Science.gov

Sample records for neutron-gamma fields specific

  1. Dosimetry in mixed neutron-gamma fields

    SciTech Connect

    Remec, I.

    1998-04-01

    The gamma field accompanying neutrons may, in certain circumstances, play an important role in the analysis of neutron dosimetry and even in the interpretation of radiation induced steel embrittlement. At the High Flux Isotope Reactor pressure vessel the gamma induced reactions dominate the responses of {sup 237}Np and {sup 238}U dosimeters, and {sup 9}Be helium accumulation fluence monitors. The gamma induced atom displacement rate in steel is higher than corresponding neutron rate, and is the cause of ``accelerated embrittlement`` of HFIR materials. In a large body of water, adjacent to a fission plate, photofissions contribute significantly to the responses of fission monitors and need to be taken into account if the measurements are used for the qualification of the transport codes and cross-section libraries.

  2. Determination of the gamma-ray spectrum in a strong neutron/gamma-ray mixed field

    NASA Astrophysics Data System (ADS)

    Liu, Yuan-Hao; Lin, Yi-Chun; Nievaart, Sander; Chou, Wen-Tsae; Liu, Hong-Ming; Jiang, Shiang-Huei

    2011-10-01

    The knowledge of gamma-ray spectrum highly affects the accuracy of the correspondingly derived gamma-ray dose and the correctness of calculated neutron dose in the neutron/gamma-ray mixed field dosimetry when using the paired ionization chambers technique. It is of our interest to develop a method to determine the gamma-ray spectrum in a strong neutron/gamma-ray mixed field. The current type detector, Mg(Ar) ionization chamber with 6 different thick caps incorporated with the unfolding technique, was used to determine the gamma-ray spectrum in the THOR epithermal neutron beam, which contains intense neutrons and gamma rays. The applied caps had nominal thicknesses from 1 to 6 mm. Detector response functions of the applied Mg(Ar) chamber with different caps were calculated using MCNP5 with a validated chamber model. The spectrum unfolding process was performed using the well-known SAND-II algorithm. The unfolded result was found much softer than the originally calculated spectrum at the design stage. A large portion of low energy continuum was shown in the adjusted spectrum. This work gave us a much deeper insight into the THOR epithermal neutron beam and also showed a way to determine the gamma-ray spectrum.

  3. ESR response of CFQ-Gd2O3 dosimeters to a mixed neutron-gamma field: Monte Carlo simulation.

    PubMed

    Hoseininaveh, M; Ranjbar, A H

    2015-11-01

    Clear fused quartz (CFQ) may be considered a suitable material for electron and gamma dose measurements using electron spin resonance (ESR) technique. Research has been ongoing to optimize the neutron capture therapy (NCT) mechanism and its effects in cancer treatment. Neutron sources of the mixed neutron-gamma field are a challenge for this treatment method. A reliable dosimetric measurement and treatment should be able to determine various components of this mixed field. In this study, the ESR response of cylindrical and spherical shells of CFQ dosimeters, filled with Gd2O3, when exposed to a thermal neutron beam, has been investigated using Monte Carlo simulation. In order to maximize the ESR response, the dimensions of the outer and inner parts of the samples have been chosen as variables, and the amount of energy deposited in the samples has been determined. The optimum size of the samples has been determined, and the capability of discriminating gamma and neutron dose in a mixed neutron-gamma field regarding the CFQ-Gd2O3 dosimeter has also been widely studied. PMID:26342935

  4. Plasma driven neutron/gamma generator

    DOEpatents

    Leung, Ka-Ngo; Antolak, Arlyn

    2015-03-03

    An apparatus for the generation of neutron/gamma rays is described including a chamber which defines an ion source, said apparatus including an RF antenna positioned outside of or within the chamber. Positioned within the chamber is a target material. One or more sets of confining magnets are also provided to create a cross B magnetic field directly above the target. To generate neutrons/gamma rays, the appropriate source gas is first introduced into the chamber, the RF antenna energized and a plasma formed. A series of high voltage pulses are then applied to the target. A plasma sheath, which serves as an accelerating gap, is formed upon application of the high voltage pulse to the target. Depending upon the selected combination of source gas and target material, either neutrons or gamma rays are generated, which may be used for cargo inspection, and the like.

  5. Pulse-shape discrimination of the new plastic scintillators in neutron-gamma mixed field using fast digitizer card

    NASA Astrophysics Data System (ADS)

    Jančář, A.; Kopecký, Z.; Dressler, J.; Veškrna, M.; Matěj, Z.; Granja, C.; Solar, M.

    2015-11-01

    Recently invented plastic scintillator EJ-299-33 enables pulse-shape discrimination (PSD) and thus measurement of neutron and photon spectra in mixed fields. In this work we compare the PSD properties of EJ-299-33 plastic and the well-known NE-213 liquid scintillator in monoenergetic neutron fields generated by the Van de Graaff accelerator using the 3H(d, n)4He reaction. Pulses from the scintillators are processed by a newly developed digital measuring system employing the fast digitizer card. This card contains two AD converters connected to the measuring computer via 10 Gbps optical ethernet. The converters operate with a resolution of 12 bits and have two differential inputs with a sampling frequency 1 GHz. The resulting digital channels with different gains are merged into one composite channel with a higher digital resolution in a wide dynamic range of energies. Neutron signals are fully discriminated from gamma signals. Results are presented.

  6. Dose calculation in biological samples in a mixed neutron-gamma field at the TRIGA reactor of the University of Mainz.

    PubMed

    Schmitz, Tobias; Blaickner, Matthias; Schütz, Christian; Wiehl, Norbert; Kratz, Jens V; Bassler, Niels; Holzscheiter, Michael H; Palmans, Hugo; Sharpe, Peter; Otto, Gerd; Hampel, Gabriele

    2010-10-01

    To establish Boron Neutron Capture Therapy (BNCT) for non-resectable liver metastases and for in vitro experiments at the TRIGA Mark II reactor at the University of Mainz, Germany, it is necessary to have a reliable dose monitoring system. The in vitro experiments are used to determine the relative biological effectiveness (RBE) of liver and cancer cells in our mixed neutron and gamma field. We work with alanine detectors in combination with Monte Carlo simulations, where we can measure and characterize the dose. To verify our calculations we perform neutron flux measurements using gold foil activation and pin-diodes. Material and methods. When L-α-alanine is irradiated with ionizing radiation, it forms a stable radical which can be detected by electron spin resonance (ESR) spectroscopy. The value of the ESR signal correlates to the amount of absorbed dose. The dose for each pellet is calculated using FLUKA, a multipurpose Monte Carlo transport code. The pin-diode is augmented by a lithium fluoride foil. This foil converts the neutrons into alpha and tritium particles which are products of the (7)Li(n,α)(3)H-reaction. These particles are detected by the diode and their amount correlates to the neutron fluence directly. Results and discussion. Gold foil activation and the pin-diode are reliable fluence measurement systems for the TRIGA reactor, Mainz. Alanine dosimetry of the photon field and charged particle field from secondary reactions can in principle be carried out in combination with MC-calculations for mixed radiation fields and the Hansen & Olsen alanine detector response model. With the acquired data about the background dose and charged particle spectrum, and with the acquired information of the neutron flux, we are capable of calculating the dose to the tissue. Conclusion. Monte Carlo simulation of the mixed neutron and gamma field of the TRIGA Mainz is possible in order to characterize the neutron behavior in the thermal column. Currently we also

  7. The neutron-gamma Feynman variance to mean approach: Gamma detection and total neutron-gamma detection (theory and practice)

    NASA Astrophysics Data System (ADS)

    Chernikova, Dina; Axell, Kåre; Avdic, Senada; Pázsit, Imre; Nordlund, Anders; Allard, Stefan

    2015-05-01

    Two versions of the neutron-gamma variance to mean (Feynman-alpha method or Feynman-Y function) formula for either gamma detection only or total neutron-gamma detection, respectively, are derived and compared in this paper. The new formulas have particular importance for detectors of either gamma photons or detectors sensitive to both neutron and gamma radiation. If applied to a plastic or liquid scintillation detector, the total neutron-gamma detection Feynman-Y expression corresponds to a situation where no discrimination is made between neutrons and gamma particles. The gamma variance to mean formulas are useful when a detector of only gamma radiation is used or when working with a combined neutron-gamma detector at high count rates. The theoretical derivation is based on the Chapman-Kolmogorov equation with the inclusion of general reactions and corresponding intensities for neutrons and gammas, but with the inclusion of prompt reactions only. A one energy group approximation is considered. The comparison of the two different theories is made by using reaction intensities obtained in MCNPX simulations with a simplified geometry for two scintillation detectors and a 252Cf-source. In addition, the variance to mean ratios, neutron, gamma and total neutron-gamma are evaluated experimentally for a weak 252Cf neutron-gamma source, a 137Cs random gamma source and a 22Na correlated gamma source. Due to the focus being on the possibility of using neutron-gamma variance to mean theories for both reactor and safeguards applications, we limited the present study to the general analytical expressions for Feynman-alpha formulas.

  8. MCNP capabilities at the dawn of the 21st century: Neutron-gamma applications

    SciTech Connect

    Selcow, E.C.; McKinney, G.W.

    2000-10-01

    The Los Alamos National Laboratory Monte Carlo N-Particle radiation transport code, MCNP, has become an international standard for a wide spectrum of neutron-gamma radiation transport applications. These include nuclear criticality safety, radiation shielding, nuclear safeguards, nuclear well-logging, fission and fusion reactor design, accelerator target design, detector design and analysis, health physics, medical radiation therapy and imaging, radiography, decontamination and decommissioning, and waste storage and disposal. The latest version of the code, MCNP4C, was released to the Radiation Safety Information Computational Center (RSICC) in February 2000.This paper described the new features and capabilities of the code, and discusses the specific applicability to neutron-gamma problems. We will also discuss the future directions for MCNP code development, including rewriting the code in Fortran 90.

  9. MCNP Capabilities at the Dawn of the 21st Century: Neutron-Gamma Applications

    NASA Astrophysics Data System (ADS)

    Selcow, E. C.; McKinney, G. W.; Booth, T. E.; Briesmeister, J. F.; Cox, L. J.; Forster, R. A.; Hendricks, J. S.; Mosteller, R. D.; Prael, R. E.; Sood, A.; White, S. W.

    The Los Alamos National Laboratory Monte Carlo N-Particle radiation transport code, MCNP, has become an international standard for a wide spectrum of neutron-gamma radiation transport applications. These include nuclear criticality safety, radiation shielding, nuclear safeguards, nuclear oil-well logging, fission and fusion reactor design, accelerator target design, detector design and analysis, health physics, medical radiation therapy and imaging, radiography, decontamination and decommissioning, and waste storage and disposal. The latest version of the code, MCNP4C [1], was released to the Radiation Safety Information Computational Center (RSICC) in February 2000. This paper describes the new features and capabilities of the code, and discusses the specific applicability to neutron-gamma problems. We will also discuss some of the future directions for MCNP code development.

  10. Integrated neutron/gamma-ray portal monitors for nuclear safeguards

    SciTech Connect

    Fehlau, P.E.

    1993-09-01

    Radiation monitoring is one nuclear-safeguards measure used to protect against the theft of special nuclear materials (SNM) by pedestrians departing from SNM access areas. The integrated neutron/gamma-ray portal monitor is an ideal radiation monitor for the task when the SNM is plutonium. It achieves high sensitivity for detecting both bare and shielded plutonium by combining two types of radiation detector. One type is a neutron-chamber detector, comprising a large, hollow, neutron moderator that contains a single thermal-neutron proportional counter. The entrance wall of each chamber is thin to admit slow neutrons from plutonium contained in a moderating shield, while the other walls are thick to moderate fast neutrons from bare or lead-shielded plutonium so that they can be detected. The other type of detector is a plastic scintillator that is primarily for detecting gamma rays from small amounts of unshielded plutonium. The two types of detector are easily integrated by making scintillators part of the thick back wall of each neutron chamber or by inserting them into each chamber void. We compared the influence of the two methods of integration on detecting neutrons and gamma rays, and we examined the effectiveness of other design factors and the methods for signal detection as well.

  11. Interactions between endothelial cells and T cells modulate responses to mixed neutron/gamma radiation.

    PubMed

    Cary, Lynnette H; Noutai, Daniel; Salber, Rudolph E; Williams, Margaret S; Ngudiankama, Barbara F; Whitnall, Mark H

    2014-06-01

    Detonation of an improvised nuclear device near a population center would cause significant casualties from the acute radiation syndrome (ARS) due to exposure to mixed neutron/gamma fields (MF). The pathophysiology of ARS involves inflammation, microvascular damage and alterations in immune function. Interactions between endothelial cells (EC) and hematopoietic cells are important not only for regulating immune cell traffic and function, but also for providing the microenvironment that controls survival, differentiation and migration of hematopoietic stem and progenitor cells in blood-forming tissues. Endothelial cells/leukocyte interactions also influence tumor progression and the results of anticancer therapies. In this study, we hypothesized that irradiation of endothelial cells would modulate their effects on hematopoietic cells and vice versa. Human umbilical vein endothelial cells (HUVEC) and immortalized T lymphocytes (Jurkat cells) were cultured individually and in co-culture after exposure to mixed fields. Effects of nonirradiated cells were compared to effects of irradiated cells and alterations in signaling pathways were determined. Mitogen-activated protein kinases (MAPKs) p38 and p44/42 (ERK1/2) in HUVEC exhibited higher levels of phosphorylated protein after exposure to mixed field radiation. IL-6, IL-8, G-CSF, platelet derived growth factor (PDGF) and angiopoietin 2 (ANG2) protein expression were upregulated in HUVEC by exposure to mixed field radiation. PCR arrays using HUVEC mRNA revealed alterations in gene expression after exposure to mixed fields and/or co-culture with Jurkat cells. The presence of HUVEC also influenced the function of Jurkat cells. Nonirradiated Jurkat cells showed an increase in proliferation when co-cultured with nonirradiated HUVEC, and a decrease in proliferation when co-cultured with irradiated HUVEC. Additionally, nonirradiated Jurkat cells incubated in media from irradiated HUVEC exhibited upregulation of activated

  12. ICF ignition capsule neutron, gamma ray, and high energy x-ray images

    NASA Astrophysics Data System (ADS)

    Bradley, P. A.; Wilson, D. C.; Swenson, F. J.; Morgan, G. L.

    2003-03-01

    Post-processed total neutron, RIF neutron, gamma-ray, and x-ray images from 2D LASNEX calculations of burning ignition capsules are presented. The capsules have yields ranging from tens of kilojoules (failures) to over 16 MJ (ignition), and their implosion symmetry ranges from prolate (flattest at the hohlraum equator) to oblate (flattest towards the laser entrance hole). The simulated total neutron images emphasize regions of high DT density and temperature; the reaction-in-flight neutrons emphasize regions of high DT density; the gamma rays emphasize regions of high shell density; and the high energy x rays (>10 keV) emphasize regions of high temperature.

  13. Accuracy and borehole influences in pulsed neutron gamma density logging while drilling.

    PubMed

    Yu, Huawei; Sun, Jianmeng; Wang, Jiaxin; Gardner, Robin P

    2011-09-01

    A new pulsed neutron gamma density (NGD) logging has been developed to replace radioactive chemical sources in oil logging tools. The present paper describes studies of near and far density measurement accuracy of NGD logging at two spacings and the borehole influences using Monte-Carlo simulation. The results show that the accuracy of near density is not as good as far density. It is difficult to correct this for borehole effects by using conventional methods because both near and far density measurement is significantly sensitive to standoffs and mud properties. PMID:21550259

  14. Investigation about decoupling capacitors of PMT voltage divider effects on neutron-gamma discrimination

    SciTech Connect

    Divani, Nazila Firoozabadi, Mohammad M.; Bayat, Esmail

    2014-11-24

    Scintillators are almost used in any nuclear laboratory. These detectors combine of scintillation materials, PMT and a voltage divider. Voltage dividers are different in resistive ladder design. But the effect of decoupling capacitors and damping resistors haven’t discussed yet. In this paper at first a good equilibrium circuit designed for PMT, and it was used for investigating about capacitors and resistors in much manner. Results show that decoupling capacitors have great effect on PMT output pulses. In this research, it was tried to investigate the effect of Capacitor’s value and places on PMT voltage divider in Neutron-Gamma discrimination capability. Therefore, the voltage divider circuit for R329-02 Hamamatsu PMT was made and Zero Cross method used for neutron-gamma discrimination. The neutron source was a 20Ci Am-Be. Anode and Dynode pulses and discrimination spectrum were saved. The results showed that the pulse height and discrimination quality change with the value and setting of capacitors.

  15. Development of neutron/gamma generators and a polymer semiconductor detector for homeland security applications

    NASA Astrophysics Data System (ADS)

    King, Michael Joseph

    Instrumentation development is essential to the advancement and success of homeland security systems. Active interrogation techniques that scan luggage and cargo containers for shielded special nuclear materials or explosives hold great potential in halting further terrorist attacks. The development of more economical, compact and efficient source and radiation detection devices will facilitate scanning of all containers and luggage while maintaining high-throughput and low-false alarms Innovative ion sources were developed for two novel, specialized neutron generating devices and initial generator tests were performed. In addition, a low-energy acceleration gamma generator was developed and its performance characterized. Finally, an organic semiconductor was investigated for direct fast neutron detection. A main part of the thesis work was the development of ion sources, crucial components of the neutron/gamma generator development. The use of an externally-driven radio-frequency antenna allows the ion source to generate high beam currents with high, mono-atomic species fractions while maintaining low operating pressures, advantageous parameters for neutron generators. A dual "S" shaped induction antenna was developed to satisfy the high current and large extraction area requirements of the high-intensity neutron generator. The dual antenna arrangement generated a suitable current density of 28 mA/cm2 at practical RF power levels. The stringent requirements of the Pulsed Fast Neutron Transmission Spectroscopy neutron generator necessitated the development of a specialized ten window ion source of toroidal shape with a narrow neutron production target at its center. An innovative ten antenna arrangement with parallel capacitors was developed for driving the multi-antenna arrangement and uniform coupling of RF power to all ten antennas was achieved. To address the desire for low-impact, low-radiation dose active interrogation systems, research was performed on mono

  16. The field theory of specific heat

    NASA Astrophysics Data System (ADS)

    Gusev, Yu. V.

    2016-01-01

    Finite temperature quantum field theory in the heat kernel method is used to study the heat capacity of condensed matter. The lattice heat is treated à la P. Debye as energy of the elastic (sound) waves. The dimensionless functional of free energy is re-derived with a cut-off parameter and used to obtain the specific heat of crystal lattices. The new dimensionless thermodynamical variable is formed as Planck's inverse temperature divided by the lattice constant. The dimensionless constant, universal for the class of crystal lattices, which determines the low temperature region of molar specific heat, is introduced and tested with the data for diamond lattice crystals. The low temperature asymptotics of specific heat is found to be the fourth power in temperature instead of the cubic power law of the Debye theory. Experimental data for the carbon group elements (silicon, germanium) and other materials decisively confirm the quartic law. The true low temperature regime of specific heat is defined by the surface heat, therefore, it depends on the geometrical characteristics of the body, while the absolute zero temperature limit is geometrically forbidden. The limit on the growth of specific heat at temperatures close to critical points, known as the Dulong-Petit law, appears from the lattice constant cut-off. Its value depends on the lattice type and it is the same for materials with the same crystal lattice. The Dulong-Petit values of compounds are equal to those of elements with the same crystal lattice type, if one mole of solid state matter were taken as the Avogadro number of the composing atoms. Thus, the Neumann-Kopp law is valid only in some special cases.

  17. Fast-neutron/gamma-ray radiography scanner for the detection of contraband in air cargo containers

    NASA Astrophysics Data System (ADS)

    Eberhardt, J.; Liu, Y.; Rainey, S.; Roach, G.; Sowerby, B.; Stevens, R.; Tickner, J.

    2006-05-01

    There is a worldwide need for efficient inspection of cargo containers at airports, seaports and road border crossings. The main objectives are the detection of contraband such as illicit drugs, explosives and weapons. Due to the large volume of cargo passing through Australia's airports every day, it is critical that any scanning system should be capable of working on unpacked or consolidated cargo, taking at most 1-2 minutes per container. CSIRO has developed a fast-neutron/gamma-ray radiography (FNGR) method for the rapid screening of air freight. By combining radiographs obtained using 14 MeV neutrons and 60Co gamma-rays, high resolution images showing both density and material composition are obtained. A near full-scale prototype scanner has been successfully tested in the laboratory. With the support of the Australian Customs Service, a full-scale scanner has recently been installed and commissioned at Brisbane International Airport.

  18. Neutron-gamma discrimination based on the support vector machine method

    NASA Astrophysics Data System (ADS)

    Yu, Xunzhen; Zhu, Jingjun; Lin, ShinTed; Wang, Li; Xing, Haoyang; Zhang, Caixun; Xia, Yuxi; Liu, Shukui; Yue, Qian; Wei, Weiwei; Du, Qiang; Tang, Changjian

    2015-03-01

    In this study, the combination of the support vector machine (SVM) method with the moment analysis method (MAM) is proposed and utilized to perform neutron/gamma (n/γ) discrimination of the pulses from an organic liquid scintillator (OLS). Neutron and gamma events, which can be firmly separated on the scatter plot drawn by the charge comparison method (CCM), are detected to form the training data set and the test data set for the SVM, and the MAM is used to create the feature vectors for individual events in the data sets. Compared to the traditional methods, such as CCM, the proposed method can not only discriminate the neutron and gamma signals, even at lower energy levels, but also provide the corresponding classification accuracy for each event, which is useful in validating the discrimination. Meanwhile, the proposed method can also offer a predication of the classification for the under-energy-limit events.

  19. Fast neutron-gamma discrimination on neutron emission profile measurement on JT-60U

    SciTech Connect

    Ishii, K.; Okamoto, A.; Kitajima, S.; Sasao, M.; Shinohara, K.; Ishikawa, M.; Baba, M.; Isobe, M.

    2010-10-15

    A digital signal processing (DSP) system is applied to stilbene scintillation detectors of the multichannel neutron emission profile monitor in JT-60U. Automatic analysis of the neutron-{gamma} pulse shape discrimination is a key issue to diminish the processing time in the DSP system, and it has been applied using the two-dimensional (2D) map. Linear discriminant function is used to determine the dividing line between neutron events and {gamma}-ray events on a 2D map. In order to verify the validity of the dividing line determination, the pulse shape discrimination quality is evaluated. As a result, the {gamma}-ray contamination in most of the beam heating phase was negligible compared with the statistical error with 10 ms time resolution.

  20. Neutron, gamma ray, and temperature effects on the electrical characteristics of thyristors

    NASA Technical Reports Server (NTRS)

    Frasca, A. J.; Schwarze, G. E.

    1992-01-01

    Experimental data showing the effects of neutrons, gamma rays, and temperature on the electrical and switching characteristics of phase-control and inverter-type SCR's are presented. The special test fixture built for mounting, heating, and instrumenting the test devices is described. Four SCR's were neutron irradiated at 300 K and four at 365 K for fluences up to 3.2 x 10 exp 13 pn/sq. cm, and eight were gamma irradiated at 300 K only for gamma doses up to 5.1 Mrads. The electrical measurements were made during irradiation and the switching measurements were made only before and after irradiation. Radiation induced crystal defects, resulting primarily from fast neutrons, caused the reduction of minority carrier lifetime through the generation of R-G centers. The reduction in lifetime caused increases in the on-state voltage drop and in the reverse and forward leakage currents, and decreases in the turn-off time.

  1. Neutron, gamma ray, and temperature effects on the electrical characteristics of thyristors

    NASA Technical Reports Server (NTRS)

    Frasca, A. J.; Schwarze, G. E.

    1992-01-01

    Experimental data showing the effects of neutrons, gamma rays, and temperature on the electrical and switching characteristics of phase-control and inverter-type SCR's are presented. The special test fixture built for mounting, heating, and instrumenting the test devices is described. Four SCR's were neutron irradiated at 300 K and four at 365 K for fluences up to 3.2 x 10 exp 13 n/sq. cm, and eight were gamma irradiated at 300 K only for gamma doses up to 5.1 Mrads. The electrical measurements were made during irradiation and the switching measurements were made only before and after irradiation. Radiation induced crystal defects, resulting primarily from fast neutrons, caused the reduction of minority carrier lifetime through the generation of R-G centers. The reduction in lifetime caused increases in the on-state voltage drop and in the reverse and forward leakage currents, and decreases in the turn-off time.

  2. Global and site specific multimedia (field) studies

    SciTech Connect

    Cutshall, N.H.; Guerin, M.R.

    1987-01-01

    Experience with radioactive fallout, with organic contaminants and with heavy metals has amply demonstrated that cross-media transfers are common and that understanding the transport, cycling, and fate of these contaminants requires a multimedia approach. Nonetheless, pollutants with similar physical and chemical attributes may follow markedly different pathways. The frequency of exceptions to predictions based on simplistic models is also sufficient to show that direct investigation of environmental contamination is essential to confirm validity of models used for conceptualizing a problem or for control. Modeling based on multimedia premises and regulatory controls that encompass multimedia considerations are challenged by a dilemma, however. First, the development of multimedia models or regulatory frameworks represents simplification and generalization. This is true for several reasons: (1) inadequate understanding of physical and environmental factors which control specific cross-media transfer; (2) the absence of specific data on certain multimedia pollutant concentrations; (3) even the most powerful computers do not have sufficient speed and capacity to deal with the known complexities of natural systems. On the other hand, for contaminants such as mercury, it may be necessary to include great detail; the overall distribution in the environment may be less important than the rate of some minor process. With sufficient experience and good judgment of what can be ignored, the simplifications and generalizations can be made. For the present, and for the foreseeable future, however, they absolutely must be accompanied by thorough field validation and monitoring.

  3. Monitoring Neutron Generator Output in a Mixed Neutron-Gamma Field Using a Plastic Scintillator.

    SciTech Connect

    Mitra,S.; Wielopolski, L.

    2007-10-28

    Quantitative neutron-induced gamma-ray spectroscopy employing neutron generators (NGs) entails monitoring them for possible fluctuations in their neutron output. We accomplished this using a plastic scintillator and recording a spectrum from which we selected a neutron region-of-interest (nROI) to discriminate between neutrons and the accompanying high-energy gamma-rays. We show that the selected nROI is insensitive to changes in the gamma-ray background, thus allowing satisfactory normalization of the gamma-ray spectra of an in-situ system for analyzing soil carbon.

  4. Novel deployment of elpasolites as a dual neutron / gamma- ray directional detector

    NASA Astrophysics Data System (ADS)

    Guckes, Amber

    (FOM) of 2.3. An array of three CLYC detectors was assembled for the purpose of directional neutron / gamma-ray detection. The intrinsic peak efficiency of CLYC detectors was evaluated. The three-CLYC detector array was deployed for directional measurements with a single gamma-ray 137Cs source, two gamma-ray sources of 137Cs and 60Co isotopes and a thermal neutron source designed using a 239PuBe neutron source supplied with a polyethylene moderator. Measurements were carried out using sources located in the longitude and latitude planes over the angles from 0° to 360°. The measured data were processed through a maximum likelihood estimation algorithm providing a possible direction for which the radioactive source in each case was positioned. The estimated directions were close if not exact matches for the actual directions to the radioactive source. The largest discrepancy in direction produced by the algorithm was approximately 11%. However, it was hypothesized that this percent error can be decreased by homogenizing the directional detection system to consist of scintillators of the same size and quality, identical photomultiplier tubes and identical aluminum housings. The feasibility of this hypothesis to decrease the percent error was confirmed by the zero percent error achieved in the directional measurements produced in the computational study utilizing a homogenous directional detection system. The results of computational and experimental studies completed within this research project provide means to propose the array of three CLYC scintillators as an efficient dual neutron / gamma-ray directional detector.

  5. Improved neutron-gamma discrimination for a 6Li-glass neutron detector using digital signal analysis methods

    DOE PAGESBeta

    Wang, Cai -Lin; Riedel, Richard A.

    2016-01-14

    A 6Li-glass scintillator (GS20) based neutron Anger camera was developed for time-of-flight single-crystal diffraction instruments at SNS. Traditional pulse-height analysis (PHA) for neutron-gamma discrimination (NGD) resulted in the neutron-gamma efficiency ratio (defined as NGD ratio) on the order of 104. The NGD ratios of Anger cameras need to be improved for broader applications including neutron reflectometers. For this purpose, five digital signal analysis methods of individual waveforms from PMTs were proposed using: i). pulse-amplitude histogram; ii). power spectrum analysis combined with the maximum pulse amplitude; iii). two event parameters (a1, b0) obtained from Wiener filter; iv). an effective amplitude (m)more » obtained from an adaptive least-mean-square (LMS) filter; and v). a cross-correlation (CC) coefficient between an individual waveform and a reference. The NGD ratios can be 1-102 times those from traditional PHA method. A brighter scintillator GS2 has better NGD ratio than GS20, but lower neutron detection efficiency. The ultimate NGD ratio is related to the ambient, high-energy background events. Moreover, our results indicate the NGD capability of neutron Anger cameras can be improved using digital signal analysis methods and brighter neutron scintillators.« less

  6. Improved neutron-gamma discrimination for a 6Li-glass neutron detector using digital signal analysis methods

    NASA Astrophysics Data System (ADS)

    Wang, C. L.; Riedel, R. A.

    2016-01-01

    A 6Li-glass scintillator (GS20) based neutron Anger camera was developed for time-of-flight single-crystal diffraction instruments at Spallation Neutron Source. Traditional Pulse-Height Analysis (PHA) for Neutron-Gamma Discrimination (NGD) resulted in the neutron-gamma efficiency ratio (defined as NGD ratio) on the order of 104. The NGD ratios of Anger cameras need to be improved for broader applications including neutron reflectometers. For this purpose, six digital signal analysis methods of individual waveforms acquired from photomultiplier tubes were proposed using (i) charge integration, (ii) pulse-amplitude histograms, (iii) power spectrum analysis combined with the maximum pulse-amplitude, (iv) two event parameters (a1, b0) obtained from a Wiener filter, (v) an effective amplitude (m) obtained from an adaptive least-mean-square filter, and (vi) a cross-correlation coefficient between individual and reference waveforms. The NGD ratios are about 70 times those from the traditional PHA method. Our results indicate the NGD capabilities of neutron Anger cameras based on GS20 scintillators can be significantly improved with digital signal analysis methods.

  7. Improved neutron-gamma discrimination for a (6)Li-glass neutron detector using digital signal analysis methods.

    PubMed

    Wang, C L; Riedel, R A

    2016-01-01

    A (6)Li-glass scintillator (GS20) based neutron Anger camera was developed for time-of-flight single-crystal diffraction instruments at Spallation Neutron Source. Traditional Pulse-Height Analysis (PHA) for Neutron-Gamma Discrimination (NGD) resulted in the neutron-gamma efficiency ratio (defined as NGD ratio) on the order of 10(4). The NGD ratios of Anger cameras need to be improved for broader applications including neutron reflectometers. For this purpose, six digital signal analysis methods of individual waveforms acquired from photomultiplier tubes were proposed using (i) charge integration, (ii) pulse-amplitude histograms, (iii) power spectrum analysis combined with the maximum pulse-amplitude, (iv) two event parameters (a1, b0) obtained from a Wiener filter, (v) an effective amplitude (m) obtained from an adaptive least-mean-square filter, and (vi) a cross-correlation coefficient between individual and reference waveforms. The NGD ratios are about 70 times those from the traditional PHA method. Our results indicate the NGD capabilities of neutron Anger cameras based on GS20 scintillators can be significantly improved with digital signal analysis methods. PMID:26827314

  8. An overview of field-specific designs of microbial EOR

    SciTech Connect

    Robertson, E.P.; Bala, G.A.; Fox, S.L.; Jackson, J.D.; Thomas, C.P.

    1995-12-31

    The selection and design of an MEOR process for application in a specific field involves geological, reservoir, and biological characterization. Microbially mediated oil recovery mechanisms (bigenic gas, biopolymers, and biosurfactants) are defined by the types of microorganisms used. The engineering and biological character of a given reservoir must be understood to correctly select a microbial system to enhance oil recovery. This paper discusses the methods used to evaluate three fields with distinct characteristics and production problems for the applicability of MEOR would not be applicable in two of the three fields considered. The development of a microbial oil recovery process for the third field appeared promising. Development of a bacterial consortium capable of producing the desired metabolites was initiated, and field isolates were characterized.

  9. An overview of field specific designs of microbial EOR

    SciTech Connect

    Robertson, E.P.; Bala, G.A.; Fox, S.L.; Jackson, J.D.; Thomas, C.P.

    1995-12-01

    The selection and design of a microbial enhanced oil recovery (MEOR) process for application in a specific field involves geological, reservoir, and biological characterization. Microbially mediated oil recovery mechanisms (biogenic gas, biopolymers, and biosurfactants) are defined by the types of microorganisms used. The engineering and biological character of a given reservoir must be understood to correctly select a microbial system to enhance oil recovery. The objective of this paper is to discuss the methods used to evaluate three fields with distinct characteristics and production problems for the applicability of MEOR technology. Reservoir characteristics and laboratory results indicated that MEOR would not be applicable in two of the three fields considered. The development of a microbial oil recovery process for the third field appeared promising. Development of a bacterial consortium capable of producing the desired metabolites was initiated and field isolates were characterized.

  10. Dose homogeneity specification for reference dosimetry of nonstandard fields

    SciTech Connect

    Chung, Eunah; Soisson, Emilie; Seuntjens, Jan

    2012-01-15

    Purpose: To investigate the sensitivity of the plan-class specific correction factor to dose distributions in composite nonstandard field dosimetry. Methods: A cylindrical water-filled PMMA phantom was constructed at the center of which reference absorbed dose could be measured. Ten different TomoTherapy-based IMRT fields were created on the CT images of the phantom. The dose distribution for each IMRT field was estimated at the position of a radiation detector or ionization chamber. The dose in each IMRT field normalized to that in a reference 10 x 10 cm{sup 2} field was measured using a PTW micro liquid ion chamber. Based on the new dosimetry formalism, a plan-class specific correction factor k{sub Q{sub p{sub c{sub s{sub r,Q}{sup f{sub p}{sub c}{sub s}{sub r},f{sub r}{sub e}{sub f}}}}}} for each field was measured for two Farmer-type chambers, Exradin A12 and NE2571, as well as for a smaller Exradin A1SL chamber. The dependence of the measured correction factor on parameters characterizing dose distribution was analyzed. Results: Uncertainty on the plan-class specific correction factor measurement was in the range of 0.3%-0.5% and 0.3%-0.8% for the Farmer-type chambers and the Exradin A1SL, respectively. When the heterogeneity of the central region of the target volume was less than 5%, the correction factor did not differ from unity by more than 0.7% for the three air-filled ionization chambers. For more heterogeneous dose deliveries, the correction factor differed from unity by up to 2.4% for the Farmer-type chambers. For the Exradin A1SL, the correction factor was closer to unity due to the reduced effect of dose gradients, while it was highly variable in different IMRT fields because of a more significant impact of positioning uncertainties on the response of this chamber. Conclusions: The authors have shown that a plan-class specific correction factor can be specified as a function of plan evaluation parameters especially for Farmer-type chambers. This work

  11. Magnetic Field Satellite (Magsat) data processing system specifications

    NASA Technical Reports Server (NTRS)

    Berman, D.; Gomez, R.; Miller, A.

    1980-01-01

    The software specifications for the MAGSAT data processing system (MDPS) are presented. The MDPS is divided functionally into preprocessing of primary input data, data management, chronicle processing, and postprocessing. Data organization and validity, and checks of spacecraft and instrumentation are dicussed. Output products of the MDPS, including various plots and data tapes, are described. Formats for important tapes are presented. Dicussions and mathematical formulations for coordinate transformations and field model coefficients are included.

