Giant impacts in the Beta Pic system

NASA Astrophysics Data System (ADS)

Jackson, A.

2014-09-01

One scenario that can potentially explain the brightness asymmetry in the Beta Pictoris debris disk in the mid-infrared and millimetre is that of a comparatively recent (< 1 Myr ago) impact between planetary scale bodies at an orbital distance of ˜85 AU, as discussed by Dent et al 2014. I will discuss the details of this model, how it applies to Beta Pictoris, and how it may be applied elsewhere.

Probing the young circumplanetary environment of Beta Pic b during transit egress

NASA Astrophysics Data System (ADS)

Wang, Jason

2017-08-01

Among the thousands of known exoplanets, Beta Pic b is the only directly imaged exoplanet with a nearly edge-on orbit. We show that the latest astrometric measurements rule out a transit by the planet at 10-sigma significance, but we are certain that the Hill sphere of the planet will transit. With a period of 22 years and no other system like it, this Hill sphere transit provides a rare opportunity to study the evolving circumplanetary environment of a young and well-characterized exoplanet. To compliment GO-14621, our Cycle 25 proposal to monitor the ingress of the Hill sphere, we propose a modest HST program to photometrically search for signatures of the planet's large scale circumplanetary material during the egress of the Hill sphere transit. The existence of such material is plausible given that Beta Pic's young age is similar to that of the ring-bearing J1407b system. Combined with GO-14621 and less-precise but dedicated ground-based monitoring, these observations will give us a comprehensive set of observations about this young circumplanetary environment. Given the sparse observational data of circumplanetary environments, non-detections will also be valuable for constraining the timescales relevant to circumplanetary material and moon formation. If photometric variations are detected with HST, these results would yield empirical information concerning the dynamics of the system and the evolution of planetary systems as a whole.

Beta Pic observations requested for BRITE-Constellation

NASA Astrophysics Data System (ADS)

Waagen, Elizabeth O.

2017-01-01

The AAVSO is part of the BRITE-Constellation Ground Based Observations Team (GBOT), supporting cutting-edge science from the BRITE-Constellation satellites and coordinating with BRITE-Constellation scientist Dr. Konstanze Zwintz (Universitaet Innsbruck) and her team. The delta Scuti star beta Pic (NSV 16683) (3.80-3.86V) is one of the BRITE stars being focused on during this season. Bet Pic is particularly interesting now because a transit of the star's planet's Hill sphere (the region around a planet in which it dominates the attraction of satellites) is predicted to occur during 2017-2018. Ongoing observations beginning now are valuable to establish a baseline prior to the transit. The AAVSO's webpage on the BRITE target stars was updated in November with information on bet Pic from Dr. Zwintz. AAVSO observers with appropriate equipment and located at a southern enough latitude are encouraged to observe bet Pic. Its brightness makes bet Pic well suited to PEP and DSLR photometry; CCD photometry is also possible. However, great care must be taken by all observers, especially those using CCD, to avoid saturation. As the amplitude of this star is very small, visual observations are very difficult, but they are welcome. Multicolor (BVR) photometry better than 0.01 magnitude and time-series observations with a cadence of a few minutes (less than 10 minutes) are requested beginning now and continuing at least through 2017 and likely through 2018. The precision and cadence required are essential in order for the data to be most useful for studying the transit. Spectroscopists wishing to participate should submit their spectra directly to Dr. Konstanze Zwintz (konstanze.zwintz@uibk.ac.at). Finder charts with sequence may be created using the AAVSO Variable Star Plotter (https://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details.

Gyrokinetic and kinetic particle-in-cell simulations of guide-field reconnection. I. Macroscopic effects of the electron flows

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

Muñoz, P. A., E-mail: munozp@mps.mpg.de; Kilian, P.; Büchner, J.

In this work, we compare gyrokinetic (GK) with fully kinetic Particle-in-Cell (PIC) simulations of magnetic reconnection in the limit of strong guide field. In particular, we analyze the limits of applicability of the GK plasma model compared to a fully kinetic description of force free current sheets for finite guide fields (b{sub g}). Here, we report the first part of an extended comparison, focusing on the macroscopic effects of the electron flows. For a low beta plasma (β{sub i} = 0.01), it is shown that both plasma models develop magnetic reconnection with similar features in the secondary magnetic islands if a sufficientlymore » high guide field (b{sub g} ≳ 30) is imposed in the kinetic PIC simulations. Outside of these regions, in the separatrices close to the X points, the convergence between both plasma descriptions is less restrictive (b{sub g} ≳ 5). Kinetic PIC simulations using guide fields b{sub g} ≲ 30 reveal secondary magnetic islands with a core magnetic field and less energetic flows inside of them in comparison to the GK or kinetic PIC runs with stronger guide fields. We find that these processes are mostly due to an initial shear flow absent in the GK initialization and negligible in the kinetic PIC high guide field regime, in addition to fast outflows on the order of the ion thermal speed that violate the GK ordering. Since secondary magnetic islands appear after the reconnection peak time, a kinetic PIC/GK comparison is more accurate in the linear phase of magnetic reconnection. For a high beta plasma (β{sub i} = 1.0) where reconnection rates and fluctuations levels are reduced, similar processes happen in the secondary magnetic islands in the fully kinetic description, but requiring much lower guide fields (b{sub g} ≲ 3)« less

Low Mass Members in Nearby Young Moving Groups Revealed

NASA Astrophysics Data System (ADS)

Schlieder, Joshua; Simon, Michal; Rice, Emily; Lepine, Sebastien

2010-08-01

We are now ready to expand our program that identifies highly probable low-mass members of the nearby young moving groups (NYMGs) to stars of mass ~ 0.1 Msun. This is important 1) To provide high priority targets for exoplanet searches by direct imaging, 2) To complete the census of the membership in the NYMGs, and 3) To provide a well-characterized sample of nearby young stars for detailed study of their physical properties and multiplicity (the median distances of the (beta) Pic and AB Dor groups are ~ 35 pc with ages ~ 12 and 50 Myr respectively). Our proven technique starts with a proper motion selection algorithm, proceeds to vet the sample for indicators of youth, and requires as its last step the measurement of candidate member radial velocities (RVs). So far, we have obtained all RV measurements with the high resolution IR spectrometer at the NASA-IRTF and have reached the limits of its applicability. To identify probable new members in the south, and also those of the lowest mass, we need the sensitivity of PHOENIX at Gemini-S and NIRSPEC at Keck-II.

Dust disks around Vega-type stars

NASA Astrophysics Data System (ADS)

Chini, R.; Kruegel, E.; Kreysa, E.; Shustov, B.; Tutukov, A.

1991-12-01

This study presents 1300-micron observations of the circumstellar dust around Vega-type stars. A comparison of the new data (24-arcsec HPBW) for Alpha PsA, Tau-1 Eri and Epsilon Eri with previous measurements made at an angular resolution of 11-arcsec shows that the dust emission is extended. From measurements at different positions it is concluded that the circumstellar dust around Beta Pic does not exceed the size of the optical disk of 500 AU. A model for Beta Pic that fits optical as well as IR data is discussed. Finally, a scenario for the evolution of circumstellar grains is suggested where, on one side, the Poynting-Robertson effect removes the small particles and, on the other side, collisions lead to the formation of larger bodies. Time-dependent IR spectra in reasonable agreement with observations are presented.

Dynamical mass measurement of the young spectroscopic binary V343 Normae AaAb resolved with the Gemini Planet Imager

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

Nielsen, Eric L.; De Rosa, Robert J.; Wang, Jason

Here, we present new spatially resolved astrometry and photometry from the Gemini Planet Imager of the inner binary of the young multiple star system V343 Normae, which is a member of the β Pictoris (β Pic) moving group. V343 Normae comprises a K0 and mid-M star in a ~4.5 year orbit (AaAb) and a wide 10'' M5 companion (B). By combining these data with archival astrometry and radial velocities we fit the orbit and measure individual masses for both components ofmore » $${M}_{\\mathrm{Aa}}=1.10\\pm 0.10\\,{M}_{\\odot }$$ and $${M}_{\\mathrm{Ab}}=0.290\\pm 0.018\\,{M}_{\\odot }$$. Comparing to theoretical isochrones, we find good agreement for the measured masses and JHK band magnitudes of the two components consistent with the age of the β Pic moving group. We derive a model-dependent age for the β Pic moving group of 26 ± 3 Myr by combining our results for V343 Normae with literature measurements for GJ 3305, which is another group member with resolved binary components and dynamical masses.« less

Dynamical mass measurement of the young spectroscopic binary V343 Normae AaAb resolved with the Gemini Planet Imager

DOE PAGES

Nielsen, Eric L.; De Rosa, Robert J.; Wang, Jason; ...

2016-11-22

Here, we present new spatially resolved astrometry and photometry from the Gemini Planet Imager of the inner binary of the young multiple star system V343 Normae, which is a member of the β Pictoris (β Pic) moving group. V343 Normae comprises a K0 and mid-M star in a ~4.5 year orbit (AaAb) and a wide 10'' M5 companion (B). By combining these data with archival astrometry and radial velocities we fit the orbit and measure individual masses for both components ofmore » $${M}_{\\mathrm{Aa}}=1.10\\pm 0.10\\,{M}_{\\odot }$$ and $${M}_{\\mathrm{Ab}}=0.290\\pm 0.018\\,{M}_{\\odot }$$. Comparing to theoretical isochrones, we find good agreement for the measured masses and JHK band magnitudes of the two components consistent with the age of the β Pic moving group. We derive a model-dependent age for the β Pic moving group of 26 ± 3 Myr by combining our results for V343 Normae with literature measurements for GJ 3305, which is another group member with resolved binary components and dynamical masses.« less

Electron Acceleration in the Magnetotail during Substorms in Semi-Global PIC Simulations

NASA Astrophysics Data System (ADS)

Richard, R. L.; Schriver, D.; Ashour-Abdalla, M.; El-Alaoui, M.; Lapenta, G.; Walker, R. J.

2015-12-01

To understand the acceleration of electrons during a substorm reconnection event we have applied a semi-global particle in cell (PIC) simulation box embedded within a global magnetohydrodynamic (MHD) simulation of Earth's magnetosphere for an event on February 15, 2008. The MHD results were used to populate the PIC simulation and to set the boundary conditions. In the magnetotail we found that a series of dipolarizations formed due to unsteady reconnection. We also found that the most energetic electrons were in the separatrices far from the x-point. We attributed the acceleration to a streaming instability in the separatrices. To further understand electron acceleration we have applied the large scale kinetic (LSK) technique in which tens- to hundreds- of thousands of electrons are followed within the electric and magnetic fields from the PIC simulations., Electrons are already included in the PIC simulation, but the LSK simulations will allow selected individual particles to be followed and analyzed. Initially we performed electron LSK calculations in a two dimensional version of the PIC simulation in which electrons were allowed to move in the ignorable cross tail direction. These LSK calculations showed that electrons gained energy primarily for two reasons: (1) acceleration by the average dawn to dusk electric field and (2) acceleration by intense but localized electric field structures. The overall electron transport was more dawnward than duskward due to the average electric field. At the same time electrons typically moved away from the reconnection region in both the earthward and tailward directions. Superimposed on this large-scale transport was motion in both the dusk and dawn directions across the tail because of the electric field structures, which were particularly intense in the separatrices. LSK calculations are now being carried out by using the full three-dimensional magnetic and electric fields from the PIC simulation and these results will be compared with the two-dimensional results for the same substorm event.

10 micron Spectroscopy with OSCIR: Silicate Minerology and The Origins of Disks & Protoplanetesimals

NASA Astrophysics Data System (ADS)

Woodward, Chick; Wooden, Diane; Harker, David; Rodgers, Bernadette; Butner, Harold

1999-02-01

The analysis of the silicate mineralogy of pre-main sequence Herbig Ae/Be (HeAeBe) stars to main sequence (beta)-Pic systems, probes the chemical and physical conditions in these potentially planet-forming environments, the condensation of dust from the gas-disk, and the aggregation and accretion of these solids into planetesimals and comets. We propose to obtain 10 micron OSCIR spectra of a selected list of HeAeBe and (beta)-Pic like systems. Use of our ground-based data, combined with the ISO SWS database, and our extensive analytical modeling efforts will permit us to develop a fundamental understanding of connections between silicate mineralogy and the origins and evolution of disks and protoplanetesimals. This program will provide a framework to extend our understanding of planetary formation processes and the mineralogy of dust in differing circumstellar environs and comets to be studied with the NASA STARDUST and SIRTF missions.

p-( sup 125 I)iodoclonidine is a partial agonist at the alpha 2-adrenergic receptor

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

Gerhardt, M.A.; Wade, S.M.; Neubig, R.R.

1990-08-01

The binding properties of p-(125I)iodoclonidine (( 125I)PIC) to human platelet membranes and the functional characteristics of PIC are reported. (125I)PIC bound rapidly and reversibly to platelet membranes, with a first-order association rate constant (kon) at room temperature of 8.0 +/- 2.7 x 10(6) M-1 sec-1 and a dissociation rate constant (koff) of 2.0 +/- 0.8 x 10(-3) sec-1. Scatchard plots of specific (125I)PIC binding (0.1-5 nM) were linear, with a Kd of 1.2 +/- 0.1 nM. (125I)PIC bound to the same number of high affinity sites as the alpha 2-adrenergic receptor (alpha 2-AR) full agonist (3H) bromoxidine (UK14,304), which representedmore » approximately 40% of the sites bound by the antagonist (3H)yohimbine. Guanosine 5'-(beta, gamma-imido)triphosphate greatly reduced the amount of (125I)PIC bound (greater than 80%), without changing the Kd of the residual binding. In competition experiments, the alpha 2-AR-selective ligands yohimbine, bromoxidine, oxymetazoline, clonidine, p-aminoclonidine, (-)-epinephrine, and idazoxan all had Ki values in the low nanomolar range, whereas prazosin, propranolol, and serotonin yielded Ki values in the micromolar range. Epinephrine competition for (125I)PIC binding was stereoselective. Competition for (3H)bromoxidine binding by PIC gave a Ki of 1.0 nM (nH = 1.0), whereas competition for (3H)yohimbine could be resolved into high and low affinity components, with Ki values of 3.7 and 84 nM, respectively. PIC had minimal agonist activity in inhibiting adenylate cyclase in platelet membranes, but it potentiated platelet aggregation induced by ADP with an EC50 of 1.5 microM. PIC also inhibited epinephrine-induced aggregation, with an IC50 of 5.1 microM. Thus, PIC behaves as a partial agonist in a human platelet aggregation assay. (125I)PIC binds to the alpha 2B-AR in NG-10815 cell membranes with a Kd of 0.5 +/- 0.1 nM.« less

A 2D electrostatic PIC code for the Mark III Hypercube

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

Ferraro, R.D.; Liewer, P.C.; Decyk, V.K.

We have implemented a 2D electrostastic plasma particle in cell (PIC) simulation code on the Caltech/JPL Mark IIIfp Hypercube. The code simulates plasma effects by evolving in time the trajectories of thousands to millions of charged particles subject to their self-consistent fields. Each particle`s position and velocity is advanced in time using a leap frog method for integrating Newton`s equations of motion in electric and magnetic fields. The electric field due to these moving charged particles is calculated on a spatial grid at each time by solving Poisson`s equation in Fourier space. These two tasks represent the largest part ofmore » the computation. To obtain efficient operation on a distributed memory parallel computer, we are using the General Concurrent PIC (GCPIC) algorithm previously developed for a 1D parallel PIC code.« less

Simulation of High-Beta Plasma Confinement

NASA Astrophysics Data System (ADS)

Font, Gabriel; Welch, Dale; Mitchell, Robert; McGuire, Thomas

2017-10-01

The Lockheed Martin Compact Fusion Reactor concept utilizes magnetic cusps to confine the plasma. In order to minimize losses through the axial and ring cusps, the plasma is pushed to a high-beta state. Simulations were made of the plasma and magnetic field system in an effort to quantify particle confinement times and plasma behavior characteristics. Computations are carried out with LSP using implicit PIC methods. Simulations of different sub-scale geometries at high-Beta fusion conditions are used to determine particle loss scaling with reactor size, plasma conditions, and gyro radii. ©2017 Lockheed Martin Corporation. All Rights Reserved.

The properties of the gas around beta Pictoris

NASA Astrophysics Data System (ADS)

Roberge, A.

2014-09-01

Debris disks are often described as gas-free. Compared to protoplanetary disks, they do in general have low gas abundances, as evidenced by the very few detections of sub-mm CO emission from bona fide debris disks to date. However, some debris disks do contain low levels of detectable gas, typically seen in absorption against the stellar spectrum at UV and optical wavelengths. Of all debris disks, the gas in the Beta Pic disk is the best characterized and understood. Here, I describe those characteristics and explain our current understanding of the nature of the gas. Like the dust, the gas is secondary material coming from planetesimal destruction, and provides opportunities for sensitive probes of the bulk composition of young planetary bodies. The gas can also be a sensitive tracer of disk asymmetries and dynamical interactions, as shown by new ALMA observations of CO emission from Beta Pic (see attached infographic and YouTube video explaining the discovery). Very likely, every debris disk contains its due portion of gas, but how much that is, we do not yet know. We are poised to answer this question with the advent of ALMA. With its unprecedented sensitivity and spatial resolution, ALMA may usher in a golden age for general studies of debris gas.

Packaging of silicon photonic devices: from prototypes to production

NASA Astrophysics Data System (ADS)

Morrissey, Padraic E.; Gradkowski, Kamil; Carroll, Lee; O'Brien, Peter

2018-02-01

The challenges associated with the photonic packaging of silicon devices is often underestimated and remains technically challenging. In this paper, we review some key enabling technologies that will allow us to overcome the current bottleneck in silicon photonic packaging; while also describing the recent developments in standardisation, including the establishment of PIXAPP as the worlds first open-access PIC packaging and assembly Pilot Line. These developments will allow the community to move from low volume prototype photonic packaged devices to large scale volume manufacturing, where the full commercialisation of PIC technology can be realised.

Freeing data through The Polar Information Commons

NASA Astrophysics Data System (ADS)

de Bruin, T.; Chen, R. S.; Parsons, M. A.; Carlson, D. J.; Cass, K.; Finney, K.; Wilbanks, J.; Jochum, K.

2010-12-01

The polar regions are changing rapidly with dramatic global effect. Wise management of resources, improved decision support, and effective international cooperation on resource and geopolitical issues require deeper understanding and better prediction of these changes. Unfortunately, polar data and information remain scattered, scarce, and sporadic. Inspired by the Antarctic Treaty of 1959 that established the Antarctic as a global commons to be used only for peaceful purposes and scientific research, we assert that data and information about the polar regions are themselves “public goods” that should be shared ethically and with minimal constraint. ICSU’s Committee on Data (CODATA) therefore started the Polar Information Commons (PIC) as an open, virtual repository for vital scientific data and information. The PIC provides a shared, community-based cyber-infrastructure fostering innovation, improving scientific efficiency, and encouraging participation in polar research, education, planning, and management. The PIC builds on the legacy of the International Polar Year (IPY), providing a long-term framework for access to and preservation of both existing and future data and information about the polar regions. Rapid change demands rapid data access. The PIC system enables scientists to quickly expose their data to the world and share them through open protocols on the Internet. A PIC digital label will alert users and data centers to new polar data and ensure that usage rights are clear. The PIC utilizes the Science Commons Protocol for Implementing Open Access Data, which promotes open data access through the public domain coupled with community norms of practice to ensure use of data in a fair and equitable manner. A set of PIC norms has been developed in consultation with key polar data organizations and other stakeholders. We welcome inputs from the broad science community as we further develop and refine the PIC approach and move ahead with implementation.

Phase locked multiple rings in the radiation pressure ion acceleration process

NASA Astrophysics Data System (ADS)

Wan, Y.; Hua, J. F.; Pai, C.-H.; Li, F.; Wu, Y. P.; Lu, W.; Zhang, C. J.; Xu, X. L.; Joshi, C.; Mori, W. B.

2018-04-01

Laser contrast plays a crucial role for obtaining high quality ion beams in the radiation pressure ion acceleration (RPA) process. Through one- and two-dimensional particle-in-cell (PIC) simulations, we show that a plasma with a bi-peak density profile can be produced from a thin foil on the effects of a picosecond prepulse, and it can then lead to distinctive modulations in the ion phase space (phase locked double rings) when the main pulse interacts with the target. These fascinating ion dynamics are mainly due to the trapping effect from the ponderomotive potential well of a formed moving standing wave (i.e. the interference between the incoming pulse and the pulse reflected by a slowly moving surface) at nodes, quite different from the standard RPA process. A theoretical model is derived to explain the underlying mechanism, and good agreements have been achieved with PIC simulations.

Phase locked multiple rings in the radiation pressure ion acceleration process

DOE PAGES

Wan, Y.; Hua, J. F.; Pai, C. -H.; ...

2018-03-05

Laser contrast plays a crucial role for obtaining high quality ion beams in the radiation pressure ion acceleration (RPA) process. Through one- and two-dimensional particle-in-cell (PIC) simulations, we show that a plasma with a bi-peak density profile can be produced from a thin foil on the effects of a picosecond prepulse, and it can then lead to distinctive modulations in the ion phase space (phase locked double rings) when the main pulse interacts with the target. These fascinating ion dynamics are mainly due to the trapping effect from the ponderomotive potential well of a formed moving standing wave (i.e. themore » interference between the incoming pulse and the pulse reflected by a slowly moving surface) at nodes, quite different from the standard RPA process. Here, a theoretical model is derived to explain the underlying mechanism, and good agreements have been achieved with PIC simulations.« less

Phase locked multiple rings in the radiation pressure ion acceleration process

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

Wan, Y.; Hua, J. F.; Pai, C. -H.

Laser contrast plays a crucial role for obtaining high quality ion beams in the radiation pressure ion acceleration (RPA) process. Through one- and two-dimensional particle-in-cell (PIC) simulations, we show that a plasma with a bi-peak density profile can be produced from a thin foil on the effects of a picosecond prepulse, and it can then lead to distinctive modulations in the ion phase space (phase locked double rings) when the main pulse interacts with the target. These fascinating ion dynamics are mainly due to the trapping effect from the ponderomotive potential well of a formed moving standing wave (i.e. themore » interference between the incoming pulse and the pulse reflected by a slowly moving surface) at nodes, quite different from the standard RPA process. Here, a theoretical model is derived to explain the underlying mechanism, and good agreements have been achieved with PIC simulations.« less

The evidence for clumpy accretion in the Herbig Ae star HR 5999

NASA Technical Reports Server (NTRS)

Perez, M. R.; Grady, C. A.; The, P. S.

1993-01-01

Analysis of IUE high- and low-dispersion spectra of the young Herbig Ae star HR 5999 (HD 144668) covering 1978-1992 revealed dramatic changes in the Mg II h and k (2795.5, 2802.7 A) emission profiles, changes in the column density and distribution in radial velocity of accreting gas, and flux in the Ly(alpha), O I, and C IV emission lines, which are correlated with the UV excess luminosity. Variability in the spectral type inferred from the UV spectral energy distribution, ranging from A5 IV-III in high state to A7 III in the low state, was also observed. The trend of earlier inferred spectral type with decreasing wavelength and with increasing UV continuum flux has previously been noted as a signature of accretion disks in lower mass pre-main sequence stars (PMS) and in systems undergoing FU Orionis-type outbursts. Our data represent the first detection of similar phenomena in an intermediate mass (M greater than or equal to 2 solar mass) PMS star. Recent IUE spectra show gas accreting toward the star with velocities as high as plus 300 km/s, much as is seen toward beta Pic, and suggest that we also view this system through the debris disk. The absence of UV lines with the rotational broadening expected given the optical data (A7 IV, V sini=180 plus or minus 20 km/s for this system) also suggests that most of the UV light originates in the disk, even in the low continuum state. The dramatic variability in the column density of accreting gas, is consistent with clumpy accretion, such as has been observed toward beta Pic, is a hallmark of accretion onto young stars, and is not restricted to the clearing phase, since detectable amounts of accretion are present for stars with 0.5 Myr less than t(sub age) less than 2.8 Myr. The implications for models of beta Pic and similar systems are briefly discussed.

Freeing data through The Polar Information Commons

NASA Astrophysics Data System (ADS)

de Bruin, Taco; Chen, Robert; Parsons, Mark; Carlson, David

2010-05-01

The polar regions are changing rapidly with dramatic global effect. Wise management of resources, improved decision support, and effective international cooperation on resource and geopolitical issues require deeper understanding and better prediction of these changes. Unfortunately, polar data and information remain scattered, scarce, and sporadic. Inspired by the Antarctic Treaty of 1959 that established the Antarctic as a global commons to be used only for peaceful purposes and scientific research, we assert that data and information about the polar regions are themselves "public goods" that should be shared ethically and with minimal constraint. We therefore envision the Polar Information Commons (PIC) as an open, virtual repository for vital scientific data and information that would provide a shared, community-based cyber-infrastructure fostering innovation, improving scientific efficiency, and encouraging participation in polar research, education, planning, and management. The PIC will build on the legacy of the International Polar Year (IPY), providing a long-term framework for access to and preservation of both existing and future data and information about the polar regions. Rapid change demands rapid data access. The PIC system will enable scientists to quickly expose their data to the world and share them through open protocols on the Internet. A PIC digital label will alert users and data centers to new polar data and ensure that usage rights are clear. The PIC will utilize the Science Commons Protocol for Implementing Open Access Data, which promotes open data access through the public domain coupled with community norms of practice to ensure use of data in a fair and equitable manner. A set of PIC norms is currently being developed in consultation with key polar data organizations and other stakeholders. We welcome inputs from the broad science community as we further develop and refine the PIC approach and move ahead with implementation.

Freeing data through The Polar Information Commons

NASA Astrophysics Data System (ADS)

de Bruin, T.; Chen, R. S.; Parsons, M. A.; Carlson, D. J.

2009-12-01

The polar regions are changing rapidly with dramatic global effect. Wise management of resources, improved decision support, and effective international cooperation on resource and geopolitical issues require deeper understanding and better prediction of these changes. Unfortunately, polar data and information remain scattered, scarce, and sporadic. Inspired by the Antarctic Treaty of 1959 that established the Antarctic as a global commons to be used only for peaceful purposes and scientific research, we assert that data and information about the polar regions are themselves “public goods” that should be shared ethically and with minimal constraint. We therefore envision the Polar Information Commons (PIC) as an open, virtual repository for vital scientific data and information that would provide a shared, community-based cyber-infrastructure fostering innovation, improving scientific efficiency, and encouraging participation in polar research, education, planning, and management. The PIC will build on the legacy of the International Polar Year (IPY), providing a long-term framework for access to and preservation of both existing and future data and information about the polar regions. Rapid change demands rapid data access. The PIC system will enable scientists to quickly expose their data to the world and share them through open protocols on the Internet. A PIC digital label will alert users and data centers to new polar data and ensure that usage rights are clear. The PIC will utilize the Science Commons Protocol for Implementing Open Access Data, which promotes open data access through the public domain coupled with community norms of practice to ensure use of data in a fair and equitable manner. A set of PIC norms is currently being developed in consultation with key polar data organizations and other stakeholders. We welcome inputs from the broad science community as we further develop and refine the PIC approach and move ahead with implementation.

OSIRIS - an object-oriented parallel 3D PIC code for modeling laser and particle beam-plasma interaction

NASA Astrophysics Data System (ADS)

Hemker, Roy

1999-11-01

The advances in computational speed make it now possible to do full 3D PIC simulations of laser plasma and beam plasma interactions, but at the same time the increased complexity of these problems makes it necessary to apply modern approaches like object oriented programming to the development of simulation codes. We report here on our progress in developing an object oriented parallel 3D PIC code using Fortran 90. In its current state the code contains algorithms for 1D, 2D, and 3D simulations in cartesian coordinates and for 2D cylindrically-symmetric geometry. For all of these algorithms the code allows for a moving simulation window and arbitrary domain decomposition for any number of dimensions. Recent 3D simulation results on the propagation of intense laser and electron beams through plasmas will be presented.

High-Speed Particle-in-Cell Simulation Parallelized with Graphic Processing Units for Low Temperature Plasmas for Material Processing

NASA Astrophysics Data System (ADS)

Hur, Min Young; Verboncoeur, John; Lee, Hae June

2014-10-01

Particle-in-cell (PIC) simulations have high fidelity in the plasma device requiring transient kinetic modeling compared with fluid simulations. It uses less approximation on the plasma kinetics but requires many particles and grids to observe the semantic results. It means that the simulation spends lots of simulation time in proportion to the number of particles. Therefore, PIC simulation needs high performance computing. In this research, a graphic processing unit (GPU) is adopted for high performance computing of PIC simulation for low temperature discharge plasmas. GPUs have many-core processors and high memory bandwidth compared with a central processing unit (CPU). NVIDIA GeForce GPUs were used for the test with hundreds of cores which show cost-effective performance. PIC code algorithm is divided into two modules which are a field solver and a particle mover. The particle mover module is divided into four routines which are named move, boundary, Monte Carlo collision (MCC), and deposit. Overall, the GPU code solves particle motions as well as electrostatic potential in two-dimensional geometry almost 30 times faster than a single CPU code. This work was supported by the Korea Institute of Science Technology Information.

The gaseous component of the disk around Beta Pictoris

NASA Technical Reports Server (NTRS)

Hobbs, L. M.; Vidal-Madjar, A.; Ferlet, R.; Albert, C. E.; Gry, C.

1985-01-01

Optical spectra of alpha Lyr, alpha PsA, and beta Pic have been obtained at a velocity resolution of 3 km/s. No circumstellar absorption lines of Ca II or Na I are detected toward alpha Lyr or alpha PsA at sensitive limits. In the favorable case of beta Pic, where the circumstellar disk imaged by Smith and Terrile (1984) is seen nearly edge-on, a strong, narrow, circumstellar Ca II K absorption line previously reported by Slettebak (1982) and weaker, still narrower circumstellar Na I D lines are detected. Negative results of high sensitivity also are obtained for the Ca I 4226 A and CH(+) 4232 A lines, along with upper limits on the Zn II 2026, 2062 A doublet from archival IUE spectra. Under assumptions which agree with other well-established observations of the gaseous abundances of calcium and zinc, the total gaseous column density of hydrogen along a radius of the circumstellar disk is between 10 to the 18th and 4 x 10 to the 20th/sq cm. Within the boundaries of the dust disk detected by Smith and Terrile (1984) the total gaseous mass then is less than about 2, or less than 1 percent of the mass of the planetary system. A simplified model of the density distribution in the gaseous disk yields a characteristic total density n(H) of about 100,000/cu cm, which exceeds that of all interplanetary gas at earth's position by a factor of about 10,000.

Photometric study of fine structure of a sunspot penumbra (in French)

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

Muller, R.

1973-10-01

The microphotometric analysis of the fime structure of a sunspot penumbra, photographed in white hight with the 38 cm refractor of the Pic du Midi Observatory with a resolution very close to 0.3'', allows to give from it, at lambda 5280, the following picture: the penumbra appears to consist of bright grains, lined up in the form of filaments, with am average brightness I/sub beta //I = 0.95 of average width 0.36''(270 km) and which cover 43% of its surface, show-ing up a dark background of brightness I/sub beta //I = 0.6 nearly uniform. (auth)

Urinary coagulation-fibrinolysis, kallirein-kinin systems and kininase in cases of preclampsia.

PubMed

Mutoh, S; Kobayashi, M; Hirata, J; Itoh, N; Maki, M; Komatsu, Y; Yoshida, A; Sasa, H; Kuroda, K; Kikuchi, Y

1992-01-01

Urinary kallikrein and kallikrein activity significantly decreased in cases of preeclampsia (u-kall./CRE.index 42.39 +/- 9.66 ng/mg, u-kall. act./CRE.index 0.26 +/- 0.06 ng/min/mg), and urinary kininase II and kininase activity significantly increased (u-kininase/CRE.index 10.91 +/- 1.26 x 10(-3) IU/min/mg, u-kininase act./CRE.index 506.37 +/- 178.45 pg/min/mg) when compared with those of normal gravidas from 28 weeks to 42 weeks of gestation (u-kall./CRE.index 189.31 +/- 14.17 ng/mg, u-kall. act./CRE index 1.08 +/- 0.10 ng/min/mg, u-kininase/CRE.index 6.24 +/- 0.31 x 10(-3) IU/min/mg, u-kininase act./CRE.index 15.64 +/- 0.10 pg/min/mg). Urinary FPA, B beta 5-42, alpha 2-PI, and alpha 2PI-plasmin-complex (PIC) significantly increased in preeclampsia (u-FPA/CRE.index 23.59 +/- 8.47 ng/mg, u-B beta/CRE.index 105.26 +/- 29.30 ng/mg, u-alpha 2PI/CRE.index 121.53 +/- 43.57 ng/mg, u-PIC/CRE index 278.39 +/- 60.50 ng/mg) when compared with those of normal control group (u-FPA/CRE.index 0.92 +/- 0.04 ng/mg, u-B beta/CRE.index 12.15 +/- 0.44 ng/mg, u-alpha 2PI/CRE.index 4.18 +/- 0.33 ng/mg, u-PIC/CRE.index 5.98 +/- 1.15 ng/mg). Urinary urokinase markedly increased and urinary D-dimer was detected in severe cases of preeclampsia (u-UK/CRE.index 58.20 +/- 43.69 ng/mg, u-D-dimer 54.76 +/- 9.89 ng/ml) when compared with those of normal control group. These findings suggest that deficiency in urinary kinin excretion may induce hypertension in addition to the changes of urinary coagulation-fibrinolysis system that represents the occurrence of either the endothelial cell injury in the glomerulus or the renal tulbular damage in mild cases of preeclampsia, eventually resulting in the intra-renal vascular coagulation.

Response of plasma facing components in Tokamaks due to intense energy deposition using Particle-In-Cell (PIC) methods

NASA Astrophysics Data System (ADS)

Genco, Filippo

Damage to plasma-facing components (PFC) due to various plasma instabilities is still a major concern for the successful development of fusion energy and represents a significant research obstacle in the community. It is of great importance to fully understand the behavior and lifetime expectancy of PFC under both low energy cycles during normal events and highly energetic events as disruptions, Edge-Localized Modes (ELM), Vertical Displacement Events (VDE), and Run-away electron (RE). The consequences of these high energetic dumps with energy fluxes ranging from 10 MJ/m2 up to 200 MJ/m 2 applied in very short periods (0.1 to 5 ms) can be catastrophic both for safety and economic reasons. Those phenomena can cause a) large temperature increase in the target material b) consequent melting, evaporation and erosion losses due to the extremely high heat fluxes c) possible structural damage and permanent degradation of the entire bulk material with probable burnout of the coolant tubes; d) plasma contamination, transport of target material into the chamber far from where it was originally picked. The modeling of off-normal events such as Disruptions and ELMs requires the simultaneous solution of three main problems along time: a) the heat transfer in the plasma facing component b) the interaction of the produced vapor from the surface with the incoming plasma particles c) the transport of the radiation produced in the vapor-plasma cloud. In addition the moving boundaries problem has to be considered and solved at the material surface. Considering the carbon divertor as target, the moving boundaries are two since for the given conditions, carbon doesn't melt: the plasma front and the moving eroded material surface. The current solution methods for this problem use finite differences and moving coordinates system based on the Crank-Nicholson method and Alternating Directions Implicit Method (ADI). Currently Particle-In-Cell (PIC) methods are widely used for solving complex dynamics problems involving distorted plasma hydrodynamic problems and plasma physics. The PIC method solves the hydrodynamic equations solving all field equations tracking at the same time "sample particles" or pseudo-particles (representative of the much more numerous real ones) as the move under the influence of diffusion or magnetic force. The superior behavior of the PIC techniques over the more classical Lagrangian finite difference methods stands in the fact that detailed information about the particles are available at all times as well as mass and momentum transport values are constantly provided. This allows with a relative small number of particles to well describe the behavior of plasma even in presence of highly distorted flows without losing accuracy. The radiation transport equation is solved at each time step calculating for each cell the opacity and emissivity coefficients. Photon radiation continuum and line fluxes are also calculated per the entire domain and provide useful information for the entire energetic calculation of the system which in the end provides the total values of erosion and lifetime of the target material. In this thesis, a new code named HEIGHTS-PIC code has been created and modified using a new approach of the PIC technique to solve the three physics problems involved integrating each of them as a continuum providing insight on the plasma behavior, evolution along time and physical understanding of the very complex phenomena taking place. The results produced with the models are compared with the well-known and benchmarked HEIGHTS package and also with existing experimental results especially produced in Russia at the TRINITI facility. Comparisons with LASER experiments are also discussed.

An electrostatic Particle-In-Cell code on multi-block structured meshes

NASA Astrophysics Data System (ADS)

Meierbachtol, Collin S.; Svyatskiy, Daniil; Delzanno, Gian Luca; Vernon, Louis J.; Moulton, J. David

2017-12-01

We present an electrostatic Particle-In-Cell (PIC) code on multi-block, locally structured, curvilinear meshes called Curvilinear PIC (CPIC). Multi-block meshes are essential to capture complex geometries accurately and with good mesh quality, something that would not be possible with single-block structured meshes that are often used in PIC and for which CPIC was initially developed. Despite the structured nature of the individual blocks, multi-block meshes resemble unstructured meshes in a global sense and introduce several new challenges, such as the presence of discontinuities in the mesh properties and coordinate orientation changes across adjacent blocks, and polyjunction points where an arbitrary number of blocks meet. In CPIC, these challenges have been met by an approach that features: (1) a curvilinear formulation of the PIC method: each mesh block is mapped from the physical space, where the mesh is curvilinear and arbitrarily distorted, to the logical space, where the mesh is uniform and Cartesian on the unit cube; (2) a mimetic discretization of Poisson's equation suitable for multi-block meshes; and (3) a hybrid (logical-space position/physical-space velocity), asynchronous particle mover that mitigates the performance degradation created by the necessity to track particles as they move across blocks. The numerical accuracy of CPIC was verified using two standard plasma-material interaction tests, which demonstrate good agreement with the corresponding analytic solutions. Compared to PIC codes on unstructured meshes, which have also been used for their flexibility in handling complex geometries but whose performance suffers from issues associated with data locality and indirect data access patterns, PIC codes on multi-block structured meshes may offer the best compromise for capturing complex geometries while also maintaining solution accuracy and computational efficiency.

An electrostatic Particle-In-Cell code on multi-block structured meshes

DOE PAGES

Meierbachtol, Collin S.; Svyatskiy, Daniil; Delzanno, Gian Luca; ...

2017-09-14

We present an electrostatic Particle-In-Cell (PIC) code on multi-block, locally structured, curvilinear meshes called Curvilinear PIC (CPIC). Multi-block meshes are essential to capture complex geometries accurately and with good mesh quality, something that would not be possible with single-block structured meshes that are often used in PIC and for which CPIC was initially developed. In spite of the structured nature of the individual blocks, multi-block meshes resemble unstructured meshes in a global sense and introduce several new challenges, such as the presence of discontinuities in the mesh properties and coordinate orientation changes across adjacent blocks, and polyjunction points where anmore » arbitrary number of blocks meet. In CPIC, these challenges have been met by an approach that features: (1) a curvilinear formulation of the PIC method: each mesh block is mapped from the physical space, where the mesh is curvilinear and arbitrarily distorted, to the logical space, where the mesh is uniform and Cartesian on the unit cube; (2) a mimetic discretization of Poisson's equation suitable for multi-block meshes; and (3) a hybrid (logical-space position/physical-space velocity), asynchronous particle mover that mitigates the performance degradation created by the necessity to track particles as they move across blocks. The numerical accuracy of CPIC was verified using two standard plasma–material interaction tests, which demonstrate good agreement with the corresponding analytic solutions. And compared to PIC codes on unstructured meshes, which have also been used for their flexibility in handling complex geometries but whose performance suffers from issues associated with data locality and indirect data access patterns, PIC codes on multi-block structured meshes may offer the best compromise for capturing complex geometries while also maintaining solution accuracy and computational efficiency.« less

An electrostatic Particle-In-Cell code on multi-block structured meshes

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

Meierbachtol, Collin S.; Svyatskiy, Daniil; Delzanno, Gian Luca

We present an electrostatic Particle-In-Cell (PIC) code on multi-block, locally structured, curvilinear meshes called Curvilinear PIC (CPIC). Multi-block meshes are essential to capture complex geometries accurately and with good mesh quality, something that would not be possible with single-block structured meshes that are often used in PIC and for which CPIC was initially developed. In spite of the structured nature of the individual blocks, multi-block meshes resemble unstructured meshes in a global sense and introduce several new challenges, such as the presence of discontinuities in the mesh properties and coordinate orientation changes across adjacent blocks, and polyjunction points where anmore » arbitrary number of blocks meet. In CPIC, these challenges have been met by an approach that features: (1) a curvilinear formulation of the PIC method: each mesh block is mapped from the physical space, where the mesh is curvilinear and arbitrarily distorted, to the logical space, where the mesh is uniform and Cartesian on the unit cube; (2) a mimetic discretization of Poisson's equation suitable for multi-block meshes; and (3) a hybrid (logical-space position/physical-space velocity), asynchronous particle mover that mitigates the performance degradation created by the necessity to track particles as they move across blocks. The numerical accuracy of CPIC was verified using two standard plasma–material interaction tests, which demonstrate good agreement with the corresponding analytic solutions. And compared to PIC codes on unstructured meshes, which have also been used for their flexibility in handling complex geometries but whose performance suffers from issues associated with data locality and indirect data access patterns, PIC codes on multi-block structured meshes may offer the best compromise for capturing complex geometries while also maintaining solution accuracy and computational efficiency.« less

Formation of electrostatic structures by wakefield acceleration in ultrarelativistic plasma flows: Electron acceleration to cosmic ray energies

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

Dieckmann, M.E.; Shukla, P.K.; Eliasson, B.

2006-06-15

The ever increasing performance of supercomputers is now enabling kinetic simulations of extreme astrophysical and laser produced plasmas. Three-dimensional particle-in-cell (PIC) simulations of relativistic shocks have revealed highly filamented spatial structures and their ability to accelerate particles to ultrarelativistic speeds. However, these PIC simulations have not yet revealed mechanisms that could produce particles with tera-electron volt energies and beyond. In this work, PIC simulations in one dimension (1D) of the foreshock region of an internal shock in a gamma ray burst are performed to address this issue. The large spatiotemporal range accessible to a 1D simulation enables the self-consistent evolutionmore » of proton phase space structures that can accelerate particles to giga-electron volt energies in the jet frame of reference, and to tens of tera-electron volt in the Earth's frame of reference. One potential source of ultrahigh energy cosmic rays may thus be the thermalization of relativistically moving plasma.« less

Vascular cell adhesion molecule-1 (VCAM-1) gene transcription and expression are regulated through an antioxidant-sensitive mechanism in human vascular endothelial cells.

PubMed Central

Marui, N; Offermann, M K; Swerlick, R; Kunsch, C; Rosen, C A; Ahmad, M; Alexander, R W; Medford, R M

1993-01-01

Oxidative stress and expression of the vascular cell adhesion molecule-1 (VCAM-1) on vascular endothelial cells are early features in the pathogenesis of atherosclerosis and other inflammatory diseases. Regulation of VCAM-1 gene expression may be coupled to oxidative stress through specific reduction-oxidation (redox) sensitive transcriptional or posttranscriptional regulatory factors. In cultured human umbilical vein endothelial (HUVE) cells, the cytokine interleukin 1 beta (IL-1 beta) activated VCAM-1 gene expression through a mechanism that was repressed approximately 90% by the antioxidants pyrrolidine dithiocarbamate (PDTC) and N-acetylcysteine (NAC). Furthermore, PDTC selectively inhibited the induction of VCAM-1, but not intercellular adhesion molecule-1 (ICAM-1), mRNA and protein accumulation by the cytokine tumor necrosis factor-alpha (TNF alpha) as well as the noncytokines bacterial endotoxin lipopolysaccharide (LPS) and double-stranded RNA, poly(I:C) (PIC). PDTC also markedly attenuated TNF alpha induction of VCAM-1-mediated cellular adhesion. In a distinct pattern, PDTC partially inhibited E-selectin gene expression in response to TNF alpha but not to LPS, IL-1 beta, or PIC. TNF alpha and LPS-mediated transcriptional activation of the human VCAM-1 promoter through NF-kappa B-like DNA enhancer elements and associated NF-kappa B-like DNA binding proteins was inhibited by PDTC. These studies suggest a molecular linkage between an antioxidant sensitive transcriptional regulatory mechanism and VCAM-1 gene expression that expands on the notion of oxidative stress as an important regulatory signal in the pathogenesis of atherosclerosis. Images PMID:7691889

Hybrid-PIC simulation of sputtering product distribution in a Hall thruster

NASA Astrophysics Data System (ADS)

Cao, Xifeng; Hang, Guanrong; Liu, Hui; Meng, Yingchao; Luo, Xiaoming; Yu, Daren

2017-10-01

Hall thrusters have been widely used in orbit correction and the station-keeping of geostationary satellites due to their high specific impulse, long life, and high reliability. During the operating life of a Hall thruster, high-energy ions will bombard the discharge channel and cause serious erosion. As time passes, this sputtering process will change the macroscopic surface morphology of the discharge channel, especially near the exit, thus affecting the performance of the thruster. Therefore, it is necessary to carry out research on the motion of the sputtering products and erosion process of the discharge wall. To better understand the moving characteristics of sputtering products, based on the hybrid particle-in-cell (PIC) numerical method, this paper simulates the different erosion states of the thruster discharge channel in different moments and analyzes the moving process of different particles, such as B atoms and B+ ions. In this paper, the main conclusion is that B atoms are mainly produced on both sides of the channel exit, and B+ ions are mainly produced in the middle of the channel exit. The ionization rate of B atoms is approximately 1%.

Estimates of the location of L-type Ca2+ channels in motoneurons of different sizes: a computational study.

PubMed

Grande, Giovanbattista; Bui, Tuan V; Rose, P Ken

2007-06-01

In the presence of monoamines, L-type Ca(2+) channels on the dendrites of motoneurons contribute to persistent inward currents (PICs) that can amplify synaptic inputs two- to sixfold. However, the exact location of the L-type Ca(2+) channels is controversial, and the importance of the location as a means of regulating the input-output properties of motoneurons is unknown. In this study, we used a computational strategy developed previously to estimate the dendritic location of the L-type Ca(2+) channels and test the hypothesis that the location of L-type Ca(2+) channels varies as a function of motoneuron size. Compartmental models were constructed based on dendritic trees of five motoneurons that ranged in size from small to large. These models were constrained by known differences in PIC activation reported for low- and high-conductance motoneurons and the relationship between somatic PIC threshold and the presence or absence of tonic excitatory or inhibitory synaptic activity. Our simulations suggest that L-type Ca(2+) channels are concentrated in hotspots whose distance from the soma increases with the size of the dendritic tree. Moving the hotspots away from these sites (e.g., using the hotspot locations from large motoneurons on intermediate-sized motoneurons) fails to replicate the shifts in PIC threshold that occur experimentally during tonic excitatory or inhibitory synaptic activity. In models equipped with a size-dependent distribution of L-type Ca(2+) channels, the amplification of synaptic current by PICs depends on motoneuron size and the location of the synaptic input on the dendritic tree.

The Beta Pictoris circumstellar disk. XV - Highly ionized species near Beta Pictoris

NASA Technical Reports Server (NTRS)

Deleuil, M.; Gry, C.; Lagrange-Henri, A.-M.; Vidal-Madjar, A.; Beust, H.; Ferlet, R.; Moos, H. W.; Livengood, T. A.; Ziskin, D.; Feldman, P. D.

1993-01-01

Temporal variations of the Fe II, Mg II, and Al III circumstellar lines towards Beta Pictoris have been detected and monitored since 1985. However, the unusual presence of Al III ions is still puzzling, since the UV stellar flux from an A5V star such as Beta Pic is insufficient to produce such an ion. In order to better define the origin of such a phenomenon, new observations have been carried out to detect faint signatures of other highly ionized species in the short UV wavelength range, where the stellar continuum flux is low. These observations reveal variations not only near the C IV doublet lines, but also in C I and Al II lines, two weakly ionized species, not clearly detectable until now. In the framework of an infalling body scenario, highly ionized species would be created in the tail, far from the comet head, by collisions with ambient gas surrounding the star, or a weak stellar wind. Spectral changes have also been detected near a CO molecular band location, which, if confirmed, would provide the first molecular signature around Beta Pictoris.

The SEEDS Direct Imaging Survey for Planets and Scattered Dust Emission in Debris Disk Systems

NASA Technical Reports Server (NTRS)

Janson, Markus; Brandt, Timothy; Moro-Martin, Amaya; Usuda, Tomonori; Thalmann, Christian; Carson, Joseph C.; Goto, Miwa; Currie, Thayne; McElwain, M. W.; Itoh, Yoichi;

The Automation and Exoplanet Orbital Characterization from the Gemini Planet Imager Exoplanet Survey

NASA Astrophysics Data System (ADS)

Jinfei Wang, Jason; Graham, James; Perrin, Marshall; Pueyo, Laurent; Savransky, Dmitry; Kalas, Paul; arriaga, Pauline; Chilcote, Jeffrey K.; De Rosa, Robert J.; Ruffio, Jean-Baptiste; Sivaramakrishnan, Anand; Gemini Planet Imager Exoplanet Survey Collaboration

2018-01-01

The Gemini Planet Imager (GPI) Exoplanet Survey (GPIES) is a multi-year 600-star survey to discover and characterize young Jovian exoplanets and their planet forming environments. For large surveys like GPIES, it is critical to have a uniform dataset processed with the latest techniques and calibrations. I will describe the GPI Data Cruncher, an automated data processing framework that is able to generate fully reduced data minutes after the data are taken and can also reprocess the entire campaign in a single day on a supercomputer. The Data Cruncher integrates into a larger automated data processing infrastructure which syncs, logs, and displays the data. I will discuss the benefits of the GPIES data infrastructure, including optimizing observing strategies, finding planets, characterizing instrument performance, and constraining giant planet occurrence. I will also discuss my work in characterizing the exoplanets we have imaged in GPIES through monitoring their orbits. Using advanced data processing algorithms and GPI's precise astrometric calibration, I will show that GPI can achieve one milliarcsecond astrometry on the extensively-studied planet Beta Pic b. With GPI, we can confidently rule out a possible transit of Beta Pic b, but have precise timings on a Hill sphere transit, and I will discuss efforts to search for transiting circumplanetary material this year. I will also discuss the orbital monitoring of other exoplanets as part of GPIES.

Molecular Gas Clumps from the Destruction of Icy Bodies in the beta Pictoris Debris Disk

NASA Technical Reports Server (NTRS)

Dent, W. R. F.; Wyatt, M. C.; Roberge, A.; Augereau, J. -C.; Casassus, S.; Corder, S.; Greaves, J. S.; DeGregorio-Monsalvo, I.; Hales, A.; Jackson, A. P.;

Three-dimensional kinetic simulations of whistler turbulence in solar wind on parallel supercomputers

NASA Astrophysics Data System (ADS)

Chang, Ouliang

The objective of this dissertation is to study the physics of whistler turbulence evolution and its role in energy transport and dissipation in the solar wind plasmas through computational and theoretical investigations. This dissertation presents the first fully three-dimensional (3D) particle-in-cell (PIC) simulations of whistler turbulence forward cascade in a homogeneous, collisionless plasma with a uniform background magnetic field B o, and the first 3D PIC simulation of whistler turbulence with both forward and inverse cascades. Such computationally demanding research is made possible through the use of massively parallel, high performance electromagnetic PIC simulations on state-of-the-art supercomputers. Simulations are carried out to study characteristic properties of whistler turbulence under variable solar wind fluctuation amplitude (epsilon e) and electron beta (betae), relative contributions to energy dissipation and electron heating in whistler turbulence from the quasilinear scenario and the intermittency scenario, and whistler turbulence preferential cascading direction and wavevector anisotropy. The 3D simulations of whistler turbulence exhibit a forward cascade of fluctuations into broadband, anisotropic, turbulent spectrum at shorter wavelengths with wavevectors preferentially quasi-perpendicular to B o. The overall electron heating yields T ∥ > T⊥ for all epsilone and betae values, indicating the primary linear wave-particle interaction is Landau damping. But linear wave-particle interactions play a minor role in shaping the wavevector spectrum, whereas nonlinear wave-wave interactions are overall stronger and faster processes, and ultimately determine the wavevector anisotropy. Simulated magnetic energy spectra as function of wavenumber show a spectral break to steeper slopes, which scales as k⊥lambda e ≃ 1 independent of betae values, where lambdae is electron inertial length, qualitatively similar to solar wind observations. Specific spectral indices from simulated wavevector energy spectra do not match the frequency spectral indices from observations due to the inapplicability of Taylor's hypothesis. In contrast, the direct comparison of simulated frequency energy spectra and solar wind observations shows a closer similarity. Electron density fluctuations power spectra also exhibit a close similarity to solar wind observations and MHD predications, both qualitatively and quantitatively. Linear damping represents an intermediate fraction of the total dissipation of whistler turbulence over a wide range of betae and epsilone. The relative importance of linear damping by comparison to nonlinear dissipation increases with increasing beta e but decreases with increasing epsilone. Correlation coefficient calculations imply that the nonlinear dissipation processes in our simulation are primarily associated with dissipation in regions of intermittent current sheet structures. The simulation results suggest that whistler fluctuations could be the substantial constituent of solar wind turbulence at higher frequencies and short wavelengths, and support the magnetosonic-whistler interpretation of the quasilinear scenario. An even larger scale 3D whistler turbulence simulation exhibits both a forward cascade to shorter wavelengths with wavevectors preferentially k⊥ > k∥, and an inverse cascade to longer wavelengths with wavevectors k ≳ k⊥. The inverse cascade process is primarily driven by the nonlinear wave-wave interaction. It is shown that the energy inverse cascade rate is similar to the energy forward cascade rate at early times although the overall energy in the two cascades is very different. The presence of inverse cascade process does not affect qualitative conclusions established from the whistler turbulence forward cascade simulations.

A 5 Micron of beta Pictoris B at a Sub-Jupiter Projected Separation: Evidence for a Misalignment Between the Planet and the Inner, Warped Disk

NASA Technical Reports Server (NTRS)

Currie, Thayne; Thalmann, Christian; Matsumura, Soko; Madhusudhan, Nikku; Burrows, Adam; Kuchner, Marc

2011-01-01

We present and analyze a new M' detection of the young exoplanet Beta Pictoris b from 2008 VLT/NaCo data at a separation of approx. = 4 AU and a high signal-to-noise rereduction of L' data taken in December 2Q09. Based on our orbital analysis, the planet's orbit is viewed almost perfectly edge-on (i approx. 89 degrees) and has a Saturn-like semimajor axis of 9.50AU(+3.93 AU)/-(1.7AU) . Intriguingly, the planet's orbit is aligned with the major axis of the outer disk (Omega approx.31 degrees) but probably misaligned with the warp/inclined disk at 80 AU often cited as a signpost for the planet's existence. Our results motivate new studies to clarify how Beta Pic b sculpts debris disk structures and whether a second planet is required to explain the warp/inclined disk

Massive collisions in debris disks: possible application to the beta Pic disc

NASA Astrophysics Data System (ADS)

Kral, Q.; Thébault, P.; Augereau, J.-C.; Boccaletti, A.; Charnoz, S.

2014-09-01

The new LIDT-DD code has been used to study massive collisions in debris discs. This new hybrid model is a fully self-consistent code coupling dynamics and collisions to study debris discs (Kral et al. 2013). It models the full complexity of debris discs' physics such as high velocity collisions, radiation-pressure affected orbits, wide range of grains' dynamical behaviour, etc. LIDT-DD can be used on many possible applications. Our first test case concerns the violent breakup of a massive planetesimal such as the ones happening during the late stages of planetary formation or with the biggest bodies in debris belts. We investigate the duration, magnitude and spatial structure of the signature left by such a violent event, as well as its observational detectability. We find that the breakup of a Ceres-sized body creates an asymmetric dust disc that is homogenized, by the coupled action of collisions and dynamics. The luminosity excess in the breakup's aftermath should be detectable by mid-IR photometry, from a 30 pc distance. As for the asymmetric structures, we derive synthetic images for the SPHERE/VLT and MIRI/JWST instruments, showing that they should be clearly visible and resolved from a 10 pc distance. We explain the observational signature of such impacts and give scaling laws to extrapolate our results to different configurations. These first results confirm that our code can be used to study the massive collision scenario to explain some asymmetries in the Beta-Pic disc.

Inhibition of NF-κB activity in the hypothalamic paraventricular nucleus attenuates hypertension and cardiac hypertrophy by modulating cytokines and attenuating oxidative stress

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

Yu, Xiao-Jing; Zhang, Dong-Mei; Jia, Lin-Lin

We hypothesized that chronic inhibition of NF-κB activity in the hypothalamic paraventricular nucleus (PVN) delays the progression of hypertension and attenuates cardiac hypertrophy by up-regulating anti-inflammatory cytokines, reducing pro-inflammatory cytokines (PICs), attenuating nuclear factor-κB (NF-κB) p65 and NAD(P)H oxidase in the PVN of young spontaneously hypertensive rats (SHR). Young normotensive Wistar–Kyoto (WKY) and SHR rats received bilateral PVN infusions with NF–κB inhibitor pyrrolidine dithiocarbamate (PDTC) or vehicle for 4 weeks. SHR rats had higher mean arterial pressure and cardiac hypertrophy as indicated by increased whole heart weight/body weight ratio, whole heart weight/tibia length ratio, left ventricular weight/tibia length ratio, cardiomyocytemore » diameters of the left cardiac ventricle, and mRNA expressions of cardiac atrial natriuretic peptide (ANP) and beta-myosin heavy chain (β-MHC). These SHR rats had higher PVN levels of proinflammatory cytokines (PICs), reactive oxygen species (ROS), the chemokine monocyte chemoattractant protein-1 (MCP-1), NAD(P)H oxidase activity, mRNA expression of NOX-2 and NOX-4, and lower PVN IL-10, and higher plasma levels of PICs and NE, and lower plasma IL-10. PVN infusion of NF-κB inhibitor PDTC attenuated all these changes. These findings suggest that NF-κB activation in the PVN increases sympathoexcitation and hypertensive response, which are associated with the increases of PICs and oxidative stress in the PVN; PVN inhibition of NF-κB activity attenuates PICs and oxidative stress in the PVN, thereby attenuates hypertension and cardiac hypertrophy. - Highlights: • Spontaneously hypertensive rats exhibit neurohormonal excitation in the PVN. • PVN inhibition of NF-κB attenuates hypertension-induced cardiac hypertrophy. • PVN inhibition of NF-κB attenuates hypertension-induced neurohormonal excitation. • PVN inhibition of NF-κB attenuates hypertension-induced imbalance of cytokines. • PVN inhibition of NF-κB attenuates PVN NF-κB p65 activity and oxidative stress.« less

Regulated expression of the rat recombinant P2X(3) receptor in stably transfected CHO-K1 tTA cells.

PubMed

Lachnit, W G; Oglesby, I B; Gever, J R; Gever, M; Huang, C; Li, X C; Jin, H; McGivern, J G; Ford, A P

2000-07-03

In this report, the regulatable expression by tetracycline of the rat recombinant P2X(3) receptor in stably transfected Chinese hamster ovary (CHO-K1) expressing the tetracycline-controlled transactivator (tTA) is described. cDNA encoding the rat P2X(3)-receptor was subcloned into pTRE (a tetracycline-repressible expression vector) which was used to transfect stably CHO-K1 tTA cells. Using whole cell patch clamp techniques, 100 microM ATP evoked inward currents of 2.9+/-1.6 nA in transfected cells grown in the absence of tetracycline (tet-). The P2X(3) receptor protein was detectable by immunoblot as early as 24 h and protein expression levels continued to increase as much as 192 h following activation of tTA by the removal of the antibiotic. Saturation binding isotherms using [35S]ATP gamma S yielded a pK(d) of 8.2+/-0.1 and a B(max) of 31.9+/-3.5 pmol/mg protein in tet- cell membranes and a pK(d) of 8.1+/-0.1 and a B(max) of 5.8+/-0.8 pmol/mg protein in tet+ cell membranes. The agonist ligands 2MeSATP and alpha beta MeATP displaced the binding of [35S]ATP gamma S in tet- cell membranes with very high affinity, yielding pIC(50) values of 9.4+/-0.2 and 7.5+/-0. 2, respectively. In tet+ cell membrane, displacement of [35S]ATP gamma S by 2MeSATP and alpha beta MeATP was of much lower affinity (pIC(50) values of 7.8 and 6.2, respectively). ATP, ADP and UTP showed similar displacement of [35S]ATP gamma S binding in tet- and tet+ cell membranes. In other experiments, cytosolic Ca(2+) was monitored using the fluorescent indicator, fluo-3. Increases in cytosolic Ca(2+) were elicited by 100 nM alpha beta MeATP in tet- cells while no increases in cytosolic Ca(2+) were detected below 100 microM alpha beta MeATP in either tet+ cells or untransfected cells. These calcium responses to alpha beta MeATP had a pEC(50) of 6.7 and were transient, returning to baseline within 120 s. Suramin produced concentration-dependent, parallel, dextral shifts of E/[A] curves to alpha beta MeATP yielding a pK(B) of 5.6. PPADS produced non-parallel, dextral shifts of E/[A] curves to alpha beta MeATP which were insurmountable. These results show for the first time, expression of a functional, homomeric recombinant rat P2X(3) receptor which is under regulated expression in a stably transfected mammalian cell line.

Submillimeter Imaging of Dust Around Main Sequence Stars

NASA Technical Reports Server (NTRS)

Jewitt, David

1998-01-01

This grant was to image circumstellar dust disks surrounding main-sequence stars. The delivery of the SCUBA detector we had planned to use for this work was delayed repeatedly, leading us to undertake a majority of the observations with the UKT14 submillimeter detector at the JCMT (James Clerk Maxwell Telescope) and optical imagers and a coronagraph at the University of Hawaii 2.2-m telescope. Major findings under this grant include: (1) We discovered 5 asymmetries in the beta Pictoris regenerated dust disk. The discovery of these asymmetries was a surprise, since smearing due to Keplerian shear should eliminate most such features on timescales of a few thousand years. One exception is the "wing tilt" asymmetry, which we interpret as due to the scattering phase function of dust disk particles. From the wing tilt and a model of the phase function, we find a disk plane inclination to the line of sight of < 5 degrees. Other asymmetries (e.g. the butterfly asymmetry) suggest a disk that has been recently disturbed. We searched for possible nearby perturbers but found no clear candidates. Low mass stars (M dwarfs) and brown dwarfs would have fallen beneath the sensitivity threshhold of our survey, however. (2) We calculated a set of disk models to assess the detectability of dust disks around stars as a function of (a) distance, (b) disk, inclination (c) dust optical depth/mass, and (d) imaging resolution. These models guided our observational strategy on Mauna Kea. (3) We performed a coronagraphic survey of approx. 100 main-sequence stars in search of additional examples of circumstellar disks. The best new candidate disk, around the 5 M(sun) star BD+31deg.643, is distinguished by its large extent (few x 10( exp 3) AU). This disk, if real, cannot be rotationally supported. We suggest that the dust particles are ejected from a smaller, unseen disk (Kuiper Belt?) by strong radiation pressure forces due to the high luminosity central star. (4) SCUBA images of circumstellar dust disks were obtained at 850 gm in 1997/8. These images show extended, asymmetric emission, but have a signal-to-noise ratio too low to permit disk mapping to large projected distances. Our images of beta Pic, in particular, are in agreement with those obtained by Holland et al., and appear to confirm the blob-structure reported first by these authors. We have not yet been able to confirm that the structure is intrinsic to the disk, since beta Pic is at -50 degree declination, and suitable observing opportunities from northern latitudes are comparatively rare (even at the +20 degree latitude of JCMT). It is possible, for instance, that the main 850 micro-m blob is merely a galaxy or other high-z source projected onto the beta Pic mid-plane.

Cool circumstellar matter around nearby main-sequence stars

NASA Technical Reports Server (NTRS)

Walker, H. J.; Wolstencroft, R. D.

1988-01-01

Stars are presented which have characteristics similar to Vega and other main-sequence stars with cool dust disks, based on the IRAS Point Source Catalog fluxes. The objects are selected to have a 60-micron/100-micron ratio similar to Vega, Beta Pic, Alpha PsA, and Epsilon Eri, and they are also required to show evidence of extension in the IRAS Working Survey Database. The fluxes are modeled using a blackbody energy distribution. The temperatures derived range from 50 to 650 K. The diameters of the dust disks observed by IRAS are estimated.

Studies of extra-solar Oort Clouds and the Kuiper disk

NASA Technical Reports Server (NTRS)

Stern, S. Alan

1992-01-01

In 1991 we detected extended 1.1 mm emission around Fomalhaut (alpha PsA) at distances in order of magnitude beyond previous detections. This emission is plausibly related to the presence of an extended comet cloud, like our Oort Cloud, and may therefore represent indirect evidence for the formation of a planetary system at Fomalhaut. We propose now to extend this work to create a map of the angular and spatial extent of this emission. Fomalhaut is the only known main-sequence, submm-resolved IR excess source besides beta Pic.

High-level expression of a specific beta-1,3-1,4-glucanase from the thermophilic fungus Paecilomyces thermophila in Pichia pastoris.

PubMed

Hua, Chengwei; Yan, Qiaojuan; Jiang, Zhengqiang; Li, Yinan; Katrolia, Priti

2010-09-01

In this study, a novel beta-1,3-1,4-glucanase gene (designated as PtLic16A) from Paecilomyces thermophila was cloned and sequenced. PtLic16A has an open reading frame of 945 bp, encoding 314 amino acids. The deduced amino acid sequence shares the highest identity (61%) with the putative endo-1,3(4)-beta-glucanase from Neosartorya fischeri NRRL 181. PtLic16A was cloned into a vector pPIC9K and was expressed successfully in Pichia pastoris as active extracellular beta-1,3-1,4-glucanase. The recombinant beta-1,3-1,4-glucanase (PtLic16A) was secreted predominantly into the medium which comprised up to 85% of the total extracellular proteins and reached a protein concentration of 9.1 g l(-1) with an activity of 55,300 U ml(-1) in 5-l fermentor culture. The enzyme was then purified using two steps, ion exchange chromatography, and gel filtration chromatography. The purified enzyme had a molecular mass of 38.5 kDa on SDS-PAGE. It was optimally active at pH 7.0 and a temperature of 70 degrees C. Furthermore, the enzyme exhibited strict specificity for beta-1,3-1,4-D: -glucans. This is the first report on the cloning and expression of a beta-1,3-1,4-glucanase gene from Paecilomyces sp.

NIMROD Modeling of Sawtooth Modes Using Hot-Particle Closures

NASA Astrophysics Data System (ADS)

Kruger, Scott; Jenkins, T. G.; Held, E. D.; King, J. R.

2015-11-01

In DIII-D shot 96043, RF heating gives rise to an energetic ion population that alters the sawtooth stability boundary, replacing conventional sawtooth cycles by longer-period, larger-amplitude `giant sawtooth' oscillations. We explore the use of particle-in-cell closures within the NIMROD code to numerically represent the RF-induced hot-particle distribution, and investigate the role of this distribution in determining the altered mode onset threshold and subsequent nonlinear evolution. Equilibrium reconstructions from the experimental data are used to enable these detailed validation studies. Effects of other parameters on the sawtooth behavior, such as the plasma Lundquist number and hot-particle beta-fraction, are also considered. The fast energetic particles present many challenges for the PIC closure. We review new algorithm and performance improvements to address these challenges, and provide a preliminary assessment of the efficacy of the PIC closure versus a continuum model for energetic particle modeling. We also compare our results with those of, and discuss plans for a more complete validation campaign for this discharge. Supported by US Department of Energy via the SciDAC Center for Extended MHD Modeling (CEMM).

First light of the Gemini Planet Imager

PubMed Central

Macintosh, Bruce; Graham, James R.; Ingraham, Patrick; Konopacky, Quinn; Marois, Christian; Perrin, Marshall; Poyneer, Lisa; Bauman, Brian; Barman, Travis; Burrows, Adam S.; Cardwell, Andrew; Chilcote, Jeffrey; De Rosa, Robert J.; Dillon, Daren; Doyon, Rene; Dunn, Jennifer; Erikson, Darren; Fitzgerald, Michael P.; Gavel, Donald; Goodsell, Stephen; Hartung, Markus; Hibon, Pascale; Kalas, Paul; Larkin, James; Maire, Jerome; Marchis, Franck; Marley, Mark S.; McBride, James; Millar-Blanchaer, Max; Morzinski, Katie; Norton, Andrew; Oppenheimer, B. R.; Palmer, David; Patience, Jennifer; Pueyo, Laurent; Rantakyro, Fredrik; Sadakuni, Naru; Saddlemyer, Leslie; Savransky, Dmitry; Serio, Andrew; Soummer, Remi; Sivaramakrishnan, Anand; Song, Inseok; Thomas, Sandrine; Wallace, J. Kent; Wiktorowicz, Sloane; Wolff, Schuyler

2014-01-01

The Gemini Planet Imager is a dedicated facility for directly imaging and spectroscopically characterizing extrasolar planets. It combines a very high-order adaptive optics system, a diffraction-suppressing coronagraph, and an integral field spectrograph with low spectral resolution but high spatial resolution. Every aspect of the Gemini Planet Imager has been tuned for maximum sensitivity to faint planets near bright stars. During first-light observations, we achieved an estimated H band Strehl ratio of 0.89 and a 5-σ contrast of 106 at 0.75 arcseconds and 105 at 0.35 arcseconds. Observations of Beta Pictoris clearly detect the planet, Beta Pictoris b, in a single 60-s exposure with minimal postprocessing. Beta Pictoris b is observed at a separation of 434 ± 6 milliarcseconds (mas) and position angle 211.8 ± 0.5°. Fitting the Keplerian orbit of Beta Pic b using the new position together with previous astrometry gives a factor of 3 improvement in most parameters over previous solutions. The planet orbits at a semimajor axis of 9.0−0.4+0.8 AU near the 3:2 resonance with the previously known 6-AU asteroidal belt and is aligned with the inner warped disk. The observations give a 4% probability of a transit of the planet in late 2017. PMID:24821792

First light of the Gemini Planet imager.

PubMed

Macintosh, Bruce; Graham, James R; Ingraham, Patrick; Konopacky, Quinn; Marois, Christian; Perrin, Marshall; Poyneer, Lisa; Bauman, Brian; Barman, Travis; Burrows, Adam S; Cardwell, Andrew; Chilcote, Jeffrey; De Rosa, Robert J; Dillon, Daren; Doyon, Rene; Dunn, Jennifer; Erikson, Darren; Fitzgerald, Michael P; Gavel, Donald; Goodsell, Stephen; Hartung, Markus; Hibon, Pascale; Kalas, Paul; Larkin, James; Maire, Jerome; Marchis, Franck; Marley, Mark S; McBride, James; Millar-Blanchaer, Max; Morzinski, Katie; Norton, Andrew; Oppenheimer, B R; Palmer, David; Patience, Jennifer; Pueyo, Laurent; Rantakyro, Fredrik; Sadakuni, Naru; Saddlemyer, Leslie; Savransky, Dmitry; Serio, Andrew; Soummer, Remi; Sivaramakrishnan, Anand; Song, Inseok; Thomas, Sandrine; Wallace, J Kent; Wiktorowicz, Sloane; Wolff, Schuyler

2014-09-02

The Gemini Planet Imager is a dedicated facility for directly imaging and spectroscopically characterizing extrasolar planets. It combines a very high-order adaptive optics system, a diffraction-suppressing coronagraph, and an integral field spectrograph with low spectral resolution but high spatial resolution. Every aspect of the Gemini Planet Imager has been tuned for maximum sensitivity to faint planets near bright stars. During first-light observations, we achieved an estimated H band Strehl ratio of 0.89 and a 5-σ contrast of 10(6) at 0.75 arcseconds and 10(5) at 0.35 arcseconds. Observations of Beta Pictoris clearly detect the planet, Beta Pictoris b, in a single 60-s exposure with minimal postprocessing. Beta Pictoris b is observed at a separation of 434 ± 6 milliarcseconds (mas) and position angle 211.8 ± 0.5°. Fitting the Keplerian orbit of Beta Pic b using the new position together with previous astrometry gives a factor of 3 improvement in most parameters over previous solutions. The planet orbits at a semimajor axis of [Formula: see text] near the 3:2 resonance with the previously known 6-AU asteroidal belt and is aligned with the inner warped disk. The observations give a 4% probability of a transit of the planet in late 2017.

[Accession to the PIC/S and pharmaceutical quality system in Japan].

PubMed

Katori, Noriko

2014-01-01

In March, 2012, Japan made the application for membership of the Pharmaceutical Inspection convention and Pharmaceutical Inspection Co-operation scheme (PIC/S) which is an international body of a GMP inspection. The globalization of pharmaceutical manufacturing and sales has been a driving force behind the decision to become a PIC/S member. For the application for membership, Japan's GMP inspectorate needs to fulfill PIC/S requirements, for example, the inspection organization has to have a quality system as a global standard. One of the other requirements is that the GMP inspectorate can access Official Medicines Control Laboratories (OMCL) having high analytical skills and also have a quality system based on ISO 17025. I would like to describe the process to make up a quality system in the National Institute of Health Sciences and also the circumstances around the PIC/S application in Japan.

Dissipation and particle energization in moderate to low beta turbulent plasma via PIC simulations

NASA Astrophysics Data System (ADS)

Makwana, Kirit; Li, Hui; Guo, Fan; Li, Xiaocan

2017-05-01

We simulate decaying turbulence in electron-positron pair plasmas using a fully-kinetic particle-in-cell (PIC) code. We run two simulations with moderate-to-low plasma β (the ratio of thermal pressure to magnetic pressure). The energy decay rate is found to be similar in both cases. The perpendicular wave-number spectrum of magnetic energy shows a slope between {k}\\perp -1.3 and {k}\\perp -1.1, where the perpendicular (⊥) and parallel (∥) directions are defined with respect to the magnetic field. The particle kinetic energy distribution function shows the formation of a non-thermal feature in the case of lower plasma β, with a slope close to E-1. The correlation between thin turbulent current sheets and Ohmic heating by the dot product of electric field (E) and current density (J) is investigated. Heating by the parallel E∥ · J∥ term dominates the perpendicular E⊥ · J⊥ term. Regions of strong E∥ · J∥ are spatially well-correlated with regions of intense current sheets, which also appear correlated with regions of strong E∥ in the low β simulation, suggesting an important role of magnetic reconnection in the dissipation of low β plasma turbulence.

Constructing a short form of the hierarchical personality inventory for children (HiPIC): the HiPIC-30.

PubMed

Vollrath, Margarete E; Hampson, Sarah E; Torgersen, Svenn

2016-05-01

Children's personality traits are invaluable predictors of concurrent and later mental and physical health. Several validated longer inventories for assessing the widely recognized Five-Factor Model of personality in children are available, but short forms are scarce. This study aimed at constructing a 30-item form of the 144-item Hierarchical Personality Inventory for Children (HiPIC) (Mervielde & De Fruyt, ). Participants were 1543 children aged 6-12 years (sample 1) and 3895 children aged 8 years (sample 2). Sample 1 completed the full HiPIC, from which we constructed the HiPIC-30, and the Child Behaviour Checklist (Achenbach, ). Sample 2 completed the HiPIC-30. The HiPIC-30 personality domains correlated over r = .90 with the full HiPIC domains, had good Cronbach's alphas and correlated similarly with CBCL behaviour problems and gender as the full HiPIC. The factor structures of the HiPIC-30 were convergent across samples, but the imagination factor was not clear-cut. We conclude that the HiPIC-30 is a reliable and valid questionnaire for the Five-Factor personality traits in children. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

The interaction of extreme waves with hull elements

NASA Astrophysics Data System (ADS)

Galiev, Shamil; Flay, Richard

2010-05-01

The problem of the impact of a rogue wave onto a deformable marine structure is formulated in a few publications (see, for example, a short review in http://researchspace.auckland.ac.nz/handle/2292/4474). In this paper the results from numerical and experimental investigations of the effect of cavitation on the deformation of a hull element, loaded by a wall of water, generated by an extreme ocean surface wave are considered. The hull element is modelled as a circular metal plate with the edge of the plate rigidly clamped. The plate surface is much smaller than the surface of the wave front, so that at the initial moment of the interaction, the pressure is constant on the plate surface. At the next instant, because of the plate deformation, axisymmetric loading of the plate occurs. The influences of membrane forces and plastic deformations are ignored, and therefore, the equation of plate motion has the following classical form Eh3(wrrrr+2r -1wrrrr- r-2wrr+r-3wr) = - 121- ν2)[ρhwtt+ δ(r,t)(p+ ρ0a0wt)]. Here w is the plate displacement, subscripts t and rindicate derivatives with respect to time and the radial coordinate, PIC is the plate material density, his the plate thickness, Eis Young's modulus, PIC is Poisson's ratio and p is the pressure of the incident surface wave measured on the wall, PIC is the water density, PIC is the speed of sound in water, and PIC is the normal velocity of the plate. The term PIC takes into account the effect of the deformability of the plate. Obviously, the hull of a vessel is not rigid like a solid wall, but starts to deform and to move. This motion produces a reflected pressure wave, which travels from the hull into the water wave with a magnitude equal to PIC . The normal velocity is positive so the reflected pressure PIC is negative (tensile wave). If the fluid pressure drops below some critical value pk, the wet plate surface separates from the water, and cavitation may be generated. The function δ(r,t) takes into account the effect of the hull cavitation. The function PIC or 0, and is determined during the numerical calculations. Case PIC is valid for the case with no cavitation, and the case δ(r,t) = 0 corresponds to the case with hull cavitation. The results from these calculations allow us to draw the following conclusions. 1) The pressures generated depend greatly on the irregularity of waves. In particular, the shock pressures are affected by this irregularity, making the prediction of their magnitude almost impossible. 2) In the majority of cases, the elastic deformation of thin hull elements by a short duration water wave pressure pulse is accompanied by hull cavitation. The effect of cavitation may be important, provided that the time of loading by the water wall pressure is less than the period of the fundamental frequency of the hull element oscillations. 3) The cavitation zones can enclose practically the whole wet surface and thus completely change the water loading onto the hull element, compared to the pressures that would be developed in the absence of cavitation. 4) The hull element deformation generates surface pressure and cavitation waves. 5) Cavitation interaction of extreme water waves with structures, and hull response, are complex topics, which are not well understood and are expected to be important in the design of advanced ships in the future. 6) The existence of rogue waves makes it important to re-examine some of the ideas developed earlier which are fundamental to merchant ship design.

First light of the Gemini Planet Imager

DOE PAGES

Macintosh, Bruce; Graham, James R.; Ingraham, Patrick; ...

2014-05-12

The Gemini Planet Imager is a dedicated facility for directly imaging and spectroscopically characterizing extrasolar planets. It combines a very high-order adaptive optics system, a diffraction-suppressing coronagraph, and an integral field spectrograph with low spectral resolution but high spatial resolution. Every aspect of the Gemini Planet Imager has been tuned for maximum sensitivity to faint planets near bright stars. During first-light observations, we achieved an estimated H band Strehl ratio of 0.89 and a 5-σ contrast of 10 6 at 0.75 arcseconds and 10 5 at 0.35 arcseconds. Observations of Beta Pictoris clearly detect the planet, Beta Pictoris b, inmore » a single 60-s exposure with minimal postprocessing. Beta Pictoris b is observed at a separation of 434 ± 6 milliarcseconds (mas) and position angle 211.8 ± 0.5°. Fitting the Keplerian orbit of Beta Pic b using the new position together with previous astrometry gives a factor of 3 improvement in most parameters over previous solutions. The planet orbits at a semimajor axis of 9.0 +0.8 –0.4 AU near the 3:2 resonance with the previously known 6-AU asteroidal belt and is aligned with the inner warped disk. In conclusion, the observations give a 4% probability of a transit of the planet in late 2017.« less

Chromium picolinate modulates serotonergic properties and carbohydrate metabolism in a rat model of diabetes.

