual agonist, CG301269, on metabolic disorders both in vitro and in vivo. RESEARCH DESIGN AND METHODS Function of CG301269 as a PPARα/γ dual agonist was assessed in vitro by luciferase reporter assay, mammalian one-hybrid assay, and analyses of PPAR target genes. In vitro profiles on fatty acid oxidation and inflammatory responses were acquired by fatty acid oxidation assay and quantitative (q)RT-PCR of proinflammatory genes. In vivo effect of CG301269 was examined in db/db mice. Total body weight and various tissue weights were measured, and hepatic lipid profiles were analyzed. Systemic glucose and insulin tolerance were measured, and the in vivo effect of CG301269 on metabolic genes and proinflammatory genes was examined by qRT-PCR. RESULTS CG301269 selectively stimulated the transcriptional activities of PPARα and PPARγ. CG301269 enhanced fatty acid oxidation in vitro and ameliorated insulin resistance and hyperlipidemia in vivo. In db/db mice, CG301269 reduced inflammatory responses and fatty liver, without body weight gain. CONCLUSIONS We demonstrate that CG301269 exhibits beneficial effects on glucose and lipid metabolism by simultaneous activation of both PPARα and PPARγ. Our data suggest that CG301269 would be a potential lead compound against obesity and related metabolic disorders. PMID:21270261

  12. Effect of vibrationally excited I{sub 2}(a{sup 1{Delta}}{sub g}) molecules on the parameters of the active medium of an oxygen - iodine laser

    SciTech Connect

    Azyazov, V N; Antonov, I O; Pichugin, S Yu; Ufimtsev, N I

    2004-12-31

    A comparison of the experimental and theoretical results shows that quenching of one singlet oxygen molecule leads to the formation of 4.5 vibrational quanta of the I{sub 2} molecule on the average in the active medium of an oxygen-iodine laser. The dependence of threshold yield of singlet oxygen and of the gain on the relative concentration of vibrationally excited I{sub 2}(a{sup 1{Delta}}{sub g}) molecules are studied. The threshold yield of singlet oxygen increases with the relative concentration of vibrationally excited I{sub 2} molecules and may be several percent higher than the value assumed earlier. The gain depends weakly on the relative concentration of vibrationally excited oxygen molecules. (active media)

  13. Effects of novel auto-inducible medium on growth, activity and CO₂ capture capacity of Escherichia coli expressing carbonic anhydrase.

    PubMed

    Watson, Stuart K; Kan, Eunsung

    2015-10-01

    A glucose-based auto-inducible medium (glucose-AIM) has been developed to enhance both growth and expression of lac operon-linked carbonic anhydrase (CA) expression in a recombinant strain of Escherichia coli. When the E. coli expressing CA was grown on various media, the glucose-based auto-inducible medium (glucose AIM) resulted in a CA activity of 1022 mU OD(600 nm)(-1) mL(-1) at 24 h and a specific growth rate of 0.082 h(-1). The CA activity was four to fourteen times higher than those by LB-IPTG. The E. coli expressing CA grown on the glucose-AIM showed highest activity at pH8.5 while it kept high stability up to 40°C and an inlet CO2 concentration of 6%. These findings indicate that the glucose-AIM would be a cost-effective medium to support high cell growth, CA activity and stability for effective CO2 capture. PMID:26264623

  14. Clearing-factor lipase in adipose tissue. A medium in which the enzyme activity of tissue from starved rats increases in vitro

    PubMed Central

    Salaman, M. R.; Robinson, D. S.

    1966-01-01

    1. When epididymal fat bodies from starved rats are incubated for 3·5hr. at 37° in a defined medium in vitro the total clearing-factor lipase activity rises to approximately twice its initial value. 2. During the incubation period part of the tissue clearing-factor lipase activity appears in the medium. 3. Heparin, glucose, insulin, and HCO3− and K+ ions are shown to be important medium constituents. PMID:5964961

  15. Second malignancies in patients with differentiated thyroid carcinoma treated with low and medium activities of radioactive I-131

    PubMed Central

    PICIU, DOINA; PESTEAN, CLAUDIU; BARBUS, ELENA; LARG, MARIA IULIA; PICIU, ANDRA

    2016-01-01

    Background and aim This study aimed at determining whether there is a risk regarding the development of second primary malignancies after patient exposure to the low and medium radioiodine activity used during the treatment of differentiated thyroid cancers (DTC). Methods Second primary malignancies that occurred after DTC were detected in 1,990 patients treated between 1970 and 2003. The mean long-term follow-up period was 182 months. Results Radioiodine I-131was administrated at a mean dose of 63.2 mCi. There were 93 patients with at least one second primary malignancy. The relative risk of development of second malignancy in DTC patients was increased (p<0.0001) for breast, uterine and ovarian cancers compared with the general population. Conclusions The overall risk concerning the development of second primary malignancies was related to the presence of DTC, but not to exposure to the low and medium activities of radioiodine administered as adjuvant therapy. PMID:27547058

  16. Net Gains

    ERIC Educational Resources Information Center

    Fielker, David

    2008-01-01

    The Easter conference 2008 had several activities which for the author raised the same questions on cube nets in some work with eight-year-olds some time ago. In this article, the author muses on some problems from the Easter conference regarding nets of shapes. (Contains 1 note.)

  17. The effects of X-rays from active galactic nuclei on the interstellar medium of the surrounding galaxy

    NASA Technical Reports Server (NTRS)

    Begelman, Mitchell C.

    1988-01-01

    The effects of an active nucleus on the large-scale properties of the host galaxy are examined, focusing on the effects of X-ray heating on the host galaxy's interstellar medium. The basic properties of AGNs and several questions concerning AGNs are reviewed. The relationship between X-ray heated winds and coronae is outlined. The case of X-ray heated winds in type 2 Seyfert galaxies is discussed.

  18. Pregnancy Weight Gain Calculator

    MedlinePlus

    ... Newsroom Dietary Guidelines Communicator’s Guide Pregnancy Weight Gain Calculator You are here Home / Online Tools Pregnancy Weight Gain Calculator Print Share Pregnancy Weight Gain Calculator Pregnancy Weight Gain Calculator Pregnancy Weight Gain Intro ...

  19. Gain of function AMP-activated protein kinase γ3 mutation (AMPKγ3R200Q) in pig muscle increases glycogen storage regardless of AMPK activation.

    PubMed

    Scheffler, Tracy L; Park, Sungkwon; Roach, Peter J; Gerrard, David E

    2016-06-01

    Chronic activation of AMP-activated protein kinase (AMPK) increases glycogen content in skeletal muscle. Previously, we demonstrated that a mutation in the ryanodine receptor (RyR1(R615C)) blunts AMPK phosphorylation in longissimus muscle of pigs with a gain of function mutation in the AMPKγ3 subunit (AMPKγ3(R200Q)); this may decrease the glycogen storage capacity of AMPKγ3(R200Q) + RyR1(R615C) muscle. Therefore, our aim in this study was to utilize our pig model to understand how AMPKγ3(R200Q) and AMPK activation contribute to glycogen storage and metabolism in muscle. We selected and bred pigs in order to generate offspring with naturally occurring AMPKγ3(R200Q), RyR1(R615C), and AMPKγ3(R200Q) + RyR1(R615C) mutations, and also retained wild-type littermates (control). We assessed glycogen content and parameters of glycogen metabolism in longissimus muscle. Regardless of RyR1(R615C), AMPKγ3(R200Q) increased the glycogen content by approximately 70%. Activity of glycogen synthase (GS) without the allosteric activator glucose 6-phosphate (G6P) was decreased in AMPKγ3(R200Q) relative to all other genotypes, whereas both AMPKγ3(R200Q) and AMPKγ3(R200Q) + RyR1(R615C) muscle exhibited increased GS activity with G6P. Increased activity of GS with G6P was not associated with increased abundance of GS or hexokinase 2. However, AMPKγ3(R200Q) enhanced UDP-glucose pyrophosphorylase 2 (UGP2) expression approximately threefold. Although UGP2 is not generally considered a rate-limiting enzyme for glycogen synthesis, our model suggests that UGP2 plays an important role in increasing flux to glycogen synthase. Moreover, we have shown that the capacity for glycogen storage is more closely related to the AMPKγ3(R200Q) mutation than activity. PMID:27302990

  20. Synthesis, antimicrobial activity and molecular docking of novel tetracyclic scaffolds incorporating a flavonoid framework with medium sized oxygen heterocycles.

    PubMed

    Dongamanti, Ashok; Aamate, Vikas Kumar; Devulapally, Mohan Gandhi; Gundu, Srinivas; Kotni, Meena Kumari; Manga, Vijjulatha; Balasubramanian, Sridhar; Ernala, Prasad

    2015-02-15

    A convenient approach for the synthesis of novel tetracyclic scaffolds incorporating a flavonoid framework with medium sized heterocyclic rings (eight-, nine-, ten- and eleven-membered rings) containing two oxygen atoms from flavonols through alkylation using different dibromoalkanes was described. The synthesized compounds were established based on the spectral data and X-ray crystal structure for 6c. The synthesized compounds were evaluated for their in vitro antimicrobial activity. Docking studies were carried out for most active two compounds 6f and 6i. PMID:25592711

  1. Agroecosystem development of industrial fermentation waste -- characterization of aroma-active compounds from the cultivation medium of Lactobacillus brevis.

    PubMed

    Ono, Toshirou; Usami, Atsushi; Nakaya, Satoshi; Shinpuku, Hideto; Yonejima, Yasunori; Ikeda, Atsushi; Miyazawa, Mitsuo

    2015-01-01

    Volatile oils obtained from both the liquid medium after incubation (MAI) and liquid medium before incubation (MBI) during the cultivation process of Lactobacillus brevis were isolated by hydrodistillation (HD) and analyzed to determine the utility of the liquid waste. The composition of the volatile oils was analyzed by capillary gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). In total, 55 and 36 compounds were detected in the volatile oils from MAI (MAI oil) and MBI (MBI oil), respectively. The principle components of MAI oil were N-containing compounds, including 2,3-dimethylpyrazine (16, 37.1 %), methylpyrazine (4, 17.1 %). The important aroma-active compounds in the oils were detected by GC-Olfactometry (GC-O), and their intensity of aroma were measured by aroma extract dilution analysis (AEDA). Expressly, pyrazine compounds were determined as key aroma components; in particular, 2,5-dimethylpyrazine and 2,3-dimethylpyrazine were the most primary aroma-active compound in MAI oil. These results imply that the waste medium after incubation of L. brevis may be utilized as a source of volatile oils. PMID:25843282

  2. Creating a flipbook as a medium of instruction based on the research on activity test of kencur extract

    NASA Astrophysics Data System (ADS)

    Monika, Icha; Yeni, Laili Fitri; Ariyati, Eka

    2016-02-01

    This research aimed to reveal the validity of the flipbook as a medium of learning for the sub-material of environmental pollution in the tenth grade based on the results of the activity test of kencur (Kaempferia galanga) extract to control the growth of the Fusarium oxysporum fungus. The research consisted of two stages. First, testing the validity of the medium of flipbook through validation by seven assessors and analyzed based on the total average score of all aspects. Second, testing the activity of the kencur extract against the growth of Fusarium oxysporum by using the experimental method with 10 treatments and 3 repetitions which were analyzed using one-way analysis of variance (ANOVA) test. The making of the flipbook medium was done through the stages of analysis for the potential and problems, data collection, design, validation, and revision. The validation analysis on the flipbook received an average score of 3.7 and was valid to a certain extent, so it could be used in the teaching and learning process especially in the sub-material of environmental pollution in the tenth grade of the senior high school.

  3. Measurements and simulations of the optical gain and anti-reflection coating modal reflectivity in quantum cascade lasers with multiple active region stacks

    NASA Astrophysics Data System (ADS)

    Bidaux, Y.; Terazzi, R.; Bismuto, A.; Gresch, T.; Blaser, S.; Muller, A.; Faist, J.

    2015-09-01

    We report spectrally resolved gain measurements and simulations for quantum cascade lasers (QCLs) composed of multiple heterogeneous stacks designed for broadband emission in the mid-infrared. The measurement method is first demonstrated on a reference single active region QCL based on a double-phonon resonance design emitting at 7.8 μm. It is then extended to a three-stack active region based on bound-to-continuum designs with a broadband emission range from 7.5 to 10.5 μm. A tight agreement is found with simulations based on a density matrix model. The latter implements exhaustive microscopic scattering and dephasing sources with virtually no fitting parameters. The quantitative agreement is furthermore assessed by measuring gain coefficients obtained by studying the threshold current dependence with the cavity length. These results are particularly relevant to understand fundamental gain mechanisms in complex semiconductor heterostructure QCLs and to move towards efficient gain engineering. Finally, the method is extended to the measurement of the modal reflectivity of an anti-reflection coating deposited on the front facet of the broadband QCL.

  4. Activation of the prefrontal cortex by unilateral transcranial direct current stimulation leads to an asymmetrical effect on risk preference in frames of gain and loss.

    PubMed

    Ye, Hang; Huang, Daqiang; Wang, Siqi; Zheng, Haoli; Luo, Jun; Chen, Shu

    2016-10-01

    Previous brain imaging and brain stimulation studies have suggested that the dorsolateral prefrontal cortex may be critical in regulating risk-taking behavior, although its specific causal effect on people's risk preference remains controversial. This paper studied the independent modulation of the activity of the right and left dorsolateral prefrontal cortex using various configurations of transcranial direct current stimulation. We designed a risk-measurement table and adopted a within-subject design to compare the same participant's risk preference before and after unilateral stimulation when presented with different frames of gain and loss. The results confirmed a hemispheric asymmetry and indicated that the right dorsolateral prefrontal cortex has an asymmetric effect on risk preference regarding frames of gain and loss. Enhancing the activity of the right dorsolateral prefrontal cortex significantly decreased the participants' degree of risk aversion in the gain frame, whereas it increased the participants' degree of risk aversion in the loss frame. Our findings provide important information regarding the impact of transcranial direct current stimulation on the risk preference of healthy participants. The effects observed in our experiment compared with those of previous studies provide further evidence of the effects of hemispheric and frame-dependent asymmetry. These findings may be helpful in understanding the neural basis of risk preference in humans, especially when faced with decisions involving possible gain or loss relative to the status quo. PMID:27507423

  5. Measurements and simulations of the optical gain and anti-reflection coating modal reflectivity in quantum cascade lasers with multiple active region stacks

    SciTech Connect

    Bidaux, Y.; Terazzi, R.; Bismuto, A.; Gresch, T.; Blaser, S.; Muller, A.; Faist, J.

    2015-09-07

    We report spectrally resolved gain measurements and simulations for quantum cascade lasers (QCLs) composed of multiple heterogeneous stacks designed for broadband emission in the mid-infrared. The measurement method is first demonstrated on a reference single active region QCL based on a double-phonon resonance design emitting at 7.8 μm. It is then extended to a three-stack active region based on bound-to-continuum designs with a broadband emission range from 7.5 to 10.5 μm. A tight agreement is found with simulations based on a density matrix model. The latter implements exhaustive microscopic scattering and dephasing sources with virtually no fitting parameters. The quantitative agreement is furthermore assessed by measuring gain coefficients obtained by studying the threshold current dependence with the cavity length. These results are particularly relevant to understand fundamental gain mechanisms in complex semiconductor heterostructure QCLs and to move towards efficient gain engineering. Finally, the method is extended to the measurement of the modal reflectivity of an anti-reflection coating deposited on the front facet of the broadband QCL.

  6. BeAl6O10: Cr3+: a promising active medium for femtosecond lasers

    NASA Astrophysics Data System (ADS)

    Petrov, V. V.; Pestryakov, Efim V.; Trunov, V. I.; Kirpichnikov, A. V.; Alimpiev, A. I.

    2003-10-01

    The new laser crystals BeAl6O10:Cr3+ were grown, spectral-luminescence and CW laser properties were investigated and compared with those of well-known laser medium-alexandrite (BeAl2O4:Cr3+). CW laser generation on vibronic transition 4T2-4A2 of Cr3+ ions in BeAl6O10 crystals was realized in the range of 800-880 nm under Ar+ laser pumping. The emission cross-section of laser transition was estimated about 6×10-20 cm2. We confirmed these crystals are perspective for generation of femtosecond pulses in the near IR region under LD pumping.

  7. Thermally activated decomposition of (Ga,Mn)As thin layer at medium temperature post growth annealing

    NASA Astrophysics Data System (ADS)

    Melikhov, Y.; Konstantynov, P.; Domagala, J.; Sadowski, J.; Chernyshova, M.; Wojciechowski, T.; Syryanyy, Y.; Demchenko, I. N.

    2016-05-01

    The redistribution of Mn atoms in Ga1-xMnxAs layer during medium-temperature annealing, 250-450 oC, by Mn K-edge X-ray absorption fine structure (XAFS) recorded at ALBA facility, was studied. For this purpose Ga1-xMnxAs thin layer with x=0.01 was grown on AlAs buffer layer deposited on GaAs(100) substrate by molecular beam epitaxy (MBE) followed by annealing. The examined layer was detached from the substrate using a “lift-off” procedure in order to eliminate elastic scattering in XAFS spectra. Fourier transform analysis of experimentally obtained EXAFS spectra allowed to propose a model which describes a redistribution/diffusion of Mn atoms in the host matrix. Theoretical XANES spectra, simulated using multiple scattering formalism (FEFF code) with the support of density functional theory (WIEN2k code), qualitatively describe the features observed in the experimental fine structure.

  8. Order of Activity of Nitrogen, Iron Oxide, and FeNx Complexes towards Oxygen Reduction in Alkaline Medium.

    PubMed

    Zhu, Yansong; Zhang, Bingsen; Wang, Da-Wei; Su, Dang Sheng

    2015-12-01

    In alkaline medium, it seems that both metal-free and iron-containing carbon-based catalysts, such as nitrogen-doped nanocarbon materials, FeOx -doped carbon, and Fe/N/C catalysts, are active for the oxygen reduction reaction (ORR). However, the order of activity of these different active compositions has not been clearly determined. Herein, we synthesized nitrogen-doped carbon black (NCB), Fe3 O4 /CB, Fe3 O4 /NCB, and FeN4 /CB. Through the systematic study of the ORR catalytic activity of these four catalysts in alkaline solution, we confirmed the difference in the catalytic activity and catalytic mechanism for nitrogen, iron oxides, and Fe-N complexes, respectively. In metal-free NCB, nitrogen can improve the ORR catalytic activity with a four-electron pathway. Fe3 O4 /CB catalyst did not exhibit improved activity over that of NCB owing to the poor conductivity and spinel structure of Fe3 O4 . However, FeN4 coordination compounds as the active sites showed excellent ORR catalytic activity. PMID:26609795

  9. Reduction of methylene green by EDTA: a relation between dielectric constant of medium and activated state.

    PubMed

    Qamar, Noshab; Azmat, Rafia; Naz, Raheela

    2013-01-01

    Kinetics of an alkaline reduction of the methylene green with ethylenediaminetetraaceticacid (EDTA) as a role of dielectric constant of the medium with anecdotal ionic strength in a diverse solvent system (aqueous mixtures of methanol) (10-30%) was studied by measuring the specific rate constant of the reaction spectrophotometrically at λ (max) = 660nm. An effort has been made to give an elucidation of vital role of dielectric constant of the medium captivating into reflection of single sphere and double sphere complex in reaction assortment. This investigation leads to disclose that single sphere complex of the dye and reductant was found to be the most suitable complex existed in a varied organic solvent. The deviation of the theoretical values from experimental results for single sphere and double sphere complex model in the presence of an alkali and nitrate ions were justified through HPLC analysis. HPLC analysis recommended that a considerable amount of the dye degrades in the existence of nitrate ion and alkali and additional peaks which may be of by-product were obtained. This leads to confirm the non identical values of single sphere and double sphere model in the occurrence of nitrate and an alkali. Rate of deletion of color showed a linear liaison with respect to water content below 30% and temperature between 20-40(o)C whereas an increase in the concentration of organic solvent showed the inhibition of dye decoloration at given optimum condition. Therefore study was restricted up to 30% of methanol binary mixtures. A mechanism of reduction of dye has been proposed based on verdict. PMID:23261728

  10. Active video games as a tool to prevent excessive weight gain in adolescents: rationale, design and methods of a randomized controlled trial

    PubMed Central

    2014-01-01

    Background Excessive body weight, low physical activity and excessive sedentary time in youth are major public health concerns. A new generation of video games, the ones that require physical activity to play the games –i.e. active games- may be a promising alternative to traditional non-active games to promote physical activity and reduce sedentary behaviors in youth. The aim of this manuscript is to describe the design of a study evaluating the effects of a family oriented active game intervention, incorporating several motivational elements, on anthropometrics and health behaviors in adolescents. Methods/Design The study is a randomized controlled trial (RCT), with non-active gaming adolescents aged 12 – 16 years old randomly allocated to a ten month intervention (receiving active games, as well as an encouragement to play) or a waiting-list control group (receiving active games after the intervention period). Primary outcomes are adolescents’ measured BMI-SDS (SDS = adjusted for mean standard deviation score), waist circumference-SDS, hip circumference and sum of skinfolds. Secondary outcomes are adolescents’ self-reported time spent playing active and non-active games, other sedentary activities and consumption of sugar-sweetened beverages. In addition, a process evaluation is conducted, assessing the sustainability of the active games, enjoyment, perceived competence, perceived barriers for active game play, game context, injuries from active game play, activity replacement and intention to continue playing the active games. Discussion This is the first adequately powered RCT including normal weight adolescents, evaluating a reasonably long period of provision of and exposure to active games. Next, strong elements are the incorporating motivational elements for active game play and a comprehensive process evaluation. This trial will provide evidence regarding the potential contribution of active games in prevention of excessive weight gain in

  11. Using Medium Resolution Earth Observation Data to Monitor Sensitive Industrial Activities

    NASA Astrophysics Data System (ADS)

    Verstraete, M. M.; Hunt, L. A.; Gonçalves, J.

    2008-12-01

    Space-borne Earth Observation (EO) techniques have been used for decades to monitor climate and environmental processes, but the application of these tools to quantitatively characterize sensitive industrial complexes and especially to monitor safety - or security - related sites is still in its infancy. Photo- interpretation of very high spatial resolution imagery (from 1 to 10 m sampling frequency) for specific, pre- defined sites by specially-trained operators remains the main (or only) approach so far. This paper shows that medium resolution EO sensors (spatial sampling of the order of 250 m) and modern physically-based techniques of data analysis may prove complementary to these traditional techniques, as the radiometric, spatial, temporal, spectral and directional signatures of targets of interest can help characterize their nature, properties and structure, and differentiate them from ambient background. The re-processing of existing archives will be shown to be useful for the documentation of events, and possibly processes, that have remained hitherto unknown. The preliminary results that will be presented concern the construction time-line of an alleged (undeclared) nuclear facility. Comparing the performance of the MISR and MODIS sensors that implement quite different technologies leads to suggestions concerning the specifications of future EO sensors.

  12. Biological activity of a standardized freeze-dried platelet derivative to be used as cell culture medium supplement.

    PubMed

    Muraglia, Anita; Ottonello, Chiara; Spanò, Raffaele; Dozin, Beatrice; Strada, Paolo; Grandizio, Michele; Cancedda, Ranieri; Mastrogiacomo, Maddalena

    2014-01-01

    Serum of animal origin and in particular fetal bovine serum is the most commonly utilized cell culture medium additive for in vitro cell growth and differentiation. However, several major concerns have been raised by the scientific community regarding the use of animal sera for human cell-based culture applications. Among the possible alternatives to the animal serum, platelet-derived compounds have been proposed since more than 10 years. Nevertheless, the high degree of variability between the different platelet preparations, and the lack of standardized manufacturing and quality control procedures, made difficult to reach a consensus on the applicability of this novel cell culture medium supplement. In this study, we describe the preparation of a standardized platelet-rich plasma (PRP) derivative obtained starting from human-certified buffy coat samples with a defined platelet concentration and following protocols including also freeze-drying, gamma irradiation and biological activity testing prior the product release as cell culture medium additive. Biological activity testing of the different preparations was done by determining the capability of the different PRP preparations to sustain human bone marrow mesenchymal stem cell (MSC) clone formation and proliferation. Taking advantage of a developed MSC in vitro clonogenicity test, we also determined biological activity and stability of the freeze-dried gamma-sterilized PRP preparations after their storage for different times and at different temperatures. The PRP effects on cell proliferation were determined both on primary cell cultures established from different tissues and on a cell line. Results were compared with those obtained in "traditional" parallel control cultures performed in the presence of bovine serum [10% fetal calf serum (FCS)]. Compared to FCS, the PRP addition to the culture medium increased the MSC colony number and average size. In primary cell cultures and in cell line cultures, the PRP

  13. Enhancement of β-Glucosidase Activity from a Brown Rot Fungus Fomitopsis pinicola KCTC 6208 by Medium Optimization.

    PubMed

    Park, Ah Reum; Park, Jeong-Hoon; Ahn, Hye-Jin; Jang, Ji Yeon; Yu, Byung Jo; Um, Byung-Hwan; Yoon, Jeong-Jun

    2015-03-01

    β-Glucosidase, which hydrolyzes cellobiose into two glucoses, plays an important role in the process of saccharification of the lignocellulosic biomass. In this study, we optimized the activity of β-glucosidase of brown-rot fungus Fomitopsis pinicola KCTC 6208 using the response surface methodology (RSM) with various concentrations of glucose, yeast extract and ascorbic acid, which are the most significant nutrients for activity of β-glucosidase. The highest activity of β-glucosidase was achieved 3.02% of glucose, 4.35% of yeast extract, and 7.41% ascorbic acid where ascorbic acid was most effective. The maximum activity of β-glucosidase predicted by the RSM was 15.34 U/mg, which was similar to the experimental value 14.90 U/mg at the 16th day of incubation. This optimized activity of β-glucosidase was 23.6 times higher than the preliminary activity value, 0.63 U/mg, and was also much higher than previous values reported in other fungi strains. Therefore, a simplified medium supplemented with a cheap vitamin source, such as ascorbic acid, could be a cost effective mean of increasing β-glucosidase activity. PMID:25892916

  14. Inefficient Driving of Bulk Turbulence By Active Galactic Nuclei in a Hydrodynamic Model of the Intracluster Medium

    NASA Astrophysics Data System (ADS)

    Reynolds, Christopher S.; Balbus, Steven A.; Schekochihin, Alexander A.

    2015-12-01

    Central jetted active galactic nuclei (AGNs) appear to heat the core regions of the intracluster medium (ICM) in cooling-core galaxy clusters and groups, thereby preventing a cooling catastrophe. However, the physical mechanism(s) by which the directed flow of kinetic energy is thermalized throughout the ICM core remains unclear. We examine one widely discussed mechanism whereby the AGN induces subsonic turbulence in the ambient medium, the dissipation of which provides the ICM heat source. Through controlled inviscid three-dimensional hydrodynamic simulations, we verify that explosive AGN-like events can launch gravity waves (g-modes) into the ambient ICM, which in turn decays to volume-filling turbulence. In our model, however, this process is found to be inefficient, with less than 1% of the energy injected by the AGN activity actually ending up in the turbulence of the ambient ICM. This efficiency is an order of magnitude or more too small to explain the observations of AGN-feedback in galaxy clusters and groups with short central cooling times. Atmospheres in which the g-modes are strongly trapped/confined have an even lower efficiency since, in these models, the excitation of turbulence relies on the g-modes’ ability to escape from the center of the cluster into the bulk ICM. Our results suggest that, if AGN-induced turbulence is indeed the mechanism by which the AGN heats the ICM core, its driving may rely on physics beyond that captured in our ideal hydrodynamic model.

  15. Pochonia chlamydosporia fungal activity in a solid medium and its crude extract against eggs of Ascaridia galli.

    PubMed

    Braga, F R; Araújo, J V; Araujo, J M; Frassy, L N; Tavela, A O; Soares, F E F; Carvalho, R O; Queiroz, L M; Queiroz, J H

    2012-09-01

    The present study aimed to evaluate the ovicidal activity (type 3 effect) of VC1 and VC4 isolates of Pochonia chlamydosporia in a solid medium and the action of a crude extract of P. chlamydosporia against eggs of Ascaridia galli. To evaluate ovicidal activity in culture medium, 1000 A. galli eggs were plated on Petri dishes containing 2% water-agar with grown fungal isolates (VC1 or VC4) and without fungus (control group) and were examined at 1, 3 and 5 days post-inoculation (assay A). Then, to test the action of crude extracts of P. chlamydosporia (VC1 or VC4), 500 eggs of A. galli were plated on Petri dishes of 4.5 cm diameter with 5 ml of fungal filtrate from each tested isolate. The control group consisted of 500 eggs of A. galli with 10 ml of distilled water on each Petri dish (assay B). Fungal isolates were effective (P < 0.01) at destroying these eggs, showing a type 3 effect at the studied intervals. On the other hand, the crude extract of isolates (VC1 or VC4) reduced the number of A. galli eggs in the treated group compared with the control group by 64.1% and 56.5%, respectively. The results of the present study show that P. chlamydosporia is effective at destroying eggs of A. galli and could therefore be used in the biological control of nematodes. PMID:21838959

  16. Plasma-activated medium induces A549 cell injury via a spiral apoptotic cascade involving the mitochondrial-nuclear network.

    PubMed

    Adachi, Tetsuo; Tanaka, Hiromasa; Nonomura, Saho; Hara, Hirokazu; Kondo, Shin-ichi; Hori, Masaru

    2015-02-01

    Plasma medicine is a rapidly expanding new field of interdisciplinary research that combines physics, chemistry, biology, and medicine. Nonthermal atmospheric pressure plasma can be applied to living cells and tissues and has emerged as a novel technology for cancer therapy. Plasma has recently been shown to affect cells not only directly, but also by indirect treatment with previously prepared plasma-activated medium (PAM). The objective of this study was to demonstrate the inhibitory effects of PAM on A549 cell survival and elucidate the signaling mechanisms responsible for cell death. PAM maintained its ability to suppress cell viability for at least 1 week when stored at -80°C. The severity of PAM-triggered cell injury depended on the kind of culture medium used to prepare the PAM, especially that with or without pyruvate. Hydrogen peroxide (H2O2) and/or its derived or cooperating reactive oxygen species reduced the mitochondrial membrane potential, downregulated the expression of the antiapoptotic protein Bcl2, activated poly(ADP-ribose) polymerase-1, and released apoptosis-inducing factor from mitochondria with endoplasmic reticulum stress. However, the activation of caspase 3/7 and attenuation of cell viability by the addition of caspase inhibitor were not observed. The accumulation of adenine 5'-diphosphoribose as a product of the above reactions activated transient receptor potential melastatin 2, which elevated intracellular Ca(2+) levels and subsequently led to cell death. These results demonstrated that H2O2 and/or other reactive species in PAM disturbed the mitochondrial-nuclear network in cancer cells through a caspase-independent apoptotic pathway. Moreover, damage to the plasma membrane by H2O2-cooperating charged species not only induced apoptosis, but also increased its permeability to extracellular reactive species. These phenomena were also detected in PAM-treated HepG2 and MCF-7 cells. PMID:25433364

  17. Influence of the active nucleus on the multiphase interstellar medium in NGC 1068

    NASA Technical Reports Server (NTRS)

    Bland-Hawthorn, Jonathan; Weisheit, Jon; Cecil, Gerald; Sokolowski, James

    1993-01-01

    The luminous spiral NGC 1068 has now been imaged from x-ray to radio wavelengths at comparably high resolution (approximately less than 5 in. FWHM). The bolometric luminosity of this well-known Seyfert is shared almost equally between the active nucleus and an extended 'starburst' disk. In an ongoing study, we are investigating the relative importance of the nucleus and the disk in powering the wide range of energetic activity observed throughout the galaxy. Our detailed analysis brings together a wealth of data: ROSAT HRI observations, VLA lambda lambda 6-20 cu cm and OVRO interferometry, lambda lambda 0.4-10.8 micron imaging, and Fabry-Perot spectrophotometry.

  18. Mechanism of dark decomposition of iodine donor in the active medium of a pulsed chemical oxygen - iodine laser

    SciTech Connect

    Andreeva, Tamara L; Kuznetsova, S V; Maslov, A I; Sorokin, Vadim N

    2002-06-30

    A scheme is proposed that describes the dark decomposition of iodide - the donor of iodine - and the relaxation of singlet oxygen in the chlorine-containing active medium of a pulsed chemical oxygen - iodine laser (COIL). For typical compositions of the active media of pulsed COILs utilising CH{sub 3}I molecules as iodine donors, a branching chain reaction of the CH{sub 3}I decomposition accompanied by the efficient dissipation of singlet oxygen is shown to develop even at the stage of filling the active volume. In the active media with CF{sub 3}I as the donor, a similar chain reaction is retarded due to the decay of CF{sub 3} radicals upon recombination with oxygen. The validity of this mechanism is confirmed by a rather good agreement between the results of calculations and the available experimental data. The chain decomposition of alkyliodides accompanied by an avalanche production of iodine atoms represents a new way of efficient chemical production of iodine for a COIL. (active media)

  19. Activation analysis with short- and medium-lived radionuclides for the supervision of incineration plants

    SciTech Connect

    Grass, F.

    1992-01-01

    Incineration plants are needed to cope with the enormous volumes of waste produced by modern society in highly industrialized countries. These plants employ modern filter systems such as electrostatic filters for the deposition of aerosols and two-stage flue gas washing systems for the retention of volatile compounds. As garbage contains practically all the elements, the output streams should be surveyed by multielement methods. The current feasibility study shows that most of the toxic elements could be screened by activation analysis. This method could be applied with a minimum of sample preparation and is sufficiently fast and sensitive to meet the legislative requirements. Short-time activation analysis combined with an additional 2 h of irradiation fulfills the analytical requirements. The fast sample preparation outweighs the drawback of having to allow 24 to 36 h for decay and a 2-h measurement time.

  20. Effects of drying on nitrification activity in zeoponic medium used for long-term space missions

    NASA Technical Reports Server (NTRS)

    McGilloway, R. L.; Weaver, R. W.

    2004-01-01

    One component of a proposed life support system is the use of zeoponic substrates, which slowly release NH4+ into "soil" solution, for the production of plants. Nitrifying bacteria that convert NH4+ to NO3- are among the important microbial components of these systems. Survival of nitrifying bacteria in dry zeoponic substrates is needed, because the substrate would likely be stored in an air-dry state between croppings. Substrate was enriched for nitrifying bacteria and allowed to air-dry in a laminar flow hood. Stored substrate was analyzed for nitrifier survivability by measuring nitrifier activity at the beginning, 3 days, 1, 2, and 3 weeks. After rewetting, activity was approximately 9 micrograms N g-1 h-1 regardless of storage time. Nitrification rates did not decrease during storage. It seems unlikely that drying between plantings would result in practical reductions in nitrification, and reinoculation with nitrifying bacteria would not be necessary.

  1. Generation of unipolar optical pulses in a Raman-active medium

    NASA Astrophysics Data System (ADS)

    Arkhipov, R. M.; Arkhipov, M. V.; Belov, P. A.; Tolmachev, Yu A.; Babushkin, I.

    2016-04-01

    Response of a Raman-active media (RAM) to the excitation by a series of ultrashort (few-cycle) optical pulses propagating at a superluminal velocity is studied theoretically. It is shown that under certain conditions rectangular unipolar pulses (video-pulses) can be generated as the RAM response. The duration, shape and amplitude of these video-pulses can be widely tuned by modifying the pump pulse parameters.

  2. Mature cathepsin L is substantially active in the ionic milieu of the extracellular medium.

    PubMed

    Dehrmann, F M; Coetzer, T H; Pike, R N; Dennison, C

    1995-12-01

    The activity of cathepsin L is affected by ionic strength, resulting in the measured pH optimum being higher in acetate-4-morpholineethane sulfonic acid (MES)-Tris buffers of constant ionic strength than in phosphate buffers of constant molarity (and hence varying ionic strength). In acetate-MES-Tris and phosphate buffers of constant ionic strength across the pH range, the catalytic constant, kcat, generally peaked at ca. pH 6.5 and essentially independently of ionic strength. Km values, of ca. 5 microM, manifested a slight rising trend with increasing ionic strength, with a sharp increase to 20-25 microM, specifically at pH 6.5 and I = 0.4. At physiological ionic strengths, the specific buffer ions present affected the activity of mature cathepsin L, kcat/Km declining above pH 6.5 in phosphate buffer, but only above pH 7 in acetate-MES-Tris buffer. In Hanks' balanced salt solution, a model of the extracellular fluid, measured values at pH 7.2 were kcat, 18.9 s-1; Km, 13.5 microM; and kcat/Km, 1.4 x 10(6) M-1 s-1. The stability of cathepsin L in the physiological pH range was also differentially affected by the specific buffer ions, generally in parallel with the enzyme activity. In Hanks' balanced salt solution, mature cathepsin L was substantially active and stable, having a half-life of 179 s at pH 7.2 and 657 s at pH 6.8 (the peritumor pH). PMID:7503566

  3. Catalytic activity of zymomonas mobilis extracellular "levan-levansucrase" complex in sucrose medium.

    PubMed

    Bekers, M; Upite, D; Kaminska, E; Laukevics, J; Ionina, R; Vigants, A

    2003-01-01

    The fructan biosynthesis by ethanol sedimented "levan-levansucrase" complex from Zymomonas mobilis fermentation broth as well as purified levansucrase was investigated. The fructooligosaccharide (FOS) producing activity of "levan-levamsucrase" sediment was investigated in 55% sucrose syrup at 45 degrees C. It was shown that FOS in the syrup were presented by 1-kestose, 6-kestose, neokestose and nystose. The increase of gluconic acid concentration was observed in the reaction mixture during the incubation suggesting about presence of glucose/fructose oxidoreductase in "levan-levansucrase" sediment. The influence of ethanol, glycerol and NaCl on levan and fructooligosaccharide formation by "levan-levansucrase" complex and purified levansucrase was studied and the changes in the ratio between different activities of levansucrase (sucrose hydrolysis, levan biosynthesis and FOS formation) were observed. Ethanol increases the FOS biosynthesis part in total activity of purified levansucrase. The technology of the production of prebiotics containing food product--fructan syrup by "levan-levansucrase " sediment as biocatalyst was developed. PMID:15296187

  4. Minimization of corrosion using activated sodium bromide in a medium-size cooling tower

    SciTech Connect

    Nalepa, C.J.; Moore, R.M.; Golson, G.L.; Wolfe, T.W.; Puckorius, P.R.

    1996-07-01

    The cooling tower at the Albermarle Process Development Center in Baton Rouge, Louisiana, historically used chlorine as a biocide in combination with phosphorus-based corrosion/scale inhibitors. Although this regimen provided biocontrol, sludge and iron buildup was a problem in low-velocity, small cross-sectional areas of piping. A general cleanup of the system was performed in April 1995. This cleanup was followed with a switch to a two-component corrosion inhibitor/dispersant package. Alternate biocides were evaluated at this time. Activated sodium bromide was found to be particularly effective in this tower, which operates at pH {approximately}8.4. Relative to chlorine, the use of activated sodium bromide led to a decrease in general and pitting corrosion on mild steel. The reduced corrosion appears to be due to a combination of both chemical (less attack on passivated metal surfaces) and biological factors (better control of heterotrophic and sessile bacteria). These conclusions are supported by chemical analyses, corrosion meter and coupon data, dip slides, biological activity reaction tests, and visual observations of the tower sump and heat exchanger surfaces.

  5. Case study: Minimization of corrosion using activated sodium bromide in a medium-size cooling tower

    SciTech Connect

    Nalepa, C.J.; Moore, R.M.; Golson, G.L.; Wolfe, T.W.; Puckorius, P.R.

    1996-10-01

    The process loop cooling tower at the Albemarle Process Development Center in Baton Rouge, LA has historically used chlorine as the biocide together with industry accepted phosphorus-based corrosion/scale inhibitors. Although this regimen provided biocontrol, sludge and iron build-up was a recurring problem, especially in low-velocity, small cross-sectional areas of piping. A general clean-up of the system was performed in April, 1995. This clean-up was followed with a switch to a two-component corrosion inhibitor/dispersant package. It was decided to study alternate biocides as well at this time. Activated sodium bromide was found to be particularly effective in this tower, which operates at pH {approximately}8.4. Relative to chlorine, the use of activated sodium bromide led to a decrease in general and pitting corrosion on mild steel while maintaining prior performance on admiralty brass. The reduced corrosion appears to be due to a combination of both chemical (less attack on passivated metal surfaces) and biological factors (better control of heterotrophic and sessile bacteria). These conclusions are supported by chemical analyses, corrosion meter and coupon data, dip slides, BART (biological activity reaction test) tests, and visual observations of the tower sump and heat exchanger surfaces.