  12. Development of a specific anaerobic field test for aerobic gymnastics.

    PubMed

    Alves, Christiano Robles Rodrigues; Borelli, Marcello Tadeu Caetano; Paineli, Vitor de Salles; Azevedo, Rafael de Almeida; Borelli, Claudia Cristine Gomes; Lancha Junior, Antônio Herbert; Gualano, Bruno; Artioli, Guilherme Giannini

    2015-01-01

    The current investigation aimed to develop a valid specific field test to evaluate anaerobic physical performance in Aerobic Gymnastics athletes. We first designed the Specific Aerobic Gymnast Anaerobic Test (SAGAT), which included gymnastics-specific elements performed in maximal repeated sprint fashion, with a total duration of 80-90 s. In order to validate the SAGAT, three independent sub-studies were performed to evaluate the concurrent validity (Study I, n=8), the reliability (Study II, n=10) and the sensitivity (Study III, n=30) of the test in elite female athletes. In Study I, a positive correlation was shown between lower-body Wingate test and SAGAT performance (Mean power: p = 0.03, r = -0.69, CI: -0.94 to 0.03 and Peak power: p = 0.02, r = -0.72, CI: -0.95 to -0.04) and between upper-body Wingate test and SAGAT performance (Mean power: p = 0.03, r = -0.67, CI: -0.94 to 0.02 and Peak power: p = 0.03, r = -0.69, CI: -0.94 to 0.03). Additionally, plasma lactate was similarly increased in response to SAGAT (p = 0.002), lower-body Wingate Test (p = 0.021) and a simulated competition (p = 0.007). In Study II, no differences were found between the time to complete the SAGAT in repeated trials (p = 0.84; Cohen's d effect size = 0.09; ICC = 0.97, CI: 0.89 to 0.99; MDC95 = 0.12 s). Finally, in Study III the time to complete the SAGAT was significantly lower during the competition cycle when compared to the period before the preparatory cycle (p < 0.001), showing an improvement in SAGAT performance after a specific Aerobic Gymnastics training period. Taken together, these data have demonstrated that SAGAT is a specific, reliable and sensitive measurement of specific anaerobic performance in elite female Aerobic Gymnastics, presenting great potential to be largely applied in training settings. PMID:25876039

  13. Development of a Specific Anaerobic Field Test for Aerobic Gymnastics

    PubMed Central

    Paineli, Vitor de Salles; Azevedo, Rafael de Almeida; Borelli, Claudia Cristine Gomes; Lancha Junior, Antônio Herbert; Gualano, Bruno; Artioli, Guilherme Giannini

    2015-01-01

    The current investigation aimed to develop a valid specific field test to evaluate anaerobic physical performance in Aerobic Gymnastics athletes. We first designed the Specific Aerobic Gymnast Anaerobic Test (SAGAT), which included gymnastics-specific elements performed in maximal repeated sprint fashion, with a total duration of 80-90 s. In order to validate the SAGAT, three independent sub-studies were performed to evaluate the concurrent validity (Study I, n=8), the reliability (Study II, n=10) and the sensitivity (Study III, n=30) of the test in elite female athletes. In Study I, a positive correlation was shown between lower-body Wingate test and SAGAT performance (Mean power: p = 0.03, r = -0.69, CI: -0.94 to 0.03 and Peak power: p = 0.02, r = -0.72, CI: -0.95 to -0.04) and between upper-body Wingate test and SAGAT performance (Mean power: p = 0.03, r = -0.67, CI: -0.94 to 0.02 and Peak power: p = 0.03, r = -0.69, CI: -0.94 to 0.03). Additionally, plasma lactate was similarly increased in response to SAGAT (p = 0.002), lower-body Wingate Test (p = 0.021) and a simulated competition (p = 0.007). In Study II, no differences were found between the time to complete the SAGAT in repeated trials (p = 0.84; Cohen’s d effect size = 0.09; ICC = 0.97, CI: 0.89 to 0.99; MDC95 = 0.12 s). Finally, in Study III the time to complete the SAGAT was significantly lower during the competition cycle when compared to the period before the preparatory cycle (p < 0.001), showing an improvement in SAGAT performance after a specific Aerobic Gymnastics training period. Taken together, these data have demonstrated that SAGAT is a specific, reliable and sensitive measurement of specific anaerobic performance in elite female Aerobic Gymnastics, presenting great potential to be largely applied in training settings. PMID:25876039

  14. Mobile neutron/gamma waste assay system for characterization of waste containing transuranics, uranium, and fission/activation products

    SciTech Connect

    Davidson, D.R.; Haggard, D.; Lemons, C.

    1994-12-31

    A new integrated neutron/gamma assay system has been built for measuring 55-gallon drums at Pacific Northwest Laboratory. The system is unique because it allows simultaneous measurement of neutrons and gamma-rays. This technique also allows measurement of transuranics (TRU), uranium, and fission/activation products, screening for shielded Special Nuclear Material prior to disposal, and critically determinations prior to transportation. The new system is positioned on a platform with rollers and installed inside a trailer or large van to allow transportation of the system to the waste site instead of movement of the drums to the scanner. The ability to move the system to the waste drums is particularly useful for drum retrieval programs common to all DOE sites and minimizes transportation problems on the site. For longer campaigns, the system can be moved into a facility. The mobile system consists of two separate subsystems: a passive Segmented Gamma Scanner (SGS) and a {open_quotes}clam-shell{close_quotes} passive neutron counter. The SGS with high purity germanium detector and {sup 75}Se transmission source simultaneously scan the height of the drum allowing identification of unshieled {open_quotes}hot spots{close_quotes} in the drum or segments where the matrix is too dense for the transmission source to penetrate. Dense segments can flag shielding material that could be used to hide plutonium or uranium during the gamma analysis. The passive nuetron counter with JSR-12N Neutron Coincidence Analyzer measures the coincident neutrons from the spontaneous fission of even isotopes of plutonium. Because high-density shielding produces minimal absorption of neutrons, compared to gamma rays, the passive neutron portion of the system can detect shielded SNM. Measurements to evaluate the performance of the system are still underway at Pacific Northwest Laboratory.

  15. Radiation effect on silicon transistors in mixed neutrons-gamma environment

    NASA Astrophysics Data System (ADS)

    Assaf, J.; Shweikani, R.; Ghazi, N.

    2014-10-01

    The effects of gamma and neutron irradiations on two different types of transistors, Junction Field Effect Transistor (JFET) and Bipolar Junction Transistor (BJT), were investigated. Irradiation was performed using a Syrian research reactor (RR) (Miniature Neutron Source Reactor (MNSR)) and a gamma source (Co-60 cell). For RR irradiation, MCNP code was used to calculate the absorbed dose received by the transistors. The experimental results showed an overall decrease in the gain factors of the transistors after irradiation, and the JFETs were more resistant to the effects of radiation than BJTs. The effect of RR irradiation was also greater than that of gamma source for the same dose, which could be because neutrons could cause more damage than gamma irradiation.

  16. Neutron, gamma ray and post-irradiation thermal annealing effects on power semiconductor switches

    NASA Technical Reports Server (NTRS)

    Schwarze, G. E.; Frasca, A. J.

    1991-01-01

    Experimental data showing the effects of neutrons and gamma rays on the performance characteristics of power-type NPN bipolar junction transistors (BJTs), metal-oxide-semiconductor field effect transistors (MOSFETs), and static induction transistors (SITs) are given. These three types of devices were tested at radiation levels which met or exceeded the SP-100 requirements. For the SP-100 radiation requirements, the BJTs were found to be most sensitive to neutrons, the MOSFETs were most sensitive to gamma rays, and the SITs were only slightly sensitive to neutrons. Postirradiation thermal anneals at 300 K and up to 425 K were done on these devices and the effectiveness of these anneals are also discussed.

  17. Neutron/gamma dose separation by the multiple-ion-chamber technique

    SciTech Connect

    Goetsch, S.J.

    1983-01-01

    Many mixed n/..gamma.. dosimetry systems rely on two dosimeters, one composed of a tissue-equivalent material and the other made from a non-hydrogenous material. The paired chamber technique works well in fields of neutron radiation nearly identical in spectral composition to that in which the dosimeters were calibrated. However, this technique is drastically compromised in phantom due to the degradation of the neutron spectrum. The three-dosimeter technique allows for the fall-off in neutron sensitivity of the two non-hydrogenous dosimeters. Precise and physically meaningful results were obtained with this technique with a D-T source in air and in phantom and with simultaneous D-T neutron and /sup 60/Co gamma ray irradiation in air. The MORSE-CG coupled n/..gamma.. three-dimensional Monte Carlo code was employed to calculate neutron and gamma doses in a water phantom. Gamma doses calculated in phantom with this code were generally lower than corresponding ion chamber measurements. This can be explained by the departure of irradiation conditions from ideal narrow-beam geometry. 97 references.

  18. Neutron, gamma ray and post-irradiation thermal annealing effects on power semiconductor switches

    NASA Technical Reports Server (NTRS)

    Schwarze, G. E.; Frasca, A. J.

    1991-01-01

    The effects of neutron and gamma rays on the electrical and switching characteristics of power semiconductor switches must be known and understood by the designer of the power conditioning, control, and transmission subsystem of space nuclear power systems. The SP-100 radiation requirements at 25 m from the nuclear source are a neutron fluence of 10(exp 13) n/sq cm and a gamma dose of 0.5 Mrads. Experimental data showing the effects of neutrons and gamma rays on the performance characteristics of power-type NPN Bipolar Junction Transistors (BJTs), Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs), and Static Induction Transistors (SITs) are presented. These three types of devices were tested at radiation levels which met or exceeded the SP-100 requirements. For the SP-100 radiation requirements, the BJTs were found to be most sensitive to neutrons, the MOSFETs were most sensitive to gamma rays, and the SITs were only slightly sensitive to neutrons. Post-irradiation thermal anneals at 300 K and up to 425 K were done on these devices and the effectiveness of these anneals are also discussed.

  19. MA-NRBC: First successful attempt for neutron gamma discrimination in plastic scintillators

    SciTech Connect

    Normand, S.; Kondrasovs, V.; Corre, G.; Bourbotte, J. M.; Ferragut, A.

    2011-07-01

    In this paper, a new electronic hardware and algorithms enabling discrimination between neutron and gamma in plastic scintillators together with the first associated experimental results, are presented. This electronic platform is mainly based onto a quad 200 MHz ADCs. Using phase rotating, it is possible to sample the signal up to 800 MHz equivalent, with 8 bits precision. This sampling frequency allows a real time signal processing. Despite all previous work, we have shown during this study that it is possible to discriminate neutron from gamma in plastic scintillators even for low energy neutrons (less than 10 MeV). Two patents have been accepted and registered; the first deals with the intrinsic signal processing and the second with thermal stabilization methods of photomultiplier tubes. The system could be used up to 100 000 events per second (both gamma and neutron). This system is currently dedicated to homeland security devices; this is due to its response time (in the order of 1 up to 3 seconds). The next step is to implement the thermal stabilization algorithm in the FPGA and micro-controller to obtain a global system free from any trouble caused by the environment thermal variations. This aspect of the research is crucial for measurements in the field. The time response should also be improved to make it a reliable alternative to Helium-3 shortage for neutron detection at borders checkpoint. (authors)

  20. Neutron, gamma ray and post-irradiation thermal annealing effects on power semiconductor switches

    SciTech Connect

    Schwarze, G.E.; Frasca, A.J.

    1994-09-01

    The effects of neutrons and gamma rays on the electrical and switching characteristics of power semiconductor switches must be known and understood by the designer of the power conditioning, control, and transmission subsystem of space nuclear power systems. The SP-100 radiation requirements at 25 m from the nuclear source are a neutron fluence of 10{sup 13} n/cm {sup 2} and a gamma dose of 0.5 Mrads. Experimental data showing the effects of neutrons and gamma rays on the performance characteristics of power-type NPN Bipolar Junction Transistors (BJTs), Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs), and Static Induction Transistors (SITs) are given in this paper. These three types of devices were tested at radiation levels which met or exceeded the SP-100 requirements. For the SP-100 radiation requirements, the BJTs were found to be most sensitive to neutrons, the MOSFETs were most sensitive to gamma rays, and the SITs were only slightly sensitive to neutrons. Post-irradiation thermal anneals at 300 K and up to 425 K were done on these devices and the effectiveness of these anneals are also discussed.

  1. Pulsed-Neutron-Gamma (PNG) saturation monitoring at the Ketzin pilot site considering displacement and evaporation/precipitation processes

    NASA Astrophysics Data System (ADS)

    Baumann, Gunther; Henninges, Jan

    2013-04-01

    The storage of carbon dioxide (CO2) in saline aquifers is a promising option to reduce emissions of greenhouse gases to the atmosphere and to mitigate global climate change. During the proposed CO2 injection process, application of suitable techniques for monitoring of the induced changes in the subsurface is required. Existing models for the spreading of the CO2, as well as mixing of the different fluids associated with saturation changes or resulting issues from mutual solubility between brine and CO2, need to be checked. For well logging in cased boreholes, which would be the standard situation encountered under the given conditions, only a limited number of techniques like pulsed neutron-gamma (PNG) logging are applicable. The PNG technique uses controlled neutron bursts, which interact with the nuclei of the surrounding borehole and formation. Due to the collision with these neutrons, atoms from the surrounding environment emit gamma rays. The main PNG derived parameter is the capture cross section (Σ) which is derived from the decline of gamma rays with time from neutron capture processes. The high Σ contrast between brine and CO2 results in a high sensitivity to evaluate saturation changes. This makes PNG monitoring favourable for saturation profiling especially in time-lapse mode. Previously, the conventional PNG saturation model based on a displacement process has been used for PNG interpretation in different CO2 storage projects in saline aquifers. But in addition to the displacement process, the mutual solubility between brine and CO2 adds further complex processes like evaporation and salt precipitation, which are not considered in PNG saturation models. These evaporation and precipitation processes are relevant in the vicinity of an injection well, where dry CO2 enters the reservoir. The Σ brine value depends strongly on the brine salinity e.g. its chlorine content which makes PNG measurements suitable for evaporation and salt precipitation

  2. [Psychotherapy in the somatic field--what specificities?].

    PubMed

    Verdu, B; Krenz, S; Ludwig, G; Stagno, D

    2010-09-22

    This article illustrates some of the specific aspects of the psychotherapeutic approach with medically ill patients. Our considerations are based on our daily work in CL Psychiatry and refer to the psychodynamic model, rooted in Freudian's thought. Characteristics are the setting, as well as the relationship with the patient and the interactions with the physicians as the "emergence" of the suffering body within the therapy. We therefore adopt specific approaches such as the work with the Auxiliary Ego and the narrative reconstruction. This paper illustrates our experiences applying the mentioned tools with patients suffering from chronic pain and cancer. PMID:20963960

  3. 40 CFR 86.1375-2007 - Equipment specifications for field testing.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-Exceed test procedures, use the test procedures and equipment specified in 40 CFR part 1065, subpart J. ... 40 Protection of Environment 20 2013-07-01 2013-07-01 false Equipment specifications for field... Exhaust Test Procedures § 86.1375-2007 Equipment specifications for field testing. For testing...

  4. 40 CFR 86.1375-2007 - Equipment specifications for field testing.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-Exceed test procedures, use the test procedures and equipment specified in 40 CFR part 1065, subpart J. ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Equipment specifications for field... Exhaust Test Procedures § 86.1375-2007 Equipment specifications for field testing. For testing...

  5. 40 CFR 86.1375-2007 - Equipment specifications for field testing.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-Exceed test procedures, use the test procedures and equipment specified in 40 CFR part 1065, subpart J. ... 40 Protection of Environment 19 2011-07-01 2011-07-01 false Equipment specifications for field... Exhaust Test Procedures § 86.1375-2007 Equipment specifications for field testing. For testing...

  6. Neutron Reference Benchmark Field Specification: ACRR Free-Field Environment (ACRR-FF-CC-32-CL).

    SciTech Connect

    Vega, Richard Manuel; Parma, Edward J.; Griffin, Patrick J.; Vehar, David W.

    2015-07-01

    This report was put together to support the International Atomic Energy Agency (IAEA) REAL- 2016 activity to validate the dosimetry community’s ability to use a consistent set of activation data and to derive consistent spectral characterizations. The report captures details of integral measurements taken in the Annular Core Research Reactor (ACRR) central cavity free-field reference neutron benchmark field. The field is described and an “a priori” calculated neutron spectrum is reported, based on MCNP6 calculations, and a subject matter expert (SME) based covariance matrix is given for this “a priori” spectrum. The results of 31 integral dosimetry measurements in the neutron field are reported.

  7. Subject-Specific Models of Susceptibility-Induced B0 Field Variations in Breast MRI

    PubMed Central

    Jordan, Caroline D.; Daniel, Bruce L.; Koch, Kevin M.; Yu, Huanzhou; Conolly, Steve; Hargreaves, Brian A.

    2012-01-01

    PURPOSE To rapidly calculate and validate subject-specific field maps based on the 3D shape of the bilateral breast volume. MATERIALS AND METHODS Ten healthy female volunteers were scanned at 3T using a multi-echo sequence that provides water, fat, in-phase, out-of-phase and field map images. A shape-specific binary mask was automatically generated to calculate a computed field map using a dipole field model. The measured and computed field maps were compared by visualizing the spatial distribution of the difference field map, the mean absolute error, and the 80% distribution widths of frequency histograms. RESULTS The ten computed field maps had a mean absolute error of 38 Hz (0.29 ppm) compared to the measured field maps. The average 80% distribution widths for the histograms of all of the computed, measured and difference field maps are 205 Hz, 233 Hz, and 120 Hz, respectively. CONCLUSION The computed field maps had substantial overall agreement with the measured field maps, indicating that breast MRI field maps can be computed based on the air-tissue interfaces. These estimates may provide a predictive model for field variations and thus have the potential to improve applications in breast MRI. PMID:22865658

  8. Field estimation of specific yield in a Central Iowa crop field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The specific yield (Sy) is the gain or loss of water associated with water table rise or fall. Rain is partially intercepted by the canopy, refills the soil pore system, or may be taken up by plant roots growing in the soil pores before reaching the water table. Water lost from the root zone may be ...

  9. Delayed magnetic mismatch negativity field, but not auditory M100 response, in Specific Language Impairment

    PubMed Central

    Roberts, T.P.L.; Heiken, K.; Kahn, S.Y.; Qasmieh, S.; Blaskey, L.; Solot, C.; Parker, W.A.; Verma, R; Edgar, J.C.

    2012-01-01

    Recent studies show that electrophysiological markers of auditory processing such as the cortical 100ms response (M100) and the mismatch field (MMF), derived from magnetoencephalography (MEG), might be used to identify children with autism spectrum disorders - M100 peak latency - and to stratify children with autism according to the degree of language impairment – mismatch field peak latency. The present study examined the latencies of right superior temporal gyrus M100 and mismatch field in a cohort of children and young adolescents with specific language impairment (n=17), in comparison to age and non-verbal IQ matched typically developing controls (n=21). Neither group showed symptoms associated with autism. Whereas M100 latency (reflecting early auditory processing) did not distinguish controls from children with specific language impairment, the later “change detection” mismatch field response was significantly delayed (by >50ms) in the specific language impairment group. Linear discriminant analysis confirmed the role of mismatch field latency (92%) but not M100 latency (8%) in distinguishing groups. Present results add support to the claim that a delayed M100 is specific to autism spectrum disorders (with relative independence of degree of language impairment) and that a delayed mismatch field reflects an abnormality more generally associated with language impairment, suggesting that mismatch field delay in the present specific language impairment group and previously reported in autistic children with language impairment may be indicative of a common neural system dysfunction. PMID:22551948

  10. Assessing Field-Specific Risk of Soybean Sudden Death Syndrome Using Satellite Imagery in Iowa.

    PubMed

    Yang, S; Li, X; Chen, C; Kyveryga, P; Yang, X B

    2016-08-01

    Moderate resolution imaging spectroradiometer (MODIS) satellite imagery from 2004 to 2013 were used to assess the field-specific risks of soybean sudden death syndrome (SDS) caused by Fusarium virguliforme in Iowa. Fields with a high frequency of significant decrease (>10%) of the normalized difference vegetation index (NDVI) observed in late July to middle August on historical imagery were hypothetically considered as high SDS risk. These high-risk fields had higher slopes and shorter distances to flowlines, e.g., creeks and drainages, particularly in the Des Moines lobe. Field data in 2014 showed a significantly higher SDS level in the high-risk fields than fields selected without considering NDVI information. On average, low-risk fields had 10 times lower F. virguliforme soil density, determined by quantitative polymerase chain reaction, compared with other surveyed fields. Ordinal logistic regression identified positive correlations between SDS and slope, June NDVI, and May maximum temperature, but high June maximum temperature hindered SDS. A modeled SDS risk map showed a clear trend of potential disease occurrences across Iowa. Landsat imagery was analyzed similarly, to discuss the ability to utilize higher spatial resolution data. The results demonstrated the great potential of both MODIS and Landsat imagery for SDS field-specific risk assessment. PMID:27070424

  11. ANALYSIS OF HIGH FIELD NON-LINEAR LOSSES ON SRF SURFACES DUE TO SPECIFIC TOPOGRAPHIC ROUGHNESS

    SciTech Connect

    Chen Xu,Charles Reece,Michael Kelley

    2012-07-01

    The high-field performance of SRF cavities will eventually be limited by the realization of fundamental material limits, whether it is Hc1 or Hsh, or some derivative thereof, at which the superconductivity is lost. Before reaching this fundamental field limit at the macro level, it must be encountered at localized, perhaps microscopic, sites of field enhancement due to local topography. If such sites are small enough, they may produce thermally stabilized normal-conducting regions which contribute non-linear losses when viewed from the macro resonant field perspective, and thus produce degradation in Q0. We have undertaken a calculation of local surface magnetic field enhancement from specific fine topographic structure by conformal mapping method and numerically. A solution of the resulting normal conducting volume has been derived and the corresponding RF Ohmic loss simulated.

  12. 40 CFR 86.1375-2007 - Equipment specifications for field testing.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 20 2012-07-01 2012-07-01 false Equipment specifications for field testing. 86.1375-2007 Section 86.1375-2007 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES (CONTINUED) Emission Regulations for New...

  13. Field Operations and Enforcement Manual for Air Pollution Control. Volume III: Inspection Procedures for Specific Industries.

    ERIC Educational Resources Information Center

    Weisburd, Melvin I.

    The Field Operations and Enforcement Manual for Air Pollution Control, Volume III, explains in detail the following: inspection procedures for specific sources, kraft pulp mills, animal rendering, steel mill furnaces, coking operations, petroleum refineries, chemical plants, non-ferrous smelting and refining, foundries, cement plants, aluminum…

  14. Influence of size distribution and field amplitude on specific loss power

    NASA Astrophysics Data System (ADS)

    Boskovic, M.; Goya, G. F.; Vranjes-Djuric, S.; Jovic, N.; Jancar, B.; Antic, B.

    2015-03-01

    Herein we present the results of specific loss power (SLP) analysis of polydisperse water based ferrofluids, Fe3O4/PEG200 and Fe3O4/PEG6000, with average Fe3O4 particle size of 9 nm and 11 nm, respectively. Specific loss power was measured in alternating magnetic field of various amplitudes and at fixed frequency of 580.5 kHz. Maximum SLP values acquired were 195 W/g for Fe3O4/PEG200 and 60 W/g for Fe3O4/PEG6000 samples. The samples were labeled as superparamagnetic by magnetization measurements, but SLP field dependence showed deviation from the behavior predicted by the commonly employed linear response theory. The scope of this theory for both samples with wide particle size distribution is discussed. Deviation from the expected behavior is explained by referring to polydisperse nature of the samples and field dependent relaxation rates.

  15. Anisotropic Specific Heat of CoNb2O6 in Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Hanawa, Takeshi; Shinkawa, Kohtaro; Ishikawa, Masayasu; Miyatani, Kazuo; Saito, Kazuhiro; Kohn, Kay

    1994-07-01

    We investigated the successive magnetic phase transitions of CoNb2O6 at 2.9 K and 1.9 K by measuring the specific heat, magnetic susceptibility and magnetization of poly- and single-crystalline samples. The specific heat measurements performed in external magnetic fields up to about 1.5 kOe disclosed the Ising-like nature of the transitions and tremendous anisotropic magnetic-field dependence due to the low-dimensional character. Moreover, the specific heat and ac magnetic susceptibility data imply another magnetic state below 1 K. These consequences suggest a very interesting magnetic phase diagram, resulting from the competing single-ion anisotropy and exchange interactions in this compound.

  16. Specific absorption rate and electric field measurements in the near field of six mobile phone base station antennas.

    PubMed

    Toivonen, Tommi; Toivo, Tim; Puranen, Lauri; Jokela, Kari

    2009-05-01

    In this article, the exposure to radio frequency electromagnetic fields was studied in close proximity (distances of 10, 100, 300, and 600 mm) to six base station antennas. The specific absorption rate (SAR) in 800 mm x 500 mm x 200 mm box phantom as well as unperturbed electric field (E) in air was measured. The results were used to determine whether the measurement of local maximum of unperturbed electric field can be used as a compliance check for local exposure. Also, the conservativeness of this assessment method compared to the ICNIRP basic restriction was studied. Moreover, the assessment of whole-body exposure was discussed and the distance ranges presented in which the ICNIRP limit for local exposure could be exceeded before the limit for whole-body SAR. These results show that the electric field measurement alone can be used for easy compliance check for the local exposure at all distances and for all antenna types studied. However, in some cases when the local peak value of E was compared directly to the ICNIRP reference level for unperturbed E, the exposure was overestimated only very slightly (by factor 1.1) compared to the basic restriction for localized SAR in a human, and hence these results can not be generalized to all antenna types. Moreover, it was shown that the limit for localized exposure could be exceeded before the limit for the whole-body average SAR, if the distance to the antenna was less than 240 mm. PMID:19194889

  17. The role of specific humidity fields in the diagnosis of stratosphere troposphere exchange

    SciTech Connect

    Gray, L.J.; Bithell, M.; Cox, B.D.

    1994-09-01

    METEOSAT 4 satellite observations of water vapor show evidence of a rich spectrum of fine scale structure that may be indicative of the transfer of dry, ozone-rich air from the stratosphere deep into the troposphere (Appenzeller and Davies, 1992). The extent to which air within stratospheric intrusions is irreversibly mixed and remains in the troposphere is of considerable current interest, particularly in respect of pollution effects of increasing numbers of subsonic and supersonic aircraft flights that traverse the lower stratosphere. We diagnose potential vorticity and the corresponding distributions of specific humidity from a numerical weather forecast model and show that the latter field displays many of the characteristics of the Meteosat data. Specific humidity fields on both a pressure surface which corresponds approximately to the Meteosat data sampling and on an isentropic surface are compared. We show the presence of streamer-like features in specific humidity that are not evident in the PV fields. We also note the prediliction for the streamers to break off, be advected by the flow and to subsequently become `attached` to other features. Care is therefore required in the interpretation of the Meteosat data for stratosphere troposphere exchange studies. Nevertheless, we suggest that the importance of specific humidity as an indicator of the dynamical evolution of upper level atmospheric flow has previously been overlooked.

  18. Magnetic Field Dependence of the Specific Heat of CuGeO_3

    NASA Astrophysics Data System (ADS)

    Brill, J. W.; Kuo, Y.-K.; Powell, D. K.

    1996-03-01

    In previous work,(Y.K. Kuo, et al. al), Solid State Commun. \\underline94, 385 (1995). we showed that the specific heat anomaly of CuGeO3 at its T_c=14 K spin-Peierls transition was surprisingly close to mean-field in magnitude, but that at lower temperatures the excess specific heat (Δc ≡ cP - βT^3) greatly exceeded its mean-field value. We have now measured the magnetic field (B<7T) dependence of cP in the low field, diamagnetic, dimerized state using ac (f ≈ 30 Hz) calorimetry.^1 We find that Δc(T/T_c(B),B) ≈ Δc(T/T_c(0),0) this field dependence is at least 3 times weaker than expected from the Zeeman splitting of the triplet magnon excitations,(O. Fujita, et al. al), Phys. Rev. Lett. \\underline74, 1677 (1995). suggesting that changes in thermal occupation of Sz = ±1 magnons (at τ ≈ 5 ms) is suppressed. *Supported in part by NSF Grants EHR-9108764 and DMR-9300507.

  19. Present knowledge about specific absorption rates inside a human body exposed to radiofrequency electromagnetic fields

    SciTech Connect

    Garn, J.; Gabriel, C.

    1995-02-01

    We have compiled results of scientific investigations about the relationship between external field-strengths and specific absorption rates inside the human body. The data were normalized to SAR-values that form the basis for current safety standards. Results were compared to exposure limits given in these standard. This comparison should serve as a reference for the selection of reliable reference levels for personal protection against thermal effects in radiofrequency electromagnetic fields. The need to measure and monitor ankle/wrist currents to protect some exposed workers is explained. The study has also highlighted a scarcity of dosimetric data at frequencies below 3 MHz. 20 refs., 7 figs.

  20. Targeted treatment of cancer with radiofrequency electromagnetic fields amplitude-modulated at tumor-specific frequencies

    PubMed Central

    Zimmerman, Jacquelyn W.; Jimenez, Hugo; Pennison, Michael J.; Brezovich, Ivan; Morgan, Desiree; Mudry, Albert; Costa, Frederico P.; Barbault, Alexandre; Pasche, Boris

    2013-01-01

    In the past century, there have been many attempts to treat cancer with low levels of electric and magnetic fields. We have developed noninvasive biofeedback examination devices and techniques and discovered that patients with the same tumor type exhibit biofeedback responses to the same, precise frequencies. Intrabuccal administration of 27.12 MHz radiofrequency (RF) electromagnetic fields (EMF), which are amplitude-modulated at tumor-specific frequencies, results in long-term objective responses in patients with cancer and is not associated with any significant adverse effects. Intrabuccal administration allows for therapeutic delivery of very low and safe levels of EMF throughout the body as exemplified by responses observed in the femur, liver, adrenal glands, and lungs. In vitro studies have demonstrated that tumor-specific frequencies identified in patients with various forms of cancer are capable of blocking the growth of tumor cells in a tissue- and tumor-specific fashion. Current experimental evidence suggests that tumor-specific modulation frequencies regulate the expression of genes involved in migration and invasion and disrupt the mitotic spindle. This novel targeted treatment approach is emerging as an appealing therapeutic option for patients with advanced cancer given its excellent tolerability. Dissection of the molecular mechanisms accounting for the anti-cancer effects of tumor-specific modulation frequencies is likely to lead to the discovery of novel pathways in cancer. PMID:24206915

  1. Experimental and computational investigation of the patient-specific abdominal aortic aneurysm pressure field.

    PubMed

    Antón, R; Chen, C-Y; Hung, M-Y; Finol, E A; Pekkan, K

    2015-07-01

    The objective of the present manuscript is three-fold: (i) to study the detailed pressure field inside a patient-specific abdominal aortic aneurysm (AAA) model experimentally and numerically and discuss its clinical relevance, (ii) to validate a number of possible numerical model options and their ability to predict the experimental pressure field and (iii) to compare the spatial pressure drop in the AAA before and after the formation of intraluminal thrombus (ILT) for a late disease development timeline. A finite volume method was used to solve the governing equations of fluid flow to simulate the flow dynamics in a numerical model of the AAA. Following our patient-specific anatomical rapid prototyping technique, physical models of the aneurysm were created with seven ports for pressure measurement along the blood flow path. A flow loop operating with a blood analogue fluid was used to replicate the patient-specific flow conditions, acquired with phase-contrast magnetic resonance imaging, and measure pressure in the flow model. The Navier-Stokes equations and two turbulent models were implemented numerically to compare the pressure estimations with experimental measurements. The relative pressure difference from experiments obtained with the best performing model (unsteady laminar simulation) was ∼1.1% for the AAA model without ILT and ∼15.4% for the AAA model with ILT (using Reynolds Stress Model). Future investigations should include validation of the 3D velocity field and wall shear stresses within the AAA sac predicted by the three numerical models. PMID:24460046

  2. A low specific on-resistance SOI LDMOS with a novel junction field plate

    NASA Astrophysics Data System (ADS)

    Luo, Yin-Chun; Luo, Xiao-Rong; Hu, Gang-Yi; Fan, Yuan-Hang; Li, Peng-Cheng; Wei, Jie; Tan, Qiao; Zhang, Bo

    2014-07-01

    A low specific on-resistance SOI LDMOS with a novel junction field plate (JFP) is proposed and investigated theoretically. The most significant feature of the JFP LDMOS is a PP—N junction field plate instead of a metal field plate. The unique structure not only yields charge compensation between the JFP and the drift region, but also modulates the surface electric field. In addition, a trench gate extends to the buried oxide layer (BOX) and thus widens the vertical conduction area. As a result, the breakdown voltage (BV) is improved and the specific on-resistance (Ron,sp) is decreased significantly. It is demonstrated that the BV of 306 V and the Ron,sp of 7.43 mΩ·cm2 are obtained for the JFP LDMOS. Compared with those of the conventional LDMOS with the same dimensional parameters, the BV is improved by 34.8%, and the Ron,sp is decreased by 56.6% simultaneously. The proposed JFP LDMOS exhibits significant superiority in terms of the trade-off between BV and Ron,sp. The novel JFP technique offers an alternative technique to achieve high blocking voltage and large current capacity for power devices.

  3. Specifications and Martin boundaries for P(Φ)2-random fields

    NASA Astrophysics Data System (ADS)

    Röckner, Michael

    1986-03-01

    It is shown that P(Φ)2-Gibbs states in the sense of Guerra, Rosen and Simon are given by a specification. The construction of the specification is based on finding a proper version of the interaction density given by the polynomial P. The existence of this version follows from the fact that all powers of the solution of a Dirichlet problem for an open bounded set U with boundary data given by a distribution are integrable on U. As a consequence the Martin boundary theory for specifications can be applied to P(Φ)2-random fields. It follows that any P(Φ)2-Gibbs state can be represented in terms of extreme Gibbs states. In certain cases the extreme Gibbs states are characterized in terms of harmonic functions. It follows, in particular, that for any given boundary condition introduced so far the associated cutoff P(Φ)2-measure has a representation as an integral over harmonic functions.