PubMed

Komorowski, James R; Tuzcu, Mehmet; Sahin, Nurhan; Juturu, Vijaya; Orhan, Cemal; Ulas, Mustafa; Sahin, Kazim

2012-10-01

Chromium picolinate (CrPic) has shown both antidepressant and antidiabetic properties. In this study, the effects of CrPic on serotonergic properties and carbohydrate metabolism in diabetic rats were evaluated. Sixty male Sprague-Dawley rats were divided into four groups. (1) The control group received only standard diet (8 % fat). (2) The CrPic group was fed standard diet and CrPic (80 μg CrPic per kilogram body mass (b.m.)/day), for 10 weeks (microgram/kilogram b.m./day). (3) The HFD/STZ group fed a high-fat diet (HFD, 40 % fat) for 2 weeks and then received streptozotocin (STZ, 40 mg/kg, i.p.) (i.v.) HFD-STZ-CrPic group treated as the previous group and then were administered CrPic. CrPic administration to HFD/STZ-treated rats increased brain chromium levels and improved all measurements of carbohydrate metabolism and serotonergic properties (P<0.001). CrPic also significantly increased levels of insulin, tryptophan, and serotonin (P<0.001) in the serum and brain, and decreased cortisol levels in the serum (P<0.01). Except chromium levels, no significant effect of CrPic supplementation was detected on the overall measured parameters in the control group. CrPic administration was well tolerated without any adverse events. The results support the use of CrPic supplementation which improves serotonergic properties of brain in diabetes.

Status and future plans for open source QuickPIC

NASA Astrophysics Data System (ADS)

An, Weiming; Decyk, Viktor; Mori, Warren

2017-10-01

QuickPIC is a three dimensional (3D) quasi-static particle-in-cell (PIC) code developed based on the UPIC framework. It can be used for efficiently modeling plasma based accelerator (PBA) problems. With quasi-static approximation, QuickPIC can use different time scales for calculating the beam (or laser) evolution and the plasma response, and a 3D plasma wake field can be simulated using a two-dimensional (2D) PIC code where the time variable is ξ = ct - z and z is the beam propagation direction. QuickPIC can be thousand times faster than the normal PIC code when simulating the PBA. It uses an MPI/OpenMP hybrid parallel algorithm, which can be run on either a laptop or the largest supercomputer. The open source QuickPIC is an object-oriented program with high level classes written in Fortran 2003. It can be found at https://github.com/UCLA-Plasma-Simulation-Group/QuickPIC-OpenSource.git

Influence of wall plasma on microwave frequency and power in relativistic backward wave oscillator

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

Sun, Jun; Cao, Yibing; Teng, Yan

2015-07-15

The RF breakdown of the slow wave structure (SWS), which will lead to the generation of the wall plasma, is an important cause for pulse shortening in relativistic backward wave oscillators. Although many researchers have performed profitable studies about this issue, the influence mechanism of this factor on the microwave generation still remains not-so-clear. This paper simplifies the wall plasma with an “effective” permittivity and researches its influence on the microwave frequency and power. The dispersion relation of the SWS demonstrates that the introduction of the wall plasma will move the dispersion curves upward to some extent, which is confirmedmore » by particle-in-cell (PIC) simulations and experiments. The plasma density and volume mainly affect the dispersion relation at the upper and lower frequency limits of each mode, respectively. Meanwhile, PIC simulations show that even though no direct power absorption exists since the wall plasma is assumed to be static, the introduction of the wall plasma may also lead to the decrease in microwave power by changing the electrodynamic property of the SWS.« less

Testing COBOL Programs by Mutation. Volume I. Introduction to the CMS.1 System.

DTIC Science & Technology

1980-02-01

ALTER-OCCURS><SYMBOL TABLE location><code><x> where code = 0 means "add 1 to occurs", = 1 means "subtract 1 from occurs". 4 Insert a filler ( PIC X) in...REC. 31 01 OLD-REC. 32 03 FILLER PIC X. 33 03 OLD-KEY PIC X(12). 34 03 FILLER PIC X(67). 35S to NEdETF 36 RECORD CONTATS 90 CHARACTERS 37 LABEL RECORDS...ARE STANDARD 3S DATA RECORD IS NEd-REC. 39 01 NEd-REC. AO 03 FILLER PIC 1. Al 03 NEW-(FY PIC X(12). A2 03 FILLER PIC 1(6?). 43 ED PMTHR 44 RECORD

Cross-Modal Attention Effects in the Vestibular Cortex during Attentive Tracking of Moving Objects.

PubMed

Frank, Sebastian M; Sun, Liwei; Forster, Lisa; Tse, Peter U; Greenlee, Mark W

2016-12-14

The midposterior fundus of the Sylvian fissure in the human brain is central to the cortical processing of vestibular cues. At least two vestibular areas are located at this site: the parietoinsular vestibular cortex (PIVC) and the posterior insular cortex (PIC). It is now well established that activity in sensory systems is subject to cross-modal attention effects. Attending to a stimulus in one sensory modality enhances activity in the corresponding cortical sensory system, but simultaneously suppresses activity in other sensory systems. Here, we wanted to probe whether such cross-modal attention effects also target the vestibular system. To this end, we used a visual multiple-object tracking task. By parametrically varying the number of tracked targets, we could measure the effect of attentional load on the PIVC and the PIC while holding the perceptual load constant. Participants performed the tracking task during functional magnetic resonance imaging. Results show that, compared with passive viewing of object motion, activity during object tracking was suppressed in the PIVC and enhanced in the PIC. Greater attentional load, induced by increasing the number of tracked targets, was associated with a corresponding increase in the suppression of activity in the PIVC. Activity in the anterior part of the PIC decreased with increasing load, whereas load effects were absent in the posterior PIC. Results of a control experiment show that attention-induced suppression in the PIVC is stronger than any suppression evoked by the visual stimulus per se. Overall, our results suggest that attention has a cross-modal modulatory effect on the vestibular cortex during visual object tracking. In this study we investigate cross-modal attention effects in the human vestibular cortex. We applied the visual multiple-object tracking task because it is known to evoke attentional load effects on neural activity in visual motion-processing and attention-processing areas. Here we demonstrate a load-dependent effect of attention on the activation in the vestibular cortex, despite constant visual motion stimulation. We find that activity in the parietoinsular vestibular cortex is more strongly suppressed the greater the attentional load on the visual tracking task. These findings suggest cross-modal attentional modulation in the vestibular cortex. Copyright © 2016 the authors 0270-6474/16/3612720-09$15.00/0.

Molecular analysis of hprt mutations induced by chromium picolinate in CHO AA8 cells.

PubMed

Coryell, Virginia H; Stearns, Diane M

2006-11-07

Chromium picolinate (CrPic) is a popular dietary supplement, marketed to the public for weight loss, bodybuilding, and control of blood sugar. Recommendations for long-term use at high dosages have led to questions regarding its safety. Previous studies have reported that CrPic can cause chromosomal aberrations and mutations. The purpose of the current work was to compare the mutagenicity of CrPic as a suspension in acetone versus a solution in DMSO, and to characterize the hprt mutations induced by CrPic in CHO AA8 cells. Treatments of 2% acetone or 2% DMSO alone produced no significant increase in 6-thioguanine (6-TG)-resistant mutants after 48 h exposures. Mutants resistant to 6-TG were generated by exposing cells for 48 h to 80 microg/cm(2) CrPic in acetone or to 1.0mM CrPic in DMSO. CrPic in acetone produced an average induced mutation frequency (MF) of 56 per 10(6) surviving cells relative to acetone solvent. CrPic in acetone was 3.5-fold more mutagenic than CrPic in DMSO, which produced an MF of 16.2. Characterization of 61 total mutations in 48 mutants generated from exposure to CrPic in acetone showed that base substitutions comprised 33% of the mutations, with transversions being predominant; deletions made up 62% of the mutations, with one-exon deletions predominating; and 1-4 bp insertions made up 5% of the characterized mutations. CrPic induced a statistically greater number of deletions and a statistically smaller number of base substitutions than have been measured in spontaneously generated mutants. These data confirm previous studies showing that CrPic is mutagenic, and support the contention that further study is needed to verify the safety of CrPic for human consumption.

Speed-limited particle-in-cell (SLPIC) simulation

NASA Astrophysics Data System (ADS)

Werner, Gregory; Cary, John; Jenkins, Thomas

2016-10-01

Speed-limited particle-in-cell (SLPIC) simulation is a new method for particle-based plasma simulation that allows increased timesteps in cases where the timestep is determined (e.g., in standard PIC) not by the smallest timescale of interest, but rather by an even smaller physical timescale that affects numerical stability. For example, SLPIC need not resolve the plasma frequency if plasma oscillations do not play a significant role in the simulation; in contrast, standard PIC must usually resolve the plasma frequency to avoid instability. Unlike fluid approaches, SLPIC retains a fully-kinetic description of plasma particles and includes all the same physical phenomena as PIC; in fact, if SLPIC is run with a PIC-compatible timestep, it is identical to PIC. However, unlike PIC, SLPIC can run stably with larger timesteps. SLPIC has been shown to be effective for finding steady-state solutions for 1D collisionless sheath problems, greatly speeding up computation despite a large ion/electron mass ratio. SLPIC is a relatively small modification of standard PIC, with no complexities that might degrade parallel efficiency (compared to PIC), and is similarly compatible with PIC field solvers and boundary conditions.

Origin of superluminal radio jets in microquasars

NASA Astrophysics Data System (ADS)

Yadav, J. S.; Bhandare, R. S.

In Microquasars, superluminal radio jets are seen at large distances from few hundred AU to 5000 AU with very high radio luminosity. We suggest that these superluminal jets are due to internal shocks which form in the previously generated slowly moving wind (from the accretion disk or the companion star) with beta < 0.01 as the fast moving discrete jet with beta sim 1 catches up and interacts with it. The black hole X-ray binaries with transient radio emission (mostly LMXBs) produce superluminal jets with beta_app > 1 when the accretion rate is high and the bolometric luminosity, L_bol approaches the Eddington Luminosity, L_Edd. On the other hand, the black hole X-ray binaries with persistent radio emission (mostly HMXBs) produce superluminal jets with beta_app < 1 at relatively low accretion rate. Our work here brings Galactic microquasars closer to extragalactic AGNs and quasars as the environment plays an important role in the formation of superluminal jets.

Three-Dimensional Simulations of Electron Beams Focused by Periodic Permanent Magnets

NASA Technical Reports Server (NTRS)

Kory, Carol L.

1999-01-01

A fully three-dimensional (3D) model of an electron beam focused by a periodic permanent magnet (PPM) stack has been developed. First, the simulation code MAFIA was used to model a PPM stack using the magnetostatic solver. The exact geometry of the magnetic focusing structure was modeled; thus, no approximations were made regarding the off-axis fields. The fields from the static solver were loaded into the 3D particle-in-cell (PIC) solver of MAFIA where fully 3D behavior of the beam was simulated in the magnetic focusing field. The PIC solver computes the time-integration of electromagnetic fields simultaneously with the time integration of the equations of motion of charged particles that move under the influence of those fields. Fields caused by those moving charges are also taken into account; thus, effects like space charge and magnetic forces between particles are fully simulated. The electron beam is simulated by a number of macro-particles. These macro-particles represent a given charge Q amounting to that of several million electrons in order to conserve computational time and memory. Particle motion is unrestricted, so particle trajectories can cross paths and move in three dimensions under the influence of 3D electric and magnetic fields. Correspondingly, there is no limit on the initial current density distribution of the electron beam, nor its density distribution at any time during the simulation. Simulation results including beam current density, percent ripple and percent transmission will be presented, and the effects current, magnetic focusing strength and thermal velocities have on beam behavior will be demonstrated using 3D movies showing the evolution of beam characteristics in time and space. Unlike typical beam optics models, this 3D model allows simulation of asymmetric designs such as non- circularly symmetric electrostatic or magnetic focusing as well as the inclusion of input/output couplers.

Dust discs around low-mass main-sequence stars

NASA Technical Reports Server (NTRS)

Wolstencroft, R. D.; Walker, Helen J.

1988-01-01

The current understanding of the formation of circumstellar disks as a natural accompaniment to the process of low-mass star formation is examined. Models of the thermal emission from the dust disks around the prototype stars Alpha Lyr, Alpha PsA, Beta Pic, and Epsilon Eri are discussed, which indicate that the central regions of three of these disks are almost devoid of dust within radii ranging between 17 and 26 AU, with the temperature of the hottest zone lying between about 115 and 210 K. One possible explanation of the dust-free zones is the presence of a planet at the inner boundary of each cloud which sweeps up grains crossing its orbit.

Plasmon-induced charge separation: chemistry and wide applications.

PubMed

Tatsuma, Tetsu; Nishi, Hiroyasu; Ishida, Takuya

2017-05-01

Recent development of nanoplasmonics has stimulated chemists to utilize plasmonic nanomaterials for efficient and distinctive photochemical applications, and physicists to boldly go inside the "wet" chemistry world. The discovery of plasmon-induced charge separation (PICS) has even accelerated these trends. On the other hand, some confusion is found in discussions about PICS. In this perspective, we focus on differences between PICS and some other phenomena such as co-catalysis effect and plasmonic nanoantenna effect. In addition, materials and nanostructures suitable for PICS are shown, and characteristics and features unique to PICS are documented. Although it is well known that PICS has been applied to photovoltaics and photocatalysis, here light is shed on other applications that take better advantage of PICS, such as chemical sensing and biosensing, various photochromisms, photoswitchable functionalities and nanoscale photofabrication.

Dissipation and particle energization in moderate to low beta turbulent plasma via PIC simulations

DOE PAGES

Makwana, Kirit; Li, Hui; Guo, Fan; ...

2017-05-30

Here, we simulate decaying turbulence in electron-positron pair plasmas using a fully-kinetic particle-in-cell (PIC) code. We run two simulations with moderate-to-low plasma β (the ratio of thermal pressure to magnetic pressure). The energy decay rate is found to be similar in both cases. The perpendicular wave-number spectrum of magnetic energy shows a slope betweenmore » $${k}_{\\perp }^{-1.3}$$ and $${k}_{\\perp }^{-1.1}$$, where the perpendicular (⊥) and parallel (∥) directions are defined with respect to the magnetic field. The particle kinetic energy distribution function shows the formation of a non-thermal feature in the case of lower plasma β, with a slope close to E-1. The correlation between thin turbulent current sheets and Ohmic heating by the dot product of electric field (E) and current density (J) is investigated. By heating the parallel E∥ centerdot J∥ term dominates the perpendicular E⊥ centerdot J⊥ term. Regions of strong E∥ centerdot J∥ are spatially well-correlated with regions of intense current sheets, which also appear correlated with regions of strong E∥ in the low β simulation, suggesting an important role of magnetic reconnection in the dissipation of low β plasma turbulence.« less

Dissipation and particle energization in moderate to low beta turbulent plasma via PIC simulations

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

Makwana, Kirit; Li, Hui; Guo, Fan

Here, we simulate decaying turbulence in electron-positron pair plasmas using a fully-kinetic particle-in-cell (PIC) code. We run two simulations with moderate-to-low plasma β (the ratio of thermal pressure to magnetic pressure). The energy decay rate is found to be similar in both cases. The perpendicular wave-number spectrum of magnetic energy shows a slope betweenmore » $${k}_{\\perp }^{-1.3}$$ and $${k}_{\\perp }^{-1.1}$$, where the perpendicular (⊥) and parallel (∥) directions are defined with respect to the magnetic field. The particle kinetic energy distribution function shows the formation of a non-thermal feature in the case of lower plasma β, with a slope close to E-1. The correlation between thin turbulent current sheets and Ohmic heating by the dot product of electric field (E) and current density (J) is investigated. By heating the parallel E∥ centerdot J∥ term dominates the perpendicular E⊥ centerdot J⊥ term. Regions of strong E∥ centerdot J∥ are spatially well-correlated with regions of intense current sheets, which also appear correlated with regions of strong E∥ in the low β simulation, suggesting an important role of magnetic reconnection in the dissipation of low β plasma turbulence.« less

The use of polyion complex micelles to enhance the oral delivery of salmon calcitonin and transport mechanism across the intestinal epithelial barrier.

PubMed

Li, Na; Li, Xin-Ru; Zhou, Yan-Xia; Li, Wen-Jing; Zhao, Yong; Ma, Shu-Jin; Li, Jin-Wen; Gao, Ya-Jie; Liu, Yan; Wang, Xing-Lin; Yin, Dong-Dong

2012-12-01

The objective of the present study was to demonstrate the effect of polyanionic copolymer mPEG-grafted-alginic acid (mPEG-g-AA)-based polyion complex (PIC) micelles on enhancing the oral absorption of salmon calcitonin (sCT) in vivo and in vitro and identify the transepithelial transport mechanism of PIC micelles across the intestinal barrier. mPEG-g-AA was first successfully synthesized and characterized in cytotoxicity. The PIC micelles were approximately of 72 nm in diameter with a narrow distribution. The extremely significant enhancement of hypocalcemia efficacy of sCT-loaded PIC micelles in rats was evidenced by intraduodenal administration in comparison with sCT solution. The presence of mPEG-grafted-chitosan in PIC micelles had no favorable effect on this action in the referred content. In the Caco-2 transport studies, PIC micelles could significantly increase the permeability of sCT across Caco-2 monolayers without significantly affecting transepithelial electrical resistance values during the transport study. No evident alterations in the F-actin cytoskeleton were detected by confocal microscope observation following treatment of the cell monolayers with PIC micelles, which further certified the incapacity of PIC micelles to open the intercellular tight junctions. In addition, TEM observations showed that the intact PIC micelles were transported across the everted gut sac. These suggested that the transport of PIC micelles across Caco-2 cell monolayers involve a predominant transcytosis mechanism via endocytosis rather than paracellular pathway. Furthermore, PIC micelles were localized in both the cytoplasm and the nuclei observed by CLSM. Therefore, PIC micelles might be a potentially applicable tool for enhancing the oral absorption of cationic peptide and protein drugs. Copyright © 2012 Elsevier Ltd. All rights reserved.

ESCAP/POPIN Expert Working Group on Development of Population Information Centres and Networks, 20-23 June 1984, Bangkok, Thailand.

PubMed

1984-07-01

An overview of current population information programs at the regional, national, and global level was presented at a meeting of the Expert Working Group on Development of Population Information Centres and Networks. On the global level, the decentralized Population Information Network (POPIN) was established, consisting of population libraries, clearinghouses, information systems, and documentation centers. The Economic and Social Commission for Asia and the Pacific (ESCAP) Regional Population Information Centre (PIC) has actively promoted the standardization of methodologies for the collection and processing of data, the use of compatible terminology, adoption of classification systems, computer-assisted data and information handling, and improved programs of publication and infomration dissemination, within and among national centers. Among the national PICs, 83% are attached to the primary national family planning/fertility control unit and 17% are attached to demographic data, research, and analysis units. Lack of access to specialized information handling equipment such as microcomputers, word processors, and computer terminals remains a problem for PICs. Recommendations were made by the Expert Working Group to improve the functions of PICs: 1) the mandate and resoponsibilities of the PIC should be explicilty stated; 2) PICs should collect, process, and disseminate population information in the most effective format to workers in the population feild; 3) PICs should be given flexibility in the performance of activitites by their governing bodies; 4) short-term training should be provided in computerization and dissemination of information; 5) research and evaluation mechanisms for PIC activities should be developed; 6) PIC staff should prepare policy briefs for decision makers; 7) access to parent organizations should be given to nongovernment PICs; 8) study tours to foreign PICs should be organized for PIC staff; and 9) on-the-job training in indexing and abstracting should be provided. Networking among PICs can be further facilitated by written acquisition policies, automation of bibliographic information, common classification systems, and exchange of ideas and experience between various systems.

Comparison of Children With and Without ADHD on a New Pictorial Self-Assessment of Executive Functions.

PubMed

Bar-Ilan, Ruthie Traub; Cohen, Noa; Maeir, Adina

We examined the Pictorial Interview of Children's Metacognition and Executive Functions' (PIC-ME's) reliability and validity, targeting children's appraisal of their executive function (EF) in daily life. One hundred children with attention deficit hyperactivity disorder (ADHD) and 44 typically developing children (ages 5-10 yr) completed the PIC-ME. Parents completed the PIC-ME and Behavior Rating Inventory of Executive Function (BRIEF). Cronbach's α for the child PIC-ME was .914. A high correlation was found between the parent PIC-ME total and the BRIEF (r = .724). Comparisons between groups revealed significant differences on the parent PIC-ME (p < .0001) but none on the child PIC-ME. Children with ADHD identified a median of eight EF challenges they wanted to set as treatment goals. Results support the PIC-ME's initial reliability and validity among children with ADHD. Children were able to identify several EF challenges and engage in goal setting. Copyright © 2018 by the American Occupational Therapy Association, Inc.

Precise engineering of siRNA delivery vehicles to tumors using polyion complexes and gold nanoparticles.

PubMed

Kim, Hyun Jin; Takemoto, Hiroyasu; Yi, Yu; Zheng, Meng; Maeda, Yoshinori; Chaya, Hiroyuki; Hayashi, Kotaro; Mi, Peng; Pittella, Frederico; Christie, R James; Toh, Kazuko; Matsumoto, Yu; Nishiyama, Nobuhiro; Miyata, Kanjiro; Kataoka, Kazunori

2014-09-23

For systemic delivery of siRNA to solid tumors, a size-regulated and reversibly stabilized nanoarchitecture was constructed by using a 20 kDa siRNA-loaded unimer polyion complex (uPIC) and 20 nm gold nanoparticle (AuNP). The uPIC was selectively prepared by charge-matched polyionic complexation of a poly(ethylene glycol)-b-poly(L-lysine) (PEG-PLL) copolymer bearing ∼40 positive charges (and thiol group at the ω-end) with a single siRNA bearing 40 negative charges. The thiol group at the ω-end of PEG-PLL further enabled successful conjugation of the uPICs onto the single AuNP through coordinate bonding, generating a nanoarchitecture (uPIC-AuNP) with a size of 38 nm and a narrow size distribution. In contrast, mixing thiolated PEG-PLLs and AuNPs produced a large aggregate in the absence of siRNA, suggesting the essential role of the preformed uPIC in the formation of nanoarchitecture. The smart uPIC-AuNPs were stable in serum-containing media and more resistant against heparin-induced counter polyanion exchange, compared to uPICs alone. On the other hand, the treatment of uPIC-AuNPs with an intracellular concentration of glutathione substantially compromised their stability and triggered the release of siRNA, demonstrating the reversible stability of these nanoarchitectures relative to thiol exchange and negatively charged AuNP surface. The uPIC-AuNPs efficiently delivered siRNA into cultured cancer cells, facilitating significant sequence-specific gene silencing without cytotoxicity. Systemically administered uPIC-AuNPs showed appreciably longer blood circulation time compared to controls, i.e., bare AuNPs and uPICs, indicating that the conjugation of uPICs onto AuNP was crucial for enhancing blood circulation time. Finally, the uPIC-AuNPs efficiently accumulated in a subcutaneously inoculated luciferase-expressing cervical cancer (HeLa-Luc) model and achieved significant luciferase gene silencing in the tumor tissue. These results demonstrate the strong potential of uPIC-AuNP nanoarchitectures for systemic siRNA delivery to solid tumors.

Effects of chromium(III) picolinate on cortisol and DHEAs secretion in H295R human adrenocortical cells.

PubMed

Kim, Beob G; Adams, Julye M; Jackson, Brian A; Lindemann, Merlin D

2010-02-01

Dietary chromium(III) picolinate (CrPic) effects on circulating steroid hormones have been reported in various experimental animals. However, direct effects of CrPic on adrenocortical steroidogenesis are uncertain. Therefore, the objective was to determine the effects of CrPic on cortisol and dehydroepiandrosterone sulfate (DHEAs) secretion from H295R cells. In experiment 1, a 24-h exposure to CrPic (0 to 200 microM) had both linear (p < 0.001) and quadratic (p < 0.001) effects on cortisol secretion from forskolin-stimulated cells with the highest cortisol secretion at 0.1 microM of CrPic and the lowest at 200 microM of CrPic. In experiment 2, a 48-h exposure to CrPic (200 microM) decreased cortisol (p < 0.07) release from forskolin-stimulated cells during a 24-h collection period. In experiment 3, a 48-h exposure to CrPic (100 microM) decreased cortisol (p < 0.05) and DHEAs (p < 0.01) from forskolin-stimulated cells during a 24-h sampling period. In experiment 4, a 24-h exposure to forskolin followed by a 24-h exposure to both forskolin and CrPic (100 and 200 microM) decreased both cortisol and DHEAs secretion (p < 0.01). This study suggests that at high concentrations, CrPic inhibits aspects of steroidogenesis in agonist-stimulated adrenocortical cells.

PIC Activation through Functional Interplay between Mediator and TFIIH.

PubMed

Malik, Sohail; Molina, Henrik; Xue, Zhu

2017-01-06

The multiprotein Mediator coactivator complex functions in large part by controlling the formation and function of the promoter-bound preinitiation complex (PIC), which consists of RNA polymerase II and general transcription factors. However, precisely how Mediator impacts the PIC, especially post-recruitment, has remained unclear. Here, we have studied Mediator effects on basal transcription in an in vitro transcription system reconstituted from purified components. Our results reveal a close functional interplay between Mediator and TFIIH in the early stages of PIC development. We find that under conditions when TFIIH is not normally required for transcription, Mediator actually represses transcription. TFIIH, whose recruitment to the PIC is known to be facilitated by the Mediator, then acts to relieve Mediator-induced repression to generate an active form of the PIC. Gel mobility shift analyses of PICs and characterization of TFIIH preparations carrying mutant XPB translocase subunit further indicate that this relief of repression is achieved through expending energy via ATP hydrolysis, suggesting that it is coupled to TFIIH's established promoter melting activity. Our interpretation of these results is that Mediator functions as an assembly factor that facilitates PIC maturation through its various stages. Whereas the overall effect of the Mediator is to stimulate basal transcription, its initial engagement with the PIC generates a transcriptionally inert PIC intermediate, which necessitates energy expenditure to complete the process. Copyright © 2016 Elsevier Ltd. All rights reserved.

Prevalence and characteristics of plateau iris configuration among American Caucasian, American Chinese and mainland Chinese subjects.

PubMed

Li, Yingjie; Wang, Ye Elaine; Huang, Guofu; Wang, Dandan; He, Mingguang; Qiu, Mary; Lin, Shan

2014-04-01

To investigate the prevalence, risk factors and characteristics of plateau iris configuration (PIC) among American Caucasian, American Chinese and mainland Chinese. This multicentre, cross-sectional study of non-glaucomatous subjects (40-80 years) included 111 American Caucasian, 116 American Chinese and 110 mainland Chinese. Prevalence of PIC based on ultrasound biomicroscopy imaging was compared among the different ethnic groups. Risk factors and anterior segment optical coherence tomography-measured iris and angle parameters in eyes with PIC were compared. The prevalence of PIC was 25.2% in American Caucasian, 24.1% in American Chinese and 20.9% in mainland Chinese (p=0.73). The presence of PIC was associated with more positive spherical equivalence (OR=1.31, p=0.002) and shorter axial length (OR=0.75, p=0.04). There were significant differences in angle recess area (ARA) (p=0.04), IT750 (p=0.007) and IT2000 (p<0.001) between Chinese and Caucasians who have PIC. The prevalence of PIC did not differ among American Caucasian, American Chinese and mainland Chinese. PIC was associated with non-myopia and shorter axial length. Chinese eyes with PIC had smaller ARA and thicker irides than Caucasian ones. PIC might be a physiological variation of the iris and ciliary body that exists in normal eyes, both in Chinese and Caucasians.

Plasmon-induced charge separation: chemistry and wide applications

PubMed Central

Nishi, Hiroyasu; Ishida, Takuya

2017-01-01

Recent development of nanoplasmonics has stimulated chemists to utilize plasmonic nanomaterials for efficient and distinctive photochemical applications, and physicists to boldly go inside the “wet” chemistry world. The discovery of plasmon-induced charge separation (PICS) has even accelerated these trends. On the other hand, some confusion is found in discussions about PICS. In this perspective, we focus on differences between PICS and some other phenomena such as co-catalysis effect and plasmonic nanoantenna effect. In addition, materials and nanostructures suitable for PICS are shown, and characteristics and features unique to PICS are documented. Although it is well known that PICS has been applied to photovoltaics and photocatalysis, here light is shed on other applications that take better advantage of PICS, such as chemical sensing and biosensing, various photochromisms, photoswitchable functionalities and nanoscale photofabrication. PMID:28507702

beta-Phenylethylamine modulates acetylcholine release in the rat striatum: involvement of a dopamine D(2) receptor mechanism.

PubMed

Kato, M; Ishida, K; Chuma, T; Abe, K; Shigenaga, T; Taguchi, K; Miyatake, T

2001-04-20

We examined the effects of beta-phenylethylamine on striatal acetylcholine release in freely moving rats using in vivo microdialysis. beta-Phenylethylamine at 12.5 mg/kg, i.p. did not affect acetylcholine release in the striatum, whereas 25 and 50 mg/kg, i.p. immediately induced an increase in acetylcholine release in the striatum at 15-45 min. This increase following intraperitoneal administration of beta-phenylethylamine (25 mg/kg) was not affected by locally applied SCH-23390 (R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine, 10 microM), a dopamine D(1) receptor antagonist, nor by raclopride (10 microM), a dopamine D(2) receptor antagonist. The increased release of acetylcholine induced by beta-phenylethylamine was suppressed by local infusion of tetrodotoxin (1 microM). In contrast, the extracellular acetylcholine level in the striatum was significantly decreased by local application of beta-phenylethylamine (10 and 100 microM) in the striatum via a microdialysis probe. The decrease was completely blocked by local co-application of raclopride (10 microM). The beta-phenylethylamine-induced decrease in striatal acetylcholine release was not affected by co-perfusion with SCH-23390 (10 microM). These results indicate that systemic administration of beta-phenylethylamine increases acetylcholine release, whereas locally applied beta-phenylethylamine decreases striatal acetylcholine release in freely moving rats. Furthermore, the dopaminergic system, through the dopamine D(2) receptor, is involved in the locally applied beta-phenylethylamine-induced decrease in acetylcholine in the striatum.

Tuning the Size of Nanoassembles: A Hierarchical Transfer of Information from Dendrimers to Polyion Complexes.

PubMed

Amaral, Sandra P; Tawara, Maun H; Fernandez-Villamarin, Marcos; Borrajo, Erea; Martínez-Costas, José; Vidal, Anxo; Riguera, Ricardo; Fernandez-Megia, Eduardo

2018-05-04

The generation of dendrimers is a powerful tool in the control of the size and biodistribution of polyion complexes (PIC). Using a combinatorial screening of six dendrimers (18-243 terminal groups) and five oppositely charged PEGylated copolymers, a dendrimer-to-PIC hierarchical transfer of structural information was revealed with PIC diameters that increased from 80 to 500 nm on decreasing the dendrimer generation. This rise in size, which was also accompanied by a micelle-to-vesicle transition, is interpreted according to a cone- to rod-shaped progression in the architecture of the unit PIC (uPIC). This precise size tuning enabled dendritic PICs to act as nanorulers for controlled biodistribution. Overall, a domino-like control of the size and biological properties of PIC that is not attainable with linear polymers is feasible through dendrimer generation. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Inter-annual Variability in Global Suspended Particulate Inorganic Carbon Inventory Using Space-based Measurements

NASA Astrophysics Data System (ADS)

Hopkins, J.; Balch, W. M.; Henson, S.; Poulton, A. J.; Drapeau, D.; Bowler, B.; Lubelczyk, L.

2016-02-01

Coccolithophores, the single celled phytoplankton that produce an outer covering of calcium carbonate coccoliths, are considered to be the greatest contributors to the global oceanic particulate inorganic carbon (PIC) pool. The reflective coccoliths scatter light back out from the ocean surface, enabling PIC concentration to be quantitatively estimated from ocean color satellites. Here we use datasets of AQUA MODIS PIC concentration from 2003-2014 (using the recently-revised PIC algorithm), as well as statistics on coccolithophore vertical distribution derived from cruises throughout the world ocean, to estimate the average global (surface and integrated) PIC standing stock and its associated inter-annual variability. In addition, we divide the global ocean into Longhurst biogeochemical provinces, update the PIC biomass statistics and identify those regions that have the greatest inter-annual variability and thus may exert the greatest influence on global PIC standing stock and the alkalinity pump.

46 CFR 13.301 - Original application for “Tankerman-PIC (Barge)” endorsement.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Original application for âTankerman-PIC (Barge)â endorsement. 13.301 Section 13.301 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE....301 Original application for “Tankerman-PIC (Barge)” endorsement. Each applicant for a “Tankerman-PIC...

Peroxydisulfate activation by [RuII(tpy)(pic)(H2O)]+. Kinetic, mechanistic and anti-microbial activity studies.

PubMed

Chatterjee, Debabrata; Banerjee, Priyabrata; Bose, Jagadeesh C K; Mukhopadhyay, Sudit

2012-03-07

The oxidation of [Ru(II)(tpy)(pic)H(2)O](+) (tpy = 2,2',6',2''-terpyridine; pic(-) = picolinate) by peroxidisulfate (S(2)O(8)(2-)) as precursor oxidant has been investigated kinetically by UV-VIS, IR and EPR spectroscopy. The overall oxidation of Ru(II)- to Ru(IV)-species takes place in a consecutive manner involving oxidation of [Ru(II)(tpy)(pic)H(2)O](+) to [Ru(III)(tpy)(pic)(OH)](+), and its further oxidation of to the ultimate product [Ru(IV)(tpy)(pic)(O)](+) complex. The time course of the reaction was followed as a function of [S(2)O(8)(2-)], ionic strength (I) and temperature. Kinetic data and activation parameters are interpreted in terms of an outer-sphere electron transfer mechanism. Anti-microbial activity of Ru(II)(tpy)(pic)H(2)O](+) complex by inhibiting the growth of Escherichia coli DH5α in presence of peroxydisulfate has been explored, and the results of the biological studies have been discussed in terms of the [Ru(IV)(tpy)(pic)(O)](+) mediated cleavage of chromosomal DNA of the bacteria.

Development of the micro pixel chamber based on MEMS technology

NASA Astrophysics Data System (ADS)

Takemura, T.; Takada, A.; Kishimoto, T.; Komura, S.; Kubo, H.; Matsuoka, Y.; Miuchi, K.; Miyamoto, S.; Mizumoto, T.; Mizumura, Y.; Motomura, T.; Nakamasu, Y.; Nakamura, K.; Oda, M.; Ohta, K.; Parker, J. D.; Sawano, T.; Sonoda, S.; Tanimori, T.; Tomono, D.; Yoshikawa, K.

2018-02-01

Micro pixel chambers (μ-PIC) are gaseous two-dimensional imaging detectors originally manufactured using printed circuit board (PCB) technology. They are used in MeV gamma-ray astronomy, medicalimaging, neutron imaging, the search for dark matter, and dose monitoring. The position resolution of the present μ-PIC is approximately 120 μm (RMS), however some applications require a fine position resolution of less than 100 μm. To this end, we have started to develop a μ-PIC based on micro electro mechanical system (MEMS) technology, which provides better manufacturing accuracy than PCB technology. Our simulation predicted the gains of MEMS μ-PICs to be twice those of PCB μ-PICs at the same anode voltage. We manufactured two MEMS μ-PICs and tested them to study their behavior. In these experiments, we successfully operated the fabricatedMEMS μ-PICs and we achieved a maximum gain of approximately 7×103 and collected their energy spectra under irradiation of X-rays from 55Fe. However, the measured gains of the MEMS μ-PICs were less than half of the values predicted in the simulations. We postulated that the gains of the MEMS μ-PICs are diminished by the effect of the silicon used as a semiconducting substrate.

Storage of Maize in Purdue Improved Crop Storage (PICS) Bags

PubMed Central

2017-01-01

Interest in using hermetic technologies as a pest management solution for stored grain has risen in recent years. One hermetic approach, Purdue Improved Crop Storage (PICS) bags, has proven successful in controlling the postharvest pests of cowpea. This success encouraged farmers to use of PICS bags for storing other crops including maize. To assess whether maize can be safely stored in PICS bags without loss of quality, we carried out laboratory studies of maize grain infested with Sitophilus zeamais (Motshulsky) and stored in PICS triple bags or in woven polypropylene bags. Over an eight month observation period, temperatures in the bags correlated with ambient temperature for all treatments. Relative humidity inside PICS bags remained constant over this period despite the large changes that occurred in the surrounding environment. Relative humidity in the woven bags followed ambient humidity closely. PICS bags containing S. zeamais-infested grain saw a significant decline in oxygen compared to the other treatments. Grain moisture content declined in woven bags, but remained high in PICS bags. Seed germination was not significantly affected over the first six months in all treatments, but declined after eight months of storage when infested grain was held in woven bags. Relative damage was low across treatments and not significantly different between treatments. Overall, maize showed no signs of deterioration in PICS bags versus the woven bags and PICS bags were superior to woven bags in terms of specific metrics of grain quality. PMID:28072835

Smart Power: New power integrated circuit technologies and their applications

NASA Astrophysics Data System (ADS)

Kuivalainen, Pekka; Pohjonen, Helena; Yli-Pietilae, Timo; Lenkkeri, Jaakko

1992-05-01

Power Integrated Circuits (PIC) is one of the most rapidly growing branches of the semiconductor technology. The PIC markets has been forecast to grow from 660 million dollars in 1990 to 1658 million dollars in 1994. It has even been forecast that at the end of the 1990's the PIC markets would correspond to the value of the whole semiconductor production in 1990. Automotive electronics will play the leading role in the development of the standard PIC's. Integrated motor drivers (36 V/4 A), smart integrated switches (60 V/30 A), solenoid drivers, integrated switch-mode power supplies and regulators are the latest standard devices of the PIC manufactures. ASIC (Application Specific Integrated Circuits) PIC solutions are needed for the same reasons as other ASIC devices: there are no proper standard devices, a company has a lot of application knowhow, which should be kept inside the company, the size of the product must be reduced, and assembly costs are wished to be reduced by decreasing the number of discrete devices. During the next few years the most probable ASIC PIC applications in Finland will be integrated solenoid and motor drivers, an integrated electronic lamp ballast circuit and various sensor interface circuits. Application of the PIC technologies to machines and actuators will strongly be increased all over the world. This means that various PIC's, either standard PIC's or full custom ASIC circuits, will appear in many products which compete with the corresponding Finnish products. Therefore the development of the PIC technologies must be followed carefully in order to immediately be able to apply the latest development in the smart power technologies and their design methods.

Seagrass meadows as a globally significant carbonate reservoir

NASA Astrophysics Data System (ADS)

Mazarrasa, I.; Marbà, N.; Lovelock, C. E.; Serrano, O.; Lavery, P. S.; Fourqurean, J. W.; Kennedy, H.; Mateo, M. A.; Krause-Jensen, D.; Steven, A. D. L.; Duarte, C. M.

2015-03-01

There has been a growing interest in quantifying the capacity of seagrass ecosystems to act as carbon sinks as a natural way of offsetting anthropogenic carbon emissions to the atmosphere. However, most of the efforts have focused on the organic carbon (POC) stocks and accumulation rates and ignored the inorganic carbon (PIC) fraction, despite important carbonate pools associated with calcifying organisms inhabiting the meadows, such as epiphytes and benthic invertebrates, and despite the relevance that carbonate precipitation and dissolution processes have in the global carbon cycle. This study offers the first assessment of the global PIC stocks in seagrass sediments using a synthesis of published and unpublished data on sediment carbonate concentration from 402 vegetated and 34 adjacent un-vegetated sites. PIC stocks in the top 1 m sediments ranged between 3 and 1660 Mg PIC ha-1, with an average of 654 ± 24 Mg PIC ha-1, exceeding about 5 fold those of POC reported in previous studies. Sedimentary carbonate stocks varied across seagrass communities, with meadows dominated by Halodule, Thalassia or Cymodocea supporting the highest PIC stocks, and tended to decrease polewards at a rate of -8 ± 2 Mg PIC ha-1 degree-1 of latitude (GLM, p < 0.0003). Using PIC concentration and estimates of sediment accretion in seagrass meadows, mean PIC accumulation rates in seagrass sediments is 126.3 ± 0.7 g PIC m-2 y-1. Based on the global extent of seagrass meadows (177 000 to 600 000 km2), these ecosystems globally store between 11 and 39 Pg of PIC in the top meter of sediment and accumulate between 22 and 76 Tg PIC y-1, representing a significant contribution to the carbonate dynamics of coastal areas. Despite that these high rates of carbonate accumulation imply CO2 emissions from precipitation, seagrass meadows are still strong CO2 sinks as demonstrates the comparison of carbon (POC and POC) stocks between vegetated and adjacent un-vegetated sediments.

Seagrass meadows as a globally significant carbonate reservoir

NASA Astrophysics Data System (ADS)

Mazarrasa, I.; Marbà, N.; Lovelock, C. E.; Serrano, O.; Lavery, P. S.; Fourqurean, J. W.; Kennedy, H.; Mateo, M. A.; Krause-Jensen, D.; Steven, A. D. L.; Duarte, C. M.

2015-08-01

There has been growing interest in quantifying the capacity of seagrass ecosystems to act as carbon sinks as a natural way of offsetting anthropogenic carbon emissions to the atmosphere. However, most of the efforts have focused on the particulate organic carbon (POC) stocks and accumulation rates and ignored the particulate inorganic carbon (PIC) fraction, despite important carbonate pools associated with calcifying organisms inhabiting the meadows, such as epiphytes and benthic invertebrates, and despite the relevance that carbonate precipitation and dissolution processes have in the global carbon cycle. This study offers the first assessment of the global PIC stocks in seagrass sediments using a synthesis of published and unpublished data on sediment carbonate concentration from 403 vegetated and 34 adjacent un-vegetated sites. PIC stocks in the top 1 m of sediment ranged between 3 and 1660 Mg PIC ha-1, with an average of 654 ± 24 Mg PIC ha-1, exceeding those of POC reported in previous studies by about a factor of 5. Sedimentary carbonate stocks varied across seagrass communities, with meadows dominated by Halodule, Thalassia or Cymodocea supporting the highest PIC stocks, and tended to decrease polewards at a rate of -8 ± 2 Mg PIC ha-1 per degree of latitude (general linear model, GLM; p < 0.0003). Using PIC concentrations and estimates of sediment accretion in seagrass meadows, the mean PIC accumulation rate in seagrass sediments is found to be 126.3 ± 31.05 g PIC m-2 yr-1. Based on the global extent of seagrass meadows (177 000 to 600 000 km2), these ecosystems globally store between 11 and 39 Pg of PIC in the top metre of sediment and accumulate between 22 and 75 Tg PIC yr-1, representing a significant contribution to the carbonate dynamics of coastal areas. Despite the fact that these high rates of carbonate accumulation imply CO2 emissions from precipitation, seagrass meadows are still strong CO2 sinks as demonstrated by the comparison of carbon (PIC and POC) stocks between vegetated and adjacent un-vegetated sediments.

Australian Validation of the Hierarchical Personality Inventory for Children (HiPIC)

ERIC Educational Resources Information Center

Hopkinson, Laura; Watt, Dianne; Roodenburg, John

2014-01-01

The Hierarchical Personality Inventory for Children (HiPIC) is a developmentally appropriate parent-report measure of the Five Factor Model (FFM) that has been validated in several European languages but only recently in English. The English translation of the HiPIC was evaluated in an Australian context. Parent-rated HiPIC scores were obtained…

Spectral comparison of directly imaged, young substellar companions using integral field spectroscopy - construction of an empiric log g sequence

NASA Astrophysics Data System (ADS)

Schmidt, T.; Neuhaüser, R.; Seifahrt, A.

2010-10-01

About 15 substellar companions with large separations (>∼50 AU) to their young primary stars and brown dwarfs are confirmed by both common proper motion and late-M / early-L type spectra. The origin and early evolution of these objects is still under debate. While often these substellar companions are regarded as brown dwarfs, they could possibly also be massive planets, the mass estimates are very uncertain so far. They are companions to primary stars or brown dwarfs in young associations and star forming regions like the TW Hya association, Upper Scorpius, Taurus, Beta Pic moving group, TucHor association, Lupus, Ophiuchus, and Chamaeleon, hence their ages and distances are well known, in contrast to free-floating brown dwarfs. An empirical classification is not possible, because a spectral sequence that is taking the lower gravity into account, is not existing. This problem leads to an apparent mismatch between spectra of old field type objects and young low-mass companions at the same effective temperature, hampering a determination of temperature and surface gravity independent from models. Now that about 15 such substellar candidates are found in associations of different ages, 1 - 35 Myrs, it is possible to study their spectra in comparison to each other using the advantage of light concentration by an adaptive optics system with their primary as guide star. Therefore we have begun the construction of an empirical log g sequence from beginning to observe all these substellar companions homogeneously using the AO-assisted integral field spectrograph SINFONI at VLT (ESO).

UNIPIC code for simulations of high power microwave devices

NASA Astrophysics Data System (ADS)

Wang, Jianguo; Zhang, Dianhui; Liu, Chunliang; Li, Yongdong; Wang, Yue; Wang, Hongguang; Qiao, Hailiang; Li, Xiaoze

2009-03-01

In this paper, UNIPIC code, a new member in the family of fully electromagnetic particle-in-cell (PIC) codes for simulations of high power microwave (HPM) generation, is introduced. In the UNIPIC code, the electromagnetic fields are updated using the second-order, finite-difference time-domain (FDTD) method, and the particles are moved using the relativistic Newton-Lorentz force equation. The convolutional perfectly matched layer method is used to truncate the open boundaries of HPM devices. To model curved surfaces and avoid the time step reduction in the conformal-path FDTD method, CP weakly conditional-stable FDTD (WCS FDTD) method which combines the WCS FDTD and CP-FDTD methods, is implemented. UNIPIC is two-and-a-half dimensional, is written in the object-oriented C++ language, and can be run on a variety of platforms including WINDOWS, LINUX, and UNIX. Users can use the graphical user's interface to create the geometric structures of the simulated HPM devices, or input the old structures created before. Numerical experiments on some typical HPM devices by using the UNIPIC code are given. The results are compared to those obtained from some well-known PIC codes, which agree well with each other.

Neuromodulation impact on nonlinear firing behavior of a reduced model motoneuron with the active dendrite

PubMed Central

Kim, Hojeong; Heckman, C. J.

2014-01-01

Neuromodulatory inputs from brainstem systems modulate the normal function of spinal motoneurons by altering the activation properties of persistent inward currents (PICs) in their dendrites. However, the effect of the PIC on firing outputs also depends on its location in the dendritic tree. To investigate the interaction between PIC neuromodulation and PIC location dependence, we used a two-compartment model that was biologically realistic in that it retains directional and frequency-dependent electrical coupling between the soma and the dendrites, as seen in multi-compartment models based on full anatomical reconstructions of motoneurons. Our two-compartment approach allowed us to systematically vary the coupling parameters between the soma and the dendrite to accurately reproduce the effect of location of the dendritic PIC on the generation of nonlinear (hysteretic) motoneuron firing patterns. Our results show that as a single parameter value for PIC activation was either increased or decreased by 20% from its default value, the solution space of the coupling parameter values for nonlinear firing outputs was drastically reduced by approximately 80%. As a result, the model tended to fire only in a linear mode at the majority of dendritic PIC sites. The same results were obtained when all parameters for the PIC activation simultaneously changed only by approximately ±10%. Our results suggest the democratization effect of neuromodulation: the neuromodulation by the brainstem systems may play a role in switching the motoneurons with PICs at different dendritic locations to a similar mode of firing by reducing the effect of the dendritic location of PICs on the firing behavior. PMID:25309410

The long-term quality of life in patients with persistent inflammation-immunosuppression and catabolism syndrome after severe acute pancreatitis: A retrospective cohort study.

PubMed

Yang, Na; Li, Baiqiang; Ye, Bo; Ke, Lu; Chen, Faxi; Lu, Guotao; Jiang, Fangfang; Tong, Zhihui; Li, Jieshou; Li, Weiqin

2017-12-01

To explore clinical characteristics and long-term quality of life (QOL) in severe acute pancreatitis (SAP) patients with persistent inflammation-immunosuppression and catabolism syndrome (PICS). SAP patients admitted to ICU were eligible for the retrospective cohort study if they needed prolonged intensive care (>14days). Post-ICU QOL was assessed by a questionnaire, including 36-item Short Form Health Survey (SF-36) and record of re-work in a long-term follow-up. 214 SAP patients were enrolled, in which 149 (69.6%) patients met the criteria of PICS. PICS patients had more complications and ICU days compared to non-PICS patients (P<0.001), and their post-ICU mortality was higher (P=0.046). When adjusted for confounders, PICS was independently associated with higher post-ICU mortality (hazard ratio 4.5; 95% CI, 1.2 to 16.3; P=0.024). The 36-item Short Form Health Survey (SF-36) score was lower for PICS group in six subscales (P<0.001). Only 28.8% patients in the PICS group returned to work compared to 60% patients in the non-PICS group (P=0.001) CONCLUSIONS: SAP patients with prolonged ICU stay had a high morbidity of PICS, which was a risk factor for the post-ICU mortality and poor long-term QOL. Copyright © 2017 Elsevier Inc. All rights reserved.

Characterizing Dusty Debris Disks with the Gemini Planet Imager

NASA Astrophysics Data System (ADS)

Chen, Christine; Arriaga, Pauline; Bruzzone, Sebastian; Choquet, Elodie; Debes, John H.; Donaldson, Jessica; Draper, Zachary; Duchene, Gaspard; Esposito, Thomas; Fitzgerald, Michael P.; Golimowski, David A.; Hines, Dean C.; Hinkley, Sasha; Hughes, A. Meredith; Kalas, Paul; Kolokolova, Ludmilla; Lawler, Samantha; Matthews, Brenda C.; Mazoyer, Johan; Metchev, Stanimir A.; Millar-Blanchaer, Max; Moro-Martin, Amaya; Nesvold, Erika; Padgett, Deborah; Patience, Jenny; Perrin, Marshall D.; Pueyo, Laurent; Rantakyro, Fredrik; Rodigas, Timothy; Schneider, Glenn; Soummer, Remi; Song, Inseok; Stark, Chris; Weinberger, Alycia J.; Wilner, David J.

2017-01-01

We have been awarded 87 hours of Gemini Observatory time to obtain multi-wavelength observations of HST resolved debris disks using the Gemini Planet Imager. We have executed ~51 hours of telescope time during the 2015B-2016B semesters observing 12 nearby, young debris disks. We have been using the GPI Spec and Pol modes to better constrain the properties of the circumstellar dust, specifically, measuring the near-infrared total intensity and polarization fraction colors, and searching for solid-state spectral features of nearby beta Pic-like disks. We expect that our observations will allow us to break the degeneracy among the particle properties such as composition, size, porosity, and shape. We present some early results from our observations.

A Herschel-Detected Correlation between Planets and Debris Disks

NASA Astrophysics Data System (ADS)

Bryden, Geoffrey; Krist, J. E.; Stapelfeldt, K. R.; Kennedy, G.; Wyatt, M.; Beichman, C. A.; Eiroa, C.; Marshall, J.; Maldonado, J.; Montesinos, B.; Moro-Martin, A.; Matthews, B. C.; Fischer, D.; Ardila, D. R.; Kospal, A.; Rieke, G.; Su, K. Y.

2013-01-01

The Fomalhaut, beta Pic, and HR 8799 systems each have directly imaged planets and prominent debris disks, suggesting a direct link between the two phenomena. Unbiased surveys with Spitzer, however, failed to find a statistically significant correlation. We present results from SKARPS (the Search for Kuiper belts Around Radial-velocity Planet Stars) a Herschel far-IR survey for debris disks around solar-type stars known to have orbiting planets. The identified disks are generally cold and distant 50 K/100 AU), i.e. well separated from the radial-velocity-discovered planets. Nevertheless, we find a strong correlation between the inner planets and outer disks, with disks around planet-bearing stars tending to be much brighter than those not known to have planets.

Polygonal Impact Craters on selected Minor Bodies: Rhea, Dione, Tethys, Ceres, and Vesta

NASA Astrophysics Data System (ADS)

Neidhart, Tanja; Leitner, Johannes; Firneis, Maria

2017-04-01

A polygonal impact crater (PIC) is a crater that does not have a full circular shape in plane view but consists of straight crater rim segments. PICs are common on all objects in our solar system that show a cratered surface. Previous studies showed that PICs make up about 10-25% of craters on Mercury, Venus, Mars, and the Moon [1, 2, 3, 4]. Although there have been several studies on PICs on the terrestrial planets, and the Moon there are only very few investigations on PICs on minor bodies, even though there exist surface maps of Rhea, Tethys, Dione, Ceres, and Vesta that have an appropriate resolution. The aim of this study is to get more information about the abundance and characteristics of PICs on these objects. We analysed all approved craters on Rhea, Dione, Tethys, Ceres, and Vesta using images provided by the IAU/NASA/USGS Planetary Database [5]. For the classification of PICs the definition by [2] was used which states that a crater is polygonal if it consists of at least two straight crater rim segments having a discernable angle. In total 417 impact craters were examined and 227 of them were classified as polygonal. On Rhea about 48% of the approved craters are PICs, on Dione 59%, on Tethys 34%, on Ceres 74%, and on Vesta 56%. The comparison with studies on PICs on terrestrial planets, and the Moon conducted by [1, 2, 3, 4] showed that the percentage of PICs found in this study is much higher. Most of the PICs have two or three straight rim segments and only few PICs are hexagonal or pentagonal. The mean angle between the straight rims yields 121° for Rhea, 124° for Dione, 123° for Tethys, 133° for Ceres, and 134° for Vesta. These angles are well in accordance to an average angle of 112° on Mercury [1]. Also the size distribution of PICs is in accordance to results by [4] who proved that PICs seem to favor small to middle size diameters. The largest diameters of non-polygonal craters on Vesta range from 0.6 km to 450 km while the diameters of PICs only range from 3.1 km to 53.2 km [5]. The study proves that a large number of polygonal impact craters on Rhea, Dione, Tethys, Ceres, and Vesta exist but it is still unclear why the fraction of PICs on these bodies is much higher than for terrestrial planets and the Moon. One possible solution could be the different composition of the surfaces of these bodies in comparison to the terrestrial planets but for definite answers to this question further understanding of the formation process of PICs, which is still unclear, is necessary. References: [1] Weihs G. T. et al. (2015) Planet. Space Sci., 111, 77-82. [2] Aittola M. et al. (2010) Icarus, 205, 356-363. [3] Öhman et al. (2008) Meteoritics & Planet. Sci., 43, 1605-1628. [4] Öhman et al. (2010) Geol. Soc. Spec. Pap., 465, 51-65. [5] IAU/NASA/USGS Planetary Database. (2016), http://planetarynames.wr.usgs.gov/.

Feasibility of through-time spiral generalized autocalibrating partial parallel acquisition for low latency accelerated real-time MRI of speech.

PubMed

Lingala, Sajan Goud; Zhu, Yinghua; Lim, Yongwan; Toutios, Asterios; Ji, Yunhua; Lo, Wei-Ching; Seiberlich, Nicole; Narayanan, Shrikanth; Nayak, Krishna S

2017-12-01

To evaluate the feasibility of through-time spiral generalized autocalibrating partial parallel acquisition (GRAPPA) for low-latency accelerated real-time MRI of speech. Through-time spiral GRAPPA (spiral GRAPPA), a fast linear reconstruction method, is applied to spiral (k-t) data acquired from an eight-channel custom upper-airway coil. Fully sampled data were retrospectively down-sampled to evaluate spiral GRAPPA at undersampling factors R = 2 to 6. Pseudo-golden-angle spiral acquisitions were used for prospective studies. Three subjects were imaged while performing a range of speech tasks that involved rapid articulator movements, including fluent speech and beat-boxing. Spiral GRAPPA was compared with view sharing, and a parallel imaging and compressed sensing (PI-CS) method. Spiral GRAPPA captured spatiotemporal dynamics of vocal tract articulators at undersampling factors ≤4. Spiral GRAPPA at 18 ms/frame and 2.4 mm 2 /pixel outperformed view sharing in depicting rapidly moving articulators. Spiral GRAPPA and PI-CS provided equivalent temporal fidelity. Reconstruction latency per frame was 14 ms for view sharing and 116 ms for spiral GRAPPA, using a single processor. Spiral GRAPPA kept up with the MRI data rate of 18ms/frame with eight processors. PI-CS required 17 minutes to reconstruct 5 seconds of dynamic data. Spiral GRAPPA enabled 4-fold accelerated real-time MRI of speech with a low reconstruction latency. This approach is applicable to wide range of speech RT-MRI experiments that benefit from real-time feedback while visualizing rapid articulator movement. Magn Reson Med 78:2275-2282, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Comparison between Magnetopause and Magnetotail Reconnection Processes

NASA Astrophysics Data System (ADS)

Walker, R. J.; Lapenta, G.; Berchem, J.; El-Alaoui, M.

2017-12-01

For the past two years the Magnetosphere Multiscale (MMS) mission has returned detailed observations of reconnection at Earth's dayside magnetopause and now apogee has moved into the magnetotail to enable investigations of reconnection in the plasma sheet. We have been using a combination of global magnetohydrodynamic (MHD) simulation and particle-in-cell (PIC) simulation to model the physics of the reconnection process in both regions. In these calculations, we first use the MHD simulation to model the overall magnetospheric configuration and then carry out a large implicit PIC simulation by using the resulting MHD state to set the initial and boundary conditions. In this presentation, we review the similarities and differences found between the physical processes involved in reconnection occurring in the two different regions. For instance, similar crescent shaped distribution functions have been both observed and found in simulations of reconnection at the magnetopause and in the tail current sheet. Likewise, kinetic simulations have shown that the agyrotropy (non-gyrotropy) of the electron distribution function is the cleanest indicator of the location of the electron diffusion region (EDR) of both regions. There are also significant differences between the two regions. These are mostly related to the fact that separatrices are different because the plasma density is asymmetric across the dayside magnetopause and that smaller electric and guide fields are present in the night side. For instance, the jetting plasmas from reconnection in the tail form dipolarization fronts where energy exchange occurs while flux transfer events (flux ropes) form on the magnetopause and then move away from the reconnection site without forming dipolarization fronts. However, many uncertainties remain. For example, strong waves associated with the reconnection are found in the EDR at both places but it is not understood whether the kinetic mechanisms leading to the waves are the same or different.

Polymorphisms in the phosducin (PDC) gene on chromosome 1q25-32

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

Humphries, P.; Mansergh, F.C.; Farrar, G.J.

1994-09-01

Phosducin (33 kDa protein or MEKA) is a principal water-soluble phosphoprotein in the rod and cone photoreceptor cells and pinealocytes. This protein modulates the phototransduction cascade by binding to the beta and gamma subunit complexes of transducin. The PDC gene has been mapped to 1q25-32, the region of linkage of two hereditary retinal degenerative disorders; autosomal dominant juvenile-onset open-angle glaucoma and one form of autosomal recessive RP. Using previously published sequence data, PCR primers were designed to amplify the coding and 5{prime} flanking regions of the PDC gene. Direct sequencing revealed three polymorphisms in the 5{prime} flanking region, two ofmore » which were in regions highly homologous between humans and mice. Analysis of the polymorphisms was then extended to larger population samples using SSCPE and denaturing gel analysis. The first polymorphism PDC1 resulted from an insertion of a G residue at position -653/4. Allele frequencies were determined to be 0.51 (insG) and 0.49 (normal) giving a PIC value of 0.50. A deletion of a T residue at position -488 was the basis of the PDC2 polymorphism with allele frequencies of 0.88 (normal) and 0.12 (delT) and a PIC value of 0.21. Interestingly, the allele with an inserted G residue in PDC1 always segregrated with the deleted T allele in PDC2. The third polymorphism PDC3 was caused by a T or G residue at position -1083. Allele frequencies of 0.26 (G residue) and 0.74 (T residue) were determined from an analysis of 80 individuals with an overall PIC value of 0.39. The identification of these three polymorphisms in the PDC gene will be useful for future genetic linkage studies of chromosome 1q in inherited retinopathies.« less

Effects of supplemental nanoparticle trivalent chromium on the nutrient utilization, growth performance and serum traits of broilers.

PubMed

Lin, Y C; Huang, J T; Li, M Z; Cheng, C Y; Lien, T F

2015-02-01

The aim of this study was to investigate the effect of dietary supplementation of nanoparticle trivalent chromium on nutrient utilization, growth performance and serum traits of broilers. This study included two trials. In trial 1, 32 three-week-old broilers were divided into four groups: the control, chromium chloride (CrCl3), chromium picolinate (CrPic) and nanoparticle chromium picolinate (NanoCrPic). Chromium was added at a 1200 μg/kg level to evaluate the nutrient and chromium utilization. In trial 2, 160 one-day-old broilers were randomly divided into four groups as in trial 1, with four replicates. The results of trial 1 indicated that the chromium utilization is as follows: NanoCrPic > CrPic > CrCl3 and control groups, with significant differences between groups (p < 0.05). Crude fat utilization in CrCl3 group was lower than in that the control group (p < 0.05). The results of trial 2 indicated that feed intake of 4-5 weeks showed better result in the CrCl3 group than that in the CrPic group (p < 0.05). The results of serum traits indicated that the LDL-cholesterol in the NanoCrPic groups was lower than that in the CrPic group (p < 0.05). The NanoCrpic and CrPic groups showed significantly increased serum chromium concentration when compared with the control and CrCl3 groups; the triglyceride level in the CrCl3 group was lower than that in the CrPic group (p < 0.05). This study concluded that compared with CrPic, NanoCrpic supplementation could increase chromium utilization and lower the serum LDL-cholesterol of broilers. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

Positioning irrigation of contrast cystography for diagnosis of occult vesicoureteric reflux: association with technetium-99m dimercaptosuccinic acid scans.

PubMed

Berger, Christoph; Becker, Tanja; Koen, Mark; Zeino, Mazen; Fitz, Friedrich; Beheshti, Mohsen; Wolf-Kohlmeier, Iris; Haim, Silke; Riccabona, Marcus

2013-12-01

Positioning irrigation of contrast (PIC) cystography identifies occult or PIC vesicoureteral reflux (PIC-VUR) in children with recurrent febrile urinary tract infections (UTI) but no vesicoureteric reflux (VUR) on standard voiding cystourethrogram (VCUG). We sought to identify the relationship between PIC-VUR and renal scarring in technetium-99m dimercaptosuccinic acid (DMSA) scans. We retrospectively analysed PIC cystograms and DMSA scans for 154 kidneys in 81 children (65 girls; 16 boys; median age, 4.7 years; range, 0.9-15.2). Renal scarring was graded on a scale of 0-3. DMSA scans were pathologic in 66 patients (81%). Children had experienced mean 3.8 febrile UTI (range 1-25). Forty-seven (58%) children had a history of reflux, including 15 (19%) with previous anti-reflux operations. Indications for PIC cystography were recurrence of febrile UTI after either bilateral negative VCUG (66 children) or unilateral VUR (15 children) with contralateral/bilateral scarring or reflux that had changed sides in subsequent VCUGs. PIC-VUR was bilateral in 63, unilateral in 12, and absent in 6 children. Statistically significant associations between PIC-VUR grade and severity of renal scarring were identified in inter-individual (n = 77, p = 0.017) and intra-individual (refluxing vs. nonrefluxing kidney; n = 12, p = 0.008) analyses. After excluding patients with history of VUR, statistical significance was maintained in inter-individual analysis (n = 49; p = 0.018). The data suggest an association between PIC-VUR and severity of renal scarring, and legitimise the use of PIC cystography in children with renal scarring due to recurrent febrile UTI but negative findings on VCUG. Copyright © 2012 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Quantification of Poly(I:C)-Mediated Protection against Genital Herpes Simplex Virus Type 2 Infection

PubMed Central

Herbst-Kralovetz, Melissa M.; Pyles, Richard B.

2006-01-01

Alternative strategies for controlling the growing herpes simplex virus type 2 (HSV-2) epidemic are needed. A novel class of immunomodulatory microbicides has shown promise as antiherpetics, including intravaginally applied CpG-containing oligodeoxynucleotides that stimulate toll-like receptor 9 (TLR9). In the current study, we quantified protection against experimental genital HSV-2 infection provided by an alternative nucleic acid-based TLR agonist, polyinosine-poly(C) (PIC) (TLR3 agonist). Using a protection quantification paradigm, groups of mice were PIC treated and then subdivided into groups challenged with escalating doses of HSV-2. Using this paradigm, a temporal window of PIC efficacy for single applications was defined as 1 day prior to (prophylactic) through 4 h after (therapeutic) viral challenge. PIC treatment within this window protected against 10-fold-higher HSV-2 challenges, as indicated by increased 50% infectious dose values relative to those for vehicle-treated controls. Disease resolution and survival were significantly enhanced by repetitive PIC doses. Using optimal PIC regimens, cytokine induction was evaluated in murine vaginal lavages and in human vaginal epithelial cells. Similar induction patterns were observed, with kinetics that explained the limited durability of PIC-afforded protection. Daily PIC delivery courses did not generate sustained cytokine levels in murine vaginal fluids that would be indicative of local immunotoxicity. No evidence of immunotoxicity was observed in selected organs that were analyzed following repetitive vaginal PIC doses. Animal and in vitro data indicate that PIC may prove to be a valuable preventative microbicide and/or therapeutic agent against genital herpes by increasing resistance to HSV-2 and enhancing disease resolution following a failure of prevention. PMID:17005677

The Danish version of the questionnaire on pain communication: preliminary validation in cancer patients.

PubMed

Jacobsen, R; Møldrup, C; Christrup, L; Sjøgren, P; Hansen, O B

2009-07-01

The modified version of the patients' Perceived Involvement in Care Scale (M-PICS) is a tool designed to assess cancer patients' perceptions of patient-health care provider pain communication process. The objective of this study was to examine the psychometric properties of the shortened Danish version of the M-PICS (SDM-PICS). The validated English version of the M-PICS was translated into Danish following the repeated back-translation procedure. Cancer patients were recruited for the study from specialized pain management facilities. Thirty-three patients responded to the SDM-PICS, Danish Barriers Questionnaire II, Hospital Anxiety and Depression Scale, and Brief Pain Inventory Pain Severity Scale. A factor analysis of the SDM-PICS resulted in two factors: Factor one, patient information, consisted of four items assessing the extent to which the patient shared information with his/her health care provider, and Factor two, health care provider information, consisted of four items measuring the degree to which a health care provider was perceived as the one who shares information. Two separate items addressed the perceived level of information exchange between the patient and the health care provider. The SDM-PICS total had an internal consistency of 0.88. The SDM-PICS scores were positively related to pain relief and inversely related to the measures of cognitive pain management barriers, anxiety, and reported pain levels. The SDM-PICS seems to be a reliable and valid measure of perceived patient-health care provider communication in the context of cancer pain.

Pseudospectral Model for Hybrid PIC Hall-effect Thruster Simulation

DTIC Science & Technology

2015-07-01

and Fernandez6 (hybrid- PIC ). This work follows the example of Lam and Fernandez but substitutes a spectral description in the azimuthal direction to...Paper 3. DATES COVERED (From - To) July 2015-July 2015 4. TITLE AND SUBTITLE Pseudospectral model for hybrid PIC Hall-effect thruster simulationect...of a pseudospectral azimuthal-axial hybrid- PIC HET code which is designed to explicitly resolve and filter azimuthal fluctuations in the

Influence of RNA Strand Rigidity on Polyion Complex Formation with Block Catiomers.

PubMed

Hayashi, Kotaro; Chaya, Hiroyuki; Fukushima, Shigeto; Watanabe, Sumiyo; Takemoto, Hiroyasu; Osada, Kensuke; Nishiyama, Nobuhiro; Miyata, Kanjiro; Kataoka, Kazunori

2016-03-01

Polyion complexes (b-PICs) are prepared by mixing single- or double-stranded oligo RNA (aniomer) with poly(ethylene glycol)-b-poly(L-lysine) (PEG-PLL) (block catiomer) to clarify the effect of aniomer chain rigidity on association behaviors at varying concentrations. Here, a 21-mer single-stranded RNA (ssRNA) (persistence length: 1.0 nm) and a 21-mer double-stranded RNA (small interfering RNA, siRNA) (persistence length: 62 nm) are compared. Both oligo RNAs form a minimal charge-neutralized ionomer pair with a single PEG-PLL chain, termed unit b-PIC (uPIC), at low concentrations (<≈ 0.01 mg mL(-1)). Above the critical association concentration (≈ 0.01 mg mL(-1)), ssRNA b-PICs form secondary associates, PIC micelles, with sizes up to 30-70 nm, while no such multimolecular assembly is observed for siRNA b-PICs. The entropy gain associated with the formation of a segregated PIC phase in the multimolecular PIC micelles may not be large enough for rigid siRNA strands to compensate with appreciably high steric repulsion derived from PEG chains. Chain rigidity appears to be a critical parameter in polyion complex association. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

On newly and recently recorded species of the genus Lema Fabricius (Coleoptera, Chrysomelidae, Criocerinae) from Taiwan

PubMed Central

Lee, Chi-Feng; Matsumura, Yoko

2013-01-01

Abstract New records of four species (Lema lacertosa Lacordaire, 1845, Lema diversipes Pic, 1921, Lema cyanella (Linnaeus, 1758), Lema trivittata trivittata Say, 1824 and additional information on one recently recorded species (Lema solani Fabricius, 1798) are reported for Taiwan. Lema diversipes Pic, 1921 is removed from synonymy with Lema lacertosa Lacordaire, 1845; both species are redescribed. A lectotype is designated for Lema phungi Pic, 1924. The synonymies of Lema phungi Pic, 1924 and Lema jeanvoinei Pic, 1932 with Lema lacertosa Lacordaire, 1845 are supported. A revised key to the known species in Taiwan is provided. PMID:23653513

Fully implicit Particle-in-cell algorithms for multiscale plasma simulation

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

Chacon, Luis

The outline of the paper is as follows: Particle-in-cell (PIC) methods for fully ionized collisionless plasmas, explicit vs. implicit PIC, 1D ES implicit PIC (charge and energy conservation, moment-based acceleration), and generalization to Multi-D EM PIC: Vlasov-Darwin model (review and motivation for Darwin model, conservation properties (energy, charge, and canonical momenta), and numerical benchmarks). The author demonstrates a fully implicit, fully nonlinear, multidimensional PIC formulation that features exact local charge conservation (via a novel particle mover strategy), exact global energy conservation (no particle self-heating or self-cooling), adaptive particle orbit integrator to control errors in momentum conservation, and canonical momenta (EM-PICmore » only, reduced dimensionality). The approach is free of numerical instabilities: ω peΔt >> 1, and Δx >> λ D. It requires many fewer dofs (vs. explicit PIC) for comparable accuracy in challenging problems. Significant CPU gains (vs explicit PIC) have been demonstrated. The method has much potential for efficiency gains vs. explicit in long-time-scale applications. Moment-based acceleration is effective in minimizing N FE, leading to an optimal algorithm.« less

Looking for rings and things

NASA Astrophysics Data System (ADS)

Kenworthy, Matthew

2017-04-01

It's not often that an astronomical object gets its own dedicated observatory, but as the planet Beta Pictoris b moves in front of its host star, its every move will be watched by bRing, eager to discover more about the planet's Hill sphere, explains Matthew Kenworthy.

Measuring Stability and Security in Iraq

DTIC Science & Technology

2008-12-01

majority of the country. On September 1, 2008, Anbar Province, once an AQI stronghold, transferred to Provincial Iraqi Control ( PIC ). With the...transfer of Babil and Wasit Provinces to PIC in October 2008, the ISF is now in charge of security operations in the majority of Iraq’s 18 provinces... PIC ). Security responsibility for Babil Province was handed over to the GoI on October 23, 2008, and Wasit Province transitioned to PIC on October

Intracellular pressure is a motive force for cell motion in Amoeba proteus.

PubMed

Yanai, M; Kenyon, C M; Butler, J P; Macklem, P T; Kelly, S M

1996-01-01

The cortical filament layer of free-living amoebae contains concentrated actomyosin, suggesting that it can contract and produce an internal hydrostatic pressure. We report here on direct and dynamic intracellular pressure (P(ic)) measurements in Amoeba proteus made using the servo-null technique. In resting apolar A. proteus, P(ic) increased while the cells remained immobile and at apparently constant volume. P(ic) then decreased approximately coincident with pseudopod formation. There was a positive correlation between P(ic) at the onset of movement and the rate of pseudopod formation. These results are the first direct evidence that hydrostatic pressure may be a motive force for cell motion. We postulate that contractile elements in the amoeba's cortical layer contract and increase P(ic) and that this P(ic) is utilized to overcome the viscous flow resistance of the intracellular contents during pseudopod formation.

Influence of picolinic acid on seizure susceptibility in mice.

PubMed

Cioczek-Czuczwar, Anna; Czuczwar, Piotr; Turski, Waldemar Andrzej; Parada-Turska, Jolanta

2017-02-01

The mechanism of drug resistance in epilepsy remains unknown. Picolinic acid (PIC) is an endogenous metabolite of the kynurenine pathway and a chelating agent added to dietary supplements. Both inhibitory and excitatory properties of PIC were reported. The aim of this study was to determine the influence of exogenously applied PIC upon the electroconvulsive threshold and the activity of chemical convulsants in eight models of epilepsy in mice. All experiments were performed on adult male Swiss albino mice. Electroconvulsions were induced through ear clip electrodes. The electroconvulsive threshold (current strength necessary to induce tonic seizures in 50% of the tested group - CS 50 ) was estimated for control animals and animals pretreated with PIC. To determine the possible convulsant activity of PIC, it was administered subcutaneously or intracerebroventricularly in increasing doses to calculate the CD 50 values (doses of convulsants necessary to produce seizures in 50% of the animals). Chemical convulsions were induced by challenging the animals with increasing doses of convulsant to calculate the CD 50 values. The following convulsants were used: 4-aminopyridine, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, bicuculline, N-methyl-d-aspartate, nicotine, pentylenetrazole, pilocarpine hydrochloride and strychnine nitrate. PIC significantly decreased the electroconvulsive threshold and, after intracerebroventricular injection, but not subcutaneous, produced convulsions. Of the studied convulsants, only the activity of pilocarpine hydrochloride was significantly enhanced by PIC. PIC enhances seizure activity and potentially may play a role in the pathogenesis of drug resistant epilepsy. Future studies should focus on the interactions between PIC and antiepileptic drugs. Copyright © 2016. Published by Elsevier Urban & Partner Sp. z o.o.

Integrated Work Management: PIC, Course 31884

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

Simpson, Lewis Edward

The person-in-charge (PIC) plays a key role in the integrated work management (IWM) process at Los Alamos National Laboratory (LANL, or the Laboratory) because the PIC is assigned responsibility and authority by the responsible line manager (RLM) for the overall validation, coordination, release, execution, and closeout of a work activity in accordance with IWM. This course, Integrated Work Management: PIC (Course 31884), describes the PIC’s IWM roles and responsibilities. This course also discusses IWM requirements that the PIC must meet. For a general overview of the IWM process, see self-study Course 31881, Integrated Work Management: Overview. For instruction on themore » preparer’s role, see self-study Course 31883, Integrated Work Management: Preparer.« less

Assessment of the anticonvulsant potency of various benzylamide derivatives in the mouse maximal electroshock-induced seizure threshold model.

PubMed

Świąder, Mariusz J; Paruszewski, Ryszard; Łuszczki, Jarogniew J

2016-04-01

The aim of this study was to assess the anticonvulsant potency of 6 various benzylamide derivatives [i.e., nicotinic acid benzylamide (Nic-BZA), picolinic acid 2-fluoro-benzylamide (2F-Pic-BZA), picolinic acid benzylamide (Pic-BZA), (RS)-methyl-alanine-benzylamide (Me-Ala-BZA), isonicotinic acid benzylamide (Iso-Nic-BZA), and (R)-N-methyl-proline-benzylamide (Me-Pro-BZA)] in the threshold for maximal electroshock (MEST)-induced seizures in mice. Electroconvulsions (seizure activity) were produced in mice by means of a current (sine-wave, 50Hz, 500V, strength from 4 to 18mA, ear-clip electrodes, 0.2-s stimulus duration, tonic hindlimb extension taken as the endpoint). Nic-BZA, 2F-Pic-BZA, Pic-BZA, Me-Ala-BZA, Iso-Nic-BZA, and Me-Pro-BZA administered systemically (ip) in a dose-dependent manner increase the threshold for maximal electroconvulsions in mice. Linear regression analysis of Nic-BZA, 2F-Pic-BZA, Pic-BZA, MeAla-BZA, IsoNic-BZA, and Me-Pro-BZA doses and their corresponding threshold increases allowed determining threshold increasing doses by 20% (TID20 values) that elevate the threshold in drug-treated animals over the threshold in control animals. The experimentally derived TID20 values in the MEST test for Nic-BZA, 2F-Pic-BZA, Pic-BZA, Me-Ala-BZA, Iso-Nic-BZA, and Me-Pro-BZA were 7.45mg/kg, 7.72mg/kg, 8.74mg/kg, 15.11mg/kg, 21.95mg/kg and 28.06mg/kg, respectively. The studied benzylamide derivatives can be arranged with respect to their anticonvulsant potency in the MEST test as follows: Nic-BZA>2F-Pic-BZA>Pic-BZA>Me-Ala-BZA>Iso-Nic-BZA>Me-Pro-BZA. Copyright © 2015 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Clinical studies on chromium picolinate supplementation in diabetes mellitus--a review.

PubMed

Broadhurst, C Leigh; Domenico, Philip

2006-12-01

Chromium (Cr) picolinate (CrPic) is a widely used nutritional supplement for optimal insulin function. A relationship among Cr status, diabetes, and associated pathologies has been established. Virtually all trials using CrPic supplementation for subjects with diabetes have demonstrated beneficial effects. Thirteen of 15 clinical studies (including 11 randomized, controlled studies) involving a total of 1,690 subjects (1,505 in CrPic group) reported significant improvement in at least one outcome of glycemic control. All 15 studies showed salutary effects in at least one parameter of diabetes management, including dyslipidemia. Positive outcomes from CrPic supplementation included reduced blood glucose, insulin, cholesterol, and triglyceride levels and reduced requirements for hypoglycemic medication. The greater bioavailability of CrPic compared with other forms of Cr (e.g., niacin-bound Cr or CrCl(3)) may explain its comparatively superior efficacy in glycemic and lipidemic control. The pooled data from studies using CrPic supplementation for type 2 diabetes mellitus subjects show substantial reductions in hyperglycemia and hyperinsulinemia, which equate to a reduced risk for disease complications. Collectively, the data support the safety and therapeutic value of CrPic for the management of cholesterolemia and hyperglycemia in subjects with diabetes.

Studies of extra-solar Oort clouds and the Kuiper disk

NASA Technical Reports Server (NTRS)

Stern, S. Alan

1996-01-01

We are conducting research designed to enhance our understanding of the evolution and detectability of comet clouds and disks. According to 'standard' theory, both the Kuiper Belt and the Oort Cloud are (at least in part) natural products of the planetary accumulation stage of solar system formation. One expects such assemblages to be a common attribute of other solar systems. Therefore, searches for comet disks and clouds orbiting other stars offer a new method for inferring the presence of planetary systems. This project consists of two efforts: (1) observational work to predict and search for the signatures of Oort Clouds and comet disks around other stars; and (2) modelling studies of the formation and evolution of the Kuiper Belt (KB) and similar assemblages that may reside around other stars, including beta Pic.

Effects of dietary chromium picolinate and peppermint essential oil on growth performance and blood biochemical parameters of broiler chicks reared under heat stress conditions

NASA Astrophysics Data System (ADS)

Akbari, Mohsen; Torki, Mehran

2014-08-01

A study was conducted using 240 female day-old broiler chicks to evaluate the effects of dietary chromium picolinate (CrPic), peppermint essential oil (P.mint), or their combination on growth performance and blood biochemical parameters of female broiler chicks raised under heat stress conditions (HS, 23.9 to 38 °C cycling). Average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR) were obtained from 1 to 42 days of age. Furthermore, at the end of the experiment (day 42), birds were bled to determine some blood biochemical parameters and weighed for final body weight (BW). ADFI, ADG, and BW were not influenced significantly by dietary CrPic and P.mint ( P > 0.05). A significant interaction between dietary CrPic and P.mint on FCR ( P = 0.012) was detected. FCR significantly decreased in chicks fed the diet including both CrPic and P.mint compared with the CrPic group. Significant interaction between dietary P.mint and CrPic on serum concentrations of triglycerides, glucose, and albumin were observed ( P < 0.05), but the other measured blood biochemical parameters were not statistically affected by dietary treatments ( P > 0.05). The serum concentrations of glucose, triglycerides were decreased ( P < 0.05) in broilers fed the diet including both CrPic and P.mint. Plasma chromium (Cr) content increased significantly ( P < 0.05) in birds fed the CrPic-included diet compared with the control group ( P < 0.05). From the results of the present experiment it can be concluded that dietary supplementation with combined P.mint and CrPic could have beneficial effects on some blood biochemical parameters of female chicks reared under heat stress conditions.