  6. Relation between bacterial strain resistance to solvents and biodesulfurization activity in organic medium.

    PubMed

    Bouchez-Naïtali, Murielle; Abbad-Andaloussi, Samir; Warzywoda, Michel; Monot, Frédéric

    2004-09-01

    Microorganisms used in biodesulfurization of petroleum products have to withstand high concentrations of hydrocarbons. The capacities of seven desulfurizing strains of Rhodococcus to be active in the presence of solvents were evaluated. Octanol and toluene (log P=2.9) were selected as toxic solvents. The effect of the solvents was determined by measuring either inhibition of growth or the decrease in respiratory activity of the cells. Differences among strains in their resistance to solvent responses were observed, but these variations were dependent on the test used. Resistance to solvents was then compared to the capacity of the different strains to retain biodesulfurization activity in the presence of hexadecane. Inhibition of desulfurization by high concentrations of hexadecane was found to be well correlated to the sensitivity of the strains to respiration inhibition by toluene, but not to growth inhibition. This result also showed that the respirometric test was a rapid and reliable test to select solvent-resistant strains for use as resting cells in biocatalysis processes, such as biodesulfurization, in organic media. PMID:15133641

  7. Plasma-activated medium-induced intracellular zinc liberation causes death of SH-SY5Y cells.

    PubMed

    Hara, Hirokazu; Taniguchi, Miko; Kobayashi, Mari; Kamiya, Tetsuro; Adachi, Tetsuo

    2015-10-15

    Plasma is an ionized gas consisting of ions, electrons, free radicals, neutral particles, and photons. Plasma-activated medium (PAM), which is prepared by the irradiation of cell-free medium with non-thermal atmospheric pressure plasma, induces cell death in various types of cancer cell. Since PAM contains reactive oxygen species (ROS), its anti-cancer effects are thought to be attributable to oxidative stress. Meanwhile, oxidative stress has been shown to induce the liberation of zinc (Zn(2+)) from intracellular Zn(2+) stores and to provoke Zn(2+)-dependent cell death. In this study, we thus examined whether Zn(2+) is involved in PAM-induced cell death using human neuroblastoma SH-SY5Y cells. Exposure to PAM triggered cell death in SH-SY5Y cells. The cell-permeable Zn(2+) chelator N,N,N',N'-tetrakis(2-pyridinylmethyl)-1,2-ethanediamine (TPEN) protected against PAM-induced cell death. Zn(2+) imaging using the fluorescent Zn(2+) probe FluoZin-3 revealed that PAM elicited a rise of intracellular free Zn(2+). In addition, PAM stimulated PARP-1 activation, mitochondrial ROS generation, and the depletion of intracellular NAD(+) and ATP. These findings suggest that PAM-induced PARP-1 activation causes energy supply exhaustion. Moreover, TPEN suppressed all of these events elicited by PAM. Taken together, we demonstrated here that Zn(2+) released from intracellular Zn(2+) stores serves as a key mediator of PAM-induced cell death in SH-SY5Y cells. PMID:26319292

  8. Lasing properties of active medium based on sulforhodamine 101 incorporated into commercial polyurethane compound

    SciTech Connect

    Nikolaev, S V; Pozhar, V V; Dzyubenko, M I

    2011-01-24

    The lasing properties of polymer matrices based on commercial polyurethane compound activated by sulforhodamine 101 dye are studied. Lasing with an efficiency of 26 % and pulse energy of 76 mJ is obtained using microsecond transverse pumping at a wavelength of 587 nm. The service life (time of operation to a decrease in the output energy by 50 % upon excitation by 0.3 J cm{sup -2} pulses) amounts to 2500 pulses. A particular attention is given to the bichromatic lasing spectra of the samples tested. Based on the experimental data a model explaining the two-band emission spectrum is proposed and discussed. (lasers and amplifiers)

  9. The aqueous-polyelectrolyte dye solution as an active laser medium

    SciTech Connect

    Akimov, A I; Saletskii, A M

    2000-11-30

    The spectral, luminescent, and lasing properties of aqueous solutions of a cationic dye rhodamine 6G with additions of anion polyelectrolytes - polyacrylic and polymethacrylic acids - are studied. It is found that the energy and spectral properties of lasing of these solutions depend on the ratio of concentrations of polyelectrolyte and molecules. It is also found that the lasing parameters of aqueous-polyelectrolyte dye solutions can be controlled by changing the structure of the molecular system. The variation in the structure of aqueous-polyelectrolyte dye solutions of rhodamine 6G resulted in an almost five-fold increase in the lasing efficiency compared to that in aqueous dye solutions. (lasers, active media)

  10. Nonlinear optical properties of the active medium in intracavity phase conjugation of the radiation of a pulsed electron-beam-controlled discharge CO{sub 2} laser. II. Theoretical analysis

    SciTech Connect

    Galushkin, M G; Mitin, Konstantin V; Ionin, Andrei A; Kotkov, A A

    1998-10-31

    Numerical simulation is used as the basis of an analysis of nonlinear optical properties of the active medium in intracavity four-wave mixing of the radiation of a pulsed electron-beam-controlled discharge CO{sub 2} laser on saturated-gain and refractive-index diffraction gratings. The reflection coefficient of the phase-conjugated signal is determined for various cavity Q-factors, specific input energies, and pressures of the laser-active mixture. A comparison is made of the theoretical and experimental results. It is found that the rate of formation of amplitude gratings is governed primarily by the initial population inversion and by the intensities of the interacting waves. It is shown that transient phase gratings make the dominant contribution to the phase-conjugate reflection coefficient at high pressures of the mixture. (nonlinear optical phenomena)

  11. Influence of liquid medium on the activity of a low-alpha Fischer-Tropsch catalyst

    SciTech Connect

    Gormley, R.J.; Zarochak, M.F.; Deffenbaugh, P.W.; Rao, K.R.P.M.

    1995-12-31

    The purpose of this research was to measure activity, selectivity, and the maintenance of these properties in slurry autoclave experiments with a Fischer-Tropsch (FT) catalyst that was used in the {open_quotes}FT II{close_quotes} bubble-column test, conducted at the Alternative Fuels Development Unit (AFDU) at LaPorte, Texas during May 1994. The catalyst contained iron, copper, and potassium and was formulated to produce mainly hydrocarbons in the gasoline range with lesser production of diesel-range products and wax. The probability of chain growth was thus deliberately kept low. Principal goals of the autoclave work have been to find the true activity of this catalyst in a stirred tank reactor, unhindered by heat or mass transfer effects, and to obtain a steady conversion and selectivity over the approximately 15 days of each test. Slurry autoclave testing of the catalyst in heavier waxes also allows insight into operation of larger slurry bubble column reactors. The stability of reactor operation in these experiments, particularly at loadings exceeding 20 weight %, suggests the likely stability of operations on a larger scale.

  12. Everyone Gains: Extracurricular Activities in High School and Higher SAT® Scores. Research Report No. 2005-2

    ERIC Educational Resources Information Center

    Everson, Howard T.; Millsap, Roger E.

    2005-01-01

    This report presents evidence that links participation in extracurricular activities (ECAs) in high school with higher SAT Reasoning Test™ (SAT®) scores. Using structural equation models (SEMs) with latent means, we analyzed data from a national sample of college-bound high school students. A series of structural equation models--isolating the…

  13. Medium-frequency impulsive-thrust-activated liquid hydrogen reorientation with Geyser

    NASA Technical Reports Server (NTRS)

    Hung, R. J.; Shyu, K. L.

    1992-01-01

    Efficient technique are studied for accomplishing propellant resettling through the minimization of propellant usage through impulsive thrust. A comparison between the use of constant-thrust and impulsive-thrust accelerations for the activation of propellant resettlement shows that impulsive thrust is superior to constant thrust for liquid reorientation in a reduced-gravity environment. This study shows that when impulsive thrust with 0.1-1.0-, and 10-Hz frequencies for liquid-fill levels in the range between 30-80 percent is considered, the selection of 1.0-Hz-frequency impulsive thrust over the other frequency ranges of impulsive thrust is the optimum. Characteristics of the slosh waves excited during the course of 1.0-Hz-frequency impulsive-thrust liquid reorientation were also analyzed.

  14. Cardiovascular responses to peripheral chemoreflex activation and comparison of different methods to evaluate baroreflex gain in conscious mice using telemetry.

    PubMed

    Braga, Valdir A; Burmeister, Melissa A; Sharma, Ram V; Davisson, Robin L

    2008-10-01

    Peripheral chemoreceptors located in the carotid bodies are the primary sensors of systemic hypoxia. Although the pattern of responses elicited by peripheral chemoreceptor activation is well established in rats, lambs, and rabbits, the cardiovascular responses to peripheral chemoreflex activation in conscious mice have not been delineated. Here we report that stimulation of peripheral chemoreceptors by potassium cyanide (KCN) in conscious mice elicits a unique biphasic response in blood pressure that is characterized by an initial and robust rise followed by a decrease in blood pressure, which is accompanied by a marked reduction in heart rate. The depressor and bradycardic responses to KCN were abolished by muscarinic receptor blockade with atropine, and the pressor response was abolished by alpha-adrenergic receptor blockade with prazosin, suggesting that vagal and sympathetic drive to the heart and sympathetic drive to the vasculature mediate these cardiovascular responses. These studies characterized the chemoreflex in conscious mice and established the reliability of using them for studying hypoxia-related diseases such as obstructive sleep apnea. In another series of experiments, two methods for analyzing baroreflex sensitivity were compared: the classical pharmacological approach using phenylephrine and sodium nitroprusside (i.e., the Oxford technique) or the sequence method for analyzing spontaneous baroreflex activity. Our findings indicate that both methods are reliable, and the sequence method certainly has its benefits as a predictive tool in the context of long-term noninvasive studies using telemetry. However, for absolute determination of baroreflex function, analysis of spontaneous baroreflex activity should be complemented by the classical pharmacological method. PMID:18667715

  15. Chloroplast ultra structure, photosynthesis and enzyme activities in regenerated plants of Stevia rebaudiana (Bert.) Bertoni as influenced by copper sulphate in the medium.

    PubMed

    Jain, Pourvi; Kachhwaha, Sumita; Kothari, S L

    2014-09-01

    Stevia rebaudiana (Bert.) Bertoni is an important medicinal plant used as noncaloric commercial sweetener. Plants regenerated with higher levels of copper sulphate in the medium exhibited enhanced activity of peroxidase and polyphenoloxidase (PPO) enzymes. Transmission electron microscopy (TEM) revealed increase in size and number of electron dense inclusions in the chloroplasts of plants regenerated at optimised level of copper sulphate (0.5 microM) in the medium. There was decrease in chlorogenic acid (CGA) content. Chl-a-fluorescence transient pattern (OJIP) showed that the photosynthesis process was more efficient at 0.5 microM CuSO4 in the medium. PMID:25241590

  16. Proton Reaction Data Library for Nuclear Activation (Medium Energy Nuclear Data Library.)

    2002-03-01

    Version 00 GROUPXS does file handling and processing of the double-differential continuum-emission cross sections stored in the new MF6 format of ENDF/VI. It treats the energy-angle data that are supposed to be represented by a Legendre-polynomial expansion in the center-of-mass system and can do the following: (1) Conversion of MF6 data from center-of-mass system to the laboratory system, with the possibility to continue the calculation with the options (2), (3), and (4). (2) Conversion ofmore » Legendre-polynomial representation into point-wise angular data, in MF6 format. (3) Conversion of data from MF6 into MF4 + MF5 (ENDF-V). (4) Calculation of group constants, scattering matrices and transfer matrices for arbitrary group structures with a fusion micro-flux weighting spectrum (PN-approximation). The code treats only continuum reaction types that are stored in the MF6 format with the restrictions as specified for the European Fusion File (EFF1). These restrictions are not inconvenient for the purpose of fusion neutronics calculations and they facilitate relatively simple processing . This neutron reaction data library can be used for nuclear activation and transmutation applications at energies up to 100 MeV.« less

  17. A novel medium-energy ion emitter for active spacecraft potential control

    NASA Astrophysics Data System (ADS)

    Schmidt, R.; Arends, H.; Pedersen, A.; Fehringer, M.; Ruedenauer, F.; Steiger, W.; Narheim, B. T.; Svenes, R.; Kvernsveen, K.; Tsuruda, K.

    1993-08-01

    An ion emission instrument has been developed to actively control the electrostatic surface potential of a spacecraft in orbit. Spacecraft surfaces tend to charge positive when their conductive surfaces are partially sunlit, and photoelectrons emitted, and the spacecraft is positioned outside the very dense plasma region which is referred to as the plasmasphere. A small, lightweight instrument with a lifetime of more than 10,000 h at a nominal emission current of 10 micro-A was the design goal. The ion emitter is based on the liquid metal ion source principle; a constant stream of liquified indium is evaporated from the tip of a needle and ionized; the ions are then extracted by a strong electric field. The size of the instrument is about 18 by 15 by 23 cm (length x width x height) and the entire instrument weighs about 1.9 kg and consumes 2.4 W of electrical power in the nominal emission mode. An instrument of this type is already operational on the Japanese Geotail spacecraft, while five more instruments are at the stage of flight model assembly for integration on the Russian Interball satellite and the ESA/NASA four-spacecraft Cluster Mission. The Geotail instrument is functioning as expected. Preliminary results show that the ion emitter is able to reduce surface potentials of +70 V (highest value observed up to now) down to 2-4 V.

  18. Liquid crystals with patterned molecular orientation as an electrolytic active medium.

    PubMed

    Peng, Chenhui; Guo, Yubing; Conklin, Christopher; Viñals, Jorge; Shiyanovskii, Sergij V; Wei, Qi-Huo; Lavrentovich, Oleg D

    2015-11-01

    Transport of fluids and particles at the microscale is an important theme in both fundamental and applied science. One of the most successful approaches is to use an electric field, which requires the system to carry or induce electric charges. We describe a versatile approach to generate electrokinetic flows by using a liquid crystal (LC) with surface-patterned molecular orientation as an electrolyte. The surface patterning is produced by photoalignment. In the presence of an electric field, the spatially varying orientation induces space charges that trigger flows of the LC. The active patterned LC electrolyte converts the electric energy into the LC flows and transport of embedded particles of any type (fluid, solid, gaseous) along a predesigned trajectory, posing no limitation on the electric nature (charge, polarizability) of these particles and interfaces. The patterned LC electrolyte exhibits a quadratic field dependence of the flow velocities; it induces persistent vortices of controllable rotation speed and direction that are quintessential for micro- and nanoscale mixing applications. PMID:26651712

  19. Liquid crystals with patterned molecular orientation as an electrolytic active medium

    NASA Astrophysics Data System (ADS)

    Peng, Chenhui; Guo, Yubing; Conklin, Christopher; Viñals, Jorge; Shiyanovskii, Sergij V.; Wei, Qi-Huo; Lavrentovich, Oleg D.

    2015-11-01

    Transport of fluids and particles at the microscale is an important theme in both fundamental and applied science. One of the most successful approaches is to use an electric field, which requires the system to carry or induce electric charges. We describe a versatile approach to generate electrokinetic flows by using a liquid crystal (LC) with surface-patterned molecular orientation as an electrolyte. The surface patterning is produced by photoalignment. In the presence of an electric field, the spatially varying orientation induces space charges that trigger flows of the LC. The active patterned LC electrolyte converts the electric energy into the LC flows and transport of embedded particles of any type (fluid, solid, gaseous) along a predesigned trajectory, posing no limitation on the electric nature (charge, polarizability) of these particles and interfaces. The patterned LC electrolyte exhibits a quadratic field dependence of the flow velocities; it induces persistent vortices of controllable rotation speed and direction that are quintessential for micro- and nanoscale mixing applications.

  20. Probing the circumgalactic medium of active galactic nuclei with background quasars

    NASA Astrophysics Data System (ADS)

    Kacprzak, Glenn G.; Churchill, Christopher W.; Murphy, Michael T.; Cooke, Jeff

    2015-01-01

    We performed a detailed study of the extended cool gas, traced by Mg II absorption [Wr(2796) ≥ 0.3 Å], surrounding 14 narrow-line active galactic nuclei (AGNs) at 0.12 ≤ z ≤ 0.22 using background quasar sightlines. The background quasars probe the AGNs at projected distances of 60 ≤ D ≤ 265 kpc. We find that, between 100 ≤ D ≤ 200 kpc, AGNs appear to have lower Mg II gas covering fractions (0.09^{+0.18}_{-0.08}) than quasars (0.47^{+0.16}_{-0.15}) and possibly lower than inactive field galaxies (0.25^{+0.11}_{-0.09}). We do not find a statistically significant azimuthal angle dependence for the Mg IIcovering fraction around AGNs, though the data hint at one. We also study the `down-the-barrel' outflow properties of the AGNs themselves and detect intrinsic Na ID absorption in 8/8 systems and intrinsic Mg II absorption in 2/2 systems, demonstrating that the AGNs have significant reservoirs of cool gas. We find that 6/8 Na ID and 2/2 Mg II intrinsic systems contain blueshifted absorption with Δv > 50 km s-1, indicating outflowing gas. The 2/2 intrinsic Mg II systems have outflow velocities a factor of ˜4 higher than the Na ID outflow velocities. Our results are consistent with AGN-driven outflows destroying the cool gas within their haloes, which dramatically decreases their cool gas covering fraction, while starburst-driven winds are expelling cool gas into their circumgalactic media (CGM). This picture appears contrary to quasar-quasar pair studies which show that the quasar CGM contains significant amounts of cool gas whereas intrinsic gas found `down-the-barrel' of quasars reveals no cool gas. We discuss how these results are complementary and provide support for the AGN unified model.

  1. A Transformerless Hybrid Active Filter Capable of Complying with Harmonic Guidelines for Medium-Voltage Motor Drives

    NASA Astrophysics Data System (ADS)

    Kondo, Ryota; Akagi, Hirofumi

    This paper presents a transformerless hybrid active filter that is integrated into medium-voltage adjustable-speed motor drives for fans, pumps, and compressors without regenerative braking. The authors have designed and constructed a three-phase experimental system rated at 400V and 15kW, which is a downscaled model from a feasible 6.6-kV 1-MW motor drive system. This system consists of the hybrid filter connecting a passive filter tuned to the 7th harmonic filter in series with an active filter that is based on a three-level diode-clamped PWM converter, as well as an adjustable-speed motor drive in which a diode rectifier is used as the front end. The hybrid filter is installed on the ac side of the diode rectifier with no line-frequency transformer. The downscaled system has been exclusively tested so as to confirm the overall compensating performance of the hybrid filter and the filtering performance of a switching-ripple filter for mitigating switching-ripple voltages produced by the active filter. Experimental results verify that the hybrid filter achieves harmonic compensation of the source current in all the operating regions from no-load to the rated-load conditions, and that the switching-ripple filter reduces the switching-ripple voltages as expected.

  2. Comparison of antimicrobial activities of newly obtained low molecular weight scorpion chitosan and medium molecular weight commercial chitosan.

    PubMed

    Kaya, Murat; Asan-Ozusaglam, Meltem; Erdogan, Sevil

    2016-06-01

    In this study the antimicrobial activity of low molecular weight (3.22 kDa) chitosan, obtained for the first time from a species belonging to the Scorpiones, was screened against nine pathogenic microorganisms (seven bacteria and two yeasts) and compared with that of medium molecular weight commercial chitosan (MMWCC). It was observed that the antimicrobial activity of the low molecular weight scorpion chitosan (LMWSC) was specific to bacterial species in general rather than gram-negative or gram-positive bacterial groups. It was also determined that LMWSC had a stronger inhibitory effect than the MMWCC, particularly on the bacterium Listeria monocytogenes and the yeast Candida albicans, which are important pathogens for public health. In addition, it was recorded that the MMWCC had a greater inhibitory effect on Bacillus subtilis than LMWSC. According to the results obtained by the disc diffusion method, the antibacterial activity of both LMWSC and MMWCC against B. subtilis and Salmonella enteritidis was higher than the widely used antibiotic Gentamicin (CN, 10 μg/disc). PMID:26702952

  3. Simulations of the kinetics of the active medium of an X-ray laser heated by high-power picosecond pulses

    SciTech Connect

    Politov, V Yu; Lykov, V A; Shinkarev, M K

    2000-12-31

    The gain on the 3S - 3P transitions of Ne-like ions produced upon material heating by high-power picosecond laser pulses was numerically simulated. The dependence of the gain on the average value of the nuclear charge Z and the irradiation intensity was investigated. The shortest wavelength of X-rays that can be produced from the plasma of Ne-like ions was predicted. (active media)

  4. Collapsible high gain antenna

    NASA Technical Reports Server (NTRS)

    Cribb, H. E. (Inventor)

    1973-01-01

    A lightweight small high gain antenna which is capable of being packaged in a collapsed form and automatically expanded when in use is described. The antenna includes a cylindrical housing having a rod with a piston adjacent to one end extending through it. Attached to the outer end of the rod in a normally collapsed state is a helical wire coil. When the gas producing means is activated the piston and rod are shifted outwardly to expand the wire coil. A latch is provided for holding the helical coil in the expanded position.

  5. Effects of Human Activities on the Composition of Organic Carbon in Estuaries: Insights Gained Through Lipid Biomarker Studies

    NASA Astrophysics Data System (ADS)

    Canuel, E. A.

    2002-12-01

    Applications of organic geochemistry have expanded in recent decades to include studies within fields as diverse as ecology and ecosystem science, biogeochemistry, and environmental geochemistry. In part, this expansion has occurred in response to increasing human impacts on the environment which are manifested to a large extent in freshwater and estuarine environments. Human influences to these regions include alterations in carbon and nutrient flow, changes in sedimentation and the introduction of industrial and petroleum products. Organic geochemists bring new tools and insights to these areas improving our ability to trace specific components of organic matter. These approaches have the capacity to improve our understanding of the role nearshore regions play in the global carbon cycle, better identification of the sources and mode of delivery of natural and anthropogenic organic molecules, and an improved understanding of the fate of organic molecules including remineralization, transformation, or burial in sediments. Chesapeake Bay and San Francisco Bay are the largest estuaries in the continental U.S.A. and provide an interesting comparison for understanding processes influencing the composition of estuarine particulate organic matter (POM). Both estuaries have also been heavily impacted by human activities thus providing an opportunity to investigate how anthropogenic activities influence POM quantity and quality. Results from biomarker analysis of suspended POM and surficial sediments collected from each estuary will be presented and summarized in this talk. Stable isotopic signatures and lipid biomarker compounds reveal spatial variations in organic matter sources along the salinity continuum of each estuary with a stronger terrigeneous signature at the freshwater end-member. In addition, temporal variations in freshwater inflow and phytoplankton production influenced the sources and reactivity of POM. This talk will demonstrate that results from biomarker

  6. Natural Killer Cell-Based Therapies Targeting Cancer: Possible Strategies to Gain and Sustain Anti-Tumor Activity

    PubMed Central

    Dahlberg, Carin I. M.; Sarhan, Dhifaf; Chrobok, Michael; Duru, Adil D.; Alici, Evren

    2015-01-01

    Natural killer (NK) cells were discovered 40 years ago, by their ability to recognize and kill tumor cells without the requirement of prior antigen exposure. Since then, NK cells have been seen as promising agents for cell-based cancer therapies. However, NK cells represent only a minor fraction of the human lymphocyte population. Their skewed phenotype and impaired functionality during cancer progression necessitates the development of clinical protocols to activate and expand to high numbers ex vivo to be able to infuse sufficient numbers of functional NK cells to the cancer patients. Initial NK cell-based clinical trials suggested that NK cell-infusion is safe and feasible with almost no NK cell-related toxicity, including graft-versus-host disease. Complete remission and increased disease-free survival is shown in a small number of patients with hematological malignances. Furthermore, successful adoptive NK cell-based therapies from haploidentical donors have been demonstrated. Disappointingly, only limited anti-tumor effects have been demonstrated following NK cell infusion in patients with solid tumors. While NK cells have great potential in targeting tumor cells, the efficiency of NK cell functions in the tumor microenvironment is yet unclear. The failure of immune surveillance may in part be due to sustained immunological pressure on tumor cells resulting in the development of tumor escape variants that are invisible to the immune system. Alternatively, this could be due to the complex network of immune-suppressive compartments in the tumor microenvironment, including myeloid-derived suppressor cells, tumor-associated macrophages, and regulatory T cells. Although the negative effect of the tumor microenvironment on NK cells can be transiently reverted by ex vivo expansion and long-term activation, the aforementioned NK cell/tumor microenvironment interactions upon reinfusion are not fully elucidated. Within this context, genetic modification of NK cells

  7. Natural Killer Cell-Based Therapies Targeting Cancer: Possible Strategies to Gain and Sustain Anti-Tumor Activity.

    PubMed

    Dahlberg, Carin I M; Sarhan, Dhifaf; Chrobok, Michael; Duru, Adil D; Alici, Evren

    2015-01-01

    Natural killer (NK) cells were discovered 40 years ago, by their ability to recognize and kill tumor cells without the requirement of prior antigen exposure. Since then, NK cells have been seen as promising agents for cell-based cancer therapies. However, NK cells represent only a minor fraction of the human lymphocyte population. Their skewed phenotype and impaired functionality during cancer progression necessitates the development of clinical protocols to activate and expand to high numbers ex vivo to be able to infuse sufficient numbers of functional NK cells to the cancer patients. Initial NK cell-based clinical trials suggested that NK cell-infusion is safe and feasible with almost no NK cell-related toxicity, including graft-versus-host disease. Complete remission and increased disease-free survival is shown in a small number of patients with hematological malignances. Furthermore, successful adoptive NK cell-based therapies from haploidentical donors have been demonstrated. Disappointingly, only limited anti-tumor effects have been demonstrated following NK cell infusion in patients with solid tumors. While NK cells have great potential in targeting tumor cells, the efficiency of NK cell functions in the tumor microenvironment is yet unclear. The failure of immune surveillance may in part be due to sustained immunological pressure on tumor cells resulting in the development of tumor escape variants that are invisible to the immune system. Alternatively, this could be due to the complex network of immune-suppressive compartments in the tumor microenvironment, including myeloid-derived suppressor cells, tumor-associated macrophages, and regulatory T cells. Although the negative effect of the tumor microenvironment on NK cells can be transiently reverted by ex vivo expansion and long-term activation, the aforementioned NK cell/tumor microenvironment interactions upon reinfusion are not fully elucidated. Within this context, genetic modification of NK cells

  8. Loop laser cavities with self-pumped phase-conjugate mirrors in low-gain active media for phase-locked multichannel laser systems

    SciTech Connect

    Basiev, Tasoltan T; Gavrilov, A V; Ershkov, M N; Smetanin, Sergei N; Fedin, Aleksandr V; Bel'kov, K A; Boreysho, A S; Lebedev, V F

    2011-03-31

    It is proved that lasers with different loop cavities with self-pumped phase-conjugate mirrors in low-gain active media can operate under injection of external laser radiation and can be used for the development of diode-pumped phase-locked multichannel neodymium laser systems operating both on the fundamental laser transition with the wavelength {lambda} = 1.06 {mu}m and on the transition with {lambda} = 1.34 {mu}m. The phase-conjugate oscillation thresholds in the case of injection of an external signal are determined for a multiloop cavity configuration and an increased number of active elements in the cavity. It is shown that phase-conjugate oscillation can occur even if the single-pass gain of the active element is as low as only {approx}2. Under high-power side diode pumping of a multiloop Nd:YAG laser, single-mode output radiation was achieved at {lambda} = 1.064 {mu}m with a pulse energy up to 0.75 J, a pulse repetition rate up to 25 Hz, an average power up to 18.3 W, and an efficiency up to 20%. In a multiloop Nd:YAG laser with three active elements in the cavity, single-mode radiation at {lambda} = 1.34 {mu}m was obtained with a pulse energy up to 0.96 J, a pulse repetition rate up to 10 Hz, and an average power up to 8.5 W. (control of laser radiation parameters)

  9. When your pain signifies my gain: neural activity while evaluating outcomes based on another person’s pain

    PubMed Central

    Cui, Fang; Zhu, Xiangru; Gu, Ruolei; Luo, Yue-jia

    2016-01-01

    The overlap between pain and reward processing pathways leds researchers to hypothesize that there are interactions between them in the human brain. Two hypotheses have been proposed. The “competition hypothesis” posits that reward can reduce pain-related neural activity and vice versa. The “salience hypothesis” suggests that the motivational salience of pain and reward can be mutually reinforced. However, no study has tested these two hypotheses from temporal perspective as we know. In the present study, pictures depicted other people in painful or non-painful situations were used to indicate the valence of outcomes in a gambling task. The event-related potential results revealed an interaction between another person’s pain and outcome valence in multiple time stages. Specifically, the amplitudes of the N1 and P3 were enhanced in the win condition compared with the loss condition when the outcome was indicated by painful picture. This interactions between pain and reward support the salience hypothesis but not the competition hypothesis. The present results provide evidence from human subjects that support the salience hypothesis, which claims that observing other people’s pain can enhance the salience of reward. PMID:27193060

  10. Inhibition of PRC2 Activity by a Gain-of-Function H3 Mutation Found in Pediatric Glioblastoma

    PubMed Central

    Lewis, Peter W.; Müller, Manuel M.; Koletsky, Matthew S.; Cordero, Francisco; Lin, Shu; Banaszynski, Laura A.; Garcia, Benjamin A.; Muir, Tom W.; Becher, Oren J.; Allis, C. David

    2014-01-01

    Sequencing of pediatric gliomas has identified missense mutations Lys27Met (K27M) and Gly34Arg/Val (G34R/V) in genes encoding histone H3.3 (H3F3A) and H3.1 (HIST3H1B). We report that human diffuse intrinsic pontine gliomas (DIPGs) containing the K27M mutation display significantly lower overall amounts of H3 with trimethylated lysine 27 (H3K27me3) and that histone H3K27M transgenes are sufficient to reduce the amounts of H3K27me3 in vitro and in vivo. We find that H3K27M inhibits the enzymatic activity of the Polycomb repressive complex 2 through interaction with the EZH2 subunit. In addition, transgenes containing lysine-to-methionine substitutions at other known methylated lysines (H3K9 and H3K36) are sufficient to cause specific reduction in methylation through inhibition of SET-domain enzymes. We propose that K-to-M substitutions may represent a mechanism to alter epigenetic states in a variety of pathologies. PMID:23539183

  11. Inhibition of PRC2 activity by a gain-of-function H3 mutation found in pediatric glioblastoma.

    PubMed

    Lewis, Peter W; Müller, Manuel M; Koletsky, Matthew S; Cordero, Francisco; Lin, Shu; Banaszynski, Laura A; Garcia, Benjamin A; Muir, Tom W; Becher, Oren J; Allis, C David

    2013-05-17

    Sequencing of pediatric gliomas has identified missense mutations Lys27Met (K27M) and Gly34Arg/Val (G34R/V) in genes encoding histone H3.3 (H3F3A) and H3.1 (HIST3H1B). We report that human diffuse intrinsic pontine gliomas (DIPGs) containing the K27M mutation display significantly lower overall amounts of H3 with trimethylated lysine 27 (H3K27me3) and that histone H3K27M transgenes are sufficient to reduce the amounts of H3K27me3 in vitro and in vivo. We find that H3K27M inhibits the enzymatic activity of the Polycomb repressive complex 2 through interaction with the EZH2 subunit. In addition, transgenes containing lysine-to-methionine substitutions at other known methylated lysines (H3K9 and H3K36) are sufficient to cause specific reduction in methylation through inhibition of SET-domain enzymes. We propose that K-to-M substitutions may represent a mechanism to alter epigenetic states in a variety of pathologies. PMID:23539183

  12. Production of medium-chain-length polyhydroxyalkanoates by activated sludge enriched under periodic feeding with nonanoic acid.

    PubMed

    Lee, Sun Hee; Kim, Jae Hee; Mishra, Debaraj; Ni, Yu-Yang; Rhee, Young Ha

    2011-05-01

    The potential use of activated sludge for the production of medium-chain-length polyhydroxyalkanoates (MCL-PHAs) was investigated. The enrichment of bacterial populations capable of producing MCL-PHAs was achieved by periodic feeding with nonanoic acid in a sequencing batch reactor (SBR). Denaturing gradient gel electrophoresis analysis revealed Pseudomonas aeruginosa strains to be predominant in the bacterial community during the SBR process. The composition of PHA synthesized by the enriched biomass from nonanoic acid consisted of a large concentration (>89 mol%) of MCL monomer units and a small amount of short-chain-length monomer units. Under fed-batch fermentation with continuous feeding of nonanoic acid at a flow rate of 0.225 g/L/h and a C/N ratio of 40, a maximum PHA content of 48.6% dry cell weight and a conversion yield (Y(p/s)) of 0.94 g/g were achieved. These results indicate that MCL-PHA production by activated sludge is a promising alternative to typical pure culture approaches. PMID:21463934

  13. Histone deacetylase inhibitors stimulate the susceptibility of A549 cells to a plasma-activated medium treatment.

    PubMed

    Adachi, Tetsuo; Kano, Ayame; Nonomura, Saho; Kamiya, Tetsuro; Hara, Hirokazu

    2016-09-15

    The number of potential applications of non-thermal atmospheric pressure plasma (NTAPP) discharges in medicine, particularly in cancer therapy, has increased in recent years. NTAPP has been shown to affect cells not only by direct irradiation, but also by an indirect treatment with previously prepared plasma-activated medium (PAM). Histone deacetylase (HDAC) inhibitors have the potential to enhance susceptibility to anticancer drugs and radiation. The aim of the present study was to demonstrate the advantage of the combined application of PAM and HDAC inhibitors on A549 cancer cell survival and elucidate the underlying mechanisms. Cell death with DNA breaks in the nucleus was greater using combined regimens of PAM and HDAC inhibitors such as trichostatin A (TSA) and valproic acid (VPA) than a single PAM treatment and was accompanied by the activation of poly (ADP-ribose) polymerase-1 (PARP-1), depletion of ATP, and elevations in intracellular calcium levels. Moreover, the expression of Rad 51, a DNA repair factor in homologous recombination pathways, was significantly suppressed by the treatment with HDAC inhibitors. These results demonstrate that HDAC inhibitors may synergistically induce the sensitivity of cancer cells to PAM components. PMID:27470189

  14. A Randomized Trial on the Effect of Bone Tissue on Vibration-induced Muscle Strength Gain and Vibration-induced Reflex Muscle Activity

    PubMed Central

    Cidem, Muharrem; Karacan, İlhan; Diraçoğlu, Demirhan; Yıldız, Aysel; Küçük, Suat Hayri; Uludağ, Murat; Gün, Kerem; Özkaya, Murat; Karamehmetoğlu, Şafak Sahir

    2014-01-01

    Background: Whole-body vibration (WBV) induces reflex muscle activity and leads to increased muscle strength. However, little is known about the physiological mechanisms underlying the effects of whole-body vibration on muscular performance. Tonic vibration reflex is the most commonly cited mechanism to explain the effects of whole-body vibration on muscular performance, although there is no conclusive evidence that tonic vibration reflex occurs. The bone myoregulation reflex is another neurological mechanism used to explain the effects of vibration on muscular performance. Bone myoregulation reflex is defined as a reflex mechanism in which osteocytes exposed to cyclic mechanical loading induce muscle activity. Aims: The aim of this study was to assess whether bone tissue affected vibration-induced reflex muscle activity and vibration-induced muscle strength gain. Study Design: A prospective, randomised, controlled, double-blind, parallel-group clinical trial. Methods: Thirty-four participants were randomised into two groups. High-magnitude whole-body vibration was applied in the exercise group, whereas low-magnitude whole-body vibration exercises were applied in the control group throughout 20 sessions. Hip bone mineral density, isokinetic muscle strength, and plasma sclerostin levels were measured. The surface electromyography data were processed to obtain the Root Mean Squares, which were normalised by maximal voluntarily contraction. Results: In the exercise group, muscle strength increased in the right and left knee flexors (23.9%, p=0.004 and 27.5%, p<0.0001, respectively). However, no significant change was observed in the knee extensor muscle strength. There was no significant change in the knee muscle strength in the control group. The vibration-induced corrected Root Mean Squares of the semitendinosus muscle was decreased by 2.8 times (p=0.005) in the exercise group, whereas there was no change in the control group. Sclerostin index was decreased by 15

  15. Promotion effect of manganese oxide on the electrocatalytic activity of Pt/C for methanol oxidation in acid medium

    NASA Astrophysics Data System (ADS)

    Abdel Hameed, R. M.; Fetohi, Amani E.; Amin, R. S.; El-Khatib, K. M.

    2015-12-01

    The modification of Pt/C by incorporating metal oxides for electrocatalytic oxidation of methanol has gained major attention because of the efficiency loss during the course of long-time operation. This work describes the preparation of Pt-MnO2/C electrocatalysts through a chemical route using ethylene glycol or a mixture of ethylene glycol and sodium borohydride as a reducing agent. The crystallite structure and particle size of synthesized electrocatalysts are determined using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The addition of MnO2 improves the dispersion of Pt nanoparticles. The electrocatalytic activity of Pt-MnO2/C towards methanol oxidation in H2SO4 solution is investigated using cyclic voltammetry and electrochemical impedance spectroscopy. The onset potential value of methanol oxidation peak is negatively shifted by 169 mV when MnO2 is introduced to Pt/C. Moreover, the charge transfer resistance value at Pt-MnO2/C is about 10 times as low as that at Pt/C. Chronoamperometry and chronopotentiometry show that CO tolerance is greatly improved at Pt-MnO2/C. The increased electrocatalytic activity and enhanced ability to clean platinum surface elect manganese oxide as a suitable promoter for the anode performance in direct methanol fuel cells (DMFCs).

  16. Somatic proembryo production from excised, wounded zygotic carrot embryos on hormone-free medium: evaluation of the effects of pH, ethylene and activated charcoal

    NASA Technical Reports Server (NTRS)

    Smith, D. L.; Krikorian, A. D.

    1990-01-01

    Wounded zygotic embryos of cultivated carrot produce somatic proembryos on hormone-free nutrient medium containing 1 mM NH4+ as the sole nitrogen source. Continued maintenance of proembryos on this medium leads to a "pure" culture of preglobular stage proembryos (PGSPs). Ethylene had no effect on this process. Also, somatic embryo production was not affected by growing cultures on activated charcoal-impregnated filter papers. However, somatic proembyros initiated on activated charcoal papers were not maintainable as PGSPs and developed into later embryo stages. Normally, medium pH dropped from 5.7 to 4 during each subculture period, but when using activated charcoal papers the pH endpoint was around 6 - 7 due to a leachable substance(s) within the filter papers. When powdered, activated charcoal was used in the medium as an adsorbent of products potentially released after wounding, pH dropped at the normal rate and to the expected levels; proembryos did not mature into later embryo stages and were maintainable exclusively as PGSPs. Low pH (approximately 4) is detrimental to proembyro production, but is essential to maintaining PGSPs on hormone-free nutrient medium, whereas a sustained pH > or = 5.7 allows continued development of PGSPs into later embryo stages.

  17. An infrared jet in Centaurus A (NGC 5128): Evidence for interaction between the active nucleus and the interstellar medium

    NASA Technical Reports Server (NTRS)

    Joy, Marshall; Harvey, P. M.; Tollestrup, E. V.; Mcgregor, P. J.; Hyland, A. R.

    1990-01-01

    In the present study, higher resolution near infrared images of the visually-obscured central region of Centaurus A were obtained in order to investigate the effects of the active nucleus on the surrounding galaxy. Researchers present J(1.25 microns), H(1.65 microns), and K(2.2 microns) images of the central 40 seconds of the galaxy, taken with the Univ. of Texas InSb array camera on the Anglo Australian 3.9 meter telescope. These images reveal a jet extending approx. 10 arcseconds to the northeast of the nucleus at the same position angle as the x ray and radio jets. The infrared jet is most prominent at the shortest wavelength (1.25 microns), where its brightness surpasses that of the nucleus. The blue appearance of the infrared jet is remarkable considering the heavy obscuration that is evident at visual wavelengths. The amount of reddening in the vicinity of the jet is determined from the measured colors of the stellar core of the galaxy, and this value is used to generate an extinction-corrected energy distribution. In contrast to previously studied optical and infrared jets in active nuclei, the short-wavelength prominence of the Cen A jet indicates that it cannot be attributed to synchrotron emission from a beam of relativistic electrons. The remaining viable mechanisms involve an interaction between the interstellar medium and the active nucleus: the infrared radiation from the jet may be due to emission from interstellar gas that has been entrained and heated by the flow of relativistic particles from the nucleus; alternatively, luminous blue stars may have been created by compression of interstellar material by the relativistic plasma. To investigate these proposed mechanisms, near-infrared spectroscopic studies of Cen A are in progress to look for collisionally excited molecular hydrogen emission lines and recombination lines from ionized gas.

  18. Visual Contrast Sensitivity Improvement by Right Frontal High-Beta Activity Is Mediated by Contrast Gain Mechanisms and Influenced by Fronto-Parietal White Matter Microstructure.

    PubMed

    Quentin, Romain; Elkin Frankston, Seth; Vernet, Marine; Toba, Monica N; Bartolomeo, Paolo; Chanes, Lorena; Valero-Cabré, Antoni

    2016-06-01

    Behavioral and electrophysiological studies in humans and non-human primates have correlated frontal high-beta activity with the orienting of endogenous attention and shown the ability of the latter function to modulate visual performance. We here combined rhythmic transcranial magnetic stimulation (TMS) and diffusion imaging to study the relation between frontal oscillatory activity and visual performance, and we associated these phenomena to a specific set of white matter pathways that in humans subtend attentional processes. High-beta rhythmic activity on the right frontal eye field (FEF) was induced with TMS and its causal effects on a contrast sensitivity function were recorded to explore its ability to improve visual detection performance across different stimulus contrast levels. Our results show that frequency-specific activity patterns engaged in the right FEF have the ability to induce a leftward shift of the psychometric function. This increase in visual performance across different levels of stimulus contrast is likely mediated by a contrast gain mechanism. Interestingly, microstructural measures of white matter connectivity suggest a strong implication of right fronto-parietal connectivity linking the FEF and the intraparietal sulcus in propagating high-beta rhythmic signals across brain networks and subtending top-down frontal influences on visual performance. PMID:25899709

  19. The Study of Electromagnetic Wave Propogation in Photonic Crystals Via Planewave Based Transfer (Scattering) Matrix Method with Active Gain Material Applications

    SciTech Connect

    Ming LI

    2007-12-01

    In this dissertation, a set of numerical simulation tools are developed under previous work to efficiently and accurately study one-dimensional (1D), two-dimensional(2D), 2D slab and three-dimensional (3D) photonic crystal structures and their defects effects by means of spectrum (transmission, reflection, absorption), band structure (dispersion relation), and electric and/or magnetic fields distribution (mode profiles). Furthermore, the lasing property and spontaneous emission behaviors are studied when active gain materials are presented in the photonic crystal structures. Various physical properties such as resonant cavity quality factor, waveguide loss, propagation group velocity of electromagnetic wave and light-current curve (for lasing devices) can be obtained from the developed software package.

  20. Investigation of selective induction of breast cancer cells to death with treatment of plasma-activated medium

    NASA Astrophysics Data System (ADS)

    Hashizume, Hiroshi; Tanaka, Hiromasa; Nakamura, Kae; Kano, Hiroyuki; Ishikawa, Kenji; Kikkawa, Fumitaka; Mizuno, Masaaki; Hori, Masaru

    2015-09-01

    The applications of plasma in medicine have much attention. We previously showed that plasma-activated medium (PAM) induced glioblastoma cells to apoptosis. However, it has not been elucidated the selectivity of PAM in detail. In this study, we investigated the selective effect of PAM on the death of human breast normal and cancer cells, MCF10A and MCF7, respectively, and observed the selective death with fluorescent microscopy. For the investigation of cell viability with PAM treatment, we prepared various PAMs according to the strengths, and treated each of cells with PAMs. Week PAM treatment only decreased the viability of MCF7 cells, while strong PAM treatment significantly affected both viabilities of MCF7 and MCF10A cells. For the fluorescent observation, we prepared the mixture of MCF7 and fluorescent-probed MCF10A cells, and seeded them. After the treatment of PAMs, the images showed that only MCF7 cells damaged in the mixture with week PAM treatment. These results suggested that a specific range existed with the selective effect in the strength of PAM. This work was partly supported by a Grant-in-Aid for Scientific Research on Innovative Areas ``Plasma Medical Innovation'' Grant No. 24108002 and 24108008 from the Ministry of Education, Culture, Sports, Science and Technology of Japan.