  4. Reference field specification and preliminary beam selection strategy for accelerator-based GCR simulation.

    PubMed

    Slaba, Tony C; Blattnig, Steve R; Norbury, John W; Rusek, Adam; La Tessa, Chiara

    2016-02-01

    The galactic cosmic ray (GCR) simulator at the NASA Space Radiation Laboratory (NSRL) is intended to deliver the broad spectrum of particles and energies encountered in deep space to biological targets in a controlled laboratory setting. In this work, certain aspects of simulating the GCR environment in the laboratory are discussed. Reference field specification and beam selection strategies at NSRL are the main focus, but the analysis presented herein may be modified for other facilities and possible biological considerations. First, comparisons are made between direct simulation of the external, free space GCR field and simulation of the induced tissue field behind shielding. It is found that upper energy constraints at NSRL limit the ability to simulate the external, free space field directly (i.e. shielding placed in the beam line in front of a biological target and exposed to a free space spectrum). Second, variation in the induced tissue field associated with shielding configuration and solar activity is addressed. It is found that the observed variation is likely within the uncertainty associated with representing any GCR reference field with discrete ion beams in the laboratory, given current facility constraints. A single reference field for deep space missions is subsequently identified. Third, a preliminary approach for selecting beams at NSRL to simulate the designated reference field is presented. This approach is not a final design for the GCR simulator, but rather a single step within a broader design strategy. It is shown that the beam selection methodology is tied directly to the reference environment, allows facility constraints to be incorporated, and may be adjusted to account for additional constraints imposed by biological or animal care considerations. The major biology questions are not addressed herein but are discussed in a companion paper published in the present issue of this journal. Drawbacks of the proposed methodology are discussed

  5. Reference field specification and preliminary beam selection strategy for accelerator-based GCR simulation

    NASA Astrophysics Data System (ADS)

    Slaba, Tony C.; Blattnig, Steve R.; Norbury, John W.; Rusek, Adam; La Tessa, Chiara

    2016-02-01

    The galactic cosmic ray (GCR) simulator at the NASA Space Radiation Laboratory (NSRL) is intended to deliver the broad spectrum of particles and energies encountered in deep space to biological targets in a controlled laboratory setting. In this work, certain aspects of simulating the GCR environment in the laboratory are discussed. Reference field specification and beam selection strategies at NSRL are the main focus, but the analysis presented herein may be modified for other facilities and possible biological considerations. First, comparisons are made between direct simulation of the external, free space GCR field and simulation of the induced tissue field behind shielding. It is found that upper energy constraints at NSRL limit the ability to simulate the external, free space field directly (i.e. shielding placed in the beam line in front of a biological target and exposed to a free space spectrum). Second, variation in the induced tissue field associated with shielding configuration and solar activity is addressed. It is found that the observed variation is likely within the uncertainty associated with representing any GCR reference field with discrete ion beams in the laboratory, given current facility constraints. A single reference field for deep space missions is subsequently identified. Third, a preliminary approach for selecting beams at NSRL to simulate the designated reference field is presented. This approach is not a final design for the GCR simulator, but rather a single step within a broader design strategy. It is shown that the beam selection methodology is tied directly to the reference environment, allows facility constraints to be incorporated, and may be adjusted to account for additional constraints imposed by biological or animal care considerations. The major biology questions are not addressed herein but are discussed in a companion paper published in the present issue of this journal. Drawbacks of the proposed methodology are discussed

  6. Recommendations for Guidelines for Environment-Specific Magnetic-Field Measurements, Rapid Program Engineering Project #2

    SciTech Connect

    Electric Research and Management, Inc.; IIT Research Institute; Magnetic Measurements; Survey Research Center, University of California; T. Dan Bracken, Inc.

    1997-03-11

    The purpose of this project was to document widely applicable methods for characterizing the magnetic fields in a given environment, recognizing the many sources co-existing within that space. The guidelines are designed to allow the reader to follow an efficient process to (1) plan the goals and requirements of a magnetic-field study, (2) develop a study structure and protocol, and (3) document and carry out the plan. These guidelines take the reader first through the process of developing a basic study strategy, then through planning and performing the data collection. Last, the critical factors of data management, analysis reporting, and quality assurance are discussed. The guidelines are structured to allow the researcher to develop a protocol that responds to specific site and project needs. The Research and Public Information Dissemination Program (RAPID) is based on exposure to magnetic fields and the potential health effects. Therefore, the most important focus for these magnetic-field measurement guidelines is relevance to exposure. The assumed objective of an environment-specific measurement is to characterize the environment (given a set of occupants and magnetic-field sources) so that information about the exposure of the occupants may be inferred. Ideally, the researcher seeks to obtain complete or "perfect" information about these magnetic fields, so that personal exposure might also be modeled perfectly. However, complete data collection is not feasible. In fact, it has been made more difficult as the research field has moved to expand the list of field parameters measured, increasing the cost and complexity of performing a measurement and analyzing the data. The guidelines address this issue by guiding the user to design a measurement protocol that will gather the most exposure-relevant information based on the locations of people in relation to the sources. We suggest that the "microenvironment" become the base unit of area in a study, with

  7. High-k Dielectric Passivation: Novel Considerations Enabling Cell Specific Lysis Induced by Electric Fields.

    PubMed

    Wassermann, Klemens J; Barth, Sven; Keplinger, Franz; Noehammer, Christa; Peham, Johannes R

    2016-08-24

    A better understanding of the electrodynamic behavior of cells interacting with electric fields would allow for novel scientific insights and would lead to the next generation of cell manipulation, diagnostics, and treatment. Here, we introduce a promising electrode design by using metal oxide high-k dielectric passivation. The thermally generated dielectric passivation layer enables efficient electric field coupling to the fluid sample comprising cells while simultaneously decoupling the electrode ohmically from the electrolyte, allowing for better control and adjustability of electric field effects due to reduced electrochemical reactions at the electrode surface. This approach demonstrates cell-size specific lysis with electric fields in a microfluidic flow-through design resulting in 99.8% blood cell lysis at 6 s exposure without affecting the viability of Gram-positive and Gram-negative bacterial spike-ins. The advantages of this new approach can support next-generation investigations of electrodynamics in biological systems and their exploitation for cell manipulation in multiple fields of medicine, life science, and industry. PMID:27466697

  8. Soil specific re-calibration of water content sensors for a field-scale sensor network

    NASA Astrophysics Data System (ADS)

    Gasch, Caley K.; Brown, David J.; Anderson, Todd; Brooks, Erin S.; Yourek, Matt A.

    2015-04-01

    Obtaining accurate soil moisture data from a sensor network requires sensor calibration. Soil moisture sensors are factory calibrated, but multiple site specific factors may contribute to sensor inaccuracies. Thus, sensors should be calibrated for the specific soil type and conditions in which they will be installed. Lab calibration of a large number of sensors prior to installation in a heterogeneous setting may not be feasible, and it may not reflect the actual performance of the installed sensor. We investigated a multi-step approach to retroactively re-calibrate sensor water content data from the dielectric permittivity readings obtained by sensors in the field. We used water content data collected since 2009 from a sensor network installed at 42 locations and 5 depths (210 sensors total) within the 37-ha Cook Agronomy Farm with highly variable soils located in the Palouse region of the Northwest United States. First, volumetric water content was calculated from sensor dielectric readings using three equations: (1) a factory calibration using the Topp equation; (2) a custom calibration obtained empirically from an instrumented soil in the field; and (3) a hybrid equation that combines the Topp and custom equations. Second, we used soil physical properties (particle size and bulk density) and pedotransfer functions to estimate water content at saturation, field capacity, and wilting point for each installation location and depth. We also extracted the same reference points from the sensor readings, when available. Using these reference points, we re-scaled the sensor readings, such that water content was restricted to the range of values that we would expect given the physical properties of the soil. The re-calibration accuracy was assessed with volumetric water content measurements obtained from field-sampled cores taken on multiple dates. In general, the re-calibration was most accurate when all three reference points (saturation, field capacity, and wilting

  9. A graphene field-effect transistor as a molecule-specific probe of DNA nucleobases.

    PubMed

    Dontschuk, Nikolai; Stacey, Alastair; Tadich, Anton; Rietwyk, Kevin J; Schenk, Alex; Edmonds, Mark T; Shimoni, Olga; Pakes, Chris I; Prawer, Steven; Cervenka, Jiri

    2015-01-01

    Fast and reliable DNA sequencing is a long-standing target in biomedical research. Recent advances in graphene-based electrical sensors have demonstrated their unprecedented sensitivity to adsorbed molecules, which holds great promise for label-free DNA sequencing technology. To date, the proposed sequencing approaches rely on the ability of graphene electric devices to probe molecular-specific interactions with a graphene surface. Here we experimentally demonstrate the use of graphene field-effect transistors (GFETs) as probes of the presence of a layer of individual DNA nucleobases adsorbed on the graphene surface. We show that GFETs are able to measure distinct coverage-dependent conductance signatures upon adsorption of the four different DNA nucleobases; a result that can be attributed to the formation of an interface dipole field. Comparison between experimental GFET results and synchrotron-based material analysis allowed prediction of the ultimate device sensitivity, and assessment of the feasibility of single nucleobase sensing with graphene. PMID:25800494

  10. Accurate Structure Prediction and Conformational Analysis of Cyclic Peptides with Residue-Specific Force Fields.

    PubMed

    Geng, Hao; Jiang, Fan; Wu, Yun-Dong

    2016-05-19

    Cyclic peptides (CPs) are promising candidates for drugs, chemical biology tools, and self-assembling nanomaterials. However, the development of reliable and accurate computational methods for their structure prediction has been challenging. Here, 20 all-trans CPs of 5-12 residues selected from Cambridge Structure Database have been simulated using replica-exchange molecular dynamics with four different force fields. Our recently developed residue-specific force fields RSFF1 and RSFF2 can correctly identify the crystal-like conformations of more than half CPs as the most populated conformation. The RSFF2 performs the best, which consistently predicts the crystal structures of 17 out of 20 CPs with rmsd < 1.1 Å. We also compared the backbone (ϕ, ψ) sampling of residues in CPs with those in short linear peptides and in globular proteins. In general, unlike linear peptides, CPs have local conformational free energies and entropies quite similar to globular proteins. PMID:27128113

  11. A graphene field-effect transistor as a molecule-specific probe of DNA nucleobases

    NASA Astrophysics Data System (ADS)

    Dontschuk, Nikolai; Stacey, Alastair; Tadich, Anton; Rietwyk, Kevin J.; Schenk, Alex; Edmonds, Mark T.; Shimoni, Olga; Pakes, Chris I.; Prawer, Steven; Cervenka, Jiri

    2015-03-01

    Fast and reliable DNA sequencing is a long-standing target in biomedical research. Recent advances in graphene-based electrical sensors have demonstrated their unprecedented sensitivity to adsorbed molecules, which holds great promise for label-free DNA sequencing technology. To date, the proposed sequencing approaches rely on the ability of graphene electric devices to probe molecular-specific interactions with a graphene surface. Here we experimentally demonstrate the use of graphene field-effect transistors (GFETs) as probes of the presence of a layer of individual DNA nucleobases adsorbed on the graphene surface. We show that GFETs are able to measure distinct coverage-dependent conductance signatures upon adsorption of the four different DNA nucleobases; a result that can be attributed to the formation of an interface dipole field. Comparison between experimental GFET results and synchrotron-based material analysis allowed prediction of the ultimate device sensitivity, and assessment of the feasibility of single nucleobase sensing with graphene.

  12. Specific heating power of fatty acid and phospholipid stabilized magnetic fluids in an alternating magnetic field

    NASA Astrophysics Data System (ADS)

    DeCuyper, M.; Hodenius, M.; Ivanova, G.; Baumann, M.; Paciok, E.; Eckert, T.; Soenen, S. J. H.; Schmitz-Rode, T.

    2008-05-01

    Magnetic fluids (MFs) with a similar narrow size distribution of the iron oxide core were stabilized with lauric acid (MF 1), oleate (MF 2) or, after dialysis in the presence of liposomes, with phospholipid molecules (MF 3 and MF 4, respectively). The hydrodynamic sizes of the MF 1 and MF 3 were half those found for MF 2 and MF 4. The MFs were exposed to inductive heating in an alternating magnetic field at a frequency of 200 kHz and a maximum magnetic field strength of 3.8 kA m-1. Specific absorption rates (SAR) of 294 ± 42 (MF 1), 214 ± 16 (MF 2), 297 ± 13 (MF 3) and 213 ± 6 W g-1 Fe (MF 4) were obtained. The data for MF 2 and MF 4 were identical to those found for the commercially available ferucarbotran. The biomedical relevance of the phospholipid-coated MFs is briefly discussed.

  13. Generality with specificity: the dynamic field theory generalizes across tasks and time scales

    PubMed Central

    Simmering, Vanessa R.; Spencer, John P.

    2008-01-01

    A central goal in cognitive and developmental science is to develop models of behavior that can generalize across both tasks and development while maintaining a commitment to detailed behavioral prediction. This paper presents tests of one such model, the Dynamic Field Theory (DFT). The DFT was originally proposed to capture delay-dependent biases in spatial recall and developmental changes in spatial recall performance. More recently, the theory was generalized to adults’ performance in a second spatial working memory task, position discrimination. Here we use the theory to predict a specific, complex developmental pattern in position discrimination. Data with 3- to 6-year-old children and adults confirm these predictions, demonstrating that the DFT achieves generality across tasks and time scales, as well as the specificity necessary to generate novel, falsifiable predictions. PMID:18576962

  14. Specific features of the behavior of electroarc CuO nanoparticles in a magnetic field

    NASA Astrophysics Data System (ADS)

    Ushakov, A. V.; Karpov, I. V.; Lepeshev, A. A.; Petrov, M. I.; Fedorov, L. Yu.

    2015-05-01

    The temperature and time dependences of the magnetization of copper oxide nanoparticles 8, 13, and 18 nm in size have been investigated. Specific features of the behavior of CuO nanoparticles formed by vacuum plasma-arc synthesis as compared to other antiferromagnetic particles have been revealed. It has been shown that the bifurcation of magnetization curves upon cooling in the zero (ZFC) and nonzero (FC) magnetic fields occurs above the Néel temperature, while the usual peak of the magnetization curve is absent in the ZFC mode. The problems associated with the nonequilibrium behavior of synthesized CuO nanoparticles have been discussed.

  15. Comparing intra- and inter-specific effects on litter decomposition in an old-field ecosystem

    SciTech Connect

    Crutsinger, Greg; Sanders, Dr. Nathan James; Classen, Aimee T

    2009-09-01

    Plant species can differ in the quantity and quality of leaf litter they produce, and many studies have examined whether plant species diversity affects leaf-litter decomposition and nutrient release. A growing number of studies have indicated that intra-specific variation within plant species can also affect key ecosystem processes. However, the relative importance of intra- versus inter-specific variation for the functioning of ecosystems remains poorly known. Here, we investigate the effects of intra-specific variation in a dominant old-field plant species, tall goldenrod (Solidago altissima), and inter-specific variation among goldenrod species on litter quality, decomposition, and nitrogen (N) release. We found that the nutrient concentration of leaf litter varied among genotypes, which translated into 50% difference in decomposition rates. Variation among other goldenrod species in decomposition rate was more than twice that of genetic variation within S. altissima. Furthermore, by manipulating litterbags to contain 1, 3, 6, or 9 genotypes, we found that S. altissima genotype identity had much stronger effects than did genotypic diversity on leaf-litter quality, decomposition, and N release. Taken together, these results suggest that the order of ecological importance for controlling leaf-litter decomposition and N release dynamics is plant species identitygenotype identity>genotypic diversity.

  16. Genus-Specific Primers for Study of Fusarium Communities in Field Samples

    PubMed Central

    Edel-Hermann, Véronique; Gautheron, Nadine; Durling, Mikael Brandström; Kolseth, Anna-Karin; Steinberg, Christian; Persson, Paula; Friberg, Hanna

    2015-01-01

    Fusarium is a large and diverse genus of fungi of great agricultural and economic importance, containing many plant pathogens and mycotoxin producers. To date, high-throughput sequencing of Fusarium communities has been limited by the lack of genus-specific primers targeting regions with high discriminatory power at the species level. In the present study, we evaluated two Fusarium-specific primer pairs targeting translation elongation factor 1 (TEF1). We also present the new primer pair Fa+7/Ra+6. Mock Fusarium communities reflecting phylogenetic diversity were used to evaluate the accuracy of the primers in reflecting the relative abundance of the species. TEF1 amplicons were subjected to 454 high-throughput sequencing to characterize Fusarium communities. Field samples from soil and wheat kernels were included to test the method on more-complex material. For kernel samples, a single PCR was sufficient, while for soil samples, nested PCR was necessary. The newly developed primer pairs Fa+7/Ra+6 and Fa/Ra accurately reflected Fusarium species composition in mock DNA communities. In field samples, 47 Fusarium operational taxonomic units were identified, with the highest Fusarium diversity in soil. The Fusarium community in soil was dominated by members of the Fusarium incarnatum-Fusarium equiseti species complex, contradicting findings in previous studies. The method was successfully applied to analyze Fusarium communities in soil and plant material and can facilitate further studies of Fusarium ecology. PMID:26519387

  17. Compound specific isotope analysis to investigate pesticide degradation in lysimeter experiments at field conditions

    NASA Astrophysics Data System (ADS)

    Ryabenko, Evgenia; Elsner, Martin; Bakkour, Rani; Hofstetter, Thomas; Torrento, Clara; Hunkeler, Daniel

    2015-04-01

    The frequent detection of organic micropollutants such as pesticides, consumer care products or pharmaceuticals in water is an increasing concern for human and ecosystem health. Degradation analysis of these compounds can be challenging in complex systems due to the fact that metabolites are not always found and mass balances frequently cannot be closed. Many abiotic and biotic degradation pathways cause, however, distinct isotope fractionation, where light isotopes are transferred preferentially from the reactant to the product pool (normal isotope fractionation). Compound-specific isotope analysis (CSIA) of multiple elements is a particularly powerful method to evaluate organic micropollutant transformation, because it can even give pathway-specific isotope fractionation (1,2). Available CSIA field studies, however, have focused almost exclusively on volatile petroleum and chlorinated hydrocarbons, which are present in high concentrations in the environment and can be extracted easily from water for GC-IRMS analysis. In the case of micropollutants, such as pesticides, CSIA in more challenging since it needs to be conducted at lower concentrations and requires pre-concentration, purification and high chromatographic performance (3). In this study we used lysimeters experiments to analyze transformation of atrazine, acetochlor, metolachlor and chloridazone by studying associated isotope fractionation. The project combines a) analytical method development for CSIA, b) identification of pathways of micropollutant degradation and c) quantification of transformation processes under field condition. The pesticides were applied both, at the soil surface and below the top soil under field-relevant concentrations in May 2014. After typical irrigation of the lysimeters, seepage water was collected in 50L bottles and stored for further SPE and CSIA. Here we present the very first result of a) analytical method development, b) improvement of SPE methods for complex pesticide

  18. Retesting The Validity Of A Specific Field Test For Judo Training

    PubMed Central

    Santos, Luis; González, Vicente; Iscar, Marta; Brime, Juan I.; Fernández-Río, Javier; Rodríguez, Blanca; Montoliu, Mª Ángeles

    2011-01-01

    The main goal of this research project was to retest the validity of a specifically designed judo field test (Santos Test) in a different group of judokas. Eight (n=8) national-level male judokas underwent laboratory and field testing. The mean data (mean +/− SD) obtained in the laboratory tests was: HRmax: 200 ± 4.0 beats × min−1, VO2 max: 52.8 ± 7.9 ± ml × kg−1 × min−1, lactate max: 12 ± 2.5 mmol × l−1, HR at the anaerobic threshold: 174.2 ± 9.4 beats × min−1, percentage of maximum heart rate at which the anaerobic threshold appears: 87 ± 3.6 %, lactate threshold: 4.0 ± 0.2 mmol × l−1, and RPE: 17.2 ± 1.0. The mean data obtained in the field test (Santos) was: HRmax: 201.3 ± 4.1 beats × min−1, VO2 max: 55.6 ± 5.8 ml × kg−1 × min−1, lactate max: 15.6 ± 2.8 mmol × l−1, HR at the anaerobic threshold: 173.2 ± 4.3 beats × min−1, percentage of maximum heart rate at which the anaerobic threshold appears: 86 ± 2.5 %, lactate threshold: 4.0 ± 0.2 mmol × l−1, and RPE: 16.7 ± 1.0. There were no significant differences between the data obtained on both tests in any of the parameters, except for maximum lactate concentration. Therefore, the Santos test can be considered a valid tool specific for judo training. PMID:23486994

  19. Topographic Distribution of Stimulus-Specific Adaptation across Auditory Cortical Fields in the Anesthetized Rat

    PubMed Central

    Nieto-Diego, Javier; Malmierca, Manuel S.

    2016-01-01

    Stimulus-specific adaptation (SSA) in single neurons of the auditory cortex was suggested to be a potential neural correlate of the mismatch negativity (MMN), a widely studied component of the auditory event-related potentials (ERP) that is elicited by changes in the auditory environment. However, several aspects on this SSA/MMN relation remain unresolved. SSA occurs in the primary auditory cortex (A1), but detailed studies on SSA beyond A1 are lacking. To study the topographic organization of SSA, we mapped the whole rat auditory cortex with multiunit activity recordings, using an oddball paradigm. We demonstrate that SSA occurs outside A1 and differs between primary and nonprimary cortical fields. In particular, SSA is much stronger and develops faster in the nonprimary than in the primary fields, paralleling the organization of subcortical SSA. Importantly, strong SSA is present in the nonprimary auditory cortex within the latency range of the MMN in the rat and correlates with an MMN-like difference wave in the simultaneously recorded local field potentials (LFP). We present new and strong evidence linking SSA at the cellular level to the MMN, a central tool in cognitive and clinical neuroscience. PMID:26950883

  20. Anisotropic polymer composites synthesized by immobilizing cellulose nanocrystal suspensions specifically oriented under magnetic fields.

    PubMed

    Tatsumi, Mio; Kimura, Fumiko; Kimura, Tsunehisa; Teramoto, Yoshikuni; Nishio, Yoshiyuki

    2014-12-01

    Novel polymer composites reinforced with an oriented cellulose nanocrystal (CNC) assembly were prepared from suspensions of CNC in aqueous 2-hydroxyethyl methacrylate (HEMA) via magnetic field application to the suspensions followed by polymerization treatment. The starting suspensions used at ∼6 wt % CNC separated into an upper isotropic phase and a lower anisotropic (chiral nematic) one in the course of quiescent standing. A static or rotational magnetic field was applied to the isolated isotropic and anisotropic phases. UV-induced polymerization of HEMA perpetuated the respective states of magnetic orientation invested for the CNC dispersions to yield variously oriented CNC/poly(2-hydroxyethyl methacrylate) composites. The structural characterization was carried out by use of X-ray diffractometry and optical and scanning electron microscopy. The result indicated that CNCs were aligned in the composites distinctively according to the static or rotational magnetic application when the anisotropic phases were used, whereas such a specific CNC orientation was not appreciable when the isotropic phases were sampled. This marks out effectiveness of a coherent response of CNCs in the mesomorphic assembly. In dynamic mechanical experiments in tensile or compressive mode, we observed a clear mechanical anisotropy for the polymer composites synthesized from wholly anisotropic suspensions under static or rotational magnetization. The higher modulus (in compression) was detected for a composite reinforced by locking-in the uniaxial CNC alignment attainable through conversion of the initial chiral nematic phase into a nematic phase in the rotational magnetic field. PMID:25390070

  1. Demonstration Using Field Collections that Argentina Fall Armyworm Populations Exhibit Strain-specific Host Plant Preferences.

    PubMed

    Murúa, M Gabriela; Nagoshi, Rodney N; Dos Santos, Daniel A; Hay-Roe, Mirian M; Meagher, Robert L; Vilardi, J C

    2015-10-01

    Spodoptera frugiperda, the fall armyworm, is a major economic pest throughout the Western Hemisphere of corn (maize), cotton, sorghum, and a variety of agricultural grasses and vegetable crops. Studies in the United States, the Caribbean, and Brazil demonstrated the existence of two subpopulations (previously designated "host strains") that differ in their choice of plant host. Specifically, the corn strain is preferentially found in corn and sorghum, while the rice strain is dominant in rice, turf grass, and alfalfa. However, inconsistent results were reported in surveys of fall armyworm in Argentina, with some indicating that the host plant preferences of the two strains might be compromised or even nonexistent. If correct, this would complicate efforts to control this pest by considerably expanding the range of habitats that would have to be considered as potential sources for fall armyworm infestations in specific crops. A reexamination of Argentine fall armyworm, this time with field collections rather than the laboratory colonies used in previous studies, confirmed the existence of the two strains and their host preferences. Specifically, the corn strain was consistently the majority population infesting corn and was usually so in sorghum, while the rice strain was predominant in pasture/turf grasses and alfalfa. The one outlier was a collection from rice, which had a corn strain majority. Overall, the data were generally consistent with strain behaviors observed in other areas of the Western Hemisphere. PMID:26453719

  2. Specific identification of coconut tinangaja viroid for differential field diagnosis of viroids in coconut palm.

    PubMed

    Hodgson, R A; Wall, G C; Randles, J W

    1998-08-01

    ABSTRACT Tinangaja is a widespread lethal disease of putative viroid etiology affecting coconut palm on the island of Guam. Determination of its distribution and mode of spread requires a simple and reliable diagnostic procedure that is specific for the associated coconut tinangaja viroid (CTiVd). A method of extracting tissue followed by analytical agarose gel electrophoresis for CTiVd detection has been developed and used to identify the viroid in leaf samples of suspect symptomatic palms growing in the field. Two-dimensional polyacrylamide gel electrophoresis showed that the viroid band contained circular molecules that are typical for viroids. Confirmation of the identity of CTiVd and detection of low levels of viroid below the threshold of detection by agarose gel electrophoresis was achieved either by diagnostic oligonucleotide-probe (DOP) hybridization assay or by reverse-transcription polymerase chain reaction (RT-PCR) with the oligonucleotide probe as one of the two PCR primers. RT-PCR was not substantially more sensitive than DOP-hybridization assay. This procedure also was applicable to coconut cadang-cadang viroid (CCCVd), and oligonucleotide probes designed to be specific for either CTiVd or CCCVd distinguished between these two viroids in coconut leaf extracts. This strategy provides a rapid and specific indexing procedure for the two characterized viroids of coconut palm and will be applicable to further studies on the viroid-like sequences previously reported in tropical monocotyledons. PMID:18944882

  3. Correction factors for ionization chamber dosimetry in CyberKnife: Machine-specific, plan-class, and clinical fields

    SciTech Connect

    Gago-Arias, Araceli; Antolin, Elena; Fayos-Ferrer, Francisco; Simon, Rocio; Gonzalez-Castano, Diego M.; Palmans, Hugo; Sharpe, Peter; Gomez, Faustino; Pardo-Montero, Juan

    2013-01-15

    Purpose: The aim of this work is the application of the formalism for ionization chamber reference dosimetry of small and nonstandard fields [R. Alfonso, P. Andreo, R. Capote, M. S. Huq, W. Kilby, P. Kjaell, T. R. Mackie, H. Palmans, K. Rosser, J. Seuntjens, W. Ullrich, and S. Vatnitsky, 'A new formalism for reference dosimetry of small and nonstandard fields,' Med. Phys. 35, 5179-5186 (2008)] to the CyberKnife robotic radiosurgery system. Correction factors for intermediate calibration fields, a machine-specific reference field (msr) and two plan-class specific reference fields (pcsr), have been studied. Furthermore, the applicability of the new formalism to clinical dosimetry has been analyzed through the investigation of two clinical treatments. Methods: PTW31014 and Scanditronix-Wellhofer CC13 ionization chamber measurements were performed for the fields under investigation. Absorbed dose to water was determined using alanine reference dosimetry, and experimental correction factors were calculated from alanine to ionization chamber readings ratios. In addition, correction factors were calculated for the intermediate calibration fields and one of the clinical treatment fields using the Monte Carlo method and these were compared with the experimental values. Results: Overall correction factors deviating from unity by approximately 2% were obtained from both measurements and simulations, with values below and above unity for the studied intermediate calibration fields and clinical fields for the ionization chambers under consideration. Monte Carlo simulations yielded correction factors comparable with those obtained from measurements for the machine-specific reference field, although differences from 1% to 3.3% were observed between measured and calculated correction factors for the composite intermediate calibration fields. Dose distribution inhomogeneities are thought to be responsible for such discrepancies. Conclusions: The differences found between overall

  4. Magnetic Nanoparticles with High Specific Absorption Rate at Low Alternating Magnetic Field

    PubMed Central

    Kekalo, K.; Baker, I.; Meyers, R.; Shyong, J.

    2015-01-01

    This paper describes the synthesis and properties of a new type of magnetic nanoparticle (MNP) for use in the hyperthermia treatment of tumors. These particles consist of 2–4 nm crystals of gamma-Fe2O3 gathered in 20–40 nm aggregates with a coating of carboxymethyl-dextran, producing a zetasize of 110–120 nm. Despite their very low saturation magnetization (1.5–6.5 emu/g), the specific absorption rate (SAR) of the nanoparticles is 22–200 W/g at applied alternating magnetic field (AMF) with strengths of 100–500 Oe at a frequency of 160 kHz. PMID:26884816

  5. Specific force field parameters determination for the hybrid ab initio QM/MM LSCF method.

    PubMed

    Ferré, Nicolas; Assfeld, Xavier; Rivail, Jean-Louis

    2002-04-30

    The pure quantum mechanics method, called Local Self-Consistent Field (LSCF), that allows to optimize a wave function within the constraint that some predefined spinorbitals are kept frozen, is discussed. These spinorbitals can be of any shape, and their occupation numbers can be 0 or 1. Any post-Hartree-Fock method, based on the restricted or unrestricted Hartree-Fock Slater determinant, and Kohn-Sham-based DFT method are available. The LSCF method is easily applied to hybrid quantum mechanics/molecular mechanics (QM/MM) procedure where the quantum and the classical parts are covalently bonded. The complete methodology of our hybrid QM/MM scheme is detailed for studies of macromolecular systems. Not only the energy but also the gradients are derived; thus, the full geometry optimization of the whole system is feasible. We show that only specific force field parameters are needed for a correct description of the molecule, they are given for some general chemical bonds. A careful analysis of the errors induced by the use of molecular mechanics in hybrid computation show that a general procedure can be derived to obtain accurate results at low computation effort. The methodology is applied to the structure determination of the crambin protein and to Menshutkin reactions between primary amines and chloromethane. PMID:11939595

  6. Evaluation of Specific Absorption Rate as a Dosimetric Quantity for Electromagnetic Fields Bioeffects

    PubMed Central

    Panagopoulos, Dimitris J.; Johansson, Olle; Carlo, George L.

    2013-01-01

    Purpose To evaluate SAR as a dosimetric quantity for EMF bioeffects, and identify ways for increasing the precision in EMF dosimetry and bioactivity assessment. Methods We discuss the interaction of man-made electromagnetic waves with biological matter and calculate the energy transferred to a single free ion within a cell. We analyze the physics and biology of SAR and evaluate the methods of its estimation. We discuss the experimentally observed non-linearity between electromagnetic exposure and biological effect. Results We find that: a) The energy absorbed by living matter during exposure to environmentally accounted EMFs is normally well below the thermal level. b) All existing methods for SAR estimation, especially those based upon tissue conductivity and internal electric field, have serious deficiencies. c) The only method to estimate SAR without large error is by measuring temperature increases within biological tissue, which normally are negligible for environmental EMF intensities, and thus cannot be measured. Conclusions SAR actually refers to thermal effects, while the vast majority of the recorded biological effects from man-made non-ionizing environmental radiation are non-thermal. Even if SAR could be accurately estimated for a whole tissue, organ, or body, the biological/health effect is determined by tiny amounts of energy/power absorbed by specific biomolecules, which cannot be calculated. Moreover, it depends upon field parameters not taken into account in SAR calculation. Thus, SAR should not be used as the primary dosimetric quantity, but used only as a complementary measure, always reporting the estimating method and the corresponding error. Radiation/field intensity along with additional physical parameters (such as frequency, modulation etc) which can be directly and in any case more accurately measured on the surface of biological tissues, should constitute the primary measure for EMF exposures, in spite of similar uncertainty to predict

  7. Nociceptive Local Field Potentials Recorded from the Human Insula Are Not Specific for Nociception

    PubMed Central

    Liberati, Giulia; Klöcker, Anne; Safronova, Marta M.; Ferrão Santos, Susana; Ribeiro Vaz, Jose-Geraldo; Raftopoulos, Christian; Mouraux, André

    2016-01-01

    The insula, particularly its posterior portion, is often regarded as a primary cortex for pain. However, this interpretation is largely based on reverse inference, and a specific involvement of the insula in pain has never been demonstrated. Taking advantage of the high spatiotemporal resolution of direct intracerebral recordings, we investigated whether the human insula exhibits local field potentials (LFPs) specific for pain. Forty-seven insular sites were investigated. Participants received brief stimuli belonging to four different modalities (nociceptive, vibrotactile, auditory, and visual). Both nociceptive stimuli and non-nociceptive vibrotactile, auditory, and visual stimuli elicited consistent LFPs in the posterior and anterior insula, with matching spatial distributions. Furthermore, a blind source separation procedure showed that nociceptive LFPs are largely explained by multimodal neural activity also contributing to non-nociceptive LFPs. By revealing that LFPs elicited by nociceptive stimuli reflect activity unrelated to nociception and pain, our results confute the widespread assumption that these brain responses are a signature for pain perception and its modulation. PMID:26734726

  8. Class-specific weighting for Markov random field estimation: application to medical image segmentation.

    PubMed

    Monaco, James P; Madabhushi, Anant

    2012-12-01

    Many estimation tasks require Bayesian classifiers capable of adjusting their performance (e.g. sensitivity/specificity). In situations where the optimal classification decision can be identified by an exhaustive search over all possible classes, means for adjusting classifier performance, such as probability thresholding or weighting the a posteriori probabilities, are well established. Unfortunately, analogous methods compatible with Markov random fields (i.e. large collections of dependent random variables) are noticeably absent from the literature. Consequently, most Markov random field (MRF) based classification systems typically restrict their performance to a single, static operating point (i.e. a paired sensitivity/specificity). To address this deficiency, we previously introduced an extension of maximum posterior marginals (MPM) estimation that allows certain classes to be weighted more heavily than others, thus providing a means for varying classifier performance. However, this extension is not appropriate for the more popular maximum a posteriori (MAP) estimation. Thus, a strategy for varying the performance of MAP estimators is still needed. Such a strategy is essential for several reasons: (1) the MAP cost function may be more appropriate in certain classification tasks than the MPM cost function, (2) the literature provides a surfeit of MAP estimation implementations, several of which are considerably faster than the typical Markov Chain Monte Carlo methods used for MPM, and (3) MAP estimation is used far more often than MPM. Consequently, in this paper we introduce multiplicative weighted MAP (MWMAP) estimation-achieved via the incorporation of multiplicative weights into the MAP cost function-which allows certain classes to be preferred over others. This creates a natural bias for specific classes, and consequently a means for adjusting classifier performance. Similarly, we show how this multiplicative weighting strategy can be applied to the MPM

  9. Context-specific influence of water temperature on brook trout growth rates in the field

    USGS Publications Warehouse

    Xu, C.; Letcher, B.H.; Nislow, K.H.

    2010-01-01

    1. Modelling the effects of climate change on freshwater fishes requires robust field-based estimates accounting for interactions among multiple factors.2. We used data from an 8-year individual-based study of a wild brook trout (Salvelinus fontinalis) population to test the influence of water temperature on season-specific growth in the context of variation in other environmental (i.e. season, stream flow) or biotic factors (local brook trout biomass density and fish age and size) in West Brook, a third-order stream in western Massachusetts, U.S.A.3. Changes in ambient temperature influenced individual growth rates. In general, higher temperatures were associated with higher growth rates in winter and spring and lower growth rates in summer and autumn. However, the effect of temperature on growth was strongly context-dependent, differing in both magnitude and direction as a function of season, stream flow and fish biomass density.4. We found that stream flow and temperature had strong and complex interactive effects on trout growth. At the coldest temperatures (in winter), high stream flows were associated with reduced trout growth rates. During spring and autumn and in typical summers (when water temperatures were close to growth optima), higher flows were associated with increased growth rates. In addition, the effect of flow at a given temperature (the flow-temperature interaction) differed among seasons.5. Trout density negatively affected growth rate and had strong interactions with temperature in two of four seasons (i.e. spring and summer) with greater negative effects at high temperatures.6. Our study provided robust, integrative field-based estimates of the effects of temperature on growth rates for a species which serves as a model organism for cold-water adapted ectotherms facing the consequences of environmental change. Results of the study strongly suggest that failure to derive season-specific estimates, or to explicitly consider interactions with

  10. Development and applications of energy-specific fluence monitor for field monitoring.

    PubMed

    Krishnakumar, D N; Somayaji, K M; Venkatesan, R; Meenakshisundaram, V

    2011-07-01

    A portable energy-specific fluence monitor is developed for field monitoring as well as to serve as stand-alone data acquisition system to measure dose rate due to routine releases at various locations in and around Nuclear Power Reactors. The data from an array of such monitors deployed over a region of interest would help in evolving a methodology to arrive at the source term evaluation in the event of a postulated nuclear incident. The other method that exists for this purpose is by conducting tracer experiments using known release of a gas like SF(6) into the atmosphere and monitoring their concentrations downwind. The above instrument enables one to use the routine release of (41)Ar as a tracer gas. The Argon fluence monitor houses a CsI(Tl) detector and associated miniature electronics modules for conditioning the signal from the detector. Data logging and in-situ archival of the data are controlled by a powerful web enabled communication controller preloaded with Microsoft Windows Compact Edition (WIN CE). The application software is developed in Visual Basic.NET under Compact Framework and deployed in the module. The paper gives an outline of the design aspects of the instrument, associated electronics and calibration of the instrument, including the preliminary results obtained using the instrument. The utility of the system is established by carrying out field survey around Madras Atomic Power Station (MAPS), consisting of two Pressurized Heavy Water Reactors (PHWR), by mapping the (41)Ar plume. Additional features such as enhancing the monitor capability with embedded GPS along with real-time linking using wireless networking techniques are also being incorporated. PMID:21367610

  11. A SUGGESTED CURRICULUM GUIDE FOR ELECTRO-MECHANICAL TECHNOLOGY ORIENTED SPECIFICALLY TO THE COMPUTER AND BUSINESS MACHINE FIELDS. INTERIM REPORT.