Effects of dietary chromium picolinate and peppermint essential oil on growth performance and blood biochemical parameters of broiler chicks reared under heat stress conditions.

PubMed

Akbari, Mohsen; Torki, Mehran

2014-08-01

A study was conducted using 240 female day-old broiler chicks to evaluate the effects of dietary chromium picolinate (CrPic), peppermint essential oil (P.mint), or their combination on growth performance and blood biochemical parameters of female broiler chicks raised under heat stress conditions (HS, 23.9 to 38 °C cycling). Average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR) were obtained from 1 to 42 days of age. Furthermore, at the end of the experiment (day 42), birds were bled to determine some blood biochemical parameters and weighed for final body weight (BW). ADFI, ADG, and BW were not influenced significantly by dietary CrPic and P.mint (P>0.05). A significant interaction between dietary CrPic and P.mint on FCR (P=0.012) was detected. FCR significantly decreased in chicks fed the diet including both CrPic and P.mint compared with the CrPic group. Significant interaction between dietary P.mint and CrPic on serum concentrations of triglycerides, glucose, and albumin were observed (P<0.05), but the other measured blood biochemical parameters were not statistically affected by dietary treatments (P>0.05). The serum concentrations of glucose, triglycerides were decreased (P<0.05) in broilers fed the diet including both CrPic and P.mint. Plasma chromium (Cr) content increased significantly (P<0.05) in birds fed the CrPic-included diet compared with the control group (P<0.05). From the results of the present experiment it can be concluded that dietary supplementation with combined P.mint and CrPic could have beneficial effects on some blood biochemical parameters of female chicks reared under heat stress conditions.

Neolinoptes gen. n., a replacement name for the net-winged beetle genus Linoptes Gorham, 1884 and a new species of Lycomorphon from Guyana (Coleoptera: Lycidae).

PubMed

Nascimento, Elynton Alves DO; Bocakova, Milada

2017-01-09

Neolinoptes gen. n. is erected to replace Linoptes Gorham, 1884, preoccupied by Linoptes Menge, 1854 (Arachnida: Araneae). Consequently, Neolinoptes imbrex (Gorham, 1884) comb. n., N. amazonicus (Pic, 1923) comb. n., N. atronotatus (Pic, 1922) comb. n., N. atripennis (Pic, 1932) comb. n. are proposed. Calocladon rubidum Gorham, 1884 is transferred to Neolinoptes. Lycomorphon iwokrama sp. n. is proposed as new to science and the genus is recorded from Guyana for the first time. Additionally, Falsocaenia irregularis var. germaini Pic, 1931 is elevated to species rank and past confusion on F. irregularis discussed. New data on geographical distribution of Falsocaenia paranana (Pic, 1922) are presented.

A portable platform for accelerated PIC codes and its application to GPUs using OpenACC

NASA Astrophysics Data System (ADS)

Hariri, F.; Tran, T. M.; Jocksch, A.; Lanti, E.; Progsch, J.; Messmer, P.; Brunner, S.; Gheller, C.; Villard, L.

2016-10-01

We present a portable platform, called PIC_ENGINE, for accelerating Particle-In-Cell (PIC) codes on heterogeneous many-core architectures such as Graphic Processing Units (GPUs). The aim of this development is efficient simulations on future exascale systems by allowing different parallelization strategies depending on the application problem and the specific architecture. To this end, this platform contains the basic steps of the PIC algorithm and has been designed as a test bed for different algorithmic options and data structures. Among the architectures that this engine can explore, particular attention is given here to systems equipped with GPUs. The study demonstrates that our portable PIC implementation based on the OpenACC programming model can achieve performance closely matching theoretical predictions. Using the Cray XC30 system, Piz Daint, at the Swiss National Supercomputing Centre (CSCS), we show that PIC_ENGINE running on an NVIDIA Kepler K20X GPU can outperform the one on an Intel Sandy bridge 8-core CPU by a factor of 3.4.

Two-way coupling of magnetohydrodynamic simulations with embedded particle-in-cell simulations

NASA Astrophysics Data System (ADS)

Makwana, K. D.; Keppens, R.; Lapenta, G.

2017-12-01

We describe a method for coupling an embedded domain in a magnetohydrodynamic (MHD) simulation with a particle-in-cell (PIC) method. In this two-way coupling we follow the work of Daldorff et al. (2014) [19] in which the PIC domain receives its initial and boundary conditions from MHD variables (MHD to PIC coupling) while the MHD simulation is updated based on the PIC variables (PIC to MHD coupling). This method can be useful for simulating large plasma systems, where kinetic effects captured by particle-in-cell simulations are localized but affect global dynamics. We describe the numerical implementation of this coupling, its time-stepping algorithm, and its parallelization strategy, emphasizing the novel aspects of it. We test the stability and energy/momentum conservation of this method by simulating a steady-state plasma. We test the dynamics of this coupling by propagating plasma waves through the embedded PIC domain. Coupling with MHD shows satisfactory results for the fast magnetosonic wave, but significant distortion for the circularly polarized Alfvén wave. Coupling with Hall-MHD shows excellent coupling for the whistler wave. We also apply this methodology to simulate a Geospace Environmental Modeling (GEM) challenge type of reconnection with the diffusion region simulated by PIC coupled to larger scales with MHD and Hall-MHD. In both these cases we see the expected signatures of kinetic reconnection in the PIC domain, implying that this method can be used for reconnection studies.

Searching for Short GRBs in Soft Gamma Rays with INTEGRAL/PICsIT

NASA Astrophysics Data System (ADS)

Rodi, James; Bazzano, Angela; Ubertini, Pietro; Natalucci, Lorenzo; Savchenko, V.; Kuulkers, E.; Ferrigno, Carlo; Bozzo, Enrico; Brandt, Soren; Chenevez, Jerome; Courvoisier, T. J.-L.; Diehl, R.; Domingo, A.; Hanlon, L.; Jourdain, E.; von Kienlin, A.; Laurent, P.; Lebrun, F.; Lutovinov, A.; Martin-Carrillo, A.; Mereghetti, S.; Roques, J.-P.; Sunyaev, R.

2018-01-01

With gravitational wave (GW) detections by the LIGO/Virgo collaboration over the past several years, there is heightened interest in gamma-ray bursts (GRBs), especially “short” GRBs (T90 <2s). The high-energy PICsIT detector (~0.2 – 10 MeV) on-board the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) is able to observe sources out to approximately 70° off-axis, making it essentially a soft gamma-ray, all-sky monitor for impulsive events, such as SGRBs. Because SGRBs typically have hard spectra with peak energies of a few hundred keV, PICsIT with its ~ 3000 cm2 collecting area is able to provide spectral information about these sources at soft gamma-ray energies.We have begun a study of PICsIT data for faint SGRBs similar to the one associated with the binary neutron star (BNS) merger GW 170817, and also are preparing for future GW triggers by developing a real-time burst analysis for PICsIT. Searching the PICsIT data for significant excesses during ~30 min-long pointings containing times of SGRBs, we have been able to differentiate between SGRBs and spurious events. Also, this work allows us to assess what fraction of reported SGRBs have been detected by PICsIT, which can be used to provide an estimate of the number of GW BNS events seen by PICsIT during the next LIGO/Virgo observing run starting in Fall 2018.

Beta oscillations in freely moving Parkinson's subjects are attenuated during deep brain stimulation.

PubMed

Quinn, Emma J; Blumenfeld, Zack; Velisar, Anca; Koop, Mandy Miller; Shreve, Lauren A; Trager, Megan H; Hill, Bruce C; Kilbane, Camilla; Henderson, Jaimie M; Brontë-Stewart, Helen

2015-11-01

Investigations into the effect of deep brain stimulation (DBS) on subthalamic (STN) beta (13-30 Hz) oscillations have been performed in the perioperative period with the subject tethered to equipment. Using an embedded sensing neurostimulator, this study investigated whether beta power was similar in different resting postures and during forward walking in freely moving subjects with Parkinson's disease (PD) and whether STN DBS attenuated beta power in a voltage-dependent manner. Subthalamic local field potentials were recorded from the DBS lead, using a sensing neurostimulator (Activa(®) PC+S, Medtronic, Inc., Food and Drug Administration- Investigational Device Exemption (IDE)-, institutional review board-approved) from 15 PD subjects (30 STNs) off medication during lying, sitting, and standing, during forward walking, and during randomized periods of 140 Hz DBS at 0 V, 1 V, and 2.5/3 V. Continuous video, limb angular velocity, and forearm electromyography recordings were synchronized with neural recordings. Data were parsed to avoid any movement or electrical artifact during resting states. Beta power was similar during lying, sitting, and standing (P = 0.077, n = 28) and during forward walking compared with the averaged resting state (P = 0.466, n = 24), although akinetic rigid PD subjects tended to exhibit decreased beta power when walking. Deep brain stimulation at 3 V and at 1 V attenuated beta power compared with 0 V (P < 0.003, n = 14), and this was voltage dependent (P < 0.001). Beta power was conserved during resting and forward walking states and was attenuated in a voltage-dependent manner during 140-Hz DBS. Phenotype may be an important consideration if this is used for closed-loop DBS. © 2015 International Parkinson and Movement Disorder Society.

PIC Simulations of Hypersonic Plasma Instabilities

NASA Astrophysics Data System (ADS)

Niehoff, D.; Ashour-Abdalla, M.; Niemann, C.; Decyk, V.; Schriver, D.; Clark, E.

2013-12-01

The plasma sheaths formed around hypersonic aircraft (Mach number, M > 10) are relatively unexplored and of interest today to both further the development of new technologies and solve long-standing engineering problems. Both laboratory experiments and analytical/numerical modeling are required to advance the understanding of these systems; it is advantageous to perform these tasks in tandem. There has already been some work done to study these plasmas by experiments that create a rapidly expanding plasma through ablation of a target with a laser. In combination with a preformed magnetic field, this configuration leads to a magnetic "bubble" formed behind the front as particles travel at about Mach 30 away from the target. Furthermore, the experiment was able to show the generation of fast electrons which could be due to instabilities on electron scales. To explore this, future experiments will have more accurate diagnostics capable of observing time- and length-scales below typical ion scales, but simulations are a useful tool to explore these plasma conditions theoretically. Particle in Cell (PIC) simulations are necessary when phenomena are expected to be observed at these scales, and also have the advantage of being fully kinetic with no fluid approximations. However, if the scales of the problem are not significantly below the ion scales, then the initialization of the PIC simulation must be very carefully engineered to avoid unnecessary computation and to select the minimum window where structures of interest can be studied. One method of doing this is to seed the simulation with either experiment or ion-scale simulation results. Previous experiments suggest that a useful configuration for studying hypersonic plasma configurations is a ring of particles rapidly expanding transverse to an external magnetic field, which has been simulated on the ion scale with an ion-hybrid code. This suggests that the PIC simulation should have an equivalent configuration; however, modeling a plasma expanding radially in every direction is computationally expensive. In order to reduce the computational expense, we use a radial density profile from the hybrid simulation results to seed a self-consistent PIC simulation in one direction (x), while creating a current in the direction (y) transverse to both the drift velocity and the magnetic field (z) to create the magnetic bubble observed in experiment. The simulation will be run in two spatial dimensions but retain three velocity dimensions, and the results will be used to explore the growth of micro-instabilities present in hypersonic plasmas in the high-density region as it moves through the simulation box. This will still require a significantly large box in order to compare with experiment, as the experiments are being performed over distances of 104 λDe and durations of 105 ωpe-1.

Submillimeter studies of main-sequence stars

NASA Technical Reports Server (NTRS)

Zuckerman, B.; Becklin, E. E.

1993-01-01

JCMT maps of the 800-micron emission from Vega, Fomalhaut, and Beta Pictoris are interpreted to indicate that they are not ringed by large reservoirs of distant orbiting dust particles that are too cold to have been detected by IRAS. A search for 800-micron emission from stars in the Pleiades and Ursa Majoris open clusters is reported. In comparison with the mass of dust particles near T Tauri and Herbig Ae stars, the JCMT data indicate a decline in dust mass during the initial 3 x 10 exp 8 yr that a star spends on the main sequence that is at least as rapid as (time) exp -2. It is estimated that in the Kuiper belt the ratio of total mass carried by small particles to that carried by comets is orders of magnitude smaller than this ratio is 1 AU from the sun. If 800-micron opacities calculated by Pollack et al. (1993) are correct, then the particles with radii less than 100 microns that dominate the FIR fluxes measured by IRAS cannot entirely account for the measured 800-micron fluxes at Vega, Beta Pic, and Fomalhaut; larger particles must be present as well.

Coupling MHD and PIC models in 2 dimensions

NASA Astrophysics Data System (ADS)

Daldorff, L.; Toth, G.; Sokolov, I.; Gombosi, T. I.; Lapenta, G.; Brackbill, J. U.; Markidis, S.; Amaya, J.

2013-12-01

Even for extended fluid plasma models, like Hall, anisotropic ion pressure and multi fluid MHD, there are still many plasma phenomena that are not well captured. For this reason, we have coupled the Implicit Particle-In-Cell (iPIC3D) code with the BATSRUS global MHD code. The PIC solver is applied in a part of the computational domain, for example, in the vicinity of reconnection sites, and overwrites the MHD solution. On the other hand, the fluid solver provides the boundary conditions for the PIC code. To demonstrate the use of the coupled codes for magnetospheric applications, we perform a 2D magnetosphere simulation, where BATSRUS solves for Hall MHD in the whole domain except for the tail reconnection region, which is handled by iPIC3D.

Leveraging social media in the stem cell sector: exploring Twitter's potential as a vehicle for public information campaigns.

PubMed

McNutt, Kathleen; Zarzeczny, Amy

2017-10-01

Our aim in this project was to explore Twitter's potential as a vehicle for an online public information campaign (PIC) focused on providing evidence-based information about stem cell therapies and the market for unproven stem cell-based interventions. We designed an online, Twitter-based PIC using classic design principles and identified a set of target intermediaries (organizations with online influence) using a network governance approach. We tracked the PIC's dissemination over a 2-month period, and evaluated it using metrics from the #SMMStandards Conclave. Participation was limited but the PIC achieved some reach and engagement. Social media based online PICs appear to have potential but also face challenges. Future research is required to better understand how to most effectively maximize their strengths.

Development of a robust pH-sensitive polyelectrolyte ionomer complex for anticancer nanocarriers

PubMed Central

Lim, Chaemin; Youn, Yu Seok; Lee, Kyung Soo; Hoang, Ngoc Ha; Sim, Taehoon; Lee, Eun Seong; Oh, Kyung Taek

2016-01-01

A polyelectrolyte ionomer complex (PIC) composed of cationic and anionic polymers was developed for nanomedical applications. Here, a poly(ethylene glycol)–poly(lactic acid)–poly(ethylene imine) triblock copolymer (PEG–PLA–PEI) and a poly(aspartic acid) (P[Asp]) homopolymer were synthesized. These polyelectrolytes formed stable aggregates through electrostatic interactions between the cationic PEI and the anionic P(Asp) blocks. In particular, the addition of a hydrophobic PLA and a hydrophilic PEG to triblock copolyelectrolytes provided colloidal aggregation stability by forming a tight hydrophobic core and steric hindrance on the surface of PIC, respectively. The PIC showed different particle sizes and zeta potentials depending on the ratio of cationic PEI and anionic P(Asp) blocks (C/A ratio). The doxorubicin (dox)-loaded PIC, prepared with a C/A ratio of 8, demonstrated pH-dependent behavior by the deprotonation/protonation of polyelectrolyte blocks. The drug release and the cytotoxicity of the dox-loaded PIC (C/A ratio: 8) increased under acidic conditions compared with physiological pH, due to the destabilization of the formation of the electrostatic core. In vivo animal imaging revealed that the prepared PIC accumulated at the targeted tumor site for 24 hours. Therefore, the prepared pH-sensitive PIC could have considerable potential as a nanomedicinal platform for anticancer therapy. PMID:26955270

Effects of the magnetic field gradient on the wall power deposition of Hall thrusters

NASA Astrophysics Data System (ADS)

Ding, Yongjie; Li, Peng; Zhang, Xu; Wei, Liqiu; Sun, Hezhi; Peng, Wuji; Yu, Daren

2017-04-01

The effect of the magnetic field gradient in the discharge channel of a Hall thruster on the ionization of the neutral gas and power deposition on the wall is studied through adopting the 2D-3V particle-in-cell (PIC) and Monte Carlo collisions (MCC) model. The research shows that by gradually increasing the magnetic field gradient while keeping the maximum magnetic intensity at the channel exit and the anode position unchanged, the ionization region moves towards the channel exit and then a second ionization region appears near the anode region. Meanwhile, power deposition on the walls decreases initially and then increases. To avoid power deposition on the walls produced by electrons and ions which are ionized in the second ionization region, the anode position is moved towards the channel exit as the magnetic field gradient is increased; when the anode position remains at the zero magnetic field position, power deposition on the walls decreases, which can effectively reduce the temperature and thermal load of the discharge channel.

Apo and InsP[subscript 3]-bound crystal structures of the ligand-binding domain of an InsP[subscript 3] receptor

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

Lin, Chun-Chi; Baek, Kyuwon; Lu, Zhe

2012-05-08

We report the crystal structures of the ligand-binding domain (LBD) of a rat inositol 1,4,5-trisphosphate receptor (InsP{sub 3}R) in its apo and InsP{sub 3}-bound conformations. Comparison of these two conformations reveals that LBD's first {beta}-trefoil fold ({beta}-TF1) and armadillo repeat fold (ARF) move together as a unit relative to its second {beta}-trefoil fold ({beta}-TF2). Whereas apo LBD may spontaneously transition between gating conformations, InsP{sub 3} binding shifts this equilibrium toward the active state.

Hot DA white dwarf model atmosphere calculations: including improved Ni PI cross-sections

NASA Astrophysics Data System (ADS)

Preval, S. P.; Barstow, M. A.; Badnell, N. R.; Hubeny, I.; Holberg, J. B.

2017-02-01

To calculate realistic models of objects with Ni in their atmospheres, accurate atomic data for the relevant ionization stages need to be included in model atmosphere calculations. In the context of white dwarf stars, we investigate the effect of changing the Ni IV-VI bound-bound and bound-free atomic data on model atmosphere calculations. Models including photoionization cross-section (PICS) calculated with AUTOSTRUCTURE show significant flux attenuation of up to ˜80 per cent shortward of 180 Å in the extreme ultraviolet (EUV) region compared to a model using hydrogenic PICS. Comparatively, models including a larger set of Ni transitions left the EUV, UV, and optical continua unaffected. We use models calculated with permutations of these atomic data to test for potential changes to measured metal abundances of the hot DA white dwarf G191-B2B. Models including AUTOSTRUCTURE PICS were found to change the abundances of N and O by as much as ˜22 per cent compared to models using hydrogenic PICS, but heavier species were relatively unaffected. Models including AUTOSTRUCTURE PICS caused the abundances of N/O IV and V to diverge. This is because the increased opacity in the AUTOSTRUCTURE PICS model causes these charge states to form higher in the atmosphere, more so for N/O V. Models using an extended line list caused significant changes to the Ni IV-V abundances. While both PICS and an extended line list cause changes in both synthetic spectra and measured abundances, the biggest changes are caused by using AUTOSTRUCTURE PICS for Ni.

Estimating Particulate Inorganic Carbon Concentrations of the Global Ocean From Ocean Color Measurements Using a Reflectance Difference Approach

NASA Astrophysics Data System (ADS)

Mitchell, C.; Hu, C.; Bowler, B.; Drapeau, D.; Balch, W. M.

2017-11-01

A new algorithm for estimating particulate inorganic carbon (PIC) concentrations from ocean color measurements is presented. PIC plays an important role in the global carbon cycle through the oceanic carbonate pump, therefore accurate estimations of PIC concentrations from satellite remote sensing are crucial for observing changes on a global scale. An extensive global data set was created from field and satellite observations for investigating the relationship between PIC concentrations and differences in the remote sensing reflectance (Rrs) at green, red, and near-infrared (NIR) wavebands. Three color indices were defined: two as the relative height of Rrs(667) above a baseline running between Rrs(547) and an Rrs in the NIR (either 748 or 869 nm), and one as the difference between Rrs(547) and Rrs(667). All three color indices were found to explain over 90% of the variance in field-measured PIC. But, due to the lack of availability of Rrs(NIR) in the standard ocean color data products, most of the further analysis presented here was done using the color index determined from only two bands. The new two-band color index algorithm was found to retrieve PIC concentrations more accurately than the current standard algorithm used in generating global PIC data products. Application of the new algorithm to satellite imagery showed patterns on the global scale as revealed from field measurements. The new algorithm was more resistant to atmospheric correction errors and residual errors in sun glint corrections, as seen by a reduction in the speckling and patchiness in the satellite-derived PIC images.

Effects of Chromium Picolinate on Food Intake and Satiety

PubMed Central

Morrison, Christopher D.; Cefalu, William T.; Martin, Corby K.; Coulon, Sandra; Geiselman, Paula; Han, Hongmei; White, Christy L.; Williamson, Donald A.

2008-01-01

Abstract Background Chromium picolinate (CrPic) has been shown to attenuate weight gain, but the mechanism underlying this effect is unknown. Methods We assessed the effect of CrPic in modulating food intake in healthy, overweight, adult women who reported craving carbohydrates (Study 1) and performed confirmatory studies in Sprague-Dawley rats (Study 2). Study 1 utilized a double-blind placebo-controlled design and randomly assigned 42 overweight adult women with carbohydrate cravings to receive 1,000 μg of chromium as CrPic or placebo for 8 weeks. Food intake at breakfast, lunch, and dinner was directly measured at baseline, week 1, and week 8. For Study 2, Sprague-Dawley rats were fasted for 24 h and subsequently injected intraperitoneally with 0, 1, 10, or 50 μg/kg CrPic. Subsequently, rats were implanted with an indwelling third ventricular cannula. Following recovery, 0, 0.4, 4, or 40 ng of CrPic was injected directly into the brain via the intracerebroventricular cannula, and spontaneous 24-h food intake was measured. Results Study 1 demonstrated that CrPic, as compared to placebo, reduced food intake (P < 0.0001), hunger levels (P < 0.05), and fat cravings (P < 0.0001) and tended to decrease body weight (P = 0.08). In study 2, intraperitoneal administration resulted in a subtle decrease in food intake at only the highest dose (P = 0.03). However, when administered centrally, CrPic dose-dependently decreased food intake (P < 0.05). Conclusions These data suggest CrPic has a role in food intake regulation, which may be mediated by a direct effect on the brain. PMID:18715218

46 CFR 13.309 - Eligibility: Cargo course.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Eligibility: Cargo course. 13.309 Section 13.309... TANKERMEN Requirements for âTankerman-PIC (Barge)â Endorsement § 13.309 Eligibility: Cargo course. Each... a course in DL or LG appropriate for tank barges and for Tankerman-PIC or Tankerman-PIC (Barge), and...

46 CFR 13.309 - Eligibility: Cargo course.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Eligibility: Cargo course. 13.309 Section 13.309... TANKERMEN Requirements for âTankerman-PIC (Barge)â Endorsement § 13.309 Eligibility: Cargo course. Each... a course in DL or LG appropriate for tank barges and for Tankerman-PIC or Tankerman-PIC (Barge), and...

46 CFR 13.309 - Eligibility: Cargo course.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Eligibility: Cargo course. 13.309 Section 13.309... TANKERMEN Requirements for âTankerman-PIC (Barge)â Endorsement § 13.309 Eligibility: Cargo course. Each... a course in DL or LG appropriate for tank barges and for Tankerman-PIC or Tankerman-PIC (Barge), and...

46 CFR 13.309 - Eligibility: Cargo course.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Eligibility: Cargo course. 13.309 Section 13.309... TANKERMEN Requirements for âTankerman-PIC (Barge)â Endorsement § 13.309 Eligibility: Cargo course. Each... a course in DL or LG appropriate for tank barges and for Tankerman-PIC or Tankerman-PIC (Barge), and...

Chemical properties and biotoxicity of several chromium picolinate derivatives.

PubMed

Liu, Bin; Liu, Yanfei; Chai, Jie; Hu, Xiangquan; Wu, Duoming; Yang, Binsheng

2016-11-01

As a man-made additive, chromium picolinate Cr(pic) 3 has become a popular dietary supplement worldwide. In this paper Cr(pic) 3 and its new derivatives Cr(6-CH 3 -pic) 3 (1), [Cr(6-NH 2 -pic) 2 (H 2 O) 2 ]NO 3 (2) and Cr(3-NH 2 -pic) 3 (3) were synthesized, and complexes 1 and 2 were characterized by X-ray crystal structure (where pic=2-carboxypyridine). The relationship between the chemical properties and biotoxicity of these complexes was fully discussed: (1) The dynamics stability of chromium picolinate complexes mainly depends on the CrN bonds length. (2) There is a positive correlation between the dynamics stability, electrochemical potentials and generation of reactive oxygen species through Fenton-like reaction. (3) However, no biological toxicity was observed through MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and sub-chronic oral toxicity study for these chromium picolinate compounds. Together, our findings establish a framework for understanding the structure-property-toxicity relationships of the chromium picolinate complexes. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects of chromium picolinate on the viability of chick embryo fibroblast.

PubMed

Bai, Y; Zhao, X; Qi, C; Wang, L; Cheng, Z; Liu, M; Liu, J; Yang, D; Wang, S; Chai, T

2014-04-01

Chromium picolinate (CrPic), which is used as a nutritional supplement and to treat type 2 diabetes, has gained much attention because of its cytotoxicity. This study evaluated the effects of CrPic on the viability of the chick embryo fibroblast (CEF) using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, morphological detection, and flow cytometry. The results show that lower concentrations of CrPic (8 and 16 μM) did not damage CEF viability (p > 0.05). However, higher CrPic concentrations (400 and 600 μM) indicated a highly significant effect on the production of intracellular reactive oxygen species, alteration of mitochondrial membrane potential, intracellular calcium ion concentration, and the apoptosis rate (p < 0.01), contrary to lower CrPic concentrations (8 and 16 μM) and control group. Moreover, apoptotic morphological changes induced by these processes in CEF were confirmed using Hoechst 33258 staining. Cell death induced by higher concentrations of CrPic was caused by an apoptotic and a necrotic mechanism, whereas the main mechanism of oxidative stress-induced mitochondrial dysfunction was apoptotic death.

Development of the automated bunker door by using a microcontroller-system

NASA Astrophysics Data System (ADS)

Ahmad, M. A.; Leo, K. W.; Mohamad, G. H. P.; Ahmad, A.; Hashim, S. A.; Chulan, R. M.; Baijan, A. H.

2018-01-01

The new low energy electron beam accelerator bunker was designed and built locally to allocate a 500 keV electron beam accelerator at Block 43T in Malaysian Nuclear Agency. This bunker is equipped with a locally made radiation shielding door of 10 tons. Originally, this door is moving manually by a wheel and fitted with a gear system. However, it is still heavy and need longer time to operate it manually. To overcome those issues, a new automated control system has been designed and developed. In this paper, the complete steps and design of automated control system based on the microcontroller (PIC16F84A) is described.

Role of liver fatty acid binding protein in hepatocellular injury: effect of CrPic treatment.

PubMed

Fan, Weijiang; Chen, Kun; Zheng, Guoqiang; Wang, Wenhang; Teng, Anguo; Liu, Anjun; Ming, Dongfeng; Yan, Peng

2013-07-01

This study was designed to investigate the molecular mechanisms of chromium picolinate (CrPic, Fig. 1) hepatoprotective activity from alloxan-induced hepatic injury. Diabetes is induced by alloxan-treatment concurrently with the hepatic injury in mice. In this study, we investigate the protective effect of CrPic treatment in hepatic injury and the signal role of liver fatty acid binding protein in early hepatocellular injury diagnostics. In this study, alanine aminotransferase (ALT; EC 2.6.1.2) and aspartate aminotransferase (AST; EC 2.6.1.1) levels in the alloxan group were higher 71% and 50%, respectively, than those of the control group (ALT: 14.51±0.74; AST: 22.60±0.69). The AST and ALT levels in CrPic group were of minimal difference compared to the control groups. Here, CrPic exhibited amelioration alloxan induced oxidative stress in mouse livers. A significant increase in liver fatty acid-binding protein (L-FABP) was observed, which indicates increased fatty acid utilization in liver tissue [1]. In this study, the mRNA levels of L-FABP increased in both the control (1.1 fold) and CrPic (0.78 fold) groups compared the alloxan group. These findings suggest that hepatic injury may be prevented by CrPic, and is a potential target for use in the treatment of early hepatic injury. Copyright © 2013 Elsevier Inc. All rights reserved.

Evaluation of the Parent-Implemented Communication Strategies (PiCS) Project Using the Multiattribute Utility (MAU) Approach

ERIC Educational Resources Information Center

Stoner, Julia B.; Meadan, Hedda; Angell, Maureen E.; Daczewitz, Marcus

2012-01-01

We conducted a multiattribute utility (MAU) evaluation to assess the Parent-Implemented Communication Strategies (PiCS) project which was funded by the Institute of Education Sciences (IES). In the PiCS project parents of young children with developmental disabilities are trained and coached in their homes on naturalistic and visual teaching…

Apar-T: code, validation, and physical interpretation of particle-in-cell results

NASA Astrophysics Data System (ADS)

Melzani, Mickaël; Winisdoerffer, Christophe; Walder, Rolf; Folini, Doris; Favre, Jean M.; Krastanov, Stefan; Messmer, Peter

2013-10-01

We present the parallel particle-in-cell (PIC) code Apar-T and, more importantly, address the fundamental question of the relations between the PIC model, the Vlasov-Maxwell theory, and real plasmas. First, we present four validation tests: spectra from simulations of thermal plasmas, linear growth rates of the relativistic tearing instability and of the filamentation instability, and nonlinear filamentation merging phase. For the filamentation instability we show that the effective growth rates measured on the total energy can differ by more than 50% from the linear cold predictions and from the fastest modes of the simulation. We link these discrepancies to the superparticle number per cell and to the level of field fluctuations. Second, we detail a new method for initial loading of Maxwell-Jüttner particle distributions with relativistic bulk velocity and relativistic temperature, and explain why the traditional method with individual particle boosting fails. The formulation of the relativistic Harris equilibrium is generalized to arbitrary temperature and mass ratios. Both are required for the tearing instability setup. Third, we turn to the key point of this paper and scrutinize the question of what description of (weakly coupled) physical plasmas is obtained by PIC models. These models rely on two building blocks: coarse-graining, i.e., grouping of the order of p ~ 1010 real particles into a single computer superparticle, and field storage on a grid with its subsequent finite superparticle size. We introduce the notion of coarse-graining dependent quantities, i.e., quantities depending on p. They derive from the PIC plasma parameter ΛPIC, which we show to behave as ΛPIC ∝ 1/p. We explore two important implications. One is that PIC collision- and fluctuation-induced thermalization times are expected to scale with the number of superparticles per grid cell, and thus to be a factor p ~ 1010 smaller than in real plasmas, a fact that we confirm with simulations. The other is that the level of electric field fluctuations scales as 1/ΛPIC ∝ p. We provide a corresponding exact expression, taking into account the finite superparticle size. We confirm both expectations with simulations. Fourth, we compare the Vlasov-Maxwell theory, often used for code benchmarking, to the PIC model. The former describes a phase-space fluid with Λ = + ∞ and no correlations, while the PIC plasma features a small Λ and a high level of correlations when compared to a real plasma. These differences have to be kept in mind when interpreting and validating PIC results against the Vlasov-Maxwell theory and when modeling real physical plasmas.

Water column profiles of particulate inorganic carbon in the northeast subarctic Pacific Ocean

NASA Astrophysics Data System (ADS)

Sutton, J. N.; Bishop, J. K.; Martinez, E. J.; Weiss, G. A.; Weiss, A.; Derr, A.; Strubhar, W.; Robert, M.; Wood, T.

2013-12-01

High resolution and real-time measurement of particulate inorganic carbon (PIC) content in seawater is necessary to improve our spatial and temporal understanding of marine carbon flux and the possible effects of ocean acidification on the biological pump. On four occasions since August 2012, we have mapped PIC distribution from surface to bottom at 26 stations along the IOS-Canada Line P transect from western Vancouver Island, BC, Canada to Ocean Station PAPA, 50N 145W using a prototype (PIC001) and a near-commercial quality (PIC008) optical birefringence sensor. The sensors are highly modified 6000m-rated WETLabs C-star transmissometers, which use a polarized laser beam and a cross-polarized receiver to measure photons emitted after passing through birefringent solids. At major stations along Line P (P2, P4, P8, P12, P16, P20, P26), one-liter rosette-collected calibration water samples were filtered through 0.45 μm Supor filters using a small-volume direct filtration system. These samples were analysed for acid-leachable particulate elements (with emphasis on Ca, Na, and Mg) by inductively coupled plasma mass spectrometry (ICPMS). ICPMS PIC was calculated as residual Ca after correction for seawater Ca using Na data. Here we report results for late summer (Aug. 2012) and winter (Feb. 2013). As expected, high levels of PIC (> 100 nmol L-1 to > 2000 nmol L-1) were found in surface waters but rapidly declined at depths greater than 200m and increased again in the nepheloid layer (>50 nmol L-1). Striking seasonal differences in PIC content and PIC profile shape were observed particularly at near shore stations P2, P4, P8 and P12. The results from this research, including sensor evolution and calibration performance, will be presented.

Effects of Chromium Picolinate on Vascular Reactivity and Cardiac Ischemia Reperfusion Injury in Spontaneously Hypertensive Rats

PubMed Central

Abebe, Worku; Liu, Jun Yao; Wimborne, Hereward; Mozaffari, Mahmood S.

2013-01-01

Chromium picolinate [Cr(pic)3] is a nutritional supplement widely promoted to exert beneficial metabolic effects in patients with type 2 diabetes/impaired glucose tolerance. Frequent comorbidities in these individuals include systemic hypertension, abnormal vascular function and ischemic heart disease but information on effects of the supplement on these aspects is sparse. Utilizing male spontaneously hypertensive rats (SHR), we examined potential impact of Cr(pic)3 on blood pressure, vascular reactivity and myocardial ischemia reperfusion injury (IRI). Dietary Cr(pic)3 supplementation (as 10 mg chromium/kg diet for 6 weeks) did not affect blood pressure of the SHR. Also, neither norepinephrine (NE) and potassium chloride (KCl)-induced contractility nor sodium nitroprusside (SNP)-induced relaxation of aortic smooth muscle from the SHR was altered by Cr(pic)3 treatment. However, Cr(pic)3 augmented endothelium-dependent relaxation of aortas, produced by acetylcholine (ACh), and this effect was abolished by N-nitro-L-arginine methyl ester (L-NAME) suggesting induction of nitric oxide (NO) production/release. Treatment with Cr(pic)3 did not affect baseline coronary flow rate and rate-pressure-product (RPP) or infarct size following regional IRI. Nonetheless, Cr(pic)3 treatment was associated with improved coronary flow and recovery of myocardial contractility and relaxation following ischemia reperfusion insult. In conclusion, dietary Cr(pic)3 treatment of SHR neither alters blood pressure nor vascular smooth muscle reactivity, but causes enhancement of endothelium-dependent vasorelaxation associated with NO production/release. Additionally, while the treatment does not affect infarct size, it improves functional recovery of the viable portion of the myocardium following IRI. PMID:20885007

Effects of chromium picolinate on vascular reactivity and cardiac ischemia-reperfusion injury in spontaneously hypertensive rats.

PubMed

Abebe, Worku; Liu, Jun Yao; Wimborne, Hereward; Mozaffari, Mahmood S

2010-01-01

Chromium picolinate [Cr(pic)(3)] is a nutritional supplement widely promoted to exert beneficial metabolic effects in patients with type 2 diabetes/impaired glucose tolerance. Frequent comorbidities in these individuals include systemic hypertension, abnormal vascular function and ischemic heart disease, but information on the effects of the supplement on these aspects is sparse. Utilizing male spontaneously hypertensive rats (SHR), we examined the potential impact of Cr(pic)(3) on blood pressure, vascular reactivity and myocardial ischemia-reperfusion injury (IRI). Dietary Cr(pic)(3) supplementation (as 10 mg chromium/kg diet for six weeks) did not affect blood pressure of the SHR. Also, neither norepinephrine (NE) and potassium chloride (KCl)-induced contractility nor sodium nitroprusside (SNP)-induced relaxation of aortic smooth muscle from the SHR was altered by Cr(pic)(3) treatment. However, Cr(pic)(3) augmented endothelium-dependent relaxation of aortas, produced by acetylcholine (ACh), and this effect was abolished by N-nitro-L-arginine methyl ester (L-NAME), suggesting induction of nitric oxide (NO) production/release. Treatment with Cr(pic)(3) did not affect baseline coronary flow rate and rate-pressure-product (RPP) or infarct size following regional IRI. Nonetheless, Cr(pic)(3) treatment was associated with improved coronary flow and recovery of myocardial contractility and relaxation following ischemia-reperfusion insult. In conclusion, dietary Cr(pic)(3) treatment of SHR alters neither blood pressure nor vascular smooth muscle reactivity but causes enhancement of endothelium-dependent vasorelaxation associated with NO production/release. Additionally, while the treatment does not affect infarct size, it improves functional recovery of the viable portion of the myocardium following IRI.

Stable carbon isotope signals in particulate organic and inorganic carbon of coccolithophores - A numerical model study for Emiliania huxleyi.

PubMed

Holtz, Lena-Maria; Wolf-Gladrow, Dieter; Thoms, Silke

2017-05-07

A recent numerical cell model, which explains observed light and carbonate system effects on particulate organic and inorganic carbon (POC and PIC) production rates under the assumption of internal pH homeostasis, is extended for stable carbon isotopes ( 12 C, 13 C). Aim of the present study is to mechanistically understand the stable carbon isotopic fractionation signal (ε) in POC and PIC and furthermore the vital effect(s) included in measured ε PIC values. The virtual cell is divided into four compartments, for each of which the 12 C as well as the 13 C carbonate system kinetics are implemented. The compartments are connected to each other via trans-membrane fluxes. In contrast to existing carbon fractionation models, the presented model calculates the disequilibrium state for both carbonate systems and for each compartment. It furthermore calculates POC and PIC production rates as well as ε POC and ε PIC as a function of given light conditions and the compositions of the external carbonate system. Measured POC and PIC production rates as well as ε PIC values are reproduced well by the model (comparison with literature data). The observed light effect on ε POC (increase of ε POC with increasing light intensities), however, is not reproduced by the basic model set-up, which is solely based on RubisCO fractionation. When extending the latter set-up by assuming that biological fractionation includes further carbon fractionation steps besides the one of RubisCO, the observed light effect on ε POC is also reproduced. By means of the extended model version, four different vital effects that superimpose each other in a real cell can be detected. Finally, we discuss potential limitations of the ε PIC proxy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Copper Import into the Mitochondrial Matrix in Saccharomyces cerevisiae Is Mediated by Pic2, a Mitochondrial Carrier Family Protein*

PubMed Central

Vest, Katherine E.; Leary, Scot C.; Winge, Dennis R.; Cobine, Paul A.

2013-01-01

Saccharomyces cerevisiae must import copper into the mitochondrial matrix for eventual assembly of cytochrome c oxidase. This copper is bound to an anionic fluorescent molecule known as the copper ligand (CuL). Here, we identify for the first time a mitochondrial carrier family protein capable of importing copper into the matrix. In vitro transport of the CuL into the mitochondrial matrix was saturable and temperature-dependent. Strains with a deletion of PIC2 grew poorly on copper-deficient non-fermentable medium supplemented with silver and under respiratory conditions when challenged with a matrix-targeted copper competitor. Mitochondria from pic2Δ cells had lower total mitochondrial copper and exhibited a decreased capacity for copper uptake. Heterologous expression of Pic2 in Lactococcus lactis significantly enhanced CuL transport into these cells. Therefore, we propose a novel role for Pic2 in copper import into mitochondria. PMID:23846699

Copper import into the mitochondrial matrix in Saccharomyces cerevisiae is mediated by Pic2, a mitochondrial carrier family protein.

PubMed

Vest, Katherine E; Leary, Scot C; Winge, Dennis R; Cobine, Paul A

2013-08-16

Saccharomyces cerevisiae must import copper into the mitochondrial matrix for eventual assembly of cytochrome c oxidase. This copper is bound to an anionic fluorescent molecule known as the copper ligand (CuL). Here, we identify for the first time a mitochondrial carrier family protein capable of importing copper into the matrix. In vitro transport of the CuL into the mitochondrial matrix was saturable and temperature-dependent. Strains with a deletion of PIC2 grew poorly on copper-deficient non-fermentable medium supplemented with silver and under respiratory conditions when challenged with a matrix-targeted copper competitor. Mitochondria from pic2Δ cells had lower total mitochondrial copper and exhibited a decreased capacity for copper uptake. Heterologous expression of Pic2 in Lactococcus lactis significantly enhanced CuL transport into these cells. Therefore, we propose a novel role for Pic2 in copper import into mitochondria.

Multirate Particle-in-Cell Time Integration Techniques of Vlasov-Maxwell Equations for Collisionless Kinetic Plasma Simulations

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

Chen, Guangye; Chacon, Luis; Knoll, Dana Alan

2015-07-31

A multi-rate PIC formulation was developed that employs large timesteps for slow field evolution, and small (adaptive) timesteps for particle orbit integrations. Implementation is based on a JFNK solver with nonlinear elimination and moment preconditioning. The approach is free of numerical instabilities (ω peΔt >>1, and Δx >> λ D), and requires many fewer dofs (vs. explicit PIC) for comparable accuracy in challenging problems. Significant gains (vs. conventional explicit PIC) may be possible for large scale simulations. The paper is organized as follows: Vlasov-Maxwell Particle-in-cell (PIC) methods for plasmas; Explicit, semi-implicit, and implicit time integrations; Implicit PIC formulation (Jacobian-Free Newton-Krylovmore » (JFNK) with nonlinear elimination allows different treatments of disparate scales, discrete conservation properties (energy, charge, canonical momentum, etc.)); Some numerical examples; and Summary.« less

Interferometric imaging using Si3N4 photonic integrated circuits for a SPIDER imager.

PubMed

Su, Tiehui; Liu, Guangyao; Badham, Katherine E; Thurman, Samuel T; Kendrick, Richard L; Duncan, Alan; Wuchenich, Danielle; Ogden, Chad; Chriqui, Guy; Feng, Shaoqi; Chun, Jaeyi; Lai, Weicheng; Yoo, S J B

2018-05-14

This paper reports design, fabrication, and experimental demonstration of a silicon nitride photonic integrated circuit (PIC). The PIC is capable of conducting one-dimensional interferometric imaging with twelve baselines near λ = 1100-1600 nm. The PIC consists of twelve waveguide pairs, each leading to a multi-mode interferometer (MMI) that forms broadband interference fringes or each corresponding pair of the waveguides. Then an 18 channel arrayed waveguide grating (AWG) separates the combined signal into 18 signals of different wavelengths. A total of 103 sets of fringes are collected by the detector array at the output of the PIC. We keep the optical path difference (OPD) of each interferometer baseline to within 1 µm to maximize the visibility of the interference measurement. We also constructed a testbed to utilize the PIC for two-dimension complex visibility measurement with various targets. The experiment shows reconstructed images in good agreement with theoretical predictions.

Functional interplay between Mediator and TFIIB in preinitiation complex assembly in relation to promoter architecture

PubMed Central

Eychenne, Thomas; Novikova, Elizaveta; Barrault, Marie-Bénédicte; Alibert, Olivier; Boschiero, Claire; Peixeiro, Nuno; Cornu, David; Redeker, Virginie; Kuras, Laurent; Nicolas, Pierre; Werner, Michel; Soutourina, Julie

2016-01-01

Mediator is a large coregulator complex conserved from yeast to humans and involved in many human diseases, including cancers. Together with general transcription factors, it stimulates preinitiation complex (PIC) formation and activates RNA polymerase II (Pol II) transcription. In this study, we analyzed how Mediator acts in PIC assembly using in vivo, in vitro, and in silico approaches. We revealed an essential function of the Mediator middle module exerted through its Med10 subunit, implicating a key interaction between Mediator and TFIIB. We showed that this Mediator–TFIIB link has a global role on PIC assembly genome-wide. Moreover, the amplitude of Mediator's effect on PIC formation is gene-dependent and is related to the promoter architecture in terms of TATA elements, nucleosome occupancy, and dynamics. This study thus provides mechanistic insights into the coordinated function of Mediator and TFIIB in PIC assembly in different chromatin contexts. PMID:27688401

CLIC4 Moves Into Nucleus to Stabilize Anti-Growth Signal | Center for Cancer Research

Cancer.gov

In cancer, the delicate balance of signaling pathways that control cell growth and function is disrupted. One signaling pathway commonly altered in cancer is the TGF-beta pathway. TGF-beta significantly inhibits growth of normal cells, particularly epithelial cells. Many cancer cells have developed ways to bypass one or more steps of this pathway in order to achieve uncontrolled growth.

CLIC4 Moves Into Nucleus to Stabilize Anti-Growth Signal | Center for Cancer Research

Cancer.gov

In cancer, the delicate balance of signaling pathways that control cell growth and function is disrupted. One signaling pathway commonly altered in cancer is the TGF-beta pathway. TGF-beta significantly inhibits growth of normal cells, particularly epithelial cells. Many cancer cells have developed ways to bypass one or more steps of this pathway in order to achieve

Planning, Management and Evaluation: Realizing PIC Potential. Private Industry Council Guide. Working Draft.

ERIC Educational Resources Information Center

National Alliance of Business, Inc., Washington, DC.

This Planning, Management, and Evaluation (PME) guide was developed by the National Alliance of Business as part of its program of management assistance for Private Industry Councils (PICs). The guide is a tool which PICs can use to improve their capability to plan, manage, and evaluate the programs which they administer, and to establish locally…

PICs, TECs and LECs: Lessons to Be Learnt from the Differences between the USA Private Industry Councils and Britain's Training and Enterprise Councils.

ERIC Educational Resources Information Center

Bennett, Robert J.

1994-01-01

Comparison of Britain's Training and Enterprise Councils/Local Enterprise Companies with the United States' Private Industry Councils (PICs) shows common problems: inadequate financing, labor market fragmentation, staff turnover, and lack of national strategy. PICs have a clearer mission and greater success in developing partnerships with local…

Private Industry Councils: Examining Their Mission under the Job Training Partnership Act. Special Report Number 35.

ERIC Educational Resources Information Center

National Commission for Employment Policy (DOL), Washington, DC.

A number of findings and recommendations regarding the mission of Private Industry Councils (PICs) under the Job Training Partnership ACT (JTPA) were developed based on information collected in several ways: a focus group of PICs, roundtable discussions held nationwide with staff from nearly 100 PICs in 45 states, and canvasses of more than 200…

Accelerating a Particle-in-Cell Simulation Using a Hybrid Counting Sort

NASA Astrophysics Data System (ADS)

Bowers, K. J.

2001-11-01

In this article, performance limitations of the particle advance in a particle-in-cell (PIC) simulation are discussed. It is shown that the memory subsystem and cache-thrashing severely limit the speed of such simulations. Methods to implement a PIC simulation under such conditions are explored. An algorithm based on a counting sort is developed which effectively eliminates PIC simulation cache thrashing. Sustained performance gains of 40 to 70 percent are measured on commodity workstations for a minimal 2d2v electrostatic PIC simulation. More complete simulations are expected to have even better results as larger simulations are usually even more memory subsystem limited.

A spectral, quasi-cylindrical and dispersion-free Particle-In-Cell algorithm

DOE PAGES

Lehe, Remi; Kirchen, Manuel; Andriyash, Igor A.; ...

2016-02-17

We propose a spectral Particle-In-Cell (PIC) algorithm that is based on the combination of a Hankel transform and a Fourier transform. For physical problems that have close-to-cylindrical symmetry, this algorithm can be much faster than full 3D PIC algorithms. In addition, unlike standard finite-difference PIC codes, the proposed algorithm is free of spurious numerical dispersion, in vacuum. This algorithm is benchmarked in several situations that are of interest for laser-plasma interactions. These benchmarks show that it avoids a number of numerical artifacts, that would otherwise affect the physics in a standard PIC algorithm - including the zero-order numerical Cherenkov effect.

Library services and user satisfaction in developing countries: a case study.

PubMed

Mairaj, Muhammad Ijaz; Naseer, Mirza Muhammad

2013-12-01

Punjab Institute of Cardiology (PIC) is a recognised teaching hospital for cardiac care in the Punjab province of Pakistan. PIC has established a library to fulfil the research and information needs of health care professionals. This study aims to evaluate the satisfaction of users with the services of PIC library. A purposive sample of 15 health care professionals was selected. A semistructured interview technique based on an interview guide was used for collection of data. The data were qualitatively analysed using a thematic approach. Users of PIC library were satisfied with the library collection, organisation, reference and circulation services, staff attitudes, cooling and heating. They were concerned about library space, hours, furniture and environment, and suggested more availability of electronic library services, newer collections, better Internet access and comfortable furniture. The study proved useful to investigate users' satisfaction with the services of PIC library. It concludes that the PIC library should maintain and strengthen the services with which users are satisfied, and improve those about which they are concerned. The study will be useful to libraries in other developing countries for improvement in their services. © 2013 The authors. Health Information and Libraries Journal © 2013 Health Libraries Group.

Chromium picolinate supplementation in women: effects on body weight, composition, and iron status.

PubMed

Lukaski, Henry C; Siders, William A; Penland, James G

2007-03-01

This study tested the hypothesis that supplementation of chromium picolinate (CrPic), 200 microg Cr/d, compared with an equivalent amount of picolinic acid (1720 microg) in CrPic and placebo, decreases body weight, alters body composition, and reduces iron status of women fed diets of constant energy and nutrients. We fed 83 women nutritionally balanced diets, used anthropometry and dual x-ray absorptiometry to assess body composition, and measured serum and urinary Cr and biochemical indicators of iron status before and serially every 4 wk for 12 wk in a double-blind, randomized trial. CrPic supplementation increased (P < 0.0001) serum Cr concentration and urinary Cr excretion compared with picolinic acid and placebo. CrPic did not affect body weight or fat, although all groups lost (P < 0.05) weight and fat; it did not affect fat-free, mineral-free mass or measurements of iron status. Under conditions of controlled energy intake, CrPic supplementation of women did not independently influence body weight or composition or iron status. Thus, claims that supplementation of 200 microg of Cr as CrPic promotes weight loss and body composition changes are not supported.

Chromium picolinate induced apoptosis of lymphocytes and the signaling mechanisms thereof

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

Jana, Mahadevan; Rajaram, Anantanarayanan; Rajaram, Rama

2009-06-15

Cr(III)(picolinate){sub 3} [Cr(III)(pic){sub 3}] is currently used as a nutritional supplement and for treating Type-2 diabetes. The effect of Cr(III)(pic){sub 3} uptake in peripheral blood lymphocytes is investigated in this study. From the cytotoxicity data, DNA fragmentation pattern, Annexin V staining, TUNEL positivity and the ultrastructural characteristics such as chromatin condensation and formation of apoptotic bodies, it is clear that Cr(III)(pic){sub 3} induces a concentration dependent apoptosis. It is shown that reactive oxygen species (ROS) produced by treatment with Cr(III)(pic){sub 3} leads to apoptosis, since we find that pretreatment with N-acetyl cysteine inhibits the process. Using Western blotting technique andmore » fluorescence measurements, the downstream signaling molecules have also been identified. Cr(III)(pic){sub 3} treatment leads to collapse of the mitochondrial membrane potential, Bax expression, increase in cytosolic cytochrome c content and active caspase-3 and DNA fragmentation and all these manifestations are reduced by pretreating the lymphocytes with N-acetyl cysteine. Thus, it is shown that Cr(III)(pic){sub 3} is cytotoxic to lymphocytes with ROS and mitochondrial events playing a role in bringing about apoptosis.« less

Parallel Higher-order Finite Element Method for Accurate Field Computations in Wakefield and PIC Simulations

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

Candel, A.; Kabel, A.; Lee, L.

Over the past years, SLAC's Advanced Computations Department (ACD), under SciDAC sponsorship, has developed a suite of 3D (2D) parallel higher-order finite element (FE) codes, T3P (T2P) and Pic3P (Pic2P), aimed at accurate, large-scale simulation of wakefields and particle-field interactions in radio-frequency (RF) cavities of complex shape. The codes are built on the FE infrastructure that supports SLAC's frequency domain codes, Omega3P and S3P, to utilize conformal tetrahedral (triangular)meshes, higher-order basis functions and quadratic geometry approximation. For time integration, they adopt an unconditionally stable implicit scheme. Pic3P (Pic2P) extends T3P (T2P) to treat charged-particle dynamics self-consistently using the PIC (particle-in-cell)more » approach, the first such implementation on a conformal, unstructured grid using Whitney basis functions. Examples from applications to the International Linear Collider (ILC), Positron Electron Project-II (PEP-II), Linac Coherent Light Source (LCLS) and other accelerators will be presented to compare the accuracy and computational efficiency of these codes versus their counterparts using structured grids.« less

Characterization of punctate inner choroidopathy using enhanced depth imaging optical coherence tomography.

PubMed

Zarranz-Ventura, Javier; Sim, Dawn A; Keane, Pearse A; Patel, Praveen J; Westcott, Mark C; Lee, Richard W; Tufail, Adnan; Pavesio, Carlos E

2014-09-01

To perform qualitative and quantitative analyses of retinal and choroidal morphology in patients with punctate inner choroidopathy (PIC) using enhanced depth imaging optical coherence tomography (EDI-OCT). Cross-sectional, consecutive series. A total of 2242 patients attending 2 tertiary referral uveitis clinics at Moorfields Eye Hospital were screened; 46 patients with PIC diagnosis were identified, and 35 eyes (35 patients) had clinically inactive PIC had EDI-OCT images that met the inclusion criteria. Punctate inner choroidopathy lesions were qualitatively assessed for retinal features, such as (1) focal elevation of the retinal pigment epithelium (RPE), (2) focal atrophy of the outer retina/RPE, and (3) presence of sub-RPE hyperreflective deposits and choroidal features: (a) presence of focal hyperreflective dots in the inner choroid and (b) focal thinning of the choroid adjacent to PIC lesions. Quantitative analyses of the retina, choroid, and choroidal sublayers were performed, and associations with clinical and demographic data were examined. Prevalence of each lesion pattern and thickness of retinal and choroidal layers. A total of 90 discrete PIC lesions were captured; 46.6% of PIC lesions consisted of focal atrophy of the outer retina and RPE; 34.4% consisted of sub-RPE hyperreflective deposits; and 18.8% consisted of localized RPE elevation with underlying hyporeflective space. Focal hyperreflective dots were seen in the inner choroid of 68.5% of patients, with 17.1% of eyes presenting focal choroidal thinning underlying PIC lesions. By excluding high myopes, patients with "atypical" PIC had reduced retinal thickness compared with patients with "typical" PIC (246.65±30.2 vs. 270.05±24.6 μm; P = 0.04), and greater disease duration was associated with decreases in retinal thickness (r = -0.53; P = 0.01). A significant correlation was observed between best-corrected visual acuity and foveal retinal thickness (r = -0.40; P = 0.03). In a large series of patients with clinically inactive PIC, one fifth of the lesions analyzed revealed RPE elevation with underlying hyporeflective space, described before as a sign of activity and suggesting subclinical inflammation. Retinal thickness seems to be associated with disease type and duration of disease in non-highly myopic eyes. Improved visualization of the inner choroid using EDI-OCT may allow noninvasive assessment of inflammatory status. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Body mass index is a practical preoperative nutritional index for postoperative infectious complications after intestinal resection in patients with Crohn's disease

PubMed Central

Zhu, Yibin; Zhou, Wei; Qi, Weilin; Liu, Wei; Chen, Mingyu; Zhu, Hepan; Xiang, Jianjian; Xie, Qingwen; Chen, Pengpeng

2017-01-01

Abstract The patients with Crohn's disease (CD) are often accompanied with nutritional deficiencies. Compared with other intestinal benign disease, patients with CD have the higher risk of developing postoperative complications following intestinal resection. The aim of this study was to investigate the risk factors for postoperative infectious complications (PICs) after intestinal resection for CD, as well as search a practical preoperative nutritional index for PICs in patients with CD. A total of 122 patients who underwent intestinal resection for CD during 2011 to 2015 were retrospectively analyzed. After operation, 28 (22.95%) patients experienced PICs. Compared with the non-PICs group, the patients with PICs have the lower preoperative body mass index (BMI) (16.96 ± 2.33 vs 19.53 ± 2.49 kg/m2, P < .001), lower albumin (ALB) (33.64 ± 5.58 vs 36.55 ± 5.69 g/L, P = .013), higher C-reactive protein (CRP) level (30.44 ± 37.06 vs 15.99 ± 33.30 mg/L, P = .052), and longer hospital stay (22.64 ± 9.93 vs 8.90 ± 4.32 days, P < .001). By analyzing the receiver-operating characteristic (ROC) curve, BMI have better value in predicting the occurrence of PICs than ALB. The areas under the ROC curves of BMI for PICs was 0.784 (95% confidence interval 0.690–0.878, P < .001) with an optimal diagnostic cut-off value of 17.5 kg/m2. In the univariate and multivariate analysis, BMI < 17.5 kg/m2 (P = .001), ALB < 33.6 g/L (P = .024), CRP ≥ 10 mg/L (P = .026) were risk factors for PICs. Patients with a lower preoperative BMI (BMI < 17.5 kg/m2) had a 7.35 times greater risk of PICs. Therefore, preoperative BMI could be regarded as a practical preoperative nutritional index for evaluating the nutritional preparation sufficiency before CD operations. Preoperative treatment with the aim of reducing CRP level and improving the patient's nutritional status may be helpful to reduce the rate of PICs. PMID:28591060

Impact of the Quality of Bowel Cleansing on the Efficacy of Colonic Cancer Screening: A Prospective, Randomized, Blinded Study

PubMed Central

2015-01-01

Objectives Efficacy of two low volume bowel cleansing preparations, polyethylene glycol plus ascorbate (PEG+Asc) and sodium picosulfate/magnesium citrate (NaPic/MgCit), were compared for polyp and adenoma detection rate (PDR and ADR) and overall cleansing ability. Primary endpoint was PDR (the number of patients with ≥1 polypoid or flat lesion recorded by the colonoscopist). Methods Diagnostic, surveillance or screening colonoscopy patients were enrolled into this investigator-blinded, multi-center Phase IV study and randomized 1:1 to receive PEG+Asc (administered the evening before and the morning of colonoscopy, per label) or NaPic/MgCit (administered in the morning and afternoon the day before colonoscopy, per label). The blinded colonoscopist documented any lesion and assessed cleansing quality (Harefield Cleansing Scale). Results Of 394 patients who completed the study, 393 (PEG+Asc, N=200; NaPic/MgCit, N=193) had a colonoscopy. Overall PDR for PEG+Asc versus NaPic/MgCit was 51.5% versus 44.0%, p=0.139. PDR and ADR on the right side of the bowel were significantly higher with PEG+Asc versus NaPic/MgCit (PDR: 56[28.0%] versus 32[16.6%], p=0.007; ADR: 42[21.0%] versus 23[11.9%], p=0.015), as was detection of flat lesions (43[21.5%] versus 25[13.0%], p=0.025). Cleansing quality was better with PEG+Asc than NaPic/MgCit (98.5% versus 57.5% considered successful cleansing). Overall, there were 132 treatment-emergent adverse events (93 versus 39 for PEG+Asc and NaPic/MgCit, respectively). These were mainly mild abdominal symptoms, all of which were reported for higher proportions of patients in the PEG+Asc than NaPic/MgCit group. Twice as many patients in the NaPic/MgCit versus the PEG+Asc group reported tolerance of cleansing solution as ‘very good’. Conclusions Compared with NaPic/MgCit, PEG+Asc may be more efficacious for overall cleansing ability, and subsequent detection of right-sided and flat lesions. This is likely attributable to the different administration schedules of the two bowel cleansing preparations, which may positively impact the detection and prevention of colorectal cancer, thereby improving mortality rates. Trial Registration ClinicalTrials.gov NCT01689792. PMID:25950434

Biodistribution of charged F(ab')2 photoimmunoconjugates in a xenograft model of ovarian cancer.

PubMed

Duska, L R; Hamblin, M R; Bamberg, M P; Hasan, T

1997-01-01

The effect of charge modification of photoimmunoconjugates (PICs) on their biodistribution in a xenograft model of ovarian cancer was investigated. Chlorin(e6)c(e6) was attached site specifically to the F(ab')2 fragment of the murine monoclonal antibody OC125, directed against human ovarian cancer cells, via poly-1-lysine linkers carrying cationic or anionic charges. Preservation of immunoreactivity was checked by enzyme-linked immunosorbent assay (ELISA). PICs were radiolabelled with 125I and compared with non-specific rabbit IgG PICs after intraperitoneal (i.p.) injection into nude mice. Samples were taken from normal organs and tumour at 3 h and 24 h. Tumour to normal 125I ratios showed that the cationic OC125F(ab')2 PIC had the highest tumour selectivity. Ratios for c(e6) were uniformly higher than for 125I, indicating that c(e6) became separated from 125I. OC125F(ab')2 gave highest tissue values of 125I, followed by cationic OC125F(ab')2 PIC; other species were much lower. The amounts of c(e6) delivered per gram of tumour were much higher for cationic OC125F(ab')2 PIC than for other species. The results indicate that cationic charge stimulates the endocytosis and lysosomal degradation of the OC125F(ab')2-pl-c(e6) that has bound to the i.p. tumour. Positively charged PICs may have applications in the i.p. photoimmunotherapy of minimal residual ovarian cancer.

Insulin receptors and downstream substrates associate with membrane microdomains after treatment with insulin or chromium(III) picolinate.

PubMed

Al-Qatati, Abeer; Winter, Peter W; Wolf-Ringwall, Amber L; Chatterjee, Pabitra B; Van Orden, Alan K; Crans, Debbie C; Roess, Deborah A; Barisas, B George

2012-04-01

We have examined the association of insulin receptors (IR) and downstream signaling molecules with membrane microdomains in rat basophilic leukemia (RBL-2H3) cells following treatment with insulin or tris(2-pyridinecarbxylato)chromium(III) (Cr(pic)(3)). Single-particle tracking demonstrated that individual IR on these cells exhibited reduced lateral diffusion and increased confinement within 100 nm-scale membrane compartments after treatment with either 200 nM insulin or 10 μM Cr(pic)(3). These treatments also increased the association of native IR, phosphorylated insulin receptor substrate 1 and phosphorylated AKT with detergent-resistant membrane microdomains of characteristically high buoyancy. Confocal fluorescence microscopic imaging of Di-4-ANEPPDHQ labeled RBL-2H3 cells also showed that plasma membrane lipid order decreased following treatment with Cr(pic)(3) but was not altered by insulin treatment. Fluorescence correlation spectroscopy demonstrated that Cr(pic)(3) did not affect IR cell-surface density or compete with insulin for available binding sites. Finally, Fourier transform infrared spectroscopy indicated that Cr(pic)(3) likely associates with the lipid interface in reverse-micelle model membranes. Taken together, these results suggest that activation of IR signaling in a cellular model system by both insulin and Cr(pic)(3) involves retention of IR in specialized nanometer-scale membrane microdomains but that the insulin-like effects of Cr(pic)(3) are due to changes in membrane lipid order rather than to direct interactions with IR. © Springer Science+Business Media, LLC 2011

Chromium picolinate inhibits resistin secretion in insulin-resistant 3T3-L1 adipocytes via activation of amp-activated protein kinase.

PubMed

Wang, Yi-Qun; Dong, Yi; Yao, Ming-Hui

2009-08-01

1. Chromium picolinate (CrPic) has been recommended as an alternative therapeutic regimen for Type 2 diabetes mellitus (T2DM). However, the molecular mechanism underlying the action of CrPic is poorly understood. 2. Using normal and insulin-resistant 3T3-L1 adipocytes, we examined the effects of CrPic on the gene transcription and secretion of adiponectin and resistin. In addition, using immunoblotting, ELISA and real-time reverse transcription-polymerase chain reaction (RT-PCR), we investigated the effects of 10 nmol/L CrPic for 24 h on AMP-activated protein kinase (AMPK) to determine whether this pathway contributed to the regulation of adiponectin and resistin expression and secretion. 3. Chromium picolinate did not modulate the expression of adiponectin and resistin; however, it did significantly inhibit the secretion of resistin, but not adiponectin, by normal and insulin-resistant 3T3-L1 adipocytes in vitro. Furthermore, although CrPic markedly elevated levels of phosphorylated AMPK and acetyl CoA carboxylase in 3T3-L1 adipocytes, it had no effect on the levels of AMPK alpha-1 and alpha-2 mRNA transcripts. Importantly, inhibition of AMPK by 2 h pretreatment of cells with 20 micromol/L compound C completely abolished the CrPic-induced suppression of resistin secretion. 4. In conclusion, the data suggest that CrPic inhibits resistin secretion via activation of AMPK in normal and insulin-resistant 3T3-L1 adipocytes.

Skeletal muscle-derived interstitial progenitor cells (PICs) display stem cell properties, being clonogenic, self-renewing, and multi-potent in vitro and in vivo.

PubMed

Cottle, Beverley J; Lewis, Fiona C; Shone, Victoria; Ellison-Hughes, Georgina M

2017-07-04

The development of cellular therapies to treat muscle wastage with disease or age is paramount. Resident muscle satellite cells are not currently regarded as a viable cell source due to their limited migration and growth capability ex vivo. This study investigated the potential of muscle-derived PW1 + /Pax7 - interstitial progenitor cells (PICs) as a source of tissue-specific stem/progenitor cells with stem cell properties and multipotency. Sca-1 + /PW1 + PICs were identified on tissue sections from hind limb muscle of 21-day-old mice, isolated by magnetic-activated cell sorting (MACS) technology and their phenotype and characteristics assessed over time in culture. Green fluorescent protein (GFP)-labelled PICs were used to determine multipotency in vivo in a tumour formation assay. Isolated PICs expressed markers of pluripotency (Oct3/4, Sox2, and Nanog), were clonogenic, and self-renewing with >60 population doublings, and a population doubling time of 15.8 ± 2.9 h. PICs demonstrated an ability to generate both striated and smooth muscle, whilst also displaying the potential to differentiate into cell types of the three germ layers both in vitro and in vivo. Moreover, PICs did not form tumours in vivo. These findings open new avenues for a variety of solid tissue engineering and regeneration approaches, utilising a single multipotent stem cell type isolated from an easily accessible source such as skeletal muscle.

Measurement of In Vitro Integration Activity of HIV-1 Preintegration Complexes.

PubMed

Balasubramaniam, Muthukumar; Davids, Benem; Addai, Amma B; Pandhare, Jui; Dash, Chandravanu

2017-02-22

HIV-1 envelope proteins engage cognate receptors on the target cell surface, which leads to viral-cell membrane fusion followed by the release of the viral capsid (CA) core into the cytoplasm. Subsequently, the viral Reverse Transcriptase (RT), as part of a namesake nucleoprotein complex termed the Reverse Transcription Complex (RTC), converts the viral single-stranded RNA genome into a double-stranded DNA copy (vDNA). This leads to the biogenesis of another nucleoprotein complex, termed the pre-integration complex (PIC), composed of the vDNA and associated virus proteins and host factors. The PIC-associated viral integrase (IN) orchestrates the integration of the vDNA into the host chromosomal DNA in a temporally and spatially regulated two-step process. First, the IN processes the 3' ends of the vDNA in the cytoplasm and, second, after the PIC traffics to the nucleus, it mediates integration of the processed vDNA into the chromosomal DNA. The PICs isolated from target cells acutely infected with HIV-1 are functional in vitro, as they are competent to integrate the associated vDNA into an exogenously added heterologous target DNA. Such PIC-based in vitro integration assays have significantly contributed to delineating the mechanistic details of retroviral integration and to discovering IN inhibitors. In this report, we elaborate upon an updated HIV-1 PIC assay that employs a nested real-time quantitative Polymerase Chain Reaction (qPCR)-based strategy for measuring the in vitro integration activity of isolated native PICs.

Evaluating CoLiDeS + Pic: The Role of Relevance of Pictures in User Navigation Behaviour

ERIC Educational Resources Information Center

Karanam, Saraschandra; van Oostendorp, Herre; Indurkhya, Bipin

2012-01-01

CoLiDeS + Pic is a cognitive model of web-navigation that incorporates semantic information from pictures into CoLiDeS. In our earlier research, we have demonstrated that by incorporating semantic information from pictures, CoLiDeS + Pic can predict the hyperlinks on the shortest path more frequently, and also with greater information scent,…

Chromium nanoparticle exhibits higher absorption efficiency than chromium picolinate and chromium chloride in Caco-2 cell monolayers.

PubMed

Zha, L-Y; Xu, Z-R; Wang, M-Q; Gu, L-Y

2008-04-01

This study was conducted to determine whether chromium nanoparticle (CrNano) exhibited higher absorption efficiency and possessed unique absorption mechanism in comparison to chromium picolinate (CrPic) and chromium chloride (CrCl(3)), as was postulated by previous reports. Twenty-one-day-old Caco-2 cell monolayers grown on semipermeable membranes in Snapwell tissue culture bichambers were incubated with CrNano, CrPic or CrCl(3) to examine their transport and uptake respectively. In the concentration range of 0.2-20 micromol/l, transport of CrNano, CrPic and CrCl(3) across Caco-2 monolayers both in apical-to-basolateral and basolateral-to-apical direction was concentration-, and time-dependent, and temperature independent. The apparent permeability coefficient (P(app)) of CrNano was between 5.89 and 7.92 x 10(-6) cm/s and that of CrPic and CrCl(3) was between 3.52 and 5.31 x 10(-6) cm/s and between 0.97 and 1.37 x 10(-6) cm/s respectively. Uptake of CrNano, CrPic and CrCl(3) by both apical and basolateral membranes was concentration- and time-dependent. Uptake of CrNano by apical membrane was significantly (p < 0.05) decreased when the incubation temperature was reduced from 37 degrees C to 4 degrees C. The transport efficiency of CrNano, CrPic and CrCl(3) after incubation for 120 min at 37 degrees C was 15.83% +/- 0.76%, 9.08% +/- 0.25% and 2.11% +/- 0.53% respectively. The uptake efficiency of CrNano, CrPic and CrCl(3) was 10.08% +/- 0.76%, 4.73% +/- 0.60% and 0.88% +/- 0.08% respectively. It was concluded that the epithelial transport of CrNano, CrPic and CrCl(3) across the Caco-2 cell monolayers was mainly via passive transport pathways. In addition, CrNano exhibited considerably higher absorption efficiency than both CrPic and CrCl(3) in Caco-2 cell monolayers.

Temperature affects the morphology and calcification of Emiliania huxleyi strains

NASA Astrophysics Data System (ADS)

Rosas-Navarro, Anaid; Langer, Gerald; Ziveri, Patrizia

2016-05-01

The global warming debate has sparked an unprecedented interest in temperature effects on coccolithophores. The calcification response to temperature changes reported in the literature, however, is ambiguous. The two main sources of this ambiguity are putatively differences in experimental setup and strain specificity. In this study we therefore compare three strains isolated in the North Pacific under identical experimental conditions. Three strains of Emiliania huxleyi type A were grown under non-limiting nutrient and light conditions, at 10, 15, 20 and 25 °C. All three strains displayed similar growth rate versus temperature relationships, with an optimum at 20-25 °C. Elemental production (particulate inorganic carbon (PIC), particulate organic carbon (POC), total particulate nitrogen (TPN)), coccolith mass, coccolith size, and width of the tube element cycle were positively correlated with temperature over the sub-optimum to optimum temperature range. The correlation between PIC production and coccolith mass/size supports the notion that coccolith mass can be used as a proxy for PIC production in sediment samples. Increasing PIC production was significantly positively correlated with the percentage of incomplete coccoliths in one strain only. Generally, coccoliths were heavier when PIC production was higher. This shows that incompleteness of coccoliths is not due to time shortage at high PIC production. Sub-optimal growth temperatures lead to an increase in the percentage of malformed coccoliths in a strain-specific fashion. Since in total only six strains have been tested thus far, it is presently difficult to say whether sub-optimal temperature is an important factor causing malformations in the field. The most important parameter in biogeochemical terms, the PIC : POC ratio, shows a minimum at optimum growth temperature in all investigated strains. This clarifies the ambiguous picture featuring in the literature, i.e. discrepancies between PIC : POC-temperature relationships reported in different studies using different strains and different experimental setups. In summary, global warming might cause a decline in coccolithophore's PIC contribution to the rain ratio, as well as improved fitness in some genotypes due to fewer coccolith malformations.

The Revised WIPP Passive Institutional Controls Program - A Conceptual Plan - 13145

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

Patterson, Russ; Klein, Thomas; Van Luik, Abraham

2013-07-01

The Department of Energy/Carlsbad Field Office (DOE/CBFO) is responsible for managing all activities related to the disposal of TRU and TRU-mixed waste in the geologic repository, 650 m below the land surface, at WIPP, near Carlsbad, New Mexico. The main function of the Passive Institutional Controls (PIC's) program is to inform future generations of the long-lived radioactive wastes buried beneath their feet in the desert. For the first 100 years after cessation of disposal operations, the rooms are closed and the shafts leading underground sealed, WIPP is mandated by law to institute Active Institutional Controls (AIC's) with fences, gates, andmore » armed guards on patrol. At this same time a plan must be in place of how to warn/inform the future, after the AIC's are gone, of the consequences of intrusion into the geologic repository disposal area. A plan was put into place during the 1990's with records management and storage, awareness triggers, permanent marker design concepts and testing schedules. This work included the thoughts of expert panels and individuals. The plan held up under peer review and met the requirements of the U.S. Environmental Protection Agency (EPA). Today the NEA is coordinating a study called the 'Preservation of Records, Knowledge and Memory (RK and M) Across Generations' to provide the international nuclear waste repository community with a guide on how a nuclear record archive programs should be approached and developed. CBFO is cooperating and participating in this project and will take what knowledge is gained and apply that to the WIPP program. At the same time CBFO is well aware that the EPA and others are expecting DOE to move forward with planning for the future WIPP PIC's program; so a plan will be in place in time for WIPP's closure slated for the early 2030's. The DOE/CBFO WIPP PIC's program in place today meets the regulatory criteria, but complete feasibility of implementation is questionable, and may not be in conformance with the international guidance being developed. International guidance currently under development may suggest that the inter-generational equity principle strives to warn the future, however, in doing so not to unduly burden present generations. Building markers and monuments that are out of proportion to the risk being presented to the future is not in keeping with generational equity. With this in mind the DOE/CBFO is developing conceptual plans for re-evaluating and revising the current WIPP PIC's program. These conceptual plans will suggest scientific and technical work that must be completed to develop a 'new' PICs program that takes the best ideas of the present plan, blended with new ideas from the RK and M project, and proposed alternative permanent markers designs and materials in consideration. (authors)« less

Laser propagation and soliton generation in strongly magnetized plasmas

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

Feng, W.; Li, J. Q.; Kishimoto, Y.

The propagation characteristics of various laser modes with different polarization, as well as the soliton generation in strongly magnetized plasmas are studied numerically through one-dimensional (1D) particle-in-cell (PIC) simulations and analytically by solving the laser wave equation. PIC simulations show that the laser heating efficiency substantially depends on the magnetic field strength, the propagation modes of the laser pulse and their intensities. Generally, large amplitude laser can efficiently heat the plasma with strong magnetic field. Theoretical analyses on the linear propagation of the laser pulse in both under-dense and over-dense magnetized plasmas are well confirmed by the numerical observations. Mostmore » interestingly, it is found that a standing or moving soliton with frequency lower than the laser frequency is generated in certain magnetic field strength and laser intensity range, which can greatly enhance the laser heating efficiency. The range of magnetic field strength for the right-hand circularly polarized (RCP) soliton formation with high and low frequencies is identified by solving the soliton equations including the contribution of ion's motion and the finite temperature effects under the quasi-neutral approximation. In the limit of immobile ions, the RCP soliton tends to be peaked and stronger as the magnetic field increases, while the enhanced soliton becomes broader as the temperature increases. These findings in 1D model are well validated by 2D simulations.« less

Particle-in-cell simulations of Hall plasma thrusters

NASA Astrophysics Data System (ADS)

Miranda, Rodrigo; Ferreira, Jose Leonardo; Martins, Alexandre

2016-07-01

Hall plasma thrusters can be modelled using particle-in-cell (PIC) simulations. In these simulations, the plasma is described by a set of equations which represent a coupled system of charged particles and electromagnetic fields. The fields are computed using a spatial grid (i.e., a discretization in space), whereas the particles can move continuously in space. Briefly, the particle and fields dynamics are computed as follows. First, forces due to electric and magnetic fields are employed to calculate the velocities and positions of particles. Next, the velocities and positions of particles are used to compute the charge and current densities at discrete positions in space. Finally, these densities are used to solve the electromagnetic field equations in the grid, which are interpolated at the position of the particles to obtain the acting forces, and restart this cycle. We will present numerical simulations using software for PIC simulations to study turbulence, wave and instabilities that arise in Hall plasma thrusters. We have sucessfully reproduced a numerical simulation of a SPT-100 Hall thruster using a two-dimensional (2D) model. In addition, we are developing a 2D model of a cylindrical Hall thruster. The results of these simulations will contribute to improve the performance of plasma thrusters to be used in Cubesats satellites currenty in development at the Plasma Laboratory at University of Brasília.

The microscopic Z-pinch process of current-carrying rarefied deuterium plasma shell

NASA Astrophysics Data System (ADS)

Ning, Cheng; Feng, Zhixing; Xue, Chuang; Li, Baiwen

2015-02-01

For insight into the microscopic mechanism of Z-pinch dynamic processes, a code of two-dimensional particle-in-cell (PIC) simulation has been developed in cylindrical coordinates. In principle, the Z-pinch of current-carrying rarefied deuterium plasma shell has been simulated by means of this code. Many results related to the microscopic processes of the Z-pinch are obtained. They include the spatio-temporal distributions of electromagnetic field, current density, forces experienced by the ions and electrons, positions and energy distributions of particles, and trailing mass and current. In radial direction, the electric and magnetic forces exerted on the electrons are comparable in magnitude, while the forces exerted on the ions are mainly the electric forces. So in the Z-pinch process, the electrons are first accelerated in Z direction and get higher velocities; then, they are driven inwards to the axis at the same time by the radial magnetic forces (i.e., Lorentz forces) of them. That causes the separations between the electrons and ions because the ion mass is much larger than the electron's, and in turn a strong electrostatic field is produced. The produced electrostatic field attracts the ions to move towards the electrons. When the electrons are driven along the radial direction to arrive at the axis, they shortly move inversely due to the static repellency among them and their tiny mass, while the ions continue to move inertially inwards, and later get into stagnation, and finally scatter outwards. Near the stagnation, the energies of the deuterium ions mostly range from 0.3 to 6 keV, while the electron energies are mostly from 5 to 35 keV. The radial components, which can contribute to the pinched plasma temperature, of the most probable energies of electron and ion at the stagnation are comparable to the Bennett equilibrium temperature (about 1 keV), and also to the highest temperatures of electron and ion obtained in one dimensional radiation magnetohydrodynamic simulation of the plasma shell Z-pinch. The trailing mass is about 20% of the total mass of the shell, and the maximum trailing current is about 7% of the driven current under our trailing definition. Our PIC simulation also demonstrates that the plasma shell first experiences a snow-plow like implosion process, which is relatively stable.