  1. Radioactively contaminated electric arc furnace dust as an addition to the immobilization mortar in low- and medium-activity repositories.

    PubMed

    Castellote, Marta; Menéndez, Esperanza; Andrade, Carmen; Zuloaga, Pablo; Navarro, Mariano; Ordóñez, Manuel

    2004-05-15

    Electric arc furnace dust (EAFD), generated by the steel-making industry, is in itself an intrinsic hazardous waste; however, the case may also be that scrap used in the process is accidentally contaminated by radioactive elements such as cesium. In this case the resulting EAFD is to be handled as radioactive waste, being duly confined in low- and medium-activity repositories (LMAR). What this paper studies is the reliability of using this radioactive EAFD as an addition in the immobilization mortar of the containers of the LMAR, that is, from the point of view of the durability. Different mixes of mortar containing different percentages of EAFD have been subjected to flexural and compressive strength, initial and final setting time, XRD study, total porosity and pore size distribution, determination of the chloride diffusion coefficient, dimensional stability tests, hydration heat, workability of the fresh mix, and leaching behavior. What is deduced from the results is that for the conditions used in this research, (cement + sand) can be replaced by EAFD upto a ratio [EAFD/(cement + EAFD)] of 46% in the immobilization mortar of LMAR, apparently without any loss in the long-term durability properties of the mortar. PMID:15212272

  2. Antimicrobial Activity of Xoconostle Pears (Opuntia matudae) against Escherichia coli O157:H7 in Laboratory Medium

    PubMed Central

    Hayek, Saeed A.; Ibrahim, Salam A.

    2012-01-01

    The objective of this study was to investigate the antimicrobial activity of xoconostle pears (Opuntia matudae) against Escherichia coli O157:H7. Xoconostle pears were sliced, blended, and centrifuged. The supernatant was then filtered using a 0.45 μm filter to obtain direct extract. Direct extract of xoconostle pears was tested against four strains of E. coli O157:H7 in brain heart infusion (BHI) laboratory medium using growth over time and agar well diffusion assays. Our results showed that direct extract of xoconostle pears had a significant (P < 0.05) inhibitory effect at 4, 6, and 8% (v/v) concentrations and complete inhibitory effect at 10% (v/v) during 8 h of incubation at 37°C. Minimum inhibitory volume (MIV) was 400 μL mL−1 (v/v) and minimum lethal volume (MLV) was 650 μL mL−1 (v/v). The inhibitory effect of xoconostle pears found to be concentration dependent and not strain dependent. Thus, xoconostle pears extract has the potential to inhibit the growth of E. coli O157:H7 and could provide a natural means of controlling pathogenic contamination, thereby mitigating food safety risks. PMID:22934117

  3. Effect of temperature, pH, and water activity on Mucor spp. growth on synthetic medium, cheese analog and cheese.

    PubMed

    Morin-Sardin, Stéphanie; Rigalma, Karim; Coroller, Louis; Jany, Jean-Luc; Coton, Emmanuel

    2016-06-01

    The Mucor genus includes a large number of ubiquitous fungal species. In the dairy environment, some of them play a technological role providing typical organoleptic qualities to some cheeses while others can cause spoilage. In this study, we compared the effect of relevant abiotic factors for cheese production on the growth of six strains representative of dairy technological and contaminant species as well as of a non cheese related strain (plant endophyte). Growth kinetics were determined for each strain in function of temperature, water activity and pH on synthetic Potato Dextrose Agar (PDA), and secondary models were fitted to calculate the corresponding specific cardinal values. Using these values and growth kinetics acquired at 15 °C on cheese agar medium (CA) along with three different cheese types, optimal growth rates (μopt) were estimated and consequently used to establish a predictive model. Contrarily to contaminant strains, technological strains showed higher μopt on cheese matrices than on PDA. Interestingly, lag times of the endophyte strain were strongly extended on cheese related matrices. This study offers a relevant predictive model of growth that may be used for better cheese production control but also raises the question of adaptation of some Mucor strains to the cheese. PMID:26919819

  4. Plasma-activated medium suppresses choroidal neovascularization in mice: a new therapeutic concept for age-related macular degeneration.

    PubMed

    Ye, Fuxiang; Kaneko, Hiroki; Nagasaka, Yosuke; Ijima, Ryo; Nakamura, Kae; Nagaya, Masatoshi; Takayama, Kei; Kajiyama, Hiroaki; Senga, Takeshi; Tanaka, Hiromasa; Mizuno, Masaaki; Kikkawa, Fumitaka; Hori, Masaru; Terasaki, Hiroko

    2015-01-01

    Choroidal neovascularization (CNV) is the main pathogenesis of age-related macular degeneration (AMD), which leads to severe vision loss in many aged patients in most advanced country. CNV compromises vision via hemorrhage and retinal detachment on account of pathological neovascularization penetrating the retina. Plasma medicine represents the medical application of ionized gas "plasma" that is typically studied in the field of physical science. Here we examined the therapeutic ability of plasma-activated medium (PAM) to suppress CNV. The effect of PAM on vascularization was assessed on the basis of human retinal endothelial cell (HREC) tube formation. In mice, laser photocoagulation was performed to induce CNV (laser-CNV), followed by intravitreal injection of PAM. N-Acetylcysteine was used to examine the role of reactive oxygen species in PAM-induced CNV suppression. Fundus imaging, retinal histology examination, and electroretinography (ERG) were also performed to evaluate PAM-induced retinal toxicity. Interestingly, HREC tube formation and laser-CNV were both reduced by treatment with PAM. N-acetylcysteine only partly neutralized the PAM-induced reduction in laser-CNV. In addition, PAM injection had no effect on regular retinal vessels, nor did it show retinal toxicity in vivo. Our findings indicate the potential of PAM as a novel therapeutic agent for suppressing CNV. PMID:25573059

  5. Plasma-activated medium suppresses choroidal neovascularization in mice: a new therapeutic concept for age-related macular degeneration

    PubMed Central

    Ye, Fuxiang; Kaneko, Hiroki; Nagasaka, Yosuke; Ijima, Ryo; Nakamura, Kae; Nagaya, Masatoshi; Takayama, Kei; Kajiyama, Hiroaki; Senga, Takeshi; Tanaka, Hiromasa; Mizuno, Masaaki; Kikkawa, Fumitaka; Hori, Masaru; Terasaki, Hiroko

    2015-01-01

    Choroidal neovascularization (CNV) is the main pathogenesis of age-related macular degeneration (AMD), which leads to severe vision loss in many aged patients in most advanced country. CNV compromises vision via hemorrhage and retinal detachment on account of pathological neovascularization penetrating the retina. Plasma medicine represents the medical application of ionized gas “plasma” that is typically studied in the field of physical science. Here we examined the therapeutic ability of plasma-activated medium (PAM) to suppress CNV. The effect of PAM on vascularization was assessed on the basis of human retinal endothelial cell (HREC) tube formation. In mice, laser photocoagulation was performed to induce CNV (laser-CNV), followed by intravitreal injection of PAM. N-Acetylcysteine was used to examine the role of reactive oxygen species in PAM-induced CNV suppression. Fundus imaging, retinal histology examination, and electroretinography (ERG) were also performed to evaluate PAM-induced retinal toxicity. Interestingly, HREC tube formation and laser-CNV were both reduced by treatment with PAM. N-acetylcysteine only partly neutralized the PAM-induced reduction in laser-CNV. In addition, PAM injection had no effect on regular retinal vessels, nor did it show retinal toxicity in vivo. Our findings indicate the potential of PAM as a novel therapeutic agent for suppressing CNV. PMID:25573059

  6. Symbiotic starburst-black hole active galactic nuclei - I. Isothermal hydrodynamics of the mass-loaded interstellar medium

    NASA Astrophysics Data System (ADS)

    Williams, R. J. R.; Baker, A. C.; Perry, Judith J.

    1999-12-01

    Compelling evidence associates the nuclei of active galaxies and massive starbursts. The symbiosis between a compact nuclear starburst stellar cluster and a massive black hole can self-consistently explain the properties of active nuclei. The young stellar cluster has a profound effect on the most important observable properties of active galaxies through its gravity, and by mass injection through stellar winds, supernovae and stellar collisions. This mass loss, injected throughout the nucleus, creates a hot nuclear interstellar medium (nISM). The cluster both acts as an optically thin fuel reservoir and enriches the nISM with the products of nucleosynthesis. The nISM flows under gravitational and radiative forces until it leaves the nucleus or is accreted on to the black hole or accretion disc. The radiative force exerted by the black hole-accretion disc radiation field is not spherically symmetric. This results in complex flows in which regions of inflow can coexist with high Mach number outflowing winds and hydrodynamic jets. We present two-dimensional hydrodynamic models of such nISM flows, which are highly complex and time-variable. Shocked shells, jets and explosive bubbles are produced, with bipolar winds driving out from the nucleus. Our results graphically illustrate why broad-emission-line studies have consistently failed to identify any simple, global flow geometry. The real structure of the flows is inevitably yet more complex. The structure of these nISM flows is principally determined by two dimensionless quantities. The first is the magnitude of the stellar cluster velocity dispersion relative to the sound speed in the nISM. These speeds measure the gravitational and thermal energies in the nISM respectively, and, therefore, whether the gas is initially bound or escapes in a thermal wind. The second parameter is the Mach number of the ill-collimated nISM flow which is driven away from the central black hole. We discuss a two-parameter classification

  7. Global expression profiling reveals gain-of-function onco-genic activity of a mutated thyroid hormone receptor in thyroid carcinogenesis

    PubMed Central

    Lu, Changxue; Mishra, Alok; Zhu, Yuelin J; Meltzer, Paul; Cheng, Sheue-yann

    2011-01-01

    Thyroid hormone receptors (TRs) are critical in regulating gene expression in normal physiological processes. Decreased expression and/or somatic mutations of TRs have been shown to be associated several types of human cancers including liver, breast, lung, and thyroid. To understand the molecular mechanisms by which mutated TRs promote carcinogenesis, an animal model of follicular thyroid carcinoma (FTC) (Thrbpv/pv mice) was used in the present study. The Thrbpv/pv mouse harbors a knockin dominant negative PV mutation, identified in a patient with resistance to thyroid hormone. To understand whether oncogenic actions of PV involve not only the loss of normal TR functions but also gain-of-function activities, we compared the gene expression profiles of thyroid lesions in Thrbpv/pv mice and Thra1-/- Thrb-/- mice that also spontaneously develop FTC, but with less severe malignancy. Analysis of the cDNA microarray data derived from microdissected thyroid tumor cells of these two mice showed contrasting global gene expression profiles. With stringent selection using 2.5-fold change (p<0.01) in cDNA microarray analysis, 241 genes with altered gene expression were identified. Nearly half of the genes (n=103: 42.7% of total) with altered gene expression in thyroid tumor cells of Thrbpv/pv mice were associated with tumorigenesis and metastasis; some of these genes function as oncogenes in human thyroid cancers. The remaining genes were found to function in transcriptional regulation, RNA processing, cell proliferation, apoptosis, angiogenesis, and cytoskeleton modification. These results indicate that the more aggressive thyroid tumor progression in Thrbpv/pv mice was not due simply to the loss of tumor suppressor functions of TR via mutation but also, importantly, to gain-of-function in the oncogenic activities of PV to drive thyroid carcinogenesis. Thus, the present study identifies a novel mechanism by which a mutated TRβ evolves with an oncogenic advantage to promote

  8. DNA polymorphisms and transcript abundance of PRKAG2 and phosphorylated AMP-activated protein kinase in the rumen are associated with gain and feed intake in beef steers.

    PubMed

    Lindholm-Perry, A K; Kuehn, L A; Oliver, W T; Kern, R J; Cushman, R A; Miles, J R; McNeel, A K; Freetly, H C

    2014-08-01

    Beef steers with variation in feed efficiency phenotypes were evaluated previously on a high-density SNP panel. Ten markers from rs110125325-rs41652818 on bovine chromosome 4 were associated with average daily gain (ADG). To identify the gene(s) in this 1.2-Mb region responsible for variation in ADG, genotyping with 157 additional markers was performed. Several markers (n = 41) were nominally associated with ADG, and three of these, including the only marker to withstand Bonferroni correction, were located within the protein kinase, AMP-activated, gamma 2 non-catalytic subunit (PRKAG2) gene. An additional population of cross-bred steers (n = 406) was genotyped for validation. One marker located within the PRKAG2 loci approached a significant association with gain. To evaluate PRKAG2 for differences in transcript abundance, we measured expression in the liver, muscle, rumen and intestine from steers (n = 32) with extreme feed efficiency phenotypes collected over two seasons. No differences in PRKAG2 transcript abundance were detected in small intestine, liver or muscle. Correlation between gene expression level of PRKAG2 in rumen and average daily feed intake (ADFI) was detected in both seasons (P < 0.05); however, the direction differed by season. Lastly, we evaluated AMP-activated protein kinase (AMPK), of which PRKAG2 is a subunit, for differences among ADG and ADFI and found that the phosphorylated form of AMPK was associated with ADFI in the rumen. These data suggest that PRKAG2 and its mature protein, AMPK, are involved in feed efficiency traits in beef steers. This is the first evidence to suggest that rumen AMPK may be contributing to ADFI in cattle. PMID:24730749

  9. Random lasing with spatially nonuniform gain

    NASA Astrophysics Data System (ADS)

    Fan, Ting; Lü, Jiantao

    2016-07-01

    Spatial and spectral properties of random lasing with spatially nonuniform gain were investigated in two-dimensional (2D) disordered medium. The pumping light was described by an individual electric field and coupled into the rate equations by using the polarization equation. The spatially nonuniform gain comes from the multiple scattering of this pumping light. Numerical simulation of the random system with uniform and nonuniform gain were performed both in weak and strong scattering regime. In weak scattering sample, all the lasing modes correspond to those of the passive system whether the nonuniform gain is considered. However, in strong scattering regime, new lasing modes appear with nonuniform gain as the localization area changes. Our results show that it is more accurate to describe the random lasing behavior with introducing the nonuniform gain origins from the multiple light scattering.

  10. Characterization of active fault scarps from medium to high resolution DEM: case studies from Central and Southern Apennines (Italy)

    NASA Astrophysics Data System (ADS)

    Brunori, C.; Cinti, F. R.; Ventura, G.

    2013-12-01

    We identify geo-morphometric features of active fault scarps in Italy through a semiautomatic processing using GIS. Medium to high resolution DEM was used to characterize the geometry, structural, and erosive elements of two seismogenic normal faults in Central and Southern Apennines. The Pettino fault in L'Aquila area was detected using a 1 m pixel DEM derived from airborne LiDAR survey (Friuli Venezia Giulia Civil Protection). For the Castrovillari fault in northern Calabria region was used a 4 m pixel DEM (Regional Cartography Office of Regione Calabria). Scarp segments are region of planar discontinuities identified by selected values of DEM-derived Terrain Ruggedness Index (TRI) and Vector Ruggedness Measure (VRM). These planar discontinuities corresponds to landscape features such as, river terraces, roads scarps, and other natural or human features. The discrimination between these features have been accomplished overlaying extracted features on aerial photograph, geological and geomorphologic maps and in situ survey. After that, we perform the quantitative and statistical analysis of these areas identified as "fault scarps". The identification of elements relative to the scarps (e.g. base, crest, slope) is then obtained to derive the estimate of parameters describing the fault: altitude, height of the scarp, length, slope and aspect, Terrain Ruggedness Index (TRI) and Vector Ruggedness Measure (VRM). The spatial distribution of the extracted values was obtained through their statistical analysis. We analyze scarp parameters variations along the whole scarp extent, such as strike value from aspect variations, slope and profile curvature differences as indicators of tectonic and/or erosion activity. The combined analysis of the DEM-derived parameters allows us to (a) define aspects of three-dimensional scarp geometry, (b) decipher its geomorphological significance, and (c) estimate the long-term slip rate.

  11. Use of a photonic crystal for optical amplifier gain control

    DOEpatents

    Lin, Shawn-Yu; Fleming, James G.; El-Kady, Ihab

    2006-07-18

    An optical amplifier having a uniform gain profile uses a photonic crystal to tune the density-of-states of a gain medium so as to modify the light emission rate between atomic states. The density-of-states of the gain medium is tuned by selecting the size, shape, dielectric constant, and spacing of a plurality of microcavity defects in the photonic crystal. The optical amplifier is particularly useful for the regeneration of DWDM signals in long optical fibers.

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

    NASA Astrophysics Data System (ADS)

    Li, Ming

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

  13. Dossier on Completed and Ongoing Activities in the Field of "Small and Medium-Sized Enterprises." (First Review 1986-1990).

    ERIC Educational Resources Information Center

    Melis, A.

    1991-01-01

    The European Centre for the Development of Vocational Training's (CEDEFOP) activities and research relating to small and medium-sized enterprises (SMEs) have focused on three areas of action: (1) development of training for SMEs; (2) information on the training provision available in the member states; and (3) promotion of the exchange and…

  14. Evaluation of the Effects of the Medium of Instruction on Science Learning of Hong Kong Secondary Students: Instructional Activities in Science Lessons

    ERIC Educational Resources Information Center

    Yip, Din-Yan; Coyle, Do; Tsang, Wing-Kwong

    2007-01-01

    This article reports part of the findings of a longitudinal study on the effects of a language policy implemented in 1998 on the science learning of junior secondary students. It focuses on the effects of the instructional medium on the instructional activities in science lessons. According to students' responses to a questionnaire, EMI (English…

  15. Gain-of-Function Mutations in the Toll-Like Receptor Pathway: TPL2-Mediated ERK1/ERK2 MAPK Activation, a Path to Tumorigenesis in Lymphoid Neoplasms?

    PubMed Central

    Rousseau, Simon; Martel, Guy

    2016-01-01

    Lymphoid neoplasms form a family of cancers affecting B-cells, T-cells, and NK cells. The Toll-Like Receptor (TLR) signaling adapter molecule MYD88 is the most frequently mutated gene in these neoplasms. This signaling adaptor relays signals from TLRs to downstream effector pathways such as the Nuclear Factor kappa B (NFκB) and Mitogen Activated Protein Kinase (MAPK) pathways to regulate innate immune responses. Gain-of-function mutations such as MYD88[L265P] activate downstream signaling pathways in absence of cognate ligands for TLRs, resulting in increased cellular proliferation and survival. This article reports an analysis of non-synonymous somatic mutations found in the TLR signaling network in lymphoid neoplasms. In accordance with previous reports, mutations map to MYD88 pro-inflammatory signaling and not TRIF-mediated Type I IFN production. Interestingly, the analysis of somatic mutations found downstream of the core TLR-signaling network uncovered a strong association with the ERK1/2 MAPK cascade. In support of this analysis, heterologous expression of MYD88[L265P] in HEK293 cells led to ERK1/2 MAPK phosphorylation in addition to NFκB activation. Moreover, this activation is dependent on the protein kinase Tumor Promoting Locus 2 (TPL2), activated downstream of the IKK complex. Activation of ERK1/2 would then lead to activation, amongst others, of MYC and hnRNPA1, two proteins previously shown to contribute to tumor formation in lymphoid neoplasms. Taken together, this analysis suggests that TLR-mediated ERK1/2 activation via TPL2 may be a novel path to tumorigenesis. Therefore, the hypothesis proposed is that inhibition of ERK1/2 MAPK activation would prevent tumor growth downstream of MYD88[L265]. It will be interesting to test whether pharmacological inhibitors of this pathway show efficacy in primary tumor cells derived from hematologic malignancies such as Waldenstrom's Macroglobulinemia, where the majority of the cells carry the MYD88[L265P

  16. Differential sensitivity of medium- and large-sized striatal neurons to NMDA but not kainate receptor activation in the rat.

    PubMed

    Cepeda, C; Itri, J N; Flores-Hernández, J; Hurst, R S; Calvert, C R; Levine, M S

    2001-11-01

    Infrared videomicroscopy and differential interference contrast optics were used to identify medium- and large-sized neurons in striatal slices from young rats. Whole-cell patch-clamp recordings were obtained to compare membrane currents evoked by application of N-methyl-d-aspartate (NMDA) and kainate. Inward currents and current densities induced by NMDA were significantly smaller in large- than in medium-sized striatal neurons. The negative slope conductance for NMDA currents was greater in medium- than in large-sized neurons and more depolarization was required to remove the Mg2+ blockade. In contrast, currents induced by kainate were significantly greater in large-sized neurons whilst current densities were approximately equal in both cell types. Spontaneous excitatory postsynaptic currents occurred frequently in medium-sized neurons but were relatively infrequent in large-sized neurons. Excitatory postsynaptic currents evoked by electrical stimulation were smaller in large- than in medium-sized neurons. A final set of experiments assessed a functional consequence of the differential sensitivity of medium- and large-sized neurons to NMDA. Cell swelling was used to examine changes in somatic area in both neuronal types after prolonged application of NMDA or kainate. NMDA produced a time-dependent increase in somatic area in medium-sized neurons whilst it produced only minimal changes in large interneurons. In contrast, application of kainate produced significant swelling in both medium- and large-sized cells. We hypothesize that reduced sensitivity to NMDA may be due to variations in receptor subunit composition and/or the relative density of receptors in the two cell types. These findings help define the conditions that put neurons at risk for excitotoxic damage in neurological disorders. PMID:11860453

  17. Giant Raman gain in silicon nanocrystals

    PubMed Central

    Sirleto, Luigi; Antonietta Ferrara, Maria; Nikitin, Timur; Novikov, Sergei; Khriachtchev, Leonid

    2012-01-01

    Nanostructured silicon has generated a lot of interest in the past decades as a key material for silicon-based photonics. The low absorption coefficient makes silicon nanocrystals attractive as an active medium in waveguide structures, and their third-order nonlinear optical properties are crucial for the development of next generation nonlinear photonic devices. Here we report the first observation of stimulated Raman scattering in silicon nanocrystals embedded in a silica matrix under non-resonant excitation at infrared wavelengths (~1.5 μm). Raman gain is directly measured as a function of the silicon content. A giant Raman gain from the silicon nanocrystals is obtained that is up to four orders of magnitude greater than in crystalline silicon. These results demonstrate the first Raman amplifier based on silicon nanocrystals in a silica matrix, thus opening new perspectives for the realization of more efficient Raman lasers with ultra-small sizes, which would increase the synergy between electronic and photonic devices. PMID:23187620

  18. Effect of temperature and water activity on gene expression and aflatoxin biosynthesis in Aspergillus flavus on almond medium.

    PubMed

    Gallo, Antonia; Solfrizzo, Michele; Epifani, Filomena; Panzarini, Giuseppe; Perrone, Giancarlo

    2016-01-18

    Almonds are among the commodities at risk of aflatoxin contamination by Aspergillus flavus. Temperature and water activity are the two key determinants in pre and post-harvest environments influencing both the rate of fungal spoilage and aflatoxin production. Varying the combination of these parameters can completely inhibit or fully activate the biosynthesis of aflatoxin, so it is fundamental to know which combinations can control or be conducive to aflatoxin contamination. Little information is available about the influence of these parameters on aflatoxin production on almonds. The objective of this study was to determine the influence of different combinations of temperature (20 °C, 28 °C, and 37 °C) and water activity (0.90, 0.93, 0.96, 0.99 aw) on growth, aflatoxin B1 (AFB1) production and expression of the two regulatory genes, aflR and aflS, and two structural genes, aflD and aflO, of the aflatoxin biosynthetic cluster in A. flavus grown on an almond medium solidified with agar. Maximum accumulation of fungal biomass and AFB1 production was obtained at 28 °C and 0.96 aw; no fungal growth and AFB1 production were observed at 20 °C at the driest tested conditions (0.90 and 0.93 aw). At 20° and 37 °C AFB1 production was 70-90% lower or completely suppressed, depending on aw. Reverse transcriptase quantitative PCR showed that the two regulatory genes (aflR and aflS) were highly expressed at maximum (28 °C) and minimum (20 °C and 37 °C) AFB1 production. Conversely the two structural genes (aflD and aflO) were highly expressed only at maximum AFB1 production (28 °C and 0.96-0.99 aw). It seems that temperature acts as a key factor influencing aflatoxin production which is strictly correlated to the induction of expression of structural biosynthesis genes (aflD and aflO), but not to that of aflatoxin regulatory genes (aflR and aflS), whose functional products are most likely subordinated to other regulatory processes acting at post-translational level

  19. Effects of preincubation of eggs and activation medium on the percentage of eyed embryos in ide (Leuciscus idus), an externally fertilizing fish.

    PubMed

    Siddique, Mohammad Abdul Momin; Linhart, Otomar; Krejszeff, Sławomir; Żarski, Daniel; Król, Jarosław; Butts, Ian Anthony Ernest

    2016-03-15

    Standardization of fertilization protocols is crucial for improving reproductive techniques for externally fertilizing fish in captive breeding. Therefore, the objectives of this study were to determine the effects of preincubation of eggs and activation medium on the percentage of eyed embryos for ide (Leuciscus idus). Pooled eggs from five females were preincubated in three different activating media for 0, 30, 60, 90, and 120 seconds and then fertilized by pooled sperm from five males. At the eyed-egg stage, the percentage of viable embryos was later calculated. Results showed that preincubation time was significant for the freshwater activation medium (P < 0.001), such that the percentage of eyed embryos declined across the preincubation time gradient. Additionally, there was an effect on the percentage of eyed embryos when eggs were incubated with Woynarovich solution (P < 0.001), such that a decline was detected at 90 seconds, whereas no effect was detected for the saline water medium. Activating medium had a significant effect on the percentage of eyed embryos for each preincubation time (P < 0.05). More precisely, freshwater produced the lowest percentage of eyed embryos at all preincubation times (ranged from 1.9% at 120 seconds to 43.6% at 0 seconds), whereas saline water and Woynarovich solution produced the highest percentage of eyed embryos at 0 seconds and 30 seconds before incubation. Woynarovich solution produced the highest percentage of eyed embryos at 60 seconds (65.26%), whereas saline water produced the highest percentage at 90 seconds (68.37%). No difference was detected between saline water and Woynarovich solution at 120 seconds. Examination of sperm traits showed no impact of activating medium on computer assisted sperm analysis parameters. Together, these results suggest that saline water or Woynarovich solution improve fertilization rate in ide during IVF; thus, these media are useful for standardizing fertilization protocols and

  20. DRIVING OUTFLOWS WITH RELATIVISTIC JETS AND THE DEPENDENCE OF ACTIVE GALACTIC NUCLEUS FEEDBACK EFFICIENCY ON INTERSTELLAR MEDIUM INHOMOGENEITY

    SciTech Connect

    Wagner, A. Y.; Umemura, M.; Bicknell, G. V.

    2012-10-01

    We examine the detailed physics of the feedback mechanism by relativistic active galactic nucleus (AGN) jets interacting with a two-phase fractal interstellar medium (ISM) in the kpc-scale core of galaxies using 29 three-dimensional grid-based hydrodynamical simulations. The feedback efficiency, as measured by the amount of cloud dispersal generated by the jet-ISM interactions, is sensitive to the maximum size of clouds in the fractal cloud distribution but not to their volume filling factor. Feedback ceases to be efficient for Eddington ratios P{sub jet}/L{sub edd} {approx}< 10{sup -4}, although systems with large cloud complexes {approx}> 50 pc require jets of Eddington ratio in excess of 10{sup -2} to disperse the clouds appreciably. Based on measurements of the bubble expansion rates in our simulations, we argue that sub-grid AGN prescriptions resulting in negative feedback in cosmological simulations without a multi-phase treatment of the ISM are good approximations if the volume filling factor of warm-phase material is less than 0.1 and the cloud complexes are smaller than {approx}25 pc. We find that the acceleration of the dense embedded clouds is provided by the ram pressure of the high-velocity flow through the porous channels of the warm phase, flow that has fully entrained the shocked hot-phase gas it has swept up, and is additionally mass loaded by ablated cloud material. This mechanism transfers 10% to 40% of the jet energy to the cold and warm gas, accelerating it within a few 10 to 100 Myr to velocities that match those observed in a range of high- and low-redshift radio galaxies hosting powerful radio jets.

  1. Galactic cosmic ray modulation and interplanetary medium perturbations due to a long-living active region during October 1989

    NASA Technical Reports Server (NTRS)

    Bavassano, B.; Iucci, N.; Lepping, R. P.; Signorini, C.; Smith, E. J.; Villoresi, G.

    1994-01-01

    During October 1989, three very energetic flares were ejected by the same active region at longitudes 9 deg E, 32 deg W, and 57 deg W, respectively. The shape of the galactic cosmic ray variations suggests the presence of large magnetic cloud structures (Nagashima et al., 1990) following the shock-associated perturbations. In spite of long data gaps the interplanetary observations at Interplanetary Monitoring Platform (IMP) 8 (near the Earth) and International Cometary Explorer (ICE)(approximately 1 AU, approximately 65 deg W) confirm this possibility for the event related to the 9 deg E flare; the principal axes analysis shows that the interplanetary magnetic field variations at both spacecraft locations are mainly confined on a meridian plane. This result suggests that the western longitudinal extension of this cloud is indeed very large (greater than or equal to 5 deg). The nonnegligible depression in the cosmic ray intensity observed inside the possible cloud related to the 57 deg W flare indicates that also the eastern extension could be very wide. The analysis of neutron monitor data shows clearly the cosmic ray trapping effect of magnetic clouds; this mechanism seems to be responsible for the enhanced diurnal effect often observed during the recovery phase of Forbush decreases. We give an interpretation for the anisotropic cosmic ray peak occurring in the third event, and, related to that, we suggest that the Forbush decrease modulated region at the Earth's orbit could be somewhat wider than the magnetic cloud, as already anticipated by Nagashima et al. (1990). By this analysis, based mainly on cosmic ray data, we show that it is possible to do reasonable inferences on the large-scale structure of flare-related interplanetary perturbations when interplanetary medium data are not completely present.

  2. Acting to gain information

    NASA Technical Reports Server (NTRS)

    Rosenchein, Stanley J.; Burns, J. Brian; Chapman, David; Kaelbling, Leslie P.; Kahn, Philip; Nishihara, H. Keith; Turk, Matthew

    1993-01-01

    This report is concerned with agents that act to gain information. In previous work, we developed agent models combining qualitative modeling with real-time control. That work, however, focused primarily on actions that affect physical states of the environment. The current study extends that work by explicitly considering problems of active information-gathering and by exploring specialized aspects of information-gathering in computational perception, learning, and language. In our theoretical investigations, we analyzed agents into their perceptual and action components and identified these with elements of a state-machine model of control. The mathematical properties of each was developed in isolation and interactions were then studied. We considered the complexity dimension and the uncertainty dimension and related these to intelligent-agent design issues. We also explored active information gathering in visual processing. Working within the active vision paradigm, we developed a concept of 'minimal meaningful measurements' suitable for demand-driven vision. We then developed and tested an architecture for ongoing recognition and interpretation of visual information. In the area of information gathering through learning, we explored techniques for coping with combinatorial complexity. We also explored information gathering through explicit linguistic action by considering the nature of conversational rules, coordination, and situated communication behavior.

  3. Differentiation of purified astrocytes in a chemically defined medium

    SciTech Connect

    Morrison, R.S.; de Vellis, J.

    1981-01-01

    Homogeneous cultures of astrocytes and oligodendrocytes provide an excellent model system for studying the regulation of glial structure and function. Recently, a chemically defined (CD) medium was developed for purified cultures of astrocytes, thus eliminating the requirement for serum and providing a controlled system for the study of astroglial properties. Due to the widespread use of astrocyte cultures and the potential benefits to be gained from using a defined medium, astrocyte cultures raised in CD medium were analyzed for purity as well as morphological and biochemical properties. Purity was assessed using immunocytochemical staining for glial fibrillary acidic protein (GFAP) and fibronectin. Astrocytes raised in CD medium are 95% pure using the expression of GFAP as a criterion. Fewer than 1% of the cells in CD medium stained positive for fibronectin eliminating the possibility that CD medium is selective for meningeal or endothelial cells. Astrocytes raised in CD medium exhibit a striking degree of morphological differentiation as seen in scanning electron micrographs. They also exhibit a high degree of biochemical differentiation illustrated by increases in the specific activity of S-100 protein and the induction of glutamine synthetase by glucocorticoids. A defined medium that supports the proliferation of rat astrocytes and enhances numerous morphological and biochemical properties should greatly facilitate the study of factors controlling glial proliferation and differentiation.

  4. Dissociation and regeneration kinetics of carbon dioxide in the active medium of sealed-off transverse RF-excited CO{sub 2} lasers

    SciTech Connect

    Vesnov, I G

    2010-06-23

    An improved mathematical model describing the dissociation and regenerations kinetics of carbon dioxide in the active medium of sealed-off transverse RF-excited CO{sub 2} lasers is presented. It is shown that the calculation of the active medium composition of such lasers requires the equations of the gas-mixture kinetics to take into account the diffuse flow of oxygen atoms on metal electrodes and on the surface of heterogeneous catalysts used to reduce the degree of the carbon dioxide dissociation. The rate constants of the heterogeneous recombination reaction CO + O {yields} CO{sub 2} on the surface of alumina ceramics and Al{sub 2}O{sub 3} are determined. (active media)

  5. Gain weighted eigenspace assignment

    NASA Technical Reports Server (NTRS)

    Davidson, John B.; Andrisani, Dominick, II

    1994-01-01

    This report presents the development of the gain weighted eigenspace assignment methodology. This provides a designer with a systematic methodology for trading off eigenvector placement versus gain magnitudes, while still maintaining desired closed-loop eigenvalue locations. This is accomplished by forming a cost function composed of a scalar measure of error between desired and achievable eigenvectors and a scalar measure of gain magnitude, determining analytical expressions for the gradients, and solving for the optimal solution by numerical iteration. For this development the scalar measure of gain magnitude is chosen to be a weighted sum of the squares of all the individual elements of the feedback gain matrix. An example is presented to demonstrate the method. In this example, solutions yielding achievable eigenvectors close to the desired eigenvectors are obtained with significant reductions in gain magnitude compared to a solution obtained using a previously developed eigenspace (eigenstructure) assignment method.

  6. Coupling hydrologic and hydraulic modelling for reliable flood risk mitigation activities in the Upper-Medium Tiber River basin

    NASA Astrophysics Data System (ADS)

    Berni, N.; Brocca, L.; Giustarini, L.; Pandolfo, C.; Stelluti, M.; Melone, F.; Moramarco, T.

    2009-04-01

    In view of the recent and serious flood events occurred in latest years in Italy, the interest towards accurate methodology for the evaluation of flood prone areas is continually increasing. In particular, this issue is related to urbanization planning activities, civil protection actions (e.g. hydraulic risk warning systems), and the assessment of hydraulic engineering structures behaviour during severe hydrometeorological conditions. In Italy, following the publishing in the late 90's of many laws and regulations concerning hydraulic risk assessment matters, a widespread flooding areas mapping have been carried out (Italian Basin Authorities "PAI" plans). In case of limited availability of historical peak flow data, the flood prone areas estimation was based on the application of hydrologic and hydraulic modelling separately. Moreover, the recent directive 2007/60/EC on the assessment and management of flood risks requires from each member state: preliminary flood risk assessment (within December 2011), flood hazard maps and flood risk maps (within December 2013), flood risk management plans (within December 2015). In order to prevent and control flood events in medium-small river basins (e.g. Upper Tiber River basin, Central Italy), the use of hydrologic models coupled with hydraulic ones can be a valuable tool also for real time applications, such as flood risk mitigation and warning activities of the Italian National Warning System Network (composed by regional "Functional Centres" coordinated by the National Civil Protection Department). In this context, two significant flood events occurred in November 2005 and December 2008 in the Umbria Region territory were considered. In this area a hydrometeorological network, characterized by a high temporal and spatial resolution, is operating in real time. Different coupled models were considered to reproduce the selected events, in order to test and compare their reliability and efficiency. Specifically, two semi

  7. A single amino acid substitution in a chitinase of the legume Medicago truncatula is sufficient to gain Nod-factor hydrolase activity.

    PubMed

    Zhang, Lan-Yue; Cai, Jie; Li, Ru-Jie; Liu, Wei; Wagner, Christian; Wong, Kam-Bo; Xie, Zhi-Ping; Staehelin, Christian

    2016-07-01

    The symbiotic interaction between nitrogen-fixing rhizobia and legumes depends on lipo-chitooligosaccharidic Nod-factors (NFs). The NF hydrolase MtNFH1 of Medicago truncatula is a symbiotic enzyme that hydrolytically inactivates NFs with a C16 : 2 acyl chain produced by the microsymbiont Sinorhizobium meliloti 1021. MtNFH1 is related to class V chitinases (glycoside hydrolase family 18) but lacks chitinase activity. Here, we investigated the substrate specificity of MtNFH1-related proteins. MtCHIT5a and MtCHIT5b of M. truncatula as well as LjCHIT5 of Lotus japonicus showed chitinase activity, suggesting a role in plant defence. The enzymes failed to hydrolyse NFs from S. meliloti. NFs from Rhizobium leguminosarum with a C18 : 4 acyl moiety were neither hydrolysed by these chitinases nor by MtNFH1. Construction of chimeric proteins and further amino acid replacements in MtCHIT5b were performed to identify chitinase variants that gained the ability to hydrolyse NFs. A single serine-to-proline substitution was sufficient to convert MtCHIT5b into an NF-cleaving enzyme. MtNFH1 with the corresponding proline-to-serine substitution failed to hydrolyse NFs. These results are in agreement with a substrate-enzyme model that predicts NF cleavage when the C16 : 2 moiety is placed into a distinct fatty acid-binding cleft. Our findings support the view that MtNFH1 evolved from the ancestral MtCHIT5b by gene duplication and subsequent symbiosis-related neofunctionalization. PMID:27383628

  8. A single amino acid substitution in a chitinase of the legume Medicago truncatula is sufficient to gain Nod-factor hydrolase activity

    PubMed Central

    Zhang, Lan-Yue; Cai, Jie; Li, Ru-Jie; Liu, Wei; Wagner, Christian; Wong, Kam-Bo; Xie, Zhi-Ping; Staehelin, Christian

    2016-01-01

    The symbiotic interaction between nitrogen-fixing rhizobia and legumes depends on lipo-chitooligosaccharidic Nod-factors (NFs). The NF hydrolase MtNFH1 of Medicago truncatula is a symbiotic enzyme that hydrolytically inactivates NFs with a C16 : 2 acyl chain produced by the microsymbiont Sinorhizobium meliloti 1021. MtNFH1 is related to class V chitinases (glycoside hydrolase family 18) but lacks chitinase activity. Here, we investigated the substrate specificity of MtNFH1-related proteins. MtCHIT5a and MtCHIT5b of M. truncatula as well as LjCHIT5 of Lotus japonicus showed chitinase activity, suggesting a role in plant defence. The enzymes failed to hydrolyse NFs from S. meliloti. NFs from Rhizobium leguminosarum with a C18 : 4 acyl moiety were neither hydrolysed by these chitinases nor by MtNFH1. Construction of chimeric proteins and further amino acid replacements in MtCHIT5b were performed to identify chitinase variants that gained the ability to hydrolyse NFs. A single serine-to-proline substitution was sufficient to convert MtCHIT5b into an NF-cleaving enzyme. MtNFH1 with the corresponding proline-to-serine substitution failed to hydrolyse NFs. These results are in agreement with a substrate-enzyme model that predicts NF cleavage when the C16 : 2 moiety is placed into a distinct fatty acid-binding cleft. Our findings support the view that MtNFH1 evolved from the ancestral MtCHIT5b by gene duplication and subsequent symbiosis-related neofunctionalization. PMID:27383628

  9. Ciliary neurotrophic factor activates leptin-like pathways and reduces body fat, without cachexia or rebound weight gain, even in leptin-resistant obesity

    PubMed Central

    Lambert, P. D.; Anderson, K. D.; Sleeman, M. W.; Wong, V.; Tan, J.; Hijarunguru, A.; Corcoran, T. L.; Murray, J. D.; Thabet, K. E.; Yancopoulos, G. D.; Wiegand, S. J.

    2001-01-01

    Ciliary Neurotrophic Factor (CNTF) was first characterized as a trophic factor for motor neurons in the ciliary ganglion and spinal cord, leading to its evaluation in humans suffering from motor neuron disease. In these trials, CNTF caused unexpected and substantial weight loss, raising concerns that it might produce cachectic-like effects. Countering this possibility was the suggestion that CNTF was working via a leptin-like mechanism to cause weight loss, based on the findings that CNTF acts via receptors that are not only related to leptin receptors, but also similarly distributed within hypothalamic nuclei involved in feeding. However, although CNTF mimics the ability of leptin to cause fat loss in mice that are obese because of genetic deficiency of leptin (ob/ob mice), CNTF is also effective in diet-induced obesity models that are more representative of human obesity, and which are resistant to leptin. This discordance again raised the possibility that CNTF might be acting via nonleptin pathways, perhaps more analogous to those activated by cachectic cytokines. Arguing strongly against this possibility, we now show that CNTF can activate hypothalamic leptin-like pathways in diet-induced obesity models unresponsive to leptin, that CNTF improves prediabetic parameters in these models, and that CNTF acts very differently than the prototypical cachectic cytokine, IL-1. Further analyses of hypothalamic signaling reveals that CNTF can suppress food intake without triggering hunger signals or associated stress responses that are otherwise associated with food deprivation; thus, unlike forced dieting, cessation of CNTF treatment does not result in binge overeating and immediate rebound weight gain. PMID:11259650

  10. Digital automatic gain control

    NASA Technical Reports Server (NTRS)

    Uzdy, Z.

    1980-01-01

    Performance analysis, used to evaluated fitness of several circuits to digital automatic gain control (AGC), indicates that digital integrator employing coherent amplitude detector (CAD) is best device suited for application. Circuit reduces gain error to half that of conventional analog AGC while making it possible to automatically modify response of receiver to match incoming signal conditions.