    ERIC Educational Resources Information Center

    LESCARBEAU, ROLAND F.; AND OTHERS

    A SUGGESTED POST-SECONDARY CURRICULUM GUIDE FOR ELECTRO-MECHANICAL TECHNOLOGY ORIENTED SPECIFICALLY TO THE COMPUTER AND BUSINESS MACHINE FIELDS WAS DEVELOPED BY A GROUP OF COOPERATING INSTITUTIONS, NOW INCORPORATED AS TECHNICAL EDUCATION CONSORTIUM, INCORPORATED. SPECIFIC NEEDS OF THE COMPUTER AND BUSINESS MACHINE INDUSTRY WERE DETERMINED FROM…

  12. Magnetic field dependence of the specific heat of some high-T/sub c/

    SciTech Connect

    Phillips, N.E.; Fisher, R.A.; Lacy, S.E.; Marcenat, C.; Olsen, J.A.; Ham, W.K.; Stacy, A.M.

    1987-04-01

    The specific heats, C, of 5 samples of La/sub 1.85/M/sub 0.15/CuO/sub 4-y/ (M = Ca, Sr, Ba), one sample of La/sub 2/CuO/sub 4-y/, and one sample of YBa/sub 2/Cu/sub 3/O/sub 9-y/ have been measured between 0.4 and 40K, in magnetic fields, H, to 7T. For the La/sub 1.85/M/sub 0.15/CuO/sub 4-y/ samples the H dependence of C near T/sub c/ and near 1K, where C is dominated by the electronic contribution, gives information about the fraction of the sample that is a bulk superconductor and the density of electronic states. The fraction of bulk superconductivity indicated by the Meissner effect does not correlate well with that indicated by C. La/sub 2/CuO/sub 4-y/ has a linear term in C, in qualitative agreement with a theoretical prediction.

  13. The Application Of Microbial Enhanced Oil Recovery On Unconventional Oil: A Field Specific Approach

    NASA Astrophysics Data System (ADS)

    Goodman, Sean; Millar, Andrew; Allison, Heather; McCarthy, Alan

    2014-05-01

    A substantial amount of the world's recoverable oil reserves are made from unconventional or heavy resources. However, great difficulty has been had in recovering this oil after primary and secondary recovery methods have been employed. Therefore, tertiary methods such as microbial enhanced oil recovery (MEOR) have been employed. MEOR involves the use of bacteria and their metabolic products to alter the oil properties or rock permeability within a reservoir in order to promote the flow of oil. Although MEOR has been trialed in the past with mixed outcomes, its feasibility on heavier oils has not been demonstrated. The aim of this study is to show that MEOR can be successfully applied to unconventional oils. By using an indigenous strain of bacteria isolated from a reservoir of interest and applied to field specific microcosms, we will look into the effect of these bacteria compared to variant inoculums to identify which mechanisms of action the bacteria are using to improve recovery. Using this information, we will be able to identify genes of interest and groups of bacteria that may be beneficial for MEOR and look accurately identify favorable bacteria within a reservoir.

  14. Compound-Specific Carbon and Hydrogen Isotope Analysis - Field Evidence of MTBE Bioremediation

    NASA Astrophysics Data System (ADS)

    Kuder, T.; Kolhatkar, R. V.; Philp, P.; Wilson, J. T.; Landmeyer, J. E.; Allen, J.

    2002-12-01

    Compound-specific stable isotope analysis allows opportunity to determine the isotopic ratios of individual contaminants. The technique has been applied to confirm biodegradation in studies of chlorinated solvents and recently BTEX, MTBE and TBA. Chemical reactions (including bio- and inorganic degradation) tend to favor molecules with the lighter isotopic species (e.g., 12C, 1H), resulting with enrichment of the unreacted substrate in the heavier isotopic species (13C, D), referred to as kinetic isotopic fractionation, so that the extent of fractionation may be used as a proxy for biodegradation. Processes such as volatilization, sorption etc., result in minimal degree of fractionation and do not interfere with the isotopic signal due to biodegradation. The results presented here show the first successful applications of compound-specific isotope analysis to understanding MTBE biodegradation in the field, at both aerobic and anaerobic sites. Observed fractionations suggest that two different biodegradation pathways may be involved. At a number of anaerobic locations major fractionation effects were observed for both C and H; enrichment factors Ÿnfor both elements were approaching or exceeding -10. A laboratory microcosm study using an enrichment culture yielded similar results (C data only). A characteristic feature of these sites was the presence of high concentrations of TBA. Conversely, at a number of sites, the C composition remained stable with little fractionation and stayed within the analytical precision range or changed minimally, while H displayed significant fractionation in excess of 60 per mil. Moderate agreement of the data with Rayleigh fractionation model was observed, suggesting that biodegradation effect was distorted by variability at the source or the plume was not homogeneous. The enrichment factor calculated for these data is similar to the one Ÿnpublished for aerobic microcosm of MTBE-degrading culture from Vandenberg AFB by Gray et al

  15. Geochemical Specific Characters of the Oil and the Origin of the Oil and Gas Fields

    NASA Astrophysics Data System (ADS)

    Gottikh, Rimma; Pisotskiy, Bogdan; Plotnikova, Irina

    2010-05-01

    and porous rocks. The high metal content of carbonaceous substances and their compositional variations governed by homogenisation temperatures of the inclusions suggest that they are not the products of the decomposition of oil fields. The constant presence of uranium in the fluid and its differentiation products allows the tracing of the systems' migration ways from the crystalline basement to oil-saturated reservoir zones of the sedimentary cover The known geochemical properties of bitumen and oil - high platinum content, specific distributions of rare earth elements, that are not characteristic of the upper crust formations, as well as 143Nd/144Nd and 87Sr/86Sr isotopic compounds, which are out of balance with the organic matter of sedimentary rocks - suggest that hydrocarbons are accumulated in the presence of cooling high-alkalinity mafite-ultramafite intrusions. This logically corresponds to the distribution of seismic anomalies and magnetic and gravity fields in the consolidated crust below the various petroleum fields (for example, South Tatarstan and Nepsky arches of the Romashkino and Verkhne-Chonskoye oil fields). The acquired geochemical and thermodynamic characteristics of the reduced fluids and their differentiation products from the crystalline basement and the sedimentary cover of the southern Siberian and eastern East European platforms indicate that these were formed outside of the sedimentary cover and that the migration was directed upwards. The analysis of the magmatic evolution on platforms reveals its alkaline trend due to the impeded degassing of magmatic sources at depth and the inflow of new doses of alkaline fluids or melts into them. Further evolution of the zones of partial melting of the substratum led, in the authors' view, to the generation of oil-forming fluids and their transportation into the Earth's upper crust. Their interaction with the surrounding rocks in turn led to the formation of oil accumulations. Thus, oil is the product

  16. Specific Heat in High Magnetic Fields of BaFe2(As1-xPx)2

    NASA Astrophysics Data System (ADS)

    Moir, Camilla M.; Galvis, Jose A.; Walmsley, Phillip; Analytis, James G.; Chu, Jiun-Haw; Fisher, Ian R.; Shekhter, Arkady; Boebinger, Greg S.; Riggs, Scott C.

    We measure the magnetic field dependence of the specific heat in BaFe2(As1-xPx)2 with x ranging from x =0.31 to x =0.6 in fields up to 34.5T. We report three important observations: √H behavior indicating a nodal superconducting gap with a linear energy dispersion, saturation of the heat capacity at the magnetic field that corresponds to the resistive onset, and a calculated quasiparticle mass using the increase in the electronic specific heat coefficient when entering the normal state, Δγ = γ (34.5T) - γ(0T), as a measure of the normal state specific heat.

  17. Species-specific photosynthetic responses of four coniferous seedlings to open-field experimental warming

    NASA Astrophysics Data System (ADS)

    Han, S.; Yoon, S. J.; Yoon, T. K.; Han, S. H.; Lee, J.; Lee, D.; Kim, S.; Hwang, J.; Cho, M.; Son, Y.

    2014-12-01

    Temperature increase under climate change is expected to affect photosynthesis of tree species. Biochemical models generally suggest that the elevated temperature increases the photosynthetic carbon fixation, however, many opposing results were reported as well. We aimed to examine the photosynthetic responses of four coniferous seedlings to projected future temperature increase, by conducting an open-field warming experiment. Experimental warming set-up using infra-red heater was built in 2011 and the temperature in warming plots has been regulated to be consistently 3oC higher than that of control plots. The seeds of Abies holophylla (AH), A. koreana (AK), Pinus densiflora (PD), and P. koraiensis (PK) were planted in each 1 m × 1 m plot (n=3) in April, 2012. Monthly net photosynthetic rates (Pn; μmol CO2 m-2 s-1) of 1-year-old seedlings (n=9) from June to November, 2013 were measured using CIRAS-2 (PP-Systems, UK) and photosynthetic parameters (the apparent quantum yield; ф; µmol CO2 mol-1, the dark respiration rate; Rd; µmol CO2 mol-1, and the light compensation point; LCP; µmol mol-1 s-1) were also calculated from the light-response curve of photosynthesis in August, 2013. Chlorophyll contents were measured using DMSO extraction method. Monthly Pn was generally higher for PD and decreased for AK in warmed plots than in control plots (Fig. 1). Pn of AK and PK did not show any significant difference, however, Pn of PK in October and November increased by experimental warming. Pn of PD also showed the highest increase in November and this distinct increase of Pn in autumn might be caused by delayed cessation of photosynthesis by temperature elevation. ф and Rd in warmed plots were higher for PD and lower for AK, while LCP did not significantly differ by treatments for all species. Because ф is considered to be related to the efficiency of harvesting and using light, the change in ф might have caused the response of Pn to warming in this study. Decreases

  18. Field experiments to evaluate host plant specificity of prospective agents of Onopordum acanthium in Bulgaria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Scotch thistle, Onopordum acanthium, is an invasive alien weed in North America that originates from Europe. Previous field observations in Bulgaria have confirmed the presence of prospective biological control agents including Cassida rubiginosa, Chaetostomella cylindrica, Eublemma amoena, Larinus ...

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

    ERIC Educational Resources Information Center

    Kelly, Martin G.; Terrana, Sebastian

    2004-01-01

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

  20. Specific heat of the Skyrmion lattice phase and field-induced tricritical point in MnSi.

    PubMed

    Bauer, A; Garst, M; Pfleiderer, C

    2013-04-26

    We report high-precision measurements of the temperature and magnetic field dependence of the specific heat, C(T,H), across the magnetic phase diagram of MnSi. Clear anomalies establish the Skyrmion lattice unambiguously as a thermodynamic phase. The evolution of the specific heat anomalies, the field dependence of the entropy released at the phase transitions, and the temperature versus field dependence of crossover lines provide striking evidence of a tricritical point at μ0H(TCP)(int) = 340  mT and T(TCP) = 28.5  K. The existence of this tricritical point represents strong support of a helimagnetic Brazovskii transition, i.e., a fluctuation-induced first-order transition at H = 0. PMID:23679769

  1. Knowledge About Sounds-Context-Specific Meaning Differently Activates Cortical Hemispheres, Auditory Cortical Fields, and Layers in House Mice.

    PubMed

    Geissler, Diana B; Schmidt, H Sabine; Ehret, Günter

    2016-01-01

    Activation of the auditory cortex (AC) by a given sound pattern is plastic, depending, in largely unknown ways, on the physiological state and the behavioral context of the receiving animal and on the receiver's experience with the sounds. Such plasticity can be inferred when house mouse mothers respond maternally to pup ultrasounds right after parturition and naïve females have to learn to respond. Here we use c-FOS immunocytochemistry to quantify highly activated neurons in the AC fields and layers of seven groups of mothers and naïve females who have different knowledge about and are differently motivated to respond to acoustic models of pup ultrasounds of different behavioral significance. Profiles of FOS-positive cells in the AC primary fields (AI, AAF), the ultrasonic field (UF), the secondary field (AII), and the dorsoposterior field (DP) suggest that activation reflects in AI, AAF, and UF the integration of sound properties with animal state-dependent factors, in the higher-order field AII the news value of a given sound in the behavioral context, and in the higher-order field DP the level of maternal motivation and, by left-hemisphere activation advantage, the recognition of the meaning of sounds in the given context. Anesthesia reduced activation in all fields, especially in cortical layers 2/3. Thus, plasticity in the AC is field-specific preparing different output of AC fields in the process of perception, recognition and responding to communication sounds. Further, the activation profiles of the auditory cortical fields suggest the differentiation between brains hormonally primed to know (mothers) and brains which acquired knowledge via implicit learning (naïve females). In this way, auditory cortical activation discriminates between instinctive (mothers) and learned (naïve females) cognition. PMID:27013959

  2. Knowledge About Sounds—Context-Specific Meaning Differently Activates Cortical Hemispheres, Auditory Cortical Fields, and Layers in House Mice

    PubMed Central

    Geissler, Diana B.; Schmidt, H. Sabine; Ehret, Günter

    2016-01-01

    Activation of the auditory cortex (AC) by a given sound pattern is plastic, depending, in largely unknown ways, on the physiological state and the behavioral context of the receiving animal and on the receiver's experience with the sounds. Such plasticity can be inferred when house mouse mothers respond maternally to pup ultrasounds right after parturition and naïve females have to learn to respond. Here we use c-FOS immunocytochemistry to quantify highly activated neurons in the AC fields and layers of seven groups of mothers and naïve females who have different knowledge about and are differently motivated to respond to acoustic models of pup ultrasounds of different behavioral significance. Profiles of FOS-positive cells in the AC primary fields (AI, AAF), the ultrasonic field (UF), the secondary field (AII), and the dorsoposterior field (DP) suggest that activation reflects in AI, AAF, and UF the integration of sound properties with animal state-dependent factors, in the higher-order field AII the news value of a given sound in the behavioral context, and in the higher-order field DP the level of maternal motivation and, by left-hemisphere activation advantage, the recognition of the meaning of sounds in the given context. Anesthesia reduced activation in all fields, especially in cortical layers 2/3. Thus, plasticity in the AC is field-specific preparing different output of AC fields in the process of perception, recognition and responding to communication sounds. Further, the activation profiles of the auditory cortical fields suggest the differentiation between brains hormonally primed to know (mothers) and brains which acquired knowledge via implicit learning (naïve females). In this way, auditory cortical activation discriminates between instinctive (mothers) and learned (naïve females) cognition. PMID:27013959

  3. SU-C-304-07: Are Small Field Detector Correction Factors Strongly Dependent On Machine-Specific Characteristics?

    SciTech Connect

    Mathew, D; Tanny, S; Parsai, E; Sperling, N

    2015-06-15

    Purpose: The current small field dosimetry formalism utilizes quality correction factors to compensate for the difference in detector response relative to dose deposited in water. The correction factors are defined on a machine-specific basis for each beam quality and detector combination. Some research has suggested that the correction factors may only be weakly dependent on machine-to-machine variations, allowing for determinations of class-specific correction factors for various accelerator models. This research examines the differences in small field correction factors for three detectors across two Varian Truebeam accelerators to determine the correction factor dependence on machine-specific characteristics. Methods: Output factors were measured on two Varian Truebeam accelerators for equivalently tuned 6 MV and 6 FFF beams. Measurements were obtained using a commercial plastic scintillation detector (PSD), two ion chambers, and a diode detector. Measurements were made at a depth of 10 cm with an SSD of 100 cm for jaw-defined field sizes ranging from 3×3 cm{sup 2} to 0.6×0.6 cm{sup 2}, normalized to values at 5×5cm{sup 2}. Correction factors for each field on each machine were calculated as the ratio of the detector response to the PSD response. Percent change of correction factors for the chambers are presented relative to the primary machine. Results: The Exradin A26 demonstrates a difference of 9% for 6×6mm{sup 2} fields in both the 6FFF and 6MV beams. The A16 chamber demonstrates a 5%, and 3% difference in 6FFF and 6MV fields at the same field size respectively. The Edge diode exhibits less than 1.5% difference across both evaluated energies. Field sizes larger than 1.4×1.4cm2 demonstrated less than 1% difference for all detectors. Conclusion: Preliminary results suggest that class-specific correction may not be appropriate for micro-ionization chamber. For diode systems, the correction factor was substantially similar and may be useful for class-specific

  4. Generality with Specificity: The Dynamic Field Theory Generalizes across Tasks and Time Scales

    ERIC Educational Resources Information Center

    Simmering, Vanessa R.; Spencer, John P.

    2008-01-01

    A central goal in cognitive and developmental science is to develop models of behavior that can generalize across both tasks and development while maintaining a commitment to detailed behavioral prediction. This paper presents tests of one such model, the Dynamic Field Theory (DFT). The DFT was originally proposed to capture delay-dependent biases…

  5. Variable rate application of nematicides on cotton fields: A promising site-specific management strategy.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field tests were conducted to determine if differences in response to nematicide application (i.e., root-knot nematode (RKN) population levels, cotton yield, and profitability) occurred among RKN management zones (MZ). The MZ were delineated using variables related to soil texture, including appare...

  6. Analyzing Student Performance in Specific Subject Area Indicators on the ETS Major Field Test in Business

    ERIC Educational Resources Information Center

    Settlage, Daniel Murray; Wollscheid, Jim R.

    2015-01-01

    The Major Field Test is a commonly used assessment instrument, but little emphasis has been put on analyzing student-level subject area indicator scores. The Educational Testing Service recently made these data available to institutions, and it is analyzed here. This analysis builds on previous work by incorporating demographic and programmatic…

  7. Magneto-electric Nanoparticles to Enable Field-controlled High-Specificity Drug Delivery to Eradicate Ovarian Cancer Cells

    NASA Astrophysics Data System (ADS)

    Guduru, Rakesh; Liang, Ping; Runowicz, Carolyn; Nair, Madhavan; Atluri, Venkata; Khizroev, Sakhrat

    2013-10-01

    The nanotechnology capable of high-specificity targeted delivery of anti-neoplastic drugs would be a significant breakthrough in Cancer in general and Ovarian Cancer in particular. We addressed this challenge through a new physical concept that exploited (i) the difference in the membrane electric properties between the tumor and healthy cells and (ii) the capability of magneto-electric nanoparticles (MENs) to serve as nanosized converters of remote magnetic field energy into the MENs' intrinsic electric field energy. This capability allows to remotely control the membrane electric fields and consequently trigger high-specificity drug uptake through creation of localized nano-electroporation sites. In in-vitro studies on human ovarian carcinoma cell (SKOV-3) and healthy cell (HOMEC) lines, we applied a 30-Oe d.c. field to trigger high-specificity uptake of paclitaxel loaded on 30-nm CoFe2O4@BaTiO3 MENs. The drug penetrated through the membrane and completely eradicated the tumor within 24 hours without affecting the normal cells.

  8. Magneto-electric Nanoparticles to Enable Field-controlled High-Specificity Drug Delivery to Eradicate Ovarian Cancer Cells

    PubMed Central

    Guduru, Rakesh; Liang, Ping; Runowicz, Carolyn; Nair, Madhavan; Atluri, Venkata; Khizroev, Sakhrat

    2013-01-01

    The nanotechnology capable of high-specificity targeted delivery of anti-neoplastic drugs would be a significant breakthrough in Cancer in general and Ovarian Cancer in particular. We addressed this challenge through a new physical concept that exploited (i) the difference in the membrane electric properties between the tumor and healthy cells and (ii) the capability of magneto-electric nanoparticles (MENs) to serve as nanosized converters of remote magnetic field energy into the MENs' intrinsic electric field energy. This capability allows to remotely control the membrane electric fields and consequently trigger high-specificity drug uptake through creation of localized nano-electroporation sites. In in-vitro studies on human ovarian carcinoma cell (SKOV-3) and healthy cell (HOMEC) lines, we applied a 30-Oe d.c. field to trigger high-specificity uptake of paclitaxel loaded on 30-nm CoFe2O4@BaTiO3 MENs. The drug penetrated through the membrane and completely eradicated the tumor within 24 hours without affecting the normal cells. PMID:24129652

  9. Site-specific risk factors for ray blight in Tasmanian pyrethrum fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ray blight of pyrethrum, caused by Phoma ligulicola var. inoxydablis can cause significant reductions in crop growth and pyrethrin yield. Weather and site-specific disease risk factors for ray blight have not been identified or quantified in terms of relative risk, which has limited the efficiency ...

  10. Position-specific adaptation in complex cell receptive fields of the cat striate cortex.

    PubMed

    Marlin, S; Douglas, R; Cynader, M

    1993-06-01

    1. Responses of complex cells in cat striate cortex were studied with flashed light slit stimuli. The responses to slits flashed in different positions in the receptive field were assessed quantitatively before and after periods of prolonged stimulation of one small region of the receptive field. This type of prolonged stimulation resulted in reduced responsivity over a limited zone within the complex cell receptive field. 2. The adaptation-induced responsivity decrement was generally observed in both the ON and OFF response profiles but could also be restricted to one or the other. In general, the magnitude of the response decrements was greatest in the ON response profiles. The adaptation-induced response decrement did not necessarily spread throughout the receptive field but was restricted to a small region surrounding the adapted receptive field position (RFP). Adaptation spread equally widely across the ON and OFF response profiles despite the smaller adaptation effects in the OFF profile. 3. The adaptation effects from repeated stimulation at a single RFP did not spread symmetrically across the receptive field, and a given cell's preferred direction of motion indicated the direction of the asymmetric spread of the adaptation. RFPs that would be stimulated by a light slit originating at the point of adaptation and moving in the preferred direction (preferred side) showed greater adaptation-induced response decrements than did RFPs that would be stimulated by a light slit moving in the opposite direction from the point of adaptation (nonpreferred side). There was significant enhancement of responses at some RFPs on the non-preferred side of the point of adaptation. This asymmetric spread of adaptation could be caused by adaptation of inhibitory connections that contribute to complex cell direction selectivity. 4. The asymmetry of adaptation was significantly different for the ON and OFF response profiles. The asymmetric spread of adaptation for the ON response

  11. Survey on Different Samsung with Nokia Smart Mobile Phones in the Specific Absorption Rate Electrical Field of Head.

    PubMed

    Fakhri, Yadolah; Alinejad, Azim; Keramati, Hassan; Bay, Abotaleb; Avazpour, Moayed; Zandsalimi, Yahya; Moradi, Bigard; Rasouli Amirhajeloo, Leila; Mirzaei, Maryam

    2016-01-01

    The use of smart phones is increasing in the world. This excessive use, especially in the last two decades, has created too much concern on the effects of emitted electromagnetic fields and specific absorption rate on human health. In this descriptive-analytical study of the electric field resulting from smart phones of Samsung and Nokia by portable measuring device, electromagnetic field, Model HI-3603-VDT/VLF, were measured. Then, head absorption rate was calculated in these two mobiles by ICNIRP equation. Finally, the comparison of specific absorption rate, especially between Samsung and Nokia smart phones, was conducted by T-Test statistics analysis. The mean of electric field for Samsung and Nokia smart mobile phones was obtained 1.8 ±0.19 v/m  and 2.23±0.39 v/m , respectively, while the range of the electric field was obtained as 1.56-2.21 v/m and 1.69-2.89 v/m for them, respectively. The mean of specific absorption rate in Samsung and Nokia was obtained 0.002 ± 0.0005 W/Kg and 0.0041±0.0013 W/Kg at the frequency of 900 MHz and 0.004±0.001 W/Kg and 0.0062±0.0002 W/Kg at the frequency of 1800 MHz respectively. The ratio of mean electronic field to guidance in the Samsung mobile phone at the frequency of 900 MHz and 1800 MHz was 4.36% and 3.34%, while was 5.62% and 4.31% in the Nokia mobile phone, respectively. The ratio of mean head specific absorption rate in smart mobile phones of Samsung and Nokia in the guidance level at the frequency of 900 was 0.15% and 0.25%, respectively, while was 0.23 %and 0.38% at the frequency of 1800 MHz, respectively. The rate of specific absorption of Nokia smart  mobile phones at the frequencies of 900 and 1800 MHz  was significantly higher than Samsung (p value <0.05). Hence, we can say that in a fixed period, health risks of Nokia smart phones is higher than Samsung smart mobile phone. PMID:27157169

  12. Magnetic field dependence of low-temperature specific heat of the spinel oxide superconductor LiTi2 O4

    NASA Astrophysics Data System (ADS)

    Sun, C. P.; Lin, J.-Y.; Mollah, S.; Ho, P. L.; Yang, H. D.; Hsu, F. C.; Liao, Y. C.; Wu, M. K.

    2004-08-01

    Magnetic field dependence of low temperature specific heat of spinel oxide superconductor LiTi2O4 has been elaborately investigated. In the normal state, the obtained electronic coefficient of specific heat γn=19.15mJ/molK2 , the Debye temperature ΘD=657K and some other parameters are compared with those reported earlier. The superconducting transition at Tc˜11.4K is very sharp (ΔTc˜0.3K) and the estimated δC/γnTc is ˜1.78 . In the superconducting state, the best fit of data leads to the electronic specific heat Ces/γnTc=9.87exp(-1.58Tc/T) without field and γ(H)∝H0.95 with fields. In addition, Hc2(0)˜11.7T , Hc(0)˜0.32T , ξGL(0)˜55Å , λGL(0)˜1600Å , and Hc1(0)˜26mT are estimated from the Werthamer-Helfand-Hohenberg (WHH) theory or other relevant relations. All results from the present study indicate that LiTi2O4 can be well described by a typical type-II, BCS-like, moderate coupling, and fully gapped superconductor in the dirty limit. It is further suggested that LiTi2O4 is a moderately electron-electron correlated system.

  13. MHD-Based Specification of Magnetotail Plasma and Fields: Possibilities and Limitations

    NASA Technical Reports Server (NTRS)

    Hesse, M.; Birn, J.

    2000-01-01

    Magnetohydrodynamics (MHD) constitutes the simplest comprehensive and self-consistent formulation of the properties of space plasmas. As such, it has been applied with large success to the dynamics of solar system plasmas. For the nightside region of the Earth, the magnetotail, MHD simulations have led to new understanding of the structure and dynamics of the plasmas, in response to both changes in boundary conditions as well as internal dynamical processes. As a result, substantial knowledge of the structure and dynamics of the nightside region have been accumulated. In basic MHD conservation laws on magnetospheric structure, as well as the role of non-MHD processes in the initiation and evolution of dynamical processes of the magnetotail. This presentation will consist of three parts, the first of which addresses the basic constraints on magnetotail structure as well as their consequences for magnetotail specification and forecasting. We will then review some examples of magnetotail structural changes brought about by solar-wind-like boundary conditions. Last, we consider the role of non-MHD processes in magnetotail specification and forecasting. The emphasis here will be on inclusion of these processes into MHD models, and their impact on the overall structure and dynamics.

  14. Monte Carlo study of internal energy and specific heat of a nano-graphene bilayer in a longitudinal magnetic field

    NASA Astrophysics Data System (ADS)

    Luo, Xiao-hong; Wang, Wei; Chen, Dong-dong; Xu, Si-yuan

    2016-06-01

    The thermodynamic properties of a nano-graphene bilayer, consisting of the upper layer A of spin-3/2 with antiferromagnetic intralayer exchange coupling and the bottom layer B of spin-5/2 with ferromagnetic intralayer exchange coupling, have been studied by the use of Monte Carlo simulation. We find a number of characteristic phenomena. The effects of the exchange coupling, the single-ion anisotropy and the longitudinal magnetic field on the internal energy, the specific heat and the blocking temperature of the mixed-spin bilayer system have been investigated in detail. The internal energy and the specific heat profiles are clarified. In particular, we have found that the specific heat curve may show two peaks phenomenon for appropriate values of the system parameters.

  15. Residue-specific force field based on the protein coil library. RSFF1: modification of OPLS-AA/L.

    PubMed

    Jiang, Fan; Zhou, Chen-Yang; Wu, Yun-Dong

    2014-06-26

    Traditional protein force fields use one set of parameters for most of the 20 amino acids (AAs), allowing transferability of the parameters. However, a significant shortcoming is the difficulty to fit the Ramachandran plots of all AA residues simultaneously, affecting the accuracy of the force field. In this Feature Article, we report a new strategy for protein force field parametrization. Backbone and side-chain conformational distributions of all 20 AA residues obtained from protein coil library were used as the target data. The dihedral angle (torsion) potentials and some local nonbonded (1-4/1-5/1-6) interactions in OPLS-AA/L force field were modified such that the target data can be excellently reproduced by molecular dynamics simulations of dipeptides (blocked AAs) in explicit water, resulting in a new force field with AA-specific parameters, RSFF1. An efficient free energy decomposition approach was developed to separate the corrections on ϕ and ψ from the two-dimensional Ramachandran plots. RSFF1 is shown to reproduce the experimental NMR (3)J-coupling constants of AA dipeptides better than other force fields. It has a good balance between α-helical and β-sheet secondary structures. It can successfully fold a set of α-helix proteins (Trp-cage and Homeodomain) and β-hairpins (Trpzip-2, GB1 hairpin), which cannot be consistently stabilized by other state-of-the-art force fields. Interestingly, the RSFF1 force field systematically overestimates the melting temperature (and the stability of native state) of these peptides/proteins. It has a potential application in the simulation of protein folding and protein structure refinement. PMID:24815738

  16. Radiofrequency electromagnetic field exposure and non-specific symptoms of ill health: A systematic review

    SciTech Connect

    Roeoesli, Martin

    2008-06-15

    This article is a systematic review of whether everyday exposure to radiofrequency electromagnetic field (RF-EMF) causes symptoms, and whether some individuals are able to detect low-level RF-EMF (below the ICNIRP [International Commission on Non-Ionizing Radiation Protection] guidelines). Peer-reviewed articles published before August 2007 were identified by means of a systematic literature search. Meta-analytic techniques were used to pool the results from studies investigating the ability to discriminate active from sham RF-EMF exposure. RF-EMF discrimination was investigated in seven studies including a total of 182 self-declared electromagnetic hypersensitive (EHS) individuals and 332 non-EHS individuals. The pooled correct field detection rate was 4.2% better than expected by chance (95% CI: -2.1 to 10.5). There was no evidence that EHS individuals could detect presence or absence of RF-EMF better than other persons. There was little evidence that short-term exposure to a mobile phone or base station causes symptoms based on the results of eight randomized trials investigating 194 EHS and 346 non-EHS individuals in a laboratory. Some of the trials provided evidence for the occurrence of nocebo effects. In population based studies an association between symptoms and exposure to RF-EMF in the everyday environment was repeatedly observed. This review showed that the large majority of individuals who claims to be able to detect low level RF-EMF are not able to do so under double-blind conditions. If such individuals exist, they represent a small minority and have not been identified yet. The available observational studies do not allow differentiating between biophysical from EMF and nocebo effects.

  17. Site-Specific Spectroscopic Reporters of the Local Electric Field, Hydration, Structure, and Dynamics of Biomolecules

    PubMed Central

    Waegele, Matthias M.; Culik, Robert M.; Gai, Feng

    2011-01-01

    Elucidating the underlying molecular mechanisms of protein folding and function is a very exciting and active research area, but poses significant challenges. This is due in part to the fact that existing experimental techniques are incapable of capturing snapshots along the ‘reaction coordinate’ in question with both sufficient spatial and temporal resolutions. In this regard, recent years have seen increased interests and efforts in development and employment of site-specific probes to enhance the structural sensitivity of spectroscopic techniques in conformational and dynamical studies of biological molecules. In particular, the spectroscopic and chemical properties of nitriles, thiocyanates, and azides render these groups attractive for the interrogation of complex biochemical constructs and processes. Here, we review their signatures in vibrational, fluorescence and NMR spectra and their utility in the context of elucidating chemical structure and dynamics of protein and DNA molecules. PMID:22003429

  18. Are there specific translational challenges in regenerative medicine? Lessons from other fields.

    PubMed

    Gardner, John; Faulkner, Alex; Mahalatchimy, Aurélie; Webster, Andrew

    2015-01-01

    There is concern that translation 'from bench to bedside' within regenerative medicine (RM) will fail to materialize, or will be dismally slow, due to various challenges arising from the highly novel and disruptive nature of RM. In this article, we provide a summary of these challenges, and we critically engage with the notion that such challenges are specific to RM. It is important, we argue, not to overstate the exceptional nature of RM, as valuable lessons can be learned from elsewhere in medicine. Using several examples of technology adoption, we suggest that emerging RM products and procedures will have to work hard to find or create an adoption space if translation into the clinic is to be successful. PMID:26541074

  19. Terminal field specificity of forebrain efferent axons to the pontine parabrachial nucleus and medullary reticular formation

    PubMed Central

    Zhang, Chi; Kang, Yi; Lundy, Robert F.

    2010-01-01

    The pontine parabrachial nucleus (PBN) and medullary reticular formation (RF) are hindbrain regions that, respectively, process sensory input and coordinate motor output related to ingestive behavior. Neural processing in each hindbrain site is subject to modulation originating from several forebrain structures including the insular gustatory cortex (IC), bed nucleus of the stria terminalis (BNST), central nucleus of the amygdala (CeA), and lateral hypothalamus (LH). The present study combined electrophysiology and retrograde tracing techniques to determine the extent of overlap between neurons within the IC, BNST, CeA and LH that target both the PBN and RF. One fluorescent retrograde tracer, red (RFB) or green (GFB) latex microbeads, was injected into the gustatory PBN under electrophysiological guidance and a different retrograde tracer, GFB or fluorogold (FG), into the ipsilateral RF using the location of gustatory NST as a point of reference. Brain tissue containing each forebrain region was sectioned, scanned using a confocal microscope, and scored for the number of single and double labeled neurons. Neurons innervating the RF only, the PBN only, or both the medullary RF and PBN were observed, largely intermingled, in each forebrain region. The CeA contained the largest number of cells retrogradely labeled after tracer injection into either hindbrain region. For each forebrain area except the IC, the origin of descending input to the RF and PBN was almost entirely ipsilateral. Axons from a small percentage of hindbrain projecting forebrain neurons targeted both the PBN and RF. Target specific and non specific inputs from a variety of forebrain nuclei to the hindbrain likely reflect functional specialization in the control of ingestive behaviors. PMID:21040715

  20. Entirely Carbohydrate-Based Vaccines: An Emerging Field for Specific and Selective Immune Responses.

    PubMed

    Nishat, Sharmeen; Andreana, Peter R

    2016-01-01

    Carbohydrates are regarded as promising targets for vaccine development against infectious disease because cell surface glycans on many infectious agents are attributed to playing an important role in pathogenesis. In addition, oncogenic transformation of normal cells, in many cases, is associated with aberrant glycosylation of the cell surface glycan generating tumor associated carbohydrate antigens (TACAs). Technological advances in glycobiology have added a new dimension to immunotherapy when considering carbohydrates as key targets in developing safe and effective vaccines to combat cancer, bacterial infections, viral infections, etc. Many consider effective vaccines induce T-cell dependent immunity with satisfactory levels of immunological memory that preclude recurrence. Unfortunately, carbohydrates alone are poorly immunogenic as they do not bind strongly to the MHCII complex and thus fail to elicit T-cell immunity. To increase immunogenicity, carbohydrates have been conjugated to carrier proteins, which sometimes can impede carbohydrate specific immunity as peptide-based immune responses can negate antibodies directed at the targeted carbohydrate antigens. To overcome many challenges in using carbohydrate-based vaccine design and development approaches targeting cancer and other diseases, zwitterionic polysaccharides (ZPSs), isolated from the capsule of commensal anaerobic bacteria, will be discussed as promising carriers of carbohydrate antigens to achieve desired immunological responses. PMID:27213458

  1. Entirely Carbohydrate-Based Vaccines: An Emerging Field for Specific and Selective Immune Responses

    PubMed Central

    Nishat, Sharmeen; Andreana, Peter R.