An Efficient Randomized Algorithm for Real-Time Process Scheduling in PicOS Operating System

NASA Astrophysics Data System (ADS)

Helmy*, Tarek; Fatai, Anifowose; Sallam, El-Sayed

PicOS is an event-driven operating environment designed for use with embedded networked sensors. More specifically, it is designed to support the concurrency in intensive operations required by networked sensors with minimal hardware requirements. Existing process scheduling algorithms of PicOS; a commercial tiny, low-footprint, real-time operating system; have their associated drawbacks. An efficient, alternative algorithm, based on a randomized selection policy, has been proposed, demonstrated, confirmed for efficiency and fairness, on the average, and has been recommended for implementation in PicOS. Simulations were carried out and performance measures such as Average Waiting Time (AWT) and Average Turn-around Time (ATT) were used to assess the efficiency of the proposed randomized version over the existing ones. The results prove that Randomized algorithm is the best and most attractive for implementation in PicOS, since it is most fair and has the least AWT and ATT on average over the other non-preemptive scheduling algorithms implemented in this paper.

Metabolic stability of new anticonvulsants in body fluids and organ homogenates.

PubMed

Marszałek, Dorota; Goldnik, Anna; Pluciński, Franciszek; Mazurek, Aleksander P; Jakubiak, Anna; Lis, Ewa; Tazbir, Piotr; Koziorowska, Agnieszka

2012-01-01

The stability as a function of time of compounds with established anticonvulsant activity: picolinic acid benzylamide (Pic-BZA), picolinic acid 2-fluorobenzylamide (Pic-2-F-BZA), picolinic acid 3-fluorobenzylamide (Pic-3-F-BZA), picolinic acid 4-fluorobenzylamide (Pic-4-F-BZA) and picolinic acid 2-methylbenzylamide (Pic-2-Me-BZA) in body fluids and homogenates of body organs were determined after incubation. It was found that they decompose relatively rapidly in liver and kidney and are stable against enzymes present in body fluids and some organs. These results are consistent with the bond strength expressed as total energy of amide bonds (calculated by quantum chemical methods) in the studied anticonvulsants. The calculated values of the amide bond energy are: 199.4 kcal/mol, 200.2 kcal/mol, 207.5 kcal/mol, 208.4 kcal/mol and 198.2 kcal/mol, respectively. The strength of the amide bonds in the studied anticonvulsants correctly reflects their stability in liver or kidney.

Functional interplay between Mediator and TFIIB in preinitiation complex assembly in relation to promoter architecture.

PubMed

Eychenne, Thomas; Novikova, Elizaveta; Barrault, Marie-Bénédicte; Alibert, Olivier; Boschiero, Claire; Peixeiro, Nuno; Cornu, David; Redeker, Virginie; Kuras, Laurent; Nicolas, Pierre; Werner, Michel; Soutourina, Julie

2016-09-15

Mediator is a large coregulator complex conserved from yeast to humans and involved in many human diseases, including cancers. Together with general transcription factors, it stimulates preinitiation complex (PIC) formation and activates RNA polymerase II (Pol II) transcription. In this study, we analyzed how Mediator acts in PIC assembly using in vivo, in vitro, and in silico approaches. We revealed an essential function of the Mediator middle module exerted through its Med10 subunit, implicating a key interaction between Mediator and TFIIB. We showed that this Mediator-TFIIB link has a global role on PIC assembly genome-wide. Moreover, the amplitude of Mediator's effect on PIC formation is gene-dependent and is related to the promoter architecture in terms of TATA elements, nucleosome occupancy, and dynamics. This study thus provides mechanistic insights into the coordinated function of Mediator and TFIIB in PIC assembly in different chromatin contexts. © 2016 Eychenne et al.; Published by Cold Spring Harbor Laboratory Press.

Observational Studies of the Clearing Phase in Proto-Planetary Disks Surrounding Intermediate Mass Stars

NASA Technical Reports Server (NTRS)

Grady, Carol A.

1999-01-01

A detailed study of circumstellar gas associated with young, intermediate-mass stars has demonstrated that, far from being unique or an infrequently occurring phenomenon, beta Pic-like infall activity is routinely observed in stars younger than 10-50 Myr when the observer's line of sight lies within 15 degrees of the disk mid-plane. Detailed studies of 2 Herbig Ae/Be stars, AB Aur and HD 163296 demonstrate that enhanced infall episodes last 20-60 hours, comparable to the duration of similar episodes in beta Pictoris. The infall activity is consistent with detection of the comae of swarms of star-grazing bodies of asteroidal to cometary composition. Episodic fluctuations in the infall activity are clearly present by approximately 6 Myr, and may indicate the presence of massive planets within the disk. This study has therefore, directly contributed to NASA's Origins of Planetary Systems theme by identifying under what conditions extra-solar planetesimals can be remotely sensed, indicating that such bodies appear to be routinely detectable among young stars in the 1-10 Myr range, and suggesting that temporal studies of spectroscopic variability may provide a means of identifying those systems harboring massive planets. This study has resulted in 2 refereed review papers, 13 other refereed papers, and 17 conference papers.

Boltzmann Transport in Hybrid PIC HET Modeling

DTIC Science & Technology

2015-07-01

Paper 3. DATES COVERED (From - To) July 2015-July 2015 4. TITLE AND SUBTITLE Boltzmann transport in hybrid PIC HET modeling 5a. CONTRACT NUMBER In...reproduce experimentally observed mobility trends derived from HPHall, a workhorse hybrid- PIC HET simulation code. 15. SUBJECT TERMS 16. SECURITY...CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18 . NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON Justin Koo a. REPORT Unclassified b. ABSTRACT

DoD Personnel Security Program

DTIC Science & Technology

1987-01-01

Baltimore, Maryland 21203 Message Address: DIS PIC BALTIMORE MD/ /D0640 The request will include subject’s name, grade, social security number, date and...requests for initial investigations will be submitted to PIC regardless of their urgency. If, however, there is an urgent need for a postadjudication...investigation, or the mailing of a request to PIC for initia- tion of a postadjudication case would prejudice timely pursuit of investigative action, the

iVPIC: A low-­dispersion, energy-­conserving relativistic PIC solver for LPI simulations

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

Chacon, Luis

We have developed a novel low-­dispersion, exactly energy-­conserving PIC algorithm for the relativistic Vlasov-­Maxwell system. The approach features an exact energy conservation theorem while preserving the favorable performance and numerical dispersion properties of explicit PIC. The new algorithm has the potential to enable much longer laser-­plasma-­interaction (LPI) simulations than are currently possible.

Simultaneous analysis of Cr(III), Cr(VI), and chromium picolinate in foods using capillary electrophoresis-inductively coupled plasma mass spectrometry.

PubMed

Chen, YiQuan; Chen, JinFa; Xi, Zhiming; Yang, Guidi; Wu, Zujian; Li, JianRong; Fu, FengFu

2015-05-01

We herein reported a method for the simultaneous detection of trace Cr(VI), Cr(III), and chromium(III) picolinate (CrPic) in foods using CE-ICP-MS together with ultrasonic-assisted extraction. The Cr(III) (Cr(3+) ) was chelated with trans-1,2-diaminocyclohexane-N,N,N´,N´-tetraacetic acid (DCTA) to form a single charged Cr-DCTA(-) complex. Then, Cr(VI) (CrO4 (2-) ), Cr-DCTA(-) , and CrPic were separated by CE within 8 min under a separation voltage of -13 KV followed by their monitoring with ICP mass spectrometer (ICP-MS). The proposed method is simple, effective, and sensitive. It has an instrument detection limit of 0.10, 0.18, and 0.20 ngCr/mL for Cr(VI), Cr(III), and CrPic, respectively. With the help of the methods, we have successfully determined Cr(VI), Cr(III), and CrPic in nutritional supplement (CrPic yeast tablet) with an RSD (n = 5) <6% and a recovery of 93-103%. The experimental results showed that CrPic was the main speciation of chromium in the nutritional supplement, with a concentration of 1514.6 μg Cr/g. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

PIC1, an Ancient Permease in Arabidopsis Chloroplasts, Mediates Iron Transport[W

PubMed Central

Duy, Daniela; Wanner, Gerhard; Meda, Anderson R.; von Wirén, Nicolaus; Soll, Jürgen; Philippar, Katrin

2007-01-01

In chloroplasts, the transition metals iron and copper play an essential role in photosynthetic electron transport and act as cofactors for superoxide dismutases. Iron is essential for chlorophyll biosynthesis, and ferritin clusters in plastids store iron during germination, development, and iron stress. Thus, plastidic homeostasis of transition metals, in particular of iron, is crucial for chloroplast as well as plant development. However, very little is known about iron uptake by chloroplasts. Arabidopsis thaliana PERMEASE IN CHLOROPLASTS1 (PIC1), identified in a screen for metal transporters in plastids, contains four predicted α-helices, is targeted to the inner envelope, and displays homology with cyanobacterial permease-like proteins. Knockout mutants of PIC1 grew only heterotrophically and were characterized by a chlorotic and dwarfish phenotype reminiscent of iron-deficient plants. Ultrastructural analysis of plastids revealed severely impaired chloroplast development and a striking increase in ferritin clusters. Besides upregulation of ferritin, pic1 mutants showed differential regulation of genes and proteins related to iron stress or transport, photosynthesis, and Fe-S cluster biogenesis. Furthermore, PIC1 and its cyanobacterial homolog mediated iron accumulation in an iron uptake–defective yeast mutant. These observations suggest that PIC1 functions in iron transport across the inner envelope of chloroplasts and hence in cellular metal homeostasis. PMID:17337631

Independent contrasts and PGLS regression estimators are equivalent.

PubMed

Blomberg, Simon P; Lefevre, James G; Wells, Jessie A; Waterhouse, Mary

2012-05-01

We prove that the slope parameter of the ordinary least squares regression of phylogenetically independent contrasts (PICs) conducted through the origin is identical to the slope parameter of the method of generalized least squares (GLSs) regression under a Brownian motion model of evolution. This equivalence has several implications: 1. Understanding the structure of the linear model for GLS regression provides insight into when and why phylogeny is important in comparative studies. 2. The limitations of the PIC regression analysis are the same as the limitations of the GLS model. In particular, phylogenetic covariance applies only to the response variable in the regression and the explanatory variable should be regarded as fixed. Calculation of PICs for explanatory variables should be treated as a mathematical idiosyncrasy of the PIC regression algorithm. 3. Since the GLS estimator is the best linear unbiased estimator (BLUE), the slope parameter estimated using PICs is also BLUE. 4. If the slope is estimated using different branch lengths for the explanatory and response variables in the PIC algorithm, the estimator is no longer the BLUE, so this is not recommended. Finally, we discuss whether or not and how to accommodate phylogenetic covariance in regression analyses, particularly in relation to the problem of phylogenetic uncertainty. This discussion is from both frequentist and Bayesian perspectives.

Biodistribution of charged F(ab')2 photoimmunoconjugates in a xenograft model of ovarian cancer.

PubMed Central

Duska, L. R.; Hamblin, M. R.; Bamberg, M. P.; Hasan, T.

1997-01-01

The effect of charge modification of photoimmunoconjugates (PICs) on their biodistribution in a xenograft model of ovarian cancer was investigated. Chlorin(e6)c(e6) was attached site specifically to the F(ab')2 fragment of the murine monoclonal antibody OC125, directed against human ovarian cancer cells, via poly-1-lysine linkers carrying cationic or anionic charges. Preservation of immunoreactivity was checked by enzyme-linked immunosorbent assay (ELISA). PICs were radiolabelled with 125I and compared with non-specific rabbit IgG PICs after intraperitoneal (i.p.) injection into nude mice. Samples were taken from normal organs and tumour at 3 h and 24 h. Tumour to normal 125I ratios showed that the cationic OC125F(ab')2 PIC had the highest tumour selectivity. Ratios for c(e6) were uniformly higher than for 125I, indicating that c(e6) became separated from 125I. OC125F(ab')2 gave highest tissue values of 125I, followed by cationic OC125F(ab')2 PIC; other species were much lower. The amounts of c(e6) delivered per gram of tumour were much higher for cationic OC125F(ab')2 PIC than for other species. The results indicate that cationic charge stimulates the endocytosis and lysosomal degradation of the OC125F(ab')2-pl-c(e6) that has bound to the i.p. tumour. Positively charged PICs may have applications in the i.p. photoimmunotherapy of minimal residual ovarian cancer. PMID:9062404

Exposure of pregnant mice to chromium picolinate results in skeletal defects in their offspring.

PubMed

Bailey, M M; Boohaker, J G; Sawyer, R D; Behling, J E; Rasco, J F; Jernigan, J J; Hood, R D; Vincent, J B

2006-06-01

Chromium(III) picolinate, [Cr(pic)(3)], is a widely marketed dietary supplement. However, Cr(pic)(3) has been associated with oxidative damage to DNA in rats and mutations and DNA fragmentation in cell cultures. In isolated case reports, Cr(pic)(3) supplementation has been said to cause adverse effects, such as anemia, renal failure, liver dysfunction, and neuronal impairment. To date, no studies have been published regarding the safety of chromium picolinate supplementation to a developing fetus, although Cr(pic)(3) has been recommended for pregnant women who are diagnosed with gestational diabetes. From gestation days (GD) 6-17, pregnant CD-1 mice were fed diets containing either 200 mg/kg Cr(pic)(3), 200 mg/kg CrCl(3), 174 mg/kg picolinic acid, or the diet only to determine if Cr(pic)(3), CrCl(3), or picolinic acid could cause developmental toxicity. Dams were sacrificed on GD 17, and their litters were examined for adverse effects. The incidence of bifurcated cervical arches was significantly increased in fetuses from the Cr(pic)(3) group as compared to the diet-only group. Fetuses in the picolinic acid-treated group had an incidence double that of the control group; however, this increase was not statistically significant. Fetuses in the CrCl(3) group did not differ from the controls in any variable examined. No maternal toxicity was observed in any of the treatment groups. High maternal oral exposures to chromium picolinate can cause morphological defects in developing offspring of mice.

Accidental pharmacological poisonings in young children: population-based study in three settings.

PubMed

Bell, Jane C; Bentley, Jason P; Downie, Catriona; Cairns, Rose; Buckley, Nicholas A; Katelaris, Annette; Pearson, Sallie-Anne; Nassar, Natasha

2018-01-15

Pharmacological poisonings in young children are avoidable. Previous studies report calls to poisons centres, presentations to emergency departments (ED) or hospital admissions. There are limited data assessing concurrent management of poisonings across all three settings. We aimed to describe accidental pharmacological poisonings in young children across our Poisons Information Centre (PIC), EDs and hospitals. A population-based study in New South Wales, Australia, of PIC calls, ED presentations and hospital admissions for accidental pharmacological poisoning in children aged <5 years, 2007-2013. We examined trends, medicines responsible and subsequent management. Medicines were coded using ICD10-AM diagnosis codes (T36-50). Over 2007-2013, pharmacological poisonings accounted for 67,816 PIC calls, 7739 ED presentations and 2082 admissions. Rates (per 10,000 children) of PIC calls declined from 220 to 178; ED presentations were stable (∼22-24), with a decrease in emergency cases offset by an increase in semi- or non-urgent presentations; hospital admissions declined (8-5). Most PIC calls related to "non-opioid analgesics" (25%), and "topical agents" (18%). Nearly every day, one child aged <5 years was admitted to hospital for poisoning. "Benzodiazepines", "other and unspecified antidepressants", "uncategorised antihypertensives", and "4-aminophenol derivatives" accounted for over one-third of all admissions. Most PIC calls (90%) were advised to stay home, 6% referred to hospital. One-quarter of ED presentations resulted in admission. Poisonings reported to PIC and hospitals declined, however, non-urgent ED presentations increased. Strategies to reduce therapeutic errors and access to medicines, and education campaigns to improve Poisons Centre call rates to prevent unnecessary ED presentations are needed.

Effect of dental cements on peri-implant microbial community: comparison of the microbial communities inhabiting the peri-implant tissue when using different luting cements.

PubMed

Korsch, Michael; Marten, Silke-Mareike; Dötsch, Andreas; Jáuregui, Ruy; Pieper, Dietmar H; Obst, Ursula

2016-12-01

Cementing dental restorations on implants poses the risk of undetected excess cement. Such cement remnants may favor the development of inflammation in the peri-implant tissue. The effect of excess cement on the bacterial community is not yet known. The aim of this study was to analyze the effect of two different dental cements on the composition of the microbial peri-implant community. In a cohort of 38 patients, samples of the peri-implant tissue were taken with paper points from one implant per patient. In 15 patients, the suprastructure had been cemented with a zinc oxide-eugenol cement (Temp Bond, TB) and in 23 patients with a methacrylate cement (Premier Implant Cement, PIC). The excess cement found as well as suppuration was documented. Subgingival samples of all patients were analyzed for taxonomic composition by means of 16S amplicon sequencing. None of the TB-cemented implants had excess cement or suppuration. In 14 (61%) of the PIC, excess cement was found. Suppuration was detected in 33% of the PIC implants without excess cement and in 100% of the PIC implants with excess cement. The taxonomic analysis of the microbial samples revealed an accumulation of oral pathogens in the PIC patients independent of the presence of excess cement. Significantly fewer oral pathogens occurred in patients with TB compared to patients with PIC. Compared with TB, PIC favors the development of suppuration and the growth of periodontal pathogens. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Absolute radiometric calibration of Landsat using a pseudo invariant calibration site

USGS Publications Warehouse

Helder, D.; Thome, K.J.; Mishra, N.; Chander, G.; Xiong, Xiaoxiong; Angal, A.; Choi, Tae-young

2013-01-01

Pseudo invariant calibration sites (PICS) have been used for on-orbit radiometric trending of optical satellite systems for more than 15 years. This approach to vicarious calibration has demonstrated a high degree of reliability and repeatability at the level of 1-3% depending on the site, spectral channel, and imaging geometries. A variety of sensors have used this approach for trending because it is broadly applicable and easy to implement. Models to describe the surface reflectance properties, as well as the intervening atmosphere have also been developed to improve the precision of the method. However, one limiting factor of using PICS is that an absolute calibration capability has not yet been fully developed. Because of this, PICS are primarily limited to providing only long term trending information for individual sensors or cross-calibration opportunities between two sensors. This paper builds an argument that PICS can be used more extensively for absolute calibration. To illustrate this, a simple empirical model is developed for the well-known Libya 4 PICS based on observations by Terra MODIS and EO-1 Hyperion. The model is validated by comparing model predicted top-of-atmosphere reflectance values to actual measurements made by the Landsat ETM+ sensor reflective bands. Following this, an outline is presented to develop a more comprehensive and accurate PICS absolute calibration model that can be Système international d'unités (SI) traceable. These initial concepts suggest that absolute calibration using PICS is possible on a broad scale and can lead to improved on-orbit calibration capabilities for optical satellite sensors.

Double-Stranded RNA-Dependent Protein Kinase Regulates the Motility of Breast Cancer Cells

PubMed Central

Xu, Mei; Chen, Gang; Wang, Siying; Liao, Mingjun; Frank, Jacqueline A.; Bower, Kimberly A.; Zhang, Zhuo; Shi, Xianglin; Luo, Jia

2012-01-01

Double-stranded RNA (dsRNA)-dependent protein kinase (PKR) is an interferon-induced protein kinase that plays a central role in the anti-viral process. Due to its pro-apoptotic and anti-proliferative action, there is an increased interest in PKR modulation as an anti-tumor strategy. PKR is overexpressed in breast cancer cells; however, the role of PKR in breast cancer cells is unclear. The expression/activity of PKR appears inversely related to the aggressiveness of breast cancer cells. The current study investigated the role of PKR in the motility/migration of breast cancer cells. The activation of PKR by a synthesized dsRNA (PIC) significantly decreased the motility of several breast cancer cell lines (BT474, MDA-MB231 and SKBR3). PIC inhibited cell migration and blocked cell membrane ruffling without affecting cell viability. PIC also induced the reorganization of the actin cytoskeleton and impaired the formation of lamellipodia. These effects of PIC were reversed by the pretreatment of a selective PKR inhibitor. PIC also activated p38 mitogen-activated protein kinase (MAPK) and its downstream MAPK-activated protein kinase 2 (MK2). PIC-induced activation of p38 MAPK and MK2 was attenuated by the PKR inhibitor and the PKR siRNA, but a selective p38 MAPK inhibitor (SB203580) or other MAPK inhibitors did not affect PKR activity, indicating that PKR is upstream of p38 MAPK/MK2. Cofilin is an actin severing protein and regulates membrane ruffling, lamellipodia formation and cell migration. PIC inhibited cofilin activity by enhancing its phosphorylation at Ser3. PIC activated LIM kinase 1 (LIMK1), an upstream kinase of cofilin in a p38 MAPK-dependent manner. We concluded that the activation of PKR suppressed cell motility by regulating the p38 MAPK/MK2/LIMK/cofilin pathway. PMID:23112838

Identification of amino acid residues of mammalian mitochondrial phosphate carrier important for its functional expression in yeast cells, as achieved by PCR-mediated random mutation and gap-repair cloning.

PubMed

Yamagoshi, Ryohei; Yamamoto, Takenori; Hashimoto, Mitsuru; Sugahara, Ryohei; Shiotsuki, Takahiro; Miyoshi, Hideto; Terada, Hiroshi; Shinohara, Yasuo

2017-01-01

The mitochondrial phosphate carrier (PiC) of mammals, but not the yeast one, is synthesized with a presequence. The deletion of this presequence of the mammalian PiC was reported to facilitate the import of the carrier into yeast mitochondria, but the question as to whether or not mammalian PiC could be functionally expressed in yeast mitochondria was not addressed. In the present study, we first examined whether the defective growth on a glycerol plate of yeast cells lacking the yeast PiC gene could be reversed by the introduction of expression vectors of rat PiCs. The introduction of expression vectors encoding full-length rat PiC (rPiC) or rPiC lacking the presequence (ΔNrPiC) was ineffective in restoring growth on the glycerol plates. When we examined the expression levels of individual rPiCs in yeast mitochondria, ΔNrPiC was expressed at a level similar to that of yeast PiC, but that of rPiC was very low. These results indicated that ΔNrPiC expressed in yeast mitochondria is inert. Next, we sought to isolate "revertants" viable on the glycerol plate by expressing randomly mutated ΔNrPiC, and obtained two clones. These clones carried either of two mutations, F267S or F282S; and these mutations restored the transport function of ΔNrPiC in yeast mitochondria. These two Phe residues were conserved in human carrier (hPiC), and the transport function of ΔNhPiC expressed in yeast mitochondria was also markedly improved by their substitutions. Thus, substitution of F267S or F282S was concluded to be important for functional expression of mammalian PiCs in yeast mitochondria. Copyright © 2016 Elsevier B.V. and Mitochondria Research Society. All rights reserved.

Beta-lactam resistance in the gram negatives: increasing complexity of conditional, composite and multiply resistant phenotypes.

PubMed

Iredell, Jon; Thomas, Lee; Espedido, Björn

2006-12-01

The greatest impact of microbiology data on clinical care is in the critically ill. Unfortunately, this is also the area in which microbiology laboratories are most often non-contributive. Attempts to move to rapid, culture-independent diagnostics are driven by the need to expedite urgent results. This is difficult in Gram-negative infection because of the complexity of the antibiotic resistance phenotype. Here, we discuss resistance to modern beta-lactams as a case in point. Recent outbreaks of transmissible carbapenem resistance among Gram-negative enteric pathogens in Sydney and Melbourne serve to illustrate the pitfalls of traditional phenotypical approaches. A better understanding of the epidemiology and mosaic nature of antibiotic resistance elements in the microflora is needed for us to move forward.

Beta Pic-like Circumstellar Gas Disk Around 2 And

NASA Technical Reports Server (NTRS)

Cheng, Patricia

2003-01-01

This grant was awarded to support the data analysis and publication of results from our project entitled P Pic-like Circumstellar Gas Disk Around 2 And . We proposed to obtain FUSE observations of 2 And and study the characteristics and origin of its circumstellar gas. We observed 2 Andromedae with FUSE on 3-4 July 2001 in 11 exposures with a total exposure time of 21,289 seconds through the LWRS aperture. Our data were calibrated with Version 1.8.7 of the CALFUSE pipeline processing software. We corrected the wavelength scale for the heliocentric velocity error in this version of the CALFUSE software. The relative accuracy of the calibrated wavelength scale is +/- 9 km/s . We produced a co-added spectrum in the LiF 1B and LiF 2A channels (covering the 1100 to 1180 A region) by cross-correlating the 11 individual exposures and doing an exposure-time weighted average flux. The final co-added spectra have a signal-to-noise ratio in the stellar continuum near 1150 A of about 20. To obtain an absolute wavelength calibration, we cross-correlated our observed spectra with a model spectrum to obtain the best fit for the photospheric C I lines. Because the photospheric lines are very broad, this yields an absolute accuracy for the wavelength scale of approx.+/- 15 km/s. We then rebinned 5 original pixels to yield the optimal sampling of .033 A for each new pixel, because the calibrated spectra oversample the spectral resolution for FUSE+LWRS (R = 20,000 +/- 2,000).

[Relationship between the expression of beta-cat, cyclin D1 and c-myc and the occurance and biological behavior of pancreatic cancer].

PubMed

Li, Yu-jun; Ji, Xiang-rui

2003-06-01

To study the relationship between the abnormal expression of beta-catenin (beta-cat) and the high expressions of cyclin D1 and c-myc and the occurance, proliferation, infiltration, metastasis and prognosis of pancreatic cancer, and to provide rational basis for the clinical diagnosis and treatment. Immunohistochemical PicTure trade mark was used to examine the expressions of beta-cat, cyclin D1 and c-myc in 47 cases of the cancerous tissue of pancreas, 12 cases of the pancreatic intraepithelial neoplasia and 10 cases of normal tissue of pancreas, respectively. Pancreatic cancer proliferation cell nuclear antigen (PCNA) was also tested as the index of the extent of proliferation of the pancreatic cancer. beta-cat was expressed normally in the 10 cases of the normal pancreatic tissue, while cyclin D1 and c-myc were negative. The expression rates of beta-cat, cyclin D1 and c-myc in the tissues of the pancreatic intraepithelial neoplasia and the pancreatic cancer had no significant difference [6/12 and 68.1% (32/47), 6/12 and 74.5% (35/47), 5/12 and 70.2% (33/47) respectively;P values were all more than 0.05]. The abnormal expression rate of beta-cat was significantly correlated to the metastasis of the pancreatic cancer and the one-year survival rate (both P < 0.05), but had no relation with the size, the extent of differentiation, the activity of proliferation, or infiltration of the pancreatic cancer (both P > 0.05). The expression rate of cyclin D1 was correlated with the proliferation of the pancreatic cancer and the extent of differentiation (both P < 0.05), but not with the size, infiltration, metastasis, or one-year survival rate of the pancreatic cancer (both P > 0.05). The expression rate of c-myc was not correlated with the size, the extent of proliferation, infiltration, metastasis, or one-year survival rate (both P > 0.05), but closely with the proliferation activity of the cancerous tissue of pancreas (P < 0.05). The abnormal expression of beta-cat and the high expressions of cyclin D1 and c-myc had a parallel relationship with the pancreatic intraepithelial neoplasia and pancreatic cancer (both P < 0.05, gamma = 1.000, 0.845, 0.437, 0.452). The abnormal expression of beta-cat activates cyclin D1 and c-myc, and results in the unchecked proliferation and differentiation, which may play an important role in the genesis of the pancreatic cancer. The abnormal expression of beta-cat is one of the mechanisms for the spread of pancreatic cancer and an index in the molecular biology to determine the metastasis and prognosis of pancreatic cancer.

Radiation and Thermal Effects on Used Nuclear Fuel and Nuclear Waste Forms

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

Weber, William J.; Zhang, Yanwen

This is the final report of the NEUP project “Radiation and Thermal Effects on Used Nuclear Fuel and Nuclear Waste Forms.” This project started on July 1, 2012 and was successfully completed on June 30, 2016. This report provides an overview of the main achievements, results and findings through the duration of the project. Additional details can be found in the main body of this report and in the individual Quarterly Reports and associated Deliverables of this project, which have been uploaded in PICS-NE. The objective of this research was to advance understanding and develop validated models on the effectsmore » of self-radiation from beta and alpha decay on the response of used nuclear fuel and nuclear waste forms during high-temperature interim storage and long-term permanent disposition. To achieve this objective, model used-fuel materials and model waste form materials were identified, fabricated, and studied.« less

Polarization-dependent imaging contrast in abalone shells

NASA Astrophysics Data System (ADS)

Metzler, Rebecca A.; Zhou, Dong; Abrecht, Mike; Chiou, Jau-Wern; Guo, Jinghua; Ariosa, Daniel; Coppersmith, Susan N.; Gilbert, P. U. P. A.

2008-02-01

Many biominerals contain micro- or nanocrystalline mineral components, organized accurately into architectures that confer the material with improved mechanical performance at the macroscopic scale. We present here an effect which enables us to observe the relative orientation of individual crystals at the submicron scale. We call it polarization-dependent imaging contrast (PIC), as it is an imaging development of the well-known x-ray linear dichroism. Most importantly, PIC is obtained in situ, in biominerals. We present here PIC in the prismatic and nacreous layers of Haliotis rufescens (red abalone), confirm it in geologic calcite and aragonite, and corroborate the experimental data with theoretical simulated spectra. PIC reveals different and unexpected aspects of nacre architecture that have inspired theoretical models for nacre formation.

[PICS: pharmaceutical inspection cooperation scheme].

PubMed

Morénas, J

2009-01-01

The pharmaceutical inspection cooperation scheme (PICS) is a structure containing 34 participating authorities located worldwide (October 2008). It has been created in 1995 on the basis of the pharmaceutical inspection convention (PIC) settled by the European free trade association (EFTA) in1970. This scheme has different goals as to be an international recognised body in the field of good manufacturing practices (GMP), for training inspectors (by the way of an annual seminar and experts circles related notably to active pharmaceutical ingredients [API], quality risk management, computerized systems, useful for the writing of inspection's aide-memoires). PICS is also leading to high standards for GMP inspectorates (through regular crossed audits) and being a room for exchanges on technical matters between inspectors but also between inspectors and pharmaceutical industry.

Measurements of total production cross sections for $$\\pi^{+}$$+C, $$\\pi^{+}$$+Al, $$K^{+}$$+C, and $$K^{+}$$+Al at 60 GeV/c and $$\\pi^{+}$$+C and $$\\pi^{+}$$+Al at 31 GeV/c

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

Aduszkiewicz, A.; et al.

This paper presents several measurements of total production cross sections and total inelastic cross sections for the following reactions:more » $$\\pi^{+}$$+C, $$\\pi^{+}$$+Al, $$K^{+}$$+C, $$K^{+}$$+Al at 60 GeV/c, $$\\pi^{+}$$+C and $$\\pi^{+}$$+Al at 31 GeV/c . The measurements were made using the NA61/SHINE spectrometer at the CERN SPS. Comparisons with previous measurements are given and good agreement is seen. These interaction cross sections measurements are a key ingredient for neutrino flux prediction from the reinteractions of secondary hadrons in current and future accelerator-based long-baseline neutrino experiments.« less

Cost-effective treatment of low-risk carcinoma not invading bladder muscle.

PubMed

Green, David A; Rink, Michael; Cha, Eugene K; Xylinas, Evanguelos; Chughtai, Bilal; Scherr, Douglas S; Shariat, Shahrokh F; Lee, Richard K

2013-03-01

Study Type - Therapy (cost effectiveness analysis) Level of Evidence 2a What's known on the subject? and What does the study add? Bladder cancer is one of the costliest malignancies to treat throughout the life of a patient. The most cost-effective management for low-risk non-muscle-invasive bladder cancer is not known. The current study shows that employing cystoscopic office fulguration for low-risk appearing bladder cancer recurrences can materially impact the cost-effectiveness of therapy. In a follow-up protocol where office fulguration is routinely employed for low-risk bladder cancers, peri-operative intravesical chemotherapy may not provide any additional cost-effectiveness benefit. To examine the cost-effectiveness of fulguration vs transurethral resection of bladder tumour (TURBT) with and without perioperative intravesical chemotherapy (PIC) for managing low-risk carcinoma not invading bladder muscle (NMIBC). Low-risk NMIBC carries a low progression rate, lending support to the use of office-based fulguration for small recurrences rather than traditional TURBT. A Markov state transition model was created to simulate treatment of NMIBC with vs without PIC, with recurrence treated by formal TURBT vs treatment with fulguration. Costing data were obtained from the Medicare Resource Based Relative Value Scale. Data regarding the success of PIC were obtained from the peer-reviewed literature, as were corresponding utilities for bladder cancer-related procedures. Sensitivity analyses were performed. At 5-year follow-up, a strategy of fulguration without PIC was the most cost-effective (mean cost-effectiveness = US $654.8/quality-adjusted life year), despite a lower recurrence rate with PIC. Both fulguration strategies dominated each TURBT strategy. Sensitivity analysis showed that fulguration without PIC dominated all other strategies when the recurrence rate after PIC was increased to ≥14.2% per year. Similarly, the cost-effectiveness of TURBT becomes more competitive with fulguration when the total cost of TURBT declines < US $1175. The present study shows that fulguration without PIC was the most cost-effective strategy for treating low-risk NMIBC. The effectiveness of PIC and the cost of TURBT can materially impact the cost-effectiveness of the different management strategies. These results should be considered in treatment decisions in the context of preserving oncological control. © 2012 BJU INTERNATIONAL.

Metadata, PICS and Quality.

ERIC Educational Resources Information Center

Armstrong, C. J.

1997-01-01

Discusses PICS (Platform for Internet Content Selection), the Centre for Information Quality Management (CIQM), and metadata. Highlights include filtering networked information; the quality of information; and standardizing search engines. (LRW)

Teaching Elementary Particle Physics, Part II

NASA Astrophysics Data System (ADS)

Hobson, Art

2011-03-01

In order to explain certain features of radioactive beta decay, Wolfgang Pauli suggested in 1930 that the nucleus emitted, in addition to a beta particle, another particle of an entirely new type. The hypothesized particle, dubbed the neutrino, would not be discovered experimentally for another 25 years. It's not easy to detect neutrinos, because they respond to neither the EM force nor the strong force. For example, the mean free path (average penetration distance before it interacts) of a typical beta-decay neutrino moving through solid lead is about 1.5 light years! Enrico Fermi argued that neutrinos indicated a new force was at work. During the 1930s, he quickly adapted ideas from the developing new theory of QED to this new force, dubbed the weak force. Fermi's theory was able to predict the half-lives of beta-emitting nuclei and the range of energies of the emitted beta particles.

Electron ionization of SiCl4

NASA Astrophysics Data System (ADS)

King, Simon J.; Price, Stephen D.

2011-02-01

Relative partial ionization cross sections (PICS) for the formation of fragment ions following electron ionization of SiCl4, in the electron energy range 30-200 eV, have been determined using time-of-flight mass spectrometry coupled with an ion coincidence technique. By this method, the contributions to the yield of each fragment ion from dissociative single, double, and triple ionization, are distinguished. These yields are quantified in the form of relative precursor-specific PICS, which are reported here for the first time for SiCl4. For the formation of singly charged ionic fragments, the low-energy maxima appearing in the PICS curves are due to contributions from single ionization involving predominantly indirect ionization processes, while contributions to the yields of these ions at higher electron energies are often dominated by dissociative double ionization. Our data, in the reduced form of relative PICS, are shown to be in good agreement with a previous determination of the PICS of SiCl4. Only for the formation of doubly charged fragment ions are the current relative PICS values lower than those measured in a previous study, although both datasets agree within combined error limits. The relative PICS data presented here include the first quantitative measurements of the formation of Cl2+ fragment ions and of the formation of ion pairs via dissociative double ionization. The peaks appearing in the 2D ion coincidence data are analyzed to provide further information concerning the mechanism and energetics of the charge-separating dissociations of SiCl42+. The lowest energy dicationic precursor state, leading to SiCl3+ + Cl+ formation, lies 27.4 ± 0.3 eV above the ground state of SiCl4 and is in close agreement with a calculated value of the adiabatic double ionization energy (27.3 eV).

Electron ionization of SiCl4.

PubMed

King, Simon J; Price, Stephen D

2011-02-21

Relative partial ionization cross sections (PICS) for the formation of fragment ions following electron ionization of SiCl(4), in the electron energy range 30-200 eV, have been determined using time-of-flight mass spectrometry coupled with an ion coincidence technique. By this method, the contributions to the yield of each fragment ion from dissociative single, double, and triple ionization, are distinguished. These yields are quantified in the form of relative precursor-specific PICS, which are reported here for the first time for SiCl(4). For the formation of singly charged ionic fragments, the low-energy maxima appearing in the PICS curves are due to contributions from single ionization involving predominantly indirect ionization processes, while contributions to the yields of these ions at higher electron energies are often dominated by dissociative double ionization. Our data, in the reduced form of relative PICS, are shown to be in good agreement with a previous determination of the PICS of SiCl(4). Only for the formation of doubly charged fragment ions are the current relative PICS values lower than those measured in a previous study, although both datasets agree within combined error limits. The relative PICS data presented here include the first quantitative measurements of the formation of Cl(2) (+) fragment ions and of the formation of ion pairs via dissociative double ionization. The peaks appearing in the 2D ion coincidence data are analyzed to provide further information concerning the mechanism and energetics of the charge-separating dissociations of SiCl(4) (2+). The lowest energy dicationic precursor state, leading to SiCl(3) (+) + Cl(+) formation, lies 27.4 ± 0.3 eV above the ground state of SiCl(4) and is in close agreement with a calculated value of the adiabatic double ionization energy (27.3 eV).

Elevations in the Fasting Serum Proinsulin-to-C-Peptide Ratio Precede the Onset of Type 1 Diabetes.

PubMed

Sims, Emily K; Chaudhry, Zunaira; Watkins, Renecia; Syed, Farooq; Blum, Janice; Ouyang, Fangqian; Perkins, Susan M; Mirmira, Raghavendra G; Sosenko, Jay; DiMeglio, Linda A; Evans-Molina, Carmella

2016-09-01

We tested whether an elevation in the serum proinsulin-to-C-peptide ratio (PI:C), a biomarker of β-cell endoplasmic reticulum (ER) dysfunction, was associated with progression to type 1 diabetes. Fasting total PI and C levels were measured in banked serum samples obtained from TrialNet Pathway to Prevention (PTP) participants, a cohort of autoantibody-positive relatives without diabetes of individuals with type 1 diabetes. Samples were obtained ∼12 months before diabetes onset from PTP progressors in whom diabetes developed (n = 60), and were compared with age-, sex-, and BMI-matched nonprogressors who remained normoglycemic (n = 58). PI:C ratios were calculated as molar ratios and were multiplied by 100% to obtain PI levels as a percentage of C levels. Although absolute PI levels did not differ between groups, PI:C ratios were significantly increased in antibody-positive subjects in whom there was progression to diabetes compared with nonprogressors (median 1.81% vs. 1.17%, P = 0.03). The difference between groups was most pronounced in subjects who were ≤10 years old, where the median progressor PI:C ratio was nearly triple that of nonprogressors; 90.0% of subjects in this age group within the upper PI:C quartile progressed to the development of diabetes. Logistic regression analysis, adjusted for age and BMI, demonstrated increased odds of progression for higher natural log PI:C ratio values (odds ratio 1.44, 95% CI 1.02, 2.05). These data suggest that β-cell ER dysfunction precedes type 1 diabetes onset, especially in younger children. Elevations in the serum PI:C ratio may have utility in predicting the onset of type 1 diabetes in the presymptomatic phase. © 2016 by the American Diabetes Association.

Elevations in the Fasting Serum Proinsulin–to–C-Peptide Ratio Precede the Onset of Type 1 Diabetes

PubMed Central

Sims, Emily K.; Chaudhry, Zunaira; Watkins, Renecia; Syed, Farooq; Blum, Janice; Ouyang, Fangqian; Perkins, Susan M.; Mirmira, Raghavendra G.; Sosenko, Jay; DiMeglio, Linda A.

2016-01-01

OBJECTIVE We tested whether an elevation in the serum proinsulin–to–C-peptide ratio (PI:C), a biomarker of β-cell endoplasmic reticulum (ER) dysfunction, was associated with progression to type 1 diabetes. RESEARCH DESIGN AND METHODS Fasting total PI and C levels were measured in banked serum samples obtained from TrialNet Pathway to Prevention (PTP) participants, a cohort of autoantibody-positive relatives without diabetes of individuals with type 1 diabetes. Samples were obtained ∼12 months before diabetes onset from PTP progressors in whom diabetes developed (n = 60), and were compared with age-, sex-, and BMI-matched nonprogressors who remained normoglycemic (n = 58). PI:C ratios were calculated as molar ratios and were multiplied by 100% to obtain PI levels as a percentage of C levels. RESULTS Although absolute PI levels did not differ between groups, PI:C ratios were significantly increased in antibody-positive subjects in whom there was progression to diabetes compared with nonprogressors (median 1.81% vs. 1.17%, P = 0.03). The difference between groups was most pronounced in subjects who were ≤10 years old, where the median progressor PI:C ratio was nearly triple that of nonprogressors; 90.0% of subjects in this age group within the upper PI:C quartile progressed to the development of diabetes. Logistic regression analysis, adjusted for age and BMI, demonstrated increased odds of progression for higher natural log PI:C ratio values (odds ratio 1.44, 95% CI 1.02, 2.05). CONCLUSIONS These data suggest that β-cell ER dysfunction precedes type 1 diabetes onset, especially in younger children. Elevations in the serum PI:C ratio may have utility in predicting the onset of type 1 diabetes in the presymptomatic phase. PMID:27385327

Planktic foraminifer and coccolith contribution to carbonate export fluxes over the central Kerguelen Plateau

NASA Astrophysics Data System (ADS)

Rembauville, M.; Meilland, J.; Ziveri, P.; Schiebel, R.; Blain, S.; Salter, I.

2016-05-01

We report the contribution of planktic foraminifers and coccoliths to the particulate inorganic carbon (PIC) export fluxes collected over an annual cycle (October 2011/September 2012) on the central Kerguelen Plateau in the Antarctic Zone (AAZ) south of the Polar Front (PF). The seasonality of PIC flux was decoupled from surface chlorophyll a concentration and particulate organic carbon (POC) fluxes and was characterized by a late summer (February) maximum. This peak was concomitant with the highest satellite-derived sea surface PIC and corresponded to a Emiliania huxleyi coccoliths export event that accounted for 85% of the annual PIC export. The foraminifer contribution to the annual PIC flux was much lower (15%) and dominated by Turborotalita quinqueloba and Neogloboquadrina pachyderma. Foraminifer export fluxes were closely related to the surface chlorophyll a concentration, suggesting food availability as an important factor regulating the foraminifer's biomass. We compared size-normalized test weight (SNW) of the foraminifers with previously published SNW from the Crozet Islands using the same methodology and found no significant difference in SNW between sites for a given species. However, the SNW was significantly species-specific with a threefold increase from T. quinqueloba to Globigerina bulloides. The annual PIC:POC molar ratio of 0.07 was close to the mean ratio for the global ocean and lead to a low carbonate counter pump effect (~5%) compared to a previous study north of the PF (6-32%). We suggest that lowers counter pump effect south of the PF despite similar productivity levels is due to a dominance of coccoliths in the PIC fluxes and a difference in the foraminifers species assemblage with a predominance of polar species with lower SNW.

Coherent optical monolithic phased-array antenna steering system

DOEpatents

Hietala, Vincent M.; Kravitz, Stanley H.; Vawter, Gregory A.

1994-01-01

An optical-based RF beam steering system for phased-array antennas comprising a photonic integrated circuit (PIC). The system is based on optical heterodyning employed to produce microwave phase shifting by a monolithic PIC constructed entirely of passive components. Microwave power and control signal distribution to the antenna is accomplished by optical fiber, permitting physical separation of the PIC and its control functions from the antenna. The system reduces size, weight, complexity, and cost of phased-array antenna systems.

Appropriateness of the food-pics image database for experimental eating and appetite research with adolescents.

PubMed

Jensen, Chad D; Duraccio, Kara M; Barnett, Kimberly A; Stevens, Kimberly S

2016-12-01

Research examining effects of visual food cues on appetite-related brain processes and eating behavior has proliferated. Recently investigators have developed food image databases for use across experimental studies examining appetite and eating behavior. The food-pics image database represents a standardized, freely available image library originally validated in a large sample primarily comprised of adults. The suitability of the images for use with adolescents has not been investigated. The aim of the present study was to evaluate the appropriateness of the food-pics image library for appetite and eating research with adolescents. Three hundred and seven adolescents (ages 12-17) provided ratings of recognizability, palatability, and desire to eat, for images from the food-pics database. Moreover, participants rated the caloric content (high vs. low) and healthiness (healthy vs. unhealthy) of each image. Adolescents rated approximately 75% of the food images as recognizable. Approximately 65% of recognizable images were correctly categorized as high vs. low calorie and 63% were correctly classified as healthy vs. unhealthy in 80% or more of image ratings. These results suggest that a smaller subset of the food-pics image database is appropriate for use with adolescents. With some modifications to included images, the food-pics image database appears to be appropriate for use in experimental appetite and eating-related research conducted with adolescents. Copyright © 2016 Elsevier Ltd. All rights reserved.

Absorption, excretion and retention of 51Cr from labelled Cr-(III)-picolinate in rats.

PubMed

Kottwitz, Karin; Laschinsky, Niels; Fischer, Roland; Nielsen, Peter

2009-04-01

The bioavailability of chromium from Cr-picolinate (CrPic(3)) and Cr-chloride (CrCl(3)) was studied in rats using (51)Cr-labelled compounds and whole-body-counting. The intestinal absorption of Cr was twice as high from CrPic(3) (1.16% vs 0.55%) than from CrCl(3), however most of the absorbed (51)Cr from CrPic(3) was excreted into the urine within 24 h. After i.v. or i.p. injection, the whole-body retention curves fitted well to a multiexponential function, demonstrating that plasma chromium is in equilibrium with three pools. For CrPic(3), a large pool exists with a very rapid exchange (T (1/2) = <0.5 days), suggesting that CrPic(3) is absorbed as intact molecule, from which the main part is directly excreted by the kidney before degradation of the chromium complex in the liver can occur. CrCl(3) is less well absorbed but the rapid exchange pool is much smaller, resulting in even higher Cr concentrations in tissue such as muscle and fat. However, 1-3 days after application, the relative distribution of (51)Cr from both compounds was similar in all tissues studied, indicating that both compounds contribute to the same storage pool. In summary, the bioavailability of CrPic(3) in rats is not superior compared to CrCl(3).

Aerobic training reduces oxidative stress in skeletal muscle of rats exposed to air pollution and supplemented with chromium picolinate.

PubMed

Marmett, Bruna; Nunes, Ramiro Barcos; de Souza, Kellen Sábio; Lago, Pedro Dal; Rhoden, Cláudia Ramos

2018-12-01

The purpose of this study was to investigate the effects of chromium picolinate (CrPic) supplementation associated with aerobic exercise using measures of oxidative stress in rats exposed to air pollution. Sixty-one male Wistar rats were divided into eight groups: residual oil fly ash (ROFA) exposure and sedentary (ROFA-SED); ROFA exposure, sedentary and supplemented (ROFA-SED-CrPic); ROFA exposure and trained (ROFA-AT); ROFA exposure, supplemented and trained (ROFA-AT-CrPic); sedentary (Sal-SED); sedentary and supplemented (Sal-SED-CrPic); trained (Sal-AT); and supplemented and trained (Sal-AT-CrPic). Rats exposed to ROFA (air pollution) received 50 µg of ROFA daily via intranasal instillation. Supplemented rats received CrPic (1 mg/kg/day) daily by oral gavage. Exercise training was performed on a rat treadmill (5×/week). Oxidative parameters were evaluated at the end of protocols. Trained groups demonstrated lower gain of body mass (P < .001) and increased exercise tolerance (P < .0001). In the gastrocnemius, trained groups demonstrated increased SOD activity (P < .0001) and decrease levels of TBARS (P = .0014), although CAT activity did not differ among groups (P = .4487). Air pollution exposure did not lead to alterations in oxidative markers in lungs and heart, and exercise training was responsible for decreasing oxidative stress of the gastrocnemius.

Calcium Carbonate Dissolution Above the Lysocline: Implications of Copepod Grazing on Coccolithophores

NASA Astrophysics Data System (ADS)

White, M. M.; Waller, J. D.; Lubelczyk, L.; Drapeau, D.; Bowler, B.; Wyeth, A.; Fields, D.; Balch, W. M.

2016-02-01

Copepod-coccolithophore predator-prey interactions are of great importance because they facilitate the export of particulate inorganic and organic carbon (PIC and POC) from the surface ocean. Coccolith dissolution in acidic copepod guts has been proposed as a possible explanation for the paradox of PIC dissolution above the lysocline, but warrants further investigation. Using a new application of the 14C-microdiffusion technique, we investigated the dissolution of coccoliths in copepod guts. We considered both an estuarine predator-prey model (Acartia tonsa and Pleurochrysis carterae) and an open ocean predator-prey model (Calanus finmarchicus and Emiliania huxleyi). Additionally, we considered the impacts of pCO2 on this process to advance our understanding of the effects of ocean acidification on trophic interactions. In the estuarine predator-prey model, fecal pellets produced immediately after previously-starved copepods grazed on P. carterae had PIC/POC ratios 27-40 % lower than that of the algae, indicating PIC dissolution within the copepod gut, with no impact of pCO2 on this dissolution. Subsequent fecal pellets showed increasing PIC/POC, suggesting that calcite dissolution decreases as the gut fills. The open ocean predator-prey model showed equivocal results, indicating high variability among individual grazing behavior, and therefore no consistent impact of copepod grazing on coccolith dissolution above the lysocline in the open ocean. We will further discuss the effects of fecal pellet PIC/POC ratios on sinking rate.

Triple bag hermetic technology for controlling a bruchid (Spermophagus sp.) (Coleoptera, Chrysomelidae) in stored Hibiscus sabdariffa grain.

PubMed

Amadou, L; Baoua, I B; Baributsa, D; Williams, S B; Murdock, L L

2016-10-01

We assessed the performance of hermetic triple layer Purdue Improved Crop Storage (PICS) bags for protecting Hibiscus sabdariffa grain against storage insects. The major storage pest in the grain was a bruchid, Spermophagus sp.. When we stored infested H. sabdariffa grain for six months in the woven polypropylene bags typically used by farmers, the Spermophagus population increased 33-fold over that initially present. The mean number of emergence holes per 100 seeds increased from 3.3 holes to 35.4 holes during this time period, while grain held for the same length of time in PICS bags experienced no increase in the numbers of holes. Grain weight loss in the woven control bags was 8.6% while no weight loss was observed in the PICS bags. Seed germination rates of grain held in woven bags for six months dropped significantly while germination of grain held in PICS bags did not change from the initial value. PICS bags can be used to safely store Hibiscus grain after harvest to protect against a major insect pest.

TWANG-PIC, a novel gyro-averaged one-dimensional particle-in-cell code for interpretation of gyrotron experiments

NASA Astrophysics Data System (ADS)

Braunmueller, F.; Tran, T. M.; Vuillemin, Q.; Alberti, S.; Genoud, J.; Hogge, J.-Ph.; Tran, M. Q.

2015-06-01

A new gyrotron simulation code for simulating the beam-wave interaction using a monomode time-dependent self-consistent model is presented. The new code TWANG-PIC is derived from the trajectory-based code TWANG by describing the electron motion in a gyro-averaged one-dimensional Particle-In-Cell (PIC) approach. In comparison to common PIC-codes, it is distinguished by its computation speed, which makes its use in parameter scans and in experiment interpretation possible. A benchmark of the new code is presented as well as a comparative study between the two codes. This study shows that the inclusion of a time-dependence in the electron equations, as it is the case in the PIC-approach, is mandatory for simulating any kind of non-stationary oscillations in gyrotrons. Finally, the new code is compared with experimental results and some implications of the violated model assumptions in the TWANG code are disclosed for a gyrotron experiment in which non-stationary regimes have been observed and for a critical case that is of interest in high power gyrotron development.

PIC simulations of conical magnetically insulated transmission line with LTD generator: Transition from self-limited to load-limited flow

NASA Astrophysics Data System (ADS)

Liu, Laqun; Wang, Huihui; Guo, Fan; Zou, Wenkang; Liu, Dagang

2017-04-01

Based on the 3-dimensional Particle-In-Cell (PIC) code CHIPIC3D, with a new circuit boundary algorithm we developed, a conical magnetically insulated transmission line (MITL) with a 1.0-MV linear transformer driver (LTD) is explored numerically. The values of switch jitter time of LTD are critical parameters for the system, which are difficult to be measured experimentally. In this paper, these values are obtained by comparing the PIC results with experimental data of large diode-gap MITL. By decreasing the diode gap, we find that all PIC results agree well with experimental data only if MITL works on self-limited flow no matter how large the diode gap is. However, when the diode gap decreases to a threshold, the self-limited flow would transfer to a load-limited flow. In this situation, PIC results no longer agree with experimental data anymore due to the anode plasma expansion in the diode load. This disagreement is used to estimate the plasma expansion speed.

Exposure of coastal built assets in the South Pacific to climate risks

NASA Astrophysics Data System (ADS)

Kumar, Lalit; Taylor, Subhashni

2015-11-01

Pacific island countries (PICs) are situated in a highly dynamic ocean-atmosphere interface, are dispersed over a large ocean area, and have highly populated urban centres located on the coastal margin. The built infrastructure associated with urban centres is also located within close proximity to the coastlines, exposing such infrastructure to a variety of natural and climate change-related hazards. In this research we undertake a comprehensive analysis of the exposure of built infrastructure assets to climate risk for 12 PICs. We show that 57% of the assessed built infrastructure for the 12 PICs is located within 500 m of their coastlines, amounting to a total replacement value of US$21.9 billion. Eight of the 12 PICs have 50% or more of their built infrastructure located within 500 m of their coastlines. In particular, Kiribati, Marshall Islands and Tuvalu have over 95% of their built infrastructure located within 500 m of their coastlines. Coastal adaptation costs will require substantial financial resources, which may not be available in developing countries such as the PICs, leaving them to face very high impacts but lacking the adaptive capacity.

Physical and chemical basics of modification of poly(vinyl chloride) by means of polyisocyanate

NASA Astrophysics Data System (ADS)

Islamov, Anvar; Fakhrutdinova, Venera; Abdrakhmanova, Lyailya

2016-01-01

This research presents data relating to polyvinyl chloride (PVC) modification by means of reactive oligomer and measures technological, physical and mechanical properties of the modified composites. Polyisocyanate (PIC) has been chosen as the modifying reactive oligomer. It has been shown that insertion of the oligomer has a double effect on PVC. Primarily, PIC produces a plasticizing effect on PVC and in particular leads to an increase in thermal stability and melt flow index at the stage of processing. In addition, the molded PVC composites possess higher strength properties and lower deformability when exposed to temperature because of chemical transformations of PIC in polymer matrix and, as the result, the formation of cross-linked systems takes place. In this case, semi-interpenetrating structures are formed based on cross-linked products of PIC chemical transformations homogeneously distributed in the PVC matrix. It has been determined by means of IR-spectroscopy that the basic products of PIC curing are compounds with urea and biuret groups which leads to modifying effect on PVC especially: increase in strength, thermal and mechanical properties, and chemical resistance.

Particle-In-Cell simulations of electron beam microbunching instability in three dimensions

NASA Astrophysics Data System (ADS)

Huang, Chengkun; Zeng, Y.; Meyers, M. D.; Yi, S.; Albright, B. J.; Kwan, T. J. T.

2013-10-01

Microbunching instability due to Coherent Synchrotron Radiation (CSR) in a magnetic chicane is one of the major effects that can degrade the electron beam quality in an X-ray Free Electron Laser. Self-consistent simulation using the Particle-In-Cell (PIC) method for the CSR fields of the beam and their effects on beam dynamics have been elusive due to the excessive dispersion error on the grid. We have implemented a high-order finite-volume PIC scheme that models the propagation of the CSR fields accurately. This new scheme is characterized and optimized through a detailed dispersion analysis. The CSR fields from our improved PIC calculation are compared to the extended CSR numerical model based on the Lienard-Wiechert formula in 2D/3D. We also conduct beam dynamics simulation of the microbunching instability using our new PIC capability. Detailed self-consistent PIC simulations of the CSR fields and beam dynamics will be presented and discussed. Work supported by the U.S. Department of Energy through the LDRD program at Los Alamos National Laboratory.

Overlap of copper and iron uptake systems in mitochondria in Saccharomyces cerevisiae

PubMed Central

Wang, Jing; Gammon, Micah G.; Maynard, Margaret K.; White, Olivia L.; Cobine, Jai A.; Mahone, Wilkerson K.

2016-01-01

In Saccharomyces cerevisiae, the mitochondrial carrier family protein Pic2 imports copper into the matrix. Deletion of PIC2 causes defects in mitochondrial copper uptake and copper-dependent growth phenotypes owing to decreased cytochrome c oxidase activity. However, copper import is not completely eliminated in this mutant, so alternative transport systems must exist. Deletion of MRS3, a component of the iron import machinery, also causes a copper-dependent growth defect on non-fermentable carbon. Deletion of both PIC2 and MRS3 led to a more severe respiratory growth defect than either individual mutant. In addition, MRS3 expressed from a high copy number vector was able to suppress the oxygen consumption and copper uptake defects of a strain lacking PIC2. When expressed in Lactococcus lactis, Mrs3 mediated copper and iron import. Finally, a PIC2 and MRS3 double mutant prevented the copper-dependent activation of a heterologously expressed copper sensor in the mitochondrial intermembrane space. Taken together, these data support a role for the iron transporter Mrs3 in copper import into the mitochondrial matrix. PMID:26763345

Numerical heating in Particle-In-Cell simulations with Monte Carlo binary collisions

NASA Astrophysics Data System (ADS)

Alves, E. Paulo; Mori, Warren; Fiuza, Frederico

2017-10-01

The binary Monte Carlo collision (BMCC) algorithm is a robust and popular method to include Coulomb collision effects in Particle-in-Cell (PIC) simulations of plasmas. While a number of works have focused on extending the validity of the model to different physical regimes of temperature and density, little attention has been given to the fundamental coupling between PIC and BMCC algorithms. Here, we show that the coupling between PIC and BMCC algorithms can give rise to (nonphysical) numerical heating of the system, that can be far greater than that observed when these algorithms operate independently. This deleterious numerical heating effect can significantly impact the evolution of the simulated system particularly for long simulation times. In this work, we describe the source of this numerical heating, and derive scaling laws for the numerical heating rates based on the numerical parameters of PIC-BMCC simulations. We compare our theoretical scalings with PIC-BMCC numerical experiments, and discuss strategies to minimize this parasitic effect. This work is supported by DOE FES under FWP 100237 and 100182.

Structures of transcription pre-initiation complex with TFIIH and Mediator.

PubMed

Schilbach, S; Hantsche, M; Tegunov, D; Dienemann, C; Wigge, C; Urlaub, H; Cramer, P

2017-11-09

For the initiation of transcription, RNA polymerase II (Pol II) assembles with general transcription factors on promoter DNA to form the pre-initiation complex (PIC). Here we report cryo-electron microscopy structures of the Saccharomyces cerevisiae PIC and PIC-core Mediator complex at nominal resolutions of 4.7 Å and 5.8 Å, respectively. The structures reveal transcription factor IIH (TFIIH), and suggest how the core and kinase TFIIH modules function in the opening of promoter DNA and the phosphorylation of Pol II, respectively. The TFIIH core subunit Ssl2 (a homologue of human XPB) is positioned on downstream DNA by the 'E-bridge' helix in TFIIE, consistent with TFIIE-stimulated DNA opening. The TFIIH kinase module subunit Tfb3 (MAT1 in human) anchors the kinase Kin28 (CDK7), which is mobile in the PIC but preferentially located between the Mediator hook and shoulder in the PIC-core Mediator complex. Open spaces between the Mediator head and middle modules may allow access of the kinase to its substrate, the C-terminal domain of Pol II.

TWANG-PIC, a novel gyro-averaged one-dimensional particle-in-cell code for interpretation of gyrotron experiments

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

Braunmueller, F., E-mail: falk.braunmueller@epfl.ch; Tran, T. M.; Alberti, S.

A new gyrotron simulation code for simulating the beam-wave interaction using a monomode time-dependent self-consistent model is presented. The new code TWANG-PIC is derived from the trajectory-based code TWANG by describing the electron motion in a gyro-averaged one-dimensional Particle-In-Cell (PIC) approach. In comparison to common PIC-codes, it is distinguished by its computation speed, which makes its use in parameter scans and in experiment interpretation possible. A benchmark of the new code is presented as well as a comparative study between the two codes. This study shows that the inclusion of a time-dependence in the electron equations, as it is themore » case in the PIC-approach, is mandatory for simulating any kind of non-stationary oscillations in gyrotrons. Finally, the new code is compared with experimental results and some implications of the violated model assumptions in the TWANG code are disclosed for a gyrotron experiment in which non-stationary regimes have been observed and for a critical case that is of interest in high power gyrotron development.« less

Conformation-Directed Formation of Self-Healing Diblock Copolypeptide Hydrogels via Polyion Complexation.

PubMed

Sun, Yintao; Wollenberg, Alexander L; O'Shea, Timothy Mark; Cui, Yanxiang; Zhou, Z Hong; Sofroniew, Michael V; Deming, Timothy J

2017-10-25

Synthetic diblock copolypeptides were designed to incorporate oppositely charged ionic segments that form β-sheet-structured hydrogel assemblies via polyion complexation when mixed in aqueous media. The observed chain conformation directed assembly was found to be required for efficient hydrogel formation and provided distinct and useful properties to these hydrogels, including self-healing after deformation, microporous architecture, and stability against dilution in aqueous media. While many promising self-assembled materials have been prepared using disordered or liquid coacervate polyion complex (PIC) assemblies, the use of ordered chain conformations in PIC assemblies to direct formation of new supramolecular morphologies is unprecedented. The promising attributes and unique features of the β-sheet-structured PIC hydrogels described here highlight the potential of harnessing conformational order derived from PIC assembly to create new supramolecular materials.

Finite grid instability and spectral fidelity of the electrostatic Particle-In-Cell algorithm

DOE PAGES

Huang, C. -K.; Zeng, Y.; Wang, Y.; ...

2016-10-01

The origin of the Finite Grid Instability (FGI) is studied by resolving the dynamics in the 1D electrostatic Particle-In-Cell (PIC) model in the spectral domain at the single particle level and at the collective motion level. The spectral fidelity of the PIC model is contrasted with the underlying physical system or the gridless model. The systematic spectral phase and amplitude errors from the charge deposition and field interpolation are quantified for common particle shapes used in the PIC models. Lastly, it is shown through such analysis and in simulations that the lack of spectral fidelity relative to the physical systemmore » due to the existence of aliased spatial modes is the major cause of the FGI in the PIC model.« less

Proceedings of the 14th International Conference on the Numerical Simulation of Plasmas

NASA Astrophysics Data System (ADS)

Partial Contents are as follows: Numerical Simulations of the Vlasov-Maxwell Equations by Coupled Particle-Finite Element Methods on Unstructured Meshes; Electromagnetic PIC Simulations Using Finite Elements on Unstructured Grids; Modelling Travelling Wave Output Structures with the Particle-in-Cell Code CONDOR; SST--A Single-Slice Particle Simulation Code; Graphical Display and Animation of Data Produced by Electromagnetic, Particle-in-Cell Codes; A Post-Processor for the PEST Code; Gray Scale Rendering of Beam Profile Data; A 2D Electromagnetic PIC Code for Distributed Memory Parallel Computers; 3-D Electromagnetic PIC Simulation on the NRL Connection Machine; Plasma PIC Simulations on MIMD Computers; Vlasov-Maxwell Algorithm for Electromagnetic Plasma Simulation on Distributed Architectures; MHD Boundary Layer Calculation Using the Vortex Method; and Eulerian Codes for Plasma Simulations.

Finite grid instability and spectral fidelity of the electrostatic Particle-In-Cell algorithm

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

Huang, C. -K.; Zeng, Y.; Wang, Y.

The origin of the Finite Grid Instability (FGI) is studied by resolving the dynamics in the 1D electrostatic Particle-In-Cell (PIC) model in the spectral domain at the single particle level and at the collective motion level. The spectral fidelity of the PIC model is contrasted with the underlying physical system or the gridless model. The systematic spectral phase and amplitude errors from the charge deposition and field interpolation are quantified for common particle shapes used in the PIC models. Lastly, it is shown through such analysis and in simulations that the lack of spectral fidelity relative to the physical systemmore » due to the existence of aliased spatial modes is the major cause of the FGI in the PIC model.« less

Thirty years of beta Pic and debris disks studies

NASA Astrophysics Data System (ADS)

Lagrange, Anne-Marie; Boccaletti, Anthony

2015-01-01

In the last 30 years, our knowledge of planetary systems has considerably evolved, in particular thanks to the development of observational techniques and computer simulations for modeling. From the observational point of view, emblematic discoveries thirty years ago have opened a way to dedicated studies, among which the IRAS detections of IR excess associated to dust surrounding main-sequence stars. Shortly after these discoveries, the first image of a debris disk around the star beta Pictoris in 1984 was made, followed in the 90's by the indirect detection of extrasolar planets and, a decade later, by the direct imaging of young giant planets. Beta Pictoris is a ground-breaking object for the study of formation and evolution of planetary systems. It is a unique system in many regards, as it is made of dust, planetesimals, comets and at least one giant planet. Observations with various techniques (imaging, spectroscopy, interferometry) at multiple wavelengths (from the UV to radio waves) have allowed significant progress in the understanding of this system. Yet, many questions are still open, and more results are expected in the coming decade thanks to the next generation of instruments like for instance ALMA, JWST, SPHERE and many others. To celebrate the thirtieth anniversary of the first debris disk image, we propose to gather experts on the analysis of beta Pictoris and interested colleagues to review and discuss the observational knowledge on this archetypal system (including the latest results), as well as its current understanding and related open questions to be addressed in the next decade, such as the history of the disk and planet formation, dynamical evolution, etc. Similar, well-studied debris disks systems with significant amount of observational data that allow in-depth modeling will be also presented and discussed. Second, in a two-days dedicated workshop, we will gather to define an action plan for the typically 3-5 next years to achieve a full, comprehensive description of the whole beta Pictoris system, and to organize the necessary work, and possible milestones. In the next years, a similar approach may, eventually, be applicable to other systems.

Thirty years of beta Pic and debris disks studies

NASA Astrophysics Data System (ADS)

Lagrange, A.-M.; Boccaletti, A.

2014-09-01

In the last 30 years, our knowledge of planetary systems has considerably evolved, in particular thanks to the development of observational techniques and computer simulations for modeling. From the observational point of view, emblematic discoveries thirty years ago have opened a way to dedicated studies, among which the IRAS detections of IR excess associated to dust surrounding main-sequence stars. Shortly after these discoveries, the first image of a debris disk around the star beta Pictoris in 1984 was made, followed in the 90's by the indirect detection of extrasolar planets and, a decade later, by the direct imaging of young giant planets. Beta Pictoris is a ground-breaking object for the study of formation and evolution of planetary systems. It is a unique system in many regards, as it is made of dust, planetesimals, comets and at least one giant planet. Observations with various techniques (imaging, spectroscopy, interferometry) at multiple wavelengths (from the UV to radio waves) have allowed significant progress in the understanding of this system. Yet, many questions are still open, and more results are expected in the coming decade thanks to the next generation of instruments like for instance ALMA, JWST, SPHERE and many others. To celebrate the thirtieth anniversary of the first debris disk image, we propose to gather experts on the analysis of beta Pictoris and interested colleagues to review and discuss the observational knowledge on this archetypal system (including the latest results), as well as its current understanding and related open questions to be addressed in the next decade, such as the history of the disk and planet formation, dynamical evolution, etc. Similar, well-studied debris disks systems with significant amount of observational data that allow in-depth modeling will be also presented and discussed. Second, in a two-days dedicated workshop, we will gather to define an action plan for the typically 3-5 next years to achieve a full, comprehensive description of the whole beta Pictoris system, and to organize the necessary work, and possible milestones. In the next years, a similar approach may, eventually, be applicable to other systems.

Reexamination of the Coronal Index of Solar Activity

DTIC Science & Technology

2005-08-25

data with measurements made at Pic du Midi and Arosa . The resultant 1939-1992 CI had the interesting property that its value at the peak of the 11-year...1939 observation of the coronal emission line at 5303 A during when Waldmeier initiated green line measurements at Arosa the total solar eclipse of 7...limitations since the values obtained at differ- and Pic du Midi and Pic du Midi and Arosa to extend ent observatories depend on: (1) the accuracy of the the

Regulation of organic nucleic acids and serum biochemistry parameters by dietary chromium picolinate supplementation in swine model.

PubMed

Jiajun, Yang; Aiyun, Han; Shanshan, Zheng; Minhong, Zhang

2011-04-01

The relationships between chromium and metabolism are sophisticated. Organic nucleic acids and serum biochemistry parameters are affected by dietary chromium levels. The objective of this work was to study the effect of chromium picolinate (CrPic) supplementation on total DNA and RNA contents, the ratio of RNA/DNA in muscle and in pancreatic tissue, the level of insulin receptor (IR) mRNA and some serum biochemistry parameters in a porcine model. Young animals (48) were assigned randomly into three groups of 16 piglets, fed with three different dietary levels of Cr (common basal feedstuff alone or supplemented with CrPic at a dose of 1.61 μg/g or 3.22 μg/g, which corresponds to 0.2 μg/g and 0.4 μg/g Cr). After 80 days, the animals were sacrificed and skeletal muscle and pancreatic tissues were analyzed to detect differences caused by different levels of dietary Cr. The total content of RNA in muscle was increased significantly (P<0.05) in the CrPic supplemented groups. There was no significant difference between groups in the concentrations of total RNA in the pancreas or DNA in the muscle and pancreatic tissues. The RNA/DNA ratio in pancreas showed no significant change but the ratio was increased significantly (P<0.05) in muscle. There was a slight increase of the mRNA level of IR but there was no significant difference between groups. The content of serum cholesterol and insulin were reduced significantly (P<0.05) in the CrPic-supplemented groups and the content of high-density lipoprotein cholesterol (HDLC) was increased significantly (P<0.05) as the CrPic dose increased. There was a slight (non-significant) reduction of the concentrations of serum triglyceride and low-density lipoprotein cholesterol (LDLC) in the CrPic supplementation groups. Supplementary CrPic caused no significant change of muscular mRNA level of IR in healthy animals. An increased content of RNA in muscle, improved cholesterol metabolism and improved insulin sensitivity were found in these CrPic-treated groups in the porcine model. Copyright © 2011 Elsevier GmbH. All rights reserved.

A simple and specific high performance liquid chromatography method for the assay of a series of novel dermal penetration enhancers.

PubMed

Michniak, B B; Seyda, K L

1993-02-01

Synopsis A series of clofibric acid amides has been synthesized and previously reported by the authors as possessing enhancer activity in vitro in athymic nude mouse skin against model drugs, hydrocortisone-21-acetate and beta-methasone-17-valerate. An assay was required for each of these enhancers however, which would be specific for each compound and would also separate model drugs and their metabolite peaks. This study reports reverse phase high performance liquid chromatography assays for clofibric acid amide and seven derivatives (Ia-Ig). All enhancers showed maximum absorption at 232 nm, betamethasone (BM) and its valerate (BMV) at 238 nm, and hydrocortisone (HC) and its acetate (HCA) at 242 nm. Practical units of detection for the amides were 0.46-2.8 mug ml(-1) and peaks were sharp and well-separated from steroid peaks in three vehicles - methanol alone. Franz diffusion cell receptor phase samples (isotonic phosphate buffer), and full-thickness athymic nude mouse skin extracts in methanol. Mobile phases consisted of various proportions of acetonitrile and water, some with 2-propanol. The octyl amide for example, with mobile phase CH(3)CN: H(2)O (85:15) at 1 ml min(-1) had a retention time (t(R)) of 7.9 mins. Under the same conditions, retention times for the steroids were HC, t(R)= 3.3 mins; HCA, t(R)= 4.3 mins; BM, t(R)= 3.4 mins; BMV, t(R)= 4.6 mins. Résumé Les auteurs avaient démontré dans un article précédent le pouvoir accélérateur de pénétration dermique in vitro d'une gamme d'amides d'acide clofibrique sur la peau de souris sans poils, et sans thymus avec des médicaments types tels que l'acetate 21 d'hydrocortisone et le valerate 17 de beta-metasone. Il a cependant été requis, pour chacun de ces accélérateurs, un test spécifique pour chaque composition, permettant de séparer chaque médicament et les pics des métabolites. Cette étude décrit des tests par chromatographie liquide à haute performance en phase inverse pour l'acide chlofibrique et 7 dérivés (Ia-Ig). Tous les accélérateurs ont montré une absorption maximale à 232 nm, la beta-metasone (BM) et son valerate (BMV) à 238 nm, l'hydrocortisone (HC) et son acetate (HCA) à 242 nm. Les unités de détection s'élevaient à 0.46-2.8 mug ml(-1) pour les amides et les pics étaient aigus et distincts des pics stéroïdes et se composaient de 3 véhicules - le méthanol seul, des échantillons du récepteur de cellule de diffusion Franz (tampon du phosphate isotonique) et des extraits de peau de souris sans thymus dans du méthanol. Les phases mobiles étaient constituées de différentes proportions d'acetonitrile et d'eau, certaines avec du propanol-2. L'amide octyl par exemple, avec une phase mobile CH(3)CN: H(2)O (85:15) à 1 ml min(-1) avait un temps de rétention (t(R)) de 7.9 min. Dans des conditions identiques, les temps de rétention pour les stéroïdes étaient les suivants: pour HC, t(R)= 3.3 mins; pour HCA, t(R)= 4.3 mins; pour BM: t(R)= 3.4 mins; pour BMV: t(R)= 4.6 mins.

Effects of beta-phenylethylamine on dopaminergic neurons of the ventral tegmental area in the rat: a combined electrophysiological and microdialysis study.

PubMed

Ishida, Kota; Murata, Mikio; Katagiri, Nobuyuki; Ishikawa, Masago; Abe, Kenji; Kato, Masatoshi; Utsunomiya, Iku; Taguchi, Kyoji

2005-08-01

The effects of systemic administration of beta-phenylethylamine (beta-PEA) and microiontophoretically applied beta-PEA on the spontaneous discharge of dopamine (DA) neurons in the ventral tegmental area (VTA) of the anesthetized rat were examined. Intravenous administration of beta-PEA (1.0, 2.5, and 5.0 mg/kg) and microiontophoretic applications of beta-PEA caused inhibitory responses in DA neurons. Systemic administration and microiontophoretic applications of beta-PEA induced dose- or current-dependent responses. The systemic beta-PEA-induced inhibitory responses were reversed by pretreatment with the DA D(2) receptor antagonists haloperidol (0.5 mg/kg i.p.) and sulpiride (10 mg/kg i.p). Pretreatment with reserpine (5 mg/kg i.p. 24 h earlier) did not completely block the systemic administration of beta-PEA (2.5 mg/kg) inhibition. A microdialysis study of freely moving rats demonstrated that the extracellular DA level increased significantly in response to local application of beta-PEA (100 muM) in the VTA via a microdialysis probe, and local application of beta-PEA-stimulated somatodendritic DA release in the VTA. The beta-PEA-induced release of DA was calcium ion-independent and was enhanced by pretreatment with pertussis toxin. These findings indicate that beta-phenylethylamine inhibits DA neuron activity via DA D(2) autoreceptors in the rat VTA and that this inhibitory effect is mediated by the somatodendritic DA release.

76 FR 2084 - Pacific Fishery Management Council; Public Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-12

... Pacific Fishery Management Council's (Council) Ad Hoc Groundfish Process Improvement Committee (PIC) will... the PIC work session is to develop an optimum detailed process and schedule for the 2013-14 groundfish...

Flip-chip integration of tilted VCSELs onto a silicon photonic integrated circuit.

PubMed

Lu, Huihui; Lee, Jun Su; Zhao, Yan; Scarcella, Carmelo; Cardile, Paolo; Daly, Aidan; Ortsiefer, Markus; Carroll, Lee; O'Brien, Peter

2016-07-25

In this article we describe a cost-effective approach for hybrid laser integration, in which vertical cavity surface emitting lasers (VCSELs) are passively-aligned and flip-chip bonded to a Si photonic integrated circuit (PIC), with a tilt-angle optimized for optical-insertion into standard grating-couplers. A tilt-angle of 10° is achieved by controlling the reflow of the solder ball deposition used for the electrical-contacting and mechanical-bonding of the VCSEL to the PIC. After flip-chip integration, the VCSEL-to-PIC insertion loss is -11.8 dB, indicating an excess coupling penalty of -5.9 dB, compared to Fibre-to-PIC coupling. Finite difference time domain simulations indicate that the penalty arises from the relatively poor match between the VCSEL mode and the grating-coupler.

Forced Reconnection in the Near Magnetotail: Onset and Energy Conversion in PIC and MHD Simulations

NASA Technical Reports Server (NTRS)

Birn, J.; Hesse, Michael

2014-01-01

Using two-dimensional particle-in-cell (PIC) together with magnetohydrodynamic (MHD) Q1 simulations of magnetotail dynamics, we investigate the evolution toward onset of reconnection and the subsequent energy transfer and conversion. In either case, reconnection onset is preceded by a driven phase, during which magnetic flux is added to the tail at the high-latitude boundaries, followed by a relaxation phase, during which the configuration continues to respond to the driving. The boundary deformation leads to the formation of thin embedded current sheets, which are bifurcated in the near tail, converging to a single sheet farther out in the MHD simulations. The thin current sheets in the PIC simulation are carried by electrons and are associated with a strong perpendicular electrostatic field, which may provide a connection to parallel potentials and auroral arcs and an ionospheric signal even prior to the onset of reconnection. The PIC simulation very well satisfies integral entropy conservation (intrinsic to ideal MHD) during this phase, supporting ideal ballooning stability. Eventually, the current intensification leads to the onset of reconnection, the formation and ejection of a plasmoid, and a collapse of the inner tail. The earthward flow shows the characteristics of a dipolarization front: enhancement of Bz, associated with a thin vertical electron current sheet in the PIC simulation. Both MHD and PIC simulations show a dominance of energy conversion from incoming Poynting flux to outgoing enthalpy flux, resulting in heating of the inner tail. Localized Joule dissipation plays only a minor role.

Antimicrobial activities, DNA interactions, spectroscopic (FT-IR and UV-Vis) characterizations, and DFT calculations for pyridine-2-carboxylic acid and its derivates

NASA Astrophysics Data System (ADS)

Tamer, Ömer; Tamer, Sevil Arabacı; İdil, Önder; Avcı, Davut; Vural, Hatice; Atalay, Yusuf

2018-01-01

In this paper, pyridine- 2- carboxylic acid, also known as picolinic acid (pic), and its two derivate, 4- methoxy-pyridine- 2- carboxylic acid (4-Mpic) and 4- chloro-pyridine- 2- carboxylic acid (4-Clpic) have been characterized by FT-IR and UV-Vis spectroscopy techniques as well as DFT calculations. B3LYP level of Density Functional Theory (DFT) method was used to obtain ground state geometries, vibration wavenumbers, first order hyperpolarizabilities and molecular electrostatic potential (MEP) surfaces for pic, 4Clpic and 4Mpic. The electronic absorption wavelengths and HOMO-LUMO energies were investigated by time dependent B3LYP (TD-B3LYP) level with the conductor-like polarizable continuum model (CPCM). The effects of Cl atom and OCH3 group on HOMO-LUMO energy gaps and first order hyperpolarizability parameters of pic, 4Clpic and 4Mpic molecules were examined. All molecules were screened for their antibacterial activities against Gram-positive and Gram-negative bacteria and for their antifungal activities against yeast strains by using minimal inhibitory concentration method (MIC). All compounds (pic, 4Mpic and 4Clpic) have been found to be very active against to the Gram (+) and Gram (-) bacteria. The DNA interactions of pic, 4Clpic and 4Mpic were analyzed by molecular docking simulations, and the interaction of the 4Mpic molecule with DNA is found to be higher than 4Clpic and pic.

Chromium picolinate and chromium histidinate protects against renal dysfunction by modulation of NF-κB pathway in high-fat diet fed and Streptozotocin-induced diabetic rats.