  11. Weight gain - unintentional

    MedlinePlus

    ... trying to do so can have many causes. Metabolism slows down as you age . This can cause weight gain if you eat too much, eat the wrong foods, or do not get enough exercise. Drugs that can cause weight gain include: Birth control ...

  12. Health gain versus equity.

    PubMed

    Scott-Samuel, A

    1992-05-01

    A new organisation, the Association for Public Health, has just been formed 'to help deliver real health gain for the population'. Alex Scott-Samuel suggests that the concept of 'health gain' is counter to health equality and needs wider debate. PMID:1624317

  13. Invention and Gain Analysis.

    ERIC Educational Resources Information Center

    Weber, Robert J.; Dixon, Stacey

    1989-01-01

    Gain analysis is applied to the invention of the sewing needle as well as different sewing implements and modes of sewing. The analysis includes a two-subject experiment. To validate the generality of gain heuristics and underlying switching processes, the invention of the assembly line is also analyzed. (TJH)

  14. PRECONCEPTION PREDICTORS OF WEIGHT GAIN DURING PREGNANCY

    PubMed Central

    Weisman, Carol S.; Hillemeier, Marianne M.; Downs, Danielle Symons; Chuang, Cynthia H.; Dyer, Anne-Marie

    2010-01-01

    Objectives We examined preconception (prepregnancy) predictors of pregnancy weight gain and weight gain that exceeds the 2009 Institute of Medicine (IOM) recommendations based on pre-pregnancy body mass index (BMI), in a prospective study. Methods Data are from a population-based cohort study of 1,420 women who were interviewed at baseline and 2 years later. The analytic sample includes 103 women who were not pregnant at baseline and gave birth to full-term singletons during the follow-up period. Preconception maternal weight category as well as health behaviors, psychosocial stress, parity, and age were examined as predictors of pregnancy weight gain and of weight gain in excess of the IOM recommendations using multiple linear and logistic regression analysis. Results Pregnancy weight gain averaged 33.01 pounds, with 51% of women gaining weight in excess of the 2009 IOM recommendations for their preconception weight category. Preconception overweight (BMI = 25–29.9) increased the odds of excessive pregnancy weight gain nearly threefold, whereas preconception physical activity levels meeting activity guidelines reduced the odds of excessive weight gain but was marginally statistically significant. Conclusion Although future research examining the role of physical activity in relation to pregnancy weight gain is needed, preconception overweight and physical activity levels are prime targets for interventions to avoid excessive pregnancy weight gain. PMID:20133152

  15. EFFECT OF LASER LIGHT ON MATTER. LASER PLASMAS: Divergence and intensity of amplified spontaneous emission coupled out of an active medium by a distributed refraction method

    NASA Astrophysics Data System (ADS)

    Ladagin, V. K.; Starikov, F. A.; Urlin, V. D.

    1993-05-01

    The dynamics of the radiation in the near and far zones has been studied analytically and numerically for the case in which nonlinearly amplified spontaneous x radiation is coupled out of a plasma active medium by a distributed refraction method. The divergence Δθ of the amplified noise falls off exponentially with increasing length of the active medium, z. When z is equal to five or six refraction lengths, Δθ is an order of magnitude smaller than the geometric divergence. The maximum radiation flux qm is at the refraction angle and increases exponentially with increasing z. The rate of increase of qm and the rate of decrease of Δθ may be lowered by diffraction. In the case of a linear amplification of the noise, qm also corresponds to the refraction angle and may be much greater than the paraxial flux density. However, the advantage over coupling out the end in the case of a homogeneous active medium is achieved at a substantial cost in power.

  16. Serine Substitution of Proline at Codon 151 of TP53 Confers Gain of Function Activity Leading to Anoikis Resistance and Tumor Progression of Head and Neck Cancer Cells

    PubMed Central

    Xie, Tong-Xin; Zhou, Ge; Zhao, Mei; Sano, Daisuke; Jasser, Samar A; Brennan, Richard G; Myers, Jeffrey N.

    2012-01-01

    Objectives/Hypothesis Mutation of the TP53 gene occurs in over half the cases of head and neck squamous cell carcinoma (HNSCC). However, little is known about how specific TP53 mutations affect tumor progression. The objective of this study is to determine the gain of function of mutant p53 with a proline-to-serine substitution at codon 151. Study Design Laboratory based study. Methods A panel of HNSCC cell lines was determined with anoikis assays and orthotopic mouse experiments were performed. TP53 was sequenced. The shRNA knockdown and over-expression approaches were used for testing mutant p53 functions. The crystal structure of the p53 protein was analyzed using an in silico approach. Results An anoikis resistant cell line, Tu138, was found to have a proline-to-serine substitution at codon 151 of TP53, which results in loss of wild-type p53 transcriptional activity. Moreover, the mutant p53 was shown to promote anoikis resistance and soft agar growth. Using an in silico approach based on the crystal structure of wild type p53 protein, substitution of proline by serine at position 151 would create a cavity in a hydrophobic pocket, the loss of van der Waals contacts and the thermodynamically unfavorable placement of a polar group, the hydroxyl oxygen atom of the serine, within a hydrophobic region, all of which likely cause a locally altered structure. Conclusions Our data suggest that mutation at position 151 leads to a structural alteration, which results in significant functional changes in the p53 protein that impact tumor progression. PMID:23625637

  17. Dietary restraint and gestational weight gain

    PubMed Central

    Mumford, Sunni L.; Siega-Riz, Anna Maria; Herring, Amy; Evenson, Kelly R.

    2008-01-01

    Objective To determine whether a history of preconceptional dieting and restrained eating was related to higher weight gains in pregnancy. Design Dieting practices were assessed among a prospective cohort of pregnant women using the Revised Restraint Scale. Women were classified on three separate subscales as restrained eaters, dieters, and weight cyclers. Subjects Participants included 1,223 women in the Pregnancy, Infection and Nutrition Study. Main outcome measures Total gestational weight gain and adequacy of weight gain (ratio of observed/expected weight gain based on Institute of Medicine (IOM) recommendations). Statistical analyses performed Multiple linear regression was used to model the two weight gain outcomes, while controlling for potential confounders including physical activity and weight gain attitudes. Results There was a positive association between each subscale and total weight gain, as well as adequacy of weight gain. Women classified as cyclers gained an average of 2 kg more than non-cyclers, and showed higher observed/expected ratios by 0.2 units. Among restrained eaters and dieters, there was a differential effect by BMI. With the exception of underweight women, all other weight status women with a history of dieting or restrained eating gained more weight during pregnancy and had higher adequacy of weight gain ratios. In contrast, underweight women with a history of restrained eating behaviors gained less weight compared to underweight women without those behaviors. Conclusions Restrained eating behaviors were associated with weight gains above the IOM recommendations for normal, overweight, and obese women, and weight gains below the recommendations for underweight women. Excessive gestational weight gain is of concern given its association with postpartum weight retention. The dietary restraint tool is useful for identifying women who would benefit from nutritional counseling prior to or during pregnancy in regards to achieving targeted

  18. Gain-assisted control of the Goos-Haenchen shift

    SciTech Connect

    Ziauddin,; Qamar, Sajid

    2011-11-15

    A gain-assisted model is considered to study the Goos-Haenchen (GH) shift behavior in the reflected and transmitted light. In this model, a probe light is incident on a cavity containing three-level dilute gaseous atomic medium. The atom-field interaction follows two-photon Raman transitions, and the dielectric susceptibility of the medium exhibits dispersion and gain properties [L. J. Wang, A. Kuzmich, and A. Dogariu, Nature (London) 406, 227 (2000)]. Under appropriate conditions, two gain peaks are observed with anomalous dispersion between the peaks, whereas normal dispersion can be observed at and around the gain maxima. The manipulation of the detuning associated with the probe light field which interacts with the intracavity medium during its propagation through the cavity can lead to a control over negative and positive GH shift in the reflected and transmitted light beam via the anomalous and normal dispersion of the medium.

  19. Formation of the active medium in high-power repetitively pulsed gas lasers pumped by an electron-beam-controlled discharge

    NASA Astrophysics Data System (ADS)

    Bulaev, V. D.; Lysenko, S. L.

    2015-07-01

    A high-power repetitively pulsed e-beam-controlled discharge CO2 laser is simulated numerically; the simulation results are compared with experimental data. Optimal sizes and design of electrodes and configuration of the external magnetic field are found, which allow one to introduce no less than 90% electric pump energy into a specified volume of the active medium, including the active volume of a laser with an aperture of 110 × 110 cm. The results obtained can also be used to design other types of highpower gas lasers.

  20. Preventing Weight Gain

    MedlinePlus

    ... If this is the case, preventing further weight gain is a worthy goal. As people age, their body composition gradually shifts — the proportion of muscle decreases and the proportion of fat increases. This ...

  1. Detection of activity in the conditioned medium of ethanol-treated HepG2 cells which stimulates collagen synthesis in IMR-90 cells.

    PubMed

    Inui, N; Kato, J; Kohgo, Y; Katsuki, S; Niitsu, Y

    1996-02-01

    Hepatic fibrosis often occurs in alcoholic liver diseases without accompanying tissue necrosis or inflammation. However, the precise mechanism of this fibrosis has not been fully clarified. In the present study, using the hepatoblastoma cell line HepG2 as a model for hepatocytes, we identified a factor that stimulates collagen synthesis of fibroblasts in a conditioned medium of HepG2 cells after treatment with ethanol. Type 1 procollagen peptide (PIC) in a culture of human fibroblast IMR-90 markedly increased after incubation with the conditioned medium of ethanol-treated HepG2 cells. The stimulating activity on the production of PIC by IMR-90 remained after the dialysis and evaporation of the conditioned medium of HepG2 cells, indicating this factor was not as volatile from low molecular substances such as acetaldehyde, acetate, or lactate. The activity of this factor diminished with heat or trypsin treatment. A gel chromatographic analysis disclosed that the molecular weight of this factor was approximately 8000 Da. These results suggest that a polypeptide factor secreted from HepG2 cells by treatment with ethanol stimulates collagen synthesis of fibroblasts. PMID:8659693

  2. Active proliferation of Rous sarcoma virus-infected, but not normal, chicken heart mesenchymal cells in culture medium of physiological composition.

    PubMed Central

    Balk, S D

    1980-01-01

    Normal as well as Rous sarcoma virus-infected chicken pectoral and chicken embryo fibroblasts proliferate actively in a plasma containing medium of physiological ion concentrations (Ca2+, 1.2 mM; Mg2+, 0.7 mM). Reduction of medium calcium and magnesium concentrations is necessary to achieve selective quiescence of normal fibroblasts in these cell systems. By contrast, normal chicken heart mesenchymal cells proliferate only sluggishly (one doubling or less during a 6-day period) in a plasma containing medium of physiologic ion concentrations, whereas Rous sarcoma virus-infected heart mesenchymal cells proliferate actively (more than four doublings during an initial 2-day phase of exponential growth). The chicken heart mesenchymal cell system therefore has great potential for studies of the mechanism that initiates cell replication and of the failure in cellular regulatory processes that is responsible for the autonomous initiation of replication of neoplastic cells. From comparison of the chicken heart mesenchymal cell system to dialyzed plasma-based systems in which 3T3 cells tend to proliferative quiescence, it is argued that this proliferative quiescence of 3T3 cells is a result of cell starvation and is not physiologically meaningful. Images PMID:6256750

  3. Scintillator high-gain avalanche rushing photoconductor active-matrix flat panel imager: Zero-spatial frequency x-ray imaging properties of the solid-state SHARP sensor structure

    PubMed Central

    Wronski, M.; Zhao, W.; Tanioka, K.; DeCrescenzo, G.; Rowlands, J. A.

    2012-01-01

    Purpose: The authors are investigating the feasibility of a new type of solid-state x-ray imaging sensor with programmable avalanche gain: scintillator high-gain avalanche rushing photoconductor active matrix flat panel imager (SHARP-AMFPI). The purpose of the present work is to investigate the inherent x-ray detection properties of SHARP and demonstrate its wide dynamic range through programmable gain. Methods: A distributed resistive layer (DRL) was developed to maintain stable avalanche gain operation in a solid-state HARP. The signal and noise properties of the HARP-DRL for optical photon detection were investigated as a function of avalanche gain both theoretically and experimentally, and the results were compared with HARP tube (with electron beam readout) used in previous investigations of zero spatial frequency performance of SHARP. For this new investigation, a solid-state SHARP x-ray image sensor was formed by direct optical coupling of the HARP-DRL with a structured cesium iodide (CsI) scintillator. The x-ray sensitivity of this sensor was measured as a function of avalanche gain and the results were compared with the sensitivity of HARP-DRL measured optically. The dynamic range of HARP-DRL with variable avalanche gain was investigated for the entire exposure range encountered in radiography/fluoroscopy (R/F) applications. Results: The signal from HARP-DRL as a function of electric field showed stable avalanche gain, and the noise associated with the avalanche process agrees well with theory and previous measurements from a HARP tube. This result indicates that when coupled with CsI for x-ray detection, the additional noise associated with avalanche gain in HARP-DRL is negligible. The x-ray sensitivity measurements using the SHARP sensor produced identical avalanche gain dependence on electric field as the optical measurements with HARP-DRL. Adjusting the avalanche multiplication gain in HARP-DRL enabled a very wide dynamic range which encompassed all

  4. Scintillator high-gain avalanche rushing photoconductor active-matrix flat panel imager: Zero-spatial frequency x-ray imaging properties of the solid-state SHARP sensor structure

    SciTech Connect

    Wronski, M.; Zhao, W.; Tanioka, K.; DeCrescenzo, G.; Rowlands, J. A.

    2012-11-15

    Purpose: The authors are investigating the feasibility of a new type of solid-state x-ray imaging sensor with programmable avalanche gain: scintillator high-gain avalanche rushing photoconductor active matrix flat panel imager (SHARP-AMFPI). The purpose of the present work is to investigate the inherent x-ray detection properties of SHARP and demonstrate its wide dynamic range through programmable gain. Methods: A distributed resistive layer (DRL) was developed to maintain stable avalanche gain operation in a solid-state HARP. The signal and noise properties of the HARP-DRL for optical photon detection were investigated as a function of avalanche gain both theoretically and experimentally, and the results were compared with HARP tube (with electron beam readout) used in previous investigations of zero spatial frequency performance of SHARP. For this new investigation, a solid-state SHARP x-ray image sensor was formed by direct optical coupling of the HARP-DRL with a structured cesium iodide (CsI) scintillator. The x-ray sensitivity of this sensor was measured as a function of avalanche gain and the results were compared with the sensitivity of HARP-DRL measured optically. The dynamic range of HARP-DRL with variable avalanche gain was investigated for the entire exposure range encountered in radiography/fluoroscopy (R/F) applications. Results: The signal from HARP-DRL as a function of electric field showed stable avalanche gain, and the noise associated with the avalanche process agrees well with theory and previous measurements from a HARP tube. This result indicates that when coupled with CsI for x-ray detection, the additional noise associated with avalanche gain in HARP-DRL is negligible. The x-ray sensitivity measurements using the SHARP sensor produced identical avalanche gain dependence on electric field as the optical measurements with HARP-DRL. Adjusting the avalanche multiplication gain in HARP-DRL enabled a very wide dynamic range which encompassed all

  5. Microbial activity in argillite waste storage cells for the deep geological disposal of French bituminous medium activity long lived nuclear waste: Impact on redox reaction kinetics and potential

    NASA Astrophysics Data System (ADS)

    Albrecht, A.; Leone, L.; Charlet, L.

    2009-04-01

    Micro-organisms are ubiquitous and display remarkable capabilities to adapt and survive in the most extreme environmental conditions. It has been recognized that microorganisms can survive in nuclear waste disposal facilities if the required major (P, N, K) and trace elements, a carbon and energy source as well as water are present. The space constraint is of particular interest as it has been shown that bacteria do not prosper in compacted clay. An evaluation of the different types of French medium and high level waste, in a clay-rich host rock storage environment at a depth between 500 and 600 m, has shown that the bituminous waste is the most likely candidate to accommodate significant microbial activity. The waste consists of a mixture of bitumen (source of bio-available organic matter and H2 as a consequence of its degradation and radiolysis) and nitrates and sulphates kept in a stainless steel container. The assumption, that microbes only have an impact on reaction kinetics needs to be reassessed in the case where nitrates and sulphates are present since both are known not to react at low temperatures without bacterial catalysis. The additional impact of both oxy-anions and their reduced species on redox conditions, radionuclide speciation and mobility gives this evaluation their particular relevance. Storage architecture proposes four primary waste containers positioned into armoured cement over packs and placed with others into the waste storage cell itself composed of a cement mantle enforcing the argillite host rock, the latter being characterized by an excavation damaged zone constricted both in space and in time and a pristine part of 60 m thickness. Bacterial activity within the waste and within the pristine argillite is disregarded because of the low water activity (< 0.7) and the lack of space, respectively. The most probable zones of microbial activity, those likely to develop sustainable biofilms are within the interface zones. A major restriction

  6. Gain-enhanced hyperbolic metamaterials at telecommunication frequencies (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Smalley, Joseph S. T.; Vallini, Felipe; Kante, Boubacar; Shahin, Shiva; Riley, Conor; Fainman, Yeshaiahu

    2015-09-01

    Using effective medium theory (EMT), Bloch's theorem (BT), and the transfer matrix method (TMM), we analyze the possibility of gain-enhanced transmission in metamaterials with hyperbolic dispersion at telecommunication frequencies. We compare different combinations of dissipative metals and active dielectrics, including noble metals, transparent conducting oxides (TCO), III-V compounds, and solid-state dopants. We find that both indium gallium arsenide phosphide (InGaAsP) and erbium-doped silica (Er:SiO2), when combined with silver, show promise as a platform for demonstration of pump-dependent transmission. On the other hand, when these active dielectrics are combined with aluminum-doped zinc oxide (AZO), a low-loss TCO, gain-enhanced transmission is negligible. Results based on EMT are compared to the more accurate BT and TMM. When losses are ignored, quantitative agreement between these analytical techniques is observed near the center of the first Brillouin zone of a one-dimensional periodic structure. Including realistic levels of loss and gain, however, EMT predictions become overly optimistic compared to BT and TMM. We also discuss the limitations to assumptions inherent to EMT, BT, and TMM, and suggest avenues for future analysis.

  7. DNA polymorphisms and transcript abundance of PRKAG2 and phosphorylated AMP-activated protein kinase in the rumen are associated with gain and feed intake in beef steers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beef steers with variation in feed efficiency phenotypes were evaluated previously on a high density SNP panel. Ten markers from rs110125325-rs41652818 on bovine chromosome 4 were associated with average daily gain (ADG). To identify the gene(s) in this 1.2Mb region responsible for variation in AD...

  8. Formation and catalytic activity of high molecular weight soluble polymers produced by heating amino acids in a modified sea medium

    NASA Astrophysics Data System (ADS)

    Okihana, Hiroyuki

    1982-06-01

    Eighteen protein amino acids with milk casein composition were heated in a modified sea medium. Marigranules were formed in the precipitates and soluble polymers were formed in the supernatant. Time course of the reaction (ultraviolet spectra, the concentration of metal ions, and the concentration of amino acids in the supernatant) were measured. The time course of the formation of the soluble polymers was also studied by Bio-Gel P-2 column. High molecular weight soluble polymers (HMWSP) were separated from low molecular weight ones by dialysis. It was shown that these polymers catalyzed the dehydrogenation of NADH. These polymers also catalyzed the coupled reaction between dehydrogenation of NADH and reduction of resazurin. This coupled reaction was accelerated by the light.

  9. Receiver Gain Modulation Circuit

    NASA Technical Reports Server (NTRS)

    Jones, Hollis; Racette, Paul; Walker, David; Gu, Dazhen

    2011-01-01

    A receiver gain modulation circuit (RGMC) was developed that modulates the power gain of the output of a radiometer receiver with a test signal. As the radiometer receiver switches between calibration noise references, the test signal is mixed with the calibrated noise and thus produces an ensemble set of measurements from which ensemble statistical analysis can be used to extract statistical information about the test signal. The RGMC is an enabling technology of the ensemble detector. As a key component for achieving ensemble detection and analysis, the RGMC has broad aeronautical and space applications. The RGMC can be used to test and develop new calibration algorithms, for example, to detect gain anomalies, and/or correct for slow drifts that affect climate-quality measurements over an accelerated time scale. A generalized approach to analyzing radiometer system designs yields a mathematical treatment of noise reference measurements in calibration algorithms. By treating the measurements from the different noise references as ensemble samples of the receiver state, i.e. receiver gain, a quantitative description of the non-stationary properties of the underlying receiver fluctuations can be derived. Excellent agreement has been obtained between model calculations and radiometric measurements. The mathematical formulation is equivalent to modulating the gain of a stable receiver with an externally generated signal and is the basis for ensemble detection and analysis (EDA). The concept of generating ensemble data sets using an ensemble detector is similar to the ensemble data sets generated as part of ensemble empirical mode decomposition (EEMD) with exception of a key distinguishing factor. EEMD adds noise to the signal under study whereas EDA mixes the signal with calibrated noise. It is mixing with calibrated noise that permits the measurement of temporal-functional variability of uncertainty in the underlying process. The RGMC permits the evaluation of EDA by

  10. Administration of activated glial condition medium in the nucleus accumbens extended extinction and intensified reinstatement of methamphetamine-induced conditioned place preference.

    PubMed

    Arezoomandan, Reza; Moradi, Marzieh; Attarzadeh-Yazdi, Ghassem; Tomaz, Carlos; Haghparast, Abbas

    2016-07-01

    Methamphetamine (METH) is a psychostimulant drug with significant abuse potential and neurotoxic effects. A high percentage of users relapse to use after detoxification and no effective medication has been developed for treatment of METH addiction. Developing evidences indicated the role of glial cells in drugs abused related phenomena. However, little is known about the role of these cells in the maintenance and reinstatement of METH-seeking behaviors. Therefore, the current study was conducted to clarify the role of glial cells in the maintenance and reinstatement of METH-induced conditioned place preference (CPP) in rats. Astrocyte condition medium (ACM) and neuroglia conditioned medium (NCM) are liquid mediums prepared from primary astrocyte and neuroglia cells. These mediums seem to contain many factors that release by glia cells. CPP was induced by systemic administration of METH (1mg/kg for 5days, s.c.). Following the establishment of CPP, the rats were given daily bilateral injections (0.5μl/side) of either vehicle, ACM or NCM into the nucleus accumbens (NAc) and then were tested for the maintenance and reinstatement. Intra-NAc administration of ACM treated with METH, could extend the extinction period and also, intensified the magnitude of METH reinstatement. Furthermore, intra-accumbal administration of NCM treated with METH notably delayed the extinction period by four days and significantly increased the magnitude of CPP score in the reinstatement phase compared to the post-test phase. Collectively, these findings suggested that activation of glial cells may be involved in the maintenance and reinstatement of METH-seeking behaviors. It provides new evidence that glia cells might be considered as a potential target for the treatment of METH addiction. PMID:27346277

  11. Eruptive activity of enigmatic medium-sized volcanoes in the Michoacán-Guanajuato Volcanic Field (MGVF), Central Mexico: The case of El Metate

    NASA Astrophysics Data System (ADS)

    Chevrel, M.; Siebe, C.; Guilbaud, M. N.

    2014-12-01

    The MGVF has a total area of ca. 40,000 km2 and is well known for being the host of the only two monogenetic volcanoes in Mexico that were born in historical times: Jorullo (1759-1774) and Paricutin (1943-1952). Another particularity of the MGVF is its high number of eruptive vents with over 1000 small monogenetic cones and associated lava flows (average vol. of 0.021 km3) and ca. 400 medium-sized volcanoes (average vol. from 0.5 to 50 km3). Most of these medium-sized volcanoes may be characterized as shields that were produced dominantly by effusive activity as opposed to the small cones formed also by explosive phases of activity. The products of the small cones range from olivine basalts to andesites whereas the medium-sized volcanoes are restricted to a smaller compositional range in the andesitic domain. Although the medium-sized volcanoes are more sparsely distributed in time and space and less abundant than the small cones, the risks associated with renewal of this type of activity should not be neglected. This study focuses on El Metate which is probably the youngest shield of the MGVF (< 3,700 y. BP). Unlike a typical shield volcano composed of a succession of thin fluid basaltic flows, El Metate consists of well-preserved >60 m thick andesite flows distributed radially around a summit dome. Detailed mapping and sampling allowed us to reconstruct its eruptive activity and the time sequence of lava flow emplacement. We have identified 13 individual lava flows with lengths ranging between 3 and 15 km covering 103 km2 and average thicknesses between 60 and 150 m. Individual volumes range between 0.5 and 3.5 km3 for a total of 11 to 15 km3. Estimates of flow emplacement parameters indicate maximum average effusion rates ranging between 15 and 100 m3.s-1 and a cumulative duration from 15 to 30 years. Such a short emplacement time is comparable to the historical monogenetic eruption of nearby Paricutin volcano (9 years) but the erupted volume of lava is

  12. PHYSICAL EFFECTS OCCURRING DURING GENERATION AND AMPLIFICATION OF LASER RADIATION: Discharge energy balance in the nitrogen-containing active medium of an electron-beam-controlled CO laser

    NASA Astrophysics Data System (ADS)

    Dolinina, V. I.; Koterov, V. N.; Pyatakhin, Mikhail V.; Urin, B. M.

    1989-02-01

    Numerical methods were used to investigate theoretically the dynamics of the energy balance of a discharge in a CO-N2 mixture, taking into account the mutual influence of the distributions of the electron energy and of the populations of the molecules over the vibrational levels. It was shown that this influence plays a decisive part in substantially redistributing the pump energy between the vibrational levels of the CO and N2 molecules in favor of the N2 molecules. A stabilizing action of the nitrogen on the thermal regime of the CO laser-active medium was discovered and the range of optimal CO:N2 ratios was determined.

  13. Random lasing in a nanocomposite medium

    SciTech Connect

    Smetanin, Sergei N; Basiev, Tasoltan T

    2013-01-31

    The characteristics of a random laser based on a nanocomposite medium consisting of a transparent dielectric and scattering doped nanocrystals are calculated. It is proposed to use ytterbium laser media with a high concentration of active ions as nanocrystals and to use gases, liquids, or solid dielectrics with a refractive index lower than that of nanocrystals as dielectric matrices for nanocrystals. Based on the concept of nonresonant distributed feedback due to the Rayleigh scattering, an expression is obtained for the minimum length of a nanocomposite laser medium at which the random lasing threshold is overcome. Expressions are found for the critical (maximum) and the optimal size of nanocrystals, as well as for the optimal relative refractive index of nanocomposites that corresponds not only to the maximum gain but also to the minimum of the medium threshold length at the optimal size of nanocrystals. It is shown that the optimal relative refractive index of a nanocomposite increases with increasing pump level, but is independent of the other nanocomposite parameters. (nanocomposites)

  14. Early metabolic adaptation in C57BL/6 mice resistant to high fat diet induced weight gain involves an activation of mitochondrial oxidative pathways.

    PubMed

    Boulangé, Claire L; Claus, Sandrine P; Chou, Chieh J; Collino, Sebastiano; Montoliu, Ivan; Kochhar, Sunil; Holmes, Elaine; Rezzi, Serge; Nicholson, Jeremy K; Dumas, Marc E; Martin, François-Pierre J

    2013-04-01

    We investigated the short-term (7 days) and long-term (60 days) metabolic effect of high fat diet induced obesity (DIO) and weight gain in isogenic C57BL/6 mice and examined the specific metabolic differentiation between mice that were either strong-responders (SR), or non-responders (NR) to weight gain. Mice (n = 80) were fed a standard chow diet for 7 days prior to randomization into a high-fat (HF) (n = 56) or a low-fat (LF) (n = 24) diet group. The (1)H NMR urinary metabolic profiles of LF and HF mice were recorded 7 and 60 days after the diet switch. On the basis of the body weight gain (BWG) distribution of HF group, we identified NR mice (n = 10) and SR mice (n = 14) to DIO. Compared with LF, HF feeding increased urinary excretion of glycine conjugates of β-oxidation intermediate (hexanoylglycine), branched chain amino acid (BCAA) catabolism intermediates (isovalerylglycine, α-keto-β-methylvalerate and α-ketoisovalerate) and end-products of nicotinamide adenine dinucleotide (NAD) metabolism (N1-methyl-2-pyridone-5-carboxamide, N1-methyl-4-pyridone-3-carboxamide) suggesting up-regulation of mitochondrial oxidative pathways. In the HF group, NR mice excreted relatively more hexanoylglycine, isovalerylglycine, and fewer tricarboxylic acid (TCA) cycle intermediate (succinate) in comparison to SR mice. Thus, subtle regulation of ketogenic pathways in DIO may alleviate the saturation of the TCA cycle and mitochondrial oxidative metabolism. PMID:23473242

  15. ASE suppression in high-gain solid-state amplifiers by a leak method

    NASA Astrophysics Data System (ADS)

    Zhang, Yongliang; Ye, Haixian; Li, Mingzhong; Zheng, Jiangang; Wei, Xiaofeng; Gao, Song; Deng, Qinghua; Jiang, Xinying; Yan, Xiongwei; Wang, Zhenguo

    2013-07-01

    A leak method was developed to suppress amplified spontaneous emission (ASE) in large-aperture high-gain solid-state amplifiers. The gain medium edges are processed into an arris. The ASE ray will undergo reflection several times at the arris surface when it propagates to the gain medium edges, and most of its power will leak out. This leak method was tested in an experiment, in which a piece of commonly used gain medium was processed for contrast. The maximal increase of the gain value was 5.26% with the maximal pump power.

  16. Activator-inhibitor coupling between Rho signaling and actin assembly make the cell cortex an excitable medium

    PubMed Central

    Bement, William M.; Leda, Marcin; Moe, Alison M.; Kita, Angela M.; Larson, Matthew E.; Golding, Adriana E.; Pfeuti, Courtney; Su, Kuan-Chung; Miller, Ann L.; Goryachev, Andrew B.; von Dassow, George

    2016-01-01

    Animal cell cytokinesis results from patterned activation of the small GTPase Rho, which directs assembly of actomyosin in the equatorial cortex. Cytokinesis is restricted to a portion of the cell cycle following anaphase onset in which the cortex is responsive to signals from the spindle. We show that shortly after anaphase onset oocytes and embryonic cells of frogs and echinoderms exhibit cortical waves of Rho activity and F-actin polymerization. The waves are modulated by cyclin-dependent kinase 1 (Cdk1) activity and require the Rho GEF (guanine nucleotide exchange factor), Ect2. Surprisingly, during wave propagation, while Rho activity elicits F-actin assembly, F-actin subsequently inactivates Rho. Experimental and modeling results show that waves represent excitable dynamics of a reaction diffusion system with Rho as the activator and F-actin the inhibitor. We propose that cortical excitability explains fundamental features of cytokinesis including its cell cycle regulation. PMID:26479320

  17. Activator-inhibitor coupling between Rho signalling and actin assembly makes the cell cortex an excitable medium.

    PubMed

    Bement, William M; Leda, Marcin; Moe, Alison M; Kita, Angela M; Larson, Matthew E; Golding, Adriana E; Pfeuti, Courtney; Su, Kuan-Chung; Miller, Ann L; Goryachev, Andrew B; von Dassow, George

    2015-11-01

    Animal cell cytokinesis results from patterned activation of the small GTPase Rho, which directs assembly of actomyosin in the equatorial cortex. Cytokinesis is restricted to a portion of the cell cycle following anaphase onset in which the cortex is responsive to signals from the spindle. We show that shortly after anaphase onset oocytes and embryonic cells of frogs and echinoderms exhibit cortical waves of Rho activity and F-actin polymerization. The waves are modulated by cyclin-dependent kinase 1 (Cdk1) activity and require the Rho GEF (guanine nucleotide exchange factor), Ect2. Surprisingly, during wave propagation, although Rho activity elicits F-actin assembly, F-actin subsequently inactivates Rho. Experimental and modelling results show that waves represent excitable dynamics of a reaction-diffusion system with Rho as the activator and F-actin the inhibitor. We propose that cortical excitability explains fundamental features of cytokinesis including its cell cycle regulation. PMID:26479320

  18. Effect of the dipole-dipole interaction of particles in an active medium on the character of superradiation

    NASA Astrophysics Data System (ADS)

    Berezovsky, V. V.; Men'shikov, L. I.; Oberg, S.; Latham, C. D.

    2008-07-01

    The motion of a system of interacting nonlinear charged oscillators is investigated numerically. Because of nonlinearity, the total collective electric field gives rise to a phasing effect—correlations in the phases of the oscillators. The consequence is superradiation—the enhanced spontaneous short-term emission of the energy stored in the oscillators. It is shown that the oscillations of the oscillators become stochastic because of the dipole-dipole interaction between them and their nearest neighbors. As a result, as the density of the oscillators increases, distant collective correlations are suppressed, superradiation ceases to be generated, and radiation is shielded in the medium. The phenomena considered in the present paper can play an important role in cyclotron emission from a plasma and thus should be taken into account in emission calculations. The process whereby the energy of the transverse electron motion in electron cooling devices decreases is analyzed as an example. This process occurs as a result of the development of cyclotron maser instability and has the nature of superradiation. The onset of correlations between individual electrons moving in their Larmor circles is the initial, linear stage of instability developing in the plasma. Superradiation is the final, nonlinear instability stage.

  19. Improvement of Medium Chain Fatty Acid Content and Antimicrobial Activity of Coconut Oil via Solid-State Fermentation Using a Malaysian Geotrichum candidum

    PubMed Central

    Khoramnia, Anahita; Ebrahimpour, Afshin; Ghanbari, Raheleh; Ajdari, Zahra; Lai, Oi-Ming

    2013-01-01

    Coconut oil is a rich source of beneficial medium chain fatty acids (MCFAs) particularly lauric acid. In this study, the oil was modified into a value-added product using direct modification of substrate through fermentation (DIMOSFER) method. A coconut-based and coconut-oil-added solid-state cultivation using a Malaysian lipolytic Geotrichum candidum was used to convert the coconut oil into MCFAs-rich oil. Chemical characteristics of the modified coconut oils (MCOs) considering total medium chain glyceride esters were compared to those of the normal coconut oil using ELSD-RP-HPLC. Optimum amount of coconut oil hydrolysis was achieved at 29% moisture content and 10.14% oil content after 9 days of incubation, where the quantitative amounts of the modified coconut oil and MCFA were 0.330 mL/g of solid media (76.5% bioconversion) and 0.175 mL/g of solid media (53% of the MCO), respectively. MCOs demonstrated improved antibacterial activity mostly due to the presence of free lauric acid. The highest MCFAs-rich coconut oil revealed as much as 90% and 80% antibacterial activities against Staphylococcus aureus and Escherichia coli, respectively. The results of the study showed that DIMOSFER by a local lipolytic G. candidum can be used to produce MCFAs as natural, effective, and safe antimicrobial agent. The produced MCOs and MCFAs could be further applied in food and pharmaceutical industries. PMID:23971051

  20. Effect of Short-Term Stimulation with Interleukin-1β and Differentiation Medium on Human Mesenchymal Stromal Cell Paracrine Activity in Coculture with Osteoblasts

    PubMed Central

    Voss, Jan O.; Loebel, Claudia; Bara, Jennifer J.; Fussinger, Marc Anton; Alini, Mauro; Stoddart, Martin J.

    2015-01-01

    Introduction. Human mesenchymal stromal cells (hMSCs) exhibit the potential to accelerate bone healing by enhanced osteogenic differentiation. Interleukin-1β is highly expressed during fracture healing and has been demonstrated to exert a significant impact on the differentiation behaviour of hMSCs. Here, we investigate the effect of 2-hour IL-1β stimulation on the differentiation and paracrine activity of hMSCs in coculture with osteosarcoma cells in vitro. Methods. hMSCs from 3 donors were incubated for 2 hours with 10 ng/mL IL-1β and subsequently cocultured with MG63-GFP cells either in control or in differentiation medium in a transwell system for 28 days. Genetic and functional effects were investigated. Results. hMSCs cultured in control medium exhibited a regulatory effect on cocultured MG63-GFP cells, resulting in upregulation of osteogenic gene expression in combination with increased ALP activity. However, while stimulated hMSCs cultured under differentiation conditions exhibit signs of osteogenic differentiation, osteogenic differentiation also caused an impaired regulatory effect on the cocultured MG63-GFP cells. Conclusion. Short stimulation of hMSCs has the potential to modify their long-term behaviour. In addition, undifferentiated hMSCs are able to regulate osteoblast differentiation; however, this regulatory function is lost upon osteogenic differentiation in vitro. This offers a novel approach for clinical cell therapy protocols. PMID:26798640

  1. Novel As-doped, As and N-codoped carbon nanotubes as highly active and durable electrocatalysts for O2 reduction in alkaline medium

    NASA Astrophysics Data System (ADS)

    Liu, Ziwu; Li, Meng; Wang, Fang; Wang, Quan-De

    2016-02-01

    To develop more efficient metal-free cathode electrocatalysts for fuel cells, novel arsenic (As)-doped, As and N-codoped carbon nanotubes are synthesized by chemical vapor deposition in this work. The as-prepared As-containing carbon nanotubes exhibit significantly enhanced activity and long-term durability for the oxygen reduction reaction (ORR) in alkaline medium, indicating that the doping of As or codoping As with other heteroatoms into carbon matrix could improve the ORR activity of carbon materials due to the changes in electronic and physical properties of carbon nanotubes evidenced by density functional theory calculations. Moreover, As-containing carbon nanotubes also display much better methanol tolerance, showing a good potential application for future fuel cells.

  2. Amoco technique gains support

    SciTech Connect

    1995-10-01

    Amoco Corp.`s low-cost horizontal drilling technique and equipment are gaining acceptance in the oilpatch after five years of design and fine-tuning work. The system is purely mechanical, and it`s designed to operate with a workover rig instead of a drilling rig. It`s engineered to drill short-radius horizontal wells with lateral sup to 1,000 feet, so far.

  3. Evaluation of the catalytic activity of Pd-Ag alloys on ethanol oxidation and oxygen reduction reactions in alkaline medium

    NASA Astrophysics Data System (ADS)

    Oliveira, M. C.; Rego, R.; Fernandes, L. S.; Tavares, P. B.

    2011-08-01

    Pd-Ag alloys containing different amounts of Ag (8, 21 and 34 at.%) were prepared in order to evaluate their catalytic activity towards the ethanol oxidation (EOR) and oxygen reduction (ORR) reactions. A sequential electroless deposition of Ag and Pd on a stainless steel disc, followed by annealing at 650 °C under Ar stream, was used as the alloy electrode deposition process. From half-cell measurements in a 1.0 M NaOH electrolyte at ≅20 °C, it was found that alloying Pd with Ag leads to an increases of the ORR and EOR kinetics, relative to Pd. Among the alloys under study, the 21 at.% Ag content alloy presents the highest catalytic activity for the EOR and the lowest Ag content alloy (8 at.% Ag) shows the highest ORR activity. Moreover, it was found that the selectivity of Pd-Ag alloys towards ORR is sustained when ethanol is present in the electrolyte.

  4. A rate equation approach to gain saturation effects in laser mode calculations

    NASA Technical Reports Server (NTRS)

    Roberts, Lila F.

    1990-01-01

    Space exploration and research require large amounts of power. Solar pumped laser systems have been shown to have the potential for meeting the performance requirements necessary for power transmission in space. The successful design of laser systems for these applications will depend, in part, on having a clear understanding of the development of the dynamical processes in the laser cavity and on the effects that changes in physical and design parameters have on laser performance. In particular, it is necessary to know the amplitude and phase distributions of the laser beam at the output aperture when steady state operation is achieved in order to determine the far-field power distribution. The output from the laser will depend on the active medium, the optical environment of the active material and on the gain distribution in the active region as laser action builds up and reaches steady state. An important component in the design process will be a realistic model of the active laser cavity. A computer model of the laser cavity, based on Huygens' principle was developed. The code calculates the amplitude and phase of an optical wave reflected back and forth between the mirrors of a laser cavity. The original code assumes a gain distribution which does not change with the buildup of oscillations in the cavity. A step in the direction of realism is the inclusion of a saturable gain medium in the cavity. The objective is to incorporate saturation effects into the existing computer model.

  5. Enhanced antibacterial activity of copper/copper oxide nanowires prepared by pulsed laser ablation in water medium

    NASA Astrophysics Data System (ADS)

    Swarnkar, R. K.; Pandey, J. K.; Soumya, K. K.; Dwivedi, P.; Sundaram, S.; Prasad, Sanjay; Gopal, R.

    2016-07-01

    Copper/copper oxide nanowires (NWs) are well known for its antibacterial activity against various pathogens. In the present study, we have shown the enhanced antibacterial activity of the NWs against gram-negative bacterial strains ( Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi) and gram-positive bacterial strains ( Bacillus subtilis and Staphylococcus aureus). The increase in the activity is because of the shape and size of the colloidal NWs which were prepared at room temperature in a one-step process by pulsed laser ablation of copper metal target. The purity, shape and size of the colloidal NWs were well characterized by UV-visible absorption spectroscopy and transmission electron microscopy (TEM). The NWs were of diameters in the range of 15-30 nm and lengths ranging from 200 to 600 nm. The dose-dependent antibacterial activity of these NWs was found to be more effective against gram-negative bacteria compared to gram-positive bacteria. As gram-negative bacteria have thinner layer of cell wall made up of peptidoglycan possibly which makes them more susceptible to Cu/Cu2O NWs, Cu/Cu2O NWs can be a potent candidate to be used as bactericidal or as growth inhibitor.

  6. 75 FR 9431 - Small and Medium-Sized Enterprises: U.S. and EU Export Activities, and Barriers and Opportunities...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-02

    ... October 28, 2009 (74 FR 55581); December 1, 2009 (74 FR 62812); and December 11, 2009 (74 FR 65787). A... the Federal Register of February 4, 2010 (75 FR 5804). Washington Hearing: The rescheduled Washington... Government activity was cancelled due to a snow storm. Persons wishing to appear at the March 18...

  7. Improvement of the antifungal activity of lactic acid bacteria by addition to the growth medium of phenylpyruvic acid, a precursor of phenyllactic acid.