    2016-01-01

    Carbohydrates are regarded as promising targets for vaccine development against infectious disease because cell surface glycans on many infectious agents are attributed to playing an important role in pathogenesis. In addition, oncogenic transformation of normal cells, in many cases, is associated with aberrant glycosylation of the cell surface glycan generating tumor associated carbohydrate antigens (TACAs). Technological advances in glycobiology have added a new dimension to immunotherapy when considering carbohydrates as key targets in developing safe and effective vaccines to combat cancer, bacterial infections, viral infections, etc. Many consider effective vaccines induce T-cell dependent immunity with satisfactory levels of immunological memory that preclude recurrence. Unfortunately, carbohydrates alone are poorly immunogenic as they do not bind strongly to the MHCII complex and thus fail to elicit T-cell immunity. To increase immunogenicity, carbohydrates have been conjugated to carrier proteins, which sometimes can impede carbohydrate specific immunity as peptide-based immune responses can negate antibodies directed at the targeted carbohydrate antigens. To overcome many challenges in using carbohydrate-based vaccine design and development approaches targeting cancer and other diseases, zwitterionic polysaccharides (ZPSs), isolated from the capsule of commensal anaerobic bacteria, will be discussed as promising carriers of carbohydrate antigens to achieve desired immunological responses. PMID:27213458

  2. Magnetic nanoparticles with high specific absorption rate of electromagnetic energy at low field strength for hyperthermia therapy

    NASA Astrophysics Data System (ADS)

    Shubitidze, Fridon; Kekalo, Katsiaryna; Stigliano, Robert; Baker, Ian

    2015-03-01

    Magnetic nanoparticles (MNPs), referred to as the Dartmouth MNPs, which exhibit high specific absorption rate at low applied field strength have been developed for hyperthermia therapy applications. The MNPs consist of small (2-5 nm) single crystals of gamma-Fe2O3 with saccharide chains implanted in their crystalline structure, forming 20-40 nm flower-like aggregates with a hydrodynamic diameter of 110-120 nm. The MNPs form stable (>12 months) colloidal solutions in water and exhibit no hysteresis under an applied quasistatic magnetic field, and produce a significant amount of heat at field strengths as low as 100 Oe at 99-164 kHz. The MNP heating mechanisms under an alternating magnetic field (AMF) are discussed and analyzed quantitatively based on (a) the calculated multi-scale MNP interactions obtained using a three dimensional numerical model called the method of auxiliary sources, (b) measured MNP frequency spectra, and (c) quantified MNP friction losses based on magneto-viscous theory. The frequency responses and hysteresis curves of the Dartmouth MNPs are measured and compared to the modeled data. The specific absorption rate of the particles is measured at various AMF strengths and frequencies, and compared to commercially available MNPs. The comparisons demonstrate the superior heating properties of the Dartmouth MNPs at low field strengths (<250 Oe). This may extend MNP hyperthermia therapy to deeper tumors that were previously non-viable targets, potentially enabling the treatment of some of the most difficult cancers, such as pancreatic and rectal cancers, without damaging normal tissue.

  3. Magnetic nanoparticles with high specific absorption rate of electromagnetic energy at low field strength for hyperthermia therapy

    PubMed Central

    Stigliano, Robert; Baker, Ian

    2015-01-01

    Magnetic nanoparticles (MNPs), referred to as the Dartmouth MNPs, which exhibit high specific absorption rate at low applied field strength have been developed for hyperthermia therapy applications. The MNPs consist of small (2–5 nm) single crystals of gamma-Fe2O3 with saccharide chains implanted in their crystalline structure, forming 20–40 nm flower-like aggregates with a hydrodynamic diameter of 110–120 nm. The MNPs form stable (>12 months) colloidal solutions in water and exhibit no hysteresis under an applied quasistatic magnetic field, and produce a significant amount of heat at field strengths as low as 100 Oe at 99–164 kHz. The MNP heating mechanisms under an alternating magnetic field (AMF) are discussed and analyzed quantitatively based on (a) the calculated multi-scale MNP interactions obtained using a three dimensional numerical model called the method of auxiliary sources, (b) measured MNP frequency spectra, and (c) quantified MNP friction losses based on magneto-viscous theory. The frequency responses and hysteresis curves of the Dartmouth MNPs are measured and compared to the modeled data. The specific absorption rate of the particles is measured at various AMF strengths and frequencies, and compared to commercially available MNPs. The comparisons demonstrate the superior heating properties of the Dartmouth MNPs at low field strengths (<250 Oe). This may extend MNP hyperthermia therapy to deeper tumors that were previously non-viable targets, potentially enabling the treatment of some of the most difficult cancers, such as pancreatic and rectal cancers, without damaging normal tissue. PMID:25825545

  4. Plasmodium-specific molecular assays produce uninterpretable results and non-Plasmodium spp. sequences in field-collected Anopheles vectors.

    PubMed

    Harrison, Genelle F; Foley, Desmond H; Rueda, Leopoldo M; Melanson, Vanessa R; Wilkerson, Richard C; Long, Lewis S; Richardson, Jason H; Klein, Terry A; Kim, Heung-Chul; Lee, Won-Ja

    2013-12-01

    The Malaria Research and Reference Reagent Resource-recommended PLF/UNR/VIR polymerase chain reaction (PCR) was used to detect Plasmodium vivax in Anopheles spp. mosquitoes collected in South Korea. Samples that were amplified were sequenced and compared with known Plasmodium spp. by using the PlasmoDB.org Basic Local Alignment Search Tool/n and the National Center for Biotechnology Information Basic Local Alignment Search Tool/n tools. Results show that the primers PLF/UNR/VIR used in this PCR can produce uninterpretable results and non-specific sequences in field-collected mosquitoes. Three additional PCRs (PLU/VIV, specific for 18S small subunit ribosomal DNA; Pvr47, specific for a nuclear repeat; and GDCW/PLAS, specific for the mitochondrial marker, cytB) were then used to find a more accurate and interpretable assay. Samples that were amplified were again sequenced. The PLU/VIV and Pvr47 assays showed cross-reactivity with non-Plasmodium spp. and an arthropod fungus (Zoophthora lanceolata). The GDCW/PLAS assay amplified only Plasmodium spp. but also amplified the non-human specific parasite P. berghei from an Anopheles belenrae mosquito. Detection of P. berghei in South Korea is a new finding. PMID:24189365

  5. From field barley to malt: detection and specification of microbial activity for quality aspects.

    PubMed

    Noots, I; Delcour, J A; Michiels, C W

    1999-01-01

    Barley grain carries a numerous, variable, and complex microbial population that mainly consists of bacteria, yeasts, and filamentous fungi and that can partly be detected and quantified using plating methods and microscopic and molecular techniques. The extent and the activity of this microflora are determined by the altering state of the grain and the environmental conditions in the malt production chain. Three ecological systems can be distinguished: the growing cereal in the field, the dry barley grain under storage, and the germinating barley kernel during actual malting. Microorganisms interact with the malting process both by their presence and by their metabolic activity. In this respect, interference with the oxygen uptake by the barley grain and secretion of enzymes, hormones, toxins, and acids that may affect the plant physiological processes have been studied. As a result of the interaction, microorganisms can cause important losses and influence malt quality as measured by brewhouse performance and beer quality. Of particular concern is the occurrence of mycotoxins that may affect the safety of malt. The development of the microflora during malt production can to a certain extent be controlled by the selection of appropriate process conditions. Physical and chemical treatments to inactivate the microbial population on the barley grain are suggested. Recent developments, however, aim to control the microbial activity during malt production by promoting the growth of desirable microbial cultures, selected either as biocontrol agents inhibiting mycotoxin-producing molds or as starter cultures actively contributing to malt modification. Such techniques may offer natural opportunities to improve the quality and safety of malt. PMID:10405796

  6. Gaussian approximation in the theory of MR signal formation in the presence of structure-specific magnetic field inhomogeneities.

    PubMed

    Sukstanskii, Alexander L; Yablonskiy, Dmitriy A

    2003-08-01

    A detailed theoretical analysis of the free induction decay (FID) and spin echo (SE) MR signal formation in the presence of mesoscopic structure-specific magnetic field inhomogeneities is developed in the framework of the Gaussian phase distribution approximation. The theory takes into account diffusion of nuclear spins in inhomogeneous magnetic fields created by arbitrarily shaped magnetized objects with permeable boundaries. In the short-time limit the FID signal decays quadratically with time and depends on the objects' geometry only through the volume fraction, whereas the SE signal decays as 5/2 power of time with the coefficient depending on both the volume fraction of the magnetized objects and their surface-to-volume ratio. In the motional narrowing regime, the FID and SE signals for objects of finite size decay mono-exponentially; a simple general expression is obtained for the relaxation rate constant deltaR2. In the case of infinitely long cylinders in the motional narrowing regime the theory predicts non-exponential signal decay lnS approximately -tlnt in accordance with previous results. For specific geometries of the objects (spheres and infinitely long cylinders) exact analytical expressions for the FID and SE signals are given. The theory can be applied, for instance, to biological systems where mesoscopic magnetic field inhomogeneities are induced by deoxygenated red blood cells, capillary network, contrast agents, etc. PMID:12914839

  7. Settling Velocity Specific SOC Distribution along Hillslopes - A field investigation in Denmark

    NASA Astrophysics Data System (ADS)

    Kuhn, N. J.; Hu, Y.

    2015-12-01

    The net effects of soil erosion by water, as a sink or source of atmospheric CO2, are decisively affected by the spatial re-distribution and stability of eroded soil organic carbon (SOC). The deposition position of eroded SOC, into terrestrial or aquatic systems, is actually decided by the transport distances of soil fractions where the SOC is stored. In theory, the transport distances of aggregated soil fractions are related to their settling velocities under given layer conditions. Yet, little field investigation has been conducted to examine the actual movement of eroded soil fractions along hillslopes, let alone the re-distribution pattern of functional SOC fractions. Eroding sandy soils and sediment were sampled after a series of rainfall events from different topographic positions along a slope on a freshly seeded cropland in Jutland, Denmark. All the soil samples from difference topographic positions along the slope were fractionated into five settling classes using a settling tube apparatus. The SOC content, 13C signature, and C:N ratios of all settling fractions were measured. Our results show that: 1) the spatial distribution of soil settling classes along the slope clearly shows a coarsening effect at the deposition area immediately below the eroding slope, followed by a fining trend on the deposition area at the slope tail. This proves the validity of the conceptual model in Starr et al. 2000 to predict SOC redistribution patterns along eroding hillslopes. 2) The isotopically enriched 13C on the slope back suggests greater decomposition rates possibly experienced by eroded SOC during transport, while the pronounced respiration rates at the slope tail indicate a great potential of CO2 emissions after deposition. Overall, our results illustrate that immediate deposition of fast settling soil fractions, and the thus induced preferential deposition of SOC at foot slope and potential CO2 emissions during transport, must be appropriately accounted for in

  8. Tonotopic and Field-Specific Representation of Long-Lasting Sustained Activity in Rat Auditory Cortex.

    PubMed

    Shiramatsu, Tomoyo I; Noda, Takahiro; Akutsu, Kan; Takahashi, Hirokazu

    2016-01-01

    Cortical information processing of the onset, offset, and continuous plateau of an acoustic stimulus should play an important role in acoustic object perception. To date, transient activities responding to the onset and offset of a sound have been well investigated and cortical subfields and topographic representation in these subfields, such as place code of sound frequency, have been well characterized. However, whether these cortical subfields with tonotopic representation are inherited in the sustained activities that follow transient activities and persist during the presentation of a long-lasting stimulus remains unknown, because sustained activities do not exhibit distinct, reproducible, and time-locked responses in their amplitude to be characterized by grand averaging. To address this gap in understanding, we attempted to decode sound information from densely mapped sustained activities in the rat auditory cortex using a sparse parameter estimation method called sparse logistic regression (SLR), and investigated whether and how these activities represent sound information. A microelectrode array with a grid of 10 × 10 recording sites within an area of 4.0 mm × 4.0 mm was implanted in the fourth layer of the auditory cortex in rats under isoflurane anesthesia. Sustained activities in response to long-lasting constant pure tones were recorded. SLR then was applied to discriminate the sound-induced band-specific power or phase-locking value from those of spontaneous activities. The highest decoding performance was achieved in the high-gamma band, indicating that cortical inhibitory interneurons may contribute to the sparse tonotopic representation in sustained activities by mediating synchronous activities. The estimated parameter in the SLR decoding revealed that the informative recording site had a characteristic frequency close to the test frequency. In addition, decoding of the four test frequencies demonstrated that the decoding performance of the SLR

  9. Tonotopic and Field-Specific Representation of Long-Lasting Sustained Activity in Rat Auditory Cortex

    PubMed Central

    Shiramatsu, Tomoyo I.; Noda, Takahiro; Akutsu, Kan; Takahashi, Hirokazu

    2016-01-01

    Cortical information processing of the onset, offset, and continuous plateau of an acoustic stimulus should play an important role in acoustic object perception. To date, transient activities responding to the onset and offset of a sound have been well investigated and cortical subfields and topographic representation in these subfields, such as place code of sound frequency, have been well characterized. However, whether these cortical subfields with tonotopic representation are inherited in the sustained activities that follow transient activities and persist during the presentation of a long-lasting stimulus remains unknown, because sustained activities do not exhibit distinct, reproducible, and time-locked responses in their amplitude to be characterized by grand averaging. To address this gap in understanding, we attempted to decode sound information from densely mapped sustained activities in the rat auditory cortex using a sparse parameter estimation method called sparse logistic regression (SLR), and investigated whether and how these activities represent sound information. A microelectrode array with a grid of 10 × 10 recording sites within an area of 4.0 mm × 4.0 mm was implanted in the fourth layer of the auditory cortex in rats under isoflurane anesthesia. Sustained activities in response to long-lasting constant pure tones were recorded. SLR then was applied to discriminate the sound-induced band-specific power or phase-locking value from those of spontaneous activities. The highest decoding performance was achieved in the high-gamma band, indicating that cortical inhibitory interneurons may contribute to the sparse tonotopic representation in sustained activities by mediating synchronous activities. The estimated parameter in the SLR decoding revealed that the informative recording site had a characteristic frequency close to the test frequency. In addition, decoding of the four test frequencies demonstrated that the decoding performance of the SLR

  10. A Feasibility Study of a Field-specific Weather Service for Small-scale Farms in a Topographically Complex Watershed

    NASA Astrophysics Data System (ADS)

    Kim, S. O.; Shim, K. M.; Shin, Y. S.; Yun, J. I.

    2015-12-01

    Adequate downscaling of synoptic forecasts is a prerequisite for improved agrometeorological service to rural areas in South Korea where complex terrain and small farms are common. Geospatial schemes based on topoclimatology were used to scale down the Korea Meteorological Administration (KMA) temperature forecasts to the local scale (~30 m) across a rural catchment. Local temperatures were estimated at 14 validation sites at 0600 and 1500 LST in 2013/2014 using these schemes and were compared with observations. A substantial reduction in the estimation error was found for both 0600 and 1500 temperatures compared with uncorrected KMA products. Improvement was most remarkable at low lying locations for the 0600 temperature and at the locations on west- and south-facing slopes for the 1500 temperature. Using the downscaled real-time temperature data, a pilot service has started to provide field-specific weather information tailored to meet the requirements of small-scale farms. For example, the service system makes a daily outlook on the phenology of crop species grown in a given field using the field-specific temperature data. When the temperature forecast is given for tomorrow morning, a frost risk index is calculated according to a known phenology-frost injury relationship. If the calculated index is higher than a pre-defined threshold, a warning is issued and delivered to the grower's cellular phone with relevant countermeasures to help protect crops against frost damage. The system was implemented for a topographically complex catchment of 350km2with diverse agricultural activities, and more than 400 volunteer farmers are participating in this pilot service to access user-specific weather information.

  11. Characterisation of neutron fields at Cernavoda NPP.

    PubMed

    Cauwels, Vanessa; Vanhavere, Filip; Dumitrescu, Dorin; Chirosca, Alecsandru; Hager, Luke; Million, Marc; Bartz, James

    2013-04-01

    Near a nuclear reactor or a fuel container, mixed neutron/gamma fields are very common, necessitating routine neutron dosimetry. Accurate neutron dosimetry is complicated by the fact that the neutron effective dose is strongly dependent on the neutron energy and the direction distribution of the neutron fluence. Neutron field characterisation is indispensable if one wants to obtain a reliable estimate for the neutron dose. A measurement campaign at CANDU nuclear power plant located in Cernavoda, Romania, was set up to characterise the neutron fields in four different locations and to investigate the behaviour of different neutron personal dosemeters. This investigation intends to assist in choosing a suitable neutron dosimetry system at this nuclear power plant. PMID:22874895

  12. Efficacy of a piglet-specific commercial inactivated vaccine against Porcine circovirus type 2 in clinical field trials

    PubMed Central

    Han, Kiwon; Seo, Hwi Won; Oh, Yeonsu; Park, Changhoon; Kang, Ikjae; Jang, Hyun; Chae, Chanhee

    2013-01-01

    The efficacy of a piglet-specific inactivated Porcine circovirus type 2 (PCV2) vaccine was evaluated with clinical field trials, as recommended by the Republic of Korea’s Animal, Plant & Fisheries Quarantine & Inspection Agency. Three farms were selected on the basis of their history of postweaning multisystemic wasting syndrome. On each farm 60, 1-week-old pigs were randomly allocated to 1 of 2 treatment groups: vaccination at 1 and 3 wk of age or no vaccination. The 2-dose schedule of vaccination with inactivated PCV2 vaccine improved the average daily weight gain from birth to 16 wk of age, the PCV2 load in the blood, and the frequency and severity of lymph node lesions. Inactivated PCV2 vaccine seems to be very effective in controlling PCV2 infection under field conditions. PMID:24101803

  13. Minimizing the magnetic field effect in MR-linac specific QA-tests: the use of electron dense materials

    NASA Astrophysics Data System (ADS)

    van Zijp, H. M.; van Asselen, B.; Wolthaus, J. W. H.; Kok, J. M. G.; de Vries, J. H. W.; Ishakoglu, K.; Beld, E.; Lagendijk, J. J. W.; Raaymakers, B. W.

    2016-02-01

    To address the quality assurance (QA) of a MR-linac which is an MRI combined with a linear accelerator (linac), the traditional linac QA-tests need to be redesigned, since the presence of the static magnetic field in the MR-linac alters the electron trajectory. The latter causes the asymmetry in the dose kernel which is introduced by the magnetic field and hinders accurate geometrical QA-tests for the MR-linac. We introduced the use of electron dense materials (e.g. copper) to reduce the size of the dose kernel and thereby the magnetic field effect on the dose deposition. Two examples of QA-tests are presented in which the geometrical accuracy of the MR-linac was addressed; beam profile and star-shot measurements. The introduced setup was compared with a reference setup and both were tested on a conventional and the MR-linac. The results showed that the symmetry of the recorded beam profile was restored in presence of the copper material and that the isocenter size of the MR-linac can be determined accurately with the introduced star-shot setup. The use of electron dense materials is not limited to the presented QA-tests but has a broad application for beam-specific QA-tests in presence of a magnetic field.

  14. Microelectrode mapping of tonotopic, laminar, and field-specific organization of thalamo-cortical pathway in rat.

    PubMed

    Shiramatsu, Tomoyo Isoguchi; Takahashi, Kazusa; Noda, Takahiro; Kanzaki, Ryohei; Nakahara, Haruka; Takahashi, Hirokazu

    2016-09-22

    The rat has long been considered an important model system for studying neural mechanisms of auditory perception and learning, and particularly mechanisms involving auditory thalamo-cortical processing. However, the functional topography of the auditory thalamus, or medial geniculate body (MGB) has not yet been fully characterized in the rat, and the anatomically-defined features of field-specific, layer-specific and tonotopic thalamo-cortical projections have never been confirmed electrophysiologically. In the present study, we have established a novel technique for recording simultaneously from a surface microelectrode array on the auditory cortex, and a depth electrode array across auditory cortical layers and within the MGB, and characterized the rat MGB and thalamo-cortical projections under isoflurane anesthesia. We revealed that the ventral division of the MGB (MGv) exhibited a low-high-low CF gradient and long-short-long latency gradient along the dorsolateral-to-ventromedial axis, suggesting that the rat MGv is divided into two subdivisions. We also demonstrated that microstimulation in the MGv elicited cortical activation in layer-specific, region-specific and tonotopically organized manners. To our knowledge, the present study has provided the first and most compelling electrophysiological confirmation of the anatomical organization of the primary thalamo-cortical pathway in the rat, setting the groundwork for further investigation. PMID:27329334

  15. Specific absorption rate dependence on temperature in magnetic field hyperthermia measured by dynamic hysteresis losses (ac magnetometry)

    NASA Astrophysics Data System (ADS)

    Garaio, Eneko; Sandre, Olivier; Collantes, Juan-Mari; Garcia, Jose Angel; Mornet, Stéphane; Plazaola, Fernando

    2015-01-01

    Magnetic nanoparticles (NPs) are intensively studied for their potential use for magnetic hyperthermia, a treatment that has passed a phase II clinical trial against severe brain cancer (glioblastoma) at the end of 2011. Their heating power, characterized by the ‘specific absorption rate (SAR)’, is often considered temperature independent in the literature, mainly because of the difficulties that arise from the measurement methodology. Using a dynamic magnetometer presented in a recent paper, we measure here the thermal dependence of SAR for superparamagnetic iron oxide (maghemite) NPs of four different size-ranges corresponding to mean diameters around 12 nm, 14 nm, 15 nm and 16 nm. The article reports a parametrical study extending from 10 to 60 {}^\\circ C in temperature, from 75 to 1031 kHz in frequency, and from 2 to 24 kA m-1 in magnetic field strength. It was observed that SAR values of smaller NPs decrease with temperature whereas for the larger sample (16 nm) SAR values increase with temperature. The measured variation of SAR with temperature is frequency dependent. This behaviour is fully explained within the scope of linear response theory based on Néel and Brown relaxation processes, using independent magnetic measurements of the specific magnetization and the magnetic anisotropy constant. A good quantitative agreement between experimental values and theoretical values is confirmed in a tri-dimensional space that uses as coordinates the field strength, the frequency and the temperature.

  16. Neutrons, gamma rays, and beta particles interactions with IIaO films flown on Astro I and Astro II and comparison with IIaO flown on the get-away-special STS-7

    SciTech Connect

    Hammond, E.C. Jr.; Peters, K.; Boone, K.

    1995-09-01

    The current requirements for the Laboratory for Astronomy and Solar Physics, sends rocket satellites and in the near future will involve flights in the shuttle to the upper reaches of the Earth`s atmosphere where they will be subjected to the atomic particles and electromagnetic radiation produced by the Sun and other cosmic radiation. It is therefore appropriate to examine the effect of neutrons, gamma rays, beta particles, and X-rays on the film currently being used by the Laboratory for current and future research requirements. It is also hoped by examining these particles in their effect that the authors will have simulated the space environment of the rockets, satellites, and shuttles. Several samples of the IIaO film were exposed to a neutron howitzer with a source energy of approximately 106 neutrons/steradians. They exposed several samples of the film to a 10 second blast of neutrons in both metal and plastic containers which exhibited higher density readings which indicated the possibility of some secondary nuclear interactions between neutrons and the aluminum container. The plastic container showed some variations at the higher densities. Exposure of the samples of IIaO film to a neutron beam of approximately 10 neutrons per steradians for eight minutes produces approximately a 13% difference in the density readings of the dark density grids. It is not noticeable that at the lighter density grid the neutrons have minimal effects, but on a whole the trend of the eight minute exposed IIaO film density grids at the darker end had a 7.1% difference than the control. Further analysis is anticipated by increasing the exposure time. Two sets of film were exposed to a beta source in a plastic container. The beta source was placed at the bottom so that the cone of rays striking the film would be conical for a period of seven days. It was observed in the films, designated 4a and 4b, a dramatic increase in the grid densities had occurred.

  17. Patient-Specific Quality Assurance for Prostate Cancer Patients Receiving Spot Scanning Proton Therapy Using Single-Field Uniform Dose

    SciTech Connect

    Zhu, X. Ronald; Poenisch, Falk; Song, Xiaofei; Johnson, Jennifer L.; Ciangaru, George; Taylor, M. Brad; Lii, Ming Fwu; Martin, Craig; Arjomandy, Bijan; Lee, Andrew K.; Choi, Seungtaek; Nguyen, Quynh nhu; Gillin, Michael T.; Sahoo, Narayan

    2011-10-01

    Purpose: To describe our experiences with patient-specific quality assurance (QA) for patients with prostate cancer receiving spot scanning proton therapy (SSPT) using single-field uniform dose (SFUD). Methods and Materials: The first group of 249 patients with prostate cancer treated with SSPT using SFUD was included in this work. The scanning-beam planning target volume and number of monitor units were recorded and checked for consistency. Patient-specific dosimetric measurements were performed, including the point dose for each plan, depth doses, and two-dimensional (2D) dose distribution in the planes perpendicular to the incident beam direction for each field at multiple depths. The {gamma}-index with 3% dose or 3-mm distance agreement criteria was used to evaluate the 2D dose distributions. Results: We observed a linear relationship between the number of monitor units and scanning-beam planning target volume. The difference between the measured and calculated point doses (mean {+-} SD) was 0.0% {+-} 0.7% (range, -2.9% to 1.8%). In general, the depth doses exhibited good agreement except at the distal end of the spread-out Bragg peak. The pass rate of {gamma}-index (mean {+-} SD) for 2D dose comparison was 96.2% {+-} 2.6% (range, 90-100%). Discrepancies between the measured and calculated dose distributions primarily resulted from the limitation of the model used by the treatment planning system. Conclusions: We have established a patient-specific QA program for prostate cancer patients receiving SSPT using SFUD.

  18. Combination neutron-gamma ray detector

    DOEpatents

    Stuart, Travis P.; Tipton, Wilbur J.

    1976-10-26

    A radiation detection system capable of detecting neutron and gamma events and distinguishing therebetween. The system includes a detector for a photomultiplier which utilizes a combination of two phosphor materials, the first of which is in the form of small glass beads which scintillate primarily in response to neutrons and the second of which is a plastic matrix which scintillates in response to gammas. A combination of pulse shape and pulse height discrimination techniques is utilized to provide an essentially complete separation of the neutron and gamma events.

  19. Estimation of variability of specific absorption rate with physical description of children exposed to electromagnetic field in the VHF band.

    PubMed

    Nagaoka, T; Watanabe, S

    2009-01-01

    Recently, there has been an increasing concern regarding the effects of electromagnetic waves on the health of humans. The safety of radio frequency electromagnetic fields (RF-EMFs) is evaluated by the specific absorption rate (SAR). In recent years, SAR has been estimated by numerical simulation using fine-resolution and anatomically realistic reference whole-body voxel models of people of various ages. The variation in SAR with a change in the physical features of a real person is hardly studied, although every person has different physical features. In this study, in order to estimate the individual variability in SAR of persons, we obtained considerable 3D body shape data from actual three-year-old children and developed several homogeneous models of these children. The variability in SAR of the homogeneous models of three-year-old children for whole-body exposure to RF electromagnetic fields in the very high frequency (VHF) band calculated using the finite-difference time-domain method has been described. PMID:19964253

  20. Recent Results From Internal and Very-Near-Field Plasma Diagnostics of a High Specific Impulse Hall Thruster

    NASA Technical Reports Server (NTRS)

    Hofer, Richard R.; Gallimore, Alec D.; Jacobson, David (Technical Monitor)

    2003-01-01

    Floating potential and ion current density measurements were taken on the laboratory model NASA-173Mv2 in order to improve understanding of the physical processes affecting Hall thruster performance at high specific impulse. Floating potential was measured on discharge chamber centerline over axial positions spanning 10 mm from the anode to 100 mm downstream of the exit plane. Ion current density was mapped radially up to 300 mm from thruster centerline over axial positions in the very-near-field (10 to 250 mm from the exit plane). All data were collected using a planar probe in conjunction with a high-speed translation stage to minimize probe-induced thruster perturbations. Measurements of floating potential at a xenon flow rate of 10 mg/s have shown that the acceleration layer moved upstream 3 1 mm when the voltage increased from 300 to 600 V. The length of the acceleration layer was 14 2 mm and was approximately constant with voltage and magnetic field. Ion current density measurements indicated the annular ion beam crossed the thruster centerline 163 mm downstream of the exit plane. Radial integration of the ion current density at the cathode plane provided an estimate of the ion current fraction. At 500 V and 5 mg/s, the ion current fraction was calculated as 0.77.

  1. Time-specific measurements of energy deposition from radiation fields in simulated sub-micron tissue volumes

    SciTech Connect

    Famiano, M.A.

    1997-07-07

    A tissue-equivalent spherical proportional counter is used with a modified amplifier system to measure specific energy deposited from a uniform radiation field for short periods of time ({approximately}1 {micro}s to seconds) in order to extrapolate to dose in sub-micron tissue volumes. The energy deposited during these time intervals is compared to biological repair processes occurring within the same intervals after the initial energy deposition. The signal is integrated over a variable collection time which is adjusted with a square-wave pulse. Charge from particle passages is collected on the anode during the period in which the integrator is triggered, and the signal decays quickly to zero after the integrator feedback switch resets; the process repeats for every triggering pulse. Measurements of energy deposited from x rays, {sup 137}Cs gamma rays, and electrons from a {sup 90}Sr/{sup 90}Y source for various time intervals are taken. Spectral characteristics as a function of charge collection time are observed and frequency plots of specific energy and collection time-interval are presented. In addition, a threshold energy flux is selected for each radiation type at which the formation of radicals (based on current measurements) in mammalian cells equals the rate at which radicals are repaired.

  2. Protein-specific force field derived from the fragment molecular orbital method can improve protein-ligand binding interactions.

    PubMed

    Chang, Le; Ishikawa, Takeshi; Kuwata, Kazuo; Takada, Shoji

    2013-05-30

    Accurate computational estimate of the protein-ligand binding affinity is of central importance in rational drug design. To improve accuracy of the molecular mechanics (MM) force field (FF) for protein-ligand simulations, we use a protein-specific FF derived by the fragment molecular orbital (FMO) method and by the restrained electrostatic potential (RESP) method. Applying this FMO-RESP method to two proteins, dodecin, and lysozyme, we found that protein-specific partial charges tend to differ more significantly from the standard AMBER charges for isolated charged atoms. We did not see the dependence of partial charges on the secondary structure. Computing the binding affinities of dodecin with five ligands by MM PBSA protocol with the FMO-RESP charge set as well as with the standard AMBER charges, we found that the former gives better correlation with experimental affinities than the latter. While, for lysozyme with five ligands, both charge sets gave similar and relatively accurate estimates of binding affinities. PMID:23420697

  3. Field surveys reveal the presence of anti-androgens in an effluent-receiving river using stickleback-specific biomarkers.

    PubMed

    Katsiadaki, Ioanna; Sanders, Matthew B; Henrys, Peter A; Scott, Alexander P; Matthiessen, Peter; Pottinger, Tom G

    2012-10-15

    This study was designed to assess whether the removal of endocrine disrupting chemicals (EDCs) and other substances from a Waste Water Treatment Works (WWTW) effluent (receiving water: R. Ray, Swindon, UK) by granular activated carbon (GAC) affected biomarkers of exposure to EDCs [vitellogenin (VTG) and spiggin] in male and female three-spined sticklebacks in the receiving water. A nearby river (R. Ock), with a negligible effluent loading, was used as a control. On each river fish were sampled from four sites on five occasions both before and after remediation of the WWTW effluent. The results show for the first time in a UK field study a clear seasonality of blood VTG concentrations in wild male fish, following closely the VTG profile in female fish from both rivers. VTG levels in male fish from the R. Ray were significantly reduced after the GAC installation. However, VTG levels in males from the control sites also varied significantly across the same period, reducing the significance of this finding. A laboratory exposure to oestradiol (using site-specific lower and upper levels of oestrogenic activity) failed to elevate VTG concentrations in male sticklebacks suggesting that concentrations in the effluent, even prior to remediation, may not have exceeded a critical sensitivity threshold. Most importantly, a significant increase in female kidney spiggin content (a highly specific biomarker of xeno-androgen exposure) occurred in fish in the R. Ray after the GAC installation to levels comparable with those in fish from the control river. The significance of this finding is strengthened by the fact that during the pre-remediation period in the R. Ray, female spiggin levels increased with increasing distance from the WWTW. Our results provide the first in vivo evidence of the presence of anti-androgens in a UK WWTW effluent. To our knowledge this is the first UK-based comprehensive field study on the effects of a WWTW upgrade on biomarkers of EDC exposure using a

  4. Application of magnetic field hyperthermia and superparamagnetic iron oxide nanoparticles to HIV-1-specific T-cell cytotoxicity

    PubMed Central

    Williams, James P; Southern, Paul; Lissina, Anya; Christian, Helen C; Sewell, Andrew K; Phillips, Rodney; Pankhurst, Quentin; Frater, John

    2013-01-01

    The latent HIV-1 reservoir remains the major barrier to HIV-1 eradication. Although successful at limiting HIV replication, highly active antiretroviral therapy is unable to cure HIV infection, thus novel therapeutic strategies are needed to eliminate the virus. Magnetic field hyperthermia (MFH) generates thermoablative cytotoxic temperatures in target-cell populations, and has delivered promising outcomes in animal models, as well as in several cancer clinical trials. MFH has been proposed as a strategy to improve the killing of HIV-infected cells and for targeting the HIV latent reservoirs. We wished to determine whether MFH could be used to enhance cytotoxic T-lymphocyte (CTL) targeting of HIV-infected cells in a proof-of-concept study. Here, for the first time, we apply MFH to an infectious disease (HIV-1) using the superparamagnetic iron oxide nanoparticle FeraSpin R. We attempt to improve the cytotoxic potential of T-cell receptor-transfected HIV-specific CTLs using thermotherapy, and assess superparamagnetic iron oxide nanoparticle toxicity, uptake, and effect on cell function using more sensitive methods than previously described. FeraSpin R exhibited only limited toxicity, demonstrated efficient uptake and cell-surface attachment, and only modestly impacted T-cell function. In contrast to the cancer models, insufficient MFH was generated to enhance CTL killing of HIV-infected cells. MFH remains an exciting new technology in the field of cancer therapeutics, which, as technology improves, may have significant potential to enhance CTL function and act as an adjunctive therapy in the eradication of latently infected HIV-positive cells. PMID:23901272

  5. Subject-specific modulation of local field potential spectral power during brain-machine interface control in primates

    NASA Astrophysics Data System (ADS)

    So, Kelvin; Dangi, Siddharth; Orsborn, Amy L.; Gastpar, Michael C.; Carmena, Jose M.