PubMed

Selcuk, Mustafa Yavuz; Aygen, Bilge; Dogukan, Ayhan; Tuzcu, Zeynep; Akdemir, Fatih; Komorowski, James R; Atalay, Mustafa; Sahin, Kazim

2012-04-08

Diabetic nephropathy is one of major complications of diabetes mellitus. Although chromium is an essential element for carbohydrate and lipid metabolism, its effects on diabetic nephropathy are not well understood. The present study was conducted to investigate the effects of chromium picolinate (CrPic) and chromium histidinate (CrHis) on nuclear factor-kappa B (NF-κB) and nuclear factor-E2-related factor-2 (Nrf2) pathway in the rat kidney. Male Wistar rats were divided into six groups. Group I received a standard diet (8% fat) and served as a control; Group II was fed with a standard diet and received CrPic; Group III was fed with a standard diet and received CrHis; Group IV received a high fat diet (HFD, 40% fat) for 2 weeks and then were injected with streptozotocin (STZ) (HFD/STZ); Group V was treated as group IV (HFD/STZ) but supplemented with CrPic for 12 weeks. Group VI was treated as group IV (HFD/STZ) but supplemented with CrHis. The increased NF-κβ p65 in the HFD/STZ group was inhibited by CrPic and CrHis supplementation (P < 0.05). In STZ-treated rats, a significant decrease in levels of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα) was found in kidney tissues when compared to control rats (P < 0.05). A significant increase in the levels of IκBα was observed in CrPic- and CrHis-treated rats when compared with STZ-treated rats. Renal Nrf2 levels were significantly decreased in diabetic rats compared with the control rats. There was a higher tendency for increase of kidney Nrf2 level and decrease in kidney NFκBp65 levels and 4- hydroxyl nonenal (4-HNE) protein adducts (P < 0.05) in diabetic rats. Our result show that in kidney tissue CrHis/CrPic increases Nrf2 level, parallelly decreases NF-κB and partially restores IκBα levels in HFD/STZ group, suggesting that CrPic and CrHis may play a role in antioxidant defense system via the Nrf2 pathway by reducing inflammation through NF-κβ p65 inhibition. Moreover, a greater reduction in NF-κB expression and greater increases in expressions of IκBα and Nrf2 in diabetic rats supplemented with CrHis than rats supplemented with CrPic suggest that CrHis has more favorable effects than CrPic.

Electron Heating by the Ion Cyclotron Instability in Collisionless Accretion Flows. I. Compression-driven Instabilities and the Electron Heating Mechanism

NASA Astrophysics Data System (ADS)

Sironi, Lorenzo; Narayan, Ramesh

2015-02-01

In systems accreting well below the Eddington rate, such as the central black hole in the Milky Way (Sgr A*), the plasma in the innermost regions of the disk is believed to be collisionless and have two temperatures, with the ions substantially hotter than the electrons. However, whether a collisionless faster-than-Coulomb energy transfer mechanism exists in two-temperature accretion flows is still an open question. We study the physics of electron heating during the growth of ion velocity-space instabilities by means of multidimensional, fully kinetic, particle-in-cell (PIC) simulations. A background large-scale compression—embedded in a novel form of the PIC equations—continuously amplifies the field. This constantly drives a pressure anisotropy P > P ∥ because of the adiabatic invariance of the particle magnetic moments. We find that, for ion plasma beta values β0i ~ 5-30 appropriate for the midplane of low-luminosity accretion flows (here, β0i is the ratio of ion thermal pressure to magnetic pressure), mirror modes dominate if the electron-to-proton temperature ratio is T 0e /T 0i >~ 0.2, whereas for T 0e /T 0i <~ 0.2 the ion cyclotron instability triggers the growth of strong Alfvén-like waves, which pitch-angle scatter the ions to maintain marginal stability. We develop an analytical model of electron heating during the growth of the ion cyclotron instability, which we validate with PIC simulations. We find that for cold electrons (β0e <~ 2 me /mi , where β0e is the ratio of electron thermal pressure to magnetic pressure), the electron energy gain is controlled by the magnitude of the E-cross-B velocity induced by the ion cyclotron waves. This term is independent of the initial electron temperature, so it provides a solid energy floor even for electrons starting with extremely low temperatures. On the other hand, the electron energy gain for β0e >~ 2 me /mi —governed by the conservation of the particle magnetic moment in the growing fields of the instability—is proportional to the initial electron temperature, and it scales with the magnetic energy of ion cyclotron waves. Our results have implications for two-temperature accretion flows as well as for solar wind and intracluster plasmas.

Constitutive turnover of histone H2A.Z at yeast promoters requires the preinitiation complex

PubMed Central

Tramantano, Michael; Sun, Lu; Au, Christy; Labuz, Daniel; Liu, Zhimin; Chou, Mindy; Shen, Chen; Luk, Ed

2016-01-01

The assembly of the preinitiation complex (PIC) occurs upstream of the +1 nucleosome which, in yeast, obstructs the transcription start site and is frequently assembled with the histone variant H2A.Z. To understand the contribution of the transcription machinery in the disassembly of the +1 H2A.Z nucleosome, conditional mutants were used to block PIC assembly. A quantitative ChIP-seq approach, which allows detection of global occupancy change, was employed to measure H2A.Z occupancy. Blocking PIC assembly resulted in promoter-specific H2A.Z accumulation, indicating that the PIC is required to evict H2A.Z. By contrast, H2A.Z eviction was unaffected upon depletion of INO80, a remodeler previously reported to displace nucleosomal H2A.Z. Robust PIC-dependent H2A.Z eviction was observed at active and infrequently transcribed genes, indicating that constitutive H2A.Z turnover is a general phenomenon. Finally, sites with strong H2A.Z turnover precisely mark transcript starts, providing a new metric for identifying cryptic and alternative sites of initiation. DOI: http://dx.doi.org/10.7554/eLife.14243.001 PMID:27438412

Prediction impact curve is a new measure integrating intervention effects in the evaluation of risk models.

PubMed

Campbell, William; Ganna, Andrea; Ingelsson, Erik; Janssens, A Cecile J W

2016-01-01

We propose a new measure of assessing the performance of risk models, the area under the prediction impact curve (auPIC), which quantifies the performance of risk models in terms of their average health impact in the population. Using simulated data, we explain how the prediction impact curve (PIC) estimates the percentage of events prevented when a risk model is used to assign high-risk individuals to an intervention. We apply the PIC to the Atherosclerosis Risk in Communities (ARIC) Study to illustrate its application toward prevention of coronary heart disease. We estimated that if the ARIC cohort received statins at baseline, 5% of events would be prevented when the risk model was evaluated at a cutoff threshold of 20% predicted risk compared to 1% when individuals were assigned to the intervention without the use of a model. By calculating the auPIC, we estimated that an average of 15% of events would be prevented when considering performance across the entire interval. We conclude that the PIC is a clinically meaningful measure for quantifying the expected health impact of risk models that supplements existing measures of model performance. Copyright © 2016 Elsevier Inc. All rights reserved.

Dietary Supplementation with Chromium Picolinate Influences Serum Glucose and Immune Response of Brown-Egg Laying Hens.

PubMed

Zhang, Shumin; Sun, Xiaoming; Liao, Xiudong; Lu, Lin; Zhang, Liyang; Ma, Qiugang; Luo, Xugang

2018-01-29

To investigate the effect of chromium picolinate (CrPic) on egg production performance, egg quality, blood indices, and immune function of laying hens, 270 23-week-old Beijing Red brown-egg laying hens were randomly assigned to one of three treatments with six replicates of 15 birds per replicate for each treatment in a completely randomized design. Laying hens were fed a Cr-unsupplemented corn-soybean meal basal diet (control, containing 0.45 mg Cr/kg by analysis) or the basal diet supplemented with 0.4 or 0.6 mg Cr/kg from CrPic for 10 weeks. Laying hens fed diets supplemented with CrPic had a lower (P < 0.05) serum glucose (GLU) concentration and higher (P < 0.03) serum antibody titer against Newcastle disease than those fed the control diet at 33 weeks of age. However, supplemental CrPic had no effect (P > 0.05) on egg production and egg quality of brown-egg laying hens from 24 to 33 weeks of age. The results from this study indicated that supplemental CrPic decreased serum GLU and enhanced the immune function of brown-egg laying hens.

Tissue accumulation and urinary excretion of Cr in chromium picolinate (CrPic)-supplemented lambs.

PubMed

Dallago, Bruno Stéfano Lima; Lima, Bárbara Alcântara Ferreira; Braz, Shélida Vasconcelos; Mustafa, Vanessa da Silva; McManus, Concepta; Paim, Tiago do Prado; Campeche, Aline; Gomes, Edgard Franco; Louvandini, Helder

2016-05-01

Chromium (Cr) concentrations in liver, kidney, spleen, heart, lymph node, skeletal muscle, bone, testis and urine of lambs were measured to trace the biodistribution and bioaccumulation of Cr after oral supplementation with chromium picolinate (CrPic). Twenty-four Santa Inês lambs were treated with four different concentrations of CrPic: placebo, 0.250, 0.375 and 0.500 mg of CrPic/animal/day for 84 days. The basal diet consisted of Panicum maximum cv Massai hay and concentrate. Cr concentrations were measured by ICP-MS measuring (52)Cr as collected mass. There was a positive linear relationship between dose administered and the accumulation of Cr in the heart, lungs and testis. Urinary excretion of Cr occurred in a time and dose-dependent manner, so the longer or more dietary Cr provided, the greater excretion of the element. As some non-carcass components (such as lungs or heart) are added to bone and visceral meal to feed animals, there is a risk of bioaccumulation and biomagnification due to Cr offered as CrPic in the diet. Copyright © 2016 Elsevier GmbH. All rights reserved.

Evaluation of the Main Ceos Pseudo Calibration Sites Using Modis Brdf/albedo Products

NASA Astrophysics Data System (ADS)

Kharbouche, Said; Muller, Jan-Peter

2016-06-01

This work describes our findings about an evaluation of the stability and the consistency of twenty primary PICSs (Pseudo-Invariant Calibration Sites). We present an analysis of 13 years of 8-daily MODIS products of BRDF parameters and white-sky-albedos (WSA) over the shortwave band. This time series of WSA and BRDFs shows the variation of the "stability" varies significantly from site to site. Using a 10x10 km window size over all the sites, the change in of WSA stability is around 4% but the isotropicity, which is an important element in inter-satellite calibration, can vary from 75% to 98%. Moreover, some PICS, especially, Libya-4 which is one of the PICS which is most employed, has significant and relatively fast changes in wintertime. PICS observations of BRDF/albedo shows that the Libya-4 PICS has the best performance but it is not too far from some sites such as Libya-1 and Mali. This study also reveals that Niger-3 PICS has the longest continuous period of high stability per year, and Sudan has the most isotropic surface. These observations have important implications for the use of these sites.

Upper limit on magnetic monopole flux from Baksan experiment

NASA Technical Reports Server (NTRS)

Alexeyev, E. N.; Boliev, M. M.; Chudakov, A. E.; Mikheyev, S. P.

1985-01-01

No indication of slowly moving penetrating particles in cosmic radiation underground was found during two years observation. Particle velocity and pulse shape are main criteria for search. Probability of the imitation of slow particles (Beta 0.1) by atmospheric muons is negligible. Our upper limit on superheavy magnetic monopole flux is now 1.86 x 10 to the minus 15th power cm(-2) sr(-1) s(-1) (90% c.l.) for velocity range 2 x 0.0001 beta 0.1.

A wireless beta-microprobe based on pixelated silicon for in vivo brain studies in freely moving rats

NASA Astrophysics Data System (ADS)

Märk, J.; Benoit, D.; Balasse, L.; Benoit, M.; Clémens, J. C.; Fieux, S.; Fougeron, D.; Graber-Bolis, J.; Janvier, B.; Jevaud, M.; Genoux, A.; Gisquet-Verrier, P.; Menouni, M.; Pain, F.; Pinot, L.; Tourvielle, C.; Zimmer, L.; Morel, C.; Laniece, P.

2013-07-01

The investigation of neurophysiological mechanisms underlying the functional specificity of brain regions requires the development of technologies that are well adjusted to in vivo studies in small animals. An exciting challenge remains the combination of brain imaging and behavioural studies, which associates molecular processes of neuronal communications to their related actions. A pixelated intracerebral probe (PIXSIC) presents a novel strategy using a submillimetric probe for beta+ radiotracer detection based on a pixelated silicon diode that can be stereotaxically implanted in the brain region of interest. This fully autonomous detection system permits time-resolved high sensitivity measurements of radiotracers with additional imaging features in freely moving rats. An application-specific integrated circuit (ASIC) allows for parallel signal processing of each pixel and enables the wireless operation. All components of the detector were tested and characterized. The beta+ sensitivity of the system was determined with the probe dipped into radiotracer solutions. Monte Carlo simulations served to validate the experimental values and assess the contribution of gamma noise. Preliminary implantation tests on anaesthetized rats proved PIXSIC's functionality in brain tissue. High spatial resolution allows for the visualization of radiotracer concentration in different brain regions with high temporal resolution.

Modeling Resonant Structure in the Kuiper Belt

NASA Astrophysics Data System (ADS)

Holmes, E. K.; Dermott, S. F.; Grogan, K.

1999-09-01

There is a possible connection between structure in circumstellar disks and the presence of planets, our own zodiacal cloud being the prime example. Asymmetries in such a disk could be diagnostic of planets which would be otherwise undetectable. At least three different types of asymmetries can serve to indicate bodies orbiting a star in a disk: (1) a warp in the plane of symmetry of the disk, (2) an offset in the center of symmetry of the disk with respect to the central star, and (3) density anomalies in the plane of the disk due to resonant trapping of dust particles. In the asteroid belt, collisions between asteroids supply dust particles to the zodiacal cloud. By comparison, it has been postulated that collisions between KBOs could initiate a collisional cascade which would produce a Kuiper dust disk. In fact, the Kuiper Belt is the region of our solar system that is most analogous to the planetary debris disks we see around other stars such as Vega, beta Pic, Fomalhaut, and epsilon Eridani (Backman and Paresce 1993). A Kuiper Disk would most likely have a resonant structure, with two concentrations in brightness along the ecliptic longitude. This large scale structure arises because many of the KBOs, the Plutinos, are in the 2:3 mean motion resonance with Neptune. By running numerical integrations of particles in Pluto-like orbits, the resonant structure of the Kuiper belt can be studied by determining the percentage of particles trapped in the resonance as a function of their initial velocity and beta, where beta = Frad/Fgrav. The dynamical evolution of the particles is followed from source to sink with Poynting Robertson light drag, solar wind drag, radiation pressure, and the effects of planetary gravitational perturbations included. This research was funded in part by a NASA GSRP grant.

Pharmacological and biochemical analysis of FPL 67156, a novel, selective inhibitor of ecto-ATPase.

PubMed Central

Crack, B E; Pollard, C E; Beukers, M W; Roberts, S M; Hunt, S F; Ingall, A H; McKechnie, K C; IJzerman, A P; Leff, P

1995-01-01

1. FPL 67156 (6-N,N-diethyl-beta, gamma-dibromomethylene-D-ATP), is a newly synthesized analogue of ATP. 2. In a rabbit isolated tracheal epithelium preparation, measuring P2U-purinoceptor-dependent chloride secretion, FPL 67156 was discovered to potentiate the responses to UTP but not those to ATP-gamma-S. UTP agonist-concentration effect (E/[A]) curves were shifted to the left by 5-fold in the presence of 100 microM FPL 67156. The differential effect of FPL 67156 on UTP and ATP-gamma-S was hypothesized to be due to the greater susceptibility of UTP to enzymatic dephosphorylation and the ability of FPL 67156 to inhibit this process. 3. FPL 67156 was tested as an ecto-ATPase inhibitor in a human blood cell assay, measuring [gamma 32P]-ATP dephosphorylation. The compound inhibited [gamma 32P]-ATP degradation with a pIC50 of 4.6. 4. FPL 67156 was then tested for its effects on ATP and alpha, beta-methylene-ATP responses at P2X-purinoceptors in the rabbit isolated ear artery. In the concentration range 30 microM-1 mM, the compound potentiated the contractile effects of ATP but not those of alpha, beta-methylene-ATP. At 1 mM, FPL 67156 produced a 34-fold leftward shift of ATP E/[A] curves. 5. The effects of FPL 67156 on ATP E/[A] curves in the rabbit ear artery were analyzed using a theoretical model (Furchgott, 1972) describing the action of an enzyme inhibitor on the effects of a metabolically unstable agonist. This analysis provided an estimate of the pKi for FPL 67156 as an ecto-ATPase inhibitor of 5.2.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7533620

A 2MASS/AllWISE Search for Extremely Red L Dwarfs: The Discovery of Several Likely L Type Members of β Pic, AB Dor, Tuc-Hor, Argus, and the Hyades

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

Schneider, Adam C.; Shkolnik, Evgenya L.; Windsor, James

Young brown dwarfs share many properties with directly imaged giant extrasolar planets. They therefore provide unique laboratories for investigating the full range of temperature and mass encompassed by the growing collection of planets discovered outside our Solar System. Furthermore, if they can be tied to a particular group of coeval stars, they also provide vital anchor points for low-mass empirical isochrones. We have developed a novel procedure for identifying such objects based on their unique 2MASS and AllWISE colors. Using our search criteria, we have identified 50 new, late-type L dwarf candidates, 47 of which are spectroscopically confirmed as Lmore » dwarfs with follow-up near-infrared spectroscopy. We evaluate the potential membership of these objects in nearby, young moving groups using their proper motions, photometric distance estimates, and spectroscopic indicators of youth, and find seven likely L-type members belonging to the β Pictoris moving group, the AB Doradus moving group, the Tucana-Horologium association, or the Argus association, in addition to several lower probability members. Also found are two late-type (L5 and L6) potential members of the nearby Hyades cluster (WISEA J043642.75+190134.8 and WISEA J044105.56+213001.5).« less

Non-LTE hydrogen-line formation in moving prominences

NASA Technical Reports Server (NTRS)

Heinzel, P.; Rompolt, B.

1986-01-01

The behavior of hydrogen-line brightness variations, depending on the prominence-velocity changes were investigated. By solving the NON-Local thermodynamic equilibrium (LTE) problem for hydrogen researchers determine quantitatively the effect of Doppler brightening and/or Doppler dimming (DBE, DDE) in the lines of Lyman and Balmer series. It is demonstrated that in low-density prominence plasmas, DBE in H alpha and H beta lines can reach a factor of three for velocities around 160 km/sec, while the L alpha line exhibits typical DDE. L beta brightness variations follow from a combined DBE in the H alpha and DDE in L alpha and L beta itself, providing that all relevant multilevel interlocking processes are taken into account.

Structure of a Complete Mediator-RNA Polymerase II Pre-Initiation Complex.

PubMed

Robinson, Philip J; Trnka, Michael J; Bushnell, David A; Davis, Ralph E; Mattei, Pierre-Jean; Burlingame, Alma L; Kornberg, Roger D

2016-09-08

A complete, 52-protein, 2.5 million dalton, Mediator-RNA polymerase II pre-initiation complex (Med-PIC) was assembled and analyzed by cryo-electron microscopy and by chemical cross-linking and mass spectrometry. The resulting complete Med-PIC structure reveals two components of functional significance, absent from previous structures, a protein kinase complex and the Mediator-activator interaction region. It thereby shows how the kinase and its target, the C-terminal domain of the polymerase, control Med-PIC interaction and transcription. Copyright © 2016 Elsevier Inc. All rights reserved.

Beam-dynamics codes used at DARHT

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

Ekdahl, Jr., Carl August

Several beam simulation codes are used to help gain a better understanding of beam dynamics in the DARHT LIAs. The most notable of these fall into the following categories: for beam production – Tricomp Trak orbit tracking code, LSP Particle in cell (PIC) code, for beam transport and acceleration – XTR static envelope and centroid code, LAMDA time-resolved envelope and centroid code, LSP-Slice PIC code, for coasting-beam transport to target – LAMDA time-resolved envelope code, LSP-Slice PIC code. These codes are also being used to inform the design of Scorpius.

Inhibition of reactive oxygen species in hypothalamic paraventricular nucleus attenuates the renin–angiotensin system and proinflammatory cytokines in hypertension

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

Su, Qing; Qin, Da-Nian, E-mail: dnqin@stu.edu.cn; Wang, Fu-Xin

Aims: To explore whether reactive oxygen species (ROS) scavenger (tempol) in the hypothalamic paraventricular nucleus (PVN) attenuates renin–angiotensin system (RAS) and proinflammatory cytokines (PICs), and decreases the blood pressure and sympathetic activity in angiotensin II (ANG II)-induced hypertension. Methods and results: Male Sprague–Dawley rats were infused intravenously with ANG II (10 ng/kg per min) or normal saline (NS) for 4 weeks. These rats were treated with bilateral PVN infusion of oxygen free radical scavenger tempol (TEMP, 20 μg/h) or vehicle (artificial cerebrospinal fluid, aCSF) for 4 weeks. ANG II infusion resulted in increased mean arterial pressure (MAP) and renal sympatheticmore » nerve activity (RSNA). These ANG II-infused rats also had higher levels of gp91{sup phox} (a subunit of NAD(P)H oxidase), angiotensin-converting enzyme (ACE), and interleukin-1beta (IL-1β) in the PVN than the control animals. Treatment with PVN infusion of TEMP attenuated the overexpression of gp91{sup phox}, ACE and IL-1β within the PVN, and decreased sympathetic activity and MAP in ANG II-infused rats. Conclusion: These findings suggest that ANG II infusion induces elevated PICs and oxidative stress in the PVN, which contribute to the sympathoexcitation in hypertension. Inhibition of reactive oxygen species in hypothalamic paraventricular nucleus attenuates the renin–angiotensin system, proinflammatory cytokines and oxidative stress in ANG II-induced hypertension. - Highlights: • The effect of chronic inhibiting PVN superoxide on hypertension was investigated. • ANG II infusion induced increased proinflammatory cytokines and superoxide in PVN. • ANG II infusion resulted in oxidative stress, sympathoexcitation and hypertension. • Chronic inhibiting PVN superoxide attenuates RAS and cytokines in hypertension.« less

Inappropriate care in European ICUs: confronting views from nurses and junior and senior physicians.

PubMed

Piers, Ruth D; Azoulay, Elie; Ricou, Bara; DeKeyser Ganz, Freda; Max, Adeline; Michalsen, Andrej; Azevedo Maia, Paulo; Owczuk, Radoslaw; Rubulotta, Francesca; Meert, Anne-Pascale; Reyners, Anna K; Decruyenaere, Johan; Benoit, Dominique D

2014-08-01

ICU care providers often feel that the care given to a patient may be inconsistent with their professional knowledge or beliefs. This study aimed to assess differences in, and reasons for, perceived inappropriate care (PIC) across ICU care providers with varying levels of decision-making power. We present subsequent analysis from the Appropricus Study, a cross-sectional study conducted on May 11, 2010, which included 1,218 nurses and 180 junior and 227 senior physicians in 82 European adult ICUs. The study was designed to evaluate PIC. The current study focuses on differences across health-care providers regarding the reasons for PIC in real patient situations. By multivariate analysis, nurses were found to have higher PIC rates compared with senior and junior physicians. However, nurses and senior physicians were more distressed by perceived disproportionate care than were junior physicians (33%, 25%, and 9%, respectively; P = .026). A perceived mismatch between level of care and prognosis (mostly excessive care) was the most common cause of PIC. The main reasons for PIC were prognostic uncertainty among physicians, poor team and family communication, the fact that no one was taking the initiative to challenge the inappropriateness of care, and financial incentives to provide excessive care among nurses. Senior physicians, compared with nurses and junior physicians, more frequently reported pressure from the referring physician as a reason. Family-related factors were reported by similar proportions of participants in the three groups. ICU care providers agree that excessive care is a true issue in the ICU. However, they differ in the reasons for the PIC, reflecting the roles each caregiver has in the ICU. Nurses charge physicians with a lack of initiative and poor communication, whereas physicians more often ascribe prognostic uncertainty. Teaching ICU physicians to deal with prognostic uncertainty in more adequate ways and to promote ethical discussions in their teams may be pivotal to improving moral distress and the quality of patient care.

Chromium picolinate positively influences the glucose transporter system via affecting cholesterol homeostasis in adipocytes cultured under hyperglycemic diabetic conditions

PubMed Central

Pattar, Guruprasad R.; Tackett, Lixuan; Liu, Ping; Elmendorf, Jeffrey S.

2008-01-01

Since trivalent chromium (Cr3+) enhances glucose metabolism, interest in the use of Cr3+as a therapy for type 2 diabetes has grown in the mainstream medical community. Moreover, accumulating evidence suggests that Cr3+ may also benefit cardiovascular disease (CVD) and atypical depression. We have found that cholesterol, a lipid implicated in both CVD and neurodegenerative disorders, also influences cellular glucose uptake. A recent study in our laboratory shows that exposure of 3T3-L1 adipocytes to chromium picolinate (CrPic, 10 nM) induces a loss of plasma membrane cholesterol. Concomitantly, accumulation of intracellularly sequestered glucose transporter GLUT4 at the plasma membrane was dependent on the CrPic-induced cholesterol loss. Since CrPic supplementation has the greatest benefit on glucose metabolism in hyperglycemic insulin-resistant individuals, we asked here if the CrPic effect on cells was glucose-dependent. We found that GLUT4 redistribution in cells treated with CrPic occurs only in cells cultured under high glucose (25 mM) conditions that resemble the diabetic-state, and not in cells cultured under non-diabetic (5.5 mM glucose) conditions. Examination of the effect of CrPic on proteins involved in cholesterol homeostasis revealed that the activity of sterol regulatory element-binding protein (SREBP), a membrane-bound transcription factor ultimately responsible for controlling cellular cholesterol balance, was upregulated by CrPic. In addition, ABCA1, a major player in mediating cholesterol efflux was decreased, consistent with SREBP transcriptional repression of the ABCA1 gene. Although the exact mechanism of Cr3+-induced cholesterol loss remains to be determined, these cellular responses highlight a novel and significant effect of chromium on cholesterol homeostasis. Furthermore, these findings provide an important clue to our understanding of how chromium supplementation might benefit hypercholesterolemia-associated disorders. PMID:16870493

Chromium picolinate positively influences the glucose transporter system via affecting cholesterol homeostasis in adipocytes cultured under hyperglycemic diabetic conditions.

PubMed

Pattar, Guruprasad R; Tackett, Lixuan; Liu, Ping; Elmendorf, Jeffrey S

2006-11-07

Since trivalent chromium (Cr(3+)) enhances glucose metabolism, interest in the use of Cr(3+)as a therapy for type 2 diabetes has grown in the mainstream medical community. Moreover, accumulating evidence suggests that Cr(3+) may also benefit cardiovascular disease (CVD) and atypical depression. We have found that cholesterol, a lipid implicated in both CVD and neurodegenerative disorders, also influences cellular glucose uptake. A recent study in our laboratory shows that exposure of 3T3-L1 adipocytes to chromium picolinate (CrPic, 10 nM) induces a loss of plasma membrane cholesterol. Concomitantly, accumulation of intracellularly sequestered glucose transporter GLUT4 at the plasma membrane was dependent on the CrPic-induced cholesterol loss. Since CrPic supplementation has the greatest benefit on glucose metabolism in hyperglycemic insulin-resistant individuals, we asked here if the CrPic effect on cells was glucose-dependent. We found that GLUT4 redistribution in cells treated with CrPic occurs only in cells cultured under high glucose (25 mM) conditions that resemble the diabetic-state, and not in cells cultured under non-diabetic (5.5 mM glucose) conditions. Examination of the effect of CrPic on proteins involved in cholesterol homeostasis revealed that the activity of sterol regulatory element-binding protein (SREBP), a membrane-bound transcription factor ultimately responsible for controlling cellular cholesterol balance, was upregulated by CrPic. In addition, ABCA1, a major player in mediating cholesterol efflux was decreased, consistent with SREBP transcriptional repression of the ABCA1 gene. Although the exact mechanism of Cr(3+)-induced cholesterol loss remains to be determined, these cellular responses highlight a novel and significant effect of chromium on cholesterol homeostasis. Furthermore, these findings provide an important clue to our understanding of how chromium supplementation might benefit hypercholesterolemia-associated disorders.

1990 Environmental monitoring report, Tonopah Test Range, Tonopah, Nevada

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

Hwang, A.; Phelan, J.; Wolff, T.

1991-05-01

There is no routine radioactive emission from Sandia National Laboratories, Tonopah Test Range (SNL, TTR). However, based on the types of test activities such as air drops, gun firings, ground- launched rockets, air-launched rockets, and other explosive tests, possibilities exist that small amounts of depleted uranium (DU) (as part of weapon components) may be released to the air or to the ground because of unusual circumstances (failures) during testing. Four major monitoring programs were used in 1990 to assess radiological impact on the public. The EPA Air Surveillance Network (ASN) found that the only gamma ({gamma}) emitting radionuclide on themore » prefilters was beryllium-7 ({sup 7}Be), a naturally-occurring spallation product formed by the interaction of cosmic radiation with atmospheric oxygen and nitrogen. The weighted average results were consistent with the area background concentrations. The EPA Thermoluminescent Dosimetry (TLD) Network and Pressurized Ion Chamber (PIC) reported normal results. In the EPA Long-Term Hydrological Monitoring Program (LTHMP), analytical results for tritium ({sup 3}H) in well water were reported and were well below DOE-derived concentration guides (DCGs). In the Reynolds Electrical and Engineering Company (REECo) Drinking Water Sampling Program, analytical results for {sup 3}H, gross alpha ({alpha}), beta ({beta}), and {gamma} scan, strontium-90 ({sup 90}Sr) and plutonium-239 ({sup 239}Pu) were within the EPA's primary drinking water standards. 29 refs., 5 figs., 15 tabs.« less

Polymer impregnated bridge slabs : interim report.

DOT National Transportation Integrated Search

1979-01-01

The procedure used for producing precast slabs of polymer impregnated concrete (PIC) and described in this report was generally satisfactory from an operational standpoint. A strength loss of 14%, attributable to the drying step, was observed in PIC ...

Foundry fabricated photonic integrated circuit optical phase lock loop.

PubMed

Bałakier, Katarzyna; Fice, Martyn J; Ponnampalam, Lalitha; Graham, Chris S; Wonfor, Adrian; Seeds, Alwyn J; Renaud, Cyril C

2017-07-24

This paper describes the first foundry-based InP photonic integrated circuit (PIC) designed to work within a heterodyne optical phase locked loop (OPLL). The PIC and an external electronic circuit were used to phase-lock a single-line semiconductor laser diode to an incoming reference laser, with tuneable frequency offset from 4 GHz to 12 GHz. The PIC contains 33 active and passive components monolithically integrated on a single chip, fully demonstrating the capability of a generic foundry PIC fabrication model. The electronic part of the OPLL consists of commercially available RF components. This semi-packaged system stabilizes the phase and frequency of the integrated laser so that an absolute frequency, high-purity heterodyne signal can be generated when the OPLL is in operation, with phase noise lower than -100 dBc/Hz at 10 kHz offset from the carrier. This is the lowest phase noise level ever demonstrated by monolithically integrated OPLLs.

Expression of recombinant myostatin propeptide pPIC9K-Msp plasmid in Pichia pastoris.

PubMed

Du, W; Xia, J; Zhang, Y; Liu, M J; Li, H B; Yan, X M; Zhang, J S; Li, N; Zhou, Z Y; Xie, W Z

2015-12-28

Myostatin propeptide can inhibit the biological activity of myostatin protein and promote muscle growth. To express myostatin propeptide in vitro with a higher biological activity, we performed codon optimization on the sheep myostatin propeptide gene sequence, and mutated aspartic acid-76 to alanine based on the codon usage bias of Pichia pastoris and the enhanced biological activity of myostatin propeptide mutant. Modified myostatin propeptide gene was cloned into the pPIC9K plasmid to form the recombinant plasmid pPIC9K-Msp. Recombinant plasmid pPIC9K-Msp was transformed into Pichia pastoris GS115 by electrotransformation. Transformed cells were screened, and methanol was used to induce expression. SDS-PAGE and western blotting were used to verify the successful expression of myostatin propeptide with biological activity in Pichia pastoris, providing the basis for characterization of this protein.

Laser-plasma interactions with a Fourier-Bessel particle-in-cell method

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

Andriyash, Igor A., E-mail: igor.andriyash@gmail.com; LOA, ENSTA ParisTech, CNRS, Ecole polytechnique, Université Paris-Saclay, 828 bd des Maréchaux, 91762 Palaiseau cedex; Lehe, Remi

A new spectral particle-in-cell (PIC) method for plasma modeling is presented and discussed. In the proposed scheme, the Fourier-Bessel transform is used to translate the Maxwell equations to the quasi-cylindrical spectral domain. In this domain, the equations are solved analytically in time, and the spatial derivatives are approximated with high accuracy. In contrast to the finite-difference time domain (FDTD) methods, that are used commonly in PIC, the developed method does not produce numerical dispersion and does not involve grid staggering for the electric and magnetic fields. These features are especially valuable in modeling the wakefield acceleration of particles in plasmas.more » The proposed algorithm is implemented in the code PLARES-PIC, and the test simulations of laser plasma interactions are compared to the ones done with the quasi-cylindrical FDTD PIC code CALDER-CIRC.« less

Particle-In-Cell simulations of high pressure plasmas using graphics processing units

NASA Astrophysics Data System (ADS)

Gebhardt, Markus; Atteln, Frank; Brinkmann, Ralf Peter; Mussenbrock, Thomas; Mertmann, Philipp; Awakowicz, Peter

2009-10-01

Particle-In-Cell (PIC) simulations are widely used to understand the fundamental phenomena in low-temperature plasmas. Particularly plasmas at very low gas pressures are studied using PIC methods. The inherent drawback of these methods is that they are very time consuming -- certain stability conditions has to be satisfied. This holds even more for the PIC simulation of high pressure plasmas due to the very high collision rates. The simulations take up to very much time to run on standard computers and require the help of computer clusters or super computers. Recent advances in the field of graphics processing units (GPUs) provides every personal computer with a highly parallel multi processor architecture for very little money. This architecture is freely programmable and can be used to implement a wide class of problems. In this paper we present the concepts of a fully parallel PIC simulation of high pressure plasmas using the benefits of GPU programming.

Epicyclic helical channels for parametric resonance ionization cooling

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

Johson, Rolland Paul; Derbenev, Yaroslav

Proposed next-generation muon colliders will require major technical advances to achieve rapid muon beam cooling requirements. Parametric-resonance Ionization Cooling (PIC) is proposed as the final 6D cooling stage of a high-luminosity muon collider. In PIC, a half-integer parametric resonance causes strong focusing of a muon beam at appropriately placed energy absorbers while ionization cooling limits the beam’s angular spread. Combining muon ionization cooling with parametric resonant dynamics in this way should then allow much smaller final transverse muon beam sizes than conventional ionization cooling alone. One of the PIC challenges is compensation of beam aberrations over a sufficiently wide parametermore » range while maintaining the dynamical stability with correlated behavior of the horizontal and vertical betatron motion and dispersion. We explore use of a coupling resonance to reduce the dimensionality of the problem and to shift the dynamics away from non-linear resonances. PIC simulations are presented.« less

Pulsational mode-typing in line profile variables. I - Four Beta Cephei stars

NASA Technical Reports Server (NTRS)

Campos, A. J.; Smith, M. A.

1980-01-01

The detailed variations of line profiles in the Beta Cephei-type variable stars Gamma Pegasi, Beta Cephei, Delta Ceti and Sigma Scorpii are modeled throughout their pulsation cycles in order to classify the dominant pulsation mode as radial or nonradial. High-dispersion Reticon observations of the variables were obtained for the Si III line at 4567 A, and line profiles broadened by radial or nonradial pulsations, rotation and radial-tangential macroturbulence were calculated based on a model atmosphere. It is found that only a radial pulsation mode can reproduce the radial velocity amplitude, changes in line asymmetry and uniform line width observed in all four stars. Results are in agreement with the color-to-light arguments of Stamford and Watson (1978), and suggest that radial pulsation plays the dominant role in the observed variations in most Beta Cephei stars. Evidence for shocks or moving shells is also found in visual line data for Sigma Scorpii and an ultraviolet line of Beta Cephei, together with evidence of smooth, secular period changes in Beta Cephei and Delta Ceti.

Topics in Bayesian Hierarchical Modeling and its Monte Carlo Computations

NASA Astrophysics Data System (ADS)

Tak, Hyung Suk

The first chapter addresses a Beta-Binomial-Logit model that is a Beta-Binomial conjugate hierarchical model with covariate information incorporated via a logistic regression. Various researchers in the literature have unknowingly used improper posterior distributions or have given incorrect statements about posterior propriety because checking posterior propriety can be challenging due to the complicated functional form of a Beta-Binomial-Logit model. We derive data-dependent necessary and sufficient conditions for posterior propriety within a class of hyper-prior distributions that encompass those used in previous studies. Frequency coverage properties of several hyper-prior distributions are also investigated to see when and whether Bayesian interval estimates of random effects meet their nominal confidence levels. The second chapter deals with a time delay estimation problem in astrophysics. When the gravitational field of an intervening galaxy between a quasar and the Earth is strong enough to split light into two or more images, the time delay is defined as the difference between their travel times. The time delay can be used to constrain cosmological parameters and can be inferred from the time series of brightness data of each image. To estimate the time delay, we construct a Gaussian hierarchical model based on a state-space representation for irregularly observed time series generated by a latent continuous-time Ornstein-Uhlenbeck process. Our Bayesian approach jointly infers model parameters via a Gibbs sampler. We also introduce a profile likelihood of the time delay as an approximation of its marginal posterior distribution. The last chapter specifies a repelling-attracting Metropolis algorithm, a new Markov chain Monte Carlo method to explore multi-modal distributions in a simple and fast manner. This algorithm is essentially a Metropolis-Hastings algorithm with a proposal that consists of a downhill move in density that aims to make local modes repelling, followed by an uphill move in density that aims to make local modes attracting. The downhill move is achieved via a reciprocal Metropolis ratio so that the algorithm prefers downward movement. The uphill move does the opposite using the standard Metropolis ratio which prefers upward movement. This down-up movement in density increases the probability of a proposed move to a different mode.

Contribution of intrinsic properties and synaptic inputs to motoneuron discharge patterns: a simulation study

PubMed Central

ElBasiouny, Sherif M.; Rymer, W. Zev; Heckman, C. J.

2012-01-01

Motoneuron discharge patterns reflect the interaction of synaptic inputs with intrinsic conductances. Recent work has focused on the contribution of conductances mediating persistent inward currents (PICs), which amplify and prolong the effects of synaptic inputs on motoneuron discharge. Certain features of human motor unit discharge are thought to reflect a relatively stereotyped activation of PICs by excitatory synaptic inputs; these features include rate saturation and de-recruitment at a lower level of net excitation than that required for recruitment. However, PIC activation is also influenced by the pattern and spatial distribution of inhibitory inputs that are activated concurrently with excitatory inputs. To estimate the potential contributions of PIC activation and synaptic input patterns to motor unit discharge patterns, we examined the responses of a set of cable motoneuron models to different patterns of excitatory and inhibitory inputs. The models were first tuned to approximate the current- and voltage-clamp responses of low- and medium-threshold spinal motoneurons studied in decerebrate cats and then driven with different patterns of excitatory and inhibitory inputs. The responses of the models to excitatory inputs reproduced a number of features of human motor unit discharge. However, the pattern of rate modulation was strongly influenced by the temporal and spatial pattern of concurrent inhibitory inputs. Thus, even though PIC activation is likely to exert a strong influence on firing rate modulation, PIC activation in combination with different patterns of excitatory and inhibitory synaptic inputs can produce a wide variety of motor unit discharge patterns. PMID:22031773

Enhanced expression by the brain matrix of P-glycoprotein in brain capillary endothelial cells.

PubMed

Tatsuta, T; Naito, M; Mikami, K; Tsuruo, T

1994-10-01

P-glycoprotein (PGP), an active efflux pump of antitumor agents in multidrug-resistant tumor cells, exists in brain capillary endothelium and could be functionally involved in the blood-brain barrier. To study the regulatory mechanism of PGP expression in brain capillary endothelium, various mouse tissue matrices were tested for their abilities to enhance the expression of PGP in mouse brain capillary endothelial cells (MBEC), which express relatively small amounts of PGP. Of the four tissue matrices we examined, PGP expression in MBEC cultured on the brain matrix increased 2.0-fold. The PGP-inducing activity was similarly detected in bovine brain matrix, and the activity was enriched in the fraction of pl 9.0 by isoelectric focusing. The fraction, named PIC-fraction (PGP-inducing component), increased the PGP expression in MBEC 3.5-fold. By Northern blot analysis, a 3.3-fold enhancement of mdr gene expression was observed in MBEC cultured on the PIC-fraction. The PGP-inducing activity of the PIC-fraction was reduced by the treatment with trypsin but not with collagenase, suggesting that a proteinaceous factor distinct from type I collagen might be responsible for the PGP-inducing activity of PIC-fraction. Although the PIC-fraction increased the PGP expression in other mouse brain capillary endothelial cells, the PIC-fraction did not increase PGP expression in mouse aortic endothelial cells and KB carcinoma cell lines expressing various amounts of PGP. These observations suggest that PGP expression in brain capillary endothelium is specifically regulated by a tissue-specific factor in the brain matrix.

Effect of substituent groups (R= sbnd CH3, sbnd Br and sbnd CF3) on the structure, stability and redox property of [Cr(R-pic)2(H2O)2]NO3·H2O complexes

NASA Astrophysics Data System (ADS)

Chai, Jie; Liu, Yanfei; Liu, Bin; Yang, Binsheng

2017-12-01

Complexes [Cr(3-CH3-pic)2(H2O)2]NO3·H2O (1), [Cr(5-Br-pic)2(H2O)2]NO3·H2O (2) and [Cr(5-CF3-pic)2(H2O)2]NO3·H2O (3) were synthesized (pic = pyridine-2-carboxylic acid) and characterized by X-ray crystal diffraction. Crystal structure indicates that two bidentate ligands occupy equatorial position and two H2O occupy axial positions in trans-configuration. (i) Decomposition of complexes 1, 2 and 3 in different medium (phosphate buffered saline (PBS), apo-ovotransferrin (apootf) and EDTA) indicates that decomposition rate constants of these complexes follow the sequence of 1 < 2 < 3. (ii) The redox potential of Cr(III)/Cr(II) by cyclic voltammetry follows the sequence of 1 (-1.20 V) > 3 (-1.29 V) > 2 (-1.31 V). (iii) In addition, ·OH-generation of the new synthesized complexes was determined by Fenton-like reaction in comparison with Cr(pic)3, and it may be related to the reduction potential of the complexes. (iv) Moreover, Hammett substituent constants σp (inductive) and σm (resonance) (R = 3-CH3, 5-Br, 5-CF3) were introduced to evaluate the impact of substituent groups on the bond length and decomposition kinetics. The substituent group on the ligand has great effect on the properties of the complexes.

Hand washing compliance among retail food establishment workers in Minnesota.

PubMed

Allwood, Paul B; Jenkins, Timothy; Paulus, Colleen; Johnson, Lars; Hedberg, Craig W

2004-12-01

Inadequate hand washing by food workers is an important contributing factor to foodborne disease outbreaks in retail food establishments (RFEs). We conducted a survey of RFEs to investigate the effect of hand washing training, availability of hand washing facilities, and the ability of the person in charge (PIC) to describe hand washing according to the Minnesota Food Code (food code) on workers' ability to demonstrate food code-compliant hand washing. Only 52% of the PICs could describe the hand washing procedure outlined in the food code, and only 48% of workers could demonstrate code-compliant hand washing. The most common problems observed were failure to wash for 20 s and failure to use a fingernail brush. There was a strong positive association between the PIC being a certified food manager and being able to describe the food code hand washing procedure (odds ratio [OR], 5.5; 95% confidence interval [CI], 2.2 to 13.7), and there was an even stronger association between the PIC being able to describe hand washing and workers being able to demonstrate code-compliant hand washing (OR, 15; 95% CI, 6 to 37). Significant associations were detected among correct hand washing demonstration, physical infrastructure for hand washing, and the hand washing training methods used by the establishment. However, the principal determinant of successful hand washing demonstration was the PIC's ability to describe proper hand washing procedure. These results suggest that improving hand washing practices among food workers will require interventions that address PIC knowledge of hand washing requirement and procedure and the development and implementation of effective hand washing training methods.

Libre: Freeing Polar Data in an Information Commons

NASA Astrophysics Data System (ADS)

Duerr, R. E.; Parsons, M. A.

2010-12-01

As noted in the session description “The polar regions are at the forefront of modern environmental change, currently experiencing the largest and fastest changes in climate and environment”. Wise use of resources, astute management of our environment, improved decision support, and effective international cooperation on natural resource and geopolitical issues require a deeper understanding of, and an ability to predict change and its impact. Understanding and knowledge are built on data and information, yet polar information is scattered, scarce, and sporadic. Rapid change demands rapid data access. We envision a system where investigators quickly expose their data to the world and share them, without restriction, through open protocols on the Internet. A single giant, central archive is not practical for all polar data held around the world. Instead, we seek a collaborative, virtual space, where scientific data and information could be shared ethically and with minimal constraints. Inspired by the Antarctic Treaty of 1959 that established the Antarctic as a global commons to generate greater scientific understanding, the International Council of Science leads the Polar Information Commons (PIC). The PIC, engendered by the International Polar Year (IPY) and work on the IPY data policy, serves as an open, virtual repository for vital scientific data and information. An international network of scientific and data management organizations concerned with the scientific quality, integrity, and stewardship of data is developing the PIC. The PIC utilizes the Science Commons Protocol for Implementing Open Access Data, including establishment of community norms to encourage appropriate contributions to and use of PIC content. Data descriptions (metadata) are not necessarily registered in formal repositories or catalogues. They may simply be exposed to search engines or broadcast through syndication services such as RSS or Atom. The data are labeled or branded as part of the PIC and are, therefore, open for use without restriction. The PIC label also alerts data centers around the world to new polar data. These data centers then assess and acquire important data for formal archiving, curation, and access through national and global data systems. The intent is to enable rapid data access without qualification, while establishing a process for long-term preservation and stewardship of critical data. This paper will review the ethical and legal basis for sharing polar data and information, as well as the technologies being employed to make the PIC a reality.

Analysis of policy implications and challenges of the Cuban health assistance program related to human resources for health in the Pacific

PubMed Central

2012-01-01

Background Cuba has extended its medical cooperation to Pacific Island Countries (PICs) by supplying doctors to boost service delivery and offering scholarships for Pacific Islanders to study medicine in Cuba. Given the small populations of PICs, the Cuban engagement could prove particularly significant for health systems development in the region. This paper reviews the magnitude and form of Cuban medical cooperation in the Pacific and analyses its implications for health policy, human resource capacity and overall development assistance for health in the region. Methods We reviewed both published and grey literature on health workforce in the Pacific including health workforce plans and human resource policy documents. Further information was gathered through discussions with key stakeholders involved in health workforce development in the region. Results Cuba formalised its relationship with PICs in September 2008 following the first Cuba-Pacific Islands ministerial meeting. Some 33 Cuban health personnel work in Pacific Island Countries and 177 Pacific island students are studying medicine in Cuba in 2010 with the most extensive engagement in Kiribati, the Solomon Islands, Tuvalu and Vanuatu. The cost of the Cuban medical cooperation to PICs comes in the form of countries providing benefits and paying allowances to in-country Cuban health workers and return airfares for their students in Cuba. This has been seen by some PICs as a cheaper alternative to training doctors in other countries. Conclusions The Cuban engagement with PICs, while smaller than engagement with other countries, presents several opportunities and challenges for health system strengthening in the region. In particular, it allows PICs to increase their health workforce numbers at relatively low cost and extends delivery of health services to remote areas. A key challenge is that with the potential increase in the number of medical doctors, once the local students return from Cuba, some PICs may face substantial rises in salary expenditure which could significantly strain already stretched government budgets. Finally, the Cuban engagement in the Pacific has implications for the wider geo-political and health sector support environment as the relatively few major bilateral donors, notably Australia (through AusAID) and New Zealand (through NZAID), and multilaterals such as the World Bank will need to accommodate an additional player with whom existing links are limited. PMID:22558940

Comparison of HELIX TWT Simulation Using 2-D PIC (Magic), 2-D Modal (Gator), and 1-D Modal (Christine) Methods

DTIC Science & Technology

1998-05-01

Mission Research Corporation MRC/WDC-R-424 COMPARISON OF HELIX TWT SIMULATION USING 2-D PIC ( MAGIC ), 2-D MODAL (GATOR), AND 1-D MODAL (CHRISTINE...BRILLOUIN RUN 9 3.4 OUTLIER ELECTRON EFFECT IN GATOR 12 3.5 EMISSION CONDITION AND NONLAMINAR FLOW IN MAGIC 12 3.6 RADIAL SHEAR 13 SECTION 4. PPM B...Simulation using 2-D PIC ( MAGIC ), 2-D Modal (GATOR) and 1-D Modal (CHRISTINE) methods * D.N. Smithe(a), H. Freund(b), T. M. Antonsen Jr.,(b)’(c), E

Particle Acceleration in Pulsar Wind Nebulae: PIC Modelling

NASA Astrophysics Data System (ADS)

Sironi, Lorenzo; Cerutti, Benoît

We discuss the role of PIC simulations in unveiling the origin of the emitting particles in PWNe. After describing the basics of the PIC technique, we summarize its implications for the quiescent and the flaring emission of the Crab Nebula, as a prototype of PWNe. A consensus seems to be emerging that, in addition to the standard scenario of particle acceleration via the Fermi process at the termination shock of the pulsar wind, magnetic reconnection in the wind, at the termination shock and in the Nebula plays a major role in powering the multi-wavelength signatures of PWNe.

Synthesis and optoelectronic properties of a heterobimetallic Pt(II)-Ir(III) complex used as a single-component emitter in white PLEDs.

PubMed

Li, Xiaoshuang; Liu, Yu; Luo, Jian; Zhang, Zhiyong; Shi, Danyan; Chen, Qing; Wang, Yafei; He, Juan; Li, Jianming; Lei, Gangtie; Zhu, Weiguo

2012-03-14

To tune aggregation/excimer emission and obtain a single active emitter for white polymer light-emitting devices (PLEDs), a heterobimetallic Pt(II)-Ir(III) complex of FIr(pic)-C(6)DBC(6)-(pic)PtF was designed and synthesized, in which C(6)DBC(6) is a di(phenyloxyhexyloxy) bridging group, FIr(pic) is an iridium(III) bis[(4,6-difluorophenyl)pyridinato-N,C(2)'] (picolinate) chromophore and FPt(pic) is a platinum(II) [(4,6-difluorophenyl)pyridinato-N,C(2)'] (picolinate) chromophore. Its physical and opto-electronic properties were investigated. Interestingly, the excimer emission was efficiently controlled by this heterobimetallic Pt(II)-Ir(III) complex compared to the PL profile of the mononuclear FPt(pic) complex in the solid state. Near-white emissions were obtained in the single emissive layer (SEL) PLEDs using this heterobimetallic Pt(II)-Ir(III) complex as a single dopant and poly(vinylcarbazole) as a host matrix at dopant concentrations from 0.5 wt% to 2 wt%. This work indicates that incorporating a non-planar iridium(III) complex into the planar platinum(II) complex can control aggregation/excimer emissions and a single phosphorescent emitter can be obtained to exhibit white emission in SEL devices.

Fully integrated multi-optoelectronic synthesizer for THz pumping source in wireless communications with rich backup redundancy and wide tuning range.

PubMed

Xu, Junjie; Hou, Lianping; Deng, Qiufang; Han, Liangshun; Liang, Song; Marsh, John H; Zhu, Hongliang

2016-07-06

We report a monolithic photonic integrated circuit (PIC) for THz communication applications. The PIC generates up to 4 optical frequency lines which can be mixed in a separate device to generate THz radiation, and each of the optical lines can be modulated individually to encode data. Physically, the PIC comprises an array of wavelength tunable distributed feedback lasers each with its own electro-absorption modulator. The lasers are designed with a long cavity to operate with a narrow linewidth, typically <4 MHz. The light from the lasers is coupled via an multimode interference (MMI) coupler into a semiconductor optical amplifier (SOA). By appropriate selection and biasing of pairs of lasers, the optical beat signal can be tuned continuously over the range from 0.254 THz to 2.723 THz. The EAM of each channel enables signal leveling balanced between the lasers and realizing data encoding, currently at data rates up to 6.5 Gb/s. The PIC is fabricated using regrowth-free techniques, making it economic for volume applications, such for use in data centers. The PIC also has a degree of redundancy, making it suitable for applications, such as inter-satellite communications, where high reliability is mandatory.

Induction of cell self-organization on weakly positively charged surfaces prepared by the deposition of polyion complex nanoparticles of thermoresponsive, zwitterionic copolymers.

PubMed

Iwai, Ryosuke; Haruki, Ryota; Nemoto, Yasushi; Nakayama, Yasuhide

2017-07-01

We have developed inducible cell self-organization through weakly positively charged culture surfaces. In this study, a thermoresponsive and zwitterionic copolymer comprised of N,N-dimethylaminoethyl methacrylate (DMAEMA) and methacrylic acid (MA) (PDMAEMA-co-PMA; Mn: ∼9.7 × 10 4 g/mol; PDMAEMA/PMA ratio: 10) was designed for inducing cell self-organization. The copolymer formed single polymer-derived polyion complex (sPIC) nanoparticles following dissolution in an aqueous solution. The sPIC nanoparticles had a positive charge (ca. 25 mV). Self-organization occurred in adipose-derived vascular stromal cell monolayers cultivated on sPIC-deposited surfaces. There were dramatic morphological changes of these cells with the formation of capillary-like networks and single-cell aggregates with little cytotoxicity. This was a significant improvement compared with cells grown on previously developed surfaces deposited with PIC, a mixture of PDMAEMA and plasmid DNA. Thus, sPICs of PDMAEMA-co-PMA may allow for the accurate evaluation of a variety of cell behaviors with less cytotoxicity, and may facilitate additional potential medical applications such as cell-based therapy and drug discovery. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1009-1015, 2017. © 2016 Wiley Periodicals, Inc.

Statistics of Magnetic Reconnection X-Lines in Kinetic Turbulence

NASA Astrophysics Data System (ADS)

Haggerty, C. C.; Parashar, T.; Matthaeus, W. H.; Shay, M. A.; Wan, M.; Servidio, S.; Wu, P.

2016-12-01

In this work we examine the statistics of magnetic reconnection (x-lines) and their associated reconnection rates in intermittent current sheets generated in turbulent plasmas. Although such statistics have been studied previously for fluid simulations (e.g. [1]), they have not yet been generalized to fully kinetic particle-in-cell (PIC) simulations. A significant problem with PIC simulations, however, is electrostatic fluctuations generated due to numerical particle counting statistics. We find that analyzing gradients of the magnetic vector potential from the raw PIC field data identifies numerous artificial (or non-physical) x-points. Using small Orszag-Tang vortex PIC simulations, we analyze x-line identification and show that these artificial x-lines can be removed using sub-Debye length filtering of the data. We examine how turbulent properties such as the magnetic spectrum and scale dependent kurtosis are affected by particle noise and sub-Debye length filtering. We subsequently apply these analysis methods to a large scale kinetic PIC turbulent simulation. Consistent with previous fluid models, we find a range of normalized reconnection rates as large as ½ but with the bulk of the rates being approximately less than to 0.1. [1] Servidio, S., W. H. Matthaeus, M. A. Shay, P. A. Cassak, and P. Dmitruk (2009), Magnetic reconnection and two-dimensional magnetohydrodynamic turbulence, Phys. Rev. Lett., 102, 115003.

Chromium picolinate does not improve key features of metabolic syndrome in obese nondiabetic adults.

PubMed

Iqbal, Nayyar; Cardillo, Serena; Volger, Sheri; Bloedon, LeAnne T; Anderson, Richard A; Boston, Raymond; Szapary, Philippe O

2009-04-01

The use of chromium-containing dietary supplements is widespread among patients with type 2 diabetes. Chromium's effects in patients at high risk for developing diabetes, especially those with metabolic syndrome, is unknown. The objective of this study was to determine the effects of chromium picolinate (CrPic) on glucose metabolism in patients with metabolic syndrome. A double-blind, placebo-controlled, randomized trial was conducted at a U.S. academic medical center. Sixty three patients with National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP III)-defined metabolic syndrome were included. The primary end point was a change in the insulin sensitivity index derived from a frequently sampled intravenous glucose tolerance test. Prespecified secondary end points included changes in other measurements of glucose metabolism, oxidative stress, fasting serum lipids, and high sensitivity C-reactive protein. After 16 weeks of CrPic treatment, there was no significant change in insulin sensitivity index between groups (P = 0.14). However, CrPic increased acute insulin response to glucose (P 0.02). CrPic had no significant effect on other measures of glucose metabolism, body weight, serum lipids, or measures of inflammation and oxidative stress. CrPic at 1000 microg/day does not improve key features of the metabolic syndrome in obese nondiabetic patients.

Effects of pre- and postnatal exposure to chromium picolinate or picolinic acid on neurological development in CD-1 mice.

PubMed

Bailey, Melissa M; Boohaker, Jonathan G; Jernigan, Peter L; Townsend, Megan B; Sturdivant, John; Rasco, Jane F; Vincent, John B; Hood, Ronald D

2008-07-01

Chromium picolinate, Cr(pic)3, a popular dietary supplement marketed as an aid in fat loss and lean muscle gain, has also been suggested as a therapy for women with gestational diabetes. The current study investigated the effects of maternal exposure to Cr(pic)3 and picolinic acid during gestation and lactation on neurological development of the offspring. Mated female CD-1 mice were fed diets from implantation through weaning that were either untreated or that contained Cr(pic)3 (200 mg kg(-1) day(-1)) or picolinic acid (174 mg kg(-1) day(-1)). A comprehensive battery of postnatal tests was administered, including a modified Fox battery, straight-channel swim, open-field activity, and odor-discrimination tests. Pups exposed to picolinic acid tended to weigh less than either control or Cr(pic)3-exposed pups, although the differences were not significant. Offspring of picolinic acid-treated dams also appeared to display impaired learning ability, diminished olfactory orientation ability, and decreased forelimb grip strength, although the differences among the treatment groups were not significant. The results indicate that there were no significant effects on the offspring with regard to neurological development from supplementation of the dams with either Cr(pic)3 or picolinic acid.

Potential of chromium(III) picolinate for reproductive or developmental toxicity following exposure of male CD-1 mice prior to mating.

PubMed

McAdory, DeAna; Rhodes, Nicholas R; Briggins, Felicia; Bailey, Melissa M; Di Bona, Kristin R; Goodwin, Craig; Vincent, John B; Rasco, Jane F

2011-12-01

Chromium(III) picolinate, [Cr(pic)(3)], is a commonly used nutritional supplement in humans, which has also been approved for use in animals. Health concerns have arisen over the use of [Cr(pic)(3)]. At high [Cr(pic)(3)] doses, developmental toxicity tests in female mice have shown a higher litter incidence of split cervical arch in exposed fetuses, but this was not consistently reproducible. In the current study, male CD-1 mice were used to further assess the potential for reproductive or developmental toxicity. Four weeks prior to mating, the males were fed a diet providing 200 mg/kg/day [Cr(pic)(3)] for comparison with untreated controls. Females were not treated. Each male was mated with two females, which were sacrificed on gestation day 17, and their litters were examined for adverse effects. Mating and fertility indices were not significantly altered by treatment. Male exposure to [Cr(pic)(3)] also had no effect on prenatal mortality, fetal weight, or gross or skeletal morphology. These results suggest that paternal dietary exposure to chromium(III) picolinate has little potential for adverse reproductive effects, even at exposure levels considerably higher than expected human exposures from nutritional supplements (1 mg of Cr per day or less).

Gold nanoparticles hosted in a water-soluble silsesquioxane polymer applied as a catalytic material onto an electrochemical sensor for detection of nitrophenol isomers.

PubMed

Silva, Paulo Sérgio da; Gasparini, Bianca C; Magosso, Hérica A; Spinelli, Almir

2014-05-30

The water-soluble 3-n-propyl-4-picolinium silsesquioxane chloride (Si4Pic(+)Cl(-)) polymer was prepared, characterized and used as a stabilizing agent for the synthesis of gold nanoparticles (nAu). The ability of Si4Pic(+)Cl(-) to adsorb anionic metal complexes such as AuCl4(-) ions allowed well-dispersed nAu to be obtained with an average particle size of 4.5nm. The liquid suspension of nAu-Si4Pic(+)Cl(-) was deposited by the drop coating method onto a glassy carbon electrode (GCE) surface to build a sensor (nAu-Si4Pic(+)Cl(-)/GCE) which was used for the detection of o-nitrophenol (o-NP) and p-nitrophenol (p-NP). Under optimized experimental conditions the reduction peak current increased with increasing concentrations of both nitrophenol isomers in the range of 0.1-1.5μmolL(-1). The detection limits were 46nmolL(-1) and 55nmolL(-1) for o-NP and p-NP, respectively. These findings indicate that the nAu-Si4Pic(+)Cl(-) material is a very promising candidate to assemble electrochemical sensors for practical applications in the field of analytical chemistry. Copyright © 2014 Elsevier B.V. All rights reserved.

Adaptive and Personalized Plasma Insulin Concentration Estimation for Artificial Pancreas Systems.

PubMed

Hajizadeh, Iman; Rashid, Mudassir; Samadi, Sediqeh; Feng, Jianyuan; Sevil, Mert; Hobbs, Nicole; Lazaro, Caterina; Maloney, Zacharie; Brandt, Rachel; Yu, Xia; Turksoy, Kamuran; Littlejohn, Elizabeth; Cengiz, Eda; Cinar, Ali

2018-05-01

The artificial pancreas (AP) system, a technology that automatically administers exogenous insulin in people with type 1 diabetes mellitus (T1DM) to regulate their blood glucose concentrations, necessitates the estimation of the amount of active insulin already present in the body to avoid overdosing. An adaptive and personalized plasma insulin concentration (PIC) estimator is designed in this work to accurately quantify the insulin present in the bloodstream. The proposed PIC estimation approach incorporates Hovorka's glucose-insulin model with the unscented Kalman filtering algorithm. Methods for the personalized initialization of the time-varying model parameters to individual patients for improved estimator convergence are developed. Data from 20 three-days-long closed-loop clinical experiments conducted involving subjects with T1DM are used to evaluate the proposed PIC estimation approach. The proposed methods are applied to the clinical data containing significant disturbances, such as unannounced meals and exercise, and the results demonstrate the accurate real-time estimation of the PIC with the root mean square error of 7.15 and 9.25 mU/L for the optimization-based fitted parameters and partial least squares regression-based testing parameters, respectively. The accurate real-time estimation of PIC will benefit the AP systems by preventing overdelivery of insulin when significant insulin is present in the bloodstream.

Investigation of compositional segregation during unidirectional solidification of solid solution semiconducting alloys

NASA Technical Reports Server (NTRS)

Wang, J. C.

1982-01-01

Compositional segregation of solid solution semiconducting alloys in the radial direction during unidirectional solidification was investigated by calculating the effect of a curved solid liquid interface on solute concentration at the interface on the solid. The formulation is similar to that given by Coriell, Boisvert, Rehm, and Sekerka except that a more realistic cylindrical coordinate system which is moving with the interface is used. Analytical results were obtained for very small and very large values of beta with beta = VR/D, where V is the velocity of solidification, R the radius of the specimen, and D the diffusivity of solute in the liquid. For both very small and very large beta, the solute concentration at the interface in the solid C(si) approaches C(o) (original solute concentration) i.e., the deviation is minimal. The maximum deviation of C(si) from C(o) occurs for some intermediate value of beta.

Effect of beta-phenylethylamine on extracellular concentrations of dopamine in the nucleus accumbens and prefrontal cortex.

PubMed

Murata, Mikio; Katagiri, Nobuyuki; Ishida, Kota; Abe, Kenji; Ishikawa, Masago; Utsunomiya, Iku; Hoshi, Keiko; Miyamoto, Ken-ichi; Taguchi, Kyoji

2009-05-07

It is known that psychostimulants stimulate dopamine transmission in the nucleus accumbens. In the present study, we examined the effects of systemically administered beta-phenylethylamine (beta-PEA), a psychomotor-stimulating trace amine, on dopamine concentrations in the nucleus accumbens and prefrontal cortex in freely moving rats, using an in vivo microdialysis technique. Intraperitoneal administration of beta-PEA (12.5 and 25 mg/kg) significantly increased extracellular dopamine levels in the nucleus accumbens shell. The observed increase in the dopamine concentration in nucleus accumbens shell dialysate after intraperitoneal administration of 25 mg/kg beta-PEA was inhibited by pre-treatment with a dopamine uptake inhibitor, GBR12909 (10 mg/kg, i.p.). In contrast, beta-PEA (25 mg/kg, i.p.) did not affect dopamine release in the nucleus accumbens core. Although a high dose of beta-PEA (50 mg/kg) significantly increased dopamine levels in the nucleus accumbens core, the dopamine increasing effect of beta-PEA was more potent in the nucleus accumbens shell. Systemic administration of 12.5 and 25 mg/kg beta-PEA also increased extracellular dopamine levels in the prefrontal cortex of rats. However, systemic 25 mg/kg beta-PEA-induced increases in extracellular dopamine levels were not blocked by GBR12909 within the prefrontal cortex. These results suggest that beta-PEA has a greater effect in the shell than in the core and low-dose beta-PEA stimulates dopamine release in the nucleus accumbens shell through uptake by a dopamine transporter. Similarly, beta-PEA increased extracellular dopamine levels in the prefrontal cortex. Thus, beta-PEA may increase extracellular dopamine concentrations in the mesocorticolimbic pathway.

A novel chimeric peptide with antimicrobial activity.

PubMed

Alaybeyoglu, Begum; Akbulut, Berna Sariyar; Ozkirimli, Elif

2015-04-01

Beta-lactamase-mediated bacterial drug resistance exacerbates the prognosis of infectious diseases, which are sometimes treated with co-administration of beta-lactam type antibiotics and beta-lactamase inhibitors. Antimicrobial peptides are promising broad-spectrum alternatives to conventional antibiotics in this era of evolving bacterial resistance. Peptides based on the Ala46-Tyr51 beta-hairpin loop of beta-lactamase inhibitory protein (BLIP) have been previously shown to inhibit beta-lactamase. Here, our goal was to modify this peptide for improved beta-lactamase inhibition and cellular uptake. Motivated by the cell-penetrating pVEC sequence, which includes a hydrophobic stretch at its N-terminus, our approach involved the addition of LLIIL residues to the inhibitory peptide N-terminus to facilitate uptake. Activity measurements of the peptide based on the 45-53 loop of BLIP for enhanced inhibition verified that the peptide was a competitive beta-lactamase inhibitor with a K(i) value of 58 μM. Incubation of beta-lactam-resistant cells with peptide decreased the number of viable cells, while it had no effect on beta-lactamase-free cells, indicating that this peptide had antimicrobial activity via beta-lactamase inhibition. To elucidate the molecular mechanism by which this peptide moves across the membrane, steered molecular dynamics simulations were carried out. We propose that addition of hydrophobic residues to the N-terminus of the peptide affords a promising strategy in the design of novel antimicrobial peptides not only against beta-lactamase but also for other intracellular targets. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd.

Electrotransport and diffusivity of molybdenum, rhenium, tungsten, and zirconium in beta-thorium

NASA Technical Reports Server (NTRS)

Schmidt, F. A.; Beck, M. S.; Rehbein, D. K.; Conzemius, R. J.; Carlson, O. N.

1984-01-01

The electric mobilities, diffusivities, and effective valences were determined for molybdenum, rhenium, tungsten, and zirconium in beta-thorium. All four solutes migrated in the same direction as the electron flow. Rhenium and molybdenum were found to be very mobile, with tungsten somewhat slower. Zirconium was found to move at a rate near that of the self-diffusion of beta-thorium, viz., about 10 to the -11th sq m/s at 1500 C. The electromigration velocities showed a similar trend. A comparison was made between experimental data obtained by scanning laser mass spectrometry and theoretical transport equations for two purification experiments. Good agreement was obtained with both the concentration profile predicted by DeGroot and the purification ratio predicted by Verhoeven.

EXPERIMENTAL INVESTIGATION OF PIC FORMATION IN CFC-12 INCINERATION

EPA Science Inventory

The report gives results of experiments to determine the effect of flame zone temperature on gas-phase flame formation and destruction of products of incomplete combustion (PICS) during dichlorodi-fluoromethane (CFC-12) incineration. The effect of water injection into the flame ...

Acceptance Test Procedure for New Pumping Instrumentation and Control Skid Q

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

KOCH, M.R.

2000-03-27

This Acceptance Test Procedure (ATP) provides for the inspection and testing of the new Pumping Instrumentation and Control (PIC) skid designed as ''Q''. The ATP will be performed after the construction of the PIC skid in the fabrication shop.

On the numerical dispersion of electromagnetic particle-in-cell code: Finite grid instability

NASA Astrophysics Data System (ADS)

Meyers, M. D.; Huang, C.-K.; Zeng, Y.; Yi, S. A.; Albright, B. J.

2015-09-01

The Particle-In-Cell (PIC) method is widely used in relativistic particle beam and laser plasma modeling. However, the PIC method exhibits numerical instabilities that can render unphysical simulation results or even destroy the simulation. For electromagnetic relativistic beam and plasma modeling, the most relevant numerical instabilities are the finite grid instability and the numerical Cherenkov instability. We review the numerical dispersion relation of the Electromagnetic PIC model. We rigorously derive the faithful 3-D numerical dispersion relation of the PIC model, for a simple, direct current deposition scheme, which does not conserve electric charge exactly. We then specialize to the Yee FDTD scheme. In particular, we clarify the presence of alias modes in an eigenmode analysis of the PIC model, which combines both discrete and continuous variables. The manner in which the PIC model updates and samples the fields and distribution function, together with the temporal and spatial phase factors from solving Maxwell's equations on the Yee grid with the leapfrog scheme, is explicitly accounted for. Numerical solutions to the electrostatic-like modes in the 1-D dispersion relation for a cold drifting plasma are obtained for parameters of interest. In the succeeding analysis, we investigate how the finite grid instability arises from the interaction of the numerical modes admitted in the system and their aliases. The most significant interaction is due critically to the correct representation of the operators in the dispersion relation. We obtain a simple analytic expression for the peak growth rate due to this interaction, which is then verified by simulation. We demonstrate that our analysis is readily extendable to charge conserving models.

Evaluation of possible antioxidant and anticonvulsant effects of the ethyl acetate fraction from Platonia insignis Mart. (Bacuri) on epilepsy models.

PubMed

Júnior, Joaquim Soares da Costa; de Almeida, Antonia Amanda C; Tomé, Adriana da Rocha; Citó, Antonia Maria das Graças Lopes; Saffi, Jenifer; de Freitas, Rivelilson Mendes

2011-12-01

The aim of present study was to examine the effects of the ethyl acetate fraction (EAF) from Platonia insignis on lipid peroxidation level, nitrite formation, and superoxide dismutase and catalase activities in rat striatum prior to pilocarpine-induced seizures as well as to explore its anticonvulsant activity in adult rats prior to pentylenetetrazole (PTZ)- and picrotoxin (PIC)-induced seizures. Wistar rats were treated with vehicle, atropine (25mg/kg), EAF (0.1, 1, and 10mg/kg), pilocarpine (400mg/kg, P400 group), PTZ (60 mg/kg, PTZ group), PIC (8 mg/kg, PIC group), atropine+P400, EAF+P400, EAF+PTZ, or EAF+PIC. Significant decreases in number of crossings and rearings were observed in the P400 group. The EAF 10+P400 group also had significant increases in these parameters. In addition, in rats treated with P400, there were significant increases in lipid peroxidation and nitrite levels; however, there were no alterations in SOD and catalase activities. In the EAF 10+P400 group, lipid peroxidation and nitrite levels significantly decreased and SOD and catalase activities significantly increased after pilocarpine-induced seizures. Additionally, effects of the EAF were evaluated in PTZ and PIC models. EAF did not increase the latency to development of convulsions induced with PTZ and PIC at the doses tested. Our findings strongly support the hypothesis that EAF does not have anticonvulsant activity in the different models of epilepsy studied. Our results indicate that in the in vivo model of pilocarpine-induced seizures, EAF has antioxidant activity, but not anticonvulsant properties at the doses tested. Copyright © 2011. Published by Elsevier Inc.

Chromium picolinate enhances skeletal muscle cellular insulin signaling in vivo in obese, insulin-resistant JCR:LA-cp rats.

PubMed

Wang, Zhong Q; Zhang, Xian H; Russell, James C; Hulver, Matthew; Cefalu, William T

2006-02-01

Chromium is one of the few trace minerals for which a specific cellular mechanism of action has not been identified. Recent in vitro studies suggest that chromium supplementation may improve insulin sensitivity by enhancing insulin receptor signaling, but this has not been demonstrated in vivo. We investigated the effect of chromium supplementation on insulin receptor signaling in an insulin-resistant rat model, the JCR:LA-corpulent rat. Male JCR:LA-cp rats (4 mo of age) were randomly assigned to receive chromium picolinate (CrPic) (obese n=6, lean n=5) or vehicle (obese n=5, lean n=5) for 3 mo. The CrPic was provided in the water, and based on calculated water intake, rats randomized to CrPic received 80 microg/(kg.d). At the end of the study, skeletal muscle (vastus lateralis) biopsies were obtained at baseline and at 5, 15, and 30 min postinsulin stimulation to assess insulin signaling. Obese rats treated with CrPic had significantly improved glucose disposal rates and demonstrated a significant increase in insulin-stimulated phosphorylation of insulin receptor substrate (IRS)-1 and phosphatidylinositol (PI)-3 kinase activity in skeletal muscle compared with obese controls. The increase in cellular signaling was not associated with increased protein levels of the IRS proteins, PI-3 kinase or Akt. However, protein tyrosine phosphatase 1B (PTP1B) levels were significantly lower in obese rats administered CrPic than obese controls. When corrected for protein content, PTP1B activity was also significantly lower in obese rats administered CrPic than obese controls. Our data suggest that chromium supplementation of obese, insulin-resistant rats may improve insulin action by enhancing intracellular signaling.

Encapsulation of rat bone marrow stromal cells using a poly-ion complex gel of chitosan and succinylated poly(Pro-Hyp-Gly).

PubMed

Kusumastuti, Yuni; Shibasaki, Yoshiaki; Hirohara, Shiho; Kobayashi, Mime; Terada, Kayo; Ando, Tsuyoshi; Tanihara, Masao

2017-03-01

Encapsulation of stem cells into a three-dimensional (3D) scaffold is necessary to achieve tissue regeneration. Prefabricated 3D scaffolds, such as fibres or porous sponges, have limitations regarding homogeneous cell distribution. Hydrogels that can encapsulate cells such as animal-derived collagen gels need adjustment of the pH and/or temperature upon cell mixing. In this report, we fabricated a poly-ion complex (PIC) hydrogel of chitosan and succinylated poly(Pro-Hyp-Gly) and assessed its effect on cell viability after encapsulation of rat bone marrow stromal cells. PIC hydrogels were obtained successfully with a concentration of each precursor as low as 3.0-3.8 mg/ml. The maximum gelation and swelling ratios were achieved with an equal molar ratio (1:1) of anionic and cationic groups. Using chitosan acetate as a cationic precursor produced a PIC hydrogel with both a significantly greater gelation ratio and a better swelling ratio than chitosan chloride. Ammonium succinylated poly(Pro-Hyp-Gly) as an anionic precursor gave similar gelation and swelling ratios to those of sodium succinylated poly(Pro-Hyp-Gly). Cell encapsulation was also achieved successfully by mixing rat bone marrow stromal cells with the PIC hydrogel simultaneously during its formation. The PIC hydrogel was maintained in the culture medium for 7 days at 37°C and the encapsulated cells survived and proliferated in it. Although it is necessary to improve its functionality, this PIC hydrogel has the potential to act as a 3D scaffold for cell encapsulation and tissue regeneration. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Core Mediator structure at 3.4 Å extends model of transcription initiation complex.

PubMed

Nozawa, Kayo; Schneider, Thomas R; Cramer, Patrick

2017-05-11

Mediator is a multiprotein co-activator that binds the transcription pre-initiation complex (PIC) and regulates RNA polymerase (Pol) II. The Mediator head and middle modules form the essential core Mediator (cMed), whereas the tail and kinase modules play regulatory roles. The architecture of Mediator and its position on the PIC are known, but atomic details are limited to Mediator subcomplexes. Here we report the crystal structure of the 15-subunit cMed from Schizosaccharomyces pombe at 3.4 Å resolution. The structure shows an unaltered head module, and reveals the intricate middle module, which we show is globally required for transcription. Sites of known Mediator mutations cluster at the interface between the head and middle modules, and in terminal regions of the head subunits Med6 (ref. 16) and Med17 (ref. 17) that tether the middle module. The structure led to a model for Saccharomyces cerevisiae cMed that could be combined with the 3.6 Å cryo-electron microscopy structure of the core PIC (cPIC). The resulting atomic model of the cPIC-cMed complex informs on interactions of the submodules forming the middle module, called beam, knob, plank, connector, and hook. The hook is flexibly linked to Mediator by a conserved hinge and contacts the transcription initiation factor IIH (TFIIH) kinase that phosphorylates the carboxy (C)-terminal domain (CTD) of Pol II and was recently positioned on the PIC. The hook also contains residues that crosslink to the CTD and reside in a previously described cradle. These results provide a framework for understanding Mediator function, including its role in stimulating CTD phosphorylation by TFIIH.

On the numerical dispersion of electromagnetic particle-in-cell code: Finite grid instability

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

Meyers, M.D., E-mail: mdmeyers@physics.ucla.edu; Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, CA 90095; Huang, C.-K., E-mail: huangck@lanl.gov

The Particle-In-Cell (PIC) method is widely used in relativistic particle beam and laser plasma modeling. However, the PIC method exhibits numerical instabilities that can render unphysical simulation results or even destroy the simulation. For electromagnetic relativistic beam and plasma modeling, the most relevant numerical instabilities are the finite grid instability and the numerical Cherenkov instability. We review the numerical dispersion relation of the Electromagnetic PIC model. We rigorously derive the faithful 3-D numerical dispersion relation of the PIC model, for a simple, direct current deposition scheme, which does not conserve electric charge exactly. We then specialize to the Yee FDTDmore » scheme. In particular, we clarify the presence of alias modes in an eigenmode analysis of the PIC model, which combines both discrete and continuous variables. The manner in which the PIC model updates and samples the fields and distribution function, together with the temporal and spatial phase factors from solving Maxwell's equations on the Yee grid with the leapfrog scheme, is explicitly accounted for. Numerical solutions to the electrostatic-like modes in the 1-D dispersion relation for a cold drifting plasma are obtained for parameters of interest. In the succeeding analysis, we investigate how the finite grid instability arises from the interaction of the numerical modes admitted in the system and their aliases. The most significant interaction is due critically to the correct representation of the operators in the dispersion relation. We obtain a simple analytic expression for the peak growth rate due to this interaction, which is then verified by simulation. We demonstrate that our analysis is readily extendable to charge conserving models.« less

EXPERIMENTAL INVESTIGATION OF PIC FORMATION DURING THE INCINERATION OF RECOVERED CFC-11

EPA Science Inventory

The report gives results of an investigation of the formation of products of incomplete combustion (PICS) during "recovered" trichlorofluoromethane (CFC-11) incineration. Tests involved burning the recovered CFC-11 in a propane gas flame. combustion gas samples were taken and an...

Enhancement of plasmon-induced charge separation efficiency by coupling silver nanocubes with a thin gold film

NASA Astrophysics Data System (ADS)

Akiyoshi, Kazutaka; Saito, Koichiro; Tatsuma, Tetsu

2016-10-01

Plasmon-induced charge separation (PICS), in which an energetic electron is injected from a plasmonic nanoparticle (NP) to a semiconductor on contact, is often inhibited by a protecting agent adsorbed on the NP. We addressed this issue for an Ag nanocube-TiO2 system by coating it with a thin Au layer or by inserting the Au layer between the nanocubes (NCs) and TiO2. Both of the electrodes exhibit much higher photocurrents due to PICS than the electrodes without the Au film or the Ag NCs. These photocurrent enhancements can be explained in terms of PICS with accelerated electron transfer, in which electron injection from the Ag NCs or Ag@Au core-shell NCs to TiO2 is promoted by the Au film, or PICS enhanced by a nanoantenna effect, in which the electron injection from the Au film to TiO2 is enhanced by optical near field generated by the Ag NC.