    PubMed

    Valerio, Francesca; Di Biase, Mariaelena; Lattanzio, Veronica M T; Lavermicocca, Paola

    2016-04-01

    The aim of the current study was to improve the antifungal activity of eight lactic acid bacterial (LAB) strains by the addition of phenylpyruvic acid (PPA), a precursor of the antifungal compound phenyllactic acid (PLA), to a defined growth medium (DM). The effect of PPA addition on the LABs antifungal activity related to the production of organic acids (PLA, d-lactic, l-lactic, acetic, citric, formic and 4-hydroxy-phenyllactic acids) and of other phenylpyruvic-derived molecules, was investigated. In the presence of PPA the inhibitory activity (expressed as growth inhibition percentage) against fungal bread contaminants Aspergillus niger and Penicillium roqueforti significantly increased and was, even if not completely, associated to PLA increase (from a mean value of 0.44 to 0.93 mM). While the inhibitory activity against Endomyces fibuliger was mainly correlated to the low pH and to lactic, acetic and p-OH-PLA acids. When the PCA analysis based on data of growth inhibition percentage and organic acid concentrations was performed, strains grown in DM+PPA separated from those grown in DM and the most active strains Lactobacillus plantarum 21B, Lactobacillus fermentum 18B and Lactobacillus brevis 18F grouped together. The antifungal activity resulted to be strain-related, based on a different mechanism of action for filamentous fungi and the yeast and was not exclusively associated to the increase of PLA. Therefore, a further investigation on the unique unidentified peak in HPLC-UV chromatograms, was performed by LC-MS/MS analysis. Actually, full scan mass spectra (negative ion mode) recorded at the retention time of the unknown compound, showed a main peak of m/z 291.0 which was consistent with the nominal mass of the molecular ion [M-H](-) of polyporic acid, a PPA derivative whose antifungal activity has been previously reported (Brewer et al., 1977). In conclusion, the addition of PPA to the growth medium contributed to improve the antifungal activity of LAB

  8. Old-age, survivors, and disability insurance and Supplemental Security Income for the aged, blind, and disabled; substantial gainful activity amounts; "services" for trial work period purposes--monthly amounts; student child earned income exclusion. Social Security Administration. Final rules.

    PubMed

    2000-12-29

    We are revising the rules to automatically adjust each year, based on any increases in the national average wage index, the average monthly earnings guideline we use to determine whether work done by persons with impairments other than blindness is substantial gainful activity; provide that we will ordinarily find that an employee whose average monthly earnings are not greater than the "primary substantial gainful activity amount," has not engaged in substantial gainful activity without considering other information beyond the employee's earnings; increase the minimum amount of monthly earnings and the minimum number of self-employed work hours in month that we consider shows that a person receiving title II Social Security benefits based on disability is performing or has performed "services" during a trial work period, and automatically adjust the earnings amount each year thereafter; increase the maximum monthly and yearly Student Earned Income Exclusion amounts we use in determining Supplemental Security Income (SSI) Program eligibility and payment amounts for student children, and automatically adjust the monthly and yearly exclusion amounts each year thereafter. We are revising these rules as part of our efforts to encourage individuals with disabilities to test their ability to work and keep working. We expect that these changes will provide greater incentives for many beneficiaries to attempt to work or, if already working, to continue to work or increase their work effort. PMID:11503739

  9. Leptin Effect on Acetylation and Phosphorylation of Pgc1α in Muscle Cells Associated With Ampk and Akt Activation in High-Glucose Medium.

    PubMed

    García-Carrizo, Francisco; Nozhenko, Yuriy; Palou, Andreu; Rodríguez, Ana M

    2016-03-01

    Leptin is crucial in energy metabolism, including muscle regulation. Peroxisome proliferator activated receptor gamma co-activator 1α (PGC1α) orchestrates energy metabolism and is tightly controlled by post-translational covalent modifications such as phosphorylation and acetylation. We aimed to further the knowledge of PGC1α control by leptin (at physiological levels) in muscle cells by time-sequentially analysing the activation of AMP activated protein kinase (AMPK), P38 mitogen-activated protein kinase (P38 MAPK) and Akt (Protein kinase B)--all known to phosphorylate PGC1α and to be involved in the regulation of its acetylation status--in C2C12 myotubes placed in a high-glucose serum-free medium. We also studied the protein levels of PGC1α, Sirtuin 1, adiponectin, COX IV, mitofusin 2 (Mfn2), and pyruvate dehydrogenase kinase 4 (PDK4). Our main findings suggest an important role of leptin regulating AMPK and Akt phosphorylation, Mfn2 induction and PGC1α acetylation status, with the novelty that the latter in transitorily increased in response to leptin, an effect dependent, at least in part, on AMPK regulation. These post-translational reversible changes in PGC1α in response to leptin, especially the increase in acetylation status, may be related to the physiological role of the hormone in modulating muscle cell response to the physiological/nutritional status. PMID:26218179

  10. Influence of the reaction medium on enzyme activity in bio-organic synthesis: behaviour of lipase from Candida rugosa in the presence of polar additives.

    PubMed

    Triantafyllou, A O; Adlercreutz, P; Mattiasson, B

    1993-04-01

    Lipase from Candida rugosa immobilized on Celite was employed as the biocatalyst in order to examine the effect of the reaction medium upon enzymic activity and selectivity. As the model reaction, transesterification between tributyrin and pentan-2-ol in iso-octane (2,2,4-trimethylpentane) was chosen. A small amount of water (0.05%, v/v) was added to the reaction medium. Enhanced transesterification yields and increased selectivity of the lipase could be obtained by manipulating the microenvironment of the catalyst. Addition of 0.2% NN-dimethylformamide allowed a 93% higher ester yield compared with that obtained when no extra addition was made. Under the same conditions, the ratio of the amount of transesterification product over the amount of hydrolysis product after 48 h, became 52% higher than the ratio determined in the absence of additives. It was concluded that addition of compounds that have low logP3 (P is the partition coefficient in the octanol/water two-phase system) values and high dielectric constant was advantageous in order to favour transesterification over hydrolytic processes. PMID:8484905

  11. An Active Form of Sphingosine Kinase-1 Is Released in the Extracellular Medium as Component of Membrane Vesicles Shed by Two Human Tumor Cell Lines

    PubMed Central

    Rigogliuso, Salvatrice; Donati, Chiara; Cassarà, Donata; Taverna, Simona; Salamone, Monica; Bruni, Paola; Vittorelli, Maria Letizia

    2010-01-01

    Expression of sphingosine kinase-1 (SphK-1) correlates with a poor survival rate of tumor patients. This effect is probably due to the ability of SphK-1 to be released into the extracellular medium where it catalyzes the biosynthesis of sphingosine-1-phosphate (S1P), a signaling molecule endowed with profound proangiogenic effects. SphK-1 is a leaderless protein which is secreted by an unconventional mechanism. In this paper, we will show that in human hepatocarcinoma Sk-Hep1 cells, extracellular signaling is followed by targeting the enzyme to the cell surface and parallels targeting of FGF-2 to the budding vesicles. We will also show that SphK-1 is present in a catalitycally active form in vesicles shed by SK-Hep1 and human breast carcinoma 8701-BC cells. The enzyme substrate sphingosine is present in shed vesicles where it is produced by neutral ceramidase. Shed vesicles are therefore a site for S1P production in the extracellular medium and conceivably also within host cell following vesicle endocytosis. PMID:20508814

  12. [Diversity, relative abundance and activity patterns of medium and large mammals in a tropical deciduous forest in the Isthmus of Tehuantepec, Oaxaca, Mexico].

    PubMed

    Cortés-Marcial, Malinalli; Briones-Salas, Miguel

    2014-12-01

    The use of camera traps and mammal track search are complementary methods to monitoring species of which is not well documented their natural history, as in the case of medium and large mammals. To ensure its conservation and good management, it is necessary to generate information about the structure of the community and their populations. The objective of the present study was to estimate the diversity, relative abundance and activity patterns of medium and large mammals in a tropical deciduous forest located in the Isthmus of Tehuantepec, Oaxaca, Mexico. Samplings were conducted in three month intervals, from September 2011 to May 2013. We used photographic-sampling and track search, two complementary sampling methods. For photographic-sampling, 12 camera traps were placed covering an area of 60 km2, while for the tracks search a monthly tour of four line-transect surveys of three kilometers length each was undertaken. We obtained a total of 344 pictures with 5292 trap-days total sampling effort; in addition, 187 track records in a total of 144 km. With both methods we registered 21 species of mammals, in 13 families and seven orders, and five species resulted in new records to the area. The diversity index of Shannon-Wiener obtained with the method of tracks was H' = 2.41, while the most abundant species were Urocyon cinereoargen- teus (IAR = 0.23) and Pecari tajacu (IAR = 0.20). By the method of trap the most abundant species were P. tajacu (IAR = 2.62) and Nasua narica (IAR = 1.28). In terms of patterns of activity P. tajacu, N. narica and Odocoileus virginianus were primarily diurnal species; Canis latrans and Leopardus pardalis did not show preference for any schedule in particular, and Didelphis virginiana and Dasypus novemcinctus preferred to have nocturnal activity. This information can be of help to the creation of programs of management and conservation of mam- mals of medium and large in the Isthmus of Tehuantepec, Oaxaca, México. PMID:25720178

  13. Helicopter high gain control

    NASA Technical Reports Server (NTRS)

    Cunningham, T. B.; Nunn, E. C.

    1979-01-01

    High gain control is explored through a design study of the CH-47B helicopter. The plans are designed to obtain the maximum bandwidth possible given the hardware constraints. Controls are designed with modal control theory to specific bandwidths and closed loop mode shapes. Comparisons are made to an earlier complementary filter approach. Bandwidth improvement by removal of limitations is explored in order to establish hardware and mechanization options. Improvements in the pitch axis control system and in the rate gyro sensor noise characteristics in all axes are discussed. The use of rotor state feedback is assessed.

  14. Prospects of medium specific activity (177) Lu in targeted therapy of prostate cancer using (177) Lu-labeled PSMA inhibitor.

    PubMed

    Chakraborty, Sudipta; Chakravarty, Rubel; Shetty, Priyalata; Vimalnath, K V; Sen, Ishita B; Dash, Ashutosh

    2016-07-01

    Targeted radionuclide therapy using (177) Lu-labeled peptidomimetic inhibitor of prostate specific membrane antigen (PSMA) viz. PSMA-617 is emerging as one the most effective strategies for management of metastatic prostate cancer, which is one of the leading causes of cancer related death. The aim of the present study is to develop a robust and easily adaptable protocol for formulation of therapeutic dose of (177) Lu-PSMA-617 at hospital radiopharmacy using moderate specific activity (177) Lu available at an affordable cost. Extensive radiochemical studies were performed to optimize the required [PSMA-617] / [Lu] ratio and other parameters to formulate 7.4 GBq dose of (177) Lu-PSMA-617. Based on these, 7.4 GBq therapeutic dose of (177) Lu-PSMA-617 was formulated by incubating 160 µg of PSMA-617 with indigenously produced (177) LuCl3 (555 GBq/µg specific activity of (177) Lu) at 90 °C for 30 min. The radiochemical purity of the formulation was 98.3 ± 0.6% (n = 7) which was retained to the extent of >95% after 7 d in normal saline at room temperature and >96% after 2 d in human serum at 37 °C. Preliminary clinical studies showed specific targeting of the agent in the lesion sites and similar physiological distribution as in diagnostic (68) Ga-PSMA-11 PET scans performed earlier. The developed optimized protocol for formulating therapeutic dose of (177) Lu-PSMA-617 could be useful for large number of nuclear medicine therapy clinics across the world having access to moderate specific activity (177) Lu at an affordable cost. PMID:27264278

  15. Enhanced photocatalytic activity of sprayed Au doped ferric oxide thin films for salicylic acid degradation in aqueous medium.

    PubMed

    Mahadik, M A; Shinde, S S; Kumbhar, S S; Pathan, H M; Rajpure, K Y; Bhosale, C H

    2015-01-01

    Various doping percentage of Au were successfully introduced into the Fe2O3 photocatalysts via a spray pyrolysis method different. The effect of Au doping on photoelectrochemical, structural, optical and morphological properties of these deposited thin films is studied. The PEC characterization shows that, the photocurrent increases gradually with increasing Au content initially up to 2at.% indicating the maximum values of short circuit current (Isc) and open circuit voltage (Voc) are (Isc=90μA and Voc=220.5mV) and then decreases after exceeding the optimal Au doping content. Therefore, the photocurrent of Au doped Fe2O3 photocatalysts can be adjusted by the Au content. Deposited films are polycrystalline with a rhombohedral crystal structure having (104) preferred orientation. SEM and AFM images show deposited thin films are compact and uniform. The photocatalytic activities of the Fe2O3 and Au:Fe2O3 photocatalyst were evaluated by photoelectrocatalytic degradation of salicylic acid under sunlight irradiation. The results show that the Au:Fe2O3 thin film photocatalyst exhibited about 45% more degradation of pollutants than the pure Fe2O3. Thus, in Au doped Fe2O3 photocatalysts, the interaction between Au and Fe2O3 reduces the recombination of photogenerated charge carriers and improve the photocatalytic activity. PMID:25496876

  16. Enhanced anti-oxidative activity and lignocellulosic ethanol production by biotin addition to medium in Pichia guilliermondii fermentation.

    PubMed

    Qi, Kai; Xia, Xiao-Xia; Zhong, Jian-Jiang

    2015-01-01

    Commercialization of lignocellulosic ethanol fermentation requires its high titer, but the reactive oxygen species (ROS) accumulation during the bioprocess damaged the cells and compromised this goal. To improve the cellular anti-oxidative activity during non-detoxified corncob residue hydrolysate fermentation, seed cells were prepared to possess a higher level of intracellular biotin pool (IBP), which facilitated the biosyntheses of catalase and porphyrin. As a result, the catalase activity increased by 1.3-folds compared to control while the ROS level reduced by 50%. Cell viability in high-IBP cells was 1.7-folds of control and the final ethanol titer increased from 31.2 to 41.8 g L(-1) in batch fermentation. The high-IBP cells were further used for repeated-batch fermentation in the non-detoxified lignocellulosic hydrolysate, and the highest titer and average productivity of ethanol reached 63.7 g L(-1) and 1.2 g L(-1)h(-1). The results were favorable to future industrial application of this lignocellulosic bioethanol process. PMID:25864029

  17. Interaction of counterpropagating circularly polarized waves in an He--Ne ring laser with a gain greatly exceeding its losses

    SciTech Connect

    Mogil'naya, T.Y.; Savel'ev, I.I.; Timonin, P.V.; Yakushev, A.I.

    1983-10-01

    A theoretical and experimental investigation was made of the interaction between counterpropagating waves in an He--Ne ring laser having a circularly anisotropic resonator. This was done for large values of the ratio of the gain to the losses when the gain saturation was comparable with the gain itself. The dependences of the counterpropagating wave intensities and of the frequency of beats (formed when a longitudinal magnetic field was applied to the active medium) on the resonator detuning in a single-mode 0.63 ..mu.. wavelength laser were obtained experimentally. Numerically found theoretical dependences were in good agreement with experiment for values of the ratio of the gain to the losses of up to 2.9.

  18. [Current status of occupational health activities and the way that occupational health services should be offered to small- and medium-scale enterprises].

    PubMed

    Kayashima, Kotaro

    2013-10-01

    Activating occupational safety and health activities among Small- and Medium-scale Enterprises (SMEs) is a major issue because more than 80% of Japanese workers belong to these enterprises, in which the number of workers are less than 300 people. However, as the size of the enterprise decreases, the occurrence of problems of safety and health management systems and safety and health activities increases. Reasons for this include both the limitations of investments shortages of human resources. Occupational health services in SMEs has been provided by the cooperation of the following institutions: public associations (such as Regional Occupational Health Centers, Occupational Health Promotion Centers, Japan Industrial Safety and Health Association (JISHA)), occupational health agencies which provide checkup services, health insurance associations, and regional medical services. In contrast to the low coverage of occupational health services among SMEs in Japan, there are some countries in Europe in which this coverage is almost 100%. This is because of the development of occupational health services outside the company. To show the benefits of the safety and health activities to managers of SMEs, and to motivate them to take advantage of the services, it is important to consider measurements. Also, establishing systems that provide those services, improving the quality of specialists such as occupational physicians, and educating human resources, are all necessary. PMID:24107334

  19. Investigation of catalytic activity towards oxygen reduction reaction of Pt dispersed on boron doped graphene in acid medium.

    PubMed

    Pullamsetty, Ashok; Sundara, Ramaprabhu

    2016-10-01

    Boron doped graphene was prepared by a facile method and platinum (Pt) decoration over boron doped graphene was done in various chemical reduction methods such as sodium borohydride (NaBH4), polyol and modified polyol. X-ray diffraction analysis indicates that the synthesized catalyst particles are present in a nanocrystalline structure and transmission and scanning electron microscopy were employed to investigate the morphology and particle distribution. The electrochemical properties were investigated with the help of the rotating disk electrode (RDE) technique and cyclic voltammetry. The results show that the oxygen reduction reaction (ORR) takes place by a four-electron process. The kinetics of the ORR was evaluated using K-L and Tafel plots. The electrocatalyst obtained in modified polyol reduction method has shown the better catalytic activity compared to other two electrocatalysts. PMID:27393888

  20. Gas chromatographic determination of microamounts of glycols and their esters in aqueous medium using adsorption on activated charcoal

    SciTech Connect

    Begunov, G.A.; Titovskaya, V.N.; Galenko, A.V.

    1987-11-10

    Rapid growth of production of glycols and their derivatives, especially methyl and ethyl esters, and wide use of these substances in various branches of the national economy (1) inevitably necessitate analytical monitoring of their content in waste waters and various water bodies. The authors studied the scope of gas-chromatographic determination of microamounts of glycols and their esters in aqueous media at the sanitary standards level (10/sup -5/%) using activated charcoal for their adsorption concentration from aqueous solutions, desorption from the charcoal by ethanol, and evaporationconcentration of the alcoholic solutions. The quantitative concentration characteristics were studied with reference to ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethyleneglycol, tripropylene glycol, tetraethylene glycol, ethylcellosolve, ethyl carbitol, and monoethyl ester of triethylene glycol.

  1. Mars' upper atmosphere and ionosphere at low, medium, and high solar activities: Implications for evolution of water

    NASA Astrophysics Data System (ADS)

    Krasnopolsky, Vladimir A.

    2002-12-01

    Self-consistent models for 11 neutral and 18 ion species from 80 to 300 km on Mars have been developed by solving the continuity equations including ambipolar diffusion for ions. The models were calculated for the conditions of the HST, FUSE, and Mariner 6 and 7 observations of D, H2, and H, respectively, when the solar activity index was equal to 25, 61, and 88 at Mars orbit, respectively. Special care was taken to simulate the processes of H2 and HD dissociation in the reactions with CO2+, O+, CO+, N2+, N+, Ar+, and O(1D) and by photoelectrons. Thermal and nonthermal escape velocities were used as the upper boundary conditions for H2, H, HD, D, and He. The H2 and HD mixing ratios of 15 ppm and 11 ppb chosen to fit the FUSE and HST observations of H2 and D, respectively, result in (HD/H2)/(HDO/H2O) = 0.4. This value agrees with the depletion of D in H2 because of the smaller HDO photolysis cross section and the preferential condensation of HDO above the condensation level. Therefore the controversial problem of deuterium fractionation is solved throughout the atmosphere. The influx of cometary water was ~0.5 m planetwide in the last 3.8 billion years. It cannot affect the estimates of more than 30 m of water lost by sputtering and nonthermal and thermal escape and more than 1.3 km of water lost in the reaction with iron with subsequent hydrodynamic escape of H2. The calculated ion density profiles at various solar activity and the column reaction rates provide complete quantitative information for behavior of each ion, its formation, and its loss. The HCO+ ion is abundant in Mars' ionosphere because it is a final product of many reactions of other ions with H2 and does not react with neutral species.

  2. Prismatic louver active façades for natural illumination and thermal energy gain in high-rise and commercial buildings

    NASA Astrophysics Data System (ADS)

    Vlachokostas, A.; Volkmann, C.; Madamopoulos, N.

    2013-06-01

    High-rise and commercial buildings in urban centers present a great challenge in terms of their energy consumption. Due to maximization of rentable square footage, the preferred urban façade system over the past 50 years has been the "curtain wall", only a few inches thick and comprised of modular steel or aluminum framing and predominant glass infills. The perceived Achilles heel of these modern glass façade systems is their thermal inefficiency: They are inadequate thermal barriers and exhibit excessive solar gain. The excessive solar gain has a negative impact on lighting and cooling loads of the entire building. This negative impact will be further exacerbated with rising energy costs. However, rather than view the glass façade's uncontrolled solar gain merely as a weakness contributing to higher energy consumption, the condition could indeed be considered as related to an energy solution. These glass façades can be retrofitted to operate as a provider of daylight and energy for the rest of the building, taking advantage of the overexposure to the sun. With today's technology, the sun's abundant renewable energy can be the driving force for the energy transition of these building envelopes. Illumination, thermal energy, and electricity production can be directly supplied from the sun, and when correctly and efficiently managed, they can lead to a significantly less energy-intensive building stock. We propose a multi-purpose, prismatic, louver-based façade to perform both daylight and thermal energy harvesting with a goal of offering a better daylight environment for the occupants, and reduce the energy consumption and carbon footprint of the building. While decentralized air-conditioning units are commonly accepted as façade "plug-ins", such decentralization could be utilized with more benefits by passively managing the interior space conditions, without using any extra power. Just as living organisms respond and adapt to the environmental changes in

  3. FSH supplementation to culture medium is beneficial for activation and survival of preantral follicles enclosed in equine ovarian tissue.

    PubMed

    Aguiar, F L N; Lunardi, F O; Lima, L F; Rocha, R M P; Bruno, J B; Magalhães-Padilha, D M; Cibin, F W S; Nunes-Pinheiro, D C S; Gastal, M O; Rodrigues, A P R; Apgar, G A; Gastal, E L; Figueiredo, J R

    2016-04-01

    This study investigated the effect of adding different concentrations of bovine recombinant follicle-stimulating hormone on the IVC of equine preantral follicles enclosed in ovarian tissue fragments. Randomized ovarian fragments were fixed immediately (fresh noncultured control) or cultured for 1 or 7 days in α-MEM(+) supplemented with 0, 10, 50, and 100 ng/mL FSH and subsequently analyzed by classical histology. Culture media collected on Day 1 or Day 7 and were analyzed for steroids (estradiol and progesterone) and reactive oxygen species (ROS). After Day 1 and Day 7 of culture, 50-ng/mL FSH treatment had a greater (P < 0.05) percentage of morphologically normal follicles when compared to the other groups, except the 10-ng/mL FSH treatment at Day 1 of culture. The percentage of developing follicles (transition, primary, and secondary), and follicular and oocyte diameters were higher (P < 0.05) in the 50-ng/mL FSH treatment compared to the other groups after Day 7 of culture. Furthermore, estradiol secretion and ROS production were maintained (P > 0.05) throughout the culture in the 50-ng/mL FSH treatment. In conclusion, the addition of 50 ng/mL of FSH promoted activation of primordial follicles to developing follicles, improved survival of preantral follicles, and maintained estradiol and ROS production of equine ovarian tissue after 7 days of culture. PMID:26723132

  4. Large-scale jets from active galactic nuclei as a source of intracluster medium heating: cavities and shocks

    NASA Astrophysics Data System (ADS)

    Perucho, Manel; Martí, José-María; Quilis, Vicent; Ricciardelli, Elena

    2014-12-01

    The evolution of powerful extragalactic jets is not only interesting by itself, but also for its impact on the evolution of the host galaxy and its surroundings. We have performed long-term axisymmetric numerical simulations of relativistic jets with different powers to study their evolution through an environment with a pressure and density gradient. Our results show key differences in the evolution of jets with different powers in terms of the spatial and temporal scales of energy deposition. According to our results, the observed morphology in X-ray cavities requires that an important fraction of the jet's energetic budget is in the form of internal energy. Thus, light, lepton-dominated jets are favoured. In all cases, heating is mainly produced by shocks. Cavity overpressure is sustained by an important population of thermal particles. Our simulations reproduce the cool-core structure in projected, luminosity-weighted temperature. We have performed an additional simulation of a slow, massive jet and discuss the differences with its relativistic counterparts. Important qualitative and quantitative differences are found between the non-relativistic and the relativistic jets. Our conclusions point towards a dual mode of active galactic nuclei kinetic feedback, depending on the jet power.

  5. Polyester hydrolytic and synthetic activity catalyzed by the medium-chain-length poly(3-hydroxyalkanoate) depolymerase from Streptomyces venezuelae SO1.

    PubMed

    Santos, Marta; Gangoiti, Joana; Keul, Helmut; Möller, Martin; Serra, Juan L; Llama, María J

    2013-01-01

    The extracellular medium-chain-length polyhydroxyalkanote (MCL-PHA) depolymerase from an isolate identified as Streptomyces venezuelae SO1 was purified to electrophoretic homogeneity and characterized. The molecular mass and pI of the purified enzyme were approximately 27 kDa and 5.9, respectively. The depolymerase showed its maximum activity in the alkaline pH range and 50 °C and retained more than 70 % of its initial activity after 8 h at 40 °C. The MCL-PHA depolymerase hydrolyzes various p-nitrophenyl-alkanoates and polycaprolactone but not polylactide, poly-3-hydroxybutyrate, and polyethylene succinate. The enzymatic activity was markedly enhanced by the presence of low concentrations of detergents and organic solvents, being inhibited by dithiothreitol and EDTA. The potential of using the enzyme to produce (R)-3-hydroxyoctanoate in aqueous media or to catalyze ester-forming reactions in anhydrous media was investigated. In this sense, the MCL-PHA depolymerase catalyzes the hydrolysis of poly-3-hydroxyoctanoate to monomeric units and the ring-opening polymerization of β-butyrolactone and lactides, while ε-caprolactone and pentadecalactone were hardly polymerized. PMID:22695803

  6. Partially sulfated lime-fly ash sorbents activated by water or steam for SO{sub 2} removal at a medium temperature

    SciTech Connect

    Liming Shi; Xuchang Xu

    2005-12-01

    Laboratory experiments were conducted to investigate the reactivity of partially sulfated lime-fly ash sorbents activated by water or steam for SO{sub 2} removal. Sulfation tests were performed at 550{sup o}C using a fixed bed reactor under conditions simulating economizer zone injection flue gas desulfurization. Activation experiments were conducted with water or steam using a range of temperatures between 100 and 550{sup o}C. The results showed that the reactivity of the sorbents was closely related to the content of Ca(OH){sub 2} formed in the activation process, which varied with the water or steam temperature. The sulfur dioxide capture capacity of Ca(OH){sub 2} in the sorbent is higher than that of CaO at a medium temperature. Water or steam temperatures in the range of 100-200{sup o}C are favorable to the formation of Ca(OH){sub 2} from CaO. 15 refs., 8 figs., 2 tabs.

  7. Oscillations and uniaxial mechanochemical waves in a model of an active poroelastic medium: Application to deformation patterns in protoplasmic droplets of Physarum polycephalum

    NASA Astrophysics Data System (ADS)

    Alonso, Sergio; Strachauer, Ulrike; Radszuweit, Markus; Bär, Markus; Hauser, Marcus J. B.

    2016-04-01

    Self-organization in cells often manifests itself in oscillations and waves. Here, we address deformation waves in protoplasmic droplets of the plasmodial slime mould Physarum polycephalum by modelling and experiments. In particular, we extend a one-dimensional model that considered the cell as a poroelastic medium, where active tension caused mechanochemical waves that were regulated by an inhibitor (Radszuweit et al., 2013). Our extension consists of a simple, qualitative chemical reaction-diffusion model (Brusselator) that describes the regulation of the inhibitor by another biochemical species. The biochemical reaction enhances the formation of mechanochemical waves if the reaction rates and input concentrations are near or inside an oscillatory regime. The period of the waves is found to be controlled by the characteristic oscillation period, whereas their wavelength is set by mechanical parameters. The model also allows for a systematic study of the chemical activity at the onset of mechanochemical waves. We also present examples for pattern formation in protoplasmic droplets of Physarum polycephalum including global oscillations where the central region of the droplets is in antiphase to the boundary zone, as well as travelling and standing wave-like uniaxial patterns. Finally, we apply our model to reproduce these experimental results by identifying the active tension inhibitor with the intracellular calcium concentration in the Physarum droplets and by using parameter values from mechanical experiments, respectively knowledge about the properties of calcium oscillations in Physarum. The simulation results are then found to be in good agreement with the experimental observations.

  8. Central Gain Control in Tinnitus and Hyperacusis

    PubMed Central

    Auerbach, Benjamin D.; Rodrigues, Paulo V.; Salvi, Richard J.

    2014-01-01

    Sensorineural hearing loss induced by noise or ototoxic drug exposure reduces the neural activity transmitted from the cochlea to the central auditory system. Despite a reduced cochlear output, neural activity from more central auditory structures is paradoxically enhanced at suprathreshold intensities. This compensatory increase in the central auditory activity in response to the loss of sensory input is referred to as central gain enhancement. Enhanced central gain is hypothesized to be a potential mechanism that gives rise to hyperacusis and tinnitus, two debilitating auditory perceptual disorders that afflict millions of individuals. This review will examine the evidence for gain enhancement in the central auditory system in response to cochlear damage. Further, it will address the potential cellular and molecular mechanisms underlying this enhancement and discuss the contribution of central gain enhancement to tinnitus and hyperacusis. Current evidence suggests that multiple mechanisms with distinct temporal and spectral profiles are likely to contribute to central gain enhancement. Dissecting the contributions of these different mechanisms at different levels of the central auditory system is essential for elucidating the role of central gain enhancement in tinnitus and hyperacusis and, most importantly, the development of novel treatments for these disorders. PMID:25386157

  9. Antimicrobial activity of Hibiscus sabdariffa aqueous extracts against Escherichia coli O157:H7 and Staphylococcus aureus in a microbiological medium and milk of various fat concentrations.

    PubMed

    Higginbotham, Kristen L; Burris, Kellie P; Zivanovic, Svetlana; Davidson, P Michael; Stewart, C Neal

    2014-02-01

    Hibiscus sabdariffa L. calyces are widely used in the preparation of beverages. The calyces contain compounds that exhibit antimicrobial activity, yet little research has been conducted on their possible use in food systems as antimicrobials. Aqueous extracts prepared from the brand "Mi Costenita" were sterilized by membrane filtration (0.22-μm pore size) or autoclaving (121 °C, 30 min) and tested for antimicrobial activity against the foodborne pathogens Escherichia coli O157:H7 strains ATCC 43894 and Cider and Staphylococcus aureus strains SA113 and ATCC 27708 in a microbiological medium and ultrahigh-temperature-processed milk with various fat percentages. Extracts heated by autoclaving exhibited greater activity than did filtered extracts in a microbiological medium. Against E. coli, results of 20 mg/ml filtered extract were not different from those of the control, whereas autoclaved extracts reduced viable cells ca. 3 to 4 log CFU/ml. At 60 mg/ml, both extracts inactivated cells after 24 h. There were reduced populations of both strains of S. aureus (ca. 2.7 and 3 log CFU/ml, respectively) after 24 h of incubation in 40 mg/ml filtered extracts. When grown in autoclaved extracts at 40 mg/ml, both strains of S. aureus were inactivated after 9 h. Autoclaved extracts had decreased anthocyanin content (2.63 mg/liter) compared with filtered extracts (14.27 mg/liter), whereas the phenolic content (48.7 and 53.8 mg/g) remained similar for both treatments. Autoclaved extracts were then tested for activity in milk at various fat concentrations (skim [<0.5%], 1%, 2%, and whole [>3.25%]) against a 1:1 mixture of the two strains of E. coli O157:H7 and a 1:1 mixture of the two strains of S. aureus. Extracts at 40 mg/ml inactivated S. aureus after 168 h in skim and whole milk, and E. coli was inactivated after 96 h in 60 mg/ml extract in all fat levels. These findings show the potential use of Hibiscus extracts to prevent the growth of pathogens in foods and beverages

  10. The STAT3 HIES mutation is a gain-of-function mutation that activates genes via AGG-element carrying promoters.

    PubMed

    Xu, Li; Ji, Jin-Jun; Le, Wangping; Xu, Yan S; Dou, Dandan; Pan, Jieli; Jiao, Yifeng; Zhong, Tianfei; Wu, Dehong; Wang, Yumei; Wen, Chengping; Xie, Guan-Qun; Yao, Feng; Zhao, Heng; Fan, Yong-Sheng; Chin, Y Eugene

    2015-10-15

    Cytokine or growth factor activated STAT3 undergoes multiple post-translational modifications, dimerization and translocation into nuclei, where it binds to serum-inducible element (SIE, 'TTC(N3)GAA')-bearing promoters to activate transcription. The STAT3 DNA binding domain (DBD, 320-494) mutation in hyper immunoglobulin E syndrome (HIES), called the HIES mutation (R382Q, R382W or V463Δ), which elevates IgE synthesis, inhibits SIE binding activity and sensitizes genes such as TNF-α for expression. However, the mechanism by which the HIES mutation sensitizes STAT3 in gene induction remains elusive. Here, we report that STAT3 binds directly to the AGG-element with the consensus sequence 'AGG(N3)AGG'. Surprisingly, the helical N-terminal region (1-355), rather than the canonical STAT3 DBD, is responsible for AGG-element binding. The HIES mutation markedly enhances STAT3 AGG-element binding and AGG-promoter activation activity. Thus, STAT3 is a dual specificity transcription factor that promotes gene expression not only via SIE- but also AGG-promoter activity. PMID:26384563

  11. Analytic study of the chain dark decomposition reaction of iodides - atomic iodine donors - in the active medium of a pulsed chemical oxygen-iodine laser: 2. Limiting parameters of the branching chain dark decomposition reaction of iodides

    SciTech Connect

    Andreeva, Tamara L; Kuznetsova, S V; Maslov, Aleksandr I; Sorokin, Vadim N

    2009-08-31

    The final stages in the development of a branching chain decomposition reaction of iodide in the active medium of a pulsed chemical oxygen-iodine laser (COIL) are analysed. Approximate expressions are derived to calculate the limiting parameters of the chain reaction: the final degree of iodide decomposition, the maximum concentration of excited iodine atoms, the time of its achievement, and concentrations of singlet oxygen and iodide at that moment. The limiting parameters, calculated by using these expressions for a typical composition of the active medium of a pulsed COIL, well coincide with the results of numerical calculations. (active media)

  12. Teacher-and Child-Managed Academic Activities in Preschool and Kindergarten and Their Influence on Children's Gains in Emergent Academic Skills

    ERIC Educational Resources Information Center

    de Haan, Annika K. E.; Elbers, Ed; Leseman, Paul P. M.

    2014-01-01

    The aim of this study was to assess whether children's development benefited from teacher-and child-managed academic activities in the preschool and kindergarten classroom. Extensive systematic observations during four half-days in preschool ("n"?=?8) and kindergarten ("n"?=?8) classrooms revealed that classrooms differed…

  13. Cochlear gain control

    NASA Astrophysics Data System (ADS)

    van der Heijden, Marcel

    2005-03-01

    The nonlinear auditory phenomena of compression, suppression, and distortion are known to have a cochlear-mechanical origin. An instantaneous nonlinear transfer function is often assumed to underlie these phenomena, but there are experimental indications that auditory nonlinearity is sluggish rather than instantaneous. This study analyzes the consequences of such sluggishness, using automatic gain control (AGC) as a model noninstantaneous nonlinearity. The distinctive characteristic of AGC, its delayed action, is shown to produce a number of observable and measurable effects that distinguish AGC from instantaneous nonlinearities. A major class of such AGC-specific effects concerns the phase of aural distortion products. For example, the phase of the cancellation tone in the classical psychoacoustic cancellation paradigm is linearly related to the frequency spacing of the primary tones in an AGC, as opposed to the square-law relationship produced by an instantaneous nonlinearity. These and other predictions are confronted with experimental data from the literature. The impact of putative AGC-related delays on the interpretation of distortion product otoacoustic emissions (DPOAEs) is discussed. Detailed suggestions are made for experiments specifically aimed at determining whether cochlear nonlinearity is instantaneous or delayed. .

  14. Managing price, gaining profit.

    PubMed

    Marn, M V; Rosiello, R L

    1992-01-01

    The fastest and most effective way for a company to realize maximum profit is to get its pricing right. The right price can boost profit faster than increasing volume will; the wrong price can shrink it just as quickly. Yet many otherwise tough-minded managers miss out on significant profits because they shy away from pricing decisions for fear that they will alienate their customers. Worse, if management isn't controlling its pricing policies, there's a good chance that the company's clients are manipulating them to their own advantage. McKinsey & Company's Michael Marn and Robert Rosiello show managers how to gain control of the pricing puzzle and capture untapped profit potential by using two basic concepts: the pocket price waterfall and the pocket price band. The pocket price waterfall reveals how price erodes between a company's invoice figure and the actual amount paid by the customer--the transaction price. It tracks the volume purchase discounts, early payment bonuses, and frequent customer incentives that squeeze a company's profits. The pocket price band plots the range of pocket prices over which any given unit volume of a single product sells. Wide price bands are commonplace: some manufacturers' transaction prices for a given product range 60%; one fastener supplier's price band ranged up to 500%. Managers who study their pocket price waterfalls and bands can identify unnecessary discounting at the transaction level, low-performance accounts, and misplaced marketing efforts. The problems, once identified, are typically easy and inexpensive to remedy. PMID:10121318

  15. Opposite Effects of mGluR1a and mGluR5 Activation on Nucleus Accumbens Medium Spiny Neuron Dendritic Spine Density.

    PubMed

    Gross, Kellie S; Brandner, Dieter D; Martinez, Luis A; Olive, M Foster; Meisel, Robert L; Mermelstein, Paul G

    2016-01-01

    The group I metabotropic glutamate receptors (mGluR1a and mGluR5) are important modulators of neuronal structure and function. Although these receptors share common signaling pathways, they are capable of having distinct effects on cellular plasticity. We investigated the individual effects of mGluR1a or mGluR5 activation on dendritic spine density in medium spiny neurons in the nucleus accumbens (NAc), which has become relevant with the potential use of group I mGluR based therapeutics in the treatment of drug addiction. We found that systemic administration of mGluR subtype-specific positive allosteric modulators had opposite effects on dendritic spine densities. Specifically, mGluR5 positive modulation decreased dendritic spine densities in the NAc shell and core, but was without effect in the dorsal striatum, whereas increased spine densities in the NAc were observed with mGluR1a positive modulation. Additionally, direct activation of mGluR5 via CHPG administration into the NAc also decreased the density of dendritic spines. These data provide insight on the ability of group I mGluRs to induce structural plasticity in the NAc and demonstrate that the group I mGluRs are capable of producing not just distinct, but opposing, effects on dendritic spine density. PMID:27618534

  16. Modelling of effects of water activity and temperature on germination and growth of ochratoxigenic isolates of Aspergillus ochraceus on a green coffee-based medium.

    PubMed

    Pardo, E; Ramos, A J; Sanchis, V; Marín, S

    2005-01-15

    Influence of water activity (0.75-0.99 a(w)) and temperature (10, 20 and 30 degrees C) on germination and mycelial growth on green coffee extract agar medium of three ochratoxigenic isolates of Aspergillus ochraceus was studied. Optimal conditions for germination and growth were observed at 0.95-0.99 a(w) and 20-30 degrees C for the three isolates. Minimum a(w) level for germination was 0.80, and 0.85 for mycelial growth. At marginal a(w) and temperature levels assayed, the lag phases prior to germination increased and the growth rates showed a significant decrease in comparison with the optimal conditions. Data were modelled by a multiple linear regression (MLR) and response surface models were obtained. Germination and growth of A. ochraceus in green coffee beans could be prevented or at least inhibited to some extent by minimising the time that coffee beans are exposed to temperature and humidity conditions near to the optimum during processing and storage. This could be an empirical approach to predict the effects of water activity and temperature conditions on the development of ochratoxigenic isolates of A. ochraceus during handling and storage of green coffee. PMID:15617796

  17. Selective expression of a dominant-negative type Iα PKA regulatory subunit in striatal medium spiny neurons impairs gene expression and leads to reduced feeding and locomotor activity.

    PubMed

    Yang, Linghai; Gilbert, Merle L; Zheng, Ruimao; McKnight, G Stanley

    2014-04-01

    Striatal medium spiny neurons (MSNs) mediate many of the physiological effects of dopamine, including the regulation of feeding and motor behaviors. Dopaminergic inputs from the midbrain modulate MSN excitability through pathways that involve cAMP and protein kinase A (PKA), but the physiological role of specific PKA isoforms in MSN neurons remains poorly understood. One of the major PKA regulatory (R) subunit isoforms expressed in MSNs is RIIβ, which localizes the PKA holoenzyme primarily to dendrites by interaction with AKAP5 and other scaffolding proteins. However, RI (RIα and RIβ) subunits are also expressed in MSNs and the RI holoenzyme has a weaker affinity for most scaffolding proteins and tends to localize in the cell body. We generated mice with selective expression of a dominant-negative RI subunit (RIαB) in striatal MSNs and show that this dominant-negative RIαB localizes to the cytoplasm and specifically inhibits type I PKA activity in the striatum. These mice are normal at birth; however, soon after weaning they exhibit growth retardation and the adult mice are hypophagic, lean, and resistant to high-fat diet-induced hyperphagia and obesity. The RIαB-expressing mice also exhibit decreased locomotor activity and decreased dopamine-regulated CREB phosphorylation and c-fos gene expression in the striatum. Our results demonstrate a critical role for cytoplasmic RI-PKA holoenzyme in gene regulation and the overall physiological function of MSNs. PMID:24695708

  18. Red, green, and blue lasing enabled by single-exciton gain in colloidal quantum dot films

    DOEpatents

    Nurmikko, Arto V.; Dang, Cuong

    2016-06-21

    The methods and materials described herein contemplate the use films of colloidal quantum dots as a gain medium in a vertical-cavity surface-emitting laser. The present disclosure demonstrates a laser with single-exciton gain in the red, green, and blue wavelengths. Leveraging this nanocomposite gain, the results realize a significant step toward full-color single-material lasers.

  19. On Comparing Transition Rate Gains.

    ERIC Educational Resources Information Center

    Reuterberg, Sven-Eric

    This report is about the problem of making transition or enrollment rate gains comparable. It is shown that measures based on the proportions themselves, i.e. the difference between proportions, the proportion ratio and the residual gain ratio do not make the gains comparable. Instead a non-linear transformation has to be done. Two such…

  20. Should I Gain Weight?

    MedlinePlus

    ... of moderate to vigorous physical activity every day. Strength training , when done safely, is a healthy way to ... you've hit puberty, the right amount of strength training will help your muscles become stronger and have ...