    2014-04-01

    Objective. Intracortical brain-machine interfaces (BMIs) have predominantly utilized spike activity as the control signal. However, an increasing number of studies have shown the utility of local field potentials (LFPs) for decoding motor related signals. Currently, it is unclear how well different LFP frequencies can serve as features for continuous, closed-loop BMI control. Approach. We demonstrate 2D continuous LFP-based BMI control using closed-loop decoder adaptation, which adapts decoder parameters to subject-specific LFP feature modulations during BMI control. We trained two macaque monkeys to control a 2D cursor in a center-out task by modulating LFP power in the 0-150 Hz range. Main results. While both monkeys attained control, they used different strategies involving different frequency bands. One monkey primarily utilized the low-frequency spectrum (0-80 Hz), which was highly correlated between channels, and obtained proficient performance even with a single channel. In contrast, the other monkey relied more on higher frequencies (80-150 Hz), which were less correlated between channels, and had greater difficulty with control as the number of channels decreased. We then restricted the monkeys to use only various sub-ranges (0-40, 40-80, and 80-150 Hz) of the 0-150 Hz band. Interestingly, although both monkeys performed better with some sub-ranges than others, they were able to achieve BMI control with all sub-ranges after decoder adaptation, demonstrating broad flexibility in the frequencies that could potentially be used for LFP-based BMI control. Significance. Overall, our results demonstrate proficient, continuous BMI control using LFPs and provide insight into the subject-specific spectral patterns of LFP activity modulated during control.

  6. Stabilization of lignin in soils - lessons from compound specific 13C analysis in long-term field experiments

    NASA Astrophysics Data System (ADS)

    Hofmann, A.; Heim, A.; Christensen, B. T.; Miltner, A.; Schmidt, M. W. I.

    2009-04-01

    A frequently cited assumption is that lignin in soils should be relatively stable due to its recalcitrant chemical structure. In recent years, this view has been challenged by new analytical techniques that use both lignin-specific biomarker molecules and compound specific isotope analysis. Applying these techniques to long-term field experiments with natural carbon isotopic labelling (C3-C4 vegetation change), it could be shown that the dynamics of lignin in soils are more complex and cannot be explained by its recalcitrant structure alone. In particular, there seem to be both a stable and a labile lignin pool in soils. As for soil organic carbon in general, interactions with the mineral phase have been suggested to be involved in the stabilization of lignin in soils. The present study focuses on the stable pool and tries to answer the following questions: (I) Which soil fractions contain most lignin? (II) Is the stable pool related to a particular soil fraction? (III) Can differences in lignin content between soil fractions be explained by properties of the mineral phase (surface area, type of minerals)? We used a combined density and aggregate size fractionation of an agricultural soil before and after it had been naturally 13C-labelled by 18 years of maize cropping. We identified old lignin deriving from the time before maize cropping by compound-specific isotope analysis of lignin-derived phenolic biomarkers. In the studied soil, we found a large proportion of lignin in coarse heavy fraction, suggesting inclusion in macroaggregates. However, isotope data indicated that lignin in this fraction was less stable in the long-term than lignin in light fractions. A potential explanation might be that some lignin-containing cell structures (e.g. thick cell walls) are recalcitrant enough to persist for decades even under intensive cropping. Due to intensive cropping before the isotopic labelling started, the light fractions would already be enriched in these structures

  7. Wireless hippocampal neural recording via a multiple input RF receiver to construct place-specific firing fields.

    PubMed

    Lee, Seung Bae; Manns, Joseph R; Ghovanloo, Maysam

    2012-01-01

    This paper reports scientifically meaningful in vivo experiments using a 32-channel wireless neural recording system (WINeR). The WINeR system is divided into transmitter (Tx) and receiver (Rx) parts. On the Tx side, we had WINeR-6, a system-on-a-chip (SoC) that operated based on time division multiplexing (TDM) of pulse width modulated (PWM) samples. The chip was fabricated in a 0.5-µm CMOS process, occupying 4.9 × 3.3 mm(2) and consuming 15 mW from ±1.5V supplies. The Rx used two antennas with separate pathways to down-convert the RF signal from a large area. A time-to-digital converter (TDC) in an FPGA converted the PWM pulses into digitized samples. In order to further increase the wireless coverage area and eliminate blind spots within a large experimental arena, two receivers were synchronized. The WINeR system was used to record epileptic activities from a rat that was injected with tetanus toxin (TT) in the dorsal hippocampus. In a different in vivo experiment, place-specific firing fields of place cells, which are parts of the hippocampal-dependent memory, were mapped from a series of behavioral experiments from a rat running in a circular track. Results from the same animal were compared against a commercial hard-wired recording system to evaluate the quality of the wireless recordings. PMID:23366004

  8. Magnetic field dependence of the magnetic susceptibility and the specific heat of the doped plasticized polyaniline (PANI-DB3EPSA)0.5.

    PubMed

    Djurado, D; Pron, A; Jacquot, J F; Travers, J P; Adriano, C; Vargas, J M; Pagliuso, P G; Rettori, C; Lesseux, G G; Fier, I; Walmsley, L

    2011-05-25

    Specific heat, magnetization and electron spin resonance (ESR) data obtained from a self-standing film of the doped plasticized polyaniline (PANI-DB3EPSA)(0.5) are shown. No long range magnetic order has been observed at zero magnetic field, above 2 K. For a magnetic field of 3.3 kOe applied perpendicular to the plane of the film, a clear signature of an induced ordered state can be seen in the specific heat data and ESR also reveals this antiferromagnetic order. An electronic contribution is detected from ESR, magnetization and specific heat; however, for T ≤ 5 K, the specific heat data show the existence of a gap. Magnetization data also show a low temperature dominant Curie behaviour which cannot be seen from ESR, probably due to a very large linewidth, suggesting short range correlations among spin 1/2 polarons. PMID:21540502

  9. Delineation of Management Zones for Site Specific Management of Parasitic Nematodes Using Geostatistical Analysis of Measured Field Characteristics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Delineation of management zones for site specific management of cotton-parasitic nematodes requires the study of their spatial and temporal variability. If the nematodes follow a spatial structure and this structure is correlated with the spatial variability of specific biotic or abiotic conditions ...

  10. Analgesic and behavioral effects of a 100 microT specific pulsed extremely low frequency magnetic field on control and morphine treated CF-1 mice.

    PubMed

    Shupak, Naomi M; Hensel, Jennifer M; Cross-Mellor, Shelly K; Kavaliers, Martin; Prato, Frank S; Thomas, Alex W

    2004-01-01

    Diverse studies have shown that magnetic fields can affect behavioral and physiological functions. Previously, we have shown that sinusoidal extremely low frequency magnetic fields and specific pulsed magnetic fields (Cnps) can produce alterations in the analgesia-related behavior of the land snail. Here, we have extended these studies to show an induction of analgesia in mice equivalent to a moderate dose of morphine (5 mg/kg), and the effect of both Cnp exposure and morphine injection on some open-field activity. Cnp exposure was found to prolong the response latency to a nociceptive thermal stimulus (hot plate). Cnp+morphine offset the increased movement activity found with morphine alone. These results suggest that pulsed magnetic fields can induce analgesic behavior in mice without the side effects often associated with opiates like morphine. PMID:14698475

  11. Specific Intensity Direct Current (DC) Electric Field Improves Neural Stem Cell Migration and Enhances Differentiation towards βIII-Tubulin+ Neurons

    PubMed Central

    Zhao, Huiping; Steiger, Amanda; Nohner, Mitch; Ye, Hui

    2015-01-01

    Control of stem cell migration and differentiation is vital for efficient stem cell therapy. Literature reporting electric field–guided migration and differentiation is emerging. However, it is unknown if a field that causes cell migration is also capable of guiding cell differentiation—and the mechanisms for these processes remain unclear. Here, we report that a 115 V/m direct current (DC) electric field can induce directional migration of neural precursor cells (NPCs). Whole cell patching revealed that the cell membrane depolarized in the electric field, and buffering of extracellular calcium via EGTA prevented cell migration under these conditions. Immunocytochemical staining indicated that the same electric intensity could also be used to enhance differentiation and increase the percentage of cell differentiation into neurons, but not astrocytes and oligodendrocytes. The results indicate that DC electric field of this specific intensity is capable of promoting cell directional migration and orchestrating functional differentiation, suggestively mediated by calcium influx during DC field exposure. PMID:26068466

  12. Field-scale Stability Assessment of Multi-year Spatiotemporal Variability in Cotton for the Site-specific Management of Tarnished Plant Bugs (Lygus ineolaris Palisot de Beauvois)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Site-specific management of Tarnished Plant Bug (TPB) infestations is dependent upon several factors contributing to field-scale variability that promote variations in cotton crop vigor. Six years of NDVI (Normalized Difference Vegetation Index) data (2001-2006) have been used to examine gradations ...

  13. The Influence of Current Density and Magnetic Field Topography in Optimizing the Performance, Divergence, and Plasma Oscillations of High Specific Impulse Hall Thrusters

    NASA Technical Reports Server (NTRS)

    Hofer, Richard R.; Jankovsky, Robert S.

    2003-01-01

    Recent studies of xenon Hall thrusters have shown peak efficiencies at specific impulses of less than 3000 s. This was a consequence of modern Hall thruster magnetic field topographies, which have been optimized for 300 V discharges. On-going research at the NASA Glenn Research Center is investigating this behavior and methods to enhance thruster performance. To conduct these studies, a laboratory model Hall thruster that uses a pair of trim coils to tailor the magnetic field topography for high specific impulse operation has been developed. The thruster-the NASA-173Mv2 was tested to determine how current density and magnetic field topography affect performance, divergence, and plasma oscillations at voltages up to 1000 V. Test results showed there was a minimum current density and optimum magnetic field topography at which efficiency monotonically increased with voltage. At 1000 V, 10 milligrams per second the total specific impulse was 3390 s and the total efficiency was 60.8%. Plume divergence decreased at 400-1000 V, but increased at 300-400 V as the result of plasma oscillations. The dominant oscillation frequency steadily increased with voltage, from 14.5 kHz at 300 V, to 22 kHz at 1000 V. An additional oscillatory mode in the 80-90 kHz frequency range began to appear above 500 V. The use of trim coils to modify the magnetic field improved performance while decreasing plume divergence and the frequency and magnitude of plasma oscillations.

  14. A sensitive, specific and reproducible real-time polymerase chain reaction method for detection of Plasmodium vivax and Plasmodium falciparum infection in field-collected anophelines.

    PubMed

    Bickersmith, Sara A; Lainhart, William; Moreno, Marta; Chu, Virginia M; Vinetz, Joseph M; Conn, Jan E

    2015-06-01

    We describe a simple method for detection of Plasmodium vivax and Plasmodium falciparum infection in anophelines using a triplex TaqMan real-time polymerase chain reaction (PCR) assay (18S rRNA). We tested the assay on Anopheles darlingi and Anopheles stephensi colony mosquitoes fed with Plasmodium-infected blood meals and in duplicate on field collected An. darlingi. We compared the real-time PCR results of colony-infected and field collected An. darlingi, separately, to a conventional PCR method. We determined that a cytochrome b-PCR method was only 3.33% as sensitive and 93.38% as specific as our real-time PCR assay with field-collected samples. We demonstrate that this assay is sensitive, specific and reproducible. PMID:26061150

  15. Magnetic field induced enlargement of the regime of critical fluctuations in the classical superconductor V3Si from high-resolution specific heat experiments.

    PubMed

    Zheng, Y; Liu, Y; Toyota, N; Lortz, R

    2015-02-25

    We present high-resolution specific heat data from a high-purity single crystal of the classical superconductor V(3)Si, which reveal tiny lambda-shape anomalies at the superconducting transition superimposed onto the BCS specific heat jump in magnetic fields of 2 T and higher. The appearance of these anomalies is accompanied by a magnetic-field-induced broadening of the superconducting transition. We demonstrate, using scaling relations predicted by the fluctuation models of the 3d-XY and the 3d-lowest-Landau-level (3d-LLL) universality class that the effect of critical fluctuations becomes experimentally observable due to of a magnetic field-induced enlargement of the regime of critical fluctuations. The scaling indicates that a reduction of the effective dimensionality due to the confinement of quasiparticles into low Landau levels is responsible for this effect. PMID:25640214

  16. Phylogenomics of Xanthomonas field strains infecting pepper and tomato reveals diversity in effector repertoires and identifies determinants of host specificity

    PubMed Central

    Schwartz, Allison R.; Potnis, Neha; Timilsina, Sujan; Wilson, Mark; Patané, José; Martins, Joaquim; Minsavage, Gerald V.; Dahlbeck, Douglas; Akhunova, Alina; Almeida, Nalvo; Vallad, Gary E.; Barak, Jeri D.; White, Frank F.; Miller, Sally A.; Ritchie, David; Goss, Erica; Bart, Rebecca S.; Setubal, João C.; Jones, Jeffrey B.; Staskawicz, Brian J.

    2015-01-01

    Bacterial spot disease of pepper and tomato is caused by four distinct Xanthomonas species and is a severely limiting factor on fruit yield in these crops. The genetic diversity and the type III effector repertoires of a large sampling of field strains for this disease have yet to be explored on a genomic scale, limiting our understanding of pathogen evolution in an agricultural setting. Genomes of 67 Xanthomonas euvesicatoria (Xe), Xanthomonas perforans (Xp), and Xanthomonas gardneri (Xg) strains isolated from diseased pepper and tomato fields in the southeastern and midwestern United States were sequenced in order to determine the genetic diversity in field strains. Type III effector repertoires were computationally predicted for each strain, and multiple methods of constructing phylogenies were employed to understand better the genetic relationship of strains in the collection. A division in the Xp population was detected based on core genome phylogeny, supporting a model whereby the host-range expansion of Xp field strains on pepper is due, in part, to a loss of the effector AvrBsT. Xp-host compatibility was further studied with the observation that a double deletion of AvrBsT and XopQ allows a host range expansion for Nicotiana benthamiana. Extensive sampling of field strains and an improved understanding of effector content will aid in efforts to design disease resistance strategies targeted against highly conserved core effectors. PMID:26089818

  17. Phylogenomics of Xanthomonas field strains infecting pepper and tomato reveals diversity in effector repertoires and identifies determinants of host specificity.

    PubMed

    Schwartz, Allison R; Potnis, Neha; Timilsina, Sujan; Wilson, Mark; Patané, José; Martins, Joaquim; Minsavage, Gerald V; Dahlbeck, Douglas; Akhunova, Alina; Almeida, Nalvo; Vallad, Gary E; Barak, Jeri D; White, Frank F; Miller, Sally A; Ritchie, David; Goss, Erica; Bart, Rebecca S; Setubal, João C; Jones, Jeffrey B; Staskawicz, Brian J

    2015-01-01

    Bacterial spot disease of pepper and tomato is caused by four distinct Xanthomonas species and is a severely limiting factor on fruit yield in these crops. The genetic diversity and the type III effector repertoires of a large sampling of field strains for this disease have yet to be explored on a genomic scale, limiting our understanding of pathogen evolution in an agricultural setting. Genomes of 67 Xanthomonas euvesicatoria (Xe), Xanthomonas perforans (Xp), and Xanthomonas gardneri (Xg) strains isolated from diseased pepper and tomato fields in the southeastern and midwestern United States were sequenced in order to determine the genetic diversity in field strains. Type III effector repertoires were computationally predicted for each strain, and multiple methods of constructing phylogenies were employed to understand better the genetic relationship of strains in the collection. A division in the Xp population was detected based on core genome phylogeny, supporting a model whereby the host-range expansion of Xp field strains on pepper is due, in part, to a loss of the effector AvrBsT. Xp-host compatibility was further studied with the observation that a double deletion of AvrBsT and XopQ allows a host range expansion for Nicotiana benthamiana. Extensive sampling of field strains and an improved understanding of effector content will aid in efforts to design disease resistance strategies targeted against highly conserved core effectors. PMID:26089818

  18. Improving the specificity of R2' to the deoxyhaemoglobin content of brain tissue: Prospective correction of macroscopic magnetic field gradients.

    PubMed

    Blockley, Nicholas P; Stone, Alan J

    2016-07-15

    The reversible transverse relaxation rate, R2', is sensitive to the deoxyhaemoglobin content of brain tissue, enabling information about the oxygen extraction fraction to be obtained. However, R2' is also sensitive to macroscopic magnetic field gradients, particularly at air-tissue interfaces where a large susceptibility difference is present. It is important that this latter effect is minimised in order to produce meaningful estimates of blood oxygenation. Therefore, the aim of this study was to implement a technique to prospectively correct for the effect of susceptibility induced magnetic field gradients on R2' weighted data. This was achieved by combining the Gradient-Echo Slice Excitation Profile Imaging (GESEPI) technique with an Asymmetric Spin Echo (ASE) pulse sequence. The main advantages of this approach are (i) shorter acquisition times, since a separately acquired magnetic field map is not required and (ii) simpler analysis, since retrospective correction for the effects of magnetic field gradients in postprocessing is not required. In these experiments we show that with this newly developed technique it is possible to correct the majority of grey matter voxels for the expected distribution of through-slice magnetic field gradients to produce maps of R2' in a short scan duration. PMID:27150229

  19. A field-based method to derive macroinvertebrate benchmark for specific conductivity adapted for small data sets and demonstrated in the Hun-Tai River Basin, Northeast China.

    PubMed

    Zhao, Qian; Jia, Xiaobo; Xia, Rui; Lin, Jianing; Zhang, Yuan

    2016-09-01

    Ionic mixtures, measured as specific conductivity, have been increasingly concerned because of their toxicities to aquatic organisms. However, identifying protective values of specific conductivity for aquatic organisms is challenging given that laboratory test systems cannot examine more salt-intolerant species nor effects occurring in streams. Large data sets used for deriving field-based benchmarks are rarely available. In this study, a field-based method for small data sets was used to derive specific conductivity benchmark, which is expected to prevent the extirpation of 95% of local taxa from circum-neutral to alkaline waters dominated by a mixture of SO4(2-) and HCO3(-) anions and other dissolved ions. To compensate for the smaller sample size, species level analyses were combined with genus level analyses. The benchmark is based on extirpation concentration (XC95) values of specific conductivity for 60 macroinvertebrate genera estimated from 296 sampling sites in the Hun-Tai River Basin. We derived the specific conductivity benchmark by using a 2-point interpolation method, which yielded the benchmark of 249 μS/cm. Our study tailored the method that was developed by USEPA to derive aquatic life benchmark for specific conductivity for basin scale application, and may provide useful information for water pollution control and management. PMID:27389551

  20. Specific features of attenuated light transmission by liquid-crystal twist cells in constant and alternating electric fields

    NASA Astrophysics Data System (ADS)

    Konshina, E. A.; Amosova, L. P.

    2012-07-01

    Optical transmission characteristics of dual-frequency nematic liquid crystal (NLC) twist cells with different alignment layers (rubbed polyimide and obliquely deposited cerium dioxide) have been studied in constant and alternating electric fields. It has been established that a change in the optical (twist effect) threshold and dynamic range of attenuated transmission depend both on the boundary conditions (that influence the screening of applied voltage) and on the parameters of the applied electric field. The maximum dynamic range (49.5 dB) has been obtained in the cell with a CeO2 alignment layer controlled by a constant potential. In the case of an alternating electric field, the dynamic range decreases because of reduced effective voltage.

  1. Neutron Reference Benchmark Field Specifications: ACRR Polyethylene-Lead-Graphite (PLG) Bucket Environment (ACRR-PLG-CC-32-CL).

    SciTech Connect

    Vega, Richard Manuel; Parm, Edward J.; Griffin, Patrick J.; Vehar, David W.

    2015-07-01

    This report was put together to support the International Atomic Energy Agency (IAEA) REAL- 2016 activity to validate the dosimetry community’s ability to use a consistent set of activation data and to derive consistent spectral characterizations. The report captures details of integral measurements taken in the Annular Core Research Reactor (ACRR) central cavity with the Polyethylene-Lead-Graphite (PLG) bucket, reference neutron benchmark field. The field is described and an “a priori” calculated neutron spectrum is reported, based on MCNP6 calculations, and a subject matter expert (SME) based covariance matrix is given for this “a priori” spectrum. The results of 37 integral dosimetry measurements in the neutron field are reported.

  2. A method to measure specific absorption rate of nanoparticles in colloidal suspension using different configurations of radio-frequency fields.

    PubMed

    Ketharnath, Dhivya; Pande, Rohit; Xie, Leiming; Srinivasan, Srimeenakshi; Godin, Biana; Wosik, Jarek

    2012-08-20

    We report a method for characterization of the efficiency of radio-frequency (rf) heating of nanoparticles (NPs) suspended in an aqueous medium. Measurements were carried out for water suspended 5 nm superparamagnetic iron-oxide NPs with 30 nm dextran matrix for three different configurations of rf electric and magnetic fields. A 30 MHz high-Q resonator was designed to measure samples placed inside a parallel plate capacitor and solenoid coil with or without an rf electric field shield. All components of rf losses were analyzed and rf electric and magnetic field induced heating of NPs and the dispersion medium was determined and discussed. PMID:22991480

  3. Ion Voltage Diagnostics in the Far-Field Plume of a High-Specific Impulse Hall Thruster

    NASA Technical Reports Server (NTRS)

    Hofer, Richard R.; Haas, James M.; Gallimore, Alec D.

    2003-01-01

    The effects of the magnetic field and discharge voltage on the far-field plume of the NASA 173Mv2 laboratory-model Hall thruster were investigated. A cylindrical Langmuir probe was used to measure the plasma potential and a retarding potential analyzer was employed to measure the ion voltage distribution. The plasma potential was affected by relatively small changes in the external magnetic field, which suggested a means to control the plasma surrounding the thruster. As the discharge voltage increased, the ion voltage distribution showed that the acceleration efficiency increased and the dispersion efficiency decreased. This implied that the ionization zone was growing axially and moving closer to the anode, which could have affected thruster efficiency and lifetime due to higher wall losses. However, wall losses may have been reduced by improved focusing efficiency since the total efficiency increased and the plume divergence decreased with discharge voltage.

  4. Ultra-high field NMR studies of antibody binding and site-specific phosphorylation of {alpha}-synuclein

    SciTech Connect

    Sasakawa, Hiroaki |; Sakata, Eri; Yamaguchi, Yoshiki; Masuda, Masami |; Mori, Tetsuya; Kurimoto, Eiji; Iguchi, Takeshi; Hisanaga, Shin-ichi; Iwatsubo, Takeshi; Hasegawa, Masato; Kato, Koichi |

    2007-11-23

    Although biological importance of intrinsically disordered proteins is becoming recognized, NMR analyses of this class of proteins remain as tasks with more challenge because of poor chemical shift dispersion. It is expected that ultra-high field NMR spectroscopy offers improved resolution to cope with this difficulty. Here, we report an ultra-high field NMR study of {alpha}-synuclein, an intrinsically disordered protein identified as the major component of the Lewy bodies. Based on NMR spectral data collected at a 920 MHz proton frequency, we performed epitope mapping of an anti-{alpha}-synuclein monoclonal antibody, and furthermore, characterized conformational effects of phosphorylation at Ser129 of {alpha}-synuclein.

  5. Specific features of electric field in the atmosphere and Radon emanations in Tunkin Basin of Baikal rift zone

    NASA Astrophysics Data System (ADS)

    Soloviev, S.; Loktev, D.

    2013-05-01

    Development of methods for diagnosing local crust encourages finding new ways for preventing hazardous geologic phenomena. Using measurements of several geophysical fields in addition to seismic methods enables to improve the existing methods and increase their reliability. In summer of 2009 and 2010, complex geophysical acquisition company was organized in the Tunkin Basin of the Baikal rift zone in South-Eastern Siberia, that runs 200 km to East-West from the southern tip of Baikal. Stationary observations were carried out in the central part of the Tunkin Basin, at the Geophysical observatory "I" of Institute of Solar-Terrestrial Physics of Siberian Branch of RAS and "II" near the Arshan settlement. Along with observations of microseismic noise and electric field variations in soil, there were performed measurements of electric field strength (Ez) in lowest atmosphere and volumetric activity of natural Radon in subsoil. Meteorological parameters were monitored with the use of DavisVantagePro meteorological stations. The analysis of observations showed that characteristic features of electric field in near-surface atmosphere are majorly defined by complex orography of the place and, consequently, by quickly changing meteorological conditions: thunderstorm activity and other mesometeorological events (with characteristic scale of tens of km and few hours long) in nearby rocks. The results of Ez(t) measurements performed under "good" weather conditions showed that the character of field variations depended on the local time with their maximum in daylight hours and minimum in the night. The analysis of Radon volumetric activity evidenced that its variations are influenced by atmospheric pressure and tides, and such influence is different at points "I" and "II". In particular, the tidal and atmospheric influence on Radon variations is more pronounced at "II" if compared to "I", which can be explained by locations of the registration points. Registration Point "II" is

  6. Monte Carlo study of the potential reduction in out-of-field dose using a patient-specific aperture in pencil beam scanning proton therapy

    PubMed Central

    Dowdell, S J; Clasie, B; Depauw, N; Metcalfe, P; Rosenfeld, A B; Kooy, H M; Flanz, J; Paganetti, H

    2012-01-01

    This study aimed at identifying the potential benefits of using a patient specific aperture in proton beam scanning. For this purpose an accurate Monte Carlo model of the pencil beam scanning (PBS) proton therapy (PT) treatment head at Massachusetts General Hospital (MGH) was developed based on an existing model of the passive double-scattering (DS) system. The Monte Carlo code specifies the treatment head at MGH with sub-millimeter accuracy. The code was configured based on the results of experimental measurements performed at MGH. This model was then used to compare out-of-field doses in simulated double-scattering (DS) treatments and PBS treatments For the conditions explored, the penumbra in PBS is wider than in DS, leading to higher absorbed doses and equivalent doses adjacent to the primary field edge. For lateral distances greater than 10cm from the field edge, the doses in PBS appear to be lower than those observed for DS. We found that placing a patient-specific aperture at nozzle exit during PBS treatments can potentially reduce doses lateral to the primary radiation field by over an order of magnitude. In conclusion, using a patient-specific aperture has the potential to further improve the normal tissue sparing capabilities of PBS. PMID:22513726

  7. Conversion of upland to paddy field specifically alters the community structure of archaeal ammonia oxidizers in an acid soil

    NASA Astrophysics Data System (ADS)

    Alam, M. S.; Ren, G. D.; Lu, L.; Zheng, Y.; Peng, X. H.; Jia, Z. J.

    2013-08-01

    The function of ammonia-oxidizing archaea (AOA) and bacteria (AOB) depends on the major energy-generating compounds (i.e., ammonia and oxygen). The diversification of AOA and AOB communities along ecological gradients of substrate availability in a complex environment have been much debated but rarely tested. In this study, two ecosystems of maize and rice crops under different fertilization regimes were selected to investigate the community diversification of soil AOA and AOB upon conversion of an upland field to a paddy field and long-term field fertilization in an acid soil. Real-time quantitative polymerase chain reaction of ammonia monooxygenase (amoA) genes demonstrated that the abundance of AOA was significantly stimulated after conversion of upland to paddy soils for more than 100 yr, whereas a slight decline in AOB numbers was observed. Denaturing gradient gel electrophoresis fingerprints of amoA genes further revealed remarkable changes in the community compositions of AOA after conversion of aerobic upland to flooded paddy field. Sequencing analysis revealed that upland soil was dominated by AOA within the soil group 1.1b lineage, whereas the marine group 1.1a-associated lineage predominated in AOA communities in paddy soils. Irrespective of whether the soil was upland or paddy soil, long-term field fertilization led to increased abundance of amoA genes in AOA and AOB compared with control treatments (no fertilization), whereas archaeal amoA gene abundances outnumbered their bacterial counterparts in all samples. Phylogenetic analyses of amoA genes showed that Nitrosospira cluster-3-like AOB dominated bacterial ammonia oxidizers in both paddy and upland soils, regardless of fertilization treatment. The results of this study suggest that the marine group 1.1a-associated AOA will be better adapted to the flooded paddy field than AOA ecotypes of the soil group 1.1b lineage, and indicate that long-term flooding is the dominant selective force driving the

  8. Crystal symmetry and high-magnetic-field specific heat of SrCu{sub 2}(BO{sub 3}){sub 2}

    SciTech Connect

    Jorge, G.A.; Jaime, M.; Harrison, N.; Stern, R.; Bonca, J.; El Shawish, S.; Batista, C.D.; Dabkowska, H.A.; Gaulin, B.D.

    2005-03-01

    We report measurements of the specific heat of the quantum spin liquid system SrCu{sub 2}(BO{sub 3}){sub 2} in continuous magnetic fields H of up to 33 T. The specific heat data, when combined with a finite temperature Lanczos diagonalization of the Shastry-Sutherland Hamiltonian, indicate the presence of a nearest neighbor Dzyaloshinsky-Moriya (DM) interaction that violates the crystal symmetry. Moreover, the same DM interaction is required to explain the observed electron spin resonance lines for H parallel c.

  9. Preliminary Observations on Sensitivity and Specificity of Magnetization Transfer Asymmetry for Imaging Myelin of Rat Brain at High Field

    PubMed Central

    Kim, Jae-Woong; Choi, Jiye; Cho, Janggeun; Lee, Chulhyun; Jeon, Daejong; Park, Sung-Hong

    2015-01-01

    Magnetization transfer ratio (MTR) has been often used for imaging myelination. Despite its high sensitivity, the specificity of MTR to myelination is not high because tissues with no myelin such as muscle can also show high MTR. In this study, we propose a new magnetization transfer (MT) indicator, MT asymmetry (MTA), as a new method of myelin imaging. The experiments were performed on rat brain at 9.4 T. MTA revealed high signals in white matter and significantly low signals in gray matter and muscle, indicating that MTA has higher specificity than MTR. Demyelination and remyelination studies demonstrated that the sensitivity of MTA to myelination was as high as that of MTR. These experimental results indicate that MTA can be a good biomarker for imaging myelination. In addition, MTA images can be efficiently acquired with an interslice MTA method, which may accelerate clinical application of myelin imaging. PMID:26413534

  10. Analysis of in situ electric field and specific absorption rate in human models for wireless power transfer system with induction coupling.

    PubMed

    Sunohara, Tetsu; Hirata, Akimasa; Laakso, Ilkka; Onishi, Teruo

    2014-07-21

    This study investigates the specific absorption rate (SAR) and the in situ electric field in anatomically based human models for the magnetic field from an inductive wireless power transfer system developed on the basis of the specifications of the wireless power consortium. The transfer system consists of two induction coils covered by magnetic sheets. Both the waiting and charging conditions are considered. The transfer frequency considered in this study is 140 kHz, which is within the range where the magneto-quasi-static approximation is valid. The SAR and in situ electric field in the chest and arm of the models are calculated by numerically solving the scalar potential finite difference equation. The electromagnetic modelling of the coils in the wireless power transfer system is verified by comparing the computed and measured magnetic field distributions. The results indicate that the peak value of the SAR averaged over a 10 g of tissue and that of the in situ electric field are 72 nW kg(-1) and 91 mV m(-1) for a transmitted power of 1 W, Consequently, the maximum allowable transmitted powers satisfying the exposure limits of the SAR (2 W kg(-1)) and the in situ electric field (18.9 V m(-1)) are found to be 28 MW and 43 kW. The computational results show that the in situ electric field in the chest is the most restrictive factor when compliance with the wireless power transfer system is evaluated according to international guidelines. PMID:24936747

  11. Accurate Calculation of Hydration Free Energies using Pair-Specific Lennard-Jones Parameters in the CHARMM Drude Polarizable Force Field

    PubMed Central

    Baker, Christopher M.; Lopes, Pedro E. M.; Zhu, Xiao; Roux, Benoît; MacKerell, Alexander D.

    2010-01-01

    Lennard-Jones (LJ) parameters for a variety of model compounds have previously been optimized within the CHARMM Drude polarizable force field to reproduce accurately pure liquid phase thermodynamic properties as well as additional target data. While the polarizable force field resulting from this optimization procedure has been shown to satisfactorily reproduce a wide range of experimental reference data across numerous series of small molecules, a slight but systematic overestimate of the hydration free energies has also been noted. Here, the reproduction of experimental hydration free energies is greatly improved by the introduction of pair-specific LJ parameters between solute heavy atoms and water oxygen atoms that override the standard LJ parameters obtained from combining rules. The changes are small and a systematic protocol is developed for the optimization of pair-specific LJ parameters and applied to the development of pair-specific LJ parameters for alkanes, alcohols and ethers. The resulting parameters not only yield hydration free energies in good agreement with experimental values, but also provide a framework upon which other pair-specific LJ parameters can be added as new compounds are parametrized within the CHARMM Drude polarizable force field. Detailed analysis of the contributions to the hydration free energies reveals that the dispersion interaction is the main source of the systematic errors in the hydration free energies. This information suggests that the systematic error may result from problems with the LJ combining rules and is combined with analysis of the pair-specific LJ parameters obtained in this work to identify a preliminary improved combining rule. PMID:20401166

  12. Ion Species Fractions in the Far-Field Plume of a High-Specific Impulse Hall Thruster

    NASA Technical Reports Server (NTRS)

    Hofer, Richard R.; Gallimore, Alec D.

    2003-01-01

    An ExB probe was used to measure the ion species fractions of Xe(+), Xe(2+), and Xe(3+) in the far-field plume of the NASA-173Mv2 laboratory-model Hall thruster. The thruster was operated at a constant xenon flow rate of 10 milligrams per second and discharge voltages of 300 to 900 V. The ExB probe was placed two meters downstream of the thruster exit plane on the thruster centerline. At a discharge voltage of 300 V, the species fractions of Xe(2+) and Xe(3+) were lower, but still consistent with, previous Hall thruster studies using other mass analyzers. Over discharge voltages of 300 to 900 V, the Xe(2+) species fractions increased from 0.04 to 0.12 and the Xe(3+) species fraction increased from 0.01 to 0.02.

  13. Investigating temporal field sampling strategies for site-specific calibration of three soil moisture-neutron intensity parameterisation methods

    NASA Astrophysics Data System (ADS)

    Iwema, J.; Rosolem, R.; Baatz, R.; Wagener, T.; Bogena, H. R.