Identification and characterization of a non-satellite cell muscle resident progenitor during postnatal development.

PubMed

Mitchell, Kathryn J; Pannérec, Alice; Cadot, Bruno; Parlakian, Ara; Besson, Vanessa; Gomes, Edgar R; Marazzi, Giovanna; Sassoon, David A

2010-03-01

Satellite cells are resident myogenic progenitors in postnatal skeletal muscle involved in muscle postnatal growth and adult regenerative capacity. Here, we identify and describe a population of muscle-resident stem cells, which are located in the interstitium, that express the cell stress mediator PW1 but do not express other markers of muscle stem cells such as Pax7. PW1(+)/Pax7(-) interstitial cells (PICs) are myogenic in vitro and efficiently contribute to skeletal muscle regeneration in vivo as well as generating satellite cells and PICs. Whereas Pax7 mutant satellite cells show robust myogenic potential, Pax7 mutant PICs are unable to participate in myogenesis and accumulate during postnatal growth. Furthermore, we found that PICs are not derived from a satellite cell lineage. Taken together, our findings uncover a new and anatomically identifiable population of muscle progenitors and define a key role for Pax7 in a non-satellite cell population during postnatal muscle growth.

A curvilinear, fully implicit, conservative electromagnetic PIC algorithm in multiple dimensions

DOE PAGES

Chacon, L.; Chen, G.

2016-04-19

Here, we extend a recently proposed fully implicit PIC algorithm for the Vlasov–Darwin model in multiple dimensions (Chen and Chacón (2015) [1]) to curvilinear geometry. As in the Cartesian case, the approach is based on a potential formulation (Φ, A), and overcomes many difficulties of traditional semi-implicit Darwin PIC algorithms. Conservation theorems for local charge and global energy are derived in curvilinear representation, and then enforced discretely by a careful choice of the discretization of field and particle equations. Additionally, the algorithm conserves canonical-momentum in any ignorable direction, and preserves the Coulomb gauge ∇ • A = 0 exactly. Anmore » asymptotically well-posed fluid preconditioner allows efficient use of large cell sizes, which are determined by accuracy considerations, not stability, and can be orders of magnitude larger than required in a standard explicit electromagnetic PIC simulation. We demonstrate the accuracy and efficiency properties of the algorithm with numerical experiments in mapped meshes in 1D-3V and 2D-3V.« less

A curvilinear, fully implicit, conservative electromagnetic PIC algorithm in multiple dimensions

NASA Astrophysics Data System (ADS)

Chacón, L.; Chen, G.

2016-07-01

We extend a recently proposed fully implicit PIC algorithm for the Vlasov-Darwin model in multiple dimensions (Chen and Chacón (2015) [1]) to curvilinear geometry. As in the Cartesian case, the approach is based on a potential formulation (ϕ, A), and overcomes many difficulties of traditional semi-implicit Darwin PIC algorithms. Conservation theorems for local charge and global energy are derived in curvilinear representation, and then enforced discretely by a careful choice of the discretization of field and particle equations. Additionally, the algorithm conserves canonical-momentum in any ignorable direction, and preserves the Coulomb gauge ∇ ṡ A = 0 exactly. An asymptotically well-posed fluid preconditioner allows efficient use of large cell sizes, which are determined by accuracy considerations, not stability, and can be orders of magnitude larger than required in a standard explicit electromagnetic PIC simulation. We demonstrate the accuracy and efficiency properties of the algorithm with numerical experiments in mapped meshes in 1D-3V and 2D-3V.

Design and implementation of the standards-based personal intelligent self-management system (PICS).

PubMed

von Bargen, Tobias; Gietzelt, Matthias; Britten, Matthias; Song, Bianying; Wolf, Klaus-Hendrik; Kohlmann, Martin; Marschollek, Michael; Haux, Reinhold

2013-01-01

Against the background of demographic change and a diminishing care workforce there is a growing need for personalized decision support. The aim of this paper is to describe the design and implementation of the standards-based personal intelligent care systems (PICS). PICS makes consistent use of internationally accepted standards such as the Health Level 7 (HL7) Arden syntax for the representation of the decision logic, HL7 Clinical Document Architecture for information representation and is based on a open-source service-oriented architecture framework and a business process management system. Its functionality is exemplified for the application scenario of a patient suffering from congestive heart failure. Several vital signs sensors provide data for the decision support system, and a number of flexible communication channels are available for interaction with patient or caregiver. PICS is a standards-based, open and flexible system enabling personalized decision support. Further development will include the implementation of components on small computers and sensor nodes.

Evidence that Mediator is essential for Pol II transcription, but is not a required component of the preinitiation complex in vivo.

PubMed

Petrenko, Natalia; Jin, Yi; Wong, Koon Ho; Struhl, Kevin

2017-07-12

The Mediator complex has been described as a general transcription factor, but it is unclear if it is essential for Pol II transcription and/or is a required component of the preinitiation complex (PIC) in vivo. Here, we show that depletion of individual subunits, even those essential for cell growth, causes a general but only modest decrease in transcription. In contrast, simultaneous depletion of all Mediator modules causes a drastic decrease in transcription. Depletion of head or middle subunits, but not tail subunits, causes a downstream shift in the Pol II occupancy profile, suggesting that Mediator at the core promoter inhibits promoter escape. Interestingly, a functional PIC and Pol II transcription can occur when Mediator is not detected at core promoters. These results provide strong evidence that Mediator is essential for Pol II transcription and stimulates PIC formation, but it is not a required component of the PIC in vivo.

Exploiting metamaterials, plasmonics and nanoantennas concepts in silicon photonics

NASA Astrophysics Data System (ADS)

Rodríguez-Fortuño, Francisco J.; Espinosa-Soria, Alba; Martínez, Alejandro

2016-12-01

The interaction of light with subwavelength metallic nano-structures is at the heart of different current scientific hot topics, namely plasmonics, metamaterials and nanoantennas. Research in these disciplines during the last decade has given rise to new, powerful concepts providing an unprecedented degree of control over light manipulation at the nanoscale. However, only recently have these concepts been used to increase the capabilities of light processing in current photonic integrated circuits (PICs), which traditionally rely only on dielectric materials with element sizes larger than the light wavelength. Amongst the different PIC platforms, silicon photonics is expected to become mainstream, since manufacturing using well-established CMOS processes enables the mass production of low-cost PICs. In this review we discuss the benefits of introducing recent concepts arisen from the fields of metamaterials, plasmonics and nanoantennas into a silicon photonics integrated platform. We review existing works in this direction and discuss how this hybrid approach can lead to the improvement of current PICs enabling novel and disruptive applications in photonics.

Effects of increased vertebral number on carcass weight in PIC pigs.

PubMed

Huang, Jieping; Zhang, Mingming; Ye, Runqing; Ma, Yun; Lei, Chuzhao

2017-12-01

Variation of the vertebral number is associated with carcass traits in pigs. However, results from different populations do not match well with others, especially for carcass weight. Therefore, effects of increased vertebral number on carcass weight were investigated by analyzing the relationship between two loci multi-vertebra causal loci (NR6A1 g.748 C > T and VRTN g.20311_20312ins291) and carcass weight in PIC pigs. Results from the association study between vertebral number and carcass weight showed that increased thoracic number had negative effects on carcass weight, but the results were not statistically significant. Further, VRTN Ins/Ins genotype increased more than one thoracic than that of Wt/Wt genotype on average in this PIC population. Meanwhile, there was a significant negative effect of VRTN Ins on carcass weight (P < 0.05). Thus, our results suggested negative effect of increased thoracic number on carcass weight in PIC pigs. © 2017 Japanese Society of Animal Science.

A curvilinear, fully implicit, conservative electromagnetic PIC algorithm in multiple dimensions

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

Chacon, L.; Chen, G.

Here, we extend a recently proposed fully implicit PIC algorithm for the Vlasov–Darwin model in multiple dimensions (Chen and Chacón (2015) [1]) to curvilinear geometry. As in the Cartesian case, the approach is based on a potential formulation (Φ, A), and overcomes many difficulties of traditional semi-implicit Darwin PIC algorithms. Conservation theorems for local charge and global energy are derived in curvilinear representation, and then enforced discretely by a careful choice of the discretization of field and particle equations. Additionally, the algorithm conserves canonical-momentum in any ignorable direction, and preserves the Coulomb gauge ∇ • A = 0 exactly. Anmore » asymptotically well-posed fluid preconditioner allows efficient use of large cell sizes, which are determined by accuracy considerations, not stability, and can be orders of magnitude larger than required in a standard explicit electromagnetic PIC simulation. We demonstrate the accuracy and efficiency properties of the algorithm with numerical experiments in mapped meshes in 1D-3V and 2D-3V.« less

The effect of a guide field on local energy conversion during asymmetric magnetic reconnection: Particle-in-cell simulations

NASA Astrophysics Data System (ADS)

Cassak, P.; Genestreti, K.; Burch, J. L.; Shay, M.; Swisdak, M.; Drake, J. F.; Price, L.; Eriksson, S.; Anderson, B. J.; Merkin, V. G.; Komar, C. M.; Phan, T.; Ergun, R.

2017-12-01

We use theoretical and computational techniques to study how the out-of-plane (guide) magnetic field strength modifies the location where the energy conversion rate between the electric field and the plasma is appreciable during asymmetric magnetic reconnection, motivated by observations by Genestreti et al. (J. Geophys. Res, submitted). For weak guide fields, the energy conversion rate is maximum midway between the X-line and electron stagnation point. As the guide field increases, it moves towards the electron stagnation point. We motivate how to extend the theory of the location of the stagnation points to include the effect of a guide field. The predictions are compared to two-dimensional (2D) particle-in-cell (PIC) simulations with vastly different guide fields. The simulations have upstream parameters corresponding to three reconnection events observed with MMS. The predictions agree reasonably well with the simulation results, having captured trends with the guide field. The theory correctly predicts that the energy conversion is closer to the X-line in the absolute sense as the guide field increases. The results are then compared to MMS observations, Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) observations of each event, and global resistive magnetohydrodynamics simulations of the 2015 Oct 16 event. The PIC simulation results agree well with the global observations and simulations, but differ in the strong electric fields and energy conversion rates found in the MMS observations. The results suggest that the strong electric fields observed by MMS do not represent a steady global rate.

Muscle length-dependent contribution of motoneuron Cav1.3 channels to force production in model slow motor unit.

PubMed

Kim, Hojeong

2017-07-01

Persistent inward current (PIC)-generating Ca v 1.3 channels in spinal motoneuron dendrites are thought to be actively recruited during normal behaviors. However, whether and how the activation of PIC channels influences force output of motor unit remains elusive. Here, building a physiologically realistic model of slow motor unit I demonstrated that force production induced by the PIC activation is much smaller for short than lengthened muscles during the regular firing of the motoneuron that transitions from the quiescent state by either a brief current pulse at the soma or a brief synaptic excitation at the dendrites. By contrast, the PIC-induced force potentiation was maximal for short muscles when the motoneuron switched from a stable low-frequency firing state to a stable high-frequency firing state by the current pulse at the soma. Under the synaptic excitation at the dendrites, however, the force could not be potentiated by the transitioning of the motoneuron from a low- to a high-frequency firing state due to the simultaneous onset of PIC at the dendrites and firing at the soma. The strong dependency of the input-output relationship of the motor unit on the neuromodulation and Ia afferent inputs for the PIC channels was further shown under static variations in muscle length. Taken together, these findings suggest that the PIC activation in the motoneuron dendrites may differentially affect the force production of the motor unit, depending not only on the firing state history of the motoneuron and the variation in muscle length but also on the mode of motor activity. NEW & NOTEWORTHY Ca v 1.3 channels in motoneuron dendrites are actively involved during normal motor activities. To investigate the effects of the activation of motoneuron Ca v 1.3 channels on force production, a model motor unit was built based on best-available data. The simulation results suggest that force potentiation induced by Ca v 1.3 channel activation is strongly modulated not only by firing history of the motoneuron but also by length variation of the muscle as well as neuromodulation inputs from the brainstem. Copyright © 2017 the American Physiological Society.

Peri-Implantitis Associated with Type of Cement: A Retrospective Analysis of Different Types of Cement and Their Clinical Correlation to the Peri-Implant Tissue.

PubMed

Korsch, Michael; Walther, Winfried

2015-10-01

The cementation of fixed implant-supported dental restorations involves the risk of leaving excess cement in the mouth which can promote biofilm formation in the peri-implant sulcus. As a result, an inflammation may develop. The aim of the present study was to investigate the clinical effect of two different luting cements on the peri-implant tissue. Within the scope of a retrospective clinical follow-up study, the prosthetic structures of 22 patients with 45 implants were revised. In all cases, a methacrylate cement (Premier Implant Cement [PIC], Premier® Dental Products Company, Plymouth Meeting, PA, USA) had been used for cementation. In 16 additional patients with 28 implants, the suprastructures were retained with a zinc oxide-eugenol cement (Temp Bond [TB], Kerr Sybron Dental Specialities, Glendora, CA, USA). These patients were evaluated in the course of routine treatment. In both populations, the retention time of the suprastructures was similar (TB 3.77 years, PIC 4.07 years). In the PIC cases, 62% of all implants had excess cement. In the TB cases, excess cement was not detectable on any of the implants. Bleeding on probing was significantly more frequent on implants cemented with PIC (100% with and 94% without excess cement) than on implants cemented with TB (46%). Pocket suppuration was observed on 89% of the PIC-cemented implants with excess cement (PIC without excess cement 24%), whereas implants with TB were not affected by it at all. The peri-implant bone loss was significantly greater in the PIC patients (with excess cement 1.37 mm, without excess cement 0.41 mm) than it was in the TB patients (0.07 mm). The frequency of undetected excess cement depends essentially on the type of cement used. Cements that tend to leave more undetected excess have a higher prevalence for peri-implant inflammation and cause a more severe peri-implant bone loss. © 2014 Wiley Periodicals, Inc.

The effects of dietary supplementation with chromium picolinate throughout gestation on productive performance, Cr concentration, serum parameters, and colostrum composition in sows.

PubMed

Wang, Liansheng; Shi, Zhan; Jia, Zhiqiang; Su, Binchao; Shi, Baoming; Shan, Anshan

2013-07-01

The objective of this study was to determine the effects of supplemental chromium as chromium picolinate (CrPic) on productive performance, chromium (Cr) concentration, serum parameters, and colostrum composition in sows. Thirty Yorkshire sows were bred with semen from a pool of Landrace boars. The sows were equally grouped and treated with either a diet containing 0 (control) or 400 ppb dietary Cr supplementation throughout gestation. The sows received the same basal diet based on corn-DDGS meal. Supplemental CrPic increased (P < 0.05) the sow body mass gain from the insemination to the day 110 of gestation in sows. No differences (P > 0.50) were observed in the gestation interval, sow mass, and backfat at insemination, after farrowing, at weaning and lactation loss. The number of piglets born alive, piglets per litter at weaning, and litter weaned mass were increased (P < 0.05) for those supplemented with CrPic compared with the control. However, the total number of piglets born, total born litter mass, average piglet birth body mass, born alive litter mass, and average born alive piglet mass did not differ among the treatments (P > 0.05). The placental masses of sows were similar among treatments (P > 0.05). Dietary supplementation with CrPic throughout gestation in sows showed increased (P < 0.01) concentration of Cr in the colostrum or serum at days 70 and 110. Compared with the control group, dietary supplementation with CrPic throughout gestation in sows decreased (P < 0.05) the serum insulin concentration, the glucose or serum urea nitrogen concentration at days 70 and 110. However, no differences (P > 0.05) were observed in total protein concentration among treatments. No differences (P > 0.05) were observed in total solids, protein, fat or lactose among sows fed the diets supplemented with CrPic compared with the control. This exciting finding provides evidence for an increase in mass gain and live-born piglets in sows supplemented with CrPic throughout gestation.

Enhanced quasi-static particle-in-cell simulation of electron cloud instabilities in circular accelerators

NASA Astrophysics Data System (ADS)

Feng, Bing

Electron cloud instabilities have been observed in many circular accelerators around the world and raised concerns of future accelerators and possible upgrades. In this thesis, the electron cloud instabilities are studied with the quasi-static particle-in-cell (PIC) code QuickPIC. Modeling in three-dimensions the long timescale propagation of beam in electron clouds in circular accelerators requires faster and more efficient simulation codes. Thousands of processors are easily available for parallel computations. However, it is not straightforward to increase the effective speed of the simulation by running the same problem size on an increasingly number of processors because there is a limit to domain size in the decomposition of the two-dimensional part of the code. A pipelining algorithm applied on the fully parallelized particle-in-cell code QuickPIC is implemented to overcome this limit. The pipelining algorithm uses multiple groups of processors and optimizes the job allocation on the processors in parallel computing. With this novel algorithm, it is possible to use on the order of 102 processors, and to expand the scale and the speed of the simulation with QuickPIC by a similar factor. In addition to the efficiency improvement with the pipelining algorithm, the fidelity of QuickPIC is enhanced by adding two physics models, the beam space charge effect and the dispersion effect. Simulation of two specific circular machines is performed with the enhanced QuickPIC. First, the proposed upgrade to the Fermilab Main Injector is studied with an eye upon guiding the design of the upgrade and code validation. Moderate emittance growth is observed for the upgrade of increasing the bunch population by 5 times. But the simulation also shows that increasing the beam energy from 8GeV to 20GeV or above can effectively limit the emittance growth. Then the enhanced QuickPIC is used to simulate the electron cloud effect on electron beam in the Cornell Energy Recovery Linac (ERL) due to extremely small emittance and high peak currents anticipated in the machine. A tune shift is discovered from the simulation; however, emittance growth of the electron beam in electron cloud is not observed for ERL parameters.

Numerical Studies of Optimization and Aberration Correction Methods for the Preliminary Demonstration of the Parametric Ionization Cooling (PIC) Principle in the Twin Helix Muon Cooling Channel

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

Maloney, J. A.; Morozov, V. S.; Derbenev, Ya. S.

Muon colliders have been proposed for the next generation of particle accelerators that study high-energy physics at the energy and intensity frontiers. In this paper we study a possible implementation of muon ionization cooling, Parametric-resonance Ionization Cooling (PIC), in the twin helix channel. The resonant cooling method of PIC offers the potential to reduce emittance beyond that achievable with ionization cooling with ordinary magnetic focusing. We examine optimization of a variety of parameters, study the nonlinear dynamics in the twin helix channel and consider possible methods of aberration correction.

Beta-phenylethylamine stimulates striatal acetylcholine release through activation of the AMPA glutamatergic pathway.

PubMed

Ishida, Kota; Murata, Mikio; Kato, Masatoshi; Utsunomiya, Iku; Hoshi, Keiko; Taguchi, Kyoji

2005-09-01

Using an in vivo intra-striatal microdialysis technique, we examined the effects of systemically administered beta-phenylethylamine (beta-PEA), a psychomotor stimulating trace amine, on striatal acetylcholine release in freely moving rats. Infusion of N-methyl-D-aspartic acid (NMDA; 10(-5) M) significantly increased acetylcholine release. In addition, locally applied amino-3-hydroxy-5-methylisozasole-4-propionic acid (AMPA; 10(-5) M) significantly increased acetylcholine release in the striatum. Intra-striatal application of 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX; 10(-5) M), an AMPA-type glutamatergic receptor antagonist, had little effect on acetylcholine release, while application of MK-801 (10(-5) M, 10(-6) M), an NMDA-type glutamatergic receptor antagonist, significantly reduced acetylcholine release. Acetylcholine within striatal perfusate was significantly increased by intraperitoneal administration of beta-PEA in a dose-dependent manner. This increase in acetylcholine release was completely blocked by application of CNQX (10(-5) M) through the microdialysis probe into the striatum. However, increased acetylcholine response to systemic beta-PEA was unaltered by addition of MK-801 to the perfusion medium. These results suggest a regulatory function of beta-PEA, mediated by AMPA-type glutamatergic receptors, on the release of acetylcholine in the rat striatum.

"ToothPIC": An Interactive Application for Teaching Oral Anatomy

ERIC Educational Resources Information Center

Javaid, Maria; Ashrafi, Seema; Zefran, Mil; Steinberg, Arnold D.

2016-01-01

This paper describes the development and evaluation of an interactive educational program, "Tooth" "P"lacement and "I"dentification "C"oach ("ToothPIC"). The program uses a game-based learning paradigm and 3D visualization techniques to allow first year dentistry and hygiene students to get…

ENHANCED FORMATION OF DIOXINS AND FURANS FROM COMBUSTION DEVICES BY ADDITION OF TRACE QUANTITIES OF BROMINE

EPA Science Inventory

Past pilot-scale experimental studies have shown a dramatic increase in the formation of certain chlorinated products of incomplete combustion (PICs) caused by the addition of trace amounts of bromine (Br). Emissions of trichloroethylene and tetrachloorethylene, generated as PICs...

Spatial and temporal variability in coccolithophore abundance and production of PIC and POC in the NE subarctic Pacific during El Niño (1998), La Niña (1999) and 2000

NASA Astrophysics Data System (ADS)

Lipsen, M. S.; Crawford, D. W.; Gower, J.; Harrison, P. J.

2007-10-01

Seasonal variations in coccolithophore abundance, chlorophyll, nutrients and production of particulate organic and inorganic carbon (POC and PIC) were determined along a coastal to oceanic east-west transect (Line P) culminating at Ocean Station Papa in the northeastern subarctic Pacific between 1998 and 2000. Offshore stations generally exhibited low seasonality in chlorophyll concentrations, with moderate seasonality in POC production. Near shelf stations showed a similar pattern to offshore stations, but were also characterized by sporadic events of higher POC productivity. During the 1998 El Niño, June was characterized by low chlorophyll and POC productivity along the transect, presumably as a result of depleted surface nitrate. In contrast, during the 1999 La Niña, and in 2000, higher POC productivity and surface nitrate occurred along the transect in June. Chlorophyll and POC productivity were similar in late summer in all 3 years. The coccolithophore population was usually numerically dominated by Emiliania huxleyi, particularly in June. Along the transect, abundance of coccolithophores was much higher in June during the 1998 El Niño (mean of 221 cells ml -1) than in the 1999 La Niña (mean of 40 cells ml -1), with their abundance in late summers of both years being very low. Abundances were even higher along the transect in June and the late summer of 2000 with sporadic ‘blooms’ of >1000 cells ml -1 at some stations (cruise averages 395 and 552 cell ml -1, respectively). Production rates of PIC did not consistently correlate with areas of high coccolithophore abundance. PIC production was high (100-250 mg C m -2 d -1) along the transect during June 1998, and low (1-40 mg C m -2 d -1) during both winters, June 1999 and during late summers of 1998 and 1999. The year 2000 was more complicated, with high rates of PIC production accompanying high abundance of coccolithophores in late summer, but lower rates of PIC production accompanying high coccolithophore numbers in June. Our data suggest that the abundance of coccolithophores and the production rates of PIC in the subarctic are higher than previously thought. Occasional PIC:POC production ratios of 1 or greater in 1998 and 2000 suggest that coccolithophores in this region could have a significant impact on the efficiency of the biological carbon pump.

A moderate increase in ambient temperature modulates the Atlantic cod (Gadus morhua) spleen transcriptome response to intraperitoneal viral mimic injection

PubMed Central

2012-01-01

Background Atlantic cod (Gadus morhua) reared in sea-cages can experience large variations in temperature, and these have been shown to affect their immune function. We used the new 20K Atlantic cod microarray to investigate how a water temperature change which, simulates that seen in Newfoundland during the spring-summer (i.e. from 10°C to 16°C, 1°C increase every 5 days) impacted the cod spleen transcriptome response to the intraperitoneal injection of a viral mimic (polyriboinosinic polyribocytidylic acid, pIC). Results The temperature regime alone did not cause any significant increases in plasma cortisol levels and only minor changes in spleen gene transcription. However, it had a considerable impact on the fish spleen transcriptome response to pIC [290 and 339 significantly differentially expressed genes between 16°C and 10°C at 6 and 24 hours post-injection (HPI), respectively]. Seventeen microarray-identified transcripts were selected for QPCR validation based on immune-relevant functional annotations. Fifteen of these transcripts (i.e. 88%), including DHX58, STAT1, IRF7, ISG15, RSAD2 and IκBα, were shown by QPCR to be significantly induced by pIC. Conclusions The temperature increase appeared to accelerate the spleen immune transcriptome response to pIC. We found 41 and 999 genes differentially expressed between fish injected with PBS vs. pIC at 10°C and sampled at 6HPI and 24HPI, respectively. In contrast, there were 656 and 246 genes differentially expressed between fish injected with PBS vs. pIC at 16°C and sampled at 6HPI and 24HPI, respectively. Our results indicate that the modulation of mRNA expression of genes belonging to the NF-κB and type I interferon signal transduction pathways may play a role in controlling temperature-induced changes in the spleen’s transcript expression response to pIC. Moreover, interferon effector genes such as ISG15 and RSAD2 were differentially expressed between fish injected with pIC at 10°C vs. 16°C at 6HPI. These results substantially increase our understanding of the genes and molecular pathways involved in the negative impacts of elevated ambient temperature on fish health, and may also be valuable to our understanding of how accelerated global climate change could impact cold-water marine finfish species. PMID:22928584

A moderate increase in ambient temperature modulates the Atlantic cod (Gadus morhua) spleen transcriptome response to intraperitoneal viral mimic injection.

PubMed

Hori, Tiago S; Gamperl, A Kurt; Booman, Marije; Nash, Gordon W; Rise, Matthew L

2012-08-28

Atlantic cod (Gadus morhua) reared in sea-cages can experience large variations in temperature, and these have been shown to affect their immune function. We used the new 20K Atlantic cod microarray to investigate how a water temperature change which, simulates that seen in Newfoundland during the spring-summer (i.e. from 10°C to 16°C, 1°C increase every 5 days) impacted the cod spleen transcriptome response to the intraperitoneal injection of a viral mimic (polyriboinosinic polyribocytidylic acid, pIC). The temperature regime alone did not cause any significant increases in plasma cortisol levels and only minor changes in spleen gene transcription. However, it had a considerable impact on the fish spleen transcriptome response to pIC [290 and 339 significantly differentially expressed genes between 16°C and 10°C at 6 and 24 hours post-injection (HPI), respectively]. Seventeen microarray-identified transcripts were selected for QPCR validation based on immune-relevant functional annotations. Fifteen of these transcripts (i.e. 88%), including DHX58, STAT1, IRF7, ISG15, RSAD2 and IκBα, were shown by QPCR to be significantly induced by pIC. The temperature increase appeared to accelerate the spleen immune transcriptome response to pIC. We found 41 and 999 genes differentially expressed between fish injected with PBS vs. pIC at 10°C and sampled at 6HPI and 24HPI, respectively. In contrast, there were 656 and 246 genes differentially expressed between fish injected with PBS vs. pIC at 16°C and sampled at 6HPI and 24HPI, respectively. Our results indicate that the modulation of mRNA expression of genes belonging to the NF-κB and type I interferon signal transduction pathways may play a role in controlling temperature-induced changes in the spleen's transcript expression response to pIC. Moreover, interferon effector genes such as ISG15 and RSAD2 were differentially expressed between fish injected with pIC at 10°C vs. 16°C at 6HPI. These results substantially increase our understanding of the genes and molecular pathways involved in the negative impacts of elevated ambient temperature on fish health, and may also be valuable to our understanding of how accelerated global climate change could impact cold-water marine finfish species.

Chromium Picolinate Does Not Improve Key Features of Metabolic Syndrome in Obese Nondiabetic Adults

PubMed Central

Iqbal, Nayyar; Cardillo, Serena; Volger, Sheri; Bloedon, LeAnne T.; Anderson, Richard A.; Boston, Raymond

2009-01-01

Abstract Background The use of chromium-containing dietary supplements is widespread among patients with type 2 diabetes. Chromium's effects in patients at high risk for developing diabetes, especially those with metabolic syndrome, is unknown. The objective of this study was to determine the effects of chromium picolinate (CrPic) on glucose metabolism in patients with metabolic syndrome. Method A double-blind, placebo-controlled, randomized trial was conducted at a U.S. academic medical center. Sixty three patients with National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP III)-defined metabolic syndrome were included. The primary end point was a change in the insulin sensitivity index derived from a frequently sampled intravenous glucose tolerance test. Prespecified secondary end points included changes in other measurements of glucose metabolism, oxidative stress, fasting serum lipids, and high sensitivity C-reactive protein. Results After 16 weeks of CrPic treatment, there was no significant change in insulin sensitivity index between groups (P = 0.14). However, CrPic increased acute insulin response to glucose (P = 0.02). CrPic had no significant effect on other measures of glucose metabolism, body weight, serum lipids, or measures of inflammation and oxidative stress. Conclusion CrPic at 1000 μg/day does not improve key features of the metabolic syndrome in obese nondiabetic patients. PMID:19422140

Numerical fatigue analysis of premolars restored by CAD/CAM ceramic crowns.

PubMed

Homaei, Ehsan; Jin, Xiao-Zhuang; Pow, Edmond Ho Nang; Matinlinna, Jukka Pekka; Tsoi, James Kit-Hon; Farhangdoost, Khalil

2018-04-10

The purpose of this study was to estimate the fatigue life of premolars restored with two dental ceramics, lithium disilicate (LD) and polymer infiltrated ceramic (PIC) using the numerical method and compare it with the published in vitro data. A premolar restored with full-coverage crown was digitized. The volumetric shape of tooth tissues and crowns were created in Mimics ® . They were transferred to IA-FEMesh for mesh generation and the model was analyzed with Abaqus. By combining the stress distribution results with fatigue stress-life (S-N) approach, the lifetime of restored premolars was predicted. The predicted lifetime was 1,231,318 cycles for LD with fatigue load of 1400N, while the one for PIC was 475,063 cycles with the load of 870N. The peak value of maximum principal stress occurred at the contact area (LD: 172MPa and PIC: 96MPa) and central fossa (LD: 100MPa and PIC: 64MPa) for both ceramics which were the most seen failure areas in the experiment. In the adhesive layer, the maximum shear stress was observed at the shoulder area (LD: 53.6MPa and PIC: 29MPa). The fatigue life and failure modes of all-ceramic crown determined by the numerical method seem to correlate well with the previous experimental study. Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.

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

Lee, S.Y.; Valenti, J.C.; Tabor, D.G.

The use of waste wood as fuel for producing energy is a promising supplement to fossil fuels for many regions of the country. In addition to recovering energy and conserving landfill space, burning waste wood fuels also mitigates global warming created by fossil fuel combustion. However, the environmental consequences resulting from emissions generated by combustion of waste wood which contains paints, resins, or preservatives are not well understood. The combustion of waste wood treated with chemicals may produce potentially hazardous products of incomplete combustion (PIC) emissions such as dioxins. Characterization of PIC emissions from the combustion of waste wood previouslymore » treated with pentachlorophenol is reported in this study. Utility poles and crossbars are typically treated with a preservative such as pentachlorophenol in order to prolong their service life. They are disposed of by landfilling after being taken out of service. Burning such wood waste in boilers for steam generation becomes an increasingly attractive waste management alternative as it contains substantial energy value and reduces landfilling costs. Pilot-scale combustion tests were conducted under well controlled conditions in a 0.58 MW (2 million Btu/hr) combustor to compare PIC emissions from burning untreated wood and pentachlorophenol-treated wood. Sampling and analyses for a wide variety of PICs, including volatile organic compounds (VOCs), semivolatile organic compounds, and dioxins and furans, were performed to assess the effect of pentachlorophenol preservative present in wood on PIC emissions.« less

Protective effects of resveratrol and its analogs on age-related macular degeneration in vitro.

PubMed

Kang, Jung-Hwan; Choung, Se-Young

2016-12-01

Damage of retinal pigment epithelial (RPE) cells by A2E may be critical for age-related macular degeneration (AMD) management. Accumulation and photooxidation of A2E are known to be one of the critical causes in AMD. Here, we evaluated the protective effect of resveratrol (RES), piceatannol (PIC) and RES glycones on blue-light-induced RPE cell death caused by A2E photooxidation. A2E treatment followed by blue light exposure caused significant damages on human RPE cells (ARPE-19). But the damages were attenuated by post- and pre-treatment of RES and PIC in our in vitro models. The results of cell free system and FAB-MS analysis clearly showed that the reduction of A2E by blue light exposure was significantly rescued, and that oxidized forms of A2E were significantly reduced by RES or PIC treatment. Besides, RES or PIC inhibited the intracellular accumulation of A2E. Not only RES and PIC but RES glycones showed protection of ARPE-19 cells against A2E and blue-light-induced photo-damage. These findings demonstrate that RES and its analogs may have protective effects against A2E and blue-light-induced ARPE-19 cell death through regulation of A2E accumulation as well as photooxidation of A2E. Thus RES and its analogs may be beneficial for AMD treatment.

Is an absolute level of cortical beta suppression required for proper movement? Magnetoencephalographic evidence from healthy aging.

PubMed

Heinrichs-Graham, Elizabeth; Wilson, Tony W

2016-07-01

Previous research has connected a specific pattern of beta oscillatory activity to proper motor execution, but no study to date has directly examined how resting beta levels affect motor-related beta oscillatory activity in the motor cortex. Understanding this relationship is imperative to determining the basic mechanisms of motor control, as well as the impact of pathological beta oscillations on movement execution. In the current study, we used magnetoencephalography (MEG) and a complex movement paradigm to quantify resting beta activity and movement-related beta oscillations in the context of healthy aging. We chose healthy aging as a model because preliminary evidence suggests that beta activity is elevated in older adults, and thus by examining older and younger adults we were able to naturally vary resting beta levels. To this end, healthy younger and older participants were recorded during motor performance and at rest. Using beamforming, we imaged the peri-movement beta event-related desynchronization (ERD) and extracted virtual sensors from the peak voxels, which enabled absolute and relative beta power to be assessed. Interestingly, absolute beta power during the pre-movement baseline was much stronger in older relative to younger adults, and older adults also exhibited proportionally large beta desynchronization (ERD) responses during motor planning and execution compared to younger adults. Crucially, we found a significant relationship between spontaneous (resting) beta power and beta ERD magnitude in both primary motor cortices, above and beyond the effects of age. A similar link was found between beta ERD magnitude and movement duration. These findings suggest a direct linkage between beta reduction during movement and spontaneous activity in the motor cortex, such that as spontaneous beta power increases, a greater reduction in beta activity is required to execute movement. We propose that, on an individual level, the primary motor cortices have an absolute threshold of beta power that must be reached in order to move, and that an inability to suppress beta power to this threshold results in an increase in movement duration. Copyright © 2016 Elsevier Inc. All rights reserved.

Particle-in-cell simulations of bounded plasma discharges applied to low pressure high density sources and positive columns

NASA Astrophysics Data System (ADS)

Kawamura, Emi

Particle-in-cell (PIC) simulations of bounded plasma discharges are attractive because the fields and the particle motion can be obtained self-consistently from first principles. Thus, we can accurately model a wide range of nonlocal and kinetic behavior. The only disadvantage is that PIC may be computationally expensive compared to other methods. Fluid codes, for example, may run faster but make assumptions about the bulk plasma velocity distributions and ignore kinetic effects. In Chapter 1, we demonstrate methods of accelerating PIC simulations of bounded plasma discharges. We find that a combination of physical and numerical methods makes run-times for PIC codes much more competitive with other types of codes. In processing plasmas, the ion energy distributions (IEDs) arriving at the wafer target are crucial in determining ion anisotropy and etch rates. The current trend for plasma reactors is towards lower gas pressure and higher plasma density. In Chapter 2, we review and analyze IEDs arriving at the target of low pressure high density rf plasma reactors. In these reactors, the sheath is typically collisionless. We then perform PIC simulations of collisionless rf sheaths and find that the key parameter governing the shape of the TED at the wafer is the ratio of the ion transit time across the sheath over the rf period. Positive columns are the source of illumination in fluorescent mercury-argon lamps. The efficiency of light production increases with decreasing gas pressure and decreasing discharge radius. Most current lamp software is based on the local concept even though low pressure lighting discharges tend to be nonlocal. In Chapter 3, we demonstrate a 1d3v radial PIC model to conduct nonlocal kinetic simulations of low pressure, small radius positive columns. When compared to other available codes, we find that our PIC code makes the least approximations and assumptions and is accurate and stable over a wider parameter range. We analyze the PIC simulation results in detail and find that the radial electron heat flow, which is neglected in local models, plays a major role in maintaining the global power balance. In Chapter 2, we focused on the sheaths of low pressure high density plasma reactors. In Chapter 4, we extend our study to the bulk and presheaths. Typical industrial plasma reactors often use gases with complex chemistries which tend to generate discharges containing negative ions. For high density electronegative plasmas with low gas pressure, we expect Coulomb collisions between positive and negative ions to dominate over collisions between ions and neutrals. We incorporate a Coulomb collision model into our PIC code to study the effect of this ion-ion Coulomb scattering. We find that the Coulomb collisions between the positive and negative ions significantly modify the negative ion flux, density and kinetic energy profiles.

The Whole PIC Catalog: Organization, Planning and Service Delivery Options under JTPA.

ERIC Educational Resources Information Center

National Alliance of Business, Inc., Washington, DC.

This handbook illustrates and discusses organizational options for the delivery of employment and training services within service delivery areas (SDAs) mandated by the Job Training Partnership Act (JTPA) of 1982. Addressed primarily to members of private industry councils (PICs), representatives of local governments, and employment and training…

Democracy Now? Race, Education, and Black Self-Determination

ERIC Educational Resources Information Center

Dixson, Adrienne

2011-01-01

Background/Context: The Supreme Court's June 2007 decision on the Parents Involved in Community Schools v. Seattle School District No. 1 (PICS) provides an important context for school districts and educational policy makers as they consider the role of race in school assignment. The PICS decision has been described as essentially…

UCLA Final Technical Report for the "Community Petascale Project for Accelerator Science and Simulation”.

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

Mori, Warren

The UCLA Plasma Simulation Group is a major partner of the “Community Petascale Project for Accelerator Science and Simulation”. This is the final technical report. We include an overall summary, a list of publications, progress for the most recent year, and individual progress reports for each year. We have made tremendous progress during the three years. SciDAC funds have contributed to the development of a large number of skeleton codes that illustrate how to write PIC codes with a hierarchy of parallelism. These codes cover 2D and 3D as well as electrostatic solvers (which are used in beam dynamics codesmore » and quasi-static codes) and electromagnetic solvers (which are used in plasma based accelerator codes). We also used these ideas to develop a GPU enabled version of OSIRIS. SciDAC funds were also contributed to the development of strategies to eliminate the Numerical Cerenkov Instability (NCI) which is an issue when carrying laser wakefield accelerator (LWFA) simulations in a boosted frame and when quantifying the emittance and energy spread of self-injected electron beams. This work included the development of a new code called UPIC-EMMA which is an FFT based electromagnetic PIC code and to new hybrid algorithms in OSIRIS. A new hybrid (PIC in r-z and gridless in φ) algorithm was implemented into OSIRIS. In this algorithm the fields and current are expanded into azimuthal harmonics and the complex amplitude for each harmonic is calculated separately. The contributions from each harmonic are summed and then used to push the particles. This algorithm permits modeling plasma based acceleration with some 3D effects but with the computational load of an 2D r-z PIC code. We developed a rigorously charge conserving current deposit for this algorithm. Very recently, we made progress in combining the speed up from the quasi-3D algorithm with that from the Lorentz boosted frame. SciDAC funds also contributed to the improvement and speed up of the quasi-static PIC code QuickPIC. We have also used our suite of PIC codes to make scientific discovery. Highlights include supporting FACET experiments which achieved the milestones of showing high beam loading and energy transfer efficiency from a drive electron beam to a witness electron beam and the discovery of a self-loading regime a for high gradient acceleration of a positron beam. Both of these experimental milestones were published in Nature together with supporting QuickPIC simulation results. Simulation results from QuickPIC were used on the cover of Nature in one case. We are also making progress on using highly resolved QuickPIC simulations to show that ion motion may not lead to catastrophic emittance growth for tightly focused electron bunches loaded into nonlinear wakefields. This could mean that fully self-consistent beam loading scenarios are possible. This work remains in progress. OSIRIS simulations were used to discover how 200 MeV electron rings are formed in LWFA experiments, on how to generate electrons that have a series of bunches on nanometer scale, and how to transport electron beams from (into) plasma sections into (from) conventional beam optic sections.« less

Pharmacological analysis of ecto-ATPase inhibition: evidence for combined enzyme inhibition and receptor antagonism in P2X-purinoceptor ligands.

PubMed

Crack, B E; Beukers, M W; McKechnie, K C; Ijzerman, A P; Leff, P

1994-12-01

1. Previous studies have shown that suramin and FPL 66301 are competitive antagonists at the P2X-purinoceptor in the rabbit ear artery. Those studies employed alpha,beta-methylene ATP, a poorly hydrolysable ATP analogue, as the agonist. In this study these compounds have been tested using ATP as the agonist. 2. Suramin, in the concentration range 30-1000 microM, potentiated the contractile effects of ATP, producing a 3-fold leftward shift of the ATP E/[A] curves. FPL 66301, in the concentration range 100-1000 microM, produced a significant but small (approximately 3-fold) rightward shift of the ATP curves. These results are in marked contrast with previous studies using alpha,beta-methylene ATP in which 30-fold rightward shifts were achieved using the same concentration ranges of suramin and FPL 66301. 3. Suramin and FPL 66301 were tested as ecto-ATPase inhibitors in a human blood cell assay. Suramin inhibited the enzyme with a pIC50 of 4.3, FPL 66301 with a pIC50 of 3.3. 4. The pharmacological data were analysed using a theoretical model describing the action of a compound with dual enzyme inhibitory and receptor antagonistic properties on the effects of an agonist susceptible to enzymatic degradation. The model was found to fit the data well using the known pKB estimates for suramin and FPL 66301 and similar relative (but not absolute) pK1 estimates to those obtained for the compounds in the enzyme assay. 5. From this analysis it was concluded that the limited shifts of ATP E/[A] curves produced by suramin and FPL 66301 were the result of 'self-cancellation' of the potentiating (enzyme inhibitory) and rightward-shifting (receptor antagonistic) properties.6. The analysis also indicated that the presence of ecto-ATPase activity in the rabbit ear artery preparation has a marked effect on the apparent potency of ATP. The experimental p[A50] was 3.4,whereas the 'true' value, that is the value which would be obtained in the absence of ecto-ATPase activity, was 6.0, some 400-fold higher.7 Two conclusions are drawn from this study. Firstly, caution must be exercised in the use of suramin and FPL 66301 as tools for receptor classification. Absence of overt antagonism by these compounds when metabolically unstable agonists are used could lead to erroneous claims for receptor subtypes.Secondly, the agonist potency order currently used to designate P2X- purinoceptors may require modification.

Visuotactile motion congruence enhances gamma-band activity in visual and somatosensory cortices.

PubMed

Krebber, Martin; Harwood, James; Spitzer, Bernhard; Keil, Julian; Senkowski, Daniel

2015-08-15

When touching and viewing a moving surface our visual and somatosensory systems receive congruent spatiotemporal input. Behavioral studies have shown that motion congruence facilitates interplay between visual and tactile stimuli, but the neural mechanisms underlying this interplay are not well understood. Neural oscillations play a role in motion processing and multisensory integration. They may also be crucial for visuotactile motion processing. In this electroencephalography study, we applied linear beamforming to examine the impact of visuotactile motion congruence on beta and gamma band activity (GBA) in visual and somatosensory cortices. Visual and tactile inputs comprised of gratings that moved either in the same or different directions. Participants performed a target detection task that was unrelated to motion congruence. While there were no effects in the beta band (13-21Hz), the power of GBA (50-80Hz) in visual and somatosensory cortices was larger for congruent compared with incongruent motion stimuli. This suggests enhanced bottom-up multisensory processing when visual and tactile gratings moved in the same direction. Supporting its behavioral relevance, GBA was correlated with shorter reaction times in the target detection task. We conclude that motion congruence plays an important role for the integrative processing of visuotactile stimuli in sensory cortices, as reflected by oscillatory responses in the gamma band. Copyright © 2015 Elsevier Inc. All rights reserved.

Performance and capacity analysis of Poisson photon-counting based Iter-PIC OCDMA systems.

PubMed

Li, Lingbin; Zhou, Xiaolin; Zhang, Rong; Zhang, Dingchen; Hanzo, Lajos

2013-11-04

In this paper, an iterative parallel interference cancellation (Iter-PIC) technique is developed for optical code-division multiple-access (OCDMA) systems relying on shot-noise limited Poisson photon-counting reception. The novel semi-analytical tool of extrinsic information transfer (EXIT) charts is used for analysing both the bit error rate (BER) performance as well as the channel capacity of these systems and the results are verified by Monte Carlo simulations. The proposed Iter-PIC OCDMA system is capable of achieving two orders of magnitude BER improvements and a 0.1 nats of capacity improvement over the conventional chip-level OCDMA systems at a coding rate of 1/10.

Characterization of a trinuclear ruthenium species in catalytic water oxidation by Ru(bda)(pic)2 in neutral media.

PubMed

Zhang, Biaobiao; Li, Fei; Zhang, Rong; Ma, Chengbing; Chen, Lin; Sun, Licheng

2016-06-30

A Ru(III)-O-Ru(IV)-O-Ru(III) type trinuclear species was crystallographically characterized in water oxidation by Ru(bda)(pic)2 (H2bda = 2,2'-bipyridine-6,6'-dicarboxylic acid; pic = 4-picoline) under neutral conditions. The formation of a ruthenium trimer due to the reaction of Ru(IV)[double bond, length as m-dash]O with Ru(II)-OH2 was fully confirmed by chemical, electrochemical and photochemical methods. Since the oxidation of the trimer was proposed to lead to catalyst decomposition, the photocatalytic water oxidation activity was rationally improved by the suppression of the formation of the trimer.

Photonic integrated circuits: new challenges for lithography

NASA Astrophysics Data System (ADS)

Bolten, Jens; Wahlbrink, Thorsten; Prinzen, Andreas; Porschatis, Caroline; Lerch, Holger; Giesecke, Anna Lena

2016-10-01

In this work routes towards the fabrication of photonic integrated circuits (PICs) and the challenges their fabrication poses on lithography, such as large differences in feature dimension of adjacent device features, non-Manhattan-type features, high aspect ratios and significant topographic steps as well as tight lithographic requirements with respect to critical dimension control, line edge roughness and other key figures of merit not only for very small but also for relatively large features, are highlighted. Several ways those challenges are faced in today's low-volume fabrication of PICs, including the concept multi project wafer runs and mix and match approaches, are presented and possible paths towards a real market uptake of PICs are discussed.

CPIC: a curvilinear Particle-In-Cell code for plasma-material interaction studies

NASA Astrophysics Data System (ADS)

Delzanno, G.; Camporeale, E.; Moulton, J. D.; Borovsky, J. E.; MacDonald, E.; Thomsen, M. F.

2012-12-01

We present a recently developed Particle-In-Cell (PIC) code in curvilinear geometry called CPIC (Curvilinear PIC) [1], where the standard PIC algorithm is coupled with a grid generation/adaptation strategy. Through the grid generator, which maps the physical domain to a logical domain where the grid is uniform and Cartesian, the code can simulate domains of arbitrary complexity, including the interaction of complex objects with a plasma. At present the code is electrostatic. Poisson's equation (in logical space) can be solved with either an iterative method based on the Conjugate Gradient (CG) or the Generalized Minimal Residual (GMRES) coupled with a multigrid solver used as a preconditioner, or directly with multigrid. The multigrid strategy is critical for the solver to perform optimally or nearly optimally as the dimension of the problem increases. CPIC also features a hybrid particle mover, where the computational particles are characterized by position in logical space and velocity in physical space. The advantage of a hybrid mover, as opposed to more conventional movers that move particles directly in the physical space, is that the interpolation of the particles in logical space is straightforward and computationally inexpensive, since one does not have to track the position of the particle. We will present our latest progress on the development of the code and document the code performance on standard plasma-physics tests. Then we will present the (preliminary) application of the code to a basic dynamic-charging problem, namely the charging and shielding of a spherical spacecraft in a magnetized plasma for various level of magnetization and including the pulsed emission of an electron beam from the spacecraft. The dynamical evolution of the sheath and the time-dependent current collection will be described. This study is in support of the ConnEx mission concept to use an electron beam from a magnetospheric spacecraft to trace magnetic field lines from the magnetosphere to the ionosphere [2]. [1] G.L. Delzanno, E. Camporeale, "CPIC: a new Particle-in-Cell code for plasma-material interaction studies", in preparation (2012). [2] J.E. Borovsky, D.J. McComas, M.F. Thomsen, J.L. Burch, J. Cravens, C.J. Pollock, T.E. Moore, and S.B. Mende, "Magnetosphere-Ionosphere Observatory (MIO): A multisatellite mission designed to solve the problem of what generates auroral arcs," Eos. Trans. Amer. Geophys. Union 79 (45), F744 (2000).

Mutual Injection Locking of Monolithically Integrated Coupled-Cavity DBR Lasers

DOE PAGES

Tauke-Pedretti, Anna; Vawter, G. Allen; Skogen, Erik J.; ...

2011-07-01

We present a photonic integrated circuit (PIC) composed of two strongly coupled distributed Bragg reflector (DBR) lasers. This PIC utilizes the dynamics of mutual injection locking to increase the relaxation resonance frequency from 3 GHz to beyond 30 GHz. Mutual injection-locking and external injection-locking operation are then compared.

47 CFR 64.4002 - Notification obligations of LECs.

Code of Federal Regulations, 2012 CFR

2012-10-01

... and processing a PIC selection submitted by a customer and placing the customer on the network of the...-submitted PIC order (i.e., mirror image of the original order), unless otherwise specified by this paragraph... request (i.e., the mirror image of the original request), along with the specific reason(s) why the...

47 CFR 64.4002 - Notification obligations of LECs.

Code of Federal Regulations, 2013 CFR

2013-10-01

... and processing a PIC selection submitted by a customer and placing the customer on the network of the...-submitted PIC order (i.e., mirror image of the original order), unless otherwise specified by this paragraph... request (i.e., the mirror image of the original request), along with the specific reason(s) why the...

47 CFR 64.4002 - Notification obligations of LECs.

Code of Federal Regulations, 2014 CFR

2014-10-01

... and processing a PIC selection submitted by a customer and placing the customer on the network of the...-submitted PIC order (i.e., mirror image of the original order), unless otherwise specified by this paragraph... request (i.e., the mirror image of the original request), along with the specific reason(s) why the...

47 CFR 64.4002 - Notification obligations of LECs.

Code of Federal Regulations, 2011 CFR

2011-10-01

... and processing a PIC selection submitted by a customer and placing the customer on the network of the...-submitted PIC order (i.e., mirror image of the original order), unless otherwise specified by this paragraph... request (i.e., the mirror image of the original request), along with the specific reason(s) why the...

78 FR 42323 - Pilot Certification and Qualification Requirements for Air Carrier Operations

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-15

... sufficient. \\4\\ In addition, military PIC time (up to 500 hours) in a multiengine turbine-powered, fixed-wing... aerodynamic stall (insufficient airflow over the wings). The flightcrew's response to the stall warning system.... Military PIC time in a multiengine turbine-powered, fixed-wing airplane in an operation requiring more than...

The PIC Youth Primer: Improving JTPA Programs for Youth.

ERIC Educational Resources Information Center

Snedeker, Bonnie; And Others

This guide for Private Industry Council (PIC) officers, members, and staff is written to assist in planning and overseeing effective programs for youth at risk in the local labor market using resources allocated under the Job Training Partnership Act (JTPA). Section I takes a broad view of the problem of building effective employability…

Simulation of stimulated Brillouin scattering and stimulated Raman scattering in shock ignition

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

Hao, L.; Li, J.; Liu, W. D.

2016-04-15

We study stimulated Brillouin scattering (SBS) and stimulated Raman scattering (SRS) in shock ignition by comparing fluid and particle-in-cell (PIC) simulations. Under typical parameters for the OMEGA experiments [Theobald et al., Phys. Plasmas 19, 102706 (2012)], a series of 1D fluid simulations with laser intensities ranging between 2 × 10{sup 15} and 2 × 10{sup 16 }W/cm{sup 2} finds that SBS is the dominant instability, which increases significantly with the incident intensity. Strong pump depletion caused by SBS and SRS limits the transmitted intensity at the 0.17n{sub c} to be less than 3.5 × 10{sup 15 }W/cm{sup 2}. The PIC simulations show similar physics but with higher saturationmore » levels for SBS and SRS convective modes and stronger pump depletion due to higher seed levels for the electromagnetic fields in PIC codes. Plasma flow profiles are found to be important in proper modeling of SBS and limiting its reflectivity in both the fluid and PIC simulations.« less

A role for the interoceptive insular cortex in the consolidation of learned fear.

PubMed

Casanova, José Patricio; Madrid, Carlos; Contreras, Marco; Rodríguez, María; Vasquez, Mónica; Torrealba, Fernando

2016-01-01

A growing body of evidence suggests that learned fear may be related to the function of the interoceptive insular cortex. Using an auditory fear conditioning paradigm in rats, we show that the inactivation of the posterior insular cortex (pIC), the target of the interoceptive thalamus, prior to training produced a marked reduction in fear expression tested 24h later. Accordingly, post-training anisomycin infused immediately, but not 6h after, also reduced fear expression tested the following day, supporting a role for the pIC in consolidation of fear memory. The long-term (ca. a week) and reversible inactivation of the pIC with the sodium channel blocker neosaxitoxin, immediately after fear memory reactivation induced a progressive decrease in the behavioral expression of conditioned fear. In turn, we observed that fear memory reactivation is accompanied by an enhanced expression of Fos and Zif268, early genes involved in neural activity and plasticity. Taken together these data indicate that the pIC is involved in the regulation of fear memories. Copyright © 2015 Elsevier B.V. All rights reserved.

Palaeotsunamis in the Pacific Islands

USGS Publications Warehouse

Goff, J.; Chague-Goff, C.; Dominey-Howes, D.; McAdoo, B.; Cronin, S.; Bonte-Grapetin, Michael; Nichol, S.; Horrocks, M.; Cisternas, M.; Lamarche, G.; Pelletier, B.; Jaffe, B.; Dudley, W.

2011-01-01

The recent 29 September 2009 South Pacific and 27 February 2010 Chilean events are a graphic reminder that the tsunami hazard and risk for the Pacific Ocean region should not be forgotten. Pacific Islands Countries (PICs) generally have short (<150 years) historic records, which means that to understand their tsunami hazard and risk researchers must study evidence for prehistoric events. However, our current state of knowledge of palaeotsunamis in PICs as opposed to their circum-Pacific counterparts is minimal at best. We briefly outline the limited extent of our current knowledge and propose an innovative methodology for future research in the Pacific. Each PIC represents a point source of information in the Pacific Ocean and this would allow their palaeotsunami records to be treated akin to palaeo-DART?? (Deep-ocean Assessment and Reporting of Tsunamis) buoys. Contemporaneous palaeotsunamis from local, regional and distant sources could be identified by using the spatial distribution of island records throughout the Pacific Ocean in conjunction with robust event chronologies. This would be highly innovative and, more importantly, would help provide the building blocks necessary to achieve more meaningful disaster risk reduction for PICs. ?? 2010 Elsevier B.V.

Nutritional supplement chromium picolinate causes sterility and lethal mutations in Drosophila melanogaster

PubMed Central

Hepburn, Dion D. D.; Xiao, Jiarong; Bindom, Sharell; Vincent, John B.; O'Donnell, Janis

2003-01-01

The nutritional dietary supplement chromium picolinate, [Cr(pic)3], has gained much notoriety as a safe supplement that supposedly promotes fat loss and muscle enhancement in humans. Thus, a significant industry has materialized around the incorporation of [Cr(pic)3] in many sports foods and drinks and a variety of weight loss products. However, in vitro studies have suggested that low levels of [Cr(pic)3] in the presence of biological reducing agents can catalytically generate reactive oxygen species, and recent in vivo studies have detected oxidative damage in rats receiving the supplement. The potential deleterious in vivo effects of this activity were examined by using Drosophila melanogaster. [Cr(pic)3], but not CrCl3, at levels of 260 μg Cr/kg food or less were found to lower the success rate of pupation and eclosion and to arrest development of pupae in a concentration dependent fashion. X-linked lethal analysis indicates that the supplement greatly enhances the rate of appearance of lethal mutations and dominant female sterility. PMID:12649323

Evaluation and comparison of indentation ultrasound biomicroscopy gonioscopy in relative pupillary block, peripheral anterior synechia, and plateau iris configuration.

PubMed

Matsunaga, Koichi; Ito, Kunio; Esaki, Koji; Sugimoto, Kota; Sano, Toru; Miura, Katsuya; Sasoh, Mikio; Uji, Yukitaka

2004-12-01

To evaluate and compare the findings and changes of the anterior chamber angle configuration with indentation ultrasound biomicroscopy (UBM) gonioscopy in relative pupillary block (RPB), peripheral anterior synechia (PAS), and plateau iris configuration (PIC). This study included 73 eyes of 52 patients with RPB (n = 26), PAS (n = 21), or PIC (n = 26). First, a conventional UBM scan was performed using a normal size standard eye cup before indentation. Then, for indentation UBM gonioscopy, scans were performed using a new eye cup that we designed. For evaluation of the angle, angle opening distance 500 and angle recess area were recorded and evaluated with regard to the effect of expansion on the anterior chamber angle. Indentation UBM gonioscopy showed the characteristic images in each of the eyes. The angle of all examined eyes was significantly widened with indentation (P < 0.01). The angle changes in eyes with RPB were significantly greater than in eyes with PAS or PIC (P < 0.01). Indentation UBM gonioscopy is a very useful method for observing the angle and diagnosis of RPB, PAS, and PIC.

Evidence that Mediator is essential for Pol II transcription, but is not a required component of the preinitiation complex in vivo

PubMed Central

Petrenko, Natalia; Jin, Yi; Wong, Koon Ho; Struhl, Kevin

2017-01-01

The Mediator complex has been described as a general transcription factor, but it is unclear if it is essential for Pol II transcription and/or is a required component of the preinitiation complex (PIC) in vivo. Here, we show that depletion of individual subunits, even those essential for cell growth, causes a general but only modest decrease in transcription. In contrast, simultaneous depletion of all Mediator modules causes a drastic decrease in transcription. Depletion of head or middle subunits, but not tail subunits, causes a downstream shift in the Pol II occupancy profile, suggesting that Mediator at the core promoter inhibits promoter escape. Interestingly, a functional PIC and Pol II transcription can occur when Mediator is not detected at core promoters. These results provide strong evidence that Mediator is essential for Pol II transcription and stimulates PIC formation, but it is not a required component of the PIC in vivo. DOI: http://dx.doi.org/10.7554/eLife.28447.001 PMID:28699889

Intelligent Articulated Robot

NASA Astrophysics Data System (ADS)

Nyein, Aung Kyaw; Thu, Theint Theint

2008-10-01

In this paper, an articulated type of industrial used robot is discussed. The robot is mainly intended to be used in pick and place operation. It will sense the object at the specified place and move it to a desired location. A peripheral interface controller (PIC16F84A) is used as the main controller of the robot. Infrared LED and IR receiver unit for object detection and 4-bit bidirectional universal shift registers (74LS194) and high current and high voltage Darlington transistors arrays (ULN2003) for driving the arms' motors are used in this robot. The amount of rotation for each arm is regulated by the limit switches. The operation of the robot is very simple but it has the ability of to overcome resetting position after power failure. It can continue its work from the last position before the power is failed without needing to come back to home position.

Capillary trapping of particles in thin-film flows

NASA Astrophysics Data System (ADS)

Dressaire, Emilie; Gomez, Michael; Colnet, Benedicte; Sauret, Alban

2017-11-01

When a thin layer of suspension flows over a substrate, some particles remain trapped on the solid surface. When the thickness of the liquid layer is comparable to the particle size, the particles deform the liquid interface, which leads to local interactions. These effects modify the transport of particles and the dynamics of the liquid films. Here, we characterize how capillary interactions affect the transport and deposition of non-Brownian particles moving in thin liquid films and the resulting loss of transported material. We focus on gravitational drainage flows, in which the film thickness becomes comparable to the particle size. Depending on the concentration of particles, we find that the drainage dynamics exhibits behavior that cannot be captured with a continuum model, due to the deposition of particles on the substrate. ANR-16-CE30-0009 & CNRS-PICS-07242 & ACS-PRF 55845-ND9.

Capillary trapping in thin-film flows of particles

NASA Astrophysics Data System (ADS)

Sauret, Alban; Gomez, Michael; Dressaire, Emilie

Flows of suspensions have been modeled on a continuum level by using constitutive relations to capture how the viscosity varies with the particle concentration. However, in thin liquid films, where the thickness of the liquid layer is comparable to the particle size, the particles deform the liquid interface, which leads to local interactions. These effects modify the transport of particles and could result in the contamination of the surface and the loss of transported material. Here, we characterize how capillary interactions affect the transport and deposition of non-Brownian particles moving in thin liquid films. We focus on gravitational drainage flows, in which the film thickness becomes comparable to the particle size. Depending on the concentration of particles, we find that the dynamics of the drainage exhibits behavior that cannot be captured with a Newtonian model, due to the deposition of particles on the substrate. ANR-16-CE30-0009 and CNRS-PICS-07242.

The Utility of the WHO ICD-10-AM Pastoral Intervention Codings Within Religious, Pastoral and Spiritual Care Research.

PubMed

Carey, Lindsay B; Cohen, Jeffrey

2015-10-01

The World Health Organization (WHO) 'Pastoral Intervention Codings' were first released in 2002 as part of the 'International Statistical Classification of Diseases and Related Health Problems' (WHO 2002). The purpose of the WHO pastoral intervention codings (colloquially abbreviated as 'WHO-PICs') was to record and account for the religious, pastoral and/or spiritual interventions of chaplains and volunteers providing care to patients and other clients experiencing religious and/or spiritual health and well-being issues. The intent of such WHO codings was to provide information in five areas: statistical, research, clinical, education and policy. The purpose of this paper predominantly accounts for research although it does intersect and relate to other WHO priorities. Over the past 10 years, research by the current and associated authors to test the efficacy of the WHO-PICs has been implemented in a number of different health and welfare contexts that have engaged chaplaincy personnel. In summary, while the WHO-PICs are yet to be more widely utilized internationally, the codings have largely proven to be valuable indices appropriate to a variety of contexts. Research utilizing the WHO-PICs, however, has also revealed the necessity for a number of changes and inclusions to be implemented. Recommendations concerning the future utilisation of the WHO-PICs are made, as are recommendations for these codings to be further developed and promoted by the WHO, so as to more accurately record religious, pastoral and spiritual interventions.

Green Tea Catechin-Based Complex Micelles Combined with Doxorubicin to Overcome Cardiotoxicity and Multidrug Resistance

PubMed Central

Cheng, Tangjian; Liu, Jinjian; Ren, Jie; Huang, Fan; Ou, Hanlin; Ding, Yuxun; Zhang, Yumin; Ma, Rujiang; An, Yingli; Liu, Jianfeng; Shi, Linqi

2016-01-01

Chemotherapy for cancer treatment has been demonstrated to cause some side effects on healthy tissues and multidrug resistance of the tumor cells, which greatly limits therapeutic efficacy. To address these limitations and achieve better therapeutic efficacy, combination therapy based on nanoparticle platforms provides a promising approach through delivering different agents simultaneously to the same destination with synergistic effect. In this study, a novel green tea catechin-based polyion complex (PIC) micelle loaded with doxorubicin (DOX) and (-)-Epigallocatechin-3-O-gallate (EGCG) was constructed through electrostatic interaction and phenylboronic acid-catechol interaction between poly(ethylene glycol)-block-poly(lysine-co-lysine-phenylboronic acid) (PEG-PLys/PBA) and EGCG. DOX was co-loaded in the PIC micelles through π-π stacking interaction with EGCG. The phenylboronic acid-catechol interaction endowed the PIC micelles with high stability under physiological condition. Moreover, acid cleavability of phenylboronic acid-catechol interaction in the micelle core has significant benefits for delivering EGCG and DOX to same destination with synergistic effects. In addition, benefiting from the oxygen free radicals scavenging activity of EGCG, combination therapy with EGCG and DOX in the micelle core could protect the cardiomyocytes from DOX-mediated cardiotoxicity according to the histopathologic analysis of hearts. Attributed to modulation of EGCG on P-glycoprotein (P-gp) activity, this kind of PIC micelles could effectively reverse multidrug resistance of cancer cells. These results suggested that EGCG based PIC micelles could effectively overcome DOX induced cardiotoxicity and multidrug resistance. PMID:27375779

Spectral domain, common path OCT in a handheld PIC based system

NASA Astrophysics Data System (ADS)

Leinse, Arne; Wevers, Lennart; Marchenko, Denys; Dekker, Ronald; Heideman, René G.; Ruis, Roosje M.; Faber, Dirk J.; van Leeuwen, Ton G.; Kim, Keun Bae; Kim, Kyungmin

2018-02-01

Optical Coherence Tomography (OCT) has made it into the clinic in the last decade with systems based on bulk optical components. The next disruptive step will be the introduction of handheld OCT systems. Photonic Integrated Circuit (PIC) technology is the key enabler for this further miniaturization. PIC technology allows signal processing on a stable platform and the implementation of a common path interferometer in that same platform creates a robust fully integrated OCT system with a flexible fiber probe. In this work the first PIC based handheld and integrated common path based spectral domain OCT system is described and demonstrated. The spectrometer in the system is based on an Arrayed Waveguide Grating (AWG) and fully integrated with the CCD and a fiber probe into a system operating at 850 nm. The AWG on the PIC creates a 512 channel spectrometer with a resolution of 0.22 nm enabling a high speed analysis of the full A-scan. The silicon nitride based proprietary waveguide technology (TriPleXTM) enables low loss complex photonic structures from the visible (405 nm) to IR (2350 nm) range, making it a unique candidate for OCT applications. Broadband AWG operation from visible to 1700 nm has been shown in the platform and Photonic Design Kits (PDK) are available enabling custom made designs in a system level design environment. This allows a low threshold entry for designing new (OCT) designs for a broad wavelength range.

Green Tea Catechin-Based Complex Micelles Combined with Doxorubicin to Overcome Cardiotoxicity and Multidrug Resistance.

PubMed

Cheng, Tangjian; Liu, Jinjian; Ren, Jie; Huang, Fan; Ou, Hanlin; Ding, Yuxun; Zhang, Yumin; Ma, Rujiang; An, Yingli; Liu, Jianfeng; Shi, Linqi

2016-01-01

Chemotherapy for cancer treatment has been demonstrated to cause some side effects on healthy tissues and multidrug resistance of the tumor cells, which greatly limits therapeutic efficacy. To address these limitations and achieve better therapeutic efficacy, combination therapy based on nanoparticle platforms provides a promising approach through delivering different agents simultaneously to the same destination with synergistic effect. In this study, a novel green tea catechin-based polyion complex (PIC) micelle loaded with doxorubicin (DOX) and (-)-Epigallocatechin-3-O-gallate (EGCG) was constructed through electrostatic interaction and phenylboronic acid-catechol interaction between poly(ethylene glycol)-block-poly(lysine-co-lysine-phenylboronic acid) (PEG-PLys/PBA) and EGCG. DOX was co-loaded in the PIC micelles through π-π stacking interaction with EGCG. The phenylboronic acid-catechol interaction endowed the PIC micelles with high stability under physiological condition. Moreover, acid cleavability of phenylboronic acid-catechol interaction in the micelle core has significant benefits for delivering EGCG and DOX to same destination with synergistic effects. In addition, benefiting from the oxygen free radicals scavenging activity of EGCG, combination therapy with EGCG and DOX in the micelle core could protect the cardiomyocytes from DOX-mediated cardiotoxicity according to the histopathologic analysis of hearts. Attributed to modulation of EGCG on P-glycoprotein (P-gp) activity, this kind of PIC micelles could effectively reverse multidrug resistance of cancer cells. These results suggested that EGCG based PIC micelles could effectively overcome DOX induced cardiotoxicity and multidrug resistance.

Training order and structural location of meaningful stimuli: effects on equivalence class formation.

PubMed

Nartey, Richard K; Arntzen, Erik; Fields, Lanny

2015-12-01

In the present study, equivalence class formation was influenced by the temporal point of inclusion of a meaningful stimulus when baseline relations were serially or sequentially trained, and much less so by the location of the meaningful stimulus in the nodal structure of the class. In Experiment 1, participants attempted to form three 3-node, 5-member classes (A→B→C→D→E) under the simultaneous protocol. After serially training the baseline relations AB, BC, CD, and DE, in that order, the emergence of all emergent relations was tested concurrently. In the A-as-PIC condition, A was meaningful stimulus and B to E were meaningless stimulus, and 60 % of the participants formed classes. In addition, classes were formed by 40 %, 70 %, 40 %, and 20 % of the participants in the B-as-PIC, C-as-PIC, D-as-PIC, and E-as-PIC groups, respectively. Thus, the likelihood of class formation could have been influenced by the location of a meaningful stimulus in the class structure and/or by its order of introduction during training. In Experiment 2, we controlled for any effect of order of introduction by the concurrent training of all of the baseline relations. Regardless of the location of the meaningful stimulus, 0-20 % of participants formed classes. Thus, the temporal order of introducing a meaningful stimulus was the primary modulator of the class-enhancing property of meaningful stimuli, and not the location of the meaningful stimulus in the class structure.

Hybrid integration of laser source on silicon photonic integrated circuit for low-cost interferometry medical device

NASA Astrophysics Data System (ADS)

Duperron, Matthieu; Carroll, Lee; Rensing, Marc; Collins, Sean; Zhao, Yan; Li, Yanlu; Baets, Roel; O'Brien, Peter

2017-02-01

The cost-effective integration of laser sources on Silicon Photonic Integrated Circuits (Si-PICs) is a key challenge to realizing the full potential of on-chip photonic solutions for telecommunication and medical applications. Hybrid integration can offer a route to high-yield solutions, using only known-good laser-chips, and simple freespace micro-optics to transport light from a discrete laser-diode to a grating-coupler on the Si-PIC. In this work, we describe a passively assembled micro-optical bench (MOB) for the hybrid integration of a 1550nm 20MHz linewidth laser-diode on a Si-PIC, developed for an on-chip interferometer based medical device. A dual-lens MOB design minimizes aberrations in the laser spot transported to the standard grating-coupler (15 μm x 12 μm) on the Si-PIC, and facilitates the inclusion of a sub-millimeter latched-garnet optical-isolator. The 20dB suppression from the isolator helps ensure the high-frequency stability of the laser-diode, while the high thermal conductivity of the AlN submount (300/W=m.°C), and the close integration of a micro-bead thermistor, ensure the stable and efficient thermo-electric cooling of the laser-diode, which helps minimise low-frequency drift during the approximately 15s of operation needed for the point-of-care measurement. The dual-lens MOB is compatible with cost-effective passively-aligned mass-production, and can be optimised for alternative PIC-based applications.

VizieR Online Data Catalog: A dust model for bet Pic from 0.58 to 870um (Ballering+, 2016)

NASA Astrophysics Data System (ADS)

Ballering, N. P.; Su, K. Y. L.; Rieke, G. H.; Gaspar, A.

2016-08-01

β Pic was imaged with the HST/STIS CCD in coronagraphic (50CORON) mode under program GO-12551 (PI: Apai), and the results of these observations were published in Apai et al. (2015ApJ...800..136A). The instrument bandpass is set by the response of the CCD and centered at 0.58um. We searched the HST archive and found previously unpublished observations of β Pic with the WFC3 instrument in the IR channel (filter F110W at ~1.16um) from program GO-11150 (PI: Graham). The Spitzer/MIPS observations of β Pic were taken under the Spitzer Guaranteed Time Observing Program 90 (PI: M. Werner). The data at all three bands (24, 70, and 160um) are published here for the first time. Two sets of 24um observations were obtained. The first set was obtained on 2004 March 20, the second set of data was obtained on 2004 April 11. Two sets of 70um observations were obtained. The first set was obtained on 2004 April 12. The second set was obtained on 2005 April 4. Herschel/PACS 70um scan map observations of β Pic (PI G. Olofsson, observation IDs 1342186612 and 1342186613) were published by Vandenbussche et al. (2010A&A...518L.133V). We used the ALMA 870um continuum image previously published by Dent et al. (2014Sci...343.1490D). (1 data file).

A detailed investigation of light-harvesting efficiency of blue color emitting divergent iridium dendrimers with peripheral phenylcarbazole units.

PubMed

Cho, Yang-Jin; Wee, Kyung-Ryang; Son, Ho-Jin; Cho, Dae Won; Kang, Sang Ook

2014-03-14

The increase in phosphorescence efficiency was estimated by the energy transfer mechanism for divergent iridium dendrimers with peripheral phenylcarbazole units. A series of Ir-core/phenylcarbazole-end dendrons of the type, Ir(dfppy)2(pic-Czn) (Gn, n = 0, 1, 2, and 3), was synthesized, where dfppy, pic, and Czn (n = 2, 4, and 8) are 2-(4,6-difluorophenyl)pyridine, picolinate substituted with Czn at the 3-position, and 4-(9-carbazolyl)phenyldendrons connected with 3,5-di(methyleneoxy)benzyloxy branches, respectively. Selective excitation of the Czn units of G1–G3 resulted in >90% quenching of the Cz fluorescence accompanied by the growth of phosphorescence from the Ir(dfppy)2(pic) core as a consequence of energy transfer from the excited-singlet Czn chromophore to the core. The rate constants of energy transfer were determined by steady-state and transient spectroscopic measurements to be 4.32 × 10(9) s(−1) (G1), 2.37 × 10(9) s(−1) (G2), and 1.46 × 10(9) s(−1) (G3), which were in good agreement with those calculated using the Förster model. The phosphorescence enhancements were 157 (G1), 213 (G2), and 264% (G3) when compared to the phosphorescence of the core Ir(dfppy)2(pic-Ph2) (G0), in which pic-Ph2 is 3-(3,5-dibenzyloxybenzyl)picolinate.

Electron-beam-ion-source (EBIS) modeling progress at FAR-TECH, Inc

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

Kim, J. S., E-mail: kim@far-tech.com; Zhao, L., E-mail: kim@far-tech.com; Spencer, J. A., E-mail: kim@far-tech.com

FAR-TECH, Inc. has been developing a numerical modeling tool for Electron-Beam-Ion-Sources (EBISs). The tool consists of two codes. One is the Particle-Beam-Gun-Simulation (PBGUNS) code to simulate a steady state electron beam and the other is the EBIS-Particle-In-Cell (EBIS-PIC) code to simulate ion charge breeding with the electron beam. PBGUNS, a 2D (r,z) electron gun and ion source simulation code, has been extended for efficient modeling of EBISs and the work was presented previously. EBIS-PIC is a space charge self-consistent PIC code and is written to simulate charge breeding in an axisymmetric 2D (r,z) device allowing for full three-dimensional ion dynamics.more » This 2D code has been successfully benchmarked with Test-EBIS measurements at Brookhaven National Laboratory. For long timescale (< tens of ms) ion charge breeding, the 2D EBIS-PIC simulations take a long computational time making the simulation less practical. Most of the EBIS charge breeding, however, may be modeled in 1D (r) as the axial dependence of the ion dynamics may be ignored in the trap. Where 1D approximations are valid, simulations of charge breeding in an EBIS over long time scales become possible, using EBIS-PIC together with PBGUNS. Initial 1D results are presented. The significance of the magnetic field to ion dynamics, ion cooling effects due to collisions with neutral gas, and the role of Coulomb collisions are presented.« less

Observation of 1-D time dependent non-propagating laser plasma structures using fluid and PIC codes

NASA Astrophysics Data System (ADS)

Verma, Deepa; Bera, Ratan Kumar; Kumar, Atul; Patel, Bhavesh; Das, Amita

2017-12-01

The manuscript reports the observation of time dependent localized and non-propagating structures in the coupled laser plasma system through 1-D fluid and Particle-In-Cell (PIC) simulations. It is reported that such structures form spontaneously as a result of collision amongst certain exact solitonic solutions. They are seen to survive as coherent entities for a long time up to several hundreds of plasma periods. Furthermore, it is shown that such time dependence can also be artificially recreated by significantly disturbing the delicate balance between the radiation and the density fields required for the exact non-propagating solution obtained by Esirkepov et al., JETP 68(1), 36-41 (1998). The ensuing time evolution is an interesting interplay between kinetic and field energies of the system. The electrostatic plasma oscillations are coupled with oscillations in the electromagnetic field. The inhomogeneity of the background and the relativistic nature, however, invariably produces large amplitude density perturbations leading to its wave breaking. In the fluid simulations, the signature of wave breaking can be discerned by a drop in the total energy which evidently gets lost to the grid. The PIC simulations are observed to closely follow the fluid simulations till the point of wave breaking. However, the total energy in the case of PIC simulations is seen to remain conserved throughout the simulations. At the wave breaking, the particles are observed to acquire thermal kinetic energy in the case of PIC. Interestingly, even after wave breaking, compact coherent structures with trapped radiation inside high-density peaks continue to exist both in PIC and fluid simulations. Although the time evolution does not exactly match in the two simulations as it does prior to the process of wave breaking, the time-dependent features exhibited by the remnant structures are characteristically similar.

The Gag Cleavage Product, p12, is a Functional Constituent of the Murine Leukemia Virus Pre-Integration Complex

PubMed Central

Laham-Karam, Nihay; Selig, Sara; Ehrlich, Marcelo; Bacharach, Eran

2010-01-01

The p12 protein is a cleavage product of the Gag precursor of the murine leukemia virus (MLV). Specific mutations in p12 have been described that affect early stages of infection, rendering the virus replication-defective. Such mutants showed normal generation of genomic DNA but no formation of circular forms, which are markers of nuclear entry by the viral DNA. This suggested that p12 may function in early stages of infection but the precise mechanism of p12 action is not known. To address the function and follow the intracellular localization of the wt p12 protein, we generated tagged p12 proteins in the context of a replication-competent virus, which allowed for the detection of p12 at early stages of infection by immunofluorescence. p12 was found to be distributed to discrete puncta, indicative of macromolecular complexes. These complexes were localized to the cytoplasm early after infection, and thereafter accumulated adjacent to mitotic chromosomes. This chromosomal accumulation was impaired for p12 proteins with a mutation that rendered the virus integration-defective. Immunofluorescence demonstrated that intracellular p12 complexes co-localized with capsid, a known constituent of the MLV pre-integration complex (PIC), and immunofluorescence combined with fluorescent in situ hybridization (FISH) revealed co-localization of the p12 proteins with the incoming reverse transcribed viral DNA. Interactions of p12 with the capsid and with the viral DNA were also demonstrated by co-immunoprecipitation. These results imply that p12 proteins are components of the MLV PIC. Furthermore, a large excess of wt PICs did not rescue the defect in integration of PICs derived from mutant p12 particles, demonstrating that p12 exerts its function as part of this complex. Altogether, these results imply that p12 proteins are constituent of the MLV PIC and function in directing the PIC from the cytoplasm towards integration. PMID:21085616

Restoration of Akt activity by the bisperoxovanadium compound bpV(pic) attenuates hippocampal apoptosis in experimental neonatal pneumococcal meningitis

PubMed Central

Sury, Matthias D; Vorlet-Fawer, Lorianne; Agarinis, Claudia; Yousefi, Shida; Grandgirard, Denis; Leib, Stephen L; Christen, Stephan

2010-01-01

Pneumococcal meningitis causes apoptosis of developing neurons in the dentate gyrus of the hippocampus. The death of these cells is accompanied with long-term learning and memory deficits in meningitis survivors. Here, we studied the role of the PI3K/Akt (protein kinase B) survival pathway in hippocampal apoptosis in a well-characterized infant rat model of pneumococcal meningitis. Meningitis was accompanied by a significant decrease of the PI3K product phosphatidylinositol 3,4,5-triphosphate (PIP3) and of phosphorylated (i.e., activated) Akt in the hippocampus. At the cellular level, phosphorylated Akt was decreased in both the granular layer and the subgranular zone of the dentate gyrus, the region where the developing neurons undergo apoptosis. Protein levels and activity of PTEN, the major antagonist of PI3K, were unaltered by infection, suggesting that the observed decrease in PIP3 and Akt phosphorylation is a result of decreased PI3K signaling. Treatment with the PTEN inhibitor bpV(pic) restored Akt activity and significantly attenuated hippocampal apoptosis. Co-treatment with the specific PI3K inhibitor LY294002 reversed restoration of Akt activity and attenuation of hippocampal apoptosis, while it had no significant effect on these parameters on its own. These results indicate that the inhibitory effect of bpV(pic) on apoptosis was mediated by PI3K-dependent activation of Akt, strongly suggesting that bpV(pic) acted on PTEN. Treatment with bpV(pic) also partially inhibited the concentration of bacteria and cytokines in the CSF, but this effect was not reversed by LY294002, indicating that the effect of bpV(pic) on apoptosis was independent of its effect on CSF bacterial burden and cytokine levels. These results indicate that the PI3K/Akt pathway plays an important role in the death and survival of developing hippocampal neurons during the acute phase of pneumococcal meningitis. PMID:20875857

ACTIVATION OF COMMON ANTIVIRAL PATHWAYS CAN POTENTIATE INFLAMMATORY RESPONSES TO SEPTIC SHOCK

PubMed Central

Doughty, Lesley A.; Carlton, Stacey; Galen, Benjamin; Cooma-Ramberan, Indranie; Chung, Chung-Shiang; Ayala, Alfred

2006-01-01

Induction of the antiviral cytokine interferon α/β (IFN-α/β) is common in many viral infections. The impact of ongoing antiviral responses on subsequent bacterial infection is not well understood. In human disease, bacterial superinfection complicating a viral infection can result in significant morbidity and mortality. We injected mice with polyinosinic-polycytidylic (PIC) acid, a TLR3 ligand and known IFN-α/β inducer as well as nuclear factor κB (NF-κB) activator to simulate very early antiviral pathways. We then challenged mice with an in vivo septic shock model characterized by slowly evolving bacterial infection to simulate bacterial superinfection early during a viral infection. Our data demonstrated robust induction of IFN-α in serum within 24 h of PIC injection with IFN-α/β–dependent major histocompatibility antigen class II up-regulation on peritoneal macrophages. PIC pretreatment before septic shock resulted in augmented tumor necrosis factor alpha and interleukins 6 and 10 and heightened lethality compared with septic shock alone. Intact IFN-α/β signaling was necessary for augmentation of the inflammatory response to in vivo septic shock and to both TLR2 and TLR4 agonists in vitro. To assess the NF-κB contribution to PIC-modulated inflammatory responses to septic shock, we treated with parthenolide an NF-κB inhibitor before PIC and septic shock. Parthenolide did not inhibit IFN-α induction by PIC. Inhibition of NF-κB by parthenolide did reduce IFN-α–mediated potentiation of the cytokine response and lethality from septic shock. Our data demonstrate that pathways activated early during many viral infections can have a detrimental impact on the outcome of subsequent bacterial infection. These pathways may be critical to understanding the heightened morbidity and mortality from bacterial superinfection after viral infection in human disease. PMID:16878028

Tissue accumulation and urinary excretion of chromium in rats fed diets containing graded levels of chromium chloride or chromium picolinate.