  1. Airflow models gaining clout

    SciTech Connect

    Post, N.M.

    1994-10-10

    Move over, mock-ups. So long, smoke bombs. Take a walk, wind tunnels. Computational fluid dynamics, a spaceage simulation technique, is gaining velocity in the building community. And the design of inner spaces may never be the same. CFD is an equation-intensive computer modeling method that can simulate transient and steady-state airflow patterns and temperature gradients, indoors or out. CFD is used to downsize heating, ventilating and air conditioning systems, locate air outlets, and in general, create spaces that offer creature comfort, provide quality air and use less energy. The method is good for new construction, retrofits and forensic work, for example to investigate a building fire or a contaminant. In a room, CFD helps engineers consider, over a period of time, the combined impacts of ventilation, size, shape, contents, weather, even fenestration. For its first decade or two, CFD stayed the near-exclusive domain of aerospace, defense and electronics. With few exceptions, the building community could not afford the supercomputers that were needed to run the tens of thousands of equations involved. However, in the past few years, thanks to the increasing power and decreasing cost of computers, CFD simulation became practical. Curtain wall designers are even using it, though not without some controversy. Indoor air quality specialists, smoke and fire-spread researchers, laboratory designers, energy engineers, code writers, architects, and plant and building engineers are uncharacteristically upbeat about the tool. {open_quotes}CFD modeling is so many light years ahead of design tools that exist,{close_quotes} says Mariano Rodriguez, director of research and development for architect The Hillier Group, Princeton, N.J. {open_quotes}It`s the next step up from a wind tunnel test, and you don`t need a $300,000 wind tunnel.{close_quotes}

  2. Optical gain in Coumarin 545T-doped Tris(8-hydroxy-chinolinato)aluminium thin films

    NASA Astrophysics Data System (ADS)

    Rabe, T.; Görrn, P.; Riedl, T.; Kowalsky, W.

    2007-09-01

    In this paper we investigate the optical gain in organic thin film waveguides using the variable stripe length method (VSL). As active medium the guest-host system containing Tris-(8-hydroxy-chinolinato)-aluminium (Alq3) doped by 10-(2-benzothiazolyl)-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H,11H- (1)-benzopyropyrano- (6,7-8-i,j)quinolizin-11-one (C545T) is studied. The doping concentration is varied over a wide range and the gain coefficient is measured at different excitation densities to analyze the behavior of the differential gain. The F¨orster energy transfer is responsible for the occupation of the exited state of the coumarin molecules. For low doping concentrations with an inefficient host-guest energy transfer a low stimulated cross section can be observed. At optimal doping concentrations (3.7-6.4 wt%) we obtain a cross section of σ =6.8x10 -17 cm2 and a high material gain of g mat ~500 cm -1 at an excitation density E ex of E ex ~300 μJ/cm2. A further increased doping concentration (15 wt%) leads to a reduced cross section, due the onset of concentration quenching in the guest-host system. Furthermore, at high excitation densities we observe a strong saturation effect of the maximum gain which depends strongly on the doping concentration.

  3. Transcriptional responses to loss or gain of function of the leucine-rich repeat kinase 2 (LRRK2) gene uncover biological processes modulated by LRRK2 activity

    PubMed Central

    Nikonova, Elena V.; Xiong, Yulan; Tanis, Keith Q.; Dawson, Valina L.; Vogel, Robert L.; Finney, Eva M.; Stone, David J.; Reynolds, Ian J.; Kern, Jonathan T.; Dawson, Ted M.

    2012-01-01

    Mutations in the leucine-rich repeat kinase 2 gene (LRRK2) are the most common genetic cause of Parkinson's disease (PD) and cause both autosomal dominant familial and sporadic PD. Currently, the physiological and pathogenic activities of LRRK2 are poorly understood. To decipher the biological functions of LRRK2, including the genes and pathways modulated by LRRK2 kinase activity in vivo, we assayed genome-wide mRNA expression in the brain and peripheral tissues from LRRK2 knockout (KO) and kinase hyperactive G2019S (G2019S) transgenic mice. Subtle but significant differences in mRNA expression were observed relative to wild-type (WT) controls in the cortex, striatum and kidney of KO animals, but only in the striatum in the G2019S model. In contrast, robust, consistent and highly significant differences were identified by the direct comparison of KO and G2019S profiles in the cortex, striatum, kidney and muscle, indicating opposite effects on mRNA expression by the two models relative to WT. Ribosomal and glycolytic biological functions were consistently and significantly up-regulated in LRRK2 G2019S compared with LRRK2 KO tissues. Genes involved in membrane-bound organelles, oxidative phosphorylation, mRNA processing and the endoplasmic reticulum were down-regulated in LRRK2 G2019S mice compared with KO. We confirmed the expression patterns of 35 LRRK2-regulated genes using quantitative reverse transcription polymerase chain reaction. These findings provide the first description of the transcriptional responses to genetically modified LRRK2 activity and provide preclinical target engagement and/or pharmacodynamic biomarker strategies for LRRK2 and may inform future therapeutic strategies for LRRK2-associated PD. PMID:21972245

  4. Reducing gain shifts in photomultiplier tubes

    DOEpatents

    Cohn, Charles E.

    1976-01-01

    A means is provided for reducing gain shifts in multiplier tubes due to varying event count rates. It includes means for limiting the number of cascaded, active dynodes of the multiplier tube to a predetermined number with the last of predetermined number of dynodes being the output terminal of the tube. This output is applied to an amplifier to make up for the gain sacrificed by not totally utilizing all available active stages of the tube. Further reduction is obtained by illuminating the predetermined number of dynodes with a light source of such intensity that noise appearing at the output dynode associated with the illumination is negligible.

  5. Identification of Candidate Agents Active against N. ceranae Infection in Honey Bees: Establishment of a Medium Throughput Screening Assay Based on N. ceranae Infected Cultured Cells

    PubMed Central

    Gisder, Sebastian; Genersch, Elke

    2015-01-01

    Many flowering plants in both natural ecosytems and agriculture are dependent on insect pollination for fruit set and seed production. Managed honey bees (Apis mellifera) and wild bees are key pollinators providing this indispensable eco- and agrosystem service. Like all other organisms, bees are attacked by numerous pathogens and parasites. Nosema apis is a honey bee pathogenic microsporidium which is widely distributed in honey bee populations without causing much harm. Its congener Nosema ceranae was originally described as pathogen of the Eastern honey bee (Apis cerana) but jumped host from A. cerana to A. mellifera about 20 years ago and spilled over from A. mellifera to Bombus spp. quite recently. N. ceranae is now considered a deadly emerging parasite of both Western honey bees and bumblebees. Hence, novel and sustainable treatment strategies against N. ceranae are urgently needed to protect honey and wild bees. We here present the development of an in vitro medium throughput screening assay for the identification of candidate agents active against N. ceranae infections. This novel assay is based on our recently developed cell culture model for N. ceranae and coupled with an RT-PCR-ELISA protocol for quantification of N. ceranae in infected cells. The assay has been adapted to the 96-well microplate format to allow automated analysis. Several substances with known (fumagillin) or presumed (surfactin) or no (paromomycin) activity against N. ceranae were tested as well as substances for which no data concerning N. ceranae inhibition existed. While fumagillin and two nitroimidazoles (metronidazole, tinidazole) totally inhibited N. ceranae proliferation, all other test substances were inactive. In summary, the assay proved suitable for substance screening and demonstrated the activity of two synthetic antibiotics against N. ceranae. PMID:25658121

  6. Identification of candidate agents active against N. ceranae infection in honey bees: establishment of a medium throughput screening assay based on N. ceranae infected cultured cells.

    PubMed

    Gisder, Sebastian; Genersch, Elke

    2015-01-01

    Many flowering plants in both natural ecosytems and agriculture are dependent on insect pollination for fruit set and seed production. Managed honey bees (Apis mellifera) and wild bees are key pollinators providing this indispensable eco- and agrosystem service. Like all other organisms, bees are attacked by numerous pathogens and parasites. Nosema apis is a honey bee pathogenic microsporidium which is widely distributed in honey bee populations without causing much harm. Its congener Nosema ceranae was originally described as pathogen of the Eastern honey bee (Apis cerana) but jumped host from A. cerana to A. mellifera about 20 years ago and spilled over from A. mellifera to Bombus spp. quite recently. N. ceranae is now considered a deadly emerging parasite of both Western honey bees and bumblebees. Hence, novel and sustainable treatment strategies against N. ceranae are urgently needed to protect honey and wild bees. We here present the development of an in vitro medium throughput screening assay for the identification of candidate agents active against N. ceranae infections. This novel assay is based on our recently developed cell culture model for N. ceranae and coupled with an RT-PCR-ELISA protocol for quantification of N. ceranae in infected cells. The assay has been adapted to the 96-well microplate format to allow automated analysis. Several substances with known (fumagillin) or presumed (surfactin) or no (paromomycin) activity against N. ceranae were tested as well as substances for which no data concerning N. ceranae inhibition existed. While fumagillin and two nitroimidazoles (metronidazole, tinidazole) totally inhibited N. ceranae proliferation, all other test substances were inactive. In summary, the assay proved suitable for substance screening and demonstrated the activity of two synthetic antibiotics against N. ceranae. PMID:25658121

  7. Symmetry breaking and multipeaked solitons in inhomogeneous gain landscapes

    SciTech Connect

    Kartashov, Yaroslav V.; Vysloukh, Victor A.; Konotop, Vladimir V.

    2011-04-15

    We address one-dimensional soliton formation in a cubic nonlinear medium with two-photon absorption and transversally inhomogeneous gain landscape consisting of a single or several amplifying channels. Existence of the solitons requires certain threshold gain while the properties of solitons strongly depend on whether the number of the amplifying channels is odd or even. In the former case, an increase of the gain leads to symmetry breaking, which occurs through the pitchfork bifurcation, and to emergence of a single or several coexisting stable asymmetric modes. In the case of an even number of amplifying channels, we have found only asymmetric stable states.

  8. Fast gain and phase recovery of semiconductor optical amplifiers based on submonolayer quantum dots

    SciTech Connect

    Herzog, Bastian Owschimikow, Nina; Kaptan, Yücel; Kolarczik, Mirco; Switaiski, Thomas; Woggon, Ulrike; Schulze, Jan-Hindrik; Rosales, Ricardo; Strittmatter, André; Bimberg, Dieter; Pohl, Udo W.

    2015-11-16

    Submonolayer quantum dots as active medium in opto-electronic devices promise to combine the high density of states of quantum wells with the fast recovery dynamics of self-assembled quantum dots. We investigate the gain and phase recovery dynamics of a semiconductor optical amplifier based on InAs submonolayer quantum dots in the regime of linear operation by one- and two-color heterodyne pump-probe spectroscopy. We find an as fast recovery dynamics as for quantum dot-in-a-well structures, reaching 2 ps at moderate injection currents. The effective quantum well embedding the submonolayer quantum dots acts as a fast and efficient carrier reservoir.

  9. Glycolytic enzyme activity is essential for domestic cat (Felis catus) and cheetah (Acinonyx jubatus) sperm motility and viability in a sugar-free medium.

    PubMed

    Terrell, Kimberly A; Wildt, David E; Anthony, Nicola M; Bavister, Barry D; Leibo, S P; Penfold, Linda M; Marker, Laurie L; Crosier, Adrienne E

    2011-06-01

    We have previously reported a lack of glucose uptake in domestic cat and cheetah spermatozoa, despite observing that these cells produce lactate at rates that correlate positively with sperm function. To elucidate the role of glycolysis in felid sperm energy production, we conducted a comparative study in the domestic cat and cheetah, with the hypothesis that sperm motility and viability are maintained in both species in the absence of glycolytic metabolism and are fueled by endogenous substrates. Washed ejaculates were incubated in chemically defined medium in the presence/absence of glucose and pyruvate. A second set of ejaculates was exposed to a chemical inhibitor of either lactate dehydrogenase (sodium oxamate) or glyceraldehyde-3-phosphate dehydrogenase (alpha-chlorohydrin). Sperm function (motility and acrosomal integrity) and lactate production were assessed, and a subset of spermatozoa was assayed for intracellular glycogen. In both the cat and cheetah, sperm function was maintained without exogenous substrates and following lactate dehydrogenase inhibition. Lactate production occurred in the absence of exogenous hexoses, but only if pyruvate was present. Intracellular glycogen was not detected in spermatozoa from either species. Unexpectedly, glycolytic inhibition by alpha-chlorohydrin resulted in an immediate decline in sperm motility, particularly in the domestic cat. Collectively, our findings reveal an essential role of the glycolytic pathway in felid spermatozoa that is unrelated to hexose metabolism or lactate formation. Instead, glycolytic enzyme activity could be required for the metabolism of endogenous lipid-derived glycerol, with fatty acid oxidation providing the primary energy source in felid spermatozoa. PMID:21325689

  10. Electrocatalytic oxidation of ethanol in acid medium: Enhancement of activity of vulcan-supported Platinum-based nanoparticles upon immobilization within nanostructured zirconia matrices

    NASA Astrophysics Data System (ADS)

    Rutkowska, Iwona A.; Kulesza, Pawel J.

    2014-09-01

    Composite electrocatalytic materials that utilize carbon (Vulcan) supported Pt or PtRu nanoparticles dispersed within thin films of zirconia (ZrO2) are considered here for oxidation of such a biofuel as ethanol in acid medium. The systems were characterized using electrochemical techniques as well as transmission electron microscopy. The enhancement of activity was clearly evident upon comparison of the respective voltammetric and chronoamperometric current densities recorded (at room temperature in 0.5 mol dm-3H2SO4 containing 0.5 mol dm-3 ethanol) using the Vulcan supported Pt and PtRu catalysts in the presence and absence of zirconia. In all cases, the noble metal loading was the same, 100 μg cm-2. Apparently, the existence of large population of hydroxyl groups (originating from zirconia) in the vicinity of Pt-based catalyst, in addition to possible specific interactions between zirconia and the ruthenium component of PtRu, facilitated the oxidative removal (from Pt) of the passivating (e.g., CO) reaction intermediates (adsorbates). By utilizing carbon supported, rather than bare or unsupported, Pt or PtRu nanoparticles (dispersed within the semiconducting zirconia), the overall charge distribution at the electrocatalytic interface was improved.

  11. Economic Optimized Medium for Tensio-Active Agent Production by Candida sphaerica UCP0995 and Application in the Removal of Hydrophobic Contaminant from Sand

    PubMed Central

    Luna, Juliana M.; Rufino, Raquel D.; Albuquerque, Clarissa D.C.; Sarubbo, Leonie A.; Campos-Takaki, Galba M.

    2011-01-01

    Statistical experimental designs and response surface methodology were employed to optimize the concentrations of agroindustrial residues as soybean oil (SORR) from refinery, and corn steep liquor (CSL) from corn industry, for tensio-active agent produced by Candida sphaerica UCP 0995. Three 22 full factorial design were applied sequentially to investigate the effects of the concentrations and interactions of soybean oil refinery residue and corn steep liquor on the surface tension of free-cell culture broth for 144 h. Two 22 central composite designs and response surface methodology were adopted to derive a statistical model to measure the effect of SORR and CSL on the surface tension of the free-cell culture broth for 144 h. The regression equation obtained from the experimental data using a central composite design was solved, and by analyzing the response surface contour plots, the optimal concentrations of the constituents of the medium were determined: 8.63% v/v (≅9% v/v) of SORR and 8.80% v/v (≅9% v/v) CSL. The minimum surface tension predicted and experimentally confirmed was 25.25 mN/m. The new biosurfactant, denominated Lunasan, recovered 95% of motor oil adsorbed in a sand sample, thus showing great potential for use in bioremediation processes, especially in the petroleum industry. PMID:21731452

  12. emGain: Determination of EM gain of CCD

    NASA Astrophysics Data System (ADS)

    Daigle, Olivier; Carignan, Claude; Blais-Ouellette, Sebastien

    2012-01-01

    The determination of the EM gain of the CCD is best done by fitting the histogram of many low-light frames. Typically, the dark+CIC noise of a 30ms frame itself is a sufficient amount of signal to determine accurately the EM gain with about 200 512x512 frames. The IDL code emGain takes as an input a cube of frames and fit the histogram of all the pixels with the EM stage output probability function. The function returns the EM gain of the frames as well as the read-out noise and the mean signal level of the frames.

  13. Segregation and crosstalk of D1 receptor-mediated activation of ERK in striatal medium spiny neurons upon acute administration of psychostimulants.

    PubMed

    Gutierrez-Arenas, Omar; Eriksson, Olivia; Kotaleski, Jeanette Hellgren

    2014-01-01

    The convergence of corticostriatal glutamate and dopamine from the midbrain in the striatal medium spiny neurons (MSN) triggers synaptic plasticity that underlies reinforcement learning and pathological conditions such as psychostimulant addiction. The increase in striatal dopamine produced by the acute administration of psychostimulants has been found to activate not only effectors of the AC5/cAMP/PKA signaling cascade such as GluR1, but also effectors of the NMDAR/Ca(2+)/RAS cascade such as ERK. The dopamine-triggered effects on both these cascades are mediated by D1R coupled to Golf but while the phosphorylation of GluR1 is affected by reductions in the available amount of Golf but not of D1R, the activation of ERK follows the opposite pattern. This segregation is puzzling considering that D1R-induced Golf activation monotonically increases with DA and that there is crosstalk from the AC5/cAMP/PKA cascade to the NMDAR/Ca(2+)/RAS cascade via a STEP (a tyrosine phosphatase). In this work, we developed a signaling model which accounts for this segregation based on the assumption that a common pool of D1R and Golf is distributed in two D1R/Golf signaling compartments. This model integrates a relatively large amount of experimental data for neurons in vivo and in vitro. We used it to explore the crosstalk topologies under which the sensitivities of the AC5/cAMP/PKA signaling cascade to reductions in D1R or Golf are transferred or not to the activation of ERK. We found that the sequestration of STEP by its substrate ERK together with the insensitivity of STEP activity on targets upstream of ERK (i.e. Fyn and NR2B) to PKA phosphorylation are able to explain the experimentally observed segregation. This model provides a quantitative framework for simulation based experiments to study signaling required for long term potentiation in MSNs. PMID:24499932

  14. Giant energy gain in a pulsed HF laser based on a photon-branched chain reaction

    NASA Astrophysics Data System (ADS)

    Letfullin, Renat R.; Arnoldus, Henk F.; Foley, John T.

    2003-06-01

    A huge energy gain is predicted theoretically in a pulsed chemical laser-amplifier based on a photon-branched chain reaction initiated in a gaseous dispersed medium composed of H2-F2-O2-He and Al particles by focused external infrared radiation. It is shown that this effect is due to the possibility of ignition of the laser-chemical reaction in an initial small focal volume of the active medium. It then spreads out of this minimal volume spontaneously in the auto-wave regime without external power sources and subsequently fills the entire volume of the laser cavity with a high intensive electromagnetic field as self-supporting cylindrical photon-branching zones formed by the paths of the rays inside the unstable telescopic cavity. Calculations show that the ignition of an auto-wave photon-branched chain reaction under the condition of external signal focusing reduces strongly the input pulse energy necessary for initiation up to ~ 10-8 J, and thereby allows a huge value of the energy gain of ~ 1011. The predicted effect of this huge laser energy gain should make it possible to construct a self-contained laser, which can be initiated by a very weak source signal.

  15. Gain-assisted transformation optics.

    PubMed

    Han, Tiancheng; Qiu, Cheng-Wei; Hao, Jiaming; Tang, Xiaohong; Zouhdi, Said

    2011-04-25

    Loss severely degrades the cloaking effect of the device designed by traditional transformation. In this letter, we propose gain-assisted transformation optics to overcome the loss problem by introducing gain media into a spherical cloak. The gain media, which can amplify the electromagnetic fields, is controlled precisely to compensate the inherent loss in experimental realization of cloaks. We discuss the significance of controlling embedded gain materials in the context of the inverse design mechanism, which allows us to wisely select realizable materials with constant gain and loss along the radius. For practical realizations, isotropic spherical gain-assisted cloak is designed. Full-wave simulations validate the proposed design concept, which can be utilized to alleviate the inevitable loss problem in transformational optical devices. PMID:21643112

  16. Changing the Spatial Scope of Attention Alters Patterns of Neural Gain in Human Cortex

    PubMed Central

    Garcia, Javier O.; Rungratsameetaweemana, Nuttida; Sprague, Thomas C.

    2014-01-01

    Over the last several decades, spatial attention has been shown to influence the activity of neurons in visual cortex in various ways. These conflicting observations have inspired competing models to account for the influence of attention on perception and behavior. Here, we used electroencephalography (EEG) to assess steady-state visual evoked potentials (SSVEP) in human subjects and showed that highly focused spatial attention primarily enhanced neural responses to high-contrast stimuli (response gain), whereas distributed attention primarily enhanced responses to medium-contrast stimuli (contrast gain). Together, these data suggest that different patterns of neural modulation do not reflect fundamentally different neural mechanisms, but instead reflect changes in the spatial extent of attention. PMID:24381272

  17. Using of Teleconference as a Medium to Establish an "E-Global-Learning-System": An Experience of 1000guru-Association on Facilitates Open and Distance Learning Activities with Schools in Indonesia

    ERIC Educational Resources Information Center

    Haris, Ikhfan

    2014-01-01

    Information communication and technology (ICT) has been used in various fields. The use of teleconference for teaching and learning activities is currently not a new topic in global world. In Indonesia, through IMHERE Program from Directorate of Higher Education, some universities have been connected with a network of teleconference as a medium of…

  18. Drug-induced weight gain.

    PubMed

    Ness-Abramof, Rosane; Apovian, Caroline M

    2005-01-01

    Drug-induced weight gain is a serious side effect of many commonly used drugs leading to noncompliance with therapy and to exacerbation of comorbid conditions related to obesity. Improved glycemic control achieved by insulin, insulin secretagogues or thiazolidinedione therapy is generally accompanied by weight gain. It is a problematic side effect of therapy due to the known deleterious effect of weight gain on glucose control, increased blood pressure and worsening lipid profile. Weight gain may be lessened or prevented by adherence to diet and exercise or combination therapy with metformin. Weight gain is also common in psychotropic therapy. The atypical antipsychotic drugs (clozapine, olanzepine, risperidone and quetiapine) are known to cause marked weight gain. Antidepressants such as amitriptyline, mirtazapine and some serotonin reuptake inhibitors (SSRIs) also may promote appreciable weight gain that cannot be explained solely by improvement in depressive symptoms. The same phenomenon is observed with mood stabilizers such as lithium, valproic acid and carbamazepine. Antiepileptic drugs (AEDs) that promote weight gain include valproate, carbamazepine and gabapentin. Lamotrigine is an AED that is weight-neutral, while topiramate and zonisamide may induce weight loss. PMID:16341287

  19. Drug-induced weight gain.

    PubMed

    Ness-Abramof, Rosane; Apovian, Caroline M

    2005-08-01

    Drug-induced weight gain is a serious side effect of many commonly used drugs leading to noncompliance with therapy and to exacerbation of comorbid conditions related to obesity. Improved glycemic control achieved by insulin, insulin secretagogues or thiazolidinedione therapy is generally accompanied by weight gain. It is a problematic side effect of therapy due to the known deleterious effect of weight gain on glucose control, increased blood pressure and worsening lipid profile. Weight gain may be lessened or prevented by adherence to diet and exercise or combination therapy with metformin. Weight gain is also common in psychotropic therapy. The atypical antipsychotic drugs (clozapine, olanzepine, risperidone and quetiapine) are known to cause marked weight gain. Antidepressants such as amitriptyline, mirtazapine and some serotonin reuptake inhibitors (SSRIs) also may promote appreciable weight gain that cannot be explained solely by improvement in depressive symptoms. The same phenomenon is observed with mood stabilizers such as lithium, valproic acid and carbamazepine. Antiepileptic drugs (AEDs) that promote weight gain include valproate, carbamazepine and gabapentin. Lamotrigine is an AED that is weight-neutral, while topiramate and zonisamide may induce weight loss. PMID:16234878

  20. Computer algorithm for coding gain

    NASA Technical Reports Server (NTRS)

    Dodd, E. E.

    1974-01-01

    Development of a computer algorithm for coding gain for use in an automated communications link design system. Using an empirical formula which defines coding gain as used in space communications engineering, an algorithm is constructed on the basis of available performance data for nonsystematic convolutional encoding with soft-decision (eight-level) Viterbi decoding.

  1. Image formation using stimulated raman scattering gain

    NASA Astrophysics Data System (ADS)

    Bespalov, V. G.; Makarov, E. A.; Stasel'ko, D. I.

    2016-07-01

    Theoretical analysis of the spatial, noise, and energy characteristics of an amplifier has been performed in the mode of spectral and time selection using subnanosecond stimulated Raman Scattering gain of weak echo signals in crystalline active media that are known for high (up to 10-1 cm/MW) gain coefficients. The possibility to reach high gain values has been demonstrated for weak signals from objects at acceptable angular sizes of the field of vision of an amplifier. To provide a signal-to-noise ratio that exceeds unity over the entire field of vision, the number of photons at the input to an amplifier that is required has to exceed the number of its resolution elements. Accurate determination of the possibilities of recording of weak echo signals and quality of images of targets that are obtained using amplifiers under stimulated Raman Scattering requires additional special experiments.

  2. Reliability of Raw Gain, Residual Gain, and Estimated True Gain Scores: A Simulation Study.

    ERIC Educational Resources Information Center

    Rachor, Robert E.; Cizek, Gregory J.

    The gain, or difference, score is defined as the difference between the posttest score and the pretest score for an individual. Gain scores appear to be a natural measure of growth for education and the social sciences, but they contain two sources of measurement error, error in either the pretest or posttest scores, and cannot be considered…

  3. Simultaneous gain and phase-shift enhancements in periodic gain structures

    SciTech Connect

    Yan, R.H.; Chuang, Z.M.; Corzine, S.W.; Coldren, L.A. )

    1990-05-01

    The recently proposed concept of periodic gain, i.e., dividing the active region into segments placed at optical electric-field standing wave maxima, has been shown to greatly reduce the threshold gain requirement of the active media by up to a factor of 2 in high-finesse vertical cavity surface-emitting lasers. The lasing wavelength is determined by the period of the standing wave; however, previous analyses of these structures have failed to show that a similar enhancement effect occurs for the index shift resulting from the active segments as well. In this communication, we show that effects on both gain and index can be rigorously derived from conventional transmission scattering theory.

  4. Classification of a frameshift/extended and a stop mutation in WT1 as gain-of-function mutations that activate cell cycle genes and promote Wilms tumour cell proliferation

    PubMed Central

    Busch, Maike; Schwindt, Heinrich; Brandt, Artur; Beier, Manfred; Görldt, Nicole; Romaniuk, Paul; Toska, Eneda; Roberts, Stefan; Royer, Hans-Dieter; Royer-Pokora, Brigitte

    2014-01-01

    The WT1 gene encodes a zinc finger transcription factor important for normal kidney development. WT1 is a suppressor for Wilms tumour development and an oncogene for diverse malignant tumours. We recently established cell lines from primary Wilms tumours with different WT1 mutations. To investigate the function of mutant WT1 proteins, we performed WT1 knockdown experiments in cell lines with a frameshift/extension (p.V432fsX87 = Wilms3) and a stop mutation (p.P362X = Wilms2) of WT1, followed by genome-wide gene expression analysis. We also expressed wild-type and mutant WT1 proteins in human mesenchymal stem cells and established gene expression profiles. A detailed analysis of gene expression data enabled us to classify the WT1 mutations as gain-of-function mutations. The mutant WT1Wilms2 and WT1Wilms3 proteins acquired an ability to modulate the expression of a highly significant number of genes from the G2/M phase of the cell cycle, and WT1 knockdown experiments showed that they are required for Wilms tumour cell proliferation. p53 negatively regulates the activity of a large number of these genes that are also part of a core proliferation cluster in diverse human cancers. Our data strongly suggest that mutant WT1 proteins facilitate expression of these cell cycle genes by antagonizing transcriptional repression mediated by p53. We show that mutant WT1 can physically interact with p53. Together the findings show for the first time that mutant WT1 proteins have a gain-of-function and act as oncogenes for Wilms tumour development by regulating Wilms tumour cell proliferation. PMID:24619359

  5. Gaining approval for clinical research.

    PubMed

    Cobb, Vanessa; Srinivasan, Neil; Lambiase, Pier

    2016-07-01

    Set-up and delivery of a clinical research project can be complicated and difficult. This article introduces the regulatory processes involved in gaining approval for clinical research and discusses the obstacles that may be encountered. PMID:27388381

  6. Photochemical Models for Mars' Upper Atmosphere and Ionosphere at Low, Medium, and High Solar Activity: Implications for H2, D, and Evolution of Water

    NASA Astrophysics Data System (ADS)

    Krasnopolsky, V. A.

    2002-05-01

    Self-consistent models for 11 neutral and 18 ion species from 80 to 300 km on Mars have been developed by solving the continuity equations including ambipolar diffusion for ions. The models were calculated for the conditions of the HST, FUSE, and Mariner 6, 7 observations of D, H2, and H, respectively, when solar activity index was 25, 61, and 88 on Mars orbit, respectively. Special care was taken to simulate the processes of H2 and HD dissociation in the reactions with CO2+, O+, CO+, N2+, N+, Ar+, O(1D), and by photoelectrons. Thermal and nonthermal escape velocities were used as the upper boundary conditions for H2, H, HD, D, and He. The calculated ion density profiles at various solar activity and the column reaction rates provide complete quantitative information for behavior of each ion, its formation and loss. The HCO+ ion is abundant in Mars' ionosphere because it is a final product of many reactions of other ions with H2 and does not react with neutral species. The H2 and D mixing ratios of 15 ppm and 11 ppb chosen to fit the FUSE and HST observations of H2 and D, respectively, result in (HD/H2)/(HDO/H2O) = 0.41. This value agrees with the depletion of D in H2 because of the smaller HDO photolysis cross section, the preferential condensation of HDO above the hygropause, and the fractionation in chemical reactions that result in the formation of H2. Therefore the controversial problem of deuterium fractionation is solved throughout the atmosphere. Isotope fractionation factor for hydrogen escape is equal to 0.055, 0.082, and 0.167 for low, medium, and high solar activity, respectively, and the solar cycle mean value is 0.105. The polar caps shrink or dissappear at high obliquity, and water in the polar caps is in isotopic equilibrium with the atmospheric water. Using the water amount of 14 m in the polar caps, the fractionation factor, the present D/H ratio and that at the end of hydrodynamic escape (5.5 and 1.9 times the terrestrial ratio, respectively

  7. Modal Analysis and Gain Estimation

    NASA Technical Reports Server (NTRS)

    Jones, R. L.

    1986-01-01

    Interactive program yields eigenvectors, eigenvalues, and gains for feedback-control systems. Interactive Modal Analysis and Gain Estimation System (IMAGES) provides eigensystem synthesis capability to control-system engineer. IMAGES modular and flexible. Capable of both modal and spectral synthesis of multi-input control systems. IMAGES user-oriented, interactive program that frees engineer to concentrate on eigensystem synthesis. Engineer provided with scratch-pad capability that speeds control-system design.

  8. Developmental gains in visuospatial memory predict gains in mathematics achievement.

    PubMed

    Li, Yaoran; Geary, David C

    2013-01-01

    Visuospatial competencies are related to performance in mathematical domains in adulthood, but are not consistently related to mathematics achievement in children. We confirmed the latter for first graders and demonstrated that children who show above average first-to-fifth grade gains in visuospatial memory have an advantage over other children in mathematics. The study involved the assessment of the mathematics and reading achievement of 177 children in kindergarten to fifth grade, inclusive, and their working memory capacity and processing speed in first and fifth grade. Intelligence was assessed in first grade and their second to fourth grade teachers reported on their in-class attentive behavior. Developmental gains in visuospatial memory span (d = 2.4) were larger than gains in the capacity of the central executive (d = 1.6) that in turn were larger than gains in phonological memory span (d = 1.1). First to fifth grade gains in visuospatial memory and in speed of numeral processing predicted end of fifth grade mathematics achievement, as did first grade central executive scores, intelligence, and in-class attentive behavior. The results suggest there are important individual differences in the rate of growth of visuospatial memory during childhood and that these differences become increasingly important for mathematics learning. PMID:23936154

  9. High gain/broadband oxide glasses for next generation Raman amplifiers

    NASA Astrophysics Data System (ADS)

    Rivero, Clara A.

    Interest in Raman amplification has undergone a revival due to the rapidly increasing bandwidth requirements for communications transmission, both for long haul and local area networks, and recent developments in the telecom fiber industry and diode laser technology. In contrast to rare earth doped fiber amplifiers, for which the range of wavelengths is fixed and limited, Raman gain bandwidths are larger and the operating wavelength is fixed only by the pump wavelength and the bandwidth of the Raman active medium. In this context, glasses are the material of choice for this application due to their relatively broad spectral response, and ability of making them into optical fiber. This dissertation summarizes findings on different oxide-based glasses that have been synthesized and characterized for their potential application as Raman gain media. Two main glass families were investigated: phosphate-based glass matrices for broadband Raman gain application and TeO2-based glasses for high Raman gain amplification. A phosphate network was preferred for the broadband application since the phosphate Raman active modes can provide amplification above 1000 cm-1, whilst TeO2-based glasses were selected for the high gain application due to their enhanced nonlinearities and polarizabilities among the other oxide-based network formers. The results summarized in this dissertation show that phosphate-based glasses can provide Raman amplification bandwidths of up to 40 THz, an improvement of almost 5 times the bandwidth of SiO2. On the other hand, tellurite-based glasses appear to be promising candidates for high gain discrete Raman applications, providing peak Raman gain coefficients of up to 50 times higher than SiO 2, at 1064 nm. Although, visible spontaneous Raman scattering cross-section measurement is the most frequently used tool for estimating the strength and spectral distribution of Raman gain in materials, especially glasses, there are some issues that one needs to be

  10. Gain properties of dye-doped polymer thin films

    NASA Astrophysics Data System (ADS)

    Gozhyk, I.; Boudreau, M.; Haghighi, H. Rabbani; Djellali, N.; Forget, S.; Chénais, S.; Ulysse, C.; Brosseau, A.; Pansu, R.; Audibert, J.-F.; Gauvin, S.; Zyss, J.; Lebental, M.

    2015-12-01

    Hybrid pumping appears as a promising compromise in order to reach the much coveted goal of an electrically pumped organic laser. In such configuration the organic material is optically pumped by an electrically pumped inorganic device on a chip. This engineering solution requires therefore an optimization of the organic gain medium under optical pumping. Here, we report a detailed study of the gain features of dye-doped polymer thin films. In particular we introduce the gain efficiency K , in order to facilitate comparison between different materials and experimental conditions. The gain efficiency was measured with a variety of experimental methods (pump-probe amplification, variable stripe length method, laser thresholds) in order to study several factors which modify the actual gain of a layer, namely the confinement factor, the pump polarization, the molecular anisotropy, and the re-absorption. For instance, for a 600-nm-thick 5-wt % DCM doped poly(methyl methacrylate) (PMMA) layer, the different experimental approaches give a consistent value of K ≃ 80 -cm MW-1 . On the contrary, the usual model predicting the gain from the characteristics of the material leads to an overestimation by two orders of magnitude, which raises a serious problem in the design of actual devices. In this context, we demonstrate the feasibility to infer the gain efficiency from the laser threshold of well-calibrated devices. Temporal measurements at the picosecond scale were carried out to support the analysis.

  11. Reflection of processes of non-equilibrium two-phase filtration in oil-saturated hierarchical medium in data of active wave geophysical monitoring

    NASA Astrophysics Data System (ADS)

    Hachay, Olga; Khachay, Andrey; Khachay, Oleg

    2016-04-01

    The processes of oil extraction from deposit are linked with the movement of multi-phase multi-component media, which are characterized by non-equilibrium and non-linear rheological features. The real behavior of layered systems is defined by the complexity of the rheology of moving fluids and the morphology structure of the porous medium, and also by the great variety of interactions between the fluid and the porous medium [Hasanov and Bulgakova, 2003]. It is necessary to take into account these features in order to informatively describe the filtration processes due to the non-linearity, non-equilibrium and heterogeneity that are features of real systems. In this way, new synergetic events can be revealed (namely, a loss of stability when oscillations occur, and the formation of ordered structures). This allows us to suggest new methods for the control and management of complicated natural systems that are constructed on account of these phenomena. Thus the layered system, from which it is necessary to extract the oil, is a complicated dynamical hierarchical system. A comparison is provided of non-equilibrium effects of the influence of independent hydrodynamic and electromagnetic induction on an oil layer and the medium which it surrounds. It is known that by drainage and steeping the hysteresis effect on curves of the relative phase permeability in dependence on the porous medium's water saturation in some cycles of influence (drainage-steep-drainage) is observed. Using the earlier developed 3D method of induction electromagnetic frequency geometric monitoring, we showed the possibility of defining the physical and structural features of a hierarchical oil layer structure and estimating the water saturation from crack inclusions. This effect allows managing the process of drainage and steeping the oil out of the layer by water displacement. An algorithm was constructed for 2D modeling of sound diffraction on a porous fluid-saturated intrusion of a hierarchical

  12. Simple ABCD matrix treatment for transversely varying saturable gain.

    PubMed

    Grace, E J; New, G H; French, P M

    2001-11-15

    We have developed an ABCD matrix that, for the first time to our knowledge, accurately describes the transformation of a Gaussian beam by a medium with transversely varying saturable gain. In contrast with the conventional ABCD matrix, the newly developed matrix is shown to be in excellent agreement with a full beam propagation code over a wide parameter range. Accurate treatment of transversely varying saturable gain in laser resonators is important for the optimization of end-pumped lasers, particularly for efficient diode-pumped solid-state and Kerr-lens mode-locked systems. PMID:18059695

  13. Ca2+ enrichment in culture medium potentiates effect of oligonucleotides.

    PubMed

    Hori, Shin-Ichiro; Yamamoto, Tsuyoshi; Waki, Reiko; Wada, Shunsuke; Wada, Fumito; Noda, Mio; Obika, Satoshi

    2015-10-30

    Antisense and RNAi-related oligonucleotides have gained attention as laboratory tools and therapeutic agents based on their ability to manipulate biological events in vitro and in vivo. We show that Ca(2+) enrichment of medium (CEM) potentiates the in vitro activity of multiple types of oligonucleotides, independent of their net charge and modifications, in various cells. In addition, CEM reflects in vivo silencing activity more consistently than conventional transfection methods. Microscopic analysis reveals that CEM provides a subcellular localization pattern of oligonucleotides resembling that obtained by unassisted transfection, but with quantitative improvement. Highly monodispersed nanoparticles ~100 nm in size are found in Ca(2+)-enriched serum-containing medium regardless of the presence or absence of oligonucleotides. Transmission electron microscopy analysis reveals that the 100-nm particles are in fact an ensemble of much smaller nanoparticles (ϕ ∼ 15 nm). The presence of these nanoparticles is critical for the efficient uptake of various oligonucleotides. In contrast, CEM is ineffective for plasmids, which are readily transfected via the conventional calcium phosphate method. Collectively, CEM enables a more accurate prediction of the systemic activity of therapeutic oligonucleotides, while enhancing the broad usability of oligonucleotides in the laboratory. PMID:26101258

  14. Ca2+ enrichment in culture medium potentiates effect of oligonucleotides

    PubMed Central

    Hori, Shin-ichiro; Yamamoto, Tsuyoshi; Waki, Reiko; Wada, Shunsuke; Wada, Fumito; Noda, Mio; Obika, Satoshi

    2015-01-01

    Antisense and RNAi-related oligonucleotides have gained attention as laboratory tools and therapeutic agents based on their ability to manipulate biological events in vitro and in vivo. We show that Ca2+ enrichment of medium (CEM) potentiates the in vitro activity of multiple types of oligonucleotides, independent of their net charge and modifications, in various cells. In addition, CEM reflects in vivo silencing activity more consistently than conventional transfection methods. Microscopic analysis reveals that CEM provides a subcellular localization pattern of oligonucleotides resembling that obtained by unassisted transfection, but with quantitative improvement. Highly monodispersed nanoparticles ∼100 nm in size are found in Ca2+-enriched serum-containing medium regardless of the presence or absence of oligonucleotides. Transmission electron microscopy analysis reveals that the 100-nm particles are in fact an ensemble of much smaller nanoparticles (ϕ ∼ 15 nm). The presence of these nanoparticles is critical for the efficient uptake of various oligonucleotides. In contrast, CEM is ineffective for plasmids, which are readily transfected via the conventional calcium phosphate method. Collectively, CEM enables a more accurate prediction of the systemic activity of therapeutic oligonucleotides, while enhancing the broad usability of oligonucleotides in the laboratory. PMID:26101258

  15. CBI: Systems or Medium?

    ERIC Educational Resources Information Center

    Higginbotham-Wheat, Nancy L.

    This paper addresses one area of conflict in decisionmaking in computer-based instruction (CBI) research: the relationship between the researcher's definition of CBI either as a medium or as an integrated system and the design of meaningful research questions. (A medium is defined here as a device for the delivery of instruction, while an…

  16. Synthetic laser medium

    DOEpatents

    Stokowski, Stanley E.

    1989-01-01

    A laser medium is particularly useful in high average power solid state lasers. The laser medium includes a chormium dopant and preferably neodymium ions as codopant, and is primarily a gadolinium scandium gallium garnet, or an analog thereof. Divalent cations inhibit spiral morphology as large boules from which the laser medium is derived are grown, and a source of ions convertible between a trivalent state and a tetravalent state at a low ionization energy are in the laser medium to reduce an absorption coefficient at about one micron wavelength otherwise caused by the divalent cations. These divalent cations and convertible ions are dispersed in the laser medium. Preferred convertible ions are provided from titanium or cerium sources.

  17. Synthetic laser medium

    DOEpatents

    Stokowski, S.E.

    1987-10-20

    A laser medium is particularly useful in high average power solid state lasers. The laser medium includes a chromium dopant and preferably neodymium ions as codopant, and is primarily a gadolinium scandium gallium garnet, or an analog thereof. Divalent cations inhibit spiral morphology as large boules from which the laser medium is derived are grown, and a source of ions convertible between a trivalent state and a tetravalent state at a low ionization energy are in the laser medium to reduce an absorption coefficient at about one micron wavelength otherwise caused by the divalent cations. These divalent cations and convertible ions are dispersed in the laser medium. Preferred convertible ions are provided from titanium or cerium sources.