    2015-07-01

    The Cosmic-Ray Neutron Sensor (CRNS) can provide soil moisture information at scales relevant to hydrometeorological modelling applications. Site-specific calibration is needed to translate CRNS neutron intensities into sensor footprint average soil moisture contents. We investigated temporal sampling strategies for calibration of three CRNS parameterisations (modified N0, HMF, and COSMIC) by assessing the effects of the number of sampling days and soil wetness conditions on the performance of the calibration results while investigating actual neutron intensity measurements, for three sites with distinct climate and land use: a semi-arid site, a temperate grassland, and a temperate forest. When calibrated with 1 year of data, both COSMIC and the modified N0 method performed better than HMF. The performance of COSMIC was remarkably good at the semi-arid site in the USA, while the N0mod performed best at the two temperate sites in Germany. The successful performance of COSMIC at all three sites can be attributed to the benefits of explicitly resolving individual soil layers (which is not accounted for in the other two parameterisations). To better calibrate these parameterisations, we recommend in situ soil sampled to be collected on more than a single day. However, little improvement is observed for sampling on more than 6 days. At the semi-arid site, the N0mod method was calibrated better under site-specific average wetness conditions, whereas HMF and COSMIC were calibrated better under drier conditions. Average soil wetness condition gave better calibration results at the two humid sites. The calibration results for the HMF method were better when calibrated with combinations of days with similar soil wetness conditions, opposed to N0mod and COSMIC, which profited from using days with distinct wetness conditions. Errors in actual neutron intensities were translated to average errors specifically to each site. At the semi-arid site, these errors were below the

  14. SU-D-304-06: Measurement of LET in Patient-Specific Proton Therapy Treatment Fields Using Optically Stimulated Luminescence Detectors

    SciTech Connect

    Granville, DA; Sahoo, N; Sawakuchi, GO

    2015-06-15

    Purpose: To investigate the use of optically stimulated luminescence (OSL) detectors (OSLDs) for measurements of dose-averaged linear energy transfer (LET) in patient-specific proton therapy treatment fields. Methods: We used Al{sub 2}O{sub 3}:C OSLDs made from the same material as commercially available nanoDot OSLDs from Landauer, Inc. We calibrated two parameters of the OSL signal as functions of LET in therapeutic proton beams: the ratio of the ultraviolet and blue emission intensities (UV/blue ratio) and the OSL curve shape. These calibration curves were created by irradiating OSLDs in passively scattered beams of known LET (0.96 to 3.91 keV/µm). The LET values were determined using a validated Monte Carlo model of the beamline. We then irradiated new OSLDs with the prescription dose (16 to 74 cGy absorbed dose to water) at the center of the spread-out Bragg peak (SOBP) of four patient-specific treatment fields. From readouts of these OSLDs, we determined both the UV/blue ratio and OSL curve shape parameters. Combining these parameters with the calibration curves, we were able to measure LET using the OSLDs. The measurements were compared to the theoretical LET values obtained from Monte Carlo simulations of the patient-specific treatments fields. Results: Using the UV/blue ratio parameter, we were able to measure LET within 3.8%, 6.2%, 5.6% and 8.6% of the Monte Carlo value for each of the patient fields. Similarly, using the OSL curve shape parameter, LET measurements agreed within 0.5%, 11.0%, 2.5% and 7.6% for each of the four fields. Conclusion: We have demonstrated a method to verify LET in patient-specific proton therapy treatment fields using OSLDs. The possibility of enhancing biological effectiveness of proton therapy treatment plans by including LET in the optimization has been previously shown. The LET verification method we have demonstrated will be useful in the quality assurance of such LET optimized treatment plans. DA Granville received

  15. Measurement of gamma field parameters in core with LEU fuel IRT-4M using TL detectors

    SciTech Connect

    Bily, T.

    2008-07-15

    Thermoluminescent dosimeters represent very useful tool for gamma fields parameters measurements at nuclear research reactors, especially at zero power ones. {sup 7}LiF:Mg,Ti and {sup 7}LiF:Mg,Cu,P type TL dosimeters enable determination of only gamma component in mixed neutron - gamma field. At VR-1 reactor operated within the Faculty of Nuclear Sciences and Physical Engineering at the Czech Technical University in Prague the integral characteristics of gamma rays field were investigated, especially its spatial distribution and time behaviour, i.e. the non-saturated delayed gamma ray emission influence. Measured spatial distributions were compared with monte carlo code MCNP5 calculations. Although MCNP cannot generate delayed gamma rays from fission, the relative gamma dose rate distribution is within {+-} 15% with measured values. The experiments were carried out with core configuration C1 consisting of LEU fuel IRT-4M (19.7 %). (author)

  16. Early auditory experience induces frequency-specific, adaptive plasticity in the forebrain gaze fields of the barn owl.

    PubMed

    Miller, G L; Knudsen, E I

    2001-05-01

    Binaural acoustic cues such as interaural time and level differences (ITDs and ILDs) are used by many species to determine the locations of sound sources. The relationship between cue values and locations in space is frequency dependent and varies from individual to individual. In the current study, we tested the capacity of neurons in the forebrain localization pathway of the barn owl to adjust their tuning for binaural cues in a frequency-dependent manner in response to auditory experience. Auditory experience was altered by raising young owls with a passive acoustic filtering device that caused frequency-dependent changes in ITD and ILD. Extracellular recordings were made in normal and device-reared owls to characterize frequency-specific ITD and ILD tuning in the auditory archistriatum (AAr), an output structure of the forebrain localization pathway. In device-reared owls, individual sites in the AAr exhibited highly abnormal, frequency-dependent variations in ITD tuning, and across the population of sampled sites, there were frequency-dependent shifts in the representation of ITD. These changes were in a direction that compensated for the acoustic effects of the device on ITD and therefore tended to restore a normal representation of auditory space. Although ILD tuning was degraded relative to normal at many sites in the AAr of device-reared owls, the representation of frequency-specific ILDs across the population of sampled sites was shifted in the adaptive direction. These results demonstrate that early auditory experience shapes the representation of binaural cues in the forebrain localization pathway in an adaptive, frequency-dependent manner. PMID:11353033

  17. Technical specifications of low-frequency radio identification bedload tracking from field experiments: Differences in antennas, tags and operators

    NASA Astrophysics Data System (ADS)

    Arnaud, F.; Piégay, H.; Vaudor, L.; Bultingaire, L.; Fantino, G.

    2015-06-01

    Low-frequency passive integrated transponders (PIT tags) have been increasingly used for tracking bedload transport in gravel-bed rivers. Prior studies have reported high recovery rates in small streams, while recovery rates remained much lower in large systems, in large part because of the limited reading distance of the tags (< 1 m). Some laboratory tests have identified controlling factors for detection ranges (tag and antenna size, tag orientation, burial, submergence, etc.). Beyond these tests, improving our understanding of PIT tag functioning, using different equipment within different environments, is still needed in order to select the most suitable device for each geomorphic context. We address this knowledge gap with technical specifications for a low-frequency radio identification (RFID) device by working for the first time with real fluvial constraints, i.e., the gravel deposits and the aquatic channel. The three-dimensional detection envelopes of two types of tags and three types of antennas are quantified as well as the effect of practices (interoperator bias, battery power) on the detection. The interoperator variability and the intertag variability can be considered as negligible. The influence of burial in dry and water-saturated sediment and the influence of water immersion are shown to be minor. Finally, we summarize practical implications for RFID bedload tracking through these experiments.

  18. Investigation of Specific Substitutions in Virulence Genes Characterizing Phenotypic Groups of Low-Virulence Field Strains of Listeria monocytogenes

    PubMed Central

    Roche, S. M.; Gracieux, P.; Milohanic, E.; Albert, I.; Virlogeux-Payant, I.; Témoin, S.; Grépinet, O.; Kerouanton, A.; Jacquet, C.; Cossart, P.; Velge, P.

    2005-01-01

    Several models have shown that virulence varies from one strain of Listeria monocytogenes to another, but little is known about the cause of low virulence. Twenty-six field L. monocytogenes strains were shown to be of low virulence in a plaque-forming assay and in a subcutaneous inoculation test in mice. Using the results of cell infection assays and phospholipase activities, the low-virulence strains were assigned to one of four groups by cluster analysis and then virulence-related genes were sequenced. Group I included 11 strains that did not enter cells and had no phospholipase activity. These strains exhibited a mutated PrfA; eight strains had a single amino acid substitution, PrfAK220T, and the other three had a truncated PrfA, PrfAΔ174-237. These genetic modifications could explain the low virulence of group I strains, since mutated PrfA proteins were inactive. Group II and III strains entered cells but did not form plaques. Group II strains had low phosphatidylcholine phospholipase C activity, whereas group III strains had low phosphatidylinositol phospholipase C activity. Several substitutions were observed for five out of six group III strains in the plcA gene and for one out of three group II strains in the plcB gene. Group IV strains poorly colonized spleens of mice and were practically indistinguishable from fully virulent strains on the basis of the above-mentioned in vitro criteria. These results demonstrate a relationship between the phenotypic classification and the genotypic modifications for at least group I and III strains and suggest a common evolution of these strains within a group. PMID:16204519

  19. Large field-of-view and depth-specific cortical microvascular imaging underlies regional differences in ischemic brain

    NASA Astrophysics Data System (ADS)

    Qin, Jia; Shi, Lei; Dziennis, Suzan; Wang, Ruikang K.

    2014-02-01

    Ability to non-invasively monitor and quantify of blood flow, blood vessel morphology, oxygenation and tissue morphology is important for improved diagnosis, treatment and management of various neurovascular disorders, e.g., stroke. Currently, no imaging technique is available that can satisfactorily extract these parameters from in vivo microcirculatory tissue beds, with large field of view and sufficient resolution at defined depth without any harm to the tissue. In order for more effective therapeutics, we need to determine the area of brain that is damaged but not yet dead after focal ischemia. Here we develop an integrated multi-functional imaging system, in which SDW-LSCI (synchronized dual wavelength laser speckle imaging) is used as a guiding tool for OMAG (optical microangiography) to investigate the fine detail of tissue hemodynamics, such as vessel flow, profile, and flow direction. We determine the utility of the integrated system for serial monitoring afore mentioned parameters in experimental stroke, middle cerebral artery occlusion (MCAO) in mice. For 90 min MCAO, onsite and 24 hours following reperfusion, we use SDW-LSCI to determine distinct flow and oxygenation variations for differentiation of the infarction, peri-infarct, reduced flow and contralateral regions. The blood volumes are quantifiable and distinct in afore mentioned regions. We also demonstrate the behaviors of flow and flow direction in the arterials connected to MCA play important role in the time course of MCAO. These achievements may improve our understanding of vascular involvement under pathologic and physiological conditions, and ultimately facilitate clinical diagnosis, monitoring and therapeutic interventions of neurovascular diseases, such as ischemic stroke.

  20. Investigating temporal field sampling strategies for site-specific calibration of three soil moisture - neutron intensity parameterisation methods

    NASA Astrophysics Data System (ADS)

    Iwema, J.; Rosolem, R.; Baatz, R.; Wagener, T.; Bogena, H. R.

    2015-02-01

    The Cosmic-Ray Neutron Sensor (CRNS) can provide soil moisture information at scales relevant to hydrometeorological modeling applications. Site-specific calibration is needed to translate CRNS neutron intensities into sensor footprint average soil moisture contents. We investigated temporal sampling strategies for calibration of three CRNS parameterisations (modified N0, HMF, and COSMIC) by assessing the effects of the number of sampling days and soil wetness conditions on the performance of the calibration results, for three sites with distinct climate and land use: a semi-arid site, a temperate grassland and a temperate forest. When calibrated with a year of data, COSMIC performed relatively good at all three sites, and the modified N0 method performed best at the two humid sites. It is advisable to collect soil moisture samples on more than a single day regardless of which parameterisation is used. In any case, sampling on more than ten days would, despite the strong increase in work effort, improve calibration results only little. COSMIC needed the least number of days at each site. At the semi-arid site, the N0mod method was calibrated better under average wetness conditions, whereas HMF and COSMIC were calibrated better under drier conditions. Average soil wetness condition gave better calibration results at the two humid sites. The calibration results for the HMF method were better when calibrated with combinations of days with similar soil wetness conditions, opposed to N0mod and COSMIC, which profited from using days with distinct wetness conditions. The outcomes of this study can be used by researchers as a CRNS calibration strategy guideline.

  1. Assessment of Myocardial Remodeling Using an Elastin/Tropoelastin Specific Agent with High Field Magnetic Resonance Imaging (MRI)

    PubMed Central

    Protti, Andrea; Lavin, Begoña; Dong, Xuebin; Lorrio, Silvia; Robinson, Simon; Onthank, David; Shah, Ajay M; Botnar, Rene M

    2015-01-01

    Background Well-defined inflammation, proliferation, and maturation phases orchestrate the remodeling of the injured myocardium after myocardial infarction (MI) by controlling the formation of new extracellular matrix. The extracellular matrix consists mainly of collagen but also fractions of elastin. It is thought that elastin is responsible for maintaining elastic properties of the myocardium, thus reducing the risk of premature rupture. An elastin/tropoelastin–specific contrast agent (Gd-ESMA) was used to image tropoelastin and mature elastin fibers for in vivo assessment of extracellular matrix remodeling post-MI. Methods and Results Gd-ESMA enhancement was studied in a mouse model of myocardial infarction using a 7 T MRI scanner and results were compared to those achieved after injection of a nonspecific control contrast agent, gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA). In the infarcted tissue, Gd-ESMA uptake (measured as R1 relaxation rate) steadily increased from day 3 to day 21 as a result of the synthesis of elastin/tropoelastin. R1 values were in good agreement with histological findings. A similar R1 behavior was observed in the remote myocardium. No mature cross-linked elastin was found at any time point. In contrast, Gd-DTPA uptake was only observed in the infarct with no changes in R1 values between 3 and 21 days post-MI. Conclusions We demonstrate the feasibility of in vivo imaging of extracellular matrix remodeling post-MI using a tropoelastin/elastin binding MR contrast agent, Gd-ESMA. We found that tropoelastin is the main contributor to the increased MRI signal at late stages of MI where its augmentation in areas of infarction was in good agreement with the R1 increase. PMID:26272655

  2. Outdoor measurement of SAR (specific absorption rate) in a full-sized human model exposed to 29. 9 MHz in the near field

    SciTech Connect

    Olsen, R.G.; Griner, T.A.

    1989-01-01

    Localized and averaged specific absorption rates (SARs) were obtained in a full-size muscle-equivalent human model exposed to near-field 29.9-MHz irradiation at an outdoor facility. The model was positioned erect on a metallic groundplane 1.22 m (4 ft) from the base of a 10.8-m (35 ft) whip antenna with an input power of 1.0 kW. For whole-body SAR, a mean value of 0.83 W/kg was determined using two gradient-layer calorimeters in a twin-well configuration. The localized SARs at 12 body locations were measured using nonperturbing temperature probes and were highest in the ankle region. It is concluded that average SAR measurements in a full-size phantom are feasible using a twin-calorimeter approach; measurements in the field are practical when human-size (183 x 61 x 46 cm) calorimeters are used.

  3. Highly specific and sensitive non-enzymatic determination of uric acid in serum and urine by extended gate field effect transistor sensors.

    PubMed

    Guan, Weihua; Duan, Xuexin; Reed, Mark A

    2014-01-15

    A potentiometric non-enzymatic sensor using off-chip extended-gate field effect transistor (EGFET) with a ferrocenyl-alkanethiol modified gold electrode is demonstrated for determining the uric acid concentration in human serum and urine. Hexacyanoferrate (II) and (III) ions are used as redox reagent. This potentiometric sensor measures the interface potential on the ferrocene immobilized gold electrode, which is modulated by the redox reaction between uric acid and hexacyanoferrate ions. The device shows a near Nernstian response to uric acid and is highly specific. The interference that comes from glucose, bilirubin, ascorbic acid and hemoglobin is negligible in normal concentration range of these interferents. The sensor also exhibits excellent long term reliability. This extended gate field effect transistor based sensors can be used as a point of care UA testing tool, due to the small size, low cost, and low sample volume consumption. PMID:23968728

  4. Communication: An efficient approach to compute state-specific nuclear gradients for a generic state-averaged multi-configuration self consistent field wavefunction

    NASA Astrophysics Data System (ADS)

    Granovsky, Alexander A.

    2015-12-01

    We present a new, very efficient semi-numerical approach for the computation of state-specific nuclear gradients of a generic state-averaged multi-configuration self consistent field wavefunction. Our approach eliminates the costly coupled-perturbed multi-configuration Hartree-Fock step as well as the associated integral transformation stage. The details of the implementation within the Firefly quantum chemistry package are discussed and several sample applications are given. The new approach is routinely applicable to geometry optimization of molecular systems with 1000+ basis functions using a standalone multi-core workstation.

  5. Specific Heat vs Field in the 30 K Superconductor BaFe2(As0.7P0.3)2

    NASA Astrophysics Data System (ADS)

    Stewart, G. R.; Kim, J. S.; Hirschfeld, P. J.; Kasahara, S.; Shibauchi, T.; Terashima, T.; Matsuda, Y.

    2010-03-01

    Recently, superconductivity at 30 K has been reported [1] in P-doped BaFe2As2, with 1/3 of the As replaced by P. Magnetic penetration and thermal conductivity measurements [2] indicate a nodally gapped superconductor. We report here on measurements of the specific heat divided by temperature, C/T, as a function of field up to 15 T and down to 0.4 K in order to further investigate the nodal structure with another probe. [4pt] [1] S. Kasahara, et al., arXiv0905.4427. [0pt] [2] K. Hashimoto, et al., arXiv0907.4399.

  6. Communication: An efficient approach to compute state-specific nuclear gradients for a generic state-averaged multi-configuration self consistent field wavefunction

    SciTech Connect

    Granovsky, Alexander A.

    2015-12-21

    We present a new, very efficient semi-numerical approach for the computation of state-specific nuclear gradients of a generic state-averaged multi-configuration self consistent field wavefunction. Our approach eliminates the costly coupled-perturbed multi-configuration Hartree-Fock step as well as the associated integral transformation stage. The details of the implementation within the Firefly quantum chemistry package are discussed and several sample applications are given. The new approach is routinely applicable to geometry optimization of molecular systems with 1000+ basis functions using a standalone multi-core workstation.

  7. Evidence for Chiral d-Wave Superconductivity in URu2Si2 from the Field-Angle Variation of Its Specific Heat

    NASA Astrophysics Data System (ADS)

    Kittaka, Shunichiro; Shimizu, Yusei; Sakakibara, Toshiro; Haga, Yoshinori; Yamamoto, Etsuji; Ōnuki, Yoshichika; Tsutsumi, Yasumasa; Nomoto, Takuya; Ikeda, Hiroaki; Machida, Kazushige

    2016-03-01

    Low-energy quasiparticle (QP) excitations in the heavy-fermion superconductor URu2Si2 were investigated by specific-heat C(T,H,φ ,θ ) measurements of a high-quality single crystal. The occurrence of QP excitations due to the Doppler-shift effect was detected regardless of the field direction in C(H) of the present clean sample, which is in sharp contrast to a previous report. Furthermore, the polar-angle-dependent C(θ) measured under a rotating magnetic field within the ac plane exhibits a shoulder-like anomaly at θ ˜ 45° and a sharp dip at θ = 90° (H || a) in the moderate-field region. These features are supported by theoretical analyses based on microscopic calculations assuming the gap symmetry of kz(kx + iky), whose gap structure is characterized by a combination of a horizontal line node at the equator and point nodes at the poles. The present results have settled the previous controversy over the gap structure of URu2Si2 and have authenticated its chiral d-wave superconductivity.

  8. Abstract: Magnetic solitons' contribution to the specific heat of (CH3)4NMnCl3 in an external magnetic field

    NASA Astrophysics Data System (ADS)

    Borsa, F.

    1982-03-01

    It has been shown theoretically that linear magnetic systems with planar anisotropy should display nonlinear excitations, i.e., sine-Gordon solitons upon application of a magnetic field perpendicular to the chain axis. Experimental evidence for ID magnetic solitons has been presented for TMMC from neutron scattering and NMR measurements.1 The classical statistical mechanics of this system predict a soliton contribution to the free energy and thus to the specific heat.2 In order to test experimentally the thermodynamic relevance of magnetic solitons, I performed measurements of specific heat in single crystal TMMC in an external magnetic field up to 10 Tesla, applied both perpendicular and parallel to the chain. The measurements were performed with an adiabatic calorimeter in the temperature range 1.5-15 °K. The results show an extra contribution for H⊥c not present for H∥c. This contribution displays a broad maximum which scales approximately as H/T in agreement with the theory. The maximum occurs just above the peak in the specific heat which is observed in correspondence to the three-dimensional transition temperature, and it can be clearly resolved only for H⩾5.0 T. The soliton energy obtained by fitting the experiments to the classical theory is Es = 2.0 H for H = 5.39 T and Es = 1.8 H for H = 10 T to be compared with the theoretical value of Es = gμBHS = 3.35 H and with the value obtained by neutron scattering at H = 3.2 T, i.e., Es = 2.6 H. The discrepancy between theory and experiment is discussed in terms of renormalization corrections and of a possible soliton instability occurring for fields between 3 and 5 T. a)Permanent address: Institut di Fisica, Universita di Pavia, 27100 Pavia, Italy. 1J. P. Boucher, L. P. Regnault, J. Rossad Miguod, J. P. Renard, J. Bouillot, and W. G. Stirling, J. Appl. Phys. 52, 1956 (1981). 2K. M. Leung, D. Hone, D. L. Mills, P. S. Riseborough, and S. E. Trullinger, Phys. Rev. B 21, 4017 (1980).

  9. Characterization of BoHV-5 field strains circulation and report of transient specific subtype of bovine herpesvirus 5 in Argentina

    PubMed Central

    2011-01-01

    Background Bovine herpesvirus 5 (BoHV-5) is a member of the subfamily Alphaherpesvirinae responsible for meningo-encephalitis in young cattle. The first case of bovine meningo-encephalitis associated with a herpesvirus infection was reported in Australia. The current geographical distribution of BoHV-5 infection is mainly restricted to South America, especially Brazil and Argentina. Outbreaks of BoHV-5 are regularly observed in Argentina suggesting the circulation of the virus in the bovine population. Results Seventeen field strains of BoHV-5 isolated from 1984 to now were confirmed by differential PCR and subjected to restriction endonuclease analysis (REA). Viral DNA was cleaved with BstEII which allows the differentiation among subtypes a, b and non a, non b. According to the REA with BstEII, only one field strain showed a pattern similar to the Argentinean A663 strain (prototype of BoHV-5b). All other isolates showed a clear pattern similar to the Australian N569 strain (prototype of BoHV-5a) consistent with the subtypes observed in Brazil, the other South-American country where BoHV-5 is known to be prevalent. The genomic region of subtype b responsible for the distinct pattern was determined and amplified by PCR; specifically a point mutation was identified in glycoprotein B gene, on the BstEII restriction site, which generates the profile specific of BoHV-5b. Conclusions This is the first report of circulation of BoHV-5a in Argentina as the prevailing subtype. Therefore the circulation of BoHV-5b was restricted to a few years in Argentina, speculating that this subtype was not able to be maintained in the bovine population. The mutation in the gB gene is associated with the difference in the restriction patterns between subtypes "a" and "b". PMID:21299866

  10. Breast-specific gamma-imaging: molecular imaging of the breast using 99mTc-sestamibi and a small-field-of-view gamma-camera.

    PubMed

    Jones, Elizabeth A; Phan, Trinh D; Blanchard, Deborah A; Miley, Abbe

    2009-12-01

    Breast-specific gamma-imaging (BSGI), also known as molecular breast imaging, is breast scintigraphy using a small-field-of-view gamma-camera and (99m)Tc-sestamibi. There are many different types of breast cancer, and many have characteristics making them challenging to detect by mammography and ultrasound. BSGI is a cost-effective, highly sensitive and specific technique that complements other imaging modalities currently being used to identify malignant lesions in the breast. Using the current Society of Nuclear Medicine guidelines for breast scintigraphy, Legacy Good Samaritan Hospital began conducting BSGI, breast scintigraphy with a breast-optimized gamma-camera. In our experience, optimal imaging has been conducted in the Breast Center by a nuclear medicine technologist. In addition, the breast radiologists read the BSGI images in correlation with the mammograms, ultrasounds, and other imaging studies performed. By modifying the current Society of Nuclear Medicine protocol to adapt it to the practice of breast scintigraphy with these new systems and by providing image interpretation in conjunction with the other breast imaging studies, our center has found BSGI to be a valuable adjunctive procedure in the diagnosis of breast cancer. The development of a small-field-of-view gamma-camera, designed to optimize breast imaging, has resulted in improved detection capabilities, particularly for lesions less than 1 cm. Our experience with this procedure has proven to aid in the clinical work-up of many of our breast patients. After reading this article, the reader should understand the history of breast scintigraphy, the pharmaceutical used, patient preparation and positioning, imaging protocol guidelines, clinical indications, and the role of breast scintigraphy in breast cancer diagnosis. PMID:19914975

  11. How accurately can subject-specific finite element models predict strains and strength of human femora? Investigation using full-field measurements.

    PubMed

    Grassi, Lorenzo; Väänänen, Sami P; Ristinmaa, Matti; Jurvelin, Jukka S; Isaksson, Hanna

    2016-03-21

    Subject-specific finite element models have been proposed as a tool to improve fracture risk assessment in individuals. A thorough laboratory validation against experimental data is required before introducing such models in clinical practice. Results from digital image correlation can provide full-field strain distribution over the specimen surface during in vitro test, instead of at a few pre-defined locations as with strain gauges. The aim of this study was to validate finite element models of human femora against experimental data from three cadaver femora, both in terms of femoral strength and of the full-field strain distribution collected with digital image correlation. The results showed a high accuracy between predicted and measured principal strains (R(2)=0.93, RMSE=10%, 1600 validated data points per specimen). Femoral strength was predicted using a rate dependent material model with specific strain limit values for yield and failure. This provided an accurate prediction (<2% error) for two out of three specimens. In the third specimen, an accidental change in the boundary conditions occurred during the experiment, which compromised the femoral strength validation. The achieved strain accuracy was comparable to that obtained in state-of-the-art studies which validated their prediction accuracy against 10-16 strain gauge measurements. Fracture force was accurately predicted, with the predicted failure location being very close to the experimental fracture rim. Despite the low sample size and the single loading condition tested, the present combined numerical-experimental method showed that finite element models can predict femoral strength by providing a thorough description of the local bone mechanical response. PMID:26944687

  12. Confirmation of the assignment of the low-field proton resonance of serine proteases by using specifically nitrogen-15 labeled enzyme.

    PubMed

    Bachovchin, W W

    1985-12-01

    Proton NMR spectra of serine proteases in 1H2O solutions typically show a single resonance at very low magnetic field--i.e., 14-18 ppm from dimethylsilylapentanesulfonate. This resonance has been assigned to the proton hydrogen bonded between aspartic acid-102 and histidine-57 (chymotrypsin numbering system) of the "charge-relay system" or catalytic triad of serine proteases [Robillard, G. & Shulman, R. G. (1972) J. Mol. Biol. 71, 507-511]. Since then, there have been a number of reports that have cast doubt on its correctness. In the present work we have tested this assignment using alpha-lytic protease (EC 3.4.21.12, Myxobacter alpha-lytic proteinase), a bacterial serine protease homologous to elastase, which is specifically labeled with nitrogen-15 at N delta 1 of its single histidine residue. The low-field region of the proton spectra of this labeled enzyme shows a single resonance having the properties reported [Robillard, G. & Shulman, R. G. (1974) J. Mol. Biol. 86, 519-540], which, in addition, exhibits spin-spin splitting to the nitrogen-15 label. The observation of this 15N delta 1-H coupling makes the assignment of this resonance to the charge-relay proton unequivocal. PMID:3934665

  13. Confirmation of the assignment of the low-field proton resonance of serine proteases by using specifically nitrogen-15 labeled enzyme

    SciTech Connect

    Bachovchin, W.W.

    1985-12-01

    Proton NMR spectra of serine proteases in /sup 1/H/sub 2/O solutions typically show a single resonance at very low magnetic field i.e., 14-18 ppm from dimethylsilylapentanesulfonate. This resonance has been assigned to the proton hydrogen bonded between aspartic acid-102 and histidine-57 (chymotrypsin numbering system) of the charge-relay system or catalytic triad of serine proteases. There have been a number of reports that have cast doubt on its correctness. In the present work the authors have tested this assignment using ..cap alpha..-lytic protease, a bacterial serine protease homologous to elastase, which is specifically labeled with nitrogen-15 at N/sup delta/sub 1// of its single histidine residue. The low-field region of the proton spectra of this labeled enzyme shows a single resonance having the properties reported which, in addition, exhibits spin-spin splitting to the nitrogen-15 label. The observation of this /sup 15/N-/sup delta/sub 1//-H coupling makes the assignment of this resonance to the charge-relay proton unequivocal.

  14. Specific absorption rate and temperature elevation in a subject exposed in the far-field of radio-frequency sources operating in the 10-900-MHz range.

    PubMed

    Bernardi, Paolo; Cavagnaro, Marta; Pisa, Stefano; Piuzzi, Emanuele

    2003-03-01

    The exposure of a subject in the far field of radiofrequency sources operating in the 10-900-MHz range has been studied. The electromagnetic field inside an anatomical heterogeneous model of the human body has been computed by using the finite-difference time-domain method; the corresponding temperature increase has been evaluated through an explicit finite-difference formulation of the bio-heat equation. The thermal model used, which takes into account the thermoregulatory system of the human body, has been validated through a comparison with experimental data. The results show that the peak specific absorption rate (SAR) as averaged over 10 g has about a 25-fold increase in the trunk and a 50-fold increase in the limbs with respect to the whole body averaged SAR (SARWB). The peak SAR as averaged over 1 g, instead, has a 30- to 60-fold increase in the trunk, and up to 135-fold increase in the ankles, with respect to SARWB. With reference to temperature increases, at the body resonance frequency of 40 MHz, for the ICNIRP incident power density maximum permissible value, a temperature increase of about 0.7 degrees C is obtained in the ankles muscle. The presence of the thermoregulatory system strongly limits temperature elevations, particularly in the body core. PMID:12669986

  15. Open-field host specificity test of Gratiana boliviana (Coleoptera: Chrysomelidae), a biological control agent of tropical soda apple (Solanaceae) in the United States

    SciTech Connect

    Gandolfo, D.; McKay, F.; Medal, J.C.; Cuda, J.P.

    2007-03-15

    An open-field experiment was conducted to assess the suitability of the South American leaf feeding beetle Gratiana boliviana Spaeth for biological control of Solanum viarum Dunal in the USA. An open-field test with eggplant, Solanum melongena L., was conducted on the campus of the University of Buenos Aires, Argentina, and a S. viarum control plot was established 40 km from the campus. One hundred adult beetles were released in each plot at the beginning of the experiment during the vegetative stage of the plants, and forty additional beetles were released in the S. melongena plot at the flowering stage. All the plants in each plot were checked twice a week and the number of adults, immatures, and eggs recorded. Results showed almost a complete rejection of eggplant by G. boliviana. No noticeable feeding damage was ever recorded on eggplant. The experiment was ended when the eggplants started to senesce or were severely damaged by whiteflies and spider mites. The results of this open-field experiment corroborate previous quarantine/laboratory host-specificity tests indicating that a host range expansion of G. boliviana to include eggplant is highly unlikely. Gratiana boliviana was approved for field release in May 2003 in the USA. To date, no non-target effects have been observed either on eggplant or native species of Solanum. (author) [Spanish] Una prueba de campo fue conducida para evaluar la especificidad del escarabajo suramericano defoliador Gratiana boliviana Spaeth para control biologico de Solanum viarum Dunal en los Estados Unidos. La prueba con berenjena se realizo en el campo experimental de la Universidad de Buenos Aires, Argentina, y una parcela control con S. viarum fue establecida a 40 km. Cien escarabajos adultos fueron liberados en cada parcela al inicio del experimento durante la fase vegetativa, y cuarenta escarabajos adicionales fueron liberados en la parcela de berenjena durante la floracion. Todas las plantas en cada parcela fueron

  16. Measurements of ankle specific absorption rate and body-to-ground current in a suit-protected human model for near-field exposures, 2-400 MHz

    SciTech Connect

    Olsen, R.G.; Van Matre, B.J.

    1994-06-01

    The potential usefulness of a protective-suit ensemble to reduce specific absorption rate (SAR) at submicrowave frequencies was studied using a full-sized, muscle-equivalent human model. In the past, such suits were used predominantly for microwave protection, but some highly conductive suits presented a very real fire hazard when arcing was considered. Suits made from partially conductive fabric were slightly less effective against microwaves but were much less flammable; moreover, their performance against other radiofrequencies (RFs) has not been studied. Recently promulgated exposure standards have imposed theoretical maximum body-currents to limit extremity SAR to 20 W/kg and have impacted certain occupational environments such as those surrounding RF transmitting towers and RF heat sealers. In the present research, reactive near-field irradiation conditions were used at 2.025 and 29.9 MHz, and quasi-near-field conditions were used at 80.0 and 400.0 MHz. Nonperturbing thermal probes were used to measure RF-induced temperature rises from which localized ankle SARs were calculated; a stand-on RF milliammeter recorded RF body-to-ground current over metallic groundplanes. Mean ankle SARs of greater than 23 W/kg were measured for some unprotected conditions, but with full ensemble protection (suit, hood, and overshoes) no mean ankle SAR exceeded 1.1 W/kg. The suit without the overshoes, however, did not reduce ankle SAR. At 29.9 and 80.0 MHz, the presence or absence of the hood caused relatively small SAR changes. We attribute the suit`s ability in reducing ankle SAR to the partially conducting nature of the metal/textile material and to the ability of the overshoes to shunt RF current around the ankles. We recommend that further use of partially conducting fabrics be explored to provide practical means of reducing occupational RF-induced extremity SAR to acceptable levels. 16 refs., 2 figs., 1 tab.

  17. Inhibition of Cancer Cell Growth by Exposure to a Specific Time-Varying Electromagnetic Field Involves T-Type Calcium Channels

    PubMed Central

    Buckner, Carly A.; Buckner, Alison L.; Koren, Stan A.; Persinger, Michael A.; Lafrenie, Robert M.

    2015-01-01

    Electromagnetic field (EMF) exposures affect many biological systems. The reproducibility of these effects is related to the intensity, duration, frequency, and pattern of the EMF. We have shown that exposure to a specific time-varying EMF can inhibit the growth of malignant cells. Thomas-EMF is a low-intensity, frequency-modulated (25-6 Hz) EMF pattern. Daily, 1 h, exposures to Thomas-EMF inhibited the growth of malignant cell lines including B16-BL6, MDA-MB-231, MCF-7, and HeLa cells but did not affect the growth of non-malignant cells. Thomas-EMF also inhibited B16-BL6 cell proliferation in vivo. B16-BL6 cells implanted in syngeneic C57b mice and exposed daily to Thomas-EMF produced smaller tumours than in sham-treated controls. In vitro studies showed that exposure of malignant cells to Thomas-EMF for > 15 min promoted Ca2+ influx which could be blocked by inhibitors of voltage-gated T-type Ca2+ channels. Blocking Ca2+ uptake also blocked Thomas-EMF-dependent inhibition of cell proliferation. Exposure to Thomas-EMF delayed cell cycle progression and altered cyclin expression consistent with the decrease in cell proliferation. Non-malignant cells did not show any EMF-dependent changes in Ca2+ influx or cell growth. These data confirm that exposure to a specific EMF pattern can affect cellular processes and that exposure to Thomas-EMF may provide a potential anti-cancer therapy. PMID:25875081

  18. THE SPECTRAL ENERGY DISTRIBUTIONS OF z ∼ 8 GALAXIES FROM THE IRAC ULTRA DEEP FIELDS: EMISSION LINES, STELLAR MASSES, AND SPECIFIC STAR FORMATION RATES AT 650 MYR

    SciTech Connect

    Labbé, I.; Bouwens, R. J.; Franx, M.; Oesch, P. A.; Illingworth, G. D.; Magee, D.; González, V.; Trenti, M.; Van Dokkum, P. G.; Stiavelli, M.