PubMed

Yoshida, Munehiro; Hatakeyama, Erika; Hosomi, Ryota; Kanda, Seiji; Nishiyama, Toshimasa; Fukunaga, Kenji

2010-08-01

To attempt a risk assessment of the excess intake of trivalent chromium (Cr), tissue Cr accumulation and urinary Cr excretion were examined in weanling rats fed experimental diets containing graded levels of Cr chloride (CrCl3) or Cr picolinate (CrPic). Thirty-six male weanling 4-weeks-old Wistar rats were divided into six groups and fed a casein-based semi-purified diet (Cr content: <0.02 microg/g) supplemented with 1, 10, or 100 microg Cr/g as CrCl3 or CrPic for 28 days. Among the experimental groups, no significant difference was observed in body weight; however, supplementation of 100 microg Cr/g to the diets caused a significant low liver weight irrespective of the chemical species of Cr. Activities of serum aspartate aminotransferase and alanine aminotransferase were significantly elevated in rats given CrPic at 100 microg Cr/g. In the liver, kidney and femur, Cr accumulation increased with elevation of the dietary Cr level. No influence of the difference in the chemical species of supplemented Cr was observed in the liver and kidney, but CrCl3 caused significantly higher Cr accumulation than CrPic in the femur of rats given 100 microg Cr/g. Daily urinary Cr excretion elevated with the increase of the dietary Cr level. Rats given CrPic showed significantly higher daily urinary Cr excretion than those given CrCl3, particularly at a dietary Cr level of 100 microg/g. The rate of urinary Cr excretion in rats given CrPic was constant, irrespective of the dietary Cr level, but that of rats given CrCl3 fell with the increase of the dietary Cr level. These results indicate that the lowest adverse effect level of dietary Cr is less than 100 microg/g, irrespective of the chemical species of Cr.

Insulin and chromium picolinate induce translocation of CD36 to the plasma membrane through different signaling pathways in 3T3-L1 adipocytes, and with a differential functionality of the CD36.

PubMed

Wang, Yiqun; Van Oort, Masja M; Yao, Minghui; Van der Horst, Dick J; Rodenburg, Kees W

2011-09-01

Chromium picolinate (CrPic) has been indicated to activate glucose transporter 4 (GLUT4) trafficking to the plasma membrane (PM) to enhance glucose uptake in 3T3-L1 adipocytes. In skeletal and heart muscle cells, insulin directs the intracellular trafficking of the fatty acid translocase/CD36 to induce the uptake of cellular long-chain fatty acid (LCFA). The current study describes the effects of CrPic and insulin on the translocation of CD36 from intracellular storage pools to the PM in 3T3-L1 adipocytes in comparison with that of GLUT4. Immunofluorescence microscopy and immunoblotting revealed that both CD36 and GLUT4 were expressed and primarily located intracellularly in 3T3-L1 adipocytes. Upon insulin or CrPic stimulation, PM expression of CD36 increased in a similar manner as that for GLUT4; the CrPic-stimulated PM expression was less strong than that of insulin. The increase in PM localization for these two proteins by insulin paralleled LCFA ([1-(14)C]palmitate) or [(3)H]deoxyglucose uptake in 3T3-L1 adipocytes. The induction of the PM expression of GLUT4, but not CD36, or substrate uptake by insulin and CrPic appears to be additive in adipocytes. Furthermore, wortmannin completely inhibited the insulin-stimulated translocation of GLUT4 or CD36 and prevented the increased uptake of glucose or LCFA in these cells. Taken together, for the first time, these findings suggest that both insulin and CrPic induce CD36 translocation to the PM in 3T3-L1 adipocytes and that their translocation-inducing effects are not additive. The signaling pathway inducing the translocations is different, apparently resulting in a differential activity of CD36.

Decision-making in multiple sclerosis consultations in Italy: third observer and patient assessments.

PubMed

Pietrolongo, Erika; Giordano, Andrea; Kleinefeld, Monica; Confalonieri, Paolo; Lugaresi, Alessandra; Tortorella, Carla; Pugliatti, Maura; Radice, Davide; Goss, Claudia; Heesen, Christoph; Solari, Alessandra

2013-01-01

To assess decision-making in multiple sclerosis (MS) from third observer and patient perspectives. Audio recordings of first-ever consultations with a participating physician (88 outpatients, 10 physicians) at four tertiary MS care clinics in Italy, were rated by a third observer using the Observing Patient Involvement in Shared Decision Making (OPTION) and by patients using the Perceived Involvement in Care Scale (PICS). Mean patient age was 37.5, 66% were women, 72% had MS, and 28% had possible MS or other disease. Mean PICS subscale scores (range 0 poor, 100 best possible) were 71.9 (SD 24.3) for "physician facilitation" (PICS-F); 74.6 (SD 22.9) for "patient information exchange" (PICS-I); and only 22.5 (SD 16.2) for "patient decision making" (PICS-DM). Mean OPTION total score (0 poor, 100 best possible) was 29.6 (SD 10.3). Poorest OPTION scores were found for items assessing "preferred patient approach to receiving information" and "preferred patient level of involvement." Highest scores were for "clinician drawing attention to identified problem", "indicating need for decision making," and "need to review the decision." Consultation time, woman physician, patient-physician gender concordance and PICS-F were associated with higher OPTION total score; older physician and second opinion consultation were associated with lower OPTION score. In line with findings in other settings, our third observer findings indicated limited patient involvement abilities of MS physicians during first consultations. Patient perceptions of physician skills were better than third observers', although they correlated. Consultations with women physicians, and younger physicians, were associated with higher third observer and patient-based scores. Our findings reveal a need to empower Italian MS physicians with better communication and shared decision-making skills, and show in particular that attention to MS patient preferences for reception of information and involvement in health decisions, need to be improved.

Activation properties of trigeminal motoneurons in participants with and without bruxism

PubMed Central

D'Amico, Jessica M.; Yavuz, Ş. Utku; Saraçoğlu, Ahmet; Atiş, Elif Sibel; Türker, Kemal S.

2013-01-01

In animals, sodium- and calcium-mediated persistent inward currents (PICs), which produce long-lasting periods of depolarization under conditions of low synaptic drive, can be activated in trigeminal motoneurons following the application of the monoamine serotonin. Here we examined if PICs are activated in human trigeminal motoneurons during voluntary contractions and under physiological levels of monoaminergic drive (e.g., serotonin and norepinephrine) using a paired motor unit analysis technique. We also examined if PICs activated during voluntary contractions are larger in participants who demonstrate involuntary chewing during sleep (bruxism), which is accompanied by periods of high monoaminergic drive. In control participants, during a slowly increasing and then decreasing isometric contraction, the firing rate of an earlier-recruited masseter motor unit, which served as a measure of synaptic input to a later-recruited test unit, was consistently lower during derecruitment of the test unit compared with at recruitment (ΔF = 4.6 ± 1.5 imp/s). The ΔF, therefore, is a measure of the reduction in synaptic input needed to counteract the depolarization from the PIC to provide an indirect estimate of PIC amplitude. The range of ΔF values measured in the bruxer participants during similar voluntary contractions was the same as in controls, suggesting that abnormally high levels of monoaminergic drive are not continually present in the absence of involuntary motor activity. We also observed a consistent “onion skin effect” during the moderately sized contractions (<20% of maximal), whereby the firing rate of higher threshold motor units discharged at slower rates (by 4–7 imp/s) compared with motor units with relatively lower thresholds. The presence of lower firing rates in the more fatigue-prone, higher threshold trigeminal motoneurons, in addition to the activation of PICs, likely facilitates the activation of the masseter muscle during motor activities such as eating, nonnutritive chewing, clenching, and yawning. PMID:24068753

Provincially and Locally Initiated Curriculum Program Assessment, Final Report.

ERIC Educational Resources Information Center

1999

This report is an independent assessment of the Provincially Initiated Curriculum (PIC) and Locally Initiated Curriculum (LIC) for British Columbia's Centre for Curriculum, Transfer and Technology (C2T2), which manages both PIC and LIC projects. The report makes four recommendations for C2T2's consideration: (1) a renewed emphasis on communication…

EVALUATION OF CURRENTLY AVAILABLE ALTERNATIVES TO METHYL BROMIDE FOR ORNAMENTAL CROP PRODUCTION IN FLORIDA

USDA-ARS?s Scientific Manuscript database

Studies were designed to test the efficacy of the chemical alternatives, Midas™ (iodomethane:chloropicrin (pic) 50:50 [MI 50:50] and 98:2 [MI 98:2], Arysta LifeScience Corp., Cary, NC) and dimethyl disulfide:pic (Paladin™ 79:21 [DMDS], United Phosphorous, Inc., King of Prussia, PA) compared with met...

Validation of the Offending-Related Attitudes Questionnaire of CRIME-PICS II Scale (Chinese)

ERIC Educational Resources Information Center

Chui, Wing Hong; Wu, Joseph; Kwok, Yan Yuen; Liu, Liu

2017-01-01

This study examined the factor structure, reliability, and validity of the first part of the Chinese version of the CRIME-PICS II Scale, a self-administrated instrument assessing offending-related attitudes. Data were collected from three samples: male Hong Kong young offenders, female Mainland Chinese prisoners, and Hong Kong college students.…

Demonstration of free space coherent optical communication using integrated silicon photonic orbital angular momentum devices.

PubMed

Su, Tiehui; Scott, Ryan P; Djordjevic, Stevan S; Fontaine, Nicolas K; Geisler, David J; Cai, Xinran; Yoo, S J B

2012-04-23

We propose and demonstrate silicon photonic integrated circuits (PICs) for free-space spatial-division-multiplexing (SDM) optical transmission with multiplexed orbital angular momentum (OAM) states over a topological charge range of -2 to +2. The silicon PIC fabricated using a CMOS-compatible process exploits tunable-phase arrayed waveguides with vertical grating couplers to achieve space division multiplexing and demultiplexing. The experimental results utilizing two silicon PICs achieve SDM mux/demux bit-error-rate performance for 1‑b/s/Hz, 10-Gb/s binary phase shifted keying (BPSK) data and 2-b/s/Hz, 20-Gb/s quadrature phase shifted keying (QPSK) data for individual and two simultaneous OAM states. © 2012 Optical Society of America

Temporal Evolution of the Plasma Sheath Surrounding Solar Cells in Low Earth Orbit

NASA Technical Reports Server (NTRS)

Willis, Emily M.; Pour, Maria Z. A.

2017-01-01

Initial results from the PIC simulation and the LEM simulation have been presented. The PIC simulation results show that more detailed study is required to refine the ISS solar array current collection model and to understand the development of the current collection in time. The initial results from the LEM demonstrate that is it possible the transients are caused by solar array interaction with the environment, but there are presently too many assumptions in the model to be certain. Continued work on the PIC simulation will provide valuable information on the development of the barrier potential, which will allow refinement the LEM simulation and a better understanding of the causes and effects of the transients.

Understanding Sgr A* with PIC Simulations of Particle Acceleration in Magnetic Reconnection

NASA Astrophysics Data System (ADS)

Ozel, Feryal

2017-09-01

Sgr A* has been the subject of intense observational studies with Chandra. In the proposed work, we will investigate magnetic reconnection and particle acceleration in low-luminosity black hole accretion flows using a combination of GRMHD and particle-in-cell (PIC) simulations. We will use the PIC simulations to understand how particles are accelerated when magnetic energy is dissipated and quantify the resulting electron energy distributions. Incorporating the results of the microphysical studies into the global simulations of Sgr A*, we will investigate the origin of the intense X-ray flares observed with Chandra. We will also study how these processes affect the 1.3 mm image size in preparation for the upcoming simultaneous Chandra and EHT observations of Sgr A*.

Numerical simulation of ion charge breeding in electron beam ion source

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

Zhao, L., E-mail: zhao@far-tech.com; Kim, Jin-Soo

2014-02-15

The Electron Beam Ion Source particle-in-cell code (EBIS-PIC) tracks ions in an EBIS electron beam while updating electric potential self-consistently and atomic processes by the Monte Carlo method. Recent improvements to the code are reported in this paper. The ionization module has been improved by using experimental ionization energies and shell effects. The acceptance of injected ions and the emittance of extracted ion beam are calculated by extending EBIS-PIC to the beam line transport region. An EBIS-PIC simulation is performed for a Cs charge-breeding experiment at BNL. The charge state distribution agrees well with experiments, and additional simulation results ofmore » radial profiles and velocity space distributions of the trapped ions are presented.« less

Low-profile fiber connector for co-packaged optics

NASA Astrophysics Data System (ADS)

Brusberg, Lars; DeJong, Michael; Butler, Douglas L.; Clark, Jeffrey S.; Sutton, Clifford G.

2018-02-01

We developed a small form factor connector that can be assembled on all four sides of a high-data switch package for fiber connectivity. This paper discusses a novel connector approach that has the potential to meet all co-packaging requirements including solder-reflow-compatibility, de-mateability, low insertion loss and state-of-the art FAU attach. The connector was attached to the PIC for performance evaluation. The average insertion loss across all eight fibers of the assembly was 1.77 dB, including the three optical interfaces: (1) MT-to-MT between connector and receptacle, (2) receptacle-to-PLC and (3) PIC-to-FAU. Also included is the propagation loss of the PIC waveguide. Optical return loss was measured to be -55 dB or lower.

Analysis of the beam halo in negative ion sources by using 3D3V PIC code

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

Miyamoto, K., E-mail: kmiyamot@naruto-u.ac.jp; Nishioka, S.; Goto, I.

The physical mechanism of the formation of the negative ion beam halo and the heat loads of the multi-stage acceleration grids are investigated with the 3D PIC (particle in cell) simulation. The following physical mechanism of the beam halo formation is verified: The beam core and the halo consist of the negative ions extracted from the center and the periphery of the meniscus, respectively. This difference of negative ion extraction location results in a geometrical aberration. Furthermore, it is shown that the heat loads on the first acceleration grid and the second acceleration grid are quantitatively improved compared with thosemore » for the 2D PIC simulation result.« less

Adversarial search by evolutionary computation.

PubMed

Hong, T P; Huang, K Y; Lin, W Y

2001-01-01

In this paper, we consider the problem of finding good next moves in two-player games. Traditional search algorithms, such as minimax and alpha-beta pruning, suffer great temporal and spatial expansion when exploring deeply into search trees to find better next moves. The evolution of genetic algorithms with the ability to find global or near global optima in limited time seems promising, but they are inept at finding compound optima, such as the minimax in a game-search tree. We thus propose a new genetic algorithm-based approach that can find a good next move by reserving the board evaluation values of new offspring in a partial game-search tree. Experiments show that solution accuracy and search speed are greatly improved by our algorithm.

Discordant changes in plasma ACTH and beta-lipotropin/beta-endorphin levels in Cushing's disease patients with depression.

PubMed

Starkman, M N; Schteingart, D E; Schork, M A

1992-11-01

Cushing's Disease is often associated with a depressive syndrome, with mood, vegetative, and cognitive abnormalities of variable severity. In 11 patients with (pituitary ACTH-dependent) Cushing's disease (10 women, 1 man), we studied the relationship between severity of the depressive syndrome and concordance of changes in ACTH and beta-lipotropin/beta-endorphin (beta-LPH/beta-E) levels at baseline and in response to metyrapone and dexamethasone. For each condition, blood samples were drawn at 0800h, 1200h, 1600h, and 2200h. Six patients were categorized as mildly depressed (mean [+/- SD] depressed mood score = 0.17 +/- 0.4; modified Hamilton Depression scale score = 7.6 +/- 4.5) and five as severely depressed (mean depressed mood score = 2.4 +/- 0.5; modified Hamilton Depression scale score = 15 +/- 5.6) (p < 0.05). ACTH and beta-LPH/beta-E were measured by radioimmunoassay. For each experimental condition, changes in levels were scored as concordant if the two peptides moved in parallel between sampling points. There was a relationship between greater severity of depression and more frequent discordant changes in ACTH and beta-LPH/beta-E levels: The six patients with mild depression exhibited 23 concordant and 3 discordant change patterns, while the five patients with severe depression showed 8 concordant and 15 discordant patterns. The mean percentage of concordant patterns per patient differed significantly between the two groups (mildly depressed = 90.0 +/- 16.7; severely depressed = 34.6 +/- 8.7 (p < 0.001). When each study condition was examined separately, differences in the frequency of concordance between the groups reached significance during the post-metyrapone phase and with 8.0 mg dexamethasone administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Quasi-monoenergetic proton beam from a proton-layer embedded metal foil irradiated by an intense laser pulse

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

Kim, Kyung Nam; Lee, Kitae, E-mail: klee@kaeri.re.kr; Kumar, Manoj

A target structure, ion-layer embedded foil (ILEF) is proposed for producing a quasi-monoenergetic proton beam by utilizing a bulk electrostatic field, which is generated by irradiating the target with an ultra-intense laser pulse, inside the plasma. Compared with the case of a single metal foil in which the proton layer is initially present on the surface, in the ILEF target, the proton layer is initially located inside a metal foil. A two-dimensional particle-in-cell (PIC) simulation shows that the target generates a proton beam with a narrow energy spread. With a laser intensity of 2 × 10{sup 19 }W/cm{sup 2}, a 22-MeV proton beammore » with an energy spread of 8% at the full-width-half-maximum (FWHM) is obtained when the proton layer is located at 0.4 μm inside the rear surface of a 2.4 μm-thick copper foil. When the proton layer moves toward the front side, a proton beam with a flat-top energy distribution ranging from 15 MeV to 35 MeV is obtained. Further, with a higher laser intensity of 10{sup 21 }W/cm{sup 2}, a proton beam with the maximum energy of 345 MeV and FWHM energy spread of 7.2% is obtained. The analysis of the PIC simulation with an aid of a fluid analysis shows that the spectrum is affected by the initial position of the proton layer, its initial spread during the formation of the sheath field, and the space charge effect.« less

Impact of storage environment on the efficacy of hermetic storage bags.

PubMed

Lane, Brett; Woloshuk, Charles

2017-05-01

Small hermetic bags (50 and 100 kg capacities) used by smallholder farmers in several African countries have proven to be a low-cost solution for preventing storage losses due to insects. The complexity of postharvest practices and the need for ideal drying conditions, especially in the Sub-Sahara, has led to questions about the efficacy of the hermetic bags for controlling spoilage by fungi and the potential for mycotoxin accumulation. This study compared the effects of environmental temperature and relative humidity at two locations (Indiana and Arkansas) on dry maize (14% moisture content) in woven polypropylene bags and Purdue Improved Crop Storage (PICS) hermetic bags. Temperature and relative humidity data loggers placed in the middle of each bag provided profiles of environmental influences on stored grain at the two locations. The results indicated that the PICS bags prevented moisture penetration over the three-month storage period. In contrast, maize in the woven bags increased in moisture content. For both bag types, no evidence was obtained indicating the spread of Aspergillus flavus from colonized maize to adjacent non-colonized maize. However, other storage fungi did increase during storage. The number of infected kernels did not increase in the PICS bags, but the numbers in the woven bags increased significantly. The warmer environment in Arkansas resulted in significantly higher insect populations in the woven bags than in Indiana. Insects in the PICS bags remained low at both locations. This study demonstrates that the PICS hermetic bags are effective at blocking the effects of external humidity fluctuations as well as the spread of fungi to non-infected kernels.

Sobre el estado evolutivo de β Pictoris

NASA Astrophysics Data System (ADS)

Brunini, A.; Benvenuto, O. G.

Desde el descubrimiento de fuertes excesos infrarrojos en β Pictoris, esta estrella ha sido muy estudiada y es considerada candidata a poseer un sistema planetario propio. β Pic está rodeada de un disco asimétrico de polvo que se observa de canto y que esta vacío a distancias <= 40 AU. Esto se considera una fuerte evidencia en favor de la presencia de (al menos) un planeta gigante. Recientemente se han observado líneas de material circunestelar que se han interpretado como consecuencia de la caída de objetos cometarios sobre esta estrella. Recientemente se ha utilizado la existencia del disco de polvo para atribuir una edad corta (pre - secuencia principal) a βPic. Sin embargo, la evaporación de estos cometas provee suficiente polvo como para explicar la presencia del disco observado sin necesidad de edades cortas. En este trabajo mostramos que la comparación entre la tasa de impactos cometarios estimada en el Sistema Solar para diferentes etapas de su evolución y los datos observados en β Pic indica edades avanzadas para β Pic. Esta estimación debe tomarse con cautela ya que depende de la estructura de los sistemas planetarios. Además mostramos que, desde el punto de vista de la evolución estelar y con las incertezas presentes en la luminosidad y la temperatura efectiva, existe un continuo de edades posible para β Pic. Sin embargo, empleando los datos provenientes de los flujos cometarios encontramos que una edad prolongada es consistente con ambos tratamientos.

Mutual reinforcement of pathophysiological host-microbe interactions in intestinal stasis models

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

Touw, Ketrija; Ringus, Daina L.; Hubert, Nathaniel

Chronic diseases arise when there is mutual reinforcement of pathophysiological processes that cause an aberrant steady state. Such a sequence of events may underlie chronic constipation, which has been associated with dysbiosis of the gut. In this study we hypothesized that assemblage of microbial communities, directed by slow gastrointestinal transit, affects host function in a way that reinforces constipation and further maintains selection on microbial communities. In our study, we used two models – an opioid-induced consti- pation model in mice, and a humanized mouse model where germ-free mice were colonized with stool from a patient with constipation-predominant irritable bowelmore » syndrome (IBS-C) in humans. We examined the impact of pharmacologically (loperamide)-induced constipation (PIC) and IBS-C on the structural and functional profile of the gut microbiota. Germ-free (GF) mice were colonized with microbiota from PIC donor mice and IBS-C patients to determine how the microbiota affects the host. PIC and IBS-C promoted changes in the gut microbiota, characterized by increased relative abundance of Bacteroides ovatus and Parabacteroides distasonis in both models. PIC mice exhibited decreased luminal concentrations of butyrate in the cecum and altered metabolic profiles of the gut microbiota. Colonization of GF mice with PIC-associated mice cecal or human IBS-C fecal microbiota significantly increased GI transit time when compared to control microbiota recipients. IBS-C-associated gut microbiota also impacted colonic contractile properties. Lastly, our findings support the concept that constipation is characterized by dis- ease-associated steady states caused by reinforcement of pathophysiological factors in host-microbe interactions.« less

Energy release and transfer in guide field reconnection

NASA Astrophysics Data System (ADS)

Birn, J.; Hesse, M.

2010-01-01

Properties of energy release and transfer by magnetic reconnection in the presence of a guide field are investigated on the basis of 2.5-dimensional magnetohydrodynamic (MHD) and particle-in-cell (PIC) simulations. Two initial configurations are considered: a plane current sheet with a uniform guide field of 80% of the reconnecting magnetic field component and a force-free current sheet in which the magnetic field strength is constant but the field direction rotates by 180° through the current sheet. The onset of reconnection is stimulated by localized, temporally limited compression. Both MHD and PIC simulations consistently show that the outgoing energy fluxes are dominated by (redirected) Poynting flux and enthalpy flux, whereas bulk kinetic energy flux and heat flux (in the PIC simulation) are small. The Poynting flux is mainly associated with the magnetic energy of the guide field which is carried from inflow to outflow without much alteration. The conversion of annihilated magnetic energy to enthalpy flux (that is, thermal energy) stems mainly from the fact that the outflow occurs into a closed field region governed by approximate force balance between Lorentz and pressure gradient forces. Therefore, the energy converted from magnetic to kinetic energy by Lorentz force acceleration becomes immediately transferred to thermal energy by the work done by the pressure gradient force. Strong similarities between late stages of MHD and PIC simulations result from the fact that conservation of mass and entropy content and footpoint displacement of magnetic flux tubes, imposed in MHD, are also approximately satisfied in the PIC simulations.

Innate Immunity in the Persistent Inflammation, Immunosuppression, and Catabolism Syndrome and Its Implications for Therapy

PubMed Central

Horiguchi, Hiroyuki; Loftus, Tyler J.; Hawkins, Russell B.; Raymond, Steven L.; Stortz, Julie A.; Hollen, McKenzie K.; Weiss, Brett P.; Miller, Elizabeth S.; Bihorac, Azra; Larson, Shawn D.; Mohr, Alicia M.; Brakenridge, Scott C.; Tsujimoto, Hironori; Ueno, Hideki; Moore, Frederick A.; Moldawer, Lyle L.; Efron, Philip A.

2018-01-01

Clinical and technological advances promoting early hemorrhage control and physiologic resuscitation as well as early diagnosis and optimal treatment of sepsis have significantly decreased in-hospital mortality for many critically ill patient populations. However, a substantial proportion of severe trauma and sepsis survivors will develop protracted organ dysfunction termed chronic critical illness (CCI), defined as ≥14 days requiring intensive care unit (ICU) resources with ongoing organ dysfunction. A subset of CCI patients will develop the persistent inflammation, immunosuppression, and catabolism syndrome (PICS), and these individuals are predisposed to a poor quality of life and indolent death. We propose that CCI and PICS after trauma or sepsis are the result of an inappropriate bone marrow response characterized by the generation of dysfunctional myeloid populations at the expense of lympho- and erythropoiesis. This review describes similarities among CCI/PICS phenotypes in sepsis, cancer, and aging and reviews the role of aberrant myelopoiesis in the pathophysiology of CCI and PICS. In addition, we characterize pathogen recognition, the interface between innate and adaptive immune systems, and therapeutic approaches including immune modulators, gut microbiota support, and nutritional and exercise therapy. Finally, we discuss the future of diagnostic and prognostic approaches guided by machine and deep-learning models trained and validated on big data to identify patients for whom these approaches will yield the greatest benefits. A deeper understanding of the pathophysiology of CCI and PICS and continued investigation into novel therapies harbor the potential to improve the current dismal long-term outcomes for critically ill post-injury and post-infection patients. PMID:29670613

Mutual reinforcement of pathophysiological host-microbe interactions in intestinal stasis models

DOE PAGES

Touw, Ketrija; Ringus, Daina L.; Hubert, Nathaniel; ...

2017-03-20

Chronic diseases arise when there is mutual reinforcement of pathophysiological processes that cause an aberrant steady state. Such a sequence of events may underlie chronic constipation, which has been associated with dysbiosis of the gut. In this study we hypothesized that assemblage of microbial communities, directed by slow gastrointestinal transit, affects host function in a way that reinforces constipation and further maintains selection on microbial communities. In our study, we used two models – an opioid-induced consti- pation model in mice, and a humanized mouse model where germ-free mice were colonized with stool from a patient with constipation-predominant irritable bowelmore » syndrome (IBS-C) in humans. We examined the impact of pharmacologically (loperamide)-induced constipation (PIC) and IBS-C on the structural and functional profile of the gut microbiota. Germ-free (GF) mice were colonized with microbiota from PIC donor mice and IBS-C patients to determine how the microbiota affects the host. PIC and IBS-C promoted changes in the gut microbiota, characterized by increased relative abundance of Bacteroides ovatus and Parabacteroides distasonis in both models. PIC mice exhibited decreased luminal concentrations of butyrate in the cecum and altered metabolic profiles of the gut microbiota. Colonization of GF mice with PIC-associated mice cecal or human IBS-C fecal microbiota significantly increased GI transit time when compared to control microbiota recipients. IBS-C-associated gut microbiota also impacted colonic contractile properties. Lastly, our findings support the concept that constipation is characterized by dis- ease-associated steady states caused by reinforcement of pathophysiological factors in host-microbe interactions.« less

SPIDER: Next Generation Chip Scale Imaging Sensor Update

NASA Astrophysics Data System (ADS)

Duncan, A.; Kendrick, R.; Ogden, C.; Wuchenich, D.; Thurman, S.; Su, T.; Lai, W.; Chun, J.; Li, S.; Liu, G.; Yoo, S. J. B.

2016-09-01

The Lockheed Martin Advanced Technology Center (LM ATC) and the University of California at Davis (UC Davis) are developing an electro-optical (EO) imaging sensor called SPIDER (Segmented Planar Imaging Detector for Electro-optical Reconnaissance) that seeks to provide a 10x to 100x size, weight, and power (SWaP) reduction alternative to the traditional bulky optical telescope and focal-plane detector array. The substantial reductions in SWaP would reduce cost and/or provide higher resolution by enabling a larger-aperture imager in a constrained volume. Our SPIDER imager replaces the traditional optical telescope and digital focal plane detector array with a densely packed interferometer array based on emerging photonic integrated circuit (PIC) technologies that samples the object being imaged in the Fourier domain (i.e., spatial frequency domain), and then reconstructs an image. Our approach replaces the large optics and structures required by a conventional telescope with PICs that are accommodated by standard lithographic fabrication techniques (e.g., complementary metal-oxide-semiconductor (CMOS) fabrication). The standard EO payload integration and test process that involves precision alignment and test of optical components to form a diffraction limited telescope is, therefore, replaced by in-process integration and test as part of the PIC fabrication, which substantially reduces associated schedule and cost. This paper provides an overview of performance data on the second-generation PIC for SPIDER developed under the Defense Advanced Research Projects Agency (DARPA)'s SPIDER Zoom research funding. We also update the design description of the SPIDER Zoom imaging sensor and the second-generation PIC (high- and low resolution versions).

Peroxovanadium compounds: biological actions and mechanism of insulin-mimesis.

PubMed

Bevan, A P; Drake, P G; Yale, J F; Shaver, A; Posner, B I

When used alone, both vanadate and hydrogen peroxide (H2O2) are weakly insulin-mimetic, while in combination they are strongly synergistic due to the formation of aqueous peroxovanadium species pV(aq). Administration of these pV(aq) species leads to activation of the insulin receptor tyrosine kinase (IRK), autophosphorylation at tyrosine residues and inhibition of phosphotyrosine phosphatases (PTPs). We therefore undertook to synthesize a series of peroxovanadium (pV) compounds containing one or two peroxo anions, an oxo anion and an ancillary ligand in the inner co-ordination sphere of vanadium, whose properties and insulin-mimetic potencies could be assessed. These pV compounds were shown to be the most potent inhibitors of PTPs yet described. Their PTP inhibitory potency correlated with their capacity to stimulate IRK activity. Some pV compounds showed much greater potency as inhibitors of insulin receptor (IR) dephosphorylation than epidermal growth factor receptor (EGFR) dephosphorylation, implying relative specificity as PTP inhibitors. Replacement of vanadium with either molybdenum or tungsten resulted in equally potent inhibition of IR dephosphorylation. However IRK activation was reduced by greater than 80% suggesting that these compounds did not access intracellular PTPs. The insulin-like activity of these pV compounds were demonstrable in vivo. Intra venous (i.v.) administration of bpV(pic) and bpV(phen) resulted in the lowering of plasma glucose concentrations in normal rats in a dose dependent manner. The greater potency of bpV(pic) compared to bpV(phen) was explicable, in part, by the capacity of the former but not the latter to act on skeletal muscle as well as liver. Finally administration of bpV(phen) and insulin led to a synergism, where tyrosine phosphorylation of the IR beta-subunit increased by 20-fold and led to the appearance of four insulin-dependent in vivo substrates. The insulin-mimetic properties of the pV compounds raises the possibility for their use as insulin replacements in the management of diabetes mellitus.

Interplay between protons and electrons in a firehose-unstable plasma: Particle-in-cell simulations

NASA Astrophysics Data System (ADS)

Bourdin, Philippe-A.; Maneva, Yana

2017-04-01

Kinetic plasma instabilities originating from unstable, non-Maxwellian shapes of the velocity distribution functions serve as internal degrees of freedom in plasma dynamics, and play an important role near solar current sheets and in solar wind plasmas. In the presence of strong temperature anisotropy (different thermal spreads in the velocity space with respect to the mean magnetic field), plasmas are unstable either to the firehose mode or to the mirror mode in the case of predominant parallel and perpendicular temperatures, respectively. The growth rates of these instabilities and their thresholds depend on plasma properties, such as the temperature anisotropy and the plasma beta. The physics of the temperature anisotropy-driven instabilities becomes even more diverse for various shapes of velocity distribution functions and the particle species of interest. Recent studies based on a linear instability analysis show an interplay in the firehose instability between protons and electrons when the both types of particle species are prone to unstable velocity distribution functions and their instability thresholds. In this work we perform for the first time 3D nonlinear PIC (particle-in-cell) numerical simulations to test for the linear-theory prediction of the simultaneous proton-electron firehose instability. The simulation setup allows us not only to evaluate the growth rate of each firehose instability, but also to track its nonlinear evolution and the related wave-particle interactions such as the pitch-angle scattering or saturation effects. The specialty of our simulation is that the magnetic and electric fields have a low numerical noise level by setting a sufficiently large number of super-particles into the simulation box and enhancing the statistical significance of the velocity distribution functions. We use the iPIC3D code with fully periodic boundaries under various conditions of the electron-to-proton mass ratio, which gives insight into the instability interplay at the intermediate electron-proton and on the scaling of our results towards more realistic particle settings.

The New Business Look in Employment and Training Programs. The Private Sector Initiative Program (PSIP). Second Edition.

ERIC Educational Resources Information Center

Garcia, Uvaldo

Intended to inform local communities (especially the business sector) of ways to join government-sponsored employment and training programs with the private employment market, this handbook provides broad guidelines for use in the establishment and operation of the Private Industry Council (PIC). (The PIC is the primary vehicle created by Title…

Reduced 3d modeling on injection schemes for laser wakefield acceleration at plasma scale lengths

NASA Astrophysics Data System (ADS)

Helm, Anton; Vieira, Jorge; Silva, Luis; Fonseca, Ricardo

2017-10-01

Current modelling techniques for laser wakefield acceleration (LWFA) are based on particle-in-cell (PIC) codes which are computationally demanding. In PIC simulations the laser wavelength λ0, in μm-range, has to be resolved over the acceleration lengths in meter-range. A promising approach is the ponderomotive guiding center solver (PGC) by only considering the laser envelope for laser pulse propagation. Therefore only the plasma skin depth λp has to be resolved, leading to speedups of (λp /λ0) 2. This allows to perform a wide-range of parameter studies and use it for λ0 <<λp studies. We present the 3d version of a PGC solver in the massively parallel, fully relativistic PIC code OSIRIS. Further, a discussion and characterization of the validity of the PGC solver for injection schemes on the plasma scale lengths, such as down-ramp injection, magnetic injection and ionization injection, through parametric studies, full PIC simulations and theoretical scaling, is presented. This work was partially supported by Fundacao para a Ciencia e Tecnologia (FCT), Portugal, through Grant No. PTDC/FIS-PLA/2940/2014 and PD/BD/105882/2014.

AP-Cloud: Adaptive particle-in-cloud method for optimal solutions to Vlasov–Poisson equation

DOE PAGES

Wang, Xingyu; Samulyak, Roman; Jiao, Xiangmin; ...

2016-04-19

We propose a new adaptive Particle-in-Cloud (AP-Cloud) method for obtaining optimal numerical solutions to the Vlasov–Poisson equation. Unlike the traditional particle-in-cell (PIC) method, which is commonly used for solving this problem, the AP-Cloud adaptively selects computational nodes or particles to deliver higher accuracy and efficiency when the particle distribution is highly non-uniform. Unlike other adaptive techniques for PIC, our method balances the errors in PDE discretization and Monte Carlo integration, and discretizes the differential operators using a generalized finite difference (GFD) method based on a weighted least square formulation. As a result, AP-Cloud is independent of the geometric shapes ofmore » computational domains and is free of artificial parameters. Efficient and robust implementation is achieved through an octree data structure with 2:1 balance. We analyze the accuracy and convergence order of AP-Cloud theoretically, and verify the method using an electrostatic problem of a particle beam with halo. Here, simulation results show that the AP-Cloud method is substantially more accurate and faster than the traditional PIC, and it is free of artificial forces that are typical for some adaptive PIC techniques.« less

High-performance modeling of plasma-based acceleration and laser-plasma interactions

NASA Astrophysics Data System (ADS)

Vay, Jean-Luc; Blaclard, Guillaume; Godfrey, Brendan; Kirchen, Manuel; Lee, Patrick; Lehe, Remi; Lobet, Mathieu; Vincenti, Henri

2016-10-01

Large-scale numerical simulations are essential to the design of plasma-based accelerators and laser-plasma interations for ultra-high intensity (UHI) physics. The electromagnetic Particle-In-Cell (PIC) approach is the method of choice for self-consistent simulations, as it is based on first principles, and captures all kinetic effects, and also scale favorably to many cores on supercomputers. The standard PIC algorithm relies on second-order finite-difference discretization of the Maxwell and Newton-Lorentz equations. We present here novel formulations, based on very high-order pseudo-spectral Maxwell solvers, which enable near-total elimination of the numerical Cherenkov instability and increased accuracy over the standard PIC method for standard laboratory frame and Lorentz boosted frame simulations. We also present the latest implementations in the PIC modules Warp-PICSAR and FBPIC on the Intel Xeon Phi and GPU architectures. Examples of applications will be given on the simulation of laser-plasma accelerators and high-harmonic generation with plasma mirrors. Work supported by US-DOE Contracts DE-AC02-05CH11231 and by the European Commission through the Marie Slowdoska-Curie fellowship PICSSAR Grant Number 624543. Used resources of NERSC.

A multi-dimensional, energy- and charge-conserving, nonlinearly implicit, electromagnetic Vlasov–Darwin particle-in-cell algorithm

DOE PAGES

Chen, G.; Chacón, L.

2015-08-11

For decades, the Vlasov–Darwin model has been recognized to be attractive for particle-in-cell (PIC) kinetic plasma simulations in non-radiative electromagnetic regimes, to avoid radiative noise issues and gain computational efficiency. However, the Darwin model results in an elliptic set of field equations that renders conventional explicit time integration unconditionally unstable. We explore a fully implicit PIC algorithm for the Vlasov–Darwin model in multiple dimensions, which overcomes many difficulties of traditional semi-implicit Darwin PIC algorithms. The finite-difference scheme for Darwin field equations and particle equations of motion is space–time-centered, employing particle sub-cycling and orbit-averaging. This algorithm conserves total energy, local charge,more » canonical-momentum in the ignorable direction, and preserves the Coulomb gauge exactly. An asymptotically well-posed fluid preconditioner allows efficient use of large cell sizes, which are determined by accuracy considerations, not stability, and can be orders of magnitude larger than required in a standard explicit electromagnetic PIC simulation. Finally, we demonstrate the accuracy and efficiency properties of the algorithm with various numerical experiments in 2D–3V.« less

On-chip immobilization of planarians for in vivo imaging.

PubMed

Dexter, Joseph P; Tamme, Mary B; Lind, Christine H; Collins, Eva-Maria S

2014-09-17

Planarians are an important model organism for regeneration and stem cell research. A complete understanding of stem cell and regeneration dynamics in these animals requires time-lapse imaging in vivo, which has been difficult to achieve due to a lack of tissue-specific markers and the strong negative phototaxis of planarians. We have developed the Planarian Immobilization Chip (PIC) for rapid, stable immobilization of planarians for in vivo imaging without injury or biochemical alteration. The chip is easy and inexpensive to fabricate, and worms can be mounted for and removed after imaging within minutes. We show that the PIC enables significantly higher-stability immobilization than can be achieved with standard techniques, allowing for imaging of planarians at sub-cellular resolution in vivo using brightfield and fluorescence microscopy. We validate the performance of the PIC by performing time-lapse imaging of planarian wound closure and sequential imaging over days of head regeneration. We further show that the device can be used to immobilize Hydra, another photophobic regenerative model organism. The simple fabrication, low cost, ease of use, and enhanced specimen stability of the PIC should enable its broad application to in vivo studies of stem cell and regeneration dynamics in planarians and Hydra.

On-chip immobilization of planarians for in vivo imaging

PubMed Central

Dexter, Joseph P.; Tamme, Mary B.; Lind, Christine H.; Collins, Eva-Maria S.

2014-01-01

Planarians are an important model organism for regeneration and stem cell research. A complete understanding of stem cell and regeneration dynamics in these animals requires time-lapse imaging in vivo, which has been difficult to achieve due to a lack of tissue-specific markers and the strong negative phototaxis of planarians. We have developed the Planarian Immobilization Chip (PIC) for rapid, stable immobilization of planarians for in vivo imaging without injury or biochemical alteration. The chip is easy and inexpensive to fabricate, and worms can be mounted for and removed after imaging within minutes. We show that the PIC enables significantly higher-stability immobilization than can be achieved with standard techniques, allowing for imaging of planarians at sub-cellular resolution in vivo using brightfield and fluorescence microscopy. We validate the performance of the PIC by performing time-lapse imaging of planarian wound closure and sequential imaging over days of head regeneration. We further show that the device can be used to immobilize Hydra, another photophobic regenerative model organism. The simple fabrication, low cost, ease of use, and enhanced specimen stability of the PIC should enable its broad application to in vivo studies of stem cell and regeneration dynamics in planarians and Hydra. PMID:25227263

Experimental demonstration of interferometric imaging using photonic integrated circuits.

PubMed

Su, Tiehui; Scott, Ryan P; Ogden, Chad; Thurman, Samuel T; Kendrick, Richard L; Duncan, Alan; Yu, Runxiang; Yoo, S J B

2017-05-29

This paper reports design, fabrication, and demonstration of a silica photonic integrated circuit (PIC) capable of conducting interferometric imaging with multiple baselines around λ = 1550 nm. The PIC consists of four sets of five waveguides (total of twenty waveguides), each leading to a three-band spectrometer (total of sixty waveguides), after which a tunable Mach-Zehnder interferometer (MZI) constructs interferograms from each pair of the waveguides. A total of thirty sets of interferograms (ten pairs of three spectral bands) is collected by the detector array at the output of the PIC. The optical path difference (OPD) of each interferometer baseline is kept to within 1 µm to maximize the visibility of the interference measurement. We constructed an experiment to utilize the two baselines for complex visibility measurement on a point source and a variable width slit. We used the point source to demonstrate near unity value of the PIC instrumental visibility, and used the variable slit to demonstrate visibility measurement for a simple extended object. The experimental result demonstrates the visibility of baseline 5 and 20 mm for a slit width of 0 to 500 µm in good agreement with theoretical predictions.

Magnetic Field-Vector Measurements in Quiescent Prominences via the Hanle Effect: Analysis of Prominences Observed at Pic-Du-Midi and at Sacramento Peak

NASA Technical Reports Server (NTRS)

Bommier, V.; Leroy, J. L.; Sahal-Brechot, S.

1985-01-01

The Hanle effect method for magnetic field vector diagnostics has now provided results on the magnetic field strength and direction in quiescent prominences, from linear polarization measurements in the He I E sub 3 line, performed at the Pic-du-Midi and at Sacramento Peak. However, there is an inescapable ambiguity in the field vector determination: each polarization measurement provides two field vector solutions symmetrical with respect to the line-of-sight. A statistical analysis capable of solving this ambiguity was applied to the large sample of prominences observed at the Pic-du-Midi (Leroy, et al., 1984); the same method of analysis applied to the prominences observed at Sacramento Peak (Athay, et al., 1983) provides results in agreement on the most probable magnetic structure of prominences; these results are detailed. The statistical results were confirmed on favorable individual cases: for 15 prominences observed at Pic-du-Midi, the two-field vectors are pointing on the same side of the prominence, and the alpha angles are large enough with respect to the measurements and interpretation inaccuracies, so that the field polarity is derived without any ambiguity.

Hall-MHD and PIC Modeling of the Conduction-to-Opening Transition in a Plasma Opening Switch

NASA Astrophysics Data System (ADS)

Schumer, J. W.; SwanekampDdagger, S. B.; Ottinger, P. F.; Commisso, R. J.; Weber, B. V.

1998-11-01

Utilizing the fast opening characteristics of a plasma opening switch (POS), inductive energy storage devices can generate short-duration high-power pulses (<0.1 μ s, >1 TW) with current rise-times on the order of 10 ns. Plasma redistribution and thinning during the POS conduction phase can be modeled adequately with MHD methods. By including the Hall term in Ohm's Law, MHD methods can simulate plasmas with density gradient scale lengths between c/ω_pe < Ln < c/ω_pi. However, the neglect of electron inertia (c/ω_pe) and space-charge separation (λ_De) by single-fluid theory eventually becomes invalid in small gap regions that form during POS opening. PIC methods are well-suited for low-density plasmas, but are numerically taxed by high-density POS regions. An interface converts MHD (Mach2) output into PIC (Magic) input suitable for validating various transition criteria through comparison of current and density distributions from both methods. We will discuss recent progress in interfacing Hall-MHD and PIC simulations. Work supported by Defense Special Weapons Agency. ^ NRL-NRC Research Associate. hspace0.25in ^ JAYCOR, Vienna, VA 22102.

Landsat-7 ETM+ Radiometric Calibration Status

NASA Technical Reports Server (NTRS)

Barsi, Julia A.; Markham, Brian L.; Czapla-Myers, Jeffrey S.; Helder, Dennis L.; Hook, Simon J.; Schott, John R; Haque, Md. Obaidul

2016-01-01

Now in its 17th year of operation, the Enhanced Thematic Mapper + (ETM+), on board the Landsat-7 satellite, continues to systematically acquire imagery of the Earth to add to the 40+ year archive of Landsat data. Characterization of the ETM+ on-orbit radiometric performance has been on-going since its launch in 1999. The radiometric calibration of the reflective bands is still monitored using on-board calibration devices, though the Pseudo-Invariant Calibration Sites (PICS) method has proven to be an effect tool as well. The calibration gains were updated in April 2013 based primarily on PICS results, which corrected for a change of as much as -0.2%/year degradation in the worst case bands. A new comparison with the SADE database of PICS results indicates no additional degradation in the updated calibration. PICS data are still being tracked though the recent trends are not well understood. The thermal band calibration was updated last in October 2013 based on a continued calibration effort by NASA/Jet Propulsion Lab and Rochester Institute of Technology. The update accounted for a 0.31 W/sq m/ sr/micron bias error. The updated lifetime trend is now stable to within + 0.4K.

Conductor backed and shielded multi-layer coplanar waveguide designs on LTCC for RF carrier boards for packaging PICs

NASA Astrophysics Data System (ADS)

Marraccini, Philip J.; Jezzini, Moises A.; Peters, Frank H.

2016-05-01

Designing photonic integrated circuits (PICs) with packaging in mind is important since this impacts the performance of the final product. In coherent optical communication applications there are a large number of DC and RF lines that need routed to connect the PIC to the outer packaging. These RF lines should be impedance matched to the devices, isolated from each other, low loss and protected against electromagnetic interference (EMI) over the frequency range of interest to achieve the performance required for the application. Multilevel low temperature co-fired ceramic (LTCC) boards can be used as a carrier board connecting the PIC to the packaging due to its good RF performance, machinability, compatibility with hermetic sealing, and ability to integrate drivers into the board. Flexibility with layer numbers enables additional layers for shielding against electromagnetic interference or increased space for routing electrical connections. In this paper the design, simulations, and measured results for a set of 4 phase matched transmission lines in LTCC that would be used with an IQ MZM are presented. The measured 3dB bandwidth for a set of four phase matched transmission lines for an IQ MZM was measured to be 19.8 GHz.

Comparisons of time explicit hybrid kinetic-fluid code Architect for Plasma Wakefield Acceleration with a full PIC code

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

Massimo, F., E-mail: francesco.massimo@ensta-paristech.fr; Dipartimento SBAI, Università di Roma “La Sapienza“, Via A. Scarpa 14, 00161 Roma; Atzeni, S.

Architect, a time explicit hybrid code designed to perform quick simulations for electron driven plasma wakefield acceleration, is described. In order to obtain beam quality acceptable for applications, control of the beam-plasma-dynamics is necessary. Particle in Cell (PIC) codes represent the state-of-the-art technique to investigate the underlying physics and possible experimental scenarios; however PIC codes demand the necessity of heavy computational resources. Architect code substantially reduces the need for computational resources by using a hybrid approach: relativistic electron bunches are treated kinetically as in a PIC code and the background plasma as a fluid. Cylindrical symmetry is assumed for themore » solution of the electromagnetic fields and fluid equations. In this paper both the underlying algorithms as well as a comparison with a fully three dimensional particle in cell code are reported. The comparison highlights the good agreement between the two models up to the weakly non-linear regimes. In highly non-linear regimes the two models only disagree in a localized region, where the plasma electrons expelled by the bunch close up at the end of the first plasma oscillation.« less

AP-Cloud: Adaptive Particle-in-Cloud method for optimal solutions to Vlasov–Poisson equation

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

Wang, Xingyu; Samulyak, Roman, E-mail: roman.samulyak@stonybrook.edu; Computational Science Initiative, Brookhaven National Laboratory, Upton, NY 11973

We propose a new adaptive Particle-in-Cloud (AP-Cloud) method for obtaining optimal numerical solutions to the Vlasov–Poisson equation. Unlike the traditional particle-in-cell (PIC) method, which is commonly used for solving this problem, the AP-Cloud adaptively selects computational nodes or particles to deliver higher accuracy and efficiency when the particle distribution is highly non-uniform. Unlike other adaptive techniques for PIC, our method balances the errors in PDE discretization and Monte Carlo integration, and discretizes the differential operators using a generalized finite difference (GFD) method based on a weighted least square formulation. As a result, AP-Cloud is independent of the geometric shapes ofmore » computational domains and is free of artificial parameters. Efficient and robust implementation is achieved through an octree data structure with 2:1 balance. We analyze the accuracy and convergence order of AP-Cloud theoretically, and verify the method using an electrostatic problem of a particle beam with halo. Simulation results show that the AP-Cloud method is substantially more accurate and faster than the traditional PIC, and it is free of artificial forces that are typical for some adaptive PIC techniques.« less

AP-Cloud: Adaptive particle-in-cloud method for optimal solutions to Vlasov–Poisson equation

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

Wang, Xingyu; Samulyak, Roman; Jiao, Xiangmin

We propose a new adaptive Particle-in-Cloud (AP-Cloud) method for obtaining optimal numerical solutions to the Vlasov–Poisson equation. Unlike the traditional particle-in-cell (PIC) method, which is commonly used for solving this problem, the AP-Cloud adaptively selects computational nodes or particles to deliver higher accuracy and efficiency when the particle distribution is highly non-uniform. Unlike other adaptive techniques for PIC, our method balances the errors in PDE discretization and Monte Carlo integration, and discretizes the differential operators using a generalized finite difference (GFD) method based on a weighted least square formulation. As a result, AP-Cloud is independent of the geometric shapes ofmore » computational domains and is free of artificial parameters. Efficient and robust implementation is achieved through an octree data structure with 2:1 balance. We analyze the accuracy and convergence order of AP-Cloud theoretically, and verify the method using an electrostatic problem of a particle beam with halo. Here, simulation results show that the AP-Cloud method is substantially more accurate and faster than the traditional PIC, and it is free of artificial forces that are typical for some adaptive PIC techniques.« less

Genetic and molecular characterization of the maize rp3 rust resistance locus.

PubMed Central

Webb, Craig A; Richter, Todd E; Collins, Nicholas C; Nicolas, Marie; Trick, Harold N; Pryor, Tony; Hulbert, Scot H

2002-01-01

In maize, the Rp3 gene confers resistance to common rust caused by Puccinia sorghi. Flanking marker analysis of rust-susceptible rp3 variants suggested that most of them arose via unequal crossing over, indicating that rp3 is a complex locus like rp1. The PIC13 probe identifies a nucleotide binding site-leucine-rich repeat (NBS-LRR) gene family that maps to the complex. Rp3 variants show losses of PIC13 family members relative to the resistant parents when probed with PIC13, indicating that the Rp3 gene is a member of this family. Gel blots and sequence analysis suggest that at least 9 family members are at the locus in most Rp3-carrying lines and that at least 5 of these are transcribed in the Rp3-A haplotype. The coding regions of 14 family members, isolated from three different Rp3-carrying haplotypes, had DNA sequence identities from 93 to 99%. Partial sequencing of clones of a BAC contig spanning the rp3 locus in the maize inbred line B73 identified five different PIC13 paralogues in a region of approximately 140 kb. PMID:12242248

Developing Chemistry and Kinetic Modeling Tools for Low-Temperature Plasma Simulations

NASA Astrophysics Data System (ADS)

Jenkins, Thomas; Beckwith, Kris; Davidson, Bradley; Kruger, Scott; Pankin, Alexei; Roark, Christine; Stoltz, Peter

2015-09-01

We discuss the use of proper orthogonal decomposition (POD) methods in VSim, a FDTD plasma simulation code capable of both PIC/MCC and fluid modeling. POD methods efficiently generate smooth representations of noisy self-consistent or test-particle PIC data, and are thus advantageous in computing macroscopic fluid quantities from large PIC datasets (e.g. for particle-based closure computations) and in constructing optimal visual representations of the underlying physics. They may also confer performance advantages for massively parallel simulations, due to the significant reduction in dataset sizes conferred by truncated singular-value decompositions of the PIC data. We also demonstrate how complex LTP chemistry scenarios can be modeled in VSim via an interface with MUNCHKIN, a developing standalone python/C++/SQL code that identifies reaction paths for given input species, solves 1D rate equations for the time-dependent chemical evolution of the system, and generates corresponding VSim input blocks with appropriate cross-sections/reaction rates. MUNCHKIN also computes reaction rates from user-specified distribution functions, and conducts principal path analyses to reduce the number of simulated chemical reactions. Supported by U.S. Department of Energy SBIR program, Award DE-SC0009501.

Spacecraft charging analysis with the implicit particle-in-cell code iPic3D

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

Deca, J.; Lapenta, G.; Marchand, R.

2013-10-15

We present the first results on the analysis of spacecraft charging with the implicit particle-in-cell code iPic3D, designed for running on massively parallel supercomputers. The numerical algorithm is presented, highlighting the implementation of the electrostatic solver and the immersed boundary algorithm; the latter which creates the possibility to handle complex spacecraft geometries. As a first step in the verification process, a comparison is made between the floating potential obtained with iPic3D and with Orbital Motion Limited theory for a spherical particle in a uniform stationary plasma. Second, the numerical model is verified for a CubeSat benchmark by comparing simulation resultsmore » with those of PTetra for space environment conditions with increasing levels of complexity. In particular, we consider spacecraft charging from plasma particle collection, photoelectron and secondary electron emission. The influence of a background magnetic field on the floating potential profile near the spacecraft is also considered. Although the numerical approaches in iPic3D and PTetra are rather different, good agreement is found between the two models, raising the level of confidence in both codes to predict and evaluate the complex plasma environment around spacecraft.« less

NEW DEBRIS DISKS IN NEARBY YOUNG MOVING GROUPS

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

Moór, A.; Kóspál, Á.; Ábrahám, P.

A significant fraction of nearby young moving group members harbor circumstellar debris dust disks. Due to their proximity and youth, these disks are attractive targets for studying the early evolution of debris dust and planetesimal belts. Here we present 70 and 160 μ m observations of 31 systems in the β Pic moving group, and in the Tucana–Horologium, Columba, Carina, and Argus associations, using the Herschel Space Observatory . None of these stars were observed at far-infrared wavelengths before. Our Herschel measurements were complemented by photometry from the WISE satellite for the whole sample, and by submillimeter/millimeter continuum data formore » one source, HD 48370. We identified six stars with infrared excess, four of them are new discoveries. By combining our new findings with results from the literature, we examined the incidence and general characteristics of debris disks around Sun-like members of the selected groups. With their dust temperatures of <45 K the newly identified disks around HD 38397, HD 48370, HD 160305, and BD-20 951 represent the coldest population within this sample. For HD 38397 and HD 48370, the emission is resolved in the 70 μ m Photodetector Array Camera and Spectrograph images, the estimated radius of these disks is ∼90 au. Together with the well-known disk around HD 61005, these three systems represent the highest mass end of the known debris disk population around young G-type members of the selected groups. In terms of dust content, they resemble the hypothesized debris disk of the ancient solar system.« less

Oligomerization of 2-chloroallyl alcohol by 2-pyridinecarboxylate complex of chromium(III) - new highly active and selective catalyst.

PubMed

Drzeżdżon, Joanna; Sikorski, Artur; Chmurzyński, Lech; Jacewicz, Dagmara

2018-06-05

The new 2-pyridinecarboxylate (2-pic) complex of chromium(III) has been designed and synthesized as a new highly active and selective oligomerization catalyst. The crystal structure of the new compound has been determined by X-ray diffraction. The composition and purity of [Cr(2-pic) 2 (OH 2 ) 2 ]NO 3 have been confirmed by several spectroscopic methods and the elemental analysis. Furthermore, the new complex has been investigated towards its catalytic activity for the oligomerization of 2-chloro-2-propen-1-ol under the atmospheric pressure and at room temperature. It has turned out that the novel catalyst exhibits a very high catalytic activity. Consequently, [Cr(2-pic) 2 (OH 2 ) 2 ]NO 3 belongs to a new generation of non-metallocene catalysts.

Image annotation based on positive-negative instances learning

NASA Astrophysics Data System (ADS)

Zhang, Kai; Hu, Jiwei; Liu, Quan; Lou, Ping

2017-07-01

Automatic image annotation is now a tough task in computer vision, the main sense of this tech is to deal with managing the massive image on the Internet and assisting intelligent retrieval. This paper designs a new image annotation model based on visual bag of words, using the low level features like color and texture information as well as mid-level feature as SIFT, and mixture the pic2pic, label2pic and label2label correlation to measure the correlation degree of labels and images. We aim to prune the specific features for each single label and formalize the annotation task as a learning process base on Positive-Negative Instances Learning. Experiments are performed using the Corel5K Dataset, and provide a quite promising result when comparing with other existing methods.

A PIC microcontroller-based system for real-life interfacing of external peripherals with a mobile robot

NASA Astrophysics Data System (ADS)

Singh, N. Nirmal; Chatterjee, Amitava; Rakshit, Anjan

2010-02-01

The present article describes the development of a peripheral interface controller (PIC) microcontroller-based system for interfacing external add-on peripherals with a real mobile robot, for real life applications. This system serves as an important building block of a complete integrated vision-based mobile robot system, integrated indigenously in our laboratory. The system is composed of the KOALA mobile robot in conjunction with a personal computer (PC) and a two-camera-based vision system where the PIC microcontroller is used to drive servo motors, in interrupt-driven mode, to control additional degrees of freedom of the vision system. The performance of the developed system is tested by checking it under the control of several user-specified commands, issued from the PC end.

Specific features of spin-variable properties of [Fe(acen)pic2]BPh4 · nH2O

NASA Astrophysics Data System (ADS)

Ivanova, T. A.; Ovchinnikov, I. V.; Gil'mutdinov, I. F.; Mingalieva, L. V.; Turanova, O. A.; Ivanova, G. I.

2016-02-01

The [Fe(acen)pic2]BPh4 · nH2O compound has been synthesized and studied in the temperature interval of 5-300 K by the methods of EPR and magnetic susceptibility. The existence of ferromagnetic interactions between Fe(III) complexes in this compound has been revealed, in contrast to unhydrated [Fe(acen)pic2]BPh4. The reduction in the integrated intensity of the magnetic resonance signal as the temperature decreases below 80 K has been explained by the transition of high-spin ions to the low-spin state. It has been shown that the phase transition temperature in the presence of intermolecular (ferromagnetic) interactions is lower than that in the case of noninteracting centers.

Multiscale simulation of DC corona discharge and ozone generation from nanostructures

NASA Astrophysics Data System (ADS)

Wang, Pengxiang

Atmospheric direct current (dc) corona discharge from micro-sized objects has been widely used as an ion source in many devices, such as photocopiers, laser printers, and electronic air cleaners. Shrinking the size of the discharge electrode to the nanometer range (e.g., through the use of carbon nanotubes or CNTs) is expected to lead to a significant reduction in power consumption and detrimental ozone production in these devices. The objectives of this study are to unveil the fundamental physics of the nanoscale corona discharge and to evaluate its performance and ozone production through numerical models. The extremely small size of CNTs presents considerable complexity and challenges in modeling CNT corona discharges. A hybrid multiscale model, which combines a kinetic particle-in-cell plus Monte Carlo collision (PIC-MCC) model and a continuum model, is developed to simulate the corona discharge from nanostructures. The multiscale model is developed in several steps. First, a pure PIC-MCC model is developed and PIC-MCC simulations of corona plasma from micro-sized electrode with same boundary conditions as prior model are performed to validate the PIC-MCC scheme. The agreement between the PIC-MCC model and the prior continuum model indicates the validity of the PIC-MCC scheme. The validated PIC-MCC scheme is then coupled with a continuum model to simulate the corona discharge from a micro-sized electrode. Unlike the prior continuum model which only predicts the corona plasma region, the hybrid model successfully predicts the self-consistent discharge process in the entire corona discharge gap that includes both corona plasma region and unipolar ion region. The voltage-current density curves obtained by the hybrid model agree well with analytical prediction and experimental results. The hybrid modeling approach, which combines the accuracy of a kinetic model and the efficiency of a continuum model, is thus validated for modeling dc corona discharges. For simulation of corona discharges from nanostructures, a one-dimensional (1-D) multiscale model is used due to the prohibitive computational expense associated with two-dimensional (2-D) modeling. Near the nanoscale discharge electrode surface, a kinetic model based on PIC-MCC is used due to a relatively large Knudsen number in this region. Far away from the nanoscale discharge electrode, a continuum model is used since the Knudsen number is very small there. The multiscale modeling results are compared with experimental data. The quantitative agreement in positive discharges and qualitative agreement in negative discharges validate the modeling approach. The mechanism of sustaining the discharge process from nanostructures is revealed and is found to be different from that of discharge from micro- or macro-sized electrodes. Finally, the corona plasma model is combined with a plasma chemistry model and a transport model to predict the ozone production from the nanoscale corona. The dependence of ozone production on the applied potential and air velocity is studied. The electric field distribution in a 2-D multiscale domain (from nanoscale to microscale) is predicted by solving the Poisson's equation using a finite difference scheme. The discretized linear equations are solved using a multigrid method under the framework of PETSc on a paralleled supercomputer. Although the Poisson solver is able to resolve the multiscale field, the prohibitively long computation time limits the use of a 2-D solver in the current PIC-MCC scheme.

A double-blind, placebo-controlled, exploratory trial of chromium picolinate in atypical depression: effect on carbohydrate craving.

PubMed

Docherty, John P; Sack, David A; Roffman, Mark; Finch, Manley; Komorowski, James R

2005-09-01

: In a small pilot trial, patients with atypical depression demonstrated significant positive therapeutic response to chromium picolinate. This finding is of interest because of the demonstrated link between depression, decreased insulin sensitivity, and subsequent diabetes and chromium picolinate's insulin enhancing effect. : In this double-blind, multicenter, 8-week replication study, 113 adult outpatients with atypical depression were randomized 2:1 to receive 600 mug/day of elemental chromium, as provided by chromium picolinate (CrPic), or placebo. Primary efficacy measures were the 29-item Hamilton Depression Rating Scale (HAM-D-29) and the Clinical Global Impressions Improvement Scale (CGI-I). : Of the 113 randomized patients, 110 (70 CrPic, 40 placebo) constituted the intent-to-treat (ITT) population (i.e., received at least one dose of study medication and completed at least one efficacy evaluation) and 75 (50 CrPic, 25 placebo) were evaluable (i.e., took at least 80% of study drug with no significant protocol deviations). In the evaluable population, mean age was 46 years, 69% were female, 81% were Caucasian, and mean body mass index (BMI) was 29.7. There was no significant difference between the CrPic and placebo groups in both the ITT and evaluable populations on the primary efficacy measures, with both groups showing significant improvement from baseline on total HAM-D-29 scores during the course of treatment (p < 0.0001). However, in the evaluable population, the CrPic group showed significant improvements from baseline compared with the placebo group on 4 HAM-D-29 items: appetite increase, increased eating, carbohydrate craving, and diurnal variation of feelings. A supplemental analysis of data from the subset of 41 patients in the ITT population with high carbohydrate craving (26 CrPic, 15 placebo; mean BMI = 31.1) showed that the CrPic patients had significantly greater response on total HAM-D-29 scores than the placebo group (65% vs. 33%; p < 0.05) as well as significantly greater improvements on the following HAM-D-29 items: appetite increase, increased eating, carbohydrate craving, and genital symptoms (e.g., level of libido). Chromium treatment was well-tolerated. : The study did not include a placebo run-in period, did not require minimum duration or severity of depression, and enrolled patients with major depression, dysthymia, or depression NOS. : In a population of adults with atypical depression, most of whom were overweight or obese, CrPic produced improvement on the following HAM-D-29 items: appetite increase, increased eating, carbohydrate craving, and diurnal variation of feelings. In a subpopulation of patients with high carbohydrate craving, overall HAM-D-29 scores improved significantly in patients treated with CrPic compared with placebo. The results of this study suggest that the main effect of chromium was on carbohydrate craving and appetite regulation in depressed patients and that 600 mug of elemental chromium may be beneficial for patients with atypical depression who also have severe carbohydrate craving. Further studies are needed to evaluate chromium in depressed patients specifically selected for symptoms of increased appetite and carbohydrate craving as well as to determine whether a higher dose of chromium would have an effect on mood.

Comparison of rhenium–porphyrin dyads for CO2 photoreduction: photocatalytic studies and charge separation dynamics studied by time-resolved IR spectroscopy† †Electronic supplementary information (ESI) available: NMR spectra, cyclic voltammograms, crystallographic data, fluorescence data, spectra from photoreactions and photocatalytic data. CCDC 1406000 and 1406001. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c5sc02099a

PubMed Central

Windle, Christopher D.; Summers, Peter A.; Sun, Xue Zhong; Whitwood, Adrian C.

2015-01-01

We report a study of the photocatalytic reduction of CO2 to CO by zinc porphyrins covalently linked to [ReI(2,2′-bipyridine)(CO)3L]+/0 moieties with visible light of wavelength >520 nm. Dyad 1 contains an amide C6H4NHC(O) link from porphyrin to bipyridine (Bpy), Dyad 2 contains an additional methoxybenzamide within the bridge C6H4NHC(O)C6H3(OMe)NHC(O), while Dyad 3 has a saturated bridge C6H4NHC(O)CH2; each dyad is studied with either L = Br or 3-picoline. The syntheses, spectroscopic characterisation and cyclic voltammetry of Dyad 3 Br and [Dyad 3 pic]OTf are described. The photocatalytic performance of [Dyad 3 pic]OTf in DMF/triethanolamine (5 : 1) is approximately an order of magnitude better than [Dyad 1 pic]PF6 or [Dyad 2 pic]OTf in turnover frequency and turnover number, reaching a turnover number of 360. The performance of the dyads with Re–Br units is very similar to that of the dyads with [Re–pic]+ units in spite of the adverse free energy of electron transfer. The dyads undergo reactions during photocatalysis: hydrogenation of the porphyrin to form chlorin and isobacteriochlorin units is detected by visible absorption spectroscopy, while IR spectroscopy reveals replacement of the axial ligand by a triethanolaminato group and insertion of CO2 into the latter to form a carbonate. Time-resolved IR spectra of [Dyad 2 pic]OTf and [Dyad 3 pic]OTf (560 nm excitation in CH2Cl2) demonstrated electron transfer from porphyrin to Re(Bpy) units resulting in a shift of ν(CO) bands to low wavenumbers. The rise time of the charge-separated species for [Dyad 3 pic]OTf is longest at 8 (±1) ps and its lifetime is also the longest at 320 (±15) ps. The TRIR spectra of Dyad 1 Br and Dyad 2 Br are quite different showing a mixture of 3MLCT, IL and charge-separated excited states. In the case of Dyad 3 Br, the charge-separated state is absent altogether. The TRIR spectra emphasize the very different excited states of the bromide complexes and the picoline complexes. Thus, the similarity of the photocatalytic data for bromide and picoline dyads suggests that they share common intermediates. Most likely, these involve hydrogenation of the porphyrin and substitution of the axial ligand at rhenium. PMID:29861927

Lipophilicity-related inhibition of blood platelet aggregation by nipecotic acid anilides.

PubMed

De Marco, Agostino; De Candia, Modesto; Carotti, Andrea; Cellamare, Saverio; De Candia, Erica; Altomare, Cosimo

2004-06-01

Using N-[4-(hexyloxy)phenyl]piperidine-3-carboxamide (17c) as a structural lead, a number of isomers, derivatives, and ring-opened analogs were synthesized and tested for their ability to block the in vitro aggregation of human platelets induced by adenosine 5'-diphosphate (ADP). For the most active compounds, inhibition of the platelet aggregation triggered by arachidonic acid (AA) and ADP-induced intraplatelet calcium mobilization was also demonstrated. Based on quantitative structure-activity relationships (QSARs), we proved the impact of hydrophobicity on antiplatelet activity by a nonlinear (parabolic or bilinear) relationship between pIC(50) and lipophilicity, as assessed by RP-HPLC capacity factors and ClogP (i.e. calculated 1-octanol-water partition coefficients). This study highlighted the following additional SARs: quasi-isolipophilic isomers of 17c (isonipecotanilides and pipecolinanilides) and ring-opened analogs (e.g. anilide of beta-alanine) exhibited lower antiplatelet activity; methylation of the piperidine nitrogen of 17c has no effect, whereas alkylation with an n-propyl group decreases the activity by a factor of approximately 2, most likely due to a conformation-dependent decrease in lipophilicity.

What Do You See? The Supreme Court Decision in "PICS" and the Resegregation of Two Southern School Districts

ERIC Educational Resources Information Center

Anderson, Celia Rousseau

2011-01-01

Background/Context: In June 2007, the U.S. Supreme Court ruled to prohibit student assignment on the basis of race. In Parents Involved in Community Schools v. Seattle School District No. 1 (hereafter referred to as PICS), the court deemed race-based strategies used to voluntarily desegregate school districts to be unconstitutional. Although the…

The Effects of Insulator Wall Material on Hall Thruster Discharges: A Numerical Study

DTIC Science & Technology

2001-01-03

An investigation was undertaken to determine how the choice of insulator wall material inside a Hall thruster discharge channel might affect thruster operation. In order to study this, an evolved hybrid particle-in-cell (PIC) numerical Hall thruster model, HPHall, was used. HPHall solves a set of quasi-one-dimensional fluid equations for electrons and tracks heavy particles using a PIC method.

Static and fatigue mechanical behavior of three dental CAD/CAM ceramics.

PubMed

Homaei, Ehsan; Farhangdoost, Khalil; Tsoi, James Kit Hon; Matinlinna, Jukka Pekka; Pow, Edmond Ho Nang

2016-06-01

The aim of this study was to measure the mechanical properties and fatigue behavior of three contemporary used dental ceramics, zirconia Cercon(®) (ZC), lithium disilicate e.max(®) CAD (LD), and polymer-infiltrated ceramic Enamic(®) (PIC). Flexural strength of each CAD/CAM ceramic was measured by three point bending (n=15) followed by Weibull analysis. Elastic modulus was calculated from the load-displacement curve. For cyclic fatigue loading, sinusoidal loading with a frequency of 8Hz with minimum load 3N were applied to these ceramics (n=24) using three point bending from 10(3) to 10(6) cycles. Fatigue limits of these ceramics were predicted with S-N fatigue diagram. Fracture toughness and Vickers hardness of the ceramics were measured respectively by single edge V-notch beam (SEVNB) and microindentation (Hv 0.2) methods. Chemical compositions of the materials׳ surfaces were analyzed by EDS, and microstructural analysis was conducted on the fracture surfaces by SEM. One-way ANOVA was performed and the level of significance was set at 0.05 to analyze the numerical results. The mean flexural strength of ZC, LD, and PIC was respectively 886.9, 356.7, and 135.8MPa. However, the highest Weibull modulus belonged to PIC with 19.7 and the lowest was found in LD with 7.0. The fatigue limit of maximum load for one million cycles of ZC, LD, and PIC was estimated to be 500.1, 168.4, and 73.8GPa. The mean fracture toughness of ZC, LD, and PIC was found to be respectively 6.6, 2.8, and 1.4MPam(1/2), while the mean Vickers hardness was 1641.7, 676.7, and 261.7Hv. Fracture surfaces followed fatigue loading appeared to be smoother than that after monotonic loading. Mechanical properties of ZC were substantially superior to the two other tested ceramics, but the scattering of data was the least in PIC. The fatigue limit was found to be approximately half of the mean flexural strength for all tested ceramics. Copyright © 2016 Elsevier Ltd. All rights reserved.

Chromium (D-phenylalanine)3 improves obesity-induced cardiac contractile defect in ob/ob mice.

PubMed

Dong, Feng; Yang, Xiaoping; Sreejayan, Nair; Ren, Jun

2007-11-01

Low-molecular weight chromium compounds, such as chromium picolinate [Cr(pic)(3)], improve insulin sensitivity, although toxicity is a concern. We synthesized a novel chromium complex, chromium (d-phenylalanine)(3) [Cr(d-phe)(3)], in an attempt to improve insulin sensitivity with reduced toxicity. The aim of this study was to compare the two chromium compounds on cardiac contractile function in ob/ob obese mice. C57BL lean and ob/ob obese mice were randomly divided into three groups: H(2)O, Cr(d-phe)(3), or Cr(pic)(3) (45 mug/kg per day orally for 6 months). The glucose tolerance test displayed improved glucose clearance by Cr(d-phe)(3) but not Cr(pic)(3). Myocytes from ob/ob mice exhibited depressed peak shortening (PS) and maximal velocity of shortening/relengthening (+/-dL/dt), prolonged time-to-PS and time-to-90% relengthening (TR90), reduced electrically stimulated rise in intracellular Ca(2+) (Deltafura-2 fluorescence intensity), and slowed intracellular Ca(2+) decay. Although a 3-month Cr(d-phe)(3) treatment for a separate group of ob/ob and lean 2-month-old mice only rectified reduced +/-dL/dt in ob/ob mice, all mechanical and intracellular Ca(2+) abnormalities were significantly attenuated or ablated by 6 months of Cr(d-phe)(3) but not Cr(pic)(3) treatment (except TR90). Sarco(endo)plasmic reticulum Ca(2+) ATPase activity and Na(+)-Ca(2+) exchanger expression were depressed in ob/ob mice, which were reversed by both Cr(d-phe)(3) and Cr(pic)(3), with a more pronounced effect from Cr(d-phe)(3). Cr(d-phe)(3) corrected reduced insulin-stimulated glucose uptake and improved basal phosphorylation of Akt and insulin receptor, as well as insulin-stimulated phosphorylation of Akt and insulin receptor in ob/ob myocytes. Heart homogenates from ob/ob mice had enhanced oxidative stress and protein carbonyl formation compared with the lean group, which were attenuated by both Cr(d-phe)(3) and Cr(pic)(3). Our data suggest that the new Cr(d-phe)(3) compound possesses better cardio-protective and insulin-sensitizing properties against obesity.

Inventoring Gas in Debris Disks: UV Spectroscopy of Eta Tel

NASA Astrophysics Data System (ADS)

Roberge, Aki

2015-10-01

Debris disks stand between gas-rich protoplanetary disks and mature planetary systems, shedding light on the late stages of planet formation. Their dust component has been extensively studied, yet has provided little information about disk chemical composition. More information can be provided by their gas content, but astonishingly little is known about it. Only two debris disks have measurements of their gas composition, which is shockingly carbon-rich (Beta Pictoris and 49 Ceti). Basic questions remain unanswered. What are the typical gas-to-dust ratios in debris disks? What is the chemical composition of debris gas and its parent material? The answers to these questions have profound implications for terrestrial planet assembly and the origins of planetary atmospheres.Most detections of debris gas to date were achieved with line of sight UV/optical absorption spectroscopy of edge-on disks, using the central star as the background source. This technique is far more sensitive to small amounts of gas than emission line studies. The UV bandpass is particularly important, since strong transitions of numerous atomic and molecular species lie there. We propose extending our intriguing studies of debris gas with STIS UV spectroscopy of a highly promising debris disk system, Eta Tel. This disk is edge-on and contains circumstellar atomic gas (CII). We will measure column densities of the most important gas species, find the relative elemental gas abundances, and determine the gas mass using a powerful gas disk modeling code. We will also divide our observations into two visits, to search for signs of star-grazing exocomets, which are seen in both Beta Pic and 49 Cet.

Oral Vitamin A and Retinoic Acid Supplementation Stimulates Antibody Production and Splenic Stra6 Expression in Tetanus Toxoid–Immunized Mice12

PubMed Central

Tan, Libo; Wray, Amanda E.; Ross, A. Catharine

2012-01-01

Coadministration of retinoic acid (RA) and polyinosinic acid:polycytidylic acid (PIC) has been shown to cooperatively enhance the anti–tetanus toxoid (anti-TT) vaccine response in adult mice. Germinal center formation in the spleen is critical for a normal antibody response. Recent studies have identified Stimulated by Retinoic Acid-6 (Stra6) as the cell membrane receptor for retinol-binding protein (RBP) in many organs, including spleen. The objectives of the present studies were to test whether orally administered vitamin A (VA) itself, either alone or combined with RA, and/or treatment with PIC regulates Stra6 gene expression in mouse spleen and, concomitantly, antibody production. Eight-week-old C57BL/6 mice were immunized with TT. In an initial kinetic study, oral VA (6 mg/kg) increased anti-TT IgM and IgG production as well as splenic Stra6 mRNA expression. In treatment studies that were analyzed 9 d postimmunization, retinoids including VA, RA, VA and RA combined, and PIC significantly increased plasma anti-TT IgM and IgG (P < 0.05) and splenic Stra6 mRNA (P < 0.05). Treatments that included PIC elevated plasma anti-TT IgM and IgG concentrations >20-fold (P < 0.01). Immunohistochemistry of STRA6 protein in mouse spleen confirmed its increase after immunization and retinoid treatment. In conclusion, retinoid treatments that included VA, RA, VA and RA combined, and the combination of retinoid and PIC stimulated the expression of Stra6 in spleen, which potentially could increase the local uptake of retinol. Concomitantly, these treatments increased the systemic antigen-specific antibody response. The ability of oral retinoids to stimulate systemic immunity has implications for public health and therapeutic use of VA. PMID:22739370

Control of ammonia and urea emissions from urea manufacturing facilities of Petrochemical Industries Company (PIC), Kuwait.