  18. Antidiabetic activity of medium-polar extract from the leaves of Stevia rebaudiana Bert. (Bertoni) on alloxan-induced diabetic rats

    PubMed Central

    Misra, Himanshu; Soni, Manish; Silawat, Narendra; Mehta, Darshana; Mehta, B. K.; Jain, D. C.

    2011-01-01

    Objective: To investigate the medicative effects of medium-polar (benzene:acetone, 1:1, v/v) extract of leaves from Stevia rebaudiana (family Asteraceae) on alloxan-induced diabetic rats. Materials and Methods: Diabetes was induced in adult albino Wistar rats by intraperitoneal (i.p.) injection of alloxan (180 mg/kg). Medium-polar extract was administered orally at daily dose of 200 and 400 mg/kg body wt. basis for 10 days. The control group received normal saline (0.9%) for the same duration. Glibenclamide was used as positive control reference drug against Stevia extract. Results: Medium-polar leaf extract of S. rebaudiana (200 and 400 mg/kg) produced a delayed but significant (P < 0.01) decrease in the blood glucose level, without producing condition of hypoglycemia after treatment, together with lesser loss in the body weight as compared with standard positive control drug glibenclamide. Conclusions: Treatment of diabetes with sulfonylurea drugs (glibenclamide) causes hypoglycemia followed by greater reduction in body weight, which are the most worrisome effects of these drugs. Stevia extract was found to antagonize the necrotic action of alloxan and thus had a re-vitalizing effect on β-cells of pancreas. PMID:21687353

  19. Commutated automatic gain control system

    NASA Technical Reports Server (NTRS)

    Yost, S. R.

    1981-01-01

    A commutated automatic gain control system (AGC) was designed and constructed for the prototype Loran C receiver. The AGC is designed to improve the signal-to-signal ratio of the received Loran signals. The AGC design does not require any analog to digital conversion and it utilizes commonly available components. The AGC consists of: (1) a circuit which samples the peak of the envelope of the Loran signal to obtain an AGC voltage for each of three Loran stations, (2) a dc gain circuit to control the overall gain of the AGC system, and (3) an AGC amplification of the input RF signal. The performance of the AGC system was observed in bench and flight tests; it has improved the overall accuracy of the receiver. Improvements in the accuracy of the time difference calculations to within approx. + or - 1.5 microseconds of the observed time differnces for a given position are reported.

  20. High current gain transistor laser.

    PubMed

    Liang, Song; Qiao, Lijun; Zhu, Hongliang; Wang, Wei

    2016-01-01

    A transistor laser (TL), having the structure of a transistor with multi-quantum wells near its base region, bridges the functionality gap between lasers and transistors. However, light emission is produced at the expense of current gain for all the TLs reported up to now, leading to a very low current gain. We propose a novel design of TLs, which have an n-doped InP layer inserted in the emitter ridge. Numerical studies show that a current flow aperture for only holes can be formed in the center of the emitter ridge. As a result, the common emitter current gain can be as large as 143.3, which is over 15 times larger than that of a TL without the aperture. Besides, the effects of nonradiative recombination defects can be reduced greatly because the flow of holes is confined in the center region of the emitter ridge. PMID:27282466

  1. High current gain transistor laser

    NASA Astrophysics Data System (ADS)

    Liang, Song; Qiao, Lijun; Zhu, Hongliang; Wang, Wei

    2016-06-01

    A transistor laser (TL), having the structure of a transistor with multi-quantum wells near its base region, bridges the functionality gap between lasers and transistors. However, light emission is produced at the expense of current gain for all the TLs reported up to now, leading to a very low current gain. We propose a novel design of TLs, which have an n-doped InP layer inserted in the emitter ridge. Numerical studies show that a current flow aperture for only holes can be formed in the center of the emitter ridge. As a result, the common emitter current gain can be as large as 143.3, which is over 15 times larger than that of a TL without the aperture. Besides, the effects of nonradiative recombination defects can be reduced greatly because the flow of holes is confined in the center region of the emitter ridge.

  2. High current gain transistor laser

    PubMed Central

    Liang, Song; Qiao, Lijun; Zhu, Hongliang; Wang, Wei

    2016-01-01

    A transistor laser (TL), having the structure of a transistor with multi-quantum wells near its base region, bridges the functionality gap between lasers and transistors. However, light emission is produced at the expense of current gain for all the TLs reported up to now, leading to a very low current gain. We propose a novel design of TLs, which have an n-doped InP layer inserted in the emitter ridge. Numerical studies show that a current flow aperture for only holes can be formed in the center of the emitter ridge. As a result, the common emitter current gain can be as large as 143.3, which is over 15 times larger than that of a TL without the aperture. Besides, the effects of nonradiative recombination defects can be reduced greatly because the flow of holes is confined in the center region of the emitter ridge. PMID:27282466

  3. Strongly localized moving discrete dissipative breather-solitons in Kerr nonlinear media supported by intrinsic gain

    NASA Astrophysics Data System (ADS)

    Johansson, Magnus; Prilepsky, Jaroslaw E.; Derevyanko, Stanislav A.

    2014-04-01

    We investigate the mobility of nonlinear localized modes in a generalized discrete Ginzburg-Landau-type model, describing a one-dimensional waveguide array in an active Kerr medium with intrinsic, saturable gain and damping. It is shown that exponentially localized, traveling discrete dissipative breather-solitons may exist as stable attractors supported only by intrinsic properties of the medium, i.e., in the absence of any external field or symmetry-breaking perturbations. Through an interplay by the gain and damping effects, the moving soliton may overcome the Peierls-Nabarro barrier, present in the corresponding conservative system, by self-induced time-periodic oscillations of its power (norm) and energy (Hamiltonian), yielding exponential decays to zero with different rates in the forward and backward directions. In certain parameter windows, bistability appears between fast modes with small oscillations and slower, large-oscillation modes. The velocities and the oscillation periods are typically related by lattice commensurability and exhibit period-doubling bifurcations to chaotically "walking" modes under parameter variations. If the model is augmented by intersite Kerr nonlinearity, thereby reducing the Peierls-Nabarro barrier of the conservative system, the existence regime for moving solitons increases considerably, and a richer scenario appears including Hopf bifurcations to incommensurately moving solutions and phase-locking intervals. Stable moving breathers also survive in the presence of weak disorder.

  4. Welfare Gains from Financial Liberalization

    PubMed Central

    Townsend, Robert M.; Ueda, Kenichi

    2010-01-01

    Financial liberalization has been a controversial issue, as empirical evidence for growth enhancing effects is mixed. Here, we find sizable welfare gains from liberalization (cost to repression), though the gain in economic growth is ambiguous. We take the view that financial liberalization is a government policy that alters the path of financial deepening, while financial deepening is endogenously chosen by agents given a policy and occurs in transition towards a distant steady state. This history-dependent view necessitates the use of simulation analysis based on a growth model. Our application is a specific episode: Thailand from 1976 to 1996. PMID:20806055

  5. Releasing resources for reinvestment in health gain.

    PubMed

    Riley, C D; Warner, M M; Simpson, D; Felvus, J

    1992-01-01

    The National Health Services in Wales has adopted a strategic approach based on health gain. Five approaches to meeting this problem are considered (i) eliminating basic inefficiencies; (ii) eliminating unnecessary clinical activity; (iii) doing what is done now but differently; (iv) investing now to save later and (v) withdrawing from a particular area of activity, because it is less important than other competing claims. Each of these is briefly considered with particular reference to the Welsh situation. Three particular lines of advance are identified to achieve the above: creating new sources of information; working more effectively across organisational boundaries; and making the cultural changes to make it all possible. PMID:10166349

  6. The effects of neural gain on attention and learning.

    PubMed

    Eldar, Eran; Cohen, Jonathan D; Niv, Yael

    2013-08-01

    Attention is commonly thought to be manifest through local variations in neural gain. However, what would be the effects of brain-wide changes in gain? We hypothesized that global fluctuations in gain modulate the breadth of attention and the degree to which processing is focused on aspects of the environment to which one is predisposed to attend. We found that measures of pupil diameter, which are thought to track levels of locus coeruleus norepinephrine activity and neural gain, were correlated with the degree to which learning was focused on stimulus dimensions that individual human participants were more predisposed to process. In support of our interpretation of this effect in terms of global changes in gain, we found that the measured pupillary and behavioral variables were strongly correlated with global changes in the strength and clustering of functional connectivity, as brain-wide fluctuations of gain would predict. PMID:23770566

  7. Simulation of an X-ray laser in the transient gain-saturation regime

    SciTech Connect

    Starikov, F A; Volkov, V A; Gasparyan, P D; Roslov, V I

    2009-09-30

    By using the TRANS code, we performed three-dimensional calculations of amplified spontaneous emission (ASE) in X-ray lasers on the 3p-3s transition in Ne-like Ge ({lambda} = 19.6 nm) and Ti ({lambda} = 2.6 nm) operating in the transient regime upon irradiation of a flat target by a high-power picosecond laser pulse focused into a line with one or two nanosecond prepulses. The hydrodynamics and population kinetics of the active medium of X-ray lasers were calculated by using the SS-9M code. The pulse duration, the gain, the spatial structure of the laser beam and the type of influence of a 'travelling' pump wave on the ASE brightness obtained in calculations are in agreement with the experimental data. The use of the 'travelling pump wave' leads not only to the increase in the ASE brightness but also considerably reduces its angular divergence. (active media)

  8. Yield gains in leafy vegetables

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yield of all crops have increased during the past century through improved cultural practices and plant breeding. We reviewed gains in yield of lettuce and spinach in the U.S., principally California and Arizona. We proposed several genetic models for yield of lettuce based on the market type: whole...

  9. Mutual Gains Means Everyone Wins.

    ERIC Educational Resources Information Center

    Flaherty, Bernard L.

    1997-01-01

    Mutual gains negotiation is an innovative system that emphasizes interests instead of positions and problem solving instead of preconceived solutions. The process can reverse social disintegration, reverse worker alienation, and address a shifting educational environment. It can resolve difficult labor-management problems such as contracting out,…

  10. The Gains from Vertical Scaling

    ERIC Educational Resources Information Center

    Briggs, Derek C.; Domingue, Ben

    2013-01-01

    It is often assumed that a vertical scale is necessary when value-added models depend upon the gain scores of students across two or more points in time. This article examines the conditions under which the scale transformations associated with the vertical scaling process would be expected to have a significant impact on normative interpretations…

  11. Gaining Perspective on Parenting Groups.

    ERIC Educational Resources Information Center

    Fenichel, Emily, Ed.

    1996-01-01

    This theme issue offers a collection of articles focusing on support groups for parents of infants and toddlers, including the following: (1) "Gaining Perspective on Parenting Groups" (Nick Carter and Cathie Harvey) which reviews the purposes, history, and essential ingredients of such groups; (2) "The MELD Experience with Parent Groups" (Joyce…

  12. Inhibition of Hyperpolarization-Activated Cation Current in Medium-Sized DRG Neurons Contributed to the Antiallodynic Effect of Methylcobalamin in the Rat of a Chronic Compression of the DRG

    PubMed Central

    Zhang, Ming; Han, Wenjuan; Zheng, Jianyong; Meng, Fancheng; Jiao, Xiying; Hu, Sanjue; Xu, Hui

    2015-01-01

    Recently several lines of evidence demonstrated that methylcobalamin (MeCbl) might have potential analgesic effect in experimental and clinical studies. However, it was reported that MeCbl had no effect on treating lumbar spinal stenosis induced pain. Thus, the effects of short-term and long-term administration of MeCbl were examined in the chronic compression of dorsal root ganglion (CCD) model. We found that mechanical allodynia was significantly inhibited by a continuous application of high dose and a single treatment of a super high dose of MeCbl. Little is known about mechanisms underlying the analgesia of MeCbl. We examined the effect of MeCbl on the spontaneous activity (SA), the excitability, and hyperpolarization-activated nonselective cation ion current in compressed medium-sized dorsal root ganglion (DRG) neurons using extracellular single fiber recording in vivo and whole-cell patch clamp in vitro. We found that MeCbl significantly inhibited the SA of A-type sensory neurons in a dose-dependent manner and inhibited the excitability of medium-sized DRG neurons. In addition, MeCbl also decreased Ih current density in injured medium-sized DRG neurons. Our results proved that MeCbl might exert an analgesic effect through the inhibition Ih current and then might inhibit the hyperexcitability of primary sensory neurons under neuropathic pain state. PMID:26101670

  13. Sympathetic baroreflex gain in normotensive pregnant women

    PubMed Central

    Usselman, Charlotte W.; Skow, Rachel J.; Matenchuk, Brittany A.; Chari, Radha S.; Julian, Colleen G.; Stickland, Michael K.; Davenport, Margie H.

    2015-01-01

    Muscle sympathetic nerve activity is increased during normotensive pregnancy while mean arterial pressure is maintained or reduced, suggesting baroreflex resetting. We hypothesized spontaneous sympathetic baroreflex gain would be reduced in normotensive pregnant women relative to nonpregnant matched controls. Integrated muscle sympathetic burst incidence and total sympathetic activity (microneurography), blood pressure (Finometer), and R-R interval (ECG) were assessed at rest in 11 pregnant women (33 ± 1 wk gestation, 31 ± 1 yr, prepregnancy BMI: 23.5 ± 0.9 kg/m2) and 11 nonpregnant controls (29 ± 1 yr; BMI: 25.2 ± 1.7 kg/m2). Pregnant women had elevated baseline sympathetic burst incidence (43 ± 2 vs. 33 ± 2 bursts/100 heart beats, P = 0.01) and total sympathetic activity (1,811 ± 148 vs. 1,140 ± 55 au, P < 0.01) relative to controls. Both mean (88 ± 3 vs. 91 ± 2 mmHg, P = 0.4) and diastolic (DBP) (72 ± 3 vs. 73 ± 2 mmHg, P = 0.7) pressures were similar between pregnant and nonpregnant women, respectively, indicating an upward resetting of the baroreflex set point with pregnancy. Baroreflex gain, calculated as the linear relationship between sympathetic burst incidence and DBP, was reduced in pregnant women relative to controls (−3.7 ± 0.5 vs. −5.4 ± 0.5 bursts·100 heart beats−1·mmHg−1, P = 0.03), as was baroreflex gain calculated with total sympathetic activity (−294 ± 24 vs. −210 ± 24 au·100 heart beats−1·mmHg−1; P = 0.03). Cardiovagal baroreflex gain (sequence method) was not different between nonpregnant controls and pregnant women (49 ± 8 vs. 36 ± 8 ms/mmHg; P = 0.2). However, sympathetic (burst incidence) and cardiovagal gains were negatively correlated in pregnant women (R = −0.7; P = 0.02). Together, these data indicate that the influence of the sympathetic nervous system over arterial blood pressure is reduced in normotensive pregnancy, in terms of both long-term and beat-to-beat regulation of arterial pressure

  14. Chemically defined medium and Caenorhabditis elegans

    NASA Technical Reports Server (NTRS)

    Szewczyk, Nathaniel J.; Kozak, Elena; Conley, Catharine A.

    2003-01-01

    BACKGROUND: C. elegans has been established as a powerful genetic system. Use of a chemically defined medium (C. elegans Maintenance Medium (CeMM)) now allows standardization and systematic manipulation of the nutrients that animals receive. Liquid cultivation allows automated culturing and experimentation and should be of use in large-scale growth and screening of animals. RESULTS: We find that CeMM is versatile and culturing is simple. CeMM can be used in a solid or liquid state, it can be stored unused for at least a year, unattended actively growing cultures may be maintained longer than with standard techniques, and standard C. elegans protocols work well with animals grown in defined medium. We also find that there are caveats to using defined medium. Animals in defined medium grow more slowly than on standard medium, appear to display adaptation to the defined medium, and display altered growth rates as they change the composition of the defined medium. CONCLUSIONS: As was suggested with the introduction of C. elegans as a potential genetic system, use of defined medium with C. elegans should prove a powerful tool.

  15. Optofluidic lasers with a single molecular layer of gain

    PubMed Central

    Chen, Qiushu; Ritt, Michael; Sivaramakrishnan, Sivaraj; Sun, Yuze; Fan, Xudong

    2014-01-01

    We achieve optofluidic lasers with a single molecular layer of gain, in which green fluorescent protein, dye-labeled bovine serum albumin, and dye-labeled DNA are respectively used as the gain medium and attached to the surface of a ring resonator via surface immobilization biochemical methods. It is estimated that the surface density of the gain molecules is on the order of 1012/cm2, sufficient for lasing under pulsed optical excitation. It is further shown that the optofluidic laser can be tuned by energy transfer mechanisms through biomolecular interactions. This work not only opens a door to novel photonic devices that can be controlled at the level of a single molecular layer, but also provides a promising sensing platform to analyze biochemical processes at the solid-liquid interface. PMID:25312306

  16. Intensity fluctuations in bimodal micropillar lasers enhanced by quantum-dot gain competition

    NASA Astrophysics Data System (ADS)

    Leymann, H. A. M.; Hopfmann, C.; Albert, F.; Foerster, A.; Khanbekyan, M.; Schneider, C.; Höfling, S.; Forchel, A.; Kamp, M.; Wiersig, J.; Reitzenstein, S.

    2013-05-01

    We investigate correlations between orthogonally polarized cavity modes of a bimodal micropillar laser with a single layer of self-assembled quantum dots in the active region. While one emission mode of the microlaser demonstrates a characteristic S-shaped input-output curve, the output intensity of the second mode saturates and even decreases with increasing injection current above threshold. Measuring the photon autocorrelation function g(2)(τ) of the light emission confirms the onset of lasing in the first mode with g(2)(0) approaching unity above threshold. In contrast, strong photon bunching associated with superthermal values of g(2)(0) is detected for the other mode for currents above threshold. This behavior is attributed to gain competition of the two modes induced by the common gain material, which is confirmed by photon cross-correlation measurements revealing a clear anticorrelation between emission events of the two modes. The experimental studies are in qualitative agreement with theoretical studies based on a microscopic semiconductor theory, which we extend to the case of two modes interacting with the common gain medium. Moreover, we treat the problem by a phenomenological birth-death model extended to two interacting modes, which reveals that the photon probability distribution of each mode has a double-peak structure, indicating switching behavior of the modes for pump rates around threshold.

  17. Nonlinear optical properties of the active medium in intracavity phase conjugation of the radiation of a pulsed electron-beam-controlled discharge CO{sub 2} laser. I. Experiments

    SciTech Connect

    Galushkin, M G; Mitin, Konstantin V; Ionin, Andrei A; Kotkov, A A; Seleznev, L V

    1998-08-31

    An experimental investigation was made of phase conjugation in the course of intracavity degenerate four-wave mixing of radiation in the active medium of a pulsed electron-beam-controlled discharge CO{sub 2} laser generating long pulses. An analysis was carried out of the dependences of the energy and temporal characteristics of a phase-conjugated signal on the specific input energy deposited in the electron-beam-controlled discharge, on the Q-factor of the laser cavity, on the composition and pressure of the laser-active mixture, on the angle of interaction and optical delay between the probe and reference waves, on the ratio of the intensities of these two waves, and on the polarisation and spectral composition of laser radiation. The energy reflection coefficient of the phase-conjugated signal increased with increase in the input energy and with reduction in the probe wave intensity. An increase in the proportion of nitrogen and a reduction in the proportion of helium in the laser-active mixture increased the reflection coefficient and gave rise to a specific profile of the phase-conjugated signal with two maxima, attributed to amplitude and phase nonlinearities of the active medium. An increase in the specific input energy and of the cavity Q-factor reduced the response time of the phase-conjugate signal. (nonlinear optical phenomena and devices)

  18. Photomultiplier tube gain regulating system

    DOEpatents

    Johnson, Wayne F.

    1976-01-01

    This invention relates to an improved system for regulating the gain of a photomultiplier tube, and was designed for use with the photomultiplier tubes of a GeMSAEC fast analyzers. It has the following advantages over the prior system: noise is virtually eliminated; sample analysis can begin after 3 to 4 revolutions of the rotor; fluorescent and light scattering solutions can be used as a reference; and the reference solution can be in any cuvette on the rotor.

  19. Gain functionalization of silica microresonators.

    PubMed

    Yang, Lan; Vahala, K J

    2003-04-15

    Erbium-doped solgel films are applied to the surface of silica microspheres to create low-threshold microactivity lasers. This gain functionalization can be applied by use of a number of different dopants, thereby extending the wavelength range of this class of device. Also, by varying the doping concentration and thickness of the applied solgel layer, one can vary the laser dynamics so that both continuous-wave and pulsating modes of operation are possible. PMID:12703910

  20. Spatially resolved sub-Doppler overtone gain measurements on a small-scale supersonic HF laser

    NASA Astrophysics Data System (ADS)

    Wisniewski, Charles F.; Hewett, Kevin B.; Manke, Gerald C., II; Truman, C. Randall; Hager, Gordon D.

    2004-05-01

    The small signal gain of a small-scale HF overtone laser was measured using a sub-Doppler tunable diode laser system. Measurements of reactant concentration, flow velocity and gain length were also made. The spatially resolved, two-dimensional small signal gain and temperature maps that were generated show a highly inhomogeneous gain medium indicating the dominant role played by mixing of the H2 and F streams in HF laser performance. The measured gain and temperature data were analyzed with the aid of a two-dimensional computational fluid dynamics model. The results show that reactant mixing mechanisms have a large effect on the gain averaged over a vertical profile while kinetic rate mechanisms, including reaction rate constants and reactant concentration, have a greater effect on the maximum system gain.

  1. The violent interstellar medium

    NASA Technical Reports Server (NTRS)

    Mccray, R.; Snow, T. P., Jr.

    1979-01-01

    Observational evidence for high-velocity and high-temperature interstellar gas is reviewed. The physical processes that characterize this gas are described, including the ionization and emissivity of coronal gas, the behavior and appearance of high-velocity shocks, and interfaces between coronal gas and cooler interstellar gas. Hydrodynamical models for the action of supernova explosions and stellar winds on the interstellar medium are examined, and recent attempts to synthesize all the processes considered into a global model for the interstellar medium are discussed.

  2. Commutated automatic gain control system

    NASA Technical Reports Server (NTRS)

    Yost, S. R.

    1982-01-01

    The commutated automatic gain control (AGC) system was designed and built for the prototype Loran-C receiver is discussed. The current version of the prototype receiver, the Mini L-80, was tested initially in 1980. The receiver uses a super jolt microcomputer to control a memory aided phase loop (MAPLL). The microcomputer also controls the input/output, latitude/longitude conversion, and the recently added AGC system. The AGC control adjusts the level of each station signal, such that the early portion of each envelope rise is about at the same amplitude in the receiver envelope detector.

  3. Commutated automatic gain control system

    NASA Technical Reports Server (NTRS)

    Yost, S. R.

    1982-01-01

    A commutated automatic gain control (AGC) system was designed and built for a prototype Loran C receiver. The receiver uses a microcomputer to control a memory aided phase-locked loop (MAPLL). The microcomputer also controls the input/output, latitude/longitude conversion, and the recently added AGC system. The circuit designed for the AGC is described, and bench and flight test results are presented. The AGC circuit described actually samples starting at a point 40 microseconds after a zero crossing determined by the software lock pulse ultimately generated by a 30 microsecond delay and add network in the receiver front end envelope detector.

  4. [Fast food promotes weight gain].

    PubMed

    Stender, Steen; Dyerberg, Jørn; Astrup, Arne V

    2007-05-01

    The total amounts of fat in a fast food menu consisting of French fries and fried Chicken Nuggets from McDonald's and KFC, respectively, bought in 35 different countries vary from 41 to 71 gram. In most countries the menu contained unacceptably high amounts of industrially-produced trans fat which contributes to an increased risk of ischaemic heart disease, weight gain, abdominal fat accumulation and type 2 diabetes. The quality of the ingredients in fast food ought to be better and the size of the portions smaller and less energy-dense so that frequent fast food meals do not increase the risk of obesity and diseases among customers. PMID:17537359

  5. A gain-coefficient switched Alexandrite laser

    NASA Astrophysics Data System (ADS)

    Lee, Chris J.; van der Slot, Peter J. M.; Boller, Klaus-J.

    2013-01-01

    We report on a gain-coefficient switched Alexandrite laser. An electro-optic modulator is used to switch between high and low gain states by making use of the polarization dependent gain of Alexandrite. In gain-coefficient switched mode, the laser produces 85 ns pulses with a pulse energy of 240 mJ at a repetition rate of 5 Hz.

  6. Development and Demonstration of a Low Cost Hybrid Drive Train for Medium and Heavy Duty Vehicles

    SciTech Connect

    Strangas, Elias; Schock, Harold; Zhu, Guoming; Moran, Kevin; Ruckle, Trevor; Foster, Shanelle; Cintron-Rivera, Jorge; Tariq, Abdul; Nino-Baron, Carlos

    2011-04-30

    The DOE sponsored effort is part of a larger effort to quantify the efficiency of hybrid powertrain systems through testing and modeling. The focus of the DOE sponsored activity was the design, development and testing of hardware to evaluate the efficiency of the electrical motors relevant to medium duty vehicles. Medium duty hybrid powertrain motors and generators were designed, fabricated, setup and tested. The motors were a permanent magnet configuration, constructed at Electric Apparatus Corporation in Howell, Michigan. The purpose of this was to identify the potential gains in terms of fuel cost savings that could be realized by implementation of such a configuration. As the electric motors constructed were prototype designs, the scope of the project did not include calculation of the costs of mass production of the subject electrical motors or generator.

  7. Hypermedia as medium

    NASA Technical Reports Server (NTRS)

    Dede, Christopher J.

    1990-01-01

    Claims and rebuttals that hypermedia (the associative, nonlinear interconnection of multimedia materials) is a fundamentally innovative means of thinking and communicating are described. This representational architecture has many advantages that make it a major advance over other media; however, it also has several intrinsic problems that severly limits its effectiveness as a medium. These advantages and limits in applications are discussed.

  8. Holographic recording medium

    NASA Technical Reports Server (NTRS)

    Gange, Robert Allen (Inventor)

    1977-01-01

    A holographic recording medium comprising a conductive substrate, a photoconductive layer and an electrically alterable layer of a linear, low molecular weight hydrocarbon polymer has improved fatigue resistance. An acrylic barrier layer can be interposed between the photoconductive and electrically alterable layers.

  9. Fresnel reflection from a cavity with net roundtrip gain

    SciTech Connect

    Mansuripur, Tobias S.; Mansuripur, Masud

    2014-03-24

    A planewave incident on an active etalon with net roundtrip gain may be expected to diverge in field amplitude, yet applying the Fresnel formalism to Maxwell's equations admits a convergent solution. We describe this solution mathematically and provide additional insight by demonstrating the response of such a cavity to an incident beam of light. Cavities with net roundtrip gain have often been overlooked in the literature, and a clear understanding of their behavior yields insight to negative refraction in nonmagnetic media, a duality between loss and gain, amplified total internal reflection, and the negative-index lens.

  10. Reply to Comment on ``Effects of fast and slow solar wind on the correlations between interplanetary medium and geomagnetic activity'' by C. B. Wang and J. K. Chao

    NASA Astrophysics Data System (ADS)

    Ballatore, Paola

    2003-10-01

    The paper [2002] (the paper commented) shows that the statistical significance of the correlations between the interplanetary parameters and the geomagnetic indices (Kp or Dst) is generally less significant during the fastest solar wind. On the other hand, at these fast solar wind periods, the significance of the Kp versus Dst correlation is equal to or higher than during slower solar wind. These results, together with further observations related to substorm periods and with previously published findings, are interpreted in terms of a difference in the interplanetary-magnetospheric coupling for solar wind faster or slower than a certain threshold (identified between about 500 and 600 km/s). Specifically, it is suggested that a possible linear approximation of the geomagnetic-interplanetary coupling is more appropriate during solar wind speed (Vsw) slower than this threshold, being nonlinear processes more dominant during the fastest speeds. This reply highlights that the correlation coefficients shown by [2003] are in agreement with these findings. In addition, Wang and Chao show that the statistical significance of the difference between the correlation coefficients for Vsw ≥ 550 km/s and those for Vsw < 550 km/s would indicate that the interplanetary-geomagnetic correlations during the fastest speeds are not significantly different from those at slower Vsw ranges. Here we give evidence of the fact that according to the common definition of this parameter, the calculation of the significance of the difference between two correlation coefficients made by Wang and Chao is wrong. Moreover, Wang and Chao recalculate the correlations between the interplanetary parameters and the ΔDst instead of Dst; in fact they note that the time derivative of this index (not the index itself) is driven by the interplanetary medium. Here we note that on the contrary, they show that the correlation coefficients between interplanetary parameters and Dst are larger than those

  11. A new Vitreoscilla filiformis extract grown on spa water-enriched medium activates endogenous cutaneous antioxidant and antimicrobial defenses through a potential Toll-like receptor 2/protein kinase C, zeta transduction pathway.

    PubMed

    Mahe, Yann F; Perez, Marie-Jesus; Tacheau, Charlotte; Fanchon, Chantal; Martin, Richard; Rousset, Françoise; Seite, Sophie

    2013-01-01

    Vitreoscilla filiformis (VF) biomass (VFB) has been widely used in cosmetic preparations and shown to modulate the major inducible free-radical scavenger mitochondrial superoxide dismutase in skin cells. By adding La Roche-Posay (LRP) thermal spring water to the VF culture medium, we obtained a biomass (LRP-VFB) with a similar mitochondrial superoxide dismutase activation capacity to VF. Also, the new biomass more powerfully stimulated mRNA expression and antimicrobial peptides in reconstructed epidermis. Interestingly, a predictive computer model that analyzed transducing events within skin epidermal cells suggested that this protective activity may involve the Toll-like receptor 2/protein kinase C, zeta transduction pathway. Protein kinase C, zeta inhibition was effectively shown to abolish VFB-induced gene stimulation and confirmed this hypothesis. This thus opens new avenues for investigation into the improvement of skin homeostatic defense in relation to the control of its physiological microbiota and innate immunity. PMID:24039440

  12. Catalase-like activity of bovine met-hemoglobin: interaction with the pseudo-catalytic peroxidation of anthracene traces in aqueous medium.

    PubMed

    Paco, Laveille; Galarneau, Anne; Drone, Jullien; Fajula, François; Bailly, Carole; Pulvin, Sylviane; Thomas, Daniel

    2009-10-01

    Hemoglobin is a member of the hemoprotein superfamily whose main role is to transport O(2) in vertebrate organisms. It has two known promiscuous enzymatic activities, peroxidase and oxygenase. Here we show for the first time that bovine hemoglobin also presents a catalase-like activity characterized by a V(max )of 344 microM/min, a K(M )of 24 mM and a k(cat) equal to 115/min. For high anthracene and hemoglobin concentrations and low hydrogen peroxide concentrations, this activity inhibits the expected oxidation of anthracene, which occurs through a peroxidase-like mechanism. Anthracene belongs to the polycyclic aromatic hydrocarbon (PAH) family whose members are carcinogenic and persistent pollutants found in industrial waste waters. Our results show that anthracene oxidation by hemoglobin and hydrogen peroxide follows a typical bi-bi ping-pong mechanism with a V(max) equal to 0.250 microM/min, K(M(H2O2) )of 80 microM, K(M(ANT)) of 1.1 microM and k(cat) of 0.17/min. The oxidation of anthracene is shown to be pseudo-catalytic because an excess of hemoglobin and hydrogen peroxide is required to make PAH completely disappear. Thus, bovine hemoglobin presents, in different degrees, all the catalytic activities of the hemoprotein group, which makes it a very interesting protein for biotechnological processes and one with which structure-activity relationships can be studied. PMID:19606432

  13. Collaborative Manufacturing for Small-Medium Enterprises

    NASA Astrophysics Data System (ADS)

    Irianto, D.

    2016-02-01

    Manufacturing systems involve decisions concerning production processes, capacity, planning, and control. In a MTO manufacturing systems, strategic decisions concerning fulfilment of customer requirement, manufacturing cost, and due date of delivery are the most important. In order to accelerate the decision making process, research on decision making structure when receiving order and sequencing activities under limited capacity is required. An effective decision making process is typically required by small-medium components and tools maker as supporting industries to large industries. On one side, metal small-medium enterprises are expected to produce parts, components or tools (i.e. jigs, fixture, mold, and dies) with high precision, low cost, and exact delivery time. On the other side, a metal small- medium enterprise may have weak bargaining position due to aspects such as low production capacity, limited budget for material procurement, and limited high precision machine and equipment. Instead of receiving order exclusively, a small-medium enterprise can collaborate with other small-medium enterprise in order to fulfill requirements high quality, low manufacturing cost, and just in time delivery. Small-medium enterprises can share their best capabilities to form effective supporting industries. Independent body such as community service at university can take a role as a collaboration manager. The Laboratory of Production Systems at Bandung Institute of Technology has implemented shared manufacturing systems for small-medium enterprise collaboration.

  14. Information gains from cosmological probes

    NASA Astrophysics Data System (ADS)

    Grandis, S.; Seehars, S.; Refregier, A.; Amara, A.; Nicola, A.

    2016-05-01

    In light of the growing number of cosmological observations, it is important to develop versatile tools to quantify the constraining power and consistency of cosmological probes. Originally motivated from information theory, we use the relative entropy to compute the information gained by Bayesian updates in units of bits. This measure quantifies both the improvement in precision and the `surprise', i.e. the tension arising from shifts in central values. Our starting point is a WMAP9 prior which we update with observations of the distance ladder, supernovae (SNe), baryon acoustic oscillations (BAO), and weak lensing as well as the 2015 Planck release. We consider the parameters of the flat ΛCDM concordance model and some of its extensions which include curvature and Dark Energy equation of state parameter w. We find that, relative to WMAP9 and within these model spaces, the probes that have provided the greatest gains are Planck (10 bits), followed by BAO surveys (5.1 bits) and SNe experiments (3.1 bits). The other cosmological probes, including weak lensing (1.7 bits) and {H0} measures (1.7 bits), have contributed information but at a lower level. Furthermore, we do not find any significant surprise when updating the constraints of WMAP9 with any of the other experiments, meaning that they are consistent with WMAP9. However, when we choose Planck15 as the prior, we find that, accounting for the full multi-dimensionality of the parameter space, the weak lensing measurements of CFHTLenS produce a large surprise of 4.4 bits which is statistically significant at the 8 σ level. We discuss how the relative entropy provides a versatile and robust framework to compare cosmological probes in the context of current and future surveys.

  15. Nucleus accumbens response to gains in reputation for the self relative to gains for others predicts social media use.

    PubMed

    Meshi, Dar; Morawetz, Carmen; Heekeren, Hauke R

    2013-01-01

    Our reputation is important to us; we've experienced natural selection to care about our reputation. Recently, the neural processing of gains in reputation (positive social feedback concerning one's character) has been shown to occur in the human ventral striatum. It is still unclear, however, how individual differences in the processing of gains in reputation may lead to individual differences in real-world behavior. For example, in the real-world, one way that people currently maintain their reputation is by using social media websites, like Facebook. Furthermore, Facebook use consists of a social comparison component, where users observe others' behavior and can compare it to their own. Therefore, we hypothesized a relationship between the way the brain processes specifically self-relevant gains in reputation and one's degree of Facebook use. We recorded functional neuroimaging data while participants received gains in reputation, observed the gains in reputation of another person, or received monetary reward. We demonstrate that across participants, when responding to gains in reputation for the self, relative to observing gains for others, reward-related activity in the left nucleus accumbens predicts Facebook use. However, nucleus accumbens activity in response to monetary reward did not predict Facebook use. Finally, a control step-wise regression analysis showed that Facebook use primarily explains our results in the nucleus accumbens. Overall, our results demonstrate how individual sensitivity of the nucleus accumbens to the receipt of self-relevant social information leads to differences in real-world behavior. PMID:24009567

  16. Nucleus accumbens response to gains in reputation for the self relative to gains for others predicts social media use

    PubMed Central

    Meshi, Dar; Morawetz, Carmen; Heekeren, Hauke R.

    2013-01-01

    Our reputation is important to us; we've experienced natural selection to care about our reputation. Recently, the neural processing of gains in reputation (positive social feedback concerning one's character) has been shown to occur in the human ventral striatum. It is still unclear, however, how individual differences in the processing of gains in reputation may lead to individual differences in real-world behavior. For example, in the real-world, one way that people currently maintain their reputation is by using social media websites, like Facebook. Furthermore, Facebook use consists of a social comparison component, where users observe others' behavior and can compare it to their own. Therefore, we hypothesized a relationship between the way the brain processes specifically self-relevant gains in reputation and one's degree of Facebook use. We recorded functional neuroimaging data while participants received gains in reputation, observed the gains in reputation of another person, or received monetary reward. We demonstrate that across participants, when responding to gains in reputation for the self, relative to observing gains for others, reward-related activity in the left nucleus accumbens predicts Facebook use. However, nucleus accumbens activity in response to monetary reward did not predict Facebook use. Finally, a control step-wise regression analysis showed that Facebook use primarily explains our results in the nucleus accumbens. Overall, our results demonstrate how individual sensitivity of the nucleus accumbens to the receipt of self-relevant social information leads to differences in real-world behavior. PMID:24009567

  17. Effect of various nitrogen salts in beet pulp medium on polygalacturonase activity of Penicillium sp. 7/4B/EI 1 mutant.

    PubMed

    Szajer, I

    1978-01-01

    The highest PG activity was obtained in beet pulp with (NH4)2HPO4 in amount equivalent to 0.14--0.28% N after 7 days of growth; At optimal concentration, (NH4)2HPO4 did not influence the biomass production, but increased the pH of the culture media to above 6.0. The PG was an extracellular enzyme, acting mainly on highly esterified pectin. The attack was of a random manner, characteristic for the endo-enzymes. The enzyme was active at temperature 20 degrees C--40 degrees C and pH 5.0--6.0. PMID:81597

  18. An enzyme containing microemulsion based on skin friendly oil and surfactant as decontamination medium for organo phosphates: phase behavior, structure, and enzyme activity.

    PubMed

    Stehle, Ralf; Schulreich, Christoph; Wellert, Stefan; Gäb, Jürgen; Blum, Marc-Michael; Kehe, Kai; Richardt, Andras; Lapp, Alain; Hellweg, Thomas

    2014-01-01

    The present contribution presents a microemulsion system containing cosmetic oil and sugar surfactant and the enzyme diisopropyl fluorophosphatase (DFPase) as active agent for the decontamination of human skin. The bicontinuous structure and the physical properties of the microemulsion are characterized by dynamic light scattering and small angle neutron scattering. The DFPase from the squid Loligo vulgaris is catalyzing the hydrolysis of highly toxic organophosphates. The effect of the enzyme on the structure of the microemulsion is investigated. Moreover, the enzyme/microemulsion system is also studied with respect to its activity using nuclear magnetic resonance spectroscopy leading to promising results. A fast decomposition of the nerve agent sarin is achieved. PMID:24183440

  19. Teaching and Technology for the Cutting Edge Practitioner: Lesson Plans and Supplementary Activities for the Classroom Teacher Who Uses English as a Medium of Instruction.

    ERIC Educational Resources Information Center

    Canning-Wilson, Christine, Ed.

    This book contains 44 chapters and an appendix of pictures for teachers to use with Arab learners in Higher Colleges of Technology (HCT) classrooms. Each lesson describes goals, materials needed, and the activity. Many lessons offer sample worksheets, answers to anticipated problems, alternative uses, and suggestions for optimal utilization. With…

  20. PHYSICAL EFFECTS OCCURRING DURING GENERATION AND AMPLIFICATION OF LASER RADIATION: Kinetic model of the active medium of an XeCl laser pumped by an electron beam

    NASA Astrophysics Data System (ADS)

    Boĭchenko, A. M.; Derzhiev, V. I.; Zhidkov, A. G.; Yakovlenko, Sergei I.

    1989-02-01

    Kinetic models of active media of an XeCl laser are developed for the case when these media are diluted by various buffer gases (helium, neon, argon) and the laser is pumped by an electron beam. The results of the calculations are in satisfactory agreement with experimental data.

  1. A Technology-Mediated Behavioral Weight Gain Prevention Intervention for College Students: Controlled, Quasi-Experimental Study

    PubMed Central

    Monroe, Courtney M; Turner-McGrievy, Gabrielle; Sundstrom, Beth; Larsen, Chelsea; Magradey, Karen; Wilcox, Sara; Brandt, Heather M

    2016-01-01

    Background Both men and women are vulnerable to weight gain during the college years, and this phenomenon is linked to an increased risk of several chronic diseases and mortality. Technology represents an attractive medium for the delivery of weight control interventions focused on college students, given its reach and appeal among this population. However, few technology-mediated weight gain prevention interventions have been evaluated for college students. Objective This study examined a new technology-based, social media-facilitated weight gain prevention intervention for college students. Methods Undergraduates (n =58) in two sections of a public university course were allocated to either a behavioral weight gain prevention intervention (Healthy Weight, HW; N=29) or a human papillomavirus (HPV) vaccination awareness intervention (control; N=29). All students were enrolled, regardless of initial body weight or expressed interest in weight management. The interventions delivered 8 lessons via electronic newsletters and Facebook postings over 9 weeks, which were designed to foster social support and introduce relevant educational content. The HW intervention targeted behavioral strategies to prevent weight gain and provided participants with a Wi-Fi-enabled scale and an electronic physical activity tracker to facilitate weight regulation. A repeated-measures analysis of variance was conducted to examine within- and between-group differences in measures of self-reported weight control practices and objectively measured weight. Use of each intervention medium and device was objectively tracked, and intervention satisfaction measures were obtained. Results Students remained weight stable (HW: −0.48+1.9 kg; control: −0.45+1.4 kg), with no significant difference between groups over 9 weeks (P =.94). However, HW students reported a significantly greater increase in the number of appropriate weight control strategies than did controls (2.1+4.5 vs −1

  2. Liquid chromatographic extraction medium

    DOEpatents

    Horwitz, E.P.; Dietz, M.L.

    1994-09-13

    A method and apparatus are disclosed for extracting strontium and technetium values from biological, industrial and environmental sample solutions using a chromatographic column. An extractant medium for the column is prepared by generating a solution of a diluent containing a Crown ether and dispersing the solution on a resin substrate material. The sample solution is highly acidic and is introduced directed to the chromatographic column and strontium or technetium is eluted using deionized water. 1 fig.