    2013-11-10

    Using new ultradeep Spitzer/InfraRed Array Camera (IRAC) photometry from the IRAC Ultra Deep Field program, we investigate the stellar populations of a sample of 63 Y-dropout galaxy candidates at z ∼ 8, only 650 Myr after the big bang. The sources are selected from HST/ACS+WFC3/IR data over the Hubble Ultra Deep Field (HUDF), two HUDF parallel fields, and wide area data over the CANDELS/GOODS-South. The new Spitzer/IRAC data increase the coverage in [3.6] and [4.5] to ∼120h over the HUDF reaching depths of ∼28 (AB,1σ). The improved depth and inclusion of brighter candidates result in direct ≥3σ InfraRed Array Camera (IRAC) detections of 20/63 sources, of which 11/63 are detected at ≥5σ. The average [3.6]-[4.5] colors of IRAC detected galaxies at z ∼ 8 are markedly redder than those at z ∼ 7, observed only 130 Myr later. The simplest explanation is that we witness strong rest-frame optical emission lines (in particular [O III] λλ4959, 5007 + Hβ) moving through the IRAC bandpasses with redshift. Assuming that the average rest-frame spectrum is the same at both z ∼ 7 and z ∼ 8 we estimate a rest-frame equivalent width of contributing 0.56{sup +0.16}{sub -0.11} mag to the [4.5] filter at z ∼ 8. The corresponding W{sub Hα}=430{sup +160}{sub -110} Å implies an average specific star formation rate of sSFR=11{sub -5}{sup +11} Gyr{sup –1} and a stellar population age of 100{sub -50}{sup +100} Myr. Correcting the spectral energy distribution for the contribution of emission lines lowers the average best-fit stellar masses and mass-to-light ratios by ∼3 ×, decreasing the integrated stellar mass density to ρ{sup *}(z=8,M{sub UV}<-18)=0.6{sup +0.4}{sub -0.3}×10{sup 6} M{sub sun} Mpc{sup –3}.

  19. Assessing microbial degradation of o-xylene at field-scale from the reduction in mass flow rate combined with compound-specific isotope analyses.

    PubMed

    Peter, A; Steinbach, A; Liedl, R; Ptak, T; Michaelis, W; Teutsch, G

    2004-07-01

    In recent years, natural attenuation (NA) has evolved into a possible remediation alternative, especially in the case of BTEX spills. In order to be approved by the regulators, biodegradation needs to be demonstrated which requires efficient site investigation and monitoring tools. Three methods--the Integral Groundwater Investigation method, the compound-specific isotope analysis (CSIA) and a newly developed combination of both--were used in this work to quantify at field scale the biodegradation of o-xylene at a former gasworks site which is heavily contaminated with BTEX and PAHs. First, the Integral Groundwater Investigation method [Schwarz, R., Ptak, T., Holder, T., Teutsch, G., 1998. Groundwater risk assessment at contaminated sites: a new investigation approach. In: Herbert, M. and Kovar, K. (Editors), GQ'98 Groundwater Quality: Remediation and Protection. IAHS Publication 250, pp. 68-71; COH 4 (2000) 170] was applied, which allows the determination of mass flow rates of o-xylene by integral pumping tests. Concentration time series obtained during pumping at two wells were used to calculate inversely contaminant mass flow rates at the two control planes that are defined by the diameter of the maximum isochrone. A reactive transport model was used within a Monte Carlo approach to identify biodegradation as the dominant process for reduction in the contaminant mass flow rate between the two consecutive control planes. Secondly, compound-specific carbon isotope analyses of o-xylene were performed on the basis of point-scale samples from the same two wells. The Rayleigh equation was used to quantify the degree of biodegradation that occurred between the wells. Thirdly, a combination of the Integral Groundwater Investigation method and the compound-specific isotope analysis was developed and applied. It comprises isotope measurements during the integral pumping tests and the evaluation of delta13C time series by an inversion algorithm to obtain spatially

  20. Assessing microbial degradation of o-xylene at field-scale from the reduction in mass flow rate combined with compound-specific isotope analyses

    NASA Astrophysics Data System (ADS)

    Peter, A.; Steinbach, A.; Liedl, R.; Ptak, T.; Michaelis, W.; Teutsch, G.

    2004-07-01

    In recent years, natural attenuation (NA) has evolved into a possible remediation alternative, especially in the case of BTEX spills. In order to be approved by the regulators, biodegradation needs to be demonstrated which requires efficient site investigation and monitoring tools. Three methods—the Integral Groundwater Investigation method, the compound-specific isotope analysis (CSIA) and a newly developed combination of both—were used in this work to quantify at field scale the biodegradation of o-xylene at a former gasworks site which is heavily contaminated with BTEX and PAHs. First, the Integral Groundwater Investigation method [Schwarz, R., Ptak, T., Holder, T., Teutsch, G., 1998. Groundwater risk assessment at contaminated sites: a new investigation approach. In: Herbert, M. and Kovar, K. (Editors), GQ'98 Groundwater Quality: Remediation and Protection. IAHS Publication 250, pp. 68-71; COH 4 (2000) 170] was applied, which allows the determination of mass flow rates of o-xylene by integral pumping tests. Concentration time series obtained during pumping at two wells were used to calculate inversely contaminant mass flow rates at the two control planes that are defined by the diameter of the maximum isochrone. A reactive transport model was used within a Monte Carlo approach to identify biodegradation as the dominant process for reduction in the contaminant mass flow rate between the two consecutive control planes. Secondly, compound-specific carbon isotope analyses of o-xylene were performed on the basis of point-scale samples from the same two wells. The Rayleigh equation was used to quantify the degree of biodegradation that occurred between the wells. Thirdly, a combination of the Integral Groundwater Investigation method and the compound-specific isotope analysis was developed and applied. It comprises isotope measurements during the integral pumping tests and the evaluation of δ13C time series by an inversion algorithm to obtain spatially

  1. A new species of Demodex (Acari: Demodecidae) with data on topical specificity and topography of demodectic mites in the striped field mouse Apodemus agrarius (Rodentia: Muridae).

    PubMed

    Izdebska, Joanna N; Rolbiecki, Leszek

    2013-11-01

    This article describes morphological characteristics and the occurrence of Demodex gracilentus sp. nov., which was found in the striped field mouse Apodemus agrarius (Pallas, 1771) in the skin of vibrissae area. D. gracilentus occurred in 36.7% of the rodents examined. D. gracilentus is a relatively large representative of the genus (adult stages on average 292 microm in length), a slender, elongated body; characteristic feature of these mites are conical supracoxal spines on dorsal side of gnathosoma, palps with asymmetric, forked triple spines on palptarsus, and the presence of rhomboidal opisthosomal organ. So far, the occurrence of three specific representatives of the family Demodecidae has been demonstrated in A. agrarius: Demodex apodemi (Hirst, 1918) (= Demodex arvicolae apodemi Hirst, 1918), Demodex agrarii Bukva, 1994, and Demodex huttereri Mertens, Lukoschus et Nutting, 1983. The first one is related to common hair follicles, especially in the skin of the head, while the next one inhabits the external auditory meatus, and the last one occurs in the meibomian glands of the eyelids. PMID:24843923

  2. Columnar specificity of microvascular oxygenation and blood flow response in primary visual cortex: evaluation by local field potential and spiking activity.

    PubMed

    Wang, Zheng; Roe, Anna W

    2012-01-01

    The relation of cortical microcirculation, oxygen metabolism, and underlying neuronal network activity remains poorly understood. Anatomical distribution of cortical microvasculature and its relationship to cortical functional domains suggests that functional organizations may be revealed by mapping cerebral blood flow responses. However, there is little direct experimental evidence and a lack of electrophysiological evaluation. In this study, we mapped ocular-dominance columns in primary visual cortex (V1) of anesthetized macaques with capillary flow-based laser speckle contrast imaging and deoxyhemoglobin-based intrinsic optical imaging. In parallel, the local field potentials (LFPs) and spikes were recorded from a linear array of eight microelectrodes, carefully positioned into left and right eye columns in V1. We found differential activation maps of blood flow, after masking large superficial draining vessels, exhibited a column-like pattern similar as the oximetric maps. Both the activated spikes and γ-band LFP demonstrated corresponding eye preference, consistent with the imaging maps. Our results present direct support in favor of previous proposals that the regulation of microcirculation can be as fine as the submillimeter scale, suggesting that cortical vasculature is functionally organized at the columnar level in a manner appropriate for supplying energy demands of functionally specific neuronal populations. PMID:22027939

  3. Ultra-low specific on-resistance high-voltage vertical double diffusion metal–oxide–semiconductor field-effect transistor with continuous electron accumulation layer

    NASA Astrophysics Data System (ADS)

    Da, Ma; Xiao-Rong, Luo; Jie, Wei; Qiao, Tan; Kun, Zhou; Jun-Feng, Wu

    2016-04-01

    A new ultra-low specific on-resistance (R on,sp) vertical double diffusion metal–oxide–semiconductor field-effect transistor (VDMOS) with continuous electron accumulation (CEA) layer, denoted as CEA-VDMOS, is proposed and its new current transport mechanism is investigated. It features a trench gate directly extended to the drain, which includes two PN junctions. In on-state, the electron accumulation layers are formed along the sides of the extended gate and introduce two continuous low-resistance current paths from the source to the drain in a cell pitch. This mechanism not only dramatically reduces the R on,sp but also makes the R on,sp almost independent of the n-pillar doping concentration (N n). In off-state, the depletion between the n-pillar and p-pillar within the extended trench gate increases the N n, and further reduces the R on,sp. Especially, the two PN junctions within the trench gate support a high gate–drain voltage in the off-state and on-state, respectively. However, the extended gate increases the gate capacitance and thus weakens the dynamic performance to some extent. Therefore, the CEA-VDMOS is more suitable for low and medium frequencies application. Simulation indicates that the CEA-VDMOS reduces the R on,sp by 80% compared with the conventional super-junction VDMOS (CSJ-VDMOS) at the same high breakdown voltage (BV). Project supported by the National Natural Science Foundation of China (Grant Nos. 61176069 and 61376079) and the Fundamental Research Funds for the Central Universities, China (Grant No. ZYGX2014Z006).

  4. Si-N membrane microcalorimetry: Thermal conductivity and specific heat of thin films from 2-500K in magnetic fields to 8 Tesla.

    NASA Astrophysics Data System (ADS)

    Zink, Barry

    2003-03-01

    Understanding the thermal behavior of mesoscopic systems and thin films is a critical issue of both fundamental and technological solid state science. Despite the wealth of knowledge in principle available from accurate measurement of specific heat and thermal conductivity of thin films, there are relatively few results of this type, due to the difficulty of isolating the small heat capacities and thermal conductivities from the typically large background contribution of conventional apparatus. Our group at UC San Diego uses amorphous Si-N membranes to thermally isolate small samples from their environment and allow accurate thermal measurements. Recent work adds the ability to measure thermal conductivity of films as thin as 150 Angstrom over a broad temperature range [1] to our well-established techniques for measuring Cp of small samples.[2] Our microcalorimeter is also particularly well-suited for measurements of both Cp and k in high magnetic fields [3]. The micromachining techniques used to fabricate the calorimeter allow production of significant numbers of calorimeters with well-controlled dimensions and highly reproducible properties which facilitates studies of the thermal properties of thin film and tiny crystals. In this talk I will briefly review the fabrication of our microcalorimeter and the techniques for measuring Cp and k. I will present example data and results of numerical heat flow simulations used to further our understanding of heat flow in the microcalorimeter [1] B. L. Zink, B. Revaz, J. J. Cherry and F. Hellman, Submitted to RSI, Sept. 2002 [2] D. W. Denlinger et al., Rev. Sci. Inst 65, 946-59 (1994) [3] B. L. Zink, B. Revaz, R. Sappey and F. Hellman, Rev. Sci. Instrum. 73, 1841 (2002)

  5. Therapy of infections in mice irradiated in mixed neutron/photon fields and inflicted with wound trauma: A review of current work. (Reannouncement with new availability information)

    SciTech Connect

    Ledney, G.D.; Madonna, G.S.; Elliott, T.B.; Moore, M.M.; Jackson, W.E.

    1991-12-31

    When host antimicrobial defenses are severely compromised by radiation or trauma in conjunction with radiation, death from sepsis results. To evaluate therapies for sepsis in radiation casualties, the authors developed models of acquired and induced bacterial infections in irradiated and irradiated-wounded mice. Animals were exposed to either a mixed radiation field of equal proportions of neutrons and gamma rays (n/gamma = 1) from a TRIGA reactor or pure gamma rays from 60 (Co sources). Skin wounds (15% of total body surface area) were inflicted under methoxyflurane anesthesia 1 h after irradiation. In all mice, wounding after irradiation decreased resistance to infection. Treatments with the immunomodulator synthetic trehalose dicorynomycolate (S-TDCM) before or after mixed neutron-gamma irradiation or gamma irradiation increased survival. Therapy with S-TDCM for mice irradiated with either a mixed field or gamma rays increased resistance to Klebsiella pneumoniae-induced infections.

  6. The Spectral Energy Distributions of z ~ 8 Galaxies from the IRAC Ultra Deep Fields: Emission Lines, Stellar Masses, and Specific Star Formation Rates at 650 Myr

    NASA Astrophysics Data System (ADS)

    Labbé, I.; Oesch, P. A.; Bouwens, R. J.; Illingworth, G. D.; Magee, D.; González, V.; Carollo, C. M.; Franx, M.; Trenti, M.; van Dokkum, P. G.; Stiavelli, M.

    2013-11-01

    Using new ultradeep Spitzer/InfraRed Array Camera (IRAC) photometry from the IRAC Ultra Deep Field program, we investigate the stellar populations of a sample of 63 Y-dropout galaxy candidates at z ~ 8, only 650 Myr after the big bang. The sources are selected from HST/ACS+WFC3/IR data over the Hubble Ultra Deep Field (HUDF), two HUDF parallel fields, and wide area data over the CANDELS/GOODS-South. The new Spitzer/IRAC data increase the coverage in [3.6] and [4.5] to ~120h over the HUDF reaching depths of ~28 (AB,1σ). The improved depth and inclusion of brighter candidates result in direct >=3σ InfraRed Array Camera (IRAC) detections of 20/63 sources, of which 11/63 are detected at >=5σ. The average [3.6]-[4.5] colors of IRAC detected galaxies at z ~ 8 are markedly redder than those at z ~ 7, observed only 130 Myr later. The simplest explanation is that we witness strong rest-frame optical emission lines (in particular [O III] λλ4959, 5007 + Hβ) moving through the IRAC bandpasses with redshift. Assuming that the average rest-frame spectrum is the same at both z ~ 7 and z ~ 8 we estimate a rest-frame equivalent width of {W}_{[O\\,\\scriptsize{III}]\\ \\lambda \\lambda 4959,5007+H\\beta }=670^{+260}_{-170} Å contributing 0.56^{+0.16}_{-0.11} mag to the [4.5] filter at z ~ 8. The corresponding {W}_{H\\alpha }=430^{+160}_{-110} Å implies an average specific star formation rate of sSFR=11_{-5}^{+11} Gyr-1 and a stellar population age of 100_{-50}^{+100} Myr. Correcting the spectral energy distribution for the contribution of emission lines lowers the average best-fit stellar masses and mass-to-light ratios by ~3 ×, decreasing the integrated stellar mass density to \\rho ^*(z=8,M_{\\rm{UV}}<-18)=0.6^{+0.4}_{-0.3}\\times 10^6 \\,M_\\odot Mpc-3. Based on observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated

  7. Neutron/gamma dose characterization for use with TLD

    SciTech Connect

    Kee, J.C.; Magee, L.; Hefley, T.

    1991-01-01

    The work described in this paper was performed in preparation for establishing a thermoluminescent dosimetry (TLD) system for workers exposed to spontaneous fission neutrons from mixed plutonium isotopes, {sup 232}Th, and depleted uranium at the US Department of Energy (DOE) Pantex facility. The method proposed uses a neutron-insensitive thermoluminescent dosimeter to measure the gamma dose and apply a neutron dose/gamma dose ratio to calculate the neutron dose equivalent. This approach, while requiring multibadge dosimetry for each individual, provides a more accurate neutron dose calculation than was previously in use and reduces the maximum missed dose and falsely reported dose.

  8. Mu2e Neutron/Gamma Background Analysis

    NASA Astrophysics Data System (ADS)

    Rosendahl, Morgan; Ahmed, Mohamed; Alexander, Damien; Daniel, Aji; Hungerford, Ed; Sikora, Mark; Alcap Collaboration

    2015-10-01

    In Mu2e, a muon-to-electron conversion experiment that will search for neutrinoless lepton conversion with a single event sensitivity of 10-16, a large flux of neutrons with energies less than 10 MeV are emitted after muon capture in the stopping target. These neutrons, and gamma radiation resulting from their absorption, comprise a major component of experimental backgrounds. However, they are not currently sufficiently understood to reliably mitigate single-event-upsets in the readout electronics and time-to-failure of the detector components. At the Paul Scherrer Institute, PSI, a program was undertaken to measure neutron and charged particle emission after muon capture in targets of interest. Two BC501A neutron counters, a Ge, and a LaBr3 detector were used to measure the rates and spectra of emitted neutrons, X-rays, and gammas. The ongoing analysis of this data will provide characterization of the neutron and gamma spectra at low energies. Because the lifetime of a captured muon is nearly a microsecond, the neutron energy spectrum must be determined by unfolding methods. This presentation will discuss the experiment, neutron detector calibrations, and the progress of the analysis.

  9. Open-field host specificity test of Gratiana boliviana (Coleoptera:Chrysomelidae), a biological control agent of Tropical Soda Apple (Solanaceae) in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An open-field experiment was conducted to asses the suitability of the South American leaf feeding beetle Gratiana boliviana Spaeth for biological control of Solanum viarum Dunal in the USA. An open-field test with eggplant, Solanum melongena L., was conducted on the campus of the University of Buen...

  10. Neutron Reference Benchmark Field Specification: ACRR 44 Inch Lead-Boron (LB44) Bucket Environment (ACRR-LB44-CC-32-CL).

    SciTech Connect

    Vega, Richard Manuel; Parma, Edward J.; Griffin, Patrick J.; Vehar, David W.

    2015-07-01

    This report was put together to support the International Atomic Energy Agency (IAEA) REAL- 2016 activity to validate the dosimetry community’s ability to use a consistent set of activation data and to derive consistent spectral characterizations. The report captures details of integral measurements taken in the Annular Core Research Reactor (ACRR) central cavity with the 44 inch Lead-Boron (LB44) bucket, reference neutron benchmark field. The field is described and an “a priori” calculated neutron spectrum is reported, based on MCNP6 calculations, and a subject matter expert (SME) based covariance matrix is given for this “a priori” spectrum. The results of 31 integral dosimetry measurements in the neutron field are reported.

  11. FIELD CHECK MANUAL FOR LANGUAGE LABORATORIES, A SERIES OF TESTS WHICH A NON-TECHNICAL PERSON CAN CONDUCT TO VERIFY SPECIFICATIONS.

    ERIC Educational Resources Information Center

    GRITTNER, FRANK; PAVLAT, RUSSELL

    IN ORDER TO ASSIST NON-TECHNICAL PEOPLE IN SCHOOLS TO CONDUCT A FIELD CHECK OF LANGUAGE LABORATORY EQUIPMENT BEFORE THEY MAKE FINAL PAYMENTS, THIS MANUAL OFFERS CRITERIA, TESTS, AND METHODS OF SCORING THE QUALITY OF THE EQUIPMENT. CHECKLISTS ARE PROVIDED FOR EVALUATING CONSOLE FUNCTIONS, TAPE RECORDERS, AMPLIFIERS, SOUND QUALITY (INCLUDING…

  12. Regional and field-specific factors affect the composition of Fusarium head blight pathogens in subtropical no-till wheat agroecosystem of Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A multiyear survey of >200 wheat fields in Paraná (PR) and Rio Grande do Sul (RS) states was conducted to assess the extent and distribution of Fusarium graminearum species complex (FGSC) diversity in the southern Brazilian wheat agroecosystem. Five species and three trichothecene genotypes were fou...

  13. RESEARCH PROGRAM FOR BRACE - PROVIDING NO AND SPECIFIC NO2 MEASUREMENTS FOR THE BRACE DATABASE DURING THE MAY '02 FIELD STUDY

    EPA Science Inventory

    Three scientists from the EPA, RTP facility in Research Triangle Park, N.C. worked with the State of Florida and BRACE scientists to provide accurate and precise NO and specific NO2 measurements at two monitoring sites, the rural Sydney site and the near-bay, suburban Gandy sit...

  14. Field assessment of host plant specificity and potential effectiveness of a prospective biological control agent, Aceria salsolae, of Russian thistle, Salsola tragus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The eriophyid mite, Aceria salsolae attacks several species of invasive alien tumbleweeds, including Salsola tragus, S. collina, S. paulsenii and S. australis, in North America. Previous laboratory experiments to determine host specificity of the mite indicated that it could sometimes persist and m...

  15. Ceratapion basicorne (Illiger) (Coleoptera: Curculionidae): laboratory and open field trials to assess its specificity as biocontrol agent of Centaurea solstitialis (Asteraceae: Cardueae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Prospective biological control agents generally must be demonstrated to not pose risks to non-target plants. Laboratory experiments evaluating host plant specificity are the most common method of evaluating such risk; however, they are constrained by limitations of space and number of replicates, gi...

  16. Genotype-specific responses of Bromus erectus to elevated CO{sub 2} at different levels of biodiversity and endophyte infection - a field experiment

    SciTech Connect

    Steinger, T.; Groppe, K.; Schmid, B. |

    1995-06-01

    In 1994 we initiated a long-term field experiment in a calcareous grassland to study the effects of elevated CO{sub 2} on individuals, populations, and communities. Clonal replicates of 54 genotypes of the dominant grass Bromus erectus were grown in communities planted at three levels of biodiversity (5-, 12-, 31-species plots) and exposed to ambient and elevated CO{sub 2}. The same genotypes were also individually grown in tubes within the field plots. Some genotypes were infected by the endophytic fungus Epichloee typhina. Elevated CO{sub 2} had no significant effects on plant growth, however, there was large variation among genotypes in all measured characters. A significant CO{sub 2}-by-genotype interaction was found for leaf length in the competition-free tubes. Infection by the endophyte led to the abortion of all inflorescences but increased vegetative growth, especially under competitive conditions.

  17. Dynamics of the large-scale open solar magnetic field and its specific features in the zone of the main active longitudes in 2006-2012

    NASA Astrophysics Data System (ADS)

    Ivanov, K. G.; Kharshiladze, A. F.

    2013-11-01

    The dynamics of the absolute global values (Φ) of the large-scale open solar magnetic field (LOSMF) fluxes at an interval of one solar rotation in 2006-2012 has been studied based on the Wilcox Solar Observatory data and using the ISOPAK original package for modeling the solar magnetic field. The reference points and the duration of the final quasi-biennial interval in cycle 23 (January 2006-May 2007; 17 months) and the phases of the cycle 24 minimum (May 2007-November 2009; 30 months), growth (November 2009-May 2012; 30 months), and the beginning of the maximum (May 2012-January 2013) have been determined. It has been indicated that the absolute values (Φ) decreased sharply at the beginning of the minimum, growth, and the maximum phases to ˜(2, 1.25, 0.75) × 1022 Mx, respectively. During the entire minimum phase, LOSMF corotated super-quasi-rigidly westward in the direction of solar rotation; at the beginning of the growth phase, this field started corotating mostly eastward. The LOSMF polarity reversal in the current cycle 24 started in May-June 2012 (CR 2123-2124), when fields of southern polarity rushed from the Sun's southern hemisphere toward the north. The statement that the solar cycle is a continuous series of quasi-biennial LOSMF intervals is confirmed. In particular, the minimum and growth phases are characterized by opposite LOSMF rotation directions, i.e., super-quasi-rigid corotation (twisting) and detwisting, with identical duration at least in cycle 24.

  18. Unit-specific calibration of Actigraph accelerometers in a mechanical setup – Is it worth the effort? The effect on random output variation caused by technical inter-instrument variability in the laboratory and in the field

    PubMed Central

    Moeller, Niels C; Korsholm, Lars; Kristensen, Peter L; Andersen, Lars B; Wedderkopp, Niels; Froberg, Karsten

    2008-01-01

    Background Potentially, unit-specific in-vitro calibration of accelerometers could increase field data quality and study power. However, reduced inter-unit variability would only be important if random instrument variability contributes considerably to the total variation in field data. Therefore, the primary aim of this study was to calculate and apply unit-specific calibration factors in multiple accelerometers in order to examine the impact on random output variation caused by inter-instrument variability. Methods Instrument-specific calibration factors were estimated in 25 MTI- and 53 CSA accelerometers in a mechanical setup using four different settings varying in frequencies and/or amplitudes. Calibration effect was analysed by comparing raw and calibrated data after applying unit-specific calibration factors to data obtained during quality checks in a mechanical setup and to data collected during free living conditions. Results Calibration reduced inter-instrument variability considerably in the mechanical setup, both in the MTI instruments (raw SDbetween units = 195 counts*min-1 vs. calibrated SDbetween units = 65 counts*min-1) and in the CSA instruments (raw SDbetween units = 343 counts*min-1 vs. calibrated SDbetween units = 67 counts*min-1). However, the effect of applying the derived calibration to children's and adolescents' free living physical activity data did not alter the coefficient of variation (CV) (children: CVraw = 30.2% vs. CVcalibrated = 30.4%, adolescents: CVraw = 36.3% vs. CVcalibrated = 35.7%). High correlations (r = 0.99 & r = 0.98, respectively) were observed between raw and calibrated field data, and the proportion of the total variation caused by the MTI- and CSA monitor was estimated to be only 1.1% and 4.2%, respectively. Compared to the CSA instruments, a significantly increased (9.95%) mean acceleration response was observed post hoc in the batch of MTI instruments, in which a significantly reduced inter-instrumental reliability

  19. Drilling Specifications: Well Installations in the 300 Area to Support PNNL’s Integrated Field-Scale Subsurface Research Challenge (IFC) Project

    SciTech Connect

    Bjornstad, Bruce N.; Vermeul, Vince R.

    2008-01-21

    Part of the 300 Area Integrated Field-Scale Subsurface Research Challenge (IFC) will be installation of a network of high density borings and wells to monitor migration of fluids and contaminants (uranium), both in groundwater and vadose zone, away from an surface infiltration plot (Figure A-1). The infiltration plot will be located over an area of suspected contamination at the former 300 Area South Process Pond (SPP). The SPP is located in the southeastern portion of the Hanford Site, within the 300-FF-5 Operable Unit. Pacific Northwest National Laboratory (PNNL) with the support of FH shall stake the well locations prior to the start of drilling. Final locations will be based on accessibility and will avoid any surface or underground structures or hazards as well as surface contamination.

  20. Membrane specific mapping and colocalization of malarial and host skeletal proteins in the Plasmodium falciparum infected erythrocyte by dual-color near-field scanning optical microscopy.

    PubMed

    Enderle, T; Ha, T; Ogletree, D F; Chemla, D S; Magowan, C; Weiss, S

    1997-01-21

    Accurate localization of proteins within the substructure of cells and cellular organelles enables better understanding of structure-function relationships, including elucidation of protein-protein interactions. We describe the use of a near-field scanning optical microscope (NSOM) to simultaneously map and detect colocalized proteins within a cell, with superresolution. The system we elected to study was that of human red blood cells invaded by the human malaria parasite Plasmodium falciparum. During intraerythrocytic growth, the parasite expresses proteins that are transported to the erythrocyte cell membrane. Association of parasite proteins with host skeletal proteins leads to modification of the erythrocyte membrane. We report on colocalization studies of parasite proteins with an erythrocyte skeletal protein. Host and parasite proteins were selectively labeled in indirect immunofluorescence antibody assays. Simultaneous dual-color excitation and detection with NSOM provided fluorescence maps together with topography of the cell membrane with subwavelength (100 nm) resolution. Colocalization studies with laser scanning confocal microscopy provided lower resolution (310 nm) fluorescence maps of cross sections through the cell. Because the two excitation colors shared the exact same near-field aperture, the two fluorescence images were acquired in perfect, pixel-by-pixel registry, free from chromatic aberrations, which contaminate laser scanning confocal microscopy measurements. Colocalization studies of the protein pairs of mature parasite-infected erythrocyte surface antigen (MESA) (parasite)/protein4.1(host) and P. falciparum histidine rich protein (PfHRP1) (parasite)/protein4.1(host) showed good real-space correlation for the MESA/protein4.1 pair, but relatively poor correlation for the PfHRP1/protein4.1 pair. These data imply that NSOM provides high resolution information on in situ interactions between proteins in biological membranes. This method of

  1. Note: steps taken to optimise probe specificity and signal intensity prior to field validation of the MIDTAL (Microarray for the Detection of Toxic Algae).

    PubMed

    Medlin, Linda K

    2013-10-01

    A microarray for the detection of toxic algal species was developed in the European Union 7th Framework project MIDTAL. We initially tested all available fluorescence in situ hybridisation probes for toxic algae, which are normally designed to a length of 18 nt, and found that in most cases the signal was rather weak or all probes designed from the second half of the molecule were inaccessible in a microarray format because of secondary structure of the ribosomal RNA molecule We modified the length of the probes, the fragmentation of the rRNA, the stringency of the washing buffers and the length of the spacer molecules linking the probes to the glass surface of the microarray. Because of the secondary structure of the rRNA molecule, regions of the molecule can be difficult to access by the probes. Each of these modifications has improved probe accessibility and probe specificity to reduce false positives. PMID:23636588

  2. Resistance and mutations of non-specificity in the field of anxiety-depressive disorders in Canadian medical journals, 1950-1990.

    PubMed

    Collin, Johanne; Otero, Marcelo

    2015-04-01

    Pharmaceuticalisation is a complex phenomenon, co-constitutive of what scholars identify as a pharmaceutical regime, comprised of networks of actors, institutions and artefacts as well as cognitive structures that underlie the production, promotion and use of medications. The aim of this paper is to explore the linkages between different components of this pharmaceutical regime through the analysis of psychotropic drug advertising in Canadian medical journals between 1950 and 1990. Advertisements stand at the nexus of macro-level processes related to the development, regulation and marketing of new drug treatments and of micro-level processes related to the use of these drug treatments, both by clinicians and lay persons. We thus examine advertisements from the angle of the mental and classificatory universes to which doctors were exposed through direct-to-prescriber advertisement strategies implemented during this period. Furthermore, we explore to what extent the rationale behind advertisements was permeated by both scientific/professional and popular narratives of mind-body connections. This paper demonstrates that, although this period was marked by paradigm shifts in the classification of mental diseases, the development of modern psychopharmacology, and the questioning of the scientific legitimacy of psychiatry, advertisements unveil a remarkable continuity: that of the mass management of anxiety-depressive disorders by primary care physicians through psychotropic drugs. Also, despite the effective resistance to specificity as shown by the constant redefinitions of diagnostic categories and therapeutic indications, our analysis suggests that the language of specificity used in the promotion of new drugs and in the various narratives of mind-body connection may have been appealing to general practitioners. Finally, our study of the classes of psychoactive medications that have been in use for over half a century reveals a complex, non-linear dynamic of

  3. The specific role of fungal community structure on soil aggregation and carbon sequestration: results from long-term field study in a paddy soil

    NASA Astrophysics Data System (ADS)

    Murugan, Rajasekaran; Kumar, Sanjay

    2015-04-01

    Soil aggregate stability is a crucial soil property that affects soil biota, biogeochemical processes and C sequestration. The relationship between soil aggregate stability and soil C cycling is well known but the influence of specific fungal community structure on this relationship is largely unknown in paddy soils. The aim of the present study was to evaluate the long-term fertilisation (mineral fertiliser-MIN; farmyard manure-FYM; groundnut oil cake-GOC) effects on soil fungal community shifts associated with soil aggregates under rice-monoculture (RRR) and rice-legume-rice (RLR) systems. Fungal and bacterial communities were characterized using phospholipid fatty acids, and glucosamine and muramic acid were used as biomarkers for fungal and bacterial residues, respectively. Microbial biomass C and N, fungal biomass and residues were significantly higher in the organic fertiliser treatments than in the MIN treatment, for all aggregate sizes under both crop rotation systems. In general, fungal/bacterial biomass ratio and fungal residue C/bacterial residue C ratio were significantly higher in macroaggregate fractions (> 2000 and 250-2000 μm) than in microaggregate fractions (53-250 and <53 μm). In both crop rotation systems, the long-term application of FYM and GOC led to increased accumulation of saprotrophic fungi (SF) in aggregate fractions > 2000 μm. In contrast, we found that arbuscular mycorrhizal fungi (AMF) was surprisingly higher in aggregate fractions > 2000 μm than in aggregate fraction 250-2000 μm under MIN treatment. The RLR system showed significantly higher AMF biomass and fungal residue C/ bacterial residue C ratio in both macroaggregate fractions compared to the RRR system. The strong relationships between SF, AMF and water stable aggregates shows the specific contribution of fungi community on soil aggregate stability. Our results highlight the fact that changes within fungal community structure play an important role in shaping the soil

  4. Patient-specific quality assurance for the delivery of 60Co intensity modulated radiation therapy subject to a 0.35 T lateral magnetic field

    PubMed Central

    Li, H. Harold; Rodriguez, Vivian L.; Green, Olga L.; Hu, Yanle; Kashani, Rojano; Wooten, H. Omar; Yang, Deshan; Mutic, Sasa

    2014-01-01

    Purpose This work describes a patient-specific dosimetry quality assurance (QA) program for intensity modulated radiation therapy (IMRT) using ViewRay, the first commercial magnetic resonance imaging guided radiation therapy device. Methods and materials The program consisted of the following components: 1) one-dimensional multipoint ionization chamber measurement using a customized 15 cm3 cubic phantom, 2) two-dimensional (2D) radiographic film measurement using a 30×30×20 cm3 phantom with multiple inserted ionization chambers, 3) quasi- three-dimensional (3D) diode array (ArcCHECK) measurement with a centrally inserted ionization chamber, 4) 2D fluence verification using machine delivery log files, and 5) 3D Monte-Carlo (MC) dose reconstruction with machine delivery files and phantom CT. Results The ionization chamber measurements agreed well with treatment planning system (TPS) computed doses in all phantom geometries where the mean difference (mean ± SD) was 0.0% ± 1.3% (n=102, range, −3.0 % to 2.9%). The film measurements also showed excellent agreement with the TPS computed 2D dose distributions where the mean passing rate using 3% relative/3 mm gamma criteria was 94.6% ± 3.4% (n=30, range, 87.4% to 100%). For ArcCHECK measurements, the mean passing rate using 3% relative/3 mm gamma criteria was 98.9% ± 1.1% (n=34, range, 95.8% to 100%). 2D fluence maps with a resolution of 1×1 mm2 showed 100% passing rates for all plan deliveries (n=34). The MC reconstructed doses to the phantom agreed well with planned 3D doses where the mean passing rate using 3% absolute/3 mm gamma criteria was 99.0% ± 1.0% (n=18, range, 97.0% to100%), demonstrating the feasibility of evaluating the QA results in the patient geometry. Conclusions We have developed a dosimetry program for ViewRay’s patient-specific IMRT QA. The methodology will be useful for other ViewRay users. The QA results presented here can assist the RT community to establish appropriate tolerance and

  5. Patient-Specific Quality Assurance for the Delivery of {sup 60}Co Intensity Modulated Radiation Therapy Subject to a 0.35-T Lateral Magnetic Field

    SciTech Connect

    Li, H. Harold Rodriguez, Vivian L.; Green, Olga L.; Hu, Yanle; Kashani, Rojano; Wooten, H. Omar; Yang, Deshan; Mutic, Sasa

    2015-01-01

    Purpose: This work describes a patient-specific dosimetry quality assurance (QA) program for intensity modulated radiation therapy (IMRT) using ViewRay, the first commercial magnetic resonance imaging-guided RT device. Methods and Materials: The program consisted of: (1) a 1-dimensional multipoint ionization chamber measurement using a customized 15-cm{sup 3} cube-shaped phantom; (2) 2-dimensional (2D) radiographic film measurement using a 30- × 30- × 20-cm{sup 3} phantom with multiple inserted ionization chambers; (3) quasi-3D diode array (ArcCHECK) measurement with a centrally inserted ionization chamber; (4) 2D fluence verification using machine delivery log files; and (5) 3D Monte Carlo (MC) dose reconstruction with machine delivery files and phantom CT. Results: Ionization chamber measurements agreed well with treatment