PubMed

Khan, A R; Al-Awadi, L; Al-Rashidi, M S

2016-06-01

Petrochemical Industries Company (PIC) in Kuwait has mitigated the pollution problem of ammonia and urea dust by replacing the melting and prilling units of finished-product urea prills with an environmentally friendly granulation process. PIC has financed a research project conducted by the Coastal and Air Pollution Program's research staff at the Kuwait Institute for Scientific Research to assess the impact of pollution control strategies implemented to maintain a healthy productive environment in and around the manufacturing premises. The project was completed in three phases: the first phase included the pollution monitoring of the melting and prilling units in full operation, the second phase covered the complete shutdown period where production was halted completely and granulation units were installed, and the last phase encompassed the current modified status with granulation units in full operation. There was substantial decrease in ammonia emissions, about 72%, and a 52.7% decrease in urea emissions with the present upgrading of old melting and prilling units to a state-of-the-art technology "granulation process" for a final finished product. The other pollutants, sulfur dioxide (SO2), nitrogen oxides (NOx), and volatile organic compounds (VOCs), have not shown any significant change, as the present modification has not affected the sources of these pollutants. Petrochemical Industries Company (PIC) in Kuwait has ammonia urea industries, and there were complaints about ammonia and urea dust pollution. PIC has resolved this problem by replacing "melting and prilling unit" of final product urea prills by more environmentally friendly "granulation unit." Environmental Pollution and Climate Program has been assigned the duty of assessing the outcome of this change and how that influenced ammonia and urea dust emissions from the urea manufacturing plant.

The taxonomy and diversity of Platerodrilus (Coleoptera, Lycidae) inferred from molecular data and morphology of adults and larvae

PubMed Central

Masek, Michal; Bocak, Ladislav

2014-01-01

Abstract The Oriental neotenic net-winged beetles attracted attention of biologists due to conspicuous large-bodied females; nevertheless phylogenetic relationships remain contentious and only a few species are known in both the fully metamorphosed males and neotenic females. The phylogenetic analyses and morphology of larvae and adults provide data for investigation of relationships and species delineation. Platrilus Kazantsev, 2009, Platerodriloplesius Wittmer, 1944, and Falsocalochromus Pic, 1942 are synonymized to Platerodrilus Pic, 1921. Platrilus hirtus (Wittmer, 1938) and Pl. crassicornis (Pic, 1923) are transferred to Platerodrilus Pic, 1921. Platerodrilus hoiseni Wong, 1996 is proposed as a junior subjective synonym of Falsocalochromus ruficollis Pic, 1942. Platerodrilus is divided in three species-groups: P. paradoxus, P. major, and P. sinuatus groups defined based on the shape of genitalia and molecular phylogeny. The following species are described: Platerodrilus foliaceus sp. n., P. wongi sp. n. (P. paradoxus group); P. ngi sp. n., P. wittmeri (P. major group), P. ijenensis sp. n., P. luteus sp. n., P. maninjauensis sp. n., P. montanus sp. n., P. palawanensis sp. n., P. ranauensis sp. n., P. sibayakensis sp. n., P. sinabungensis sp. n., P. talamauensis sp. n., and P. tujuhensis sp. n. (P. sinuatus group). P. korinchiana robinsoni Blair, 1928 is elevated to the species rank as P. robinsoni Blair, 1928, stat. n. The conspecific semaphoronts are identified using molecular phylogeny for P. foliaceus sp. n., P. tujuhensis sp. n., P. montanus sp. n., P. maninjauensis sp. n.; additional female larvae are assigned to the species-groups. Diagnostic characters are illustrated and keys are provided for P. paradoxus and P. major groups. PMID:25147457

An enzyme in the kynurenine pathway that governs vulnerability to suicidal behavior by regulating excitotoxicity and neuroinflammation

PubMed Central

Brundin, L; Sellgren, C M; Lim, C K; Grit, J; Pålsson, E; Landén, M; Samuelsson, M; Lundgren, K; Brundin, P; Fuchs, D; Postolache, T T; Traskman-Bendz, L; Guillemin, G J; Erhardt, S

2016-01-01

Emerging evidence suggests that inflammation has a key role in depression and suicidal behavior. The kynurenine pathway is involved in neuroinflammation and regulates glutamate neurotransmission. In the cerebrospinal fluid (CSF) of suicidal patients, levels of inflammatory cytokines and the kynurenine metabolite quinolinic acid (QUIN), an N-methyl-d-aspartate receptor agonist, are increased. The enzyme amino-β-carboxymuconate-semialdehyde-decarboxylase (ACMSD) limits QUIN formation by competitive production of the neuroprotective metabolite picolinic acid (PIC). Therefore, decreased ACMSD activity can lead to excess QUIN. We tested the hypothesis that deficient ACMSD activity underlies suicidal behavior. We measured PIC and QUIN in CSF and plasma samples from 137 patients exhibiting suicidal behavior and 71 healthy controls. We used DSM-IV and the Montgomery-Åsberg Depression Rating Scale and Suicide Assessment Scale to assess behavioral changes. Finally, we genotyped ACMSD tag single-nucleotide polymorphisms (SNPs) in 77 of the patients and 150 population-based controls. Suicide attempters had reduced PIC and a decreased PIC/QUIN ratio in both CSF (P<0.001) and blood (P=0.001 and P<0.01, respectively). The reductions of PIC in CSF were sustained over 2 years after the suicide attempt based on repeated measures. The minor C allele of the ACMSD SNP rs2121337 was more prevalent in suicide attempters and associated with increased CSF QUIN. Taken together, our data suggest that increased QUIN levels may result from reduced activity of ACMSD in suicidal subjects. We conclude that measures of kynurenine metabolites can be explored as biomarkers of suicide risk, and that ACMSD is a potential therapeutic target in suicidal behavior. PMID:27483383

A Particle Module for the PLUTO Code. I. An Implementation of the MHD–PIC Equations

NASA Astrophysics Data System (ADS)

Mignone, A.; Bodo, G.; Vaidya, B.; Mattia, G.

2018-05-01

We describe an implementation of a particle physics module available for the PLUTO code appropriate for the dynamical evolution of a plasma consisting of a thermal fluid and a nonthermal component represented by relativistic charged particles or cosmic rays (CRs). While the fluid is approached using standard numerical schemes for magnetohydrodynamics, CR particles are treated kinetically using conventional Particle-In-Cell (PIC) techniques. The module can be used either to describe test-particle motion in the fluid electromagnetic field or to solve the fully coupled magnetohydrodynamics (MHD)–PIC system of equations with particle backreaction on the fluid as originally introduced by Bai et al. Particle backreaction on the fluid is included in the form of momentum–energy feedback and by introducing the CR-induced Hall term in Ohm’s law. The hybrid MHD–PIC module can be employed to study CR kinetic effects on scales larger than the (ion) skin depth provided that the Larmor gyration scale is properly resolved. When applicable, this formulation avoids resolving microscopic scales, offering substantial computational savings with respect to PIC simulations. We present a fully conservative formulation that is second-order accurate in time and space, and extends to either the Runge–Kutta (RK) or the corner transport upwind time-stepping schemes (for the fluid), while a standard Boris integrator is employed for the particles. For highly energetic relativistic CRs and in order to overcome the time-step restriction, a novel subcycling strategy that retains second-order accuracy in time is presented. Numerical benchmarks and applications including Bell instability, diffusive shock acceleration, and test-particle acceleration in reconnecting layers are discussed.

Antidiabetogenic Effects of Chromium Mitigate Hyperinsulinemia-Induced Cellular Insulin Resistance via Correction of Plasma Membrane Cholesterol Imbalance

PubMed Central

Horvath, Emily M.; Tackett, Lixuan; McCarthy, Alicia M.; Raman, Priya; Brozinick, Joseph T.; Elmendorf, Jeffrey S.

2008-01-01

Previously, we found that a loss of plasma membrane (PM) phosphatidylinositol 4,5-bisphosphate (PIP2)-regulated filamentous actin (F-actin) structure contributes to insulin-induced insulin resistance. Interestingly, we also demonstrated that chromium picolinate (CrPic), a dietary supplement thought to improve glycemic status in insulin-resistant individuals, augments insulin-regulated glucose transport in insulin-sensitive 3T3-L1 adipocytes by lowering PM cholesterol. Here, to gain mechanistic understanding of these separate observations, we tested the prediction that CrPic would protect against insulin-induced insulin resistance by improving PM features important in cytoskeletal structure and insulin sensitivity. We found that insulin-induced insulin-resistant adipocytes display elevated PM cholesterol with a reciprocal decrease in PM PIP2. This lipid imbalance and insulin resistance was corrected by the cholesterol-lowering action of CrPic. The PM lipid imbalance did not impair insulin signaling, nor did CrPic amplify insulin signal transduction. In contrast, PM analyses corroborated cholesterol and PIP2 interactions influencing cytoskeletal structure. Because extensive in vitro study documents an essential role for cytoskeletal capacity in insulin-regulated glucose transport, we next evaluated intact skeletal muscle from obese, insulin-resistant Zucker (fa/fa) rats. Because insulin resistance in these animals likely involves multiple mechanisms, findings that cholesterol-lowering restored F-actin cytoskeletal structure and insulin sensitivity to that witnessed in lean control muscle were striking. Also, experiments using methyl-β-cyclodextrin to shuttle cholesterol into or out of membranes respectively recapitulated the insulin-induced insulin-resistance and protective effects of CrPic on membrane/cytoskeletal interactions and insulin sensitivity. These data predict a PM cholesterol basis for hyperinsulinemia-associated insulin resistance and importantly highlight the reversible nature of this abnormality. PMID:18165437

Renal and Glycemic Effects of High-Dose Chromium Picolinate in db/db Mice: Assessment of DNA Damage

PubMed Central

Mozaffari, Mahmood S.; Baban, Babak; Abdelsayed, Rafik; Liu, Jun Yao; Wimborne, Hereward; Rodriguez, Nancy; Abebe, Worku

2011-01-01

This study examined renal and glycemic effects of chromium picolinate (Cr(pic)3) supplementation in the context of its purported potential for DNA damage. In preventional protocol, male obese diabetic db/db mice were fed diets either lacking or containing 5, 10 or 100 mg/kg chromium as Cr(pic)3 from 6 to 24 weeks of age; male lean nondiabetic db/m mice served as controls. Untreated db/db mice displayed increased plasma glucose and insulin, hemoglobin A1c, renal tissue advanced glycation end (AGE) products, albuminuria, glomerular mesangial expansion, urinary 8-hydroxydeoxyguanosine (8-OHdG, an index of oxidative DNA damage) and renal tissue immunostaining for γH2AX (a marker of double-strand DNA breaks) compared to db/m controls. Creatinine clearance was lower while blood pressure was similar between untreated db/db mice and their db/m controls. High Cr(pic)3 intake (i.e., 100 mg/kg diet) mildly improved glycemic status and albuminuria without affecting blood pressure or creatinine clearance. Treatment with Cr(pic)3 did not increase DNA damage despite marked renal accumulation of chromium. In interventional protocol, effects of diets containing 0, 100 and 250 mg/kg supplemental chromium, from 12 to 24 weeks of age, were examined in db/db mice. The results generally revealed similar effects to those of the 100 mg/kg diet of the preventional protocol. In conclusion, the severely hyperglycemic db/db mouse displays renal structural and functional abnormalities in association with DNA damage. High-dose Cr(pic)3 treatment mildly improves glycemic control and it causes moderate reduction in albuminuria, without affecting histopathological appearance of the kidney and increasing the risk for DNA damage. PMID:21959055

Anti-diabetic activity of chromium picolinate and biotin in rats with type 2 diabetes induced by high-fat diet and streptozotocin.

PubMed

Sahin, Kazim; Tuzcu, Mehmet; Orhan, Cemal; Sahin, Nurhan; Kucuk, Osman; Ozercan, Ibrahim H; Juturu, Vijaya; Komorowski, James R

2013-07-28

The objective of the present study was to evaluate anti-diabetic effects of chromium picolinate (CrPic) and biotin supplementations in type 2 diabetic rats. The type 2 diabetic rat model was induced by high-fat diet (HFD) and low-dose streptozotocin. The rats were divided into five groups as follows: (1) non-diabetic rats fed a regular diet; (2) diabetic rats fed a HFD; (3) diabetic rats fed a HFD and supplemented with CrPic (80 μg/kg body weight (BW) per d); (4) diabetic rats fed a HFD and supplemented with biotin (300 μg/kg BW per d); (5) diabetic rats fed a HFD and supplemented with both CrPic and biotin. Circulating glucose, cortisol, total cholesterol, TAG, NEFA and malondialdehyde concentrations decreased (P< 0·05), but serum insulin concentrations increased (P< 0·05) in diabetic rats treated with biotin and CrPic, particularly with a combination of the supplements. Feeding a HFD to diabetic rats decreased PPAR-γ expression in adipose tissue and phosphorylated insulin receptor substrate 1 (p-IRS-1) expression of liver, kidney and muscle tissues, while the supplements increased (P< 0·001) PPAR-γ and p-IRS-1 expressions in relevant tissues. Expression of NF-κB in the liver and kidney was greater in diabetic rats fed a HFD, as compared with rats fed a regular diet (P< 0·01). The supplements decreased the expression of NF-κB in diabetic rats (P< 0·05). Results of the present study revealed that supplementing CrPic and biotin alone or in a combination exerts anti-diabetic activities, probably through modulation of PPAR-γ, IRS-1 and NF-κB proteins.

Renal and glycemic effects of high-dose chromium picolinate in db/db mice: assessment of DNA damage.

PubMed

Mozaffari, Mahmood S; Baban, Babak; Abdelsayed, Rafik; Liu, Jun Yao; Wimborne, Hereward; Rodriguez, Nancy; Abebe, Worku

2012-08-01

This study examined renal and glycemic effects of chromium picolinate [Cr(pic)3] supplementation in the context of its purported potential for DNA damage. In preventional protocol, male obese diabetic db/db mice were fed diets either lacking or containing 5, 10 or 100 mg/kg chromium as Cr(pic)3 from 6 to 24 weeks of age; male lean nondiabetic db/m mice served as controls. Untreated db/db mice displayed increased plasma glucose and insulin, hemoglobin A1c, renal tissue advanced glycation end products, albuminuria, glomerular mesangial expansion, urinary 8-hydroxydeoxyguanosine (an index of oxidative DNA damage) and renal tissue immunostaining for γH2AX (a marker of double-strand DNA breaks) compared to db/m controls. Creatinine clearance was lower in untreated db/db mice than their db/m controls, while blood pressure was similar. High Cr(pic)3 intake (i.e., 100-mg/kg diet) mildly improved glycemic status and albuminuria without affecting blood pressure or creatinine clearance. Treatment with Cr(pic)3 did not increase DNA damage despite marked renal accumulation of chromium. In interventional protocol, effects of diets containing 0, 100 and 250 mg/kg supplemental chromium, from 12 to 24 weeks of age, were examined in db/db mice. The results generally revealed similar effects to those of the 100-mg/kg diet of the preventional protocol. In conclusion, the severely hyperglycemic db/db mouse displays renal structural and functional abnormalities in association with DNA damage. High-dose Cr(pic)3 treatment mildly improves glycemic control, and it causes moderate reduction in albuminuria, without affecting the histopathological appearance of the kidney and increasing the risk for DNA damage. Copyright © 2012 Elsevier Inc. All rights reserved.

Triple-Layer Plastic Bags Protect Dry Common Beans (Phaseolus vulgaris) Against Damage by Acanthoscelides obtectus (Coleoptera: Chrysomelidae) During Storage.

PubMed

Mutungi, C; Affognon, H D; Njoroge, A W; Manono, J; Baributsa, D; Murdock, L L

2015-10-01

Fumigated dry common beans (Phaseolus vulgaris L.) that were artificially infested with Acanthoscelides obtectus Say, and others that were not artificially infested, were stored in hermetic triple-layer PICS (Lela Agro, Kano, Nigeria) or woven polypropylene (PP) bags for 6 mo at ambient laboratory temperature conditions of 22.6 ± 1.9°C and 60.1 ± 4.3% relative humidity. In an additional trial, beans contained in PP bags were treated with Actellic Super dust before introducing A. obtectus. Moisture content, number of live adult A. obtectus, seed damage, weight loss, and seed germination were determined at monthly intervals. At 6 mo, beans stored in PICS bags retained higher moisture than those stored in PP bags, but in all treatments the moisture level remained below that recommended for safe storage of beans. In the PICS bags, proliferation of A. obtectus did not proceed and at 6 mo, beans stored in these bags did not have insect-inflicted seed damage or weight loss. In contrast, seed damage and weight loss in PP bags exceeded economic threshold after 1 mo in the absence of Actellic Super dust (Syngenta Crop protection AG, Basle, Switzerland), and after 2 mo in the presence of it. Germination of beans stored in PP bags decreased greatly whereas the beans stored in PICS bags did not show reduced germination. Chemical free storage of common beans in PICS bags protects them against damage by A. obtectus. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Rise time of proton cut-off energy in 2D and 3D PIC simulations

NASA Astrophysics Data System (ADS)

Babaei, J.; Gizzi, L. A.; Londrillo, P.; Mirzanejad, S.; Rovelli, T.; Sinigardi, S.; Turchetti, G.

2017-04-01

The Target Normal Sheath Acceleration regime for proton acceleration by laser pulses is experimentally consolidated and fairly well understood. However, uncertainties remain in the analysis of particle-in-cell simulation results. The energy spectrum is exponential with a cut-off, but the maximum energy depends on the simulation time, following different laws in two and three dimensional (2D, 3D) PIC simulations so that the determination of an asymptotic value has some arbitrariness. We propose two empirical laws for the rise time of the cut-off energy in 2D and 3D PIC simulations, suggested by a model in which the proton acceleration is due to a surface charge distribution on the target rear side. The kinetic energy of the protons that we obtain follows two distinct laws, which appear to be nicely satisfied by PIC simulations, for a model target given by a uniform foil plus a contaminant layer that is hydrogen-rich. The laws depend on two parameters: the scaling time, at which the energy starts to rise, and the asymptotic cut-off energy. The values of the cut-off energy, obtained by fitting 2D and 3D simulations for the same target and laser pulse configuration, are comparable. This suggests that parametric scans can be performed with 2D simulations since 3D ones are computationally very expensive, delegating their role only to a correspondence check. In this paper, the simulations are carried out with the PIC code ALaDyn by changing the target thickness L and the incidence angle α, with a fixed a0 = 3. A monotonic dependence, on L for normal incidence and on α for fixed L, is found, as in the experimental results for high temporal contrast pulses.

Structural characterization of human general transcription factor TFIIF in solution

PubMed Central

Akashi, Satoko; Nagakura, Shinjiro; Yamamoto, Seiji; Okuda, Masahiko; Ohkuma, Yoshiaki; Nishimura, Yoshifumi

2008-01-01

Human general transcription factor IIF (TFIIF), a component of the transcription pre-initiation complex (PIC) associated with RNA polymerase II (Pol II), was characterized by size-exclusion chromatography (SEC), electrospray ionization mass spectrometry (ESI-MS), and chemical cross-linking. Recombinant TFIIF, composed of an equimolar ratio of α and β subunits, was bacterially expressed, purified to homogeneity, and found to have a transcription activity similar to a natural one in the human in vitro transcription system. SEC of purified TFIIF, as previously reported, suggested that this protein has a size >200 kDa. In contrast, ESI-MS of the purified sample gave a molecular size of 87 kDa, indicating that TFIIF is an αβ heterodimer, which was confirmed by matrix-assisted laser desorption/ionization (MALDI) MS of the cross-linked TFIIF components. Recent electron microscopy (EM) and photo-cross-linking studies showed that the yeast TFIIF homolog containing Tfg1 and Tfg2, corresponding to the human α and β subunits, exists as a heterodimer in the PIC, so the human TFIIF is also likely to exist as a heterodimer even in the PIC. In the yeast PIC, EM and photo-cross-linking studies showed different results for the mutual location of TFIIE and TFIIF along DNA. We have examined the direct interaction between human TFIIF and TFIIE by ESI-MS, SEC, and chemical cross-linking; however, no direct interaction was observed, at least in solution. This is consistent with the previous photo-cross-linking observation that TFIIF and TFIIE flank DNA separately on both sides of the Pol II central cleft in the yeast PIC. PMID:18218714

Image retrieval and processing system version 2.0 development work

NASA Technical Reports Server (NTRS)

Slavney, Susan H.; Guinness, Edward A.

1991-01-01

The Image Retrieval and Processing System (IRPS) is a software package developed at Washington University and used by the NASA Regional Planetary Image Facilities (RPIF's). The IRPS combines data base management and image processing components to allow the user to examine catalogs of image data, locate the data of interest, and perform radiometric and geometric calibration of the data in preparation for analysis. Version 1.0 of IRPS was completed in Aug. 1989 and was installed at several IRPS's. Other RPIF's use remote logins via NASA Science Internet to access IRPS at Washington University. Work was begun on designing and population a catalog of Magellan image products that will be part of IRPS Version 2.0, planned for release by the end of calendar year 1991. With this catalog, a user will be able to search by orbit and by location for Magellan Basic Image Data Records (BIDR's), Mosaicked Image Data Records (MIDR's), and Altimetry-Radiometry Composite Data Records (ARCDR's). The catalog will include the Magellan CD-ROM volume, director, and file name for each data product. The image processing component of IRPS is based on the Planetary Image Cartography Software (PICS) developed by the U.S. Geological Survey, Flagstaff, Arizona. To augment PICS capabilities, a set of image processing programs were developed that are compatible with PICS-format images. This software includes general-purpose functions that PICS does not have, analysis and utility programs for specific data sets, and programs from other sources that were modified to work with PICS images. Some of the software will be integrated into the Version 2.0 release of IRPS. A table is presented that lists the programs with a brief functional description of each.

Low-voltage high-performance silicon photonic devices and photonic integrated circuits operating up to 30 Gb/s.

PubMed

Kim, Gyungock; Park, Jeong Woo; Kim, In Gyoo; Kim, Sanghoon; Kim, Sanggi; Lee, Jong Moo; Park, Gun Sik; Joo, Jiho; Jang, Ki-Seok; Oh, Jin Hyuk; Kim, Sun Ae; Kim, Jong Hoon; Lee, Jun Young; Park, Jong Moon; Kim, Do-Won; Jeong, Deog-Kyoon; Hwang, Moon-Sang; Kim, Jeong-Kyoum; Park, Kyu-Sang; Chi, Han-Kyu; Kim, Hyun-Chang; Kim, Dong-Wook; Cho, Mu Hee

2011-12-19

We present high performance silicon photonic circuits (PICs) defined for off-chip or on-chip photonic interconnects, where PN depletion Mach-Zehnder modulators and evanescent-coupled waveguide Ge-on-Si photodetectors were monolithically integrated on an SOI wafer with CMOS-compatible process. The fabricated silicon PIC(off-chip) for off-chip optical interconnects showed operation up to 30 Gb/s. Under differential drive of low-voltage 1.2 V(pp), the integrated 1 mm-phase-shifter modulator in the PIC(off-chip) demonstrated an extinction ratio (ER) of 10.5dB for 12.5 Gb/s, an ER of 9.1dB for 20 Gb/s, and an ER of 7.2 dB for 30 Gb/s operation, without adoption of travelling-wave electrodes. The device showed the modulation efficiency of V(π)L(π) ~1.59 Vcm, and the phase-shifter loss of 3.2 dB/mm for maximum optical transmission. The Ge photodetector, which allows simpler integration process based on reduced pressure chemical vapor deposition exhibited operation over 30 Gb/s with a low dark current of 700 nA at -1V. The fabricated silicon PIC(intra-chip) for on-chip (intra-chip) photonic interconnects, where the monolithically integrated modulator and Ge photodetector were connected by a silicon waveguide on the same chip, showed on-chip data transmissions up to 20 Gb/s, indicating potential application in future silicon on-chip optical network. We also report the performance of the hybrid silicon electronic-photonic IC (EPIC), where a PIC(intra-chip) chip and 0.13μm CMOS interface IC chips were hybrid-integrated.

PIC codes for plasma accelerators on emerging computer architectures (GPUS, Multicore/Manycore CPUS)

NASA Astrophysics Data System (ADS)

Vincenti, Henri

2016-03-01

The advent of exascale computers will enable 3D simulations of a new laser-plasma interaction regimes that were previously out of reach of current Petasale computers. However, the paradigm used to write current PIC codes will have to change in order to fully exploit the potentialities of these new computing architectures. Indeed, achieving Exascale computing facilities in the next decade will be a great challenge in terms of energy consumption and will imply hardware developments directly impacting our way of implementing PIC codes. As data movement (from die to network) is by far the most energy consuming part of an algorithm future computers will tend to increase memory locality at the hardware level and reduce energy consumption related to data movement by using more and more cores on each compute nodes (''fat nodes'') that will have a reduced clock speed to allow for efficient cooling. To compensate for frequency decrease, CPU machine vendors are making use of long SIMD instruction registers that are able to process multiple data with one arithmetic operator in one clock cycle. SIMD register length is expected to double every four years. GPU's also have a reduced clock speed per core and can process Multiple Instructions on Multiple Datas (MIMD). At the software level Particle-In-Cell (PIC) codes will thus have to achieve both good memory locality and vectorization (for Multicore/Manycore CPU) to fully take advantage of these upcoming architectures. In this talk, we present the portable solutions we implemented in our high performance skeleton PIC code PICSAR to both achieve good memory locality and cache reuse as well as good vectorization on SIMD architectures. We also present the portable solutions used to parallelize the Pseudo-sepctral quasi-cylindrical code FBPIC on GPUs using the Numba python compiler.

Plans, Patterns, and Move Categories Guiding a Highly Selective Search

NASA Astrophysics Data System (ADS)

Trippen, Gerhard

In this paper we present our ideas for an Arimaa-playing program (also called a bot) that uses plans and pattern matching to guide a highly selective search. We restrict move generation to moves in certain move categories to reduce the number of moves considered by the bot significantly. Arimaa is a modern board game that can be played with a standard Chess set. However, the rules of the game are not at all like those of Chess. Furthermore, Arimaa was designed to be as simple and intuitive as possible for humans, yet challenging for computers. While all established Arimaa bots use alpha-beta search with a variety of pruning techniques and other heuristics ending in an extensive positional leaf node evaluation, our new bot, Rat, starts with a positional evaluation of the current position. Based on features found in the current position - supported by pattern matching using a directed position graph - our bot Rat decides which of a given set of plans to follow. The plan then dictates what types of moves can be chosen. This is another major difference from bots that generate "all" possible moves for a particular position. Rat is only allowed to generate moves that belong to certain categories. Leaf nodes are evaluated only by a straightforward material evaluation to help avoid moves that lose material. This highly selective search looks, on average, at only 5 moves out of 5,000 to over 40,000 possible moves in a middle game position.

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

Lange, R.; Dickerson, M.A.; Peterson, K.R.

Two numerical models for the calculation of air concentration and ground deposition of airborne effluent releases are compared. The Particle-in-Cell (PIC) model and the Straight-Line Airflow Gaussian model were used for the simulation. Two sites were selected for comparison: the Hudson River Valley, New York, and the area around the Savannah River Plant, South Carolina. Input for the models was synthesized from meteorological data gathered in previous studies by various investigators. It was found that the PIC model more closely simulated the three-dimensional effects of the meteorology and topography. Overall, the Gaussian model calculated higher concentrations under stable conditions withmore » better agreement between the two methods during neutral to unstable conditions. In addition, because of its consideration of exposure from the returning plume after flow reversal, the PIC model calculated air concentrations over larger areas than did the Gaussian model.« less

Limb shape observations at the Pic du Midi Observatory. Determination of the solar gravitational moments

NASA Astrophysics Data System (ADS)

Rozelot, J. P.; Lefebvre, S.

The accurate shape of the Sun has been actively debated since 1974. So far, balloon and satellite experiments achieved the required sensibility to measure the expected small asphericities of the solar limb shape. However, exceptional good meteorological conditions encountered during several missions at the Pic du Midi Observatory have permitted to measure the coefficients shape of the solar limb on the two first Legendre polynomials expansion. In theory, this photospheric outer shape is sensitive to the interior rate, and asphericities can be explained both in terms of gravitational moments and thermal wind. We present observations made at the Pic du Midi Observatory and we compare results with these obtained by SDS (Sofia et al., 1994, 1996) and SOHO/MDI (Kuhn, 1999). The accepted and dedicated PICARD space mission on this subject is briefly presented.

Relativistic extension of a charge-conservative finite element solver for time-dependent Maxwell-Vlasov equations

NASA Astrophysics Data System (ADS)

Na, D.-Y.; Moon, H.; Omelchenko, Y. A.; Teixeira, F. L.

2018-01-01

Accurate modeling of relativistic particle motion is essential for physical predictions in many problems involving vacuum electronic devices, particle accelerators, and relativistic plasmas. A local, explicit, and charge-conserving finite-element time-domain (FETD) particle-in-cell (PIC) algorithm for time-dependent (non-relativistic) Maxwell-Vlasov equations on irregular (unstructured) meshes was recently developed by Moon et al. [Comput. Phys. Commun. 194, 43 (2015); IEEE Trans. Plasma Sci. 44, 1353 (2016)]. Here, we extend this FETD-PIC algorithm to the relativistic regime by implementing and comparing three relativistic particle-pushers: (relativistic) Boris, Vay, and Higuera-Cary. We illustrate the application of the proposed relativistic FETD-PIC algorithm for the analysis of particle cyclotron motion at relativistic speeds, harmonic particle oscillation in the Lorentz-boosted frame, and relativistic Bernstein modes in magnetized charge-neutral (pair) plasmas.

Effects of laser-plasma instabilities on hydro evolution in an OMEGA-EP long-scale-length experiment

DOE PAGES

Li, J.; Hu, S. X.; Ren, C.

2017-02-28

Laser-plasma instabilities and hydro evolution of the coronal plasma in an OMEGA EP long-scale-length experiment with planar targets were studied with particle-in-cell (PIC) and hydrodynamic simulations. Plasma and laser conditions were first obtained in a two-dimensional DRACO hydro simulation with only inverse-bremsstrahlung absorption. Using these conditions, an OSIRIS PIC simulation was performed to study laser absorption and hot-electron generation caused by laser-plasma instabilities (LPIs) near the quarter-critical region. The obtained PIC information was subsequently coupled to another DRACO simulation to examine how the LPIs affect the overall hydrodynamics. Lastly, the results showed that the LPI-induced laser absorption increased the electronmore » temperature but did not significantly change the density scale length in the corona.« less

Continuously differentiable PIC shape functions for triangular meshes

DOE PAGES

Barnes, D. C.

2018-03-21

In this study, a new class of continuously-differentiable shape functions is developed and applied to two-dimensional electrostatic PIC simulation on an unstructured simplex (triangle) mesh. It is shown that troublesome aliasing instabilities are avoided for cold plasma simulation in which the Debye length is as small as 0.01 cell sizes. These new shape functions satisfy all requirements for PIC particle shape. They are non-negative, have compact support, and partition unity. They are given explicitly by cubic expressions in the usual triangle logical (areal) coordinates. The shape functions are not finite elements because their structure depends on the topology of themore » mesh, in particular, the number of triangles neighboring each mesh vertex. Nevertheless, they may be useful as approximations to solution of other problems in which continuity of derivatives is required or desired.« less

Efficient Modeling of Laser-Plasma Accelerators with INF&RNO

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

Benedetti, C.; Schroeder, C. B.; Esarey, E.

2010-06-01

The numerical modeling code INF&RNO (INtegrated Fluid& paRticle simulatioN cOde, pronounced"inferno") is presented. INF&RNO is an efficient 2D cylindrical code to model the interaction of a short laser pulse with an underdense plasma. The code is based on an envelope model for the laser while either a PIC or a fluid description can be used for the plasma. The effect of the laser pulse on the plasma is modeled with the time-averaged poderomotive force. These and other features allow for a speedup of 2-4 orders of magnitude compared to standard full PIC simulations while still retaining physical fidelity. The codemore » has been benchmarked against analytical solutions and 3D PIC simulations and here a set of validation tests together with a discussion of the performances are presented.« less

Efficient Modeling of Laser-Plasma Accelerators with INF&RNO

NASA Astrophysics Data System (ADS)

Benedetti, C.; Schroeder, C. B.; Esarey, E.; Geddes, C. G. R.; Leemans, W. P.

2010-11-01

The numerical modeling code INF&RNO (INtegrated Fluid & paRticle simulatioN cOde, pronounced "inferno") is presented. INF&RNO is an efficient 2D cylindrical code to model the interaction of a short laser pulse with an underdense plasma. The code is based on an envelope model for the laser while either a PIC or a fluid description can be used for the plasma. The effect of the laser pulse on the plasma is modeled with the time-averaged poderomotive force. These and other features allow for a speedup of 2-4 orders of magnitude compared to standard full PIC simulations while still retaining physical fidelity. The code has been benchmarked against analytical solutions and 3D PIC simulations and here a set of validation tests together with a discussion of the performances are presented.

Common-signal-induced synchronization in photonic integrated circuits and its application to secure key distribution.

PubMed

Sasaki, Takuma; Kakesu, Izumi; Mitsui, Yusuke; Rontani, Damien; Uchida, Atsushi; Sunada, Satoshi; Yoshimura, Kazuyuki; Inubushi, Masanobu

2017-10-16

We experimentally achieve common-signal-induced synchronization in two photonic integrated circuits with short external cavities driven by a constant-amplitude random-phase light. The degree of synchronization can be controlled by changing the optical feedback phase of the two photonic integrated circuits. The change in the optical feedback phase leads to a significant redistribution of the spectral energy of optical and RF spectra, which is a unique characteristic of PICs with the short external cavity. The matching of the RF and optical spectra is necessary to achieve synchronization between the two PICs, and stable synchronization can be obtained over an hour in the presence of optical feedback. We succeed in generating information-theoretic secure keys and achieving the final key generation rate of 184 kb/s using the PICs.

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

Qin, Hong; Liu, Jian; Xiao, Jianyuan

Particle-in-cell (PIC) simulation is the most important numerical tool in plasma physics. However, its long-term accuracy has not been established. To overcome this difficulty, we developed a canonical symplectic PIC method for the Vlasov-Maxwell system by discretising its canonical Poisson bracket. A fast local algorithm to solve the symplectic implicit time advance is discovered without root searching or global matrix inversion, enabling applications of the proposed method to very large-scale plasma simulations with many, e.g. 10(9), degrees of freedom. The long-term accuracy and fidelity of the algorithm enables us to numerically confirm Mouhot and Villani's theory and conjecture on nonlinearmore » Landau damping over several orders of magnitude using the PIC method, and to calculate the nonlinear evolution of the reflectivity during the mode conversion process from extraordinary waves to Bernstein waves.« less

Continuously differentiable PIC shape functions for triangular meshes

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

Barnes, D. C.

In this study, a new class of continuously-differentiable shape functions is developed and applied to two-dimensional electrostatic PIC simulation on an unstructured simplex (triangle) mesh. It is shown that troublesome aliasing instabilities are avoided for cold plasma simulation in which the Debye length is as small as 0.01 cell sizes. These new shape functions satisfy all requirements for PIC particle shape. They are non-negative, have compact support, and partition unity. They are given explicitly by cubic expressions in the usual triangle logical (areal) coordinates. The shape functions are not finite elements because their structure depends on the topology of themore » mesh, in particular, the number of triangles neighboring each mesh vertex. Nevertheless, they may be useful as approximations to solution of other problems in which continuity of derivatives is required or desired.« less

Effects of laser-plasma instabilities on hydro evolution in an OMEGA-EP long-scale-length experiment

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

Li, J.; Hu, S. X.; Ren, C.

Laser-plasma instabilities and hydro evolution of the coronal plasma in an OMEGA EP long-scale-length experiment with planar targets were studied with particle-in-cell (PIC) and hydrodynamic simulations. Plasma and laser conditions were first obtained in a two-dimensional DRACO hydro simulation with only inverse-bremsstrahlung absorption. Using these conditions, an OSIRIS PIC simulation was performed to study laser absorption and hot-electron generation caused by laser-plasma instabilities (LPIs) near the quarter-critical region. The obtained PIC information was subsequently coupled to another DRACO simulation to examine how the LPIs affect the overall hydrodynamics. Lastly, the results showed that the LPI-induced laser absorption increased the electronmore » temperature but did not significantly change the density scale length in the corona.« less

Study of plasma meniscus formation and beam halo in negative ion source using the 3D3VPIC model

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

Nishioka, S.; Goto, I.; Hatayama, A.

2015-04-08

In this paper, the effect of the electron confinement time on the plasma meniscus and the fraction of the beam halo is investigated by 3D3V-PIC (three dimension in real space and three dimension in velocity space) (Particle in Cell) simulation in the extraction region of negative ion source. The electron confinement time depends on the characteristic time of electron escape along the magnetic field as well as the characteristic time of diffusion across the magnetic field. Our 3D3V-PIC results support the previous result by 2D3V-PIC results i.e., it is confirmed that the penetration of the plasma meniscus becomes deep intomore » the source plasma region when the effective confinement time is short.« less

Development of an Implicit, Charge and Energy Conserving 2D Electromagnetic PIC Code on Advanced Architectures

NASA Astrophysics Data System (ADS)

Payne, Joshua; Taitano, William; Knoll, Dana; Liebs, Chris; Murthy, Karthik; Feltman, Nicolas; Wang, Yijie; McCarthy, Colleen; Cieren, Emanuel

2012-10-01

In order to solve problems such as the ion coalescence and slow MHD shocks fully kinetically we developed a fully implicit 2D energy and charge conserving electromagnetic PIC code, PlasmaApp2D. PlasmaApp2D differs from previous implicit PIC implementations in that it will utilize advanced architectures such as GPUs and shared memory CPU systems, with problems too large to fit into cache. PlasmaApp2D will be a hybrid CPU-GPU code developed primarily to run on the DARWIN cluster at LANL utilizing four 12-core AMD Opteron CPUs and two NVIDIA Tesla GPUs per node. MPI will be used for cross-node communication, OpenMP will be used for on-node parallelism, and CUDA will be used for the GPUs. Development progress and initial results will be presented.

Comparison of Hall Thruster Plume Expansion Model with Experimental Data

DTIC Science & Technology

2006-05-23

focus of this study, is a hybrid particle- in-cell ( PIC ) model that tracks particles along an unstructured tetrahedral mesh. * Research Engineer...measurements of the ion current density profile, ion energy distributions, and ion species fraction distributions using a nude Faraday probe, retarding...Vol.37 No.1. 6 Oh, D. and Hastings, D., “Three Dimensional PIC -DSMC Simulations of Hall Thruster Plumes and Analysis for Realistic Spacecraft

Verification of long wavelength electromagnetic modes with a gyrokinetic-fluid hybrid model in the XGC code

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

Hager, Robert; Lang, Jianying; Chang, C. S.

As an alternative option to kinetic electrons, the gyrokinetic total-f particle-in-cell (PIC) code XGC1 has been extended to the MHD/fluid type electromagnetic regime by combining gyrokinetic PIC ions with massless drift-fluid electrons. Here, two representative long wavelength modes, shear Alfven waves and resistive tearing modes, are verified in cylindrical and toroidal magnetic field geometries.

Verification of long wavelength electromagnetic modes with a gyrokinetic-fluid hybrid model in the XGC code

DOE PAGES

Hager, Robert; Lang, Jianying; Chang, C. S.; ...

2017-05-24

As an alternative option to kinetic electrons, the gyrokinetic total-f particle-in-cell (PIC) code XGC1 has been extended to the MHD/fluid type electromagnetic regime by combining gyrokinetic PIC ions with massless drift-fluid electrons. Here, two representative long wavelength modes, shear Alfven waves and resistive tearing modes, are verified in cylindrical and toroidal magnetic field geometries.

Radiation Test Results for Common CubeSat Microcontrollers and Microprocessors

NASA Technical Reports Server (NTRS)

Guertin, Steven M.; Amrbar, Mehran; Vartanian, Sergeh

2015-01-01

SEL, SEU, and TID results are presented for microcontrollers and microprocessors of interest for small satellite systems such as the TI MSP430F1611, MSP430F1612 and MSP430FR5739, Microchip PIC24F256GA110 and dsPIC33FJ256GP710, Atmel AT91SAM9G20, and Intel Atom E620T, and the Qualcomm Snapdragon APQ8064.

Adjuvant-Loaded Spiky Gold Nanoparticles for Activation of Innate Immune Cells.

PubMed

Nam, Jutaek; Son, Sejin; Moon, James J

2017-10-01

Gold nanoparticles are versatile carriers for delivery of biomacromolecules. Here, we have developed spiky gold nanoparticles (SGNPs) that can efficiently deliver immunostimulatory agents. Our goal was to develop a platform technology for co-delivery of multiple adjuvant molecules for synergistic stimulation and maturation of innate immune cells. SGNPs were synthesized by a seed-mediated, surfactant-free synthesis method and incorporated with polyinosinic-polycytidylic acid (pIC) and DNA oligonucleotide containing unmethylated CpG motif (CpG) by an electrostatic layer-by-layer approach. Adjuvant-loaded SGNP nano-complexes were examined for their biophysical and biochemical properties and studied for immune activation using bone marrow-derived dendritic cells (BMDCs). We have synthesized SGNPs with branched nano-spikes layered with pIC and/or CpG. Adjuvant-loaded SGNP nano-complexes promoted cellular uptake of the adjuvants. Importantly, we achieved spatio-temporal control over co-delivery of pIC and CpG via SGNPs, which produced synergistic enhancement in cytokine release (IL-6, TNF-α) and upregulation of co-stimulatory markers (CD40, CD80, CD86) in BMDCs, compared with pIC, CpG, or their admixtures. SGNPs serve as a versatile delivery platform that allows flexible and on-demand cargo fabrication for strong activation of innate immune cells.

Psychophysical studies of the performance of an image database retrieval system

NASA Astrophysics Data System (ADS)

Papathomas, Thomas V.; Conway, Tiffany E.; Cox, Ingemar J.; Ghosn, Joumana; Miller, Matt L.; Minka, Thomas P.; Yianilos, Peter N.

1998-07-01

We describe psychophysical experiments conducted to study PicHunter, a content-based image retrieval (CBIR) system. Experiment 1 studies the importance of using (a) semantic information, (2) memory of earlier input and (3) relative, rather than absolute, judgements of image similarity. The target testing paradigm is used in which a user must search for an image identical to a target. We find that the best performance comes from a version of PicHunter that uses only semantic cues, with memory and relative similarity judgements. Second best is use of both pictorial and semantic cues, with memory and relative similarity judgements. Most reports of CBIR systems provide only qualitative measures of performance based on how similar retrieved images are to a target. Experiment 2 puts PicHunter into this context with a more rigorous test. We first establish a baseline for our database by measuring the time required to find an image that is similar to a target when the images are presented in random order. Although PicHunter's performance is measurably better than this, the test is weak because even random presentation of images yields reasonably short search times. This casts doubt on the strength of results given in other reports where no baseline is established.

Quantitative Analysis of HIV-1 Preintegration Complexes

PubMed Central

Engelman, Alan; Oztop, Ilker; Vandegraaff, Nick; Raghavendra, Nidhanapati K.

2009-01-01

Retroviral replication proceeds through the formation of a provirus, an integrated DNA copy of the viral RNA genome. The linear cDNA product of reverse transcription is the integration substrate and two different integrase activities, 3′ processing and DNA strand transfer, are required for provirus formation. Integrase nicks the cDNA ends adjacent to phylogenetically-conserved CA dinucleotides during 3′ processing. After nuclear entry and locating a suitable chromatin acceptor site, integrase joins the recessed 3′-OHs to the 5′-phosphates of a double-stranded staggered cut in the DNA target. Integrase functions in the context of a large nucleoprotein complex, called the preintegration complex (PIC), and PICs are analyzed to determine levels of integrase 3′ processing and DNA strand transfer activities that occur during acute virus infection. Denatured cDNA end regions are monitored by indirect end-labeling to measure the extent of 3′ processing. Native PICs can efficiently integrate their viral cDNA into exogenously added target DNA in vitro, and Southern blotting or nested PCR assays are used to quantify the resultant DNA strand transfer activity. This study details HIV-1 infection, PIC extraction, partial purification, and quantitative analyses of integrase 3′ processing and DNA strand transfer activities. PMID:19233280

Hmo1 directs pre-initiation complex assembly to an appropriate site on its target gene promoters by masking a nucleosome-free region

PubMed Central

Kasahara, Koji; Ohyama, Yoshifumi; Kokubo, Tetsuro

2011-01-01

Saccharomyces cerevisiae Hmo1 binds to the promoters of ∼70% of ribosomal protein genes (RPGs) at high occupancy, but is observed at lower occupancy on the remaining RPG promoters. In Δhmo1 cells, the transcription start site (TSS) of the Hmo1-enriched RPS5 promoter shifted upstream, while the TSS of the Hmo1-limited RPL10 promoter did not shift. Analyses of chimeric RPS5/RPL10 promoters revealed a region between the RPS5 upstream activating sequence (UAS) and core promoter, termed the intervening region (IVR), responsible for strong Hmo1 binding and an upstream TSS shift in Δhmo1 cells. Chromatin immunoprecipitation analyses showed that the RPS5-IVR resides within a nucleosome-free region and that pre-initiation complex (PIC) assembly occurs at a site between the IVR and a nucleosome overlapping the TSS (+1 nucleosome). The PIC assembly site was shifted upstream in Δhmo1 cells on this promoter, indicating that Hmo1 normally masks the RPS5-IVR to prevent PIC assembly at inappropriate site(s). This novel mechanism ensures accurate transcriptional initiation by delineating the 5′- and 3′-boundaries of the PIC assembly zone. PMID:21288884

Multidimensional, fully implicit, exactly conserving electromagnetic particle-in-cell simulations

NASA Astrophysics Data System (ADS)

Chacon, Luis

2015-09-01

We discuss a new, conservative, fully implicit 2D-3V particle-in-cell algorithm for non-radiative, electromagnetic kinetic plasma simulations, based on the Vlasov-Darwin model. Unlike earlier linearly implicit PIC schemes and standard explicit PIC schemes, fully implicit PIC algorithms are unconditionally stable and allow exact discrete energy and charge conservation. This has been demonstrated in 1D electrostatic and electromagnetic contexts. In this study, we build on these recent algorithms to develop an implicit, orbit-averaged, time-space-centered finite difference scheme for the Darwin field and particle orbit equations for multiple species in multiple dimensions. The Vlasov-Darwin model is very attractive for PIC simulations because it avoids radiative noise issues in non-radiative electromagnetic regimes. The algorithm conserves global energy, local charge, and particle canonical-momentum exactly, even with grid packing. The nonlinear iteration is effectively accelerated with a fluid preconditioner, which allows efficient use of large timesteps, O(√{mi/me}c/veT) larger than the explicit CFL. In this presentation, we will introduce the main algorithmic components of the approach, and demonstrate the accuracy and efficiency properties of the algorithm with various numerical experiments in 1D and 2D. Support from the LANL LDRD program and the DOE-SC ASCR office.

Tough and Conductive Hybrid Hydrogels Enabling Facile Patterning.

PubMed

Zhu, Fengbo; Lin, Ji; Wu, Zi Liang; Qu, Shaoxing; Yin, Jun; Qian, Jin; Zheng, Qiang

2018-04-25

Conductive polymer hydrogels (CPHs) that combine the unique properties of hydrogels and electronic properties of conductors have shown their great potentials in wearable/implantable electronic devices, where materials with remarkable mechanical properties, high conductivity, and easy processability are demanding. Here, we have developed a new type of polyion complex/polyaniline (PIC/PAni) hybrid hydrogels that are tough, conductive, and can be facilely patterned. The incorporation of conductive phase (PAni) into PIC matrix through phytic acid resulted in hybrid gels with ∼65 wt % water; high conductivity while maintaining the key viscoelasticity of the tough matrix. The gel prepared from 1 M aniline (Ani) exhibited the breaking strain, fracture stress, tensile modulus, and electrical conductivity of 395%, 1.15 MPa, 5.31 MPa, and 0.7 S/m, respectively, superior to the most existing CPHs. The mechanical and electrical performance of PIC/PAni hybrid hydrogels exhibited pronounced rate-dependent and self-recovery behaviors. The hybrid gels can effectively detect subtle human motions as strain sensors. Alternating conductive/nonconductive patterns can be readily achieved by selective Ani polymerization using stencil masks. This facile patterning method based on PIC/PAni gels can be readily scaled up for fast fabrication of wavy gel circuits and multichannel sensor arrays, enabling real-time monitoring of the large-extent and large-area deformations with various sensitivities.

[Clinical study of iron protein succinylate oral solution for preventing and treating anemia of prematurity].

PubMed

Xing, Yan; Tong, Xiao-Mei

2013-12-01

To evaluate the efficacy and safety of iron protein succinylate (IPS) oral solution in preventing and treating anemia of prematurity (AOP). Sixty premature infants less than 35 weeks of gestation were randomly divided into IPS (n=30) and polysaccharide iron complex (PIC) groups(n=30). Treatment began at two weeks after birth. The infants received IPS or PIC in addition to recombinant human erythropoietin. On days 14, 28, 42, and 60 after treatment, hemoglobin (Hb), red blood cell count(RBC), hematocrit (HCT), percentage of reticulocytes, serum iron, and serum ferritin were determined. Liver and renal functions were evaluated before and after treatment. There were significant differences in the changing trends of RBC and HCT between the two groups (P<0.05). In the IPS group, RBC and HCT gradually decreased after birth, but began to rise gradually on days 28 and 42 of treatment; in the PIC group, RBC and HCT kept decreasing from birth to day 60 of treatment. On day 60 of treatment, the IPS group had significantly higher levels of Hb, RBC, HCT, serum iron, and serum ferritin than the PIC group (P<0.05). No notable adverse events occurred in either group. IPS oral solution has good efficacy and tolerability in preventing and treating AOP.

Bilateral Renal Denervation Ameliorates Isoproterenol-Induced Heart Failure through Downregulation of the Brain Renin-Angiotensin System and Inflammation in Rat

PubMed Central

Li, Jian-Dong; Cheng, Ai-Yuan; Huo, Yan-Li; Fan, Jie; Zhang, Yu-Ping; Fang, Zhi-Qin; Sun, Hong-Sheng; Peng, Wei; Zhang, Jin-Shun

2016-01-01

Heart failure (HF) is characterized by cardiac dysfunction along with autonomic unbalance that is associated with increased renin-angiotensin system (RAS) activity and elevated levels of proinflammatory cytokines (PICs). Renal denervation (RD) has been shown to improve cardiac function in HF, but the protective mechanisms remain unclear. The present study tested the hypothesis that RD ameliorates isoproterenol- (ISO-) induced HF through regulation of brain RAS and PICs. Chronic ISO infusion resulted in remarked decrease in blood pressure (BP) and increase in heart rate and cardiac dysfunction, which was accompanied by increased BP variability and decreased baroreflex sensitivity and HR variability. Most of these adverse effects of ISO on cardiac and autonomic function were reversed by RD. Furthermore, ISO upregulated mRNA and protein expressions of several components of the RAS and PICs in the lamina terminalis and hypothalamic paraventricular nucleus, two forebrain nuclei involved in cardiovascular regulations. RD significantly inhibited the upregulation of these genes. Either intracerebroventricular AT1-R antagonist, irbesartan, or TNF-α inhibitor, etanercept, mimicked the beneficial actions of RD in the ISO-induced HF. The results suggest that the RD restores autonomic balance and ameliorates ISO-induced HF and that the downregulated RAS and PICs in the brain contribute to these beneficial effects of RD. PMID:27746855

Landsat-7 ETM+ radiometric calibration status

USGS Publications Warehouse

Barsi, Julia A.; Markham, Brian L.; Czapla-Myers, J. S.; Helder, Dennis L.; Hook, Simon; Schott, John R.; Haque, Md. Obaidul

2016-01-01

Now in its 17th year of operation, the Enhanced Thematic Mapper + (ETM+), on board the Landsat-7 satellite, continues to systematically acquire imagery of the Earth to add to the 40+ year archive of Landsat data. Characterization of the ETM+ on-orbit radiometric performance has been on-going since its launch in 1999. The radiometric calibration of the reflective bands is still monitored using on-board calibration devices, though the Pseudo-Invariant Calibration Sites (PICS) method has proven to be an effective tool as well. The calibration gains were updated in April 2013 based primarily on PICS results, which corrected for a change of as much as -0.2%/year degradation in the worst case bands. A new comparison with the SADE database of PICS results indicates no additional degradation in the updated calibration. PICS data are still being tracked though the recent trends are not well understood. The thermal band calibration was updated last in October 2013 based on a continued calibration effort by NASA/Jet Propulsion Lab and Rochester Institute of Technology. The update accounted for a 0.036 W/m2 sr μm or 0.26K at 300K bias error. The updated lifetime trend is now stable to within +/- 0.4K.

Insulin mimesis of vanadium derivatives. Oxidation of cysteine by V(V) oxo diperoxo complexes.

PubMed

Ballistreri, F P; Barbuzzi, E G; Tomaselli, G A; Toscano, R M

2000-05-30

Kinetics of the oxidation of cysteine to cystine by four V(V) oxo diperoxo complexes [VO(O2)2L] possessing insulin mimetic activity, where L = oxalate(oxa), picolinate (pic), bipyridil (bipy), phenanthroline(phen), were performed in water at 10 degrees C by the UV or stopped-flow technique. 51V NMR spectra indicate that oxa undergoes a total ligand dissociation differently from pic, bipy and phen which hold their ligands also in solution. The observed reactivity is deeply affected by the identity of the ligand. The process seems to require coordination of the cysteine to the metal, followed by oxidation within the coordination sphere. In this respect phen and bipy make the coordination of cysteine much easier than oxa and pic. It is suggested, also on the basis of some preliminary observations concerning the oxidation of C6H5CH2SH, that the oxidation process is triggered by an electron transfer step. The rate of this step would be higher for oxa and pic than for phen and bipy. The observation that the oxidative ability of these vanadium peroxo complexes is dependent upon the nature of the ligands might match the analogous finding that their insulin mimetic activity is also modulated by the ligand identities.

Mediator independently orchestrates multiple steps of preinitiation complex assembly in vivo

PubMed Central

Eyboulet, Fanny; Wydau-Dematteis, Sandra; Eychenne, Thomas; Alibert, Olivier; Neil, Helen; Boschiero, Claire; Nevers, Marie-Claire; Volland, Hervé; Cornu, David; Redeker, Virginie; Werner, Michel; Soutourina, Julie

2015-01-01

Mediator is a large multiprotein complex conserved in all eukaryotes, which has a crucial coregulator function in transcription by RNA polymerase II (Pol II). However, the molecular mechanisms of its action in vivo remain to be understood. Med17 is an essential and central component of the Mediator head module. In this work, we utilised our large collection of conditional temperature-sensitive med17 mutants to investigate Mediator's role in coordinating preinitiation complex (PIC) formation in vivo at the genome level after a transfer to a non-permissive temperature for 45 minutes. The effect of a yeast mutation proposed to be equivalent to the human Med17-L371P responsible for infantile cerebral atrophy was also analyzed. The ChIP-seq results demonstrate that med17 mutations differentially affected the global presence of several PIC components including Mediator, TBP, TFIIH modules and Pol II. Our data show that Mediator stabilizes TFIIK kinase and TFIIH core modules independently, suggesting that the recruitment or the stability of TFIIH modules is regulated independently on yeast genome. We demonstrate that Mediator selectively contributes to TBP recruitment or stabilization to chromatin. This study provides an extensive genome-wide view of Mediator's role in PIC formation, suggesting that Mediator coordinates multiple steps of a PIC assembly pathway. PMID:26240385

Incidence of phlebitis associated with the use of peripheral IV catheter and following catheter removal

PubMed Central

Urbanetto, Janete de Souza; Peixoto, Cibelle Grassmann; May, Tássia Amanda

2016-01-01

ABSTRACT Objective: to investigate the incidence of phlebitis and its association with risk factors when using peripheral IV catheters (PIC) and following their removal - (post-infusion phlebitis) in hospitalized adults. Method: a cohort study of 171 patients using PIC, totaling 361 punctures. Sociodemographic variables and variables associated with the catheter were collected. Descriptive and analytical statistical analyses were performed. Results: average patient age was 56.96 and 51.5% of the sample population was male. The incidence of phlebitis was 1.25% while using PIC, and 1.38% post-infusion. The incidence of phlebitis while using PIC was associated with the length of time the catheter remained in place, whereas post-infusion phlebitis was associated with puncture in the forearm. Ceftriaxone, Clarithromycin and Oxacillin are associated with post-infusion phlebitis. Conclusions: this study made it possible to investigate the association between risk factors and phlebitis during catheter use and following its removal. The frequency of post-infusion phlebitis was larger than the incidence of phlebitis with the catheter in place, with Phlebitis Grade III and II being the most frequently found in each of these situations, respectively. Aspects related to post-infusion phlebitis can be explained, given the limited number of studies addressing this theme from this perspective. PMID:27508916

Anomalous electron transport in Hall-effect thrusters: Comparison between quasi-linear kinetic theory and particle-in-cell simulations

NASA Astrophysics Data System (ADS)

Lafleur, T.; Martorelli, R.; Chabert, P.; Bourdon, A.

2018-06-01

Kinetic drift instabilities have been implicated as a possible mechanism leading to anomalous electron cross-field transport in E × B discharges, such as Hall-effect thrusters. Such instabilities, which are driven by the large disparity in electron and ion drift velocities, present a significant challenge to modelling efforts without resorting to time-consuming particle-in-cell (PIC) simulations. Here, we test aspects of quasi-linear kinetic theory with 2D PIC simulations with the aim of developing a self-consistent treatment of these instabilities. The specific quantities of interest are the instability growth rate (which determines the spatial and temporal evolution of the instability amplitude), and the instability-enhanced electron-ion friction force (which leads to "anomalous" electron transport). By using the self-consistently obtained electron distribution functions from the PIC simulations (which are in general non-Maxwellian), we find that the predictions of the quasi-linear kinetic theory are in good agreement with the simulation results. By contrast, the use of Maxwellian distributions leads to a growth rate and electron-ion friction force that is around 2-4 times higher, and consequently significantly overestimates the electron transport. A possible method for self-consistently modelling the distribution functions without requiring PIC simulations is discussed.

Rapamycin treatment benefits glucose metabolism in mouse models of type 2 diabetes.

PubMed

Reifsnyder, Peter C; Flurkey, Kevin; Te, Austen; Harrison, David E

2016-11-30

Numerous studies suggest that rapamycin treatment promotes insulin resistance, implying that rapamycin could have negative effects on patients with, or at risk for, type 2 diabetes (T2D). New evidence, however, indicates that rapamycin treatment produces some benefits to energy metabolism, even in the context of T2D. Here, we survey 5 mouse models of T2D (KK, KK-Ay, NONcNZO10, BKS- db/db , TALLYHO) to quantify effects of rapamycin on well-recognized markers of glucose homeostasis within a wide range of T2D environments. Interestingly, dietary rapamycin treatment did not exacerbate impaired glucose or insulin tolerance, or elevate circulating lipids as T2D progressed. In fact, rapamycin increased insulin sensitivity and reduced weight gain in 3 models, and decreased hyperinsulinemia in 2 models. A key covariate of this genetically-based, differential response was pancreatic insulin content (PIC): Models with low PIC exhibited more beneficial effects than models with high PIC. However, a minimal PIC threshold may exist, below which hypoinsulinemic hyperglycemia develops, as it did in TALLYHO. Our results, along with other studies, indicate that beneficial or detrimental metabolic effects of rapamycin treatment, in a diabetic or pre-diabetic context, are driven by the interaction of rapamycin with the individual model's pancreatic physiology.

Solar UV irradiances modulate effects of ocean acidification on the coccolithophorid Emiliania huxleyi.

PubMed

Xu, Kai; Gao, Kunshan

2015-01-01

Emiliania huxleyi, the most abundant coccolithophorid in the oceans, is naturally exposed to solar UV radiation (UVR, 280-400 nm) in addition to photosynthetically active radiation (PAR). We investigated the physiological responses of E. huxleyi to the present day and elevated CO2 (390 vs 1000 μatm; with pH(NBS) 8.20 vs 7.86) under indoor constant PAR and fluctuating solar radiation with or without UVR. Enrichment of CO2 stimulated the production rate of particulate organic carbon (POC) under constant PAR, but led to unchanged POC production under incident fluctuating solar radiation. The production rates of particulate inorganic carbon (PIC) as well as PIC/POC ratios were reduced under the elevated CO2, ocean acidification (OA) condition, regardless of PAR levels, and the presence of UVR. However, moderate levels of UVR increased PIC production rates and PIC/POC ratios. OA treatment interacted with UVR to influence the alga's physiological performance, leading to reduced specific growth rate in the presence of UVA (315-400 nm) and decreased quantum yield, along with enhanced nonphotochemical quenching, with addition of UVB (280-315 nm). The results clearly indicate that UV radiation needs to be invoked as a key stressor when considering the impacts of ocean acidification on E. huxleyi. © 2014 The American Society of Photobiology.

The plasma physics of thermal conduction in the intracluster medium of galaxy clusters

NASA Astrophysics Data System (ADS)

Reynolds, Christopher

Most of the baryons in a galaxy cluster reside in a hot (10-100 million K) and tenuous gaseous atmosphere confined by the gravitational potential of the cluster's dark matter halo. Understanding the microphysics of this intracluster medium (ICM), particularly the transport processes such as thermal conduction and viscosity, is important to any understanding of the thermodynamic state of ICM atmospheres. For example, the current paradigm is that radiative losses in the ICM core are offset by energy from a central jetted active galactic nucleus (AGN), preventing a cooling catastrophe in the cluster core. However, the mechanism by which the jet-injected energy is thermalized in the ICM is highly uncertain - the dissipation of waves or turbulence by thermal conduction or plasma viscosity is a leading contender. A knowledge of thermal conduction in the ICM is also important for any attempts to understand the global temperature profiles of clusters, with consequences for e.g. cosmological studies based on observations of the SunyaevZeldovich (SZ) effect. The basic physics of thermal conduction in the ICM is very poorly understood, however, leading to a huge uncertainty in the relevant coefficients. The ICM resides in a poorly studied regime of plasma physics - it is a highly magnetized (gyroradii << particle mean free path), high-beta (thermal pressure >> magnetic pressure), and weakly collisional (mean-free path only moderately less than global scale lengths) plasma. Thermal conduction will be strongly suppressed perpendicular to magnetic fields lines. But even along field lines, the growth of small scale and fast kinetic instabilities may strongly suppress thermal conduction. Hence the usual assumption, that conduction along the field has its classical Spitzer value, has a shaky theoretical basis and may well be wildly inaccurate. In this proposal, we use analytical theory and computer models to explore thermal conduction in ICM-like plasmas. Recently, we have found that a strong heat-flux will drive a powerful whistler-wave instability and, provided we treat the problem in more than 1D so that oblique modes are captured, these waves efficiently scatter electrons thereby shutting down the heat-flux. Our proposed work builds on these findings with the goal of characterizing the macroscopic effective thermal conduction in a form that can be included in fluid (magnetohydrodynamic; MHD) models of the ICM. We will, 1) Conduct an extended linear analysis of the heat-flux whistler instability, exploring the interaction of the heat flux and the pressure anisotropies that would result from bulk motions of the ICM. We will map the stable/unstable regions as a function of heat-flux, pressure anisotropy, and plasma-beta. 2) Perform particle-in-cell (PIC) simulations to explore the non-linear saturation of the heat-flux whistler instability as a function of the plasma-beta and heat-flux, extending the current work (i.e. very strong fluxes) down to the modest heat-fluxes found in the real ICM. Key is whether overlapping wave-particle resonances that are so efficient at killing the conduction with strong heat-fluxes still operate when the driving heat-flux is weak. 3) Develop a new computational/PIC model that, in contrast to current work, sustains a temperature gradient across the domain thereby allowing us to directly measure the relationship between temperature gradient and heat flux. 4) Build a new thermal conduction model, allowing the heat flux to have a non-linear dependence on temperature gradient, and plasma-beta. We will develop thermal conduction algorithms that can be used in public MHD e.g., PLUTO or FLASH. This work will provide the crucial bridge between the global/MHD models of ICM atmospheres and the microphysics that dictates the transport processes. It will inform the next generation of cluster models used to interpret data from NASA's fleet of X-ray observatories.

Peculiarities of both light and beta-particles scattering by ultrathin diamond-like semiconductor film.

PubMed

Rumyantsev, Vladimir V; Shtaerman, Esfir Y

2008-02-01

Peculiarities of scattering of TM-polarized light wave by a diamond-like crystalline nano-layer are studied. They are due to specific dispersion of n-phonon polaritons localized in the layer. The IR polaritons discussed here (relating to diamond and Si crystals which are nonpolar materials) will only appear if some of the vibration modes become polar, e.g., due to the presence of the surface. As a result of mixing of g- and u-modes of ion oscillations along the (111)-direction in the near-surface layer, it is possible to observe additional (with respect to bulk) scattering of coherent electromagnetic waves of the Stokes and anti-Stokes frequencies. beta-particles can be utilized as an independent tool of study of new semiconductors, in particular thin diamond films. The effect associated with response of a quasi-two-dimensional diamond-like layer to the moving electron field is considered. beta-particle field induces phonon excitation modes to arise in the material. Coupled with the beta-particle electromagnetic modes they generate polaritons. Spectral density of the radiation intensity of the flashed phonon polaritons has been estimated as a function of the layer thickness as well as of the scattering angle and the beta-particle velocity.

Immunomodulatory Factors Galectin-9 and Interferon-Gamma Synergize to Induce Expression of Rate-Limiting Enzymes of the Kynurenine Pathway in the Mouse Hippocampus

PubMed Central

Brooks, Alexandra K.; Lawson, Marcus A.; Rytych, Jennifer L.; Yu, Kevin C.; Janda, Tiffany M.; Steelman, Andrew J.; McCusker, Robert H.

2016-01-01

Elevated levels of circulating pro-inflammatory cytokines are associated with symptomology of several psychiatric disorders, notably major depressive disorder. Symptomology has been linked to inflammation/cytokine-dependent induction of the Kynurenine Pathway. Galectins, like pro-inflammatory cytokines, play a role in neuroinflammation and the pathogenesis of several neurological disorders but without a clearly defined mechanism of action. Their involvement in the Kynurenine Pathway has not been investigated. Thus, we searched for a link between galectins and the Kynurenine Pathway using in vivo and ex vivo models. Mice were administered LPS and pI:C to determine if galectins (Gal’s) were upregulated in the brain following in vivo inflammatory challenges. We then used organotypic hippocampal slice cultures (OHSCs) to determine if Gal’s, alone or with inflammatory mediators [interferon-gamma (IFNγ), tumor necrosis factor-alpha (TNFα), interleukin-1beta (IL-1β), polyinosine-polycytidylic acid (pI:C), and dexamethasone (Dex; synthetic glucocorticoid)], would increase expression of indoleamine/tryptophan-2,3-dioxygenases (DO’s: Ido1, Ido2, and Tdo2; Kynurenine Pathway rate-limiting enzymes). In vivo, hippocampal expression of cytokines (IL-1β, TNFα, and IFNγ), Gal-3, and Gal-9 along with Ido1 and Ido2 were increased by LPS and pI:C (bacterial and viral mimetics). Of the cytokines induced in vivo, only IFNγ increased expression of two Ido1 transcripts (Ido1-FL and Ido1-v1) by OHSCs. Although ineffective alone, Gal-9 accentuated IFNγ-induced expression of only Ido1-FL. Similarly, IFNγ induced expression of several Ido2 transcripts (Ido2-v1, Ido2-v3, Ido2-v4, Ido2-v5, and Ido2-v6). Gal-9 accentuated IFNγ-induced expression of only Ido2-v1. Surprisingly, Gal-9 alone, slightly but significantly, induced expression of Tdo2 (Tdo2-v1 and Tdo2-v2, but not Tdo2-FL). These effects were specific to Gal-9 as Gal-1 and Gal-3 did not alter DO expression. These results are the first to show that brain Gal-9 is increased during LPS- and pI:C-induced neuroinflammation. Increased expression of Gal-9 may be critical for neuroinflammation-dependent induction of DO expression, either acting alone (Tdo2-v1 and Tdo2-v2) or to enhance IFNγ activity (Ido1-FL and Ido2-v1). Although these novel actions of Gal-9 are described for hippocampus, they have the potential to operate as DO-dependent immunomodulatory processes outside the brain. With the expanding implications of Kynurenine Pathway activation across multiple immune and psychiatric disorders, this synergy provides a new target for therapeutic development. PMID:27799931

Electron hole tracking PIC simulation

NASA Astrophysics Data System (ADS)

Zhou, Chuteng; Hutchinson, Ian

2016-10-01

An electron hole is a coherent BGK mode solitary wave. Electron holes are observed to travel at high velocities relative to bulk plasmas. The kinematics of a 1-D electron hole is studied using a novel Particle-In-Cell simulation code with fully kinetic ions. A hole tracking technique enables us to follow the trajectory of a fast-moving solitary hole and study quantitatively hole acceleration and coupling to ions. The electron hole signal is detected and the simulation domain moves by a carefully designed feedback control law to follow its propagation. This approach has the advantage that the length of the simulation domain can be significantly reduced to several times the hole width, which makes high resolution simulations tractable. We observe a transient at the initial stage of hole formation when the hole accelerates to several times the cold-ion sound speed. Artificially imposing slow ion speed changes on a fully formed hole causes its velocity to change even when the ion stream speed in the hole frame greatly exceeds the ion thermal speed, so there are no reflected ions. The behavior that we observe in numerical simulations agrees very well with our analytic theory of hole momentum conservation and energization effects we call ``jetting''. The work was partially supported by the NSF/DOE Basic Plasma Science Partnership under Grant DE-SC0010491. Computer simulations were carried out on the MIT PSFC parallel AMD Opteron/Infiniband cluster Loki.

The influence of moving with music on motor cortical activity.

PubMed

Stegemöller, Elizabeth L; Izbicki, Patricia; Hibbing, Paul

2018-06-19

Although there is a growing interest in using music to improve movement performance in various populations, there remains a need to better understand how music influences motor cortical activity. Listening to music is tightly linked to neural processes within the motor cortex and can modulate motor cortical activity in healthy young adult (HYAs). There is limited evidence regarding how moving to music modulates motor cortical activity. Thus, the purpose of this study was to explore the influence of moving to music on motor cortical activity in HYAs. Electroencephalography was collected while 32 HYAs tapped their index finger in time with a tone and with two contrasting music styles. Two movement rates were presented for each condition. Power spectra were obtained from data collected over the primary sensorimotor region and supplemental motor area and were compared between conditions. Results revealed a significant difference between both music conditions and the tone only condition for both the regions. For both music styles, power was increased in the beta band for low movement rates and increased in the alpha band for high movement rates. A secondary analysis determining the effect of music experience on motor cortical activity revealed a significant difference between musicians and non-musicians. Power in the beta band was increased across all conditions. The results of this study provide the initial step towards a more complete understanding of the neurophysiological underpinnings of music on movement performance which may inform future studies and therapeutic strategies. Copyright © 2018 Elsevier B.V. All rights reserved.

Design and Control of Omnidirectional Unmanned Ground Vehicles for Rough Terrain

DTIC Science & Technology

2012-08-29

company, Quantum Signal. This rigid body dynamics simulation, housed within the Autonomous Navigation and Virtual Environment Laboratory (ANVEL) software...72 Figure 22: PIC main code. Page 24 of 72 Figure 23: PIC interrupt code. 3.3 Central Body Embedded Electronics As described above...located on the main body of the vehicle. This section describes how the on-board electronics works. The outline of the code is presented as is how

Comparison of Hall Thruster Plume Expansion Model with Experimental Data (Preprint)

DTIC Science & Technology

2006-07-01

Cartesian mesh. AQUILA, the focus of this study, is a hybrid PIC model that tracks particles along an unstructured tetrahedral mesh. COLISEUM is capable...measurements of the ion current density profile, ion energy distributions, and ion species fraction distributions using a nude Faraday probe...Spacecraft and Rockets, Vol.37 No.1. 6 Oh, D. and Hastings, D., “Three Dimensional PIC -DSMC Simulations of Hall Thruster Plumes and Analysis for

Conformal Electromagnetic Particle in Cell: A Review

DOE PAGES

Meierbachtol, Collin S.; Greenwood, Andrew D.; Verboncoeur, John P.; ...

2015-10-26

We review conformal (or body-fitted) electromagnetic particle-in-cell (EM-PIC) numerical solution schemes. Included is a chronological history of relevant particle physics algorithms often employed in these conformal simulations. We also provide brief mathematical descriptions of particle-tracking algorithms and current weighting schemes, along with a brief summary of major time-dependent electromagnetic solution methods. Several research areas are also highlighted for recommended future development of new conformal EM-PIC methods.

Four new species of Fissocantharis Pic, 1921 (Coleoptera, Cantharidae) from China

PubMed Central

Yang, Yuxia; Qi, Yaqing; Yang, Xingke

2018-01-01

Abstract Four new species of Fissocantharis Pic, 1921 are described: F. securiclata sp. n. (China: Zhejiang, Anhui), F. maculicollis sp. n. (China: Zhejiang), F. hainana sp. n. (China: Hainan) and F. laticollis sp. n. (China: Hainan), which are illustrated with the habitus and aedeagus of the male, the abdominal sternite VIII and the internal genitalia of the female. A key to the species from southeast China is provided. PMID:29670425

Pacific Northwest National Laboratory Potential Impact Categories for Radiological Air Emission Monitoring

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

Ballinger, Marcel Y.; Gervais, Todd L.; Barnett, J. Matthew

2012-06-05

In 2002, the EPA amended 40 CFR 61 Subpart H and 40 CFR 61 Appendix B Method 114 to include requirements from ANSI/HPS N13.1-1999 Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stack and Ducts of Nuclear Facilities for major emission points. Additionally, the WDOH amended the Washington Administrative Code (WAC) 246-247 Radiation protection-air emissions to include ANSI/HPS N13.1-1999 requirements for major and minor emission points when new permitting actions are approved. A result of the amended regulations is the requirement to prepare a written technical basis for the radiological air emission sampling and monitoring program. A keymore » component of the technical basis is the Potential Impact Category (PIC) assigned to an emission point. This paper discusses the PIC assignments for the Pacific Northwest National Laboratory (PNNL) Integrated Laboratory emission units; this revision includes five PIC categories.« less

A revision of the genus Pseudoechthistatus Pic (Coleoptera, Cerambycidae, Lamiinae, Lamiini)

PubMed Central

Bi, Wen-Xuan; Lin, Mei-Ying

2016-01-01

Abstract The genus Pseudoechthistatus Pic, 1917 is redefined and revised. Five species of the genus are described as new, Pseudoechthistatus sinicus sp. n. and Pseudoechthistatus chiangshunani sp. n. from central Yunnan, China, Pseudoechthistatus pufujiae sp. n. from western Yunnan, China, and Pseudoechthistatus holzschuhi sp. n. and Pseudoechthistatus glabripennis sp. n. from southern Yunnan and northern Vietnam. Pseudoechthistatus birmanicus Breuning, 1942 is excluded from the fauna of China. Three poorly known species, Pseudoechthistatus obliquefasciatus Pic, 1917, Pseudoechthistatus granulatus Breuning, 1942, and Pseudoechthistatus acutipennis Chiang, 1981 are redescribed, and the type localities of the former two species are discussed. Endophallic structure of seven species in inflated and everted condition are studied and compared with their relatives. Illustrations of habitus and major diagnostic features of all species are provided. Some biological notes are reported. An identification key as well as a distributional map are presented. PMID:27551207

A multi-dimensional nonlinearly implicit, electromagnetic Vlasov-Darwin particle-in-cell (PIC) algorithm

NASA Astrophysics Data System (ADS)

Chen, Guangye; Chacón, Luis; CoCoMans Team

2014-10-01

For decades, the Vlasov-Darwin model has been recognized to be attractive for PIC simulations (to avoid radiative noise issues) in non-radiative electromagnetic regimes. However, the Darwin model results in elliptic field equations that renders explicit time integration unconditionally unstable. Improving on linearly implicit schemes, fully implicit PIC algorithms for both electrostatic and electromagnetic regimes, with exact discrete energy and charge conservation properties, have been recently developed in 1D. This study builds on these recent algorithms to develop an implicit, orbit-averaged, time-space-centered finite difference scheme for the particle-field equations in multiple dimensions. The algorithm conserves energy, charge, and canonical-momentum exactly, even with grid packing. A simple fluid preconditioner allows efficient use of large timesteps, O (√{mi/me}c/veT) larger than the explicit CFL. We demonstrate the accuracy and efficiency properties of the of the algorithm with various numerical experiments in 2D3V.

Decreased calcification in the Southern Ocean over the satellite record

NASA Astrophysics Data System (ADS)

Freeman, Natalie M.; Lovenduski, Nicole S.

2015-03-01

Widespread ocean acidification is occurring as the ocean absorbs anthropogenic carbon dioxide from the atmosphere, threatening marine ecosystems, particularly the calcifying plankton that provide the base of the marine food chain and play a key role within the global carbon cycle. We use satellite estimates of particulate inorganic carbon (PIC), surface chlorophyll, and sea surface temperature to provide a first estimate of changing calcification rates throughout the Southern Ocean. From 1998 to 2014 we observe a 4% basin-wide reduction in summer calcification, with ˜9% reductions in large regions (˜1 × 106 km2) of the Pacific and Indian sectors. Southern Ocean trends are spatially heterogeneous and primarily driven by changes in PIC concentration (suspended calcite), which has declined by ˜24% in these regions. The observed decline in Southern Ocean calcification and PIC is suggestive of large-scale changes in the carbon cycle and provides insight into organism vulnerability in a changing environment.

The genus Scaphidium Olivier in East China (Coleoptera, Staphylinidae, Scaphidiinae)

PubMed Central

Tang, Liang; Li, Li-Zhen; He, Wen-Jia

2014-01-01

Abstract A review of 21 species of Scaphidium Olivier from East China is presented, including 6 new species: S. jinmingi sp. n. (Zhejiang, Anhui, Chongqing), S. crypticum sp. n. (Zhejiang, Fujian, Jiangxi, Guangxi), S. varifasciatum sp. n. (Zhejiang, An’hui), S. robustum sp. n. (Fujian, Guizhou, Chongqing, Guangxi, Yunnan), S. connexum sp. n. (Zhejiang, Fujian, Guangxi), and S. bayibini sp. n. (An’hui). New province records for S. comes Löbl, S. grande Gestro, S. sauteri Miwa & Mitono, S. formosanum Pic, S. carinense Achard, S. sinense Pic, S. delatouchei Achard, S. biwenxuani He, Tang & Li, S. klapperichi Pic, S. stigmatinotum Löbl, S. wuyongxiangi He, Tang & Li, and S. direptum Tang & Li as well as some biological notes are reported. Habitus and diagnostic characters of all species are photographed and a key to Scaphidium species of East China is provided. PMID:24843266

Efficient Modeling of Laser-Plasma Accelerators with INF and RNO

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

Benedetti, C.; Schroeder, C. B.; Esarey, E.

2010-11-04

The numerical modeling code INF and RNO (INtegrated Fluid and paRticle simulatioN cOde, pronounced 'inferno') is presented. INF and RNO is an efficient 2D cylindrical code to model the interaction of a short laser pulse with an underdense plasma. The code is based on an envelope model for the laser while either a PIC or a fluid description can be used for the plasma. The effect of the laser pulse on the plasma is modeled with the time-averaged poderomotive force. These and other features allow for a speedup of 2-4 orders of magnitude compared to standard full PIC simulations whilemore » still retaining physical fidelity. The code has been benchmarked against analytical solutions and 3D PIC simulations and here a set of validation tests together with a discussion of the performances are presented.« less