  3. Liquid chromatographic extraction medium

    DOEpatents

    Horwitz, E. Philip; Dietz, Mark L.

    1994-01-01

    A method and apparatus for extracting strontium and technetium values from biological, industrial and environmental sample solutions using a chromatographic column is described. An extractant medium for the column is prepared by generating a solution of a diluent containing a Crown ether and dispersing the solution on a resin substrate material. The sample solution is highly acidic and is introduced directed to the chromatographic column and strontium or technetium is eluted using deionized water.

  4. Waves in Interstellar Medium

    NASA Astrophysics Data System (ADS)

    Kamaya, H.

    1998-03-01

    Many hydrodynamical researches have been developed. Especially, analysis of the compressible flow is significantly improved by interstellar physicists. To obtain sufficient appreciation, we should not analyze only the effect of self-gravity of the system but also consider the property of inhomogeneity of the interstellar medium. I stress that another hydrodynamical approach is appreciated. That is the multi-phase-flow method. In the astrophysical context, there are few preliminary works of it. I intend to develop it in more suitable method for the interstellar physics. This dissertation is only the first step for me. But, fundamental properties of the multi-phase-flow are presented, considering the effect of compressibility, self-(and/or mutual) gravity, and friction between two phases. All of these properties are generally important to examine the origin, destruction and the global distribution of interstellar medium. My motivation is trying to delve into the global properties of the interstellar medium. The method of multi-phase-flow has great advantage for my aim, and its usefulness has been shown in this thesis.

  5. Culture Medium for Enterobacteria

    PubMed Central

    Neidhardt, Frederick C.; Bloch, Philip L.; Smith, David F.

    1974-01-01

    A new minimal medium for enterobacteria has been developed. It supports growth of Escherichia coli and Salmonella typhimurium at rates comparable to those of any of the traditional media that have high phosphate concentrations, but each of the macronutrients (phosphate, sulfate, and nitrogen) is present at a sufficiently low level to permit isotopic labeling. Buffering capacity is provided by an organic dipolar ion, morpholinopropane sulfonate, which has a desirable pK (7.2) and no apparent inhibitory effect on growth. The medium has been developed with the objectives of (i) providing reproducibility of chemical composition, (ii) meeting the experimentally determined nutritional needs of the cell, (iii) avoiding an unnecessary excess of the major ionic species, (iv) facilitating the adjustment of the levels of individual ionic species, both for isotopic labeling and for nutritional studies, (v) supplying a complete array of micronutrients, (vi) setting a particular ion as the crop-limiting factor when the carbon and energy source is in excess, and (vii) providing maximal convenience in the manufacture and storage of the medium. PMID:4604283

  6. Relation between transmission and energy stored in random media with gain

    NASA Astrophysics Data System (ADS)

    Payne, Ben; Andreasen, Jonathan; Cao, Hui; Yamilov, Alexey

    2010-09-01

    In this work, we investigate a possibility of using the ratio between optical transmission, T , and energy stored inside the system, E , as a quantitative measure of the enhanced mesoscopic corrections to diffusive transport of light through a random medium with gain. We obtain an expression for T/E as a function of amplification strength in the diffusive approximation and show that it does not a have tendency to diverge when the threshold for random lasing is approached, as both T and E do. Furthermore, we find that a change in T/E signifies a change in the electric field distribution inside the random medium. In the localization regime, we also investigate the correlations between transmission and energy stored in the medium with and without amplification. Our results suggest that T/E is a promising parameter which can help characterize the nature of wave transport in random medium with gain.

  7. Steering, splitting, and cloning of an optical beam in a coherently driven Raman gain system

    NASA Astrophysics Data System (ADS)

    Verma, Onkar N.; Dey, Tarak N.

    2015-01-01

    We propose an all-optical antiwaveguide mechanism for steering, splitting, and cloning of an optical beam without diffraction. We use a spatially inhomogeneous pump beam to create an antiwaveguide structure in a Doppler broadened N -type four-level Raman gain medium for a copropagating weak probe beam. We show that a transverse modulated index of refraction and gain due to the spatially dependent pump beam hold the keys to steering, splitting, and cloning of an optical beam. We have also shown that an additional control field permits the propagation of an optical beam through an otherwise gain medium without diffraction and instability. We further discuss how finesse of the cloned images can be increased by changing the detuning of the control field. We arrive at similar results by using homogeneously broadened gain media at higher density.

  8. Effects of Collaborative Group Composition and Inquiry Instruction on Reasoning Gains and Achievement in Undergraduate Biology

    PubMed Central

    Jensen, Jamie Lee; Lawson, Anton

    2011-01-01

    This study compared the effectiveness of collaborative group composition and instructional method on reasoning gains and achievement in college biology. Based on initial student reasoning ability (i.e., low, medium, or high), students were assigned to either homogeneous or heterogeneous collaborative groups within either inquiry or didactic instruction. Achievement and reasoning gains were assessed at the end of the semester. Inquiry instruction, as a whole, led to significantly greater gains in reasoning ability and achievement. Inquiry instruction also led to greater confidence and more positive attitudes toward collaboration. Low-reasoning students made significantly greater reasoning gains within inquiry instruction when grouped with other low reasoners than when grouped with either medium or high reasoners. Results are consistent with equilibration theory, supporting the idea that students benefit from the opportunity for self-regulation without the guidance or direction of a more capable peer. PMID:21364101

  9. All-optical switching of localized surface plasmon resonance in single gold nanosandwich using GeSbTe film as an active medium

    SciTech Connect

    Hira, T.; Homma, T.; Uchiyama, T.; Kuwamura, K.; Kihara, Y.; Saiki, T.

    2015-01-19

    Localized surface plasmon resonance (LSPR) switching was investigated in a Au/GeSbTe/Au nanosandwich as a key active element for plasmonic integrated circuits and devices. Near-infrared single-particle spectroscopy was conducted to examine the interaction of a Au nanorod (AuNR) and Au film, between which a GeSbTe layer was incorporated as an active phase-change media. Numerical calculation revealed that hybridized modes of the AuNR and Au film exhibit a significant change of scattering intensity with the phase change. In particular, the antisymmetric (magnetic resonance) mode can be modulated effectively by the extinction coefficient of GST, as well as its refractive index. Experimental demonstration of the switching operation was performed by alternate irradiation with a picosecond pulsed laser for amorphization and a continuous wave laser for crystallization. Repeatable modulation was obtained by monitoring the scattering light around the LSPR peak at λ = 1070 nm.

  10. All-optical switching of localized surface plasmon resonance in single gold nanosandwich using GeSbTe film as an active medium

    NASA Astrophysics Data System (ADS)

    Hira, T.; Homma, T.; Uchiyama, T.; Kuwamura, K.; Kihara, Y.; Saiki, T.

    2015-01-01

    Localized surface plasmon resonance (LSPR) switching was investigated in a Au/GeSbTe/Au nanosandwich as a key active element for plasmonic integrated circuits and devices. Near-infrared single-particle spectroscopy was conducted to examine the interaction of a Au nanorod (AuNR) and Au film, between which a GeSbTe layer was incorporated as an active phase-change media. Numerical calculation revealed that hybridized modes of the AuNR and Au film exhibit a significant change of scattering intensity with the phase change. In particular, the antisymmetric (magnetic resonance) mode can be modulated effectively by the extinction coefficient of GST, as well as its refractive index. Experimental demonstration of the switching operation was performed by alternate irradiation with a picosecond pulsed laser for amorphization and a continuous wave laser for crystallization. Repeatable modulation was obtained by monitoring the scattering light around the LSPR peak at λ = 1070 nm.

  11. Gain control in the sonar of odontocetes.

    PubMed

    Ya Supin, Alexander; Nachtigall, Paul E

    2013-06-01

    The sonar of odontocetes processes echo-signals within a wide range of echo levels. The level of echoes varies widely by tens of decibels depending on the level of the emitted sonar pulse, the target strength, the distance to the target, and the sound absorption by the water media. The auditory system of odontocetes must be capable of effective perception, analysis, and discrimination of echo-signals within all this variability. The sonar of odontocetes has several mechanisms to compensate for the echo-level variation (gain control). To date, several mechanisms of the biosonar gain control have been revealed in odontocetes: (1) adjustment of emitted sonar pulse levels (the longer the distance to the target, the higher the level of the emitted pulse), (2) short-term variation of hearing sensitivity based on forward masking of the echo by the preceding self-heard emitted pulse and subsequent release from the masking, and (3) active long-term control of hearing sensitivity. Recent investigations with the use of the auditory evoked-potential technique have demonstrated that these mechanisms effectively minimize the variation of the response to the echo when either the emitted sonar pulse level, or the target distance, or both vary within a wide range. A short review of these data is presented herein. PMID:23132646

  12. Risk Insights Gained from Fire Incidents

    SciTech Connect

    Kazarians, Mardy; Nowlen, Steven P.

    1999-06-10

    There now exist close to 20 years of history in the application of Probabilistic Risk Assessment (PRA) for the analysis of fire risk at nuclear power plants. The current methods are based on various assumptions regarding fire phenomena, the impact of fire on equipment and operator response, and the overall progression of a fire event from initiation through final resolution. Over this same time period, a number of significant fire incidents have occurred at nuclear power plants around the world. Insights gained from US experience have been used in US studies as the statistical basis for establishing fire initiation frequencies both as a function of the plant area and the initiating fire source.To a lesser extent, the fire experience has also been used to assess the general severity and duration of fires. However, aside from these statistical analyses, the incidents have rarely been scrutinized in detail to verify the underlying assumptions of fire PRAs. This paper discusses an effort, under which a set of fire incidents are being reviewed in order to gain insights directly relevant to the methods, data, and assumptions that form the basis for current fire PRAs. The paper focuses on the objectives of the effort, the specific fire events being reviews methodology, and anticipated follow-on activities.

  13. A comparative investigation of metal-support interactions on the catalytic activity of Pt nanoparticles for ethanol oxidation in alkaline medium

    NASA Astrophysics Data System (ADS)

    Godoi, Denis R. M.; Villullas, Hebe M.; Zhu, Fu-Chun; Jiang, Yan-Xia; Sun, Shi-Gang; Guo, Junsong; Sun, Lili; Chen, Rongrong

    2016-04-01

    The effects of interactions of Pt nanoparticles with hybrid supports on reactivity towards ethanol oxidation in alkaline solution are investigated. Studies involve catalysts with identical Pt nanoparticles on six hybrid supports containing carbon powder and transition metal oxides (TiO2, ZrO2, SnO2, CeO2, MoO3 and WO3). In situ X-ray absorption spectroscopy (XAS) results evidence that metal-support interactions produce changes in the Pt 5d band vacancy, which appears to determine the catalytic activity. The highest and lowest activities are observed for Pt nanoparticles on hybrid supports containing TiO2 and CeO2, respectively. Further studies are presented for these two catalysts. In situ FTIR reflection spectroscopy measurements, taken using both multi-stepped FTIR spectroscopy (MS-FTIR) and single potential alteration FTIR spectroscopy (SPA-FTIR), evidence that the main product of ethanol oxidation is acetate, although signals attributed to carbonate and CO2 indicate some differences in CO2 production. Fuel cell performances of these catalysts, tested in a 4.5 cm2 single cell at different temperatures (40-90 °C) show good agreement with data obtained by electrochemical techniques. Results of this comprehensive study point out the possibility of compensating a reduction of noble metal load with an increase in activity promoted by interactions between metallic nanoparticles and a support.

  14. CCD Side 2 Gain Ratio Test

    NASA Astrophysics Data System (ADS)

    Dressel, Linda

    2002-07-01

    Observe a bright spectrophotometric standard star at the center of the detector with a wide slit {52x2} with the 3 low dispersion gratings at gain 1 and gain 4, so that the ratio of gain 4 to gain 1 can be measured. {This will be used to calibrate gain 4 relative to gain 1, which is already well measured.} Read out some additional exposures through non-default amplifier B, which is used for some calibration programs, so that the gains of amp B relative to amp D can be measured. Place the target at row 900, close to the D amplifier and far from the B amplifier, then take long and short exposures with G230LB with both amplifiers, so that CTE can be measured over a broad range of counts. With gain 4/1, amp B/D, and CTE known from these measurements, find the sensitivity at row 900 relative to the central row.

  15. Gain assisted nanocomposite multilayers with near zero permittivity modulus at visible frequencies

    NASA Astrophysics Data System (ADS)

    Rizza, Carlo; Di Falco, Andrea; Ciattoni, Alessandro

    2011-11-01

    We have fabricated a nano-laminate by alternating metal and gain medium layers, the gain dielectric consisting of a polymer incorporating optically pumped dye molecules. From standard reflection-transmission experiments, we show that, at a visible wavelength, both the real and the imaginary parts of the permittivity ɛ∥ attain very small values and we measure, at λ = 604 nm, |ɛ∥|=0.04 which is 21.5% smaller than its value in the absence of optical pumping. Our investigation thus proves that a medium with a permittivity with very small modulus, a key condition promising efficient subwavelength optical steering, can be actually synthesized.

  16. Nonlinearity-induced PT-symmetry without material gain

    NASA Astrophysics Data System (ADS)

    Miri, Mohammad-Ali; Alù, Andrea

    2016-06-01

    Parity-time symmetry has raised a great deal of attention in optics in recent years, yet its application has been so far hindered by the stringent requirements on coherent gain balanced with loss. In this paper, we show that the conditions to enable parity and time symmetry can be simultaneously satisfied for a pair of modes with mixed frequencies interacting in a nonlinear medium, without requiring the presence of material gain. First, we consider a guided wave structure with second order nonlinearity and we derive the PT-symmetric Hamiltonian that governs the interaction of two waves of mixed frequencies when accompanied by a high intensity pump beam at the sum frequency. We also extend the results to an array of coupled nonlinear waveguide channels. It is shown that the evolution dynamics of the low-frequency waves is associated with a periodic PT-symmetric lattice while the phase of the pump beams can be utilized as a control parameter to modify the gain and loss distribution, thus realizing different PT lattices by design. Our results suggest that nonlinear wave mixing processes can form a rich platform to realize PT-symmetric Hamiltonians of arbitrary dimensions in optical systems, without requiring material gain.

  17. Achieving yield gains in wheat.

    PubMed

    Reynolds, Matthew; Foulkes, John; Furbank, Robert; Griffiths, Simon; King, Julie; Murchie, Erik; Parry, Martin; Slafer, Gustavo

    2012-10-01

    Wheat provides 20% of calories and protein consumed by humans. Recent genetic gains are <1% per annum (p.a.), insufficient to meet future demand. The Wheat Yield Consortium brings expertise in photosynthesis, crop adaptation and genetics to a common breeding platform. Theory suggest radiation use efficiency (RUE) of wheat could be increased ~50%; strategies include modifying specificity, catalytic rate and regulation of Rubisco, up-regulating Calvin cycle enzymes, introducing chloroplast CO(2) concentrating mechanisms, optimizing light and N distribution of canopies while minimizing photoinhibition, and increasing spike photosynthesis. Maximum yield expression will also require dynamic optimization of source: sink so that dry matter partitioning to reproductive structures is not at the cost of the roots, stems and leaves needed to maintain physiological and structural integrity. Crop development should favour spike fertility to maximize harvest index so phenology must be tailored to different photoperiods, and sensitivity to unpredictable weather must be modulated to reduce conservative responses that reduce harvest index. Strategic crossing of complementary physiological traits will be augmented with wide crossing, while genome-wide selection and high throughput phenotyping and genotyping will increase efficiency of progeny screening. To ensure investment in breeding achieves agronomic impact, sustainable crop management must also be promoted through crop improvement networks. PMID:22860982

  18. Electrocatalytic oxidation of small organic molecules in acid medium: enhancement of activity of noble metal nanoparticles and their alloys by supporting or modifying them with metal oxides

    PubMed Central

    Kulesza, Pawel J.; Pieta, Izabela S.; Rutkowska, Iwona A.; Wadas, Anna; Marks, Diana; Klak, Karolina; Stobinski, Leszek; Cox, James A.

    2013-01-01

    Different approaches to enhancement of electrocatalytic activity of noble metal nanoparticles during oxidation of small organic molecules (namely potential fuels for low-temperature fuel cells such as methanol, ethanol and formic acid) are described. A physical approach to the increase of activity of catalytic nanoparticles (e.g. platinum or palladium) involves nanostructuring to obtain highly dispersed systems of high surface area. Recently, the feasibility of enhancing activity of noble metal systems through the formation of bimetallic (e.g. PtRu, PtSn, and PdAu) or even more complex (e.g. PtRuW, PtRuSn) alloys has been demonstrated. In addition to possible changes in the electronic properties of alloys, specific interactions between metals as well as chemical reactivity of the added components have been postulated. We address and emphasize here the possibility of utilization of noble metal and alloyed nanoparticles supported on robust but reactive high surface area metal oxides (e.g. WO3, MoO3, TiO2, ZrO2, V2O5, and CeO2) in oxidative electrocatalysis. This paper concerns the way in which certain inorganic oxides and oxo species can act effectively as supports for noble metal nanoparticles or their alloys during electrocatalytic oxidation of hydrogen and representative organic fuels. Among important issues are possible changes in the morphology and dispersion, as well as specific interactions leading to the improved chemisorptive and catalytic properties in addition to the feasibility of long time operation of the discussed systems. PMID:24443590

  19. Effect of solvent viscosity on the anisotropy of distribution of excited centers in an active medium of a dye laser at a pump power near the threshold value

    SciTech Connect

    Yartsev, A.I.; Sechkarev, A.V.

    1995-03-01

    Dependences of the anisotropy of the distribution of excited centers (A) in rhodamine 6G and 6-aminophenolenon solutions in organic solvents of different viscosity are studied. Relying on the character of the dependence of A on the viscosity, the conclusion is made that it is possible to employ a relation similar to the Levshin-Perrin formula for polarized luminescence in the threshold excitation mode. Experimental data are used to calculate angles between absorption and emission dipoles of electron auxochrome groups of molecules for the dyes under investigation and to estimate the effective volume of activator molecules for the ethanol solution of rhodamine 6G. 6 refs., 1 fig.

  20. Microscopic analysis of non-equilibrium dynamics in the semiconductor-laser gain medium

    SciTech Connect

    Hader, J.; Moloney, J. V.; Koch, S. W.

    2014-04-14

    Fully microscopic many-body calculations are used to analyze the carrier dynamics in situations where a strong sub-picosecond pulse interacts with an inverted semiconductor quantum well. Electron-electron and electron-phonon scatterings are calculated on a second Born-Markov level. Intra-subband scatterings on a scale of tens of femtoseconds are shown to quickly re-fill the kinetic holes created in the carrier distributions during the pulse amplification. Even for sub-100 fs pulses, this significantly influences the pulse amplification as well as its spectral dependence. Interband scatterings on a few picosecond timescale limit the possibly achievable repetition rate in pulsed semiconductor lasers.

  1. Yb:FAP and related materials, laser gain medium comprising same, and laser systems using same

    DOEpatents

    Krupke, W.F.; Payne, S.A.; Chase, L.L.; Smith, L.K.

    1994-01-18

    An ytterbium doped laser material remarkably superior to all others, including Yb:YAG, comprises ytterbium doped apatite (Yb:Ca[sub 5](PO[sub 4])[sub 3]F) or Yb:FAP, or ytterbium doped crystals that are structurally related to FAP. The new laser material is used in laser systems pumped by diode pump sources having an output near 0.905 microns or 0.98 microns, such as InGaAs and AlInGaAs, or other narrowband pump sources near 0.905 microns or 0.98 microns. The laser systems are operated in either the conventional or ground state depletion mode. 9 figures.

  2. Yb:FAP and related materials, laser gain medium comprising same, and laser systems using same

    DOEpatents

    Krupke, William F.; Payne, Stephen A.; Chase, Lloyd L.; Smith, Larry K.

    1994-01-01

    An ytterbium doped laser material remarkably superior to all others, including Yb:YAG, comprises Ytterbium doped apatite (Yb:Ca.sub.5 (PO.sub.4).sub.3 F) or Yb:FAP, or ytterbium doped crystals that are structurally related to FAP. The new laser material is used in laser systems pumped by diode pump sources having an output near 0.905 microns or 0.98 microns, such as InGaAs and AlInGaAs, or other narrowband pump sources near 0.905 microns or 0.98 microns. The laser systems are operated in either the conventional or ground state depletion mode.

  3. Mechanisms of the Rosetta high gain antenna

    NASA Astrophysics Data System (ADS)

    Pereira, Carlos

    2001-09-01

    This paper describes the antenna pointing mechanism (APM) and the hold down and release mechanism (HRM) used in the high gain antenna of the ROSETTA mission. The hold down and release mechanism consists of three units which compensate the tolerance mismatch between antenna and spacecraft through incorporation of potting rings. Given that the activation mode is pyrotechnic, release shock is a major concern and is minimised through integration of shock absorbers which allow stroking of the separation nuts. The antenna pointing mechanism is a dual drive (azimuth over elevation) unit which allows controlled rotation of the antenna. The drive units incorporate spring loaded end stops to prevent the antenna from hitting the spacecraft, and optical encoders which register the absolute position of the antenna. The pointing and the hold down mechanisms of the ROSETTA antenna are fully qualified and will withstand the high launch loads of the Ariane-5 and the environmental demands of deep space operation.

  4. Gaining Public Support for RFI Mitigation

    NASA Astrophysics Data System (ADS)

    Finley, D. G.

    2004-05-01

    Astronomy's access to radio spectrum depends to a great extent on international and national regulatory agencies. Such regulation is inherently a political process, so support for radio astronomy by the general public is vital to success. Educating the public about a subject perceived as so highly technical can be challenging. Success in advancing public understanding of the issue and gaining public support is based on two foundations: publicizing the societal value of astronomy; and explaining the interference problem in non-technical terms that draw upon the well-understood terminology of environmental protection. Effective communication can convince non-scientists that astronomical research is a vital and beneficial activity, and that unpolluted access to the radio spectrum is essential to making the new discoveries that are astronomy's contribution to humanity. Convinced of this, the public will support imposing the expense of engineering measures designed to protect radio astronomy, just as they support spending money to protect air, water and soil from pollution.

  5. Gestational weight gain among Hispanic women.

    PubMed

    Sangi-Haghpeykar, Haleh; Lam, Kim; Raine, Susan P

    2014-01-01

    To describe gestational weight gain among Hispanic women and to examine psychological, social, and cultural contexts affecting weight gain. A total of 282 Hispanic women were surveyed post-partum before leaving the hospital. Women were queried about their prepregnancy weight and weight gained during pregnancy. Adequacy of gestational weight gain was based on guidelines set by the Institute of Medicine in 2009. Independent risk factors for excessive or insufficient weight gain were examined by logistic regression. Most women were unmarried (59 %), with a mean age of 28.4 ± 6.6 years and an average weight gain of 27.9 ± 13.3 lbs. Approximately 45 % of women had gained too much, 32 % too little, and only 24 % had an adequate amount of weight gain. The mean birth weight was 7.3, 7.9, and 6.8 lbs among the adequate, excessive, and insufficient weight gain groups. Among women who exercised before pregnancy, two-thirds continued to do so during pregnancy; the mean gestational weight gain of those who continued was lower than those who stopped (26.8 vs. 31.4 lbs, p = 0.04). Independent risk factors for excessive weight gain were being unmarried, U.S. born, higher prepregnancy body mass index, and having indifferent or negative views about weight gain. Independent risk factors for insufficient weight gain were low levels of support and late initiation of prenatal care. Depression, stress, and a woman's or her partner's happiness regarding pregnancy were unrelated to weight gain. The results of this study can be used by prenatal programs to identify Hispanic women at risk for excessive or insufficient gestational weight gain. PMID:23456347

  6. Observation of polarized gain from aligned colloidal nanorods

    NASA Astrophysics Data System (ADS)

    Gao, Yuan; Ta, Van Duong; Zhao, Xin; Wang, Yue; Chen, Rui; Mutlugun, Evren; Fong, Kah Ee; Tan, Swee Tiam; Dang, Cuong; Sun, Xiao Wei; Sun, Handong; Demir, Hilmi Volkan

    2015-04-01

    In recent years, colloidal semiconductor nanorods have attracted great interest for polarized spontaneous emission. However, their polarized gain has not been possible to achieve so far. In this work we show the highly polarized stimulated emission from the densely packed ensembles of core-seeded nanorods in a cylindrical cavity. Here CdSe/CdS dot-in-rods were coated and aligned on the inner wall of a capillary tube, providing optical feedback for the nanorod gain medium. Results show that the polarized gain originates intrinsically from the aligned nanorods and not from the cavity and that the optical anisotropy of the nanorod ensemble was amplified with the capillary tube, resulting in highly polarized whispering gallery mode lasing. The highly polarized emission and lasing, together with easy fabrication and flexible incorporation, make this microlaser a promising candidate for important color conversion and enrichment applications including liquid crystal display backlighting and laser lighting.In recent years, colloidal semiconductor nanorods have attracted great interest for polarized spontaneous emission. However, their polarized gain has not been possible to achieve so far. In this work we show the highly polarized stimulated emission from the densely packed ensembles of core-seeded nanorods in a cylindrical cavity. Here CdSe/CdS dot-in-rods were coated and aligned on the inner wall of a capillary tube, providing optical feedback for the nanorod gain medium. Results show that the polarized gain originates intrinsically from the aligned nanorods and not from the cavity and that the optical anisotropy of the nanorod ensemble was amplified with the capillary tube, resulting in highly polarized whispering gallery mode lasing. The highly polarized emission and lasing, together with easy fabrication and flexible incorporation, make this microlaser a promising candidate for important color conversion and enrichment applications including liquid crystal display

  7. The Interstellar Medium

    NASA Technical Reports Server (NTRS)

    Tielens, Alexander G. G. M.

    1995-01-01

    The Interstellar Medium (ISM) forms an integral part of the lifecycle of stars and the galaxy. Stars are formed by gravitational contraction of interstellar clouds. Over their life, stars return much of their mass to the ISM through winds and supernova explosions, resulting in a slow enrichment in heavy elements. Understanding the origin and evolution of the ISM is a key problem within astrophysics. The KAO has made many important contributions to studies of the interstellar medium both on the macro and on the micro scale. In this overview, I will concentrate on two breakthroughs in the last decade in which KAO observations have played a major role: (1) the importance of large Polycyclic Aromatic Hydrocarbon (PAH) molecules for the ISM (section 3) and (2) the study of Photodissociation Regions (PDRs) as an analog for the diffuse ISM at large (section 4). Appropriately, the micro and macro problem are intricately interwoven in these problems. Finally, section 5 reviews the origin of the (CII) emission observed by COBE.

  8. The Local Interstellar Medium

    NASA Astrophysics Data System (ADS)

    Redfield, S.

    2006-09-01

    The Local Interstellar Medium (LISM) is a unique environment that presents an opportunity to study general interstellar phenomena in great detail and in three dimensions. In particular, high resolution optical and ultraviolet spectroscopy have proven to be powerful tools for addressing fundamental questions concerning the physical conditions and three-dimensional (3D) morphology of this local material. After reviewing our current understanding of the structure of gas in the solar neighborhood, I will discuss the influence that the LISM can have on stellar and planetary systems, including LISM dust deposition onto planetary atmospheres and the modulation of galactic cosmic rays through the astrosphere --- the balancing interface between the outward pressure of the magnetized stellar wind and the inward pressure of the surrounding interstellar medium. On Earth, galactic cosmic rays may play a role as contributors to ozone layer chemistry, planetary electrical discharge frequency, biological mutation rates, and climate. Since the LISM shares the same volume as practically all known extrasolar planets, the prototypical debris disks systems, and nearby low-mass star-formation sites, it will be important to understand the structures of the LISM and how they may influence planetary atmospheres.

  9. DENSE MEDIUM CYCLONE OPTIMIZATON

    SciTech Connect

    Gerald H. Luttrell; Chris J. Barbee; Peter J. Bethell; Chris J. Wood

    2005-06-30

    Dense medium cyclones (DMCs) are known to be efficient, high-tonnage devices suitable for upgrading particles in the 50 to 0.5 mm size range. This versatile separator, which uses centrifugal forces to enhance the separation of fine particles that cannot be upgraded in static dense medium separators, can be found in most modern coal plants and in a variety of mineral plants treating iron ore, dolomite, diamonds, potash and lead-zinc ores. Due to the high tonnage, a small increase in DMC efficiency can have a large impact on plant profitability. Unfortunately, the knowledge base required to properly design and operate DMCs has been seriously eroded during the past several decades. In an attempt to correct this problem, a set of engineering tools have been developed to allow producers to improve the efficiency of their DMC circuits. These tools include (1) low-cost density tracers that can be used by plant operators to rapidly assess DMC performance, (2) mathematical process models that can be used to predict the influence of changes in operating and design variables on DMC performance, and (3) an expert advisor system that provides plant operators with a user-friendly interface for evaluating, optimizing and trouble-shooting DMC circuits. The field data required to develop these tools was collected by conducting detailed sampling and evaluation programs at several industrial plant sites. These data were used to demonstrate the technical, economic and environmental benefits that can be realized through the application of these engineering tools.

  10. Interactional behavior of the polyelectrolyte poly sodium 4-styrene sulphonate (NaPSS) with imidazolium based surface active ionic liquids in an aqueous medium.

    PubMed

    Sharma, Renu; Kamal, Ajar; Kang, Tejwant Singh; Mahajan, Rakesh Kumar

    2015-09-28

    The present study aims to develop an understanding of the interactions between an anionic polyelectrolyte, poly sodium 4-styrene sulphonate (NaPSS), and cationic surface active imidazolium based ionic liquids (SAILs), [Cnmim][Cl] (n = 10, 12, 14) using a multi-technique approach. Various physicochemical and electrochemical techniques such as surface tension, conductivity, fluorescence, isothermal titration calorimetry (ITC), dynamic light scattering (DLS), turbidity, potentiometry, cyclic voltammetry (CV), and differential pulse voltammetry (DPV) are employed to obtain comprehensive information about NaPSS-SAIL interactions. Different stages of interaction, corresponding to the critical aggregation concentration (cac), critical saturation concentration (Cs) and critical micelle concentration (cmc) have been observed owing to the strong electrostatic and hydrophobic interactions, and the results obtained from different techniques complement each other very well. The results extracted from DLS and turbidity measurements clearly indicated that the size of the micelle like aggregates first decreases and then increases in the presence of polyelectrolyte. The binding isotherms obtained using potentiometry show a concentration dependence and the highly co-operative nature of the interactions which is attributed to aggregation of the polyelectrolyte-SAIL complexes. The diffusion coefficients (Dm) of the electroactive probe in the pure and NaPSS-SAIL mixed systems were obtained, which were further used to obtain the values of the micellar self-diffusion coefficients (D) and inter-micellar interaction parameters (kd). PMID:26300416

  11. Radio Is an Educational Medium.

    ERIC Educational Resources Information Center

    Duby, Aliza

    This report summarizes information found in a survey of the literature on radio as an educational medium which covered the published literature from many areas of the world. Comments on the literature reviewed are provided throughout the text, which is organized under seven major headings: (1) Radio, Mass Medium; (2) Radio, the Medium (broadening…

  12. Weight gain prevention and smoking cessation: cautionary findings.

    PubMed Central

    Hall, S M; Tunstall, C D; Vila, K L; Duffy, J

    1992-01-01

    OBJECTIVES. Weight gain is a consistent sequela of smoking cessation. A successful intervention might attract smokers who fear weight gain. If the gain causes smoking relapse, such an intervention might reduce smoking relapse risk. METHODS. Using a sample of 158 smokers who completed a 2-week smoking treatment program, we compared an innovative weight gain prevention intervention with both a nonspecific treatment and standard treatment. Subjects were assessed on weight and smoking behavior and followed for 1 year. RESULTS. A disturbing, unexpected finding was that subjects in both the innovative and nonspecific conditions had a higher risk of smoking relapse than did standard treatment subjects. Some differences were observed between abstinent and smoking subjects in weight gain by treatment condition. CONCLUSIONS. Both active interventions may have been so complicated that they detracted from nonsmoking. Also, caloric restriction may increase the reinforcing value of nicotine, a psychoactive drug, thereby increasing smoking relapse risk. The magnitude of weight gain after smoking cessation may not merit interventions that increase smoking risk. Perhaps attitudinal modifications are the most appropriate. PMID:1585959

  13. Radiation cooling and gain calculation for C VI 182 A line in C/Se plasma

    SciTech Connect

    Nam, C.H.; Valeo, E.; Suckewer, S.; Feldman, U.

    1986-04-01

    A model is developed which is capable of describing the evolution of gain resulting from both rapid radiative and expansion cooling of a recombining, freely expanding plasma. It is demonstrated for the particular case of a carbon/selenium plasma that the cooling rate which leads to optimal gain can be achieved by adjusting the admixture of an efficiently radiating material (selenium) in the gain medium (carbon). Comparison is made to a recent observation of gain in a recent NRL/Rochester experiment with carbon/selenium plasma for the n = 3 ..-->.. 2 transition in C VI occurring at 182 A. The predicted maximum gain is approx.10 cm/sup -1/, as compared to observation of 2 to 3 cm/sup -1/.

  14. Coherent control in quantum dot gain media using shaped pulses: a numerical study.

    PubMed

    Mishra, Akhilesh Kumar; Karni, Ouri; Eisenstein, Gadi

    2015-11-16

    We present a numerical study of coherent control in a room temperature InAs/InP quantum dot (QD) semiconductor optical amplifier (SOA) using shaped ultra-short pulses. Both the gain and absorption regimes were analyzed for pulses with central wavelengths lying on either side of the inhomogeneously broadened gain spectrum. The numerical experiments predict that in the gain regime the coherent interactions between a QD SOA and a pulse can be controlled by incorporating a quadratic spectral phase (QSP) in the pulse profile. The sequential interaction with the gain medium of different spectral components of the pulse results in either suppression or enhancement of the coherent signatures on the pulse profile depending upon their proximity to the gain spectrum peak. In the absorption regime, positive QSP induces a negative chirp that adds up to that of a two photon absorption induced Kerr-like effect resulting in pulse compression while negative QSP enhances dispersive broadening of the pulse. PMID:26698476

  15. Microchannel plate modal gain variations with temperature

    NASA Technical Reports Server (NTRS)

    Slater, David C.; Timothy, J. G.

    1993-01-01

    Measurements of the modal gain of two high-gain curved-channel microchannel plates (MCPs) at various operating temperatures are presented. Both MCPs were fabricated from the Long Life glass with 12-micron diam channels on 15-micron centers. The modal gain was found to decrease with increasing temperature at a rate of -0.1 percent C. This reduction of gain with temperature is attributed primarily to an axial temperature gradient along each MCP channel creating a nonuniform electric field within the channel that lowers the effective output gain. A lowering of the secondary electron yield resulting from increased phonon scattering of secondary electrons released within the walls of the MCP channels was assessed, but was found to have a negligible contribution to the drop in gain with temperature.

  16. Proprioceptive feedback determines visuomotor gain in Drosophila.

    PubMed

    Bartussek, Jan; Lehmann, Fritz-Olaf

    2016-01-01

    Multisensory integration is a prerequisite for effective locomotor control in most animals. Especially, the impressive aerial performance of insects relies on rapid and precise integration of multiple sensory modalities that provide feedback on different time scales. In flies, continuous visual signalling from the compound eyes is fused with phasic proprioceptive feedback to ensure precise neural activation of wing steering muscles (WSM) within narrow temporal phase bands of the stroke cycle. This phase-locked activation relies on mechanoreceptors distributed over wings and gyroscopic halteres. Here we investigate visual steering performance of tethered flying fruit flies with reduced haltere and wing feedback signalling. Using a flight simulator, we evaluated visual object fixation behaviour, optomotor altitude control and saccadic escape reflexes. The behavioural assays show an antagonistic effect of wing and haltere signalling on visuomotor gain during flight. Compared with controls, suppression of haltere feedback attenuates while suppression of wing feedback enhances the animal's wing steering range. Our results suggest that the generation of motor commands owing to visual perception is dynamically controlled by proprioception. We outline a potential physiological mechanism based on the biomechanical properties of WSM and sensory integration processes at the level of motoneurons. Collectively, the findings contribute to our general understanding how moving animals integrate sensory information with dynamically changing temporal structure. PMID:26909184

  17. Proprioceptive feedback determines visuomotor gain in Drosophila

    PubMed Central

    Bartussek, Jan; Lehmann, Fritz-Olaf

    2016-01-01

    Multisensory integration is a prerequisite for effective locomotor control in most animals. Especially, the impressive aerial performance of insects relies on rapid and precise integration of multiple sensory modalities that provide feedback on different time scales. In flies, continuous visual signalling from the compound eyes is fused with phasic proprioceptive feedback to ensure precise neural activation of wing steering muscles (WSM) within narrow temporal phase bands of the stroke cycle. This phase-locked activation relies on mechanoreceptors distributed over wings and gyroscopic halteres. Here we investigate visual steering performance of tethered flying fruit flies with reduced haltere and wing feedback signalling. Using a flight simulator, we evaluated visual object fixation behaviour, optomotor altitude control and saccadic escape reflexes. The behavioural assays show an antagonistic effect of wing and haltere signalling on visuomotor gain during flight. Compared with controls, suppression of haltere feedback attenuates while suppression of wing feedback enhances the animal’s wing steering range. Our results suggest that the generation of motor commands owing to visual perception is dynamically controlled by proprioception. We outline a potential physiological mechanism based on the biomechanical properties of WSM and sensory integration processes at the level of motoneurons. Collectively, the findings contribute to our general understanding how moving animals integrate sensory information with dynamically changing temporal structure. PMID:26909184

  18. Edge cladding gain media according to IL-11317

    SciTech Connect

    Soules, T

    2005-02-10

    In this patent application we wish to claim the following approach to ameliorating spontaneous amplified emission (ASE) that occurs in a laser amplifier slab. There are two important elements of our approach. We wish to claim the application of both together but not either one alone. (1) The first element of the invention is to roughen the edge surfaces of the amplifier slab. A rough surface with random planar features larger than the wavelength of light will reflect and refract incident light rays at angles different than the median plane of the surface. The rough surface can then be characterized by two parameters. First there is a distribution of heights about the zero mean plane of the surface. If normal this distribution is characterized by a standard deviation. The second parameter is the correlation distance that describes how close together on average are the peaks and valleys. The ratio of these two numbers determines the spread of light reflected off the surface of the edge of the slab. (2) The second element in our invention is to bond the roughened edges of the gain medium to an ASE absorbing media using a suitable bonding agent. In order for the ASE to leave the gain medium crystal there must be minimal reflection and maximum transmission at the interface. This requires having a near match of the index of refraction of the bonding medium and the amplifier slab material at the wavelength of the ASE. Further if the index of refraction of the bonding agent is less than that of the amplifier there will be some total internal reflection even if the surface is roughened. The index of refraction of GGG is {approx} 1.92 and that of YAG is {approx} 1.84. There are no suitable bonding agents with indices of refraction this high.

  19. Gestational weight gain trajectories in primary care

    PubMed Central

    Piccinini-Vallis, Helena; Lee-Baggley, Dayna; Stewart, Moira; Ryan, Bridget

    2016-01-01

    Objective To identify gestational weight gain trajectories, stratified by prepregnancy body mass index (BMI), of women with singleton pregnancies who received prenatal care in a primary care setting, and to compare these trajectories with the 2009 Institute of Medicine gestational weight gain recommendations. Design Retrospective cohort study. Setting Halifax, NS. Participants Women who received prenatal care at the Dalhousie Family Medicine clinics in Halifax from 2009 to 2013. Main outcome measures For each prenatal visit, gestational age and weight measurements were obtained. Multilevel modeling was used to analyze the gestational weight gain trajectories. The upper limit of the guideline-recommended weekly gestational weight gain was compared with the 95% CI of the observed mean weekly gestational weight gain for each prepregnancy BMI category. Results A total of 280 women were included in the analyses. There was a significant interaction between prepregnancy BMI category and gestational weight gain over time (P < .001), with gestational weight gain being significantly lower among women with prepregnancy BMI of 30.0 kg/m2 or greater compared with those with BMI of 18.5 to less than 25.0 kg/m2 and 25.0 to less than 30.0 kg/m2. When comparing women’s weight gain with the recommendations, women with prepregnancy BMI of 25.0 to less than 30.0 kg/m2 had the most guideline discordance, deviating from the weight gain recommendations at 20 weeks’ gestation. Conclusion These results are relevant and of benefit to women and clinicians wishing to address excess gestational weight gain, and to researchers and policy makers developing interventions aimed at curbing gestational weight gain in primary care. Although our results showed women with prepregnancy BMI of 25.0 to less than 30.0 kg/m2 gained the most excess, guideline-discordant weight, interventions should target all women planning or experiencing a pregnancy.

  20. Characterization of site-specific mutations in a short-chain-length/medium-chain-length polyhydroxyalkanoate synthase: in vivo and in vitro studies of enzymatic activity and substrate specificity.

    PubMed

    Chuah, Jo-Ann; Tomizawa, Satoshi; Yamada, Miwa; Tsuge, Takeharu; Doi, Yoshiharu; Sudesh, Kumar; Numata, Keiji

    2013-06-01

    Saturation point mutagenesis was carried out at position 479 in the polyhydroxyalkanoate (PHA) synthase from Chromobacterium sp. strain USM2 (PhaC(Cs)) with specificities for short-chain-length (SCL) [(R)-3-hydroxybutyrate (3HB) and (R)-3-hydroxyvalerate (3HV)] and medium-chain-length (MCL) [(R)-3-hydroxyhexanoate (3HHx)] monomers in an effort to enhance the specificity of the enzyme for 3HHx. A maximum 4-fold increase in 3HHx incorporation and a 1.6-fold increase in PHA biosynthesis, more than the wild-type synthase, was achieved using selected mutant synthases. These increases were subsequently correlated with improved synthase activity and increased preference of PhaC(Cs) for 3HHx monomers. We found that substitutions with uncharged residues were beneficial, as they resulted in enhanced PHA production and/or 3HHx incorporation. Further analysis led to postulations that the size and geometry of the substrate-binding pocket are determinants of PHA accumulation, 3HHx fraction, and chain length specificity. In vitro activities for polymerization of 3HV and 3HHx monomers were consistent with in vivo substrate specificities. Ultimately, the preference shown by wild-type and mutant synthases for either SCL (C(4) and C(5)) or MCL (C(6)) substrates substantiates the fundamental classification of PHA synthases. PMID:23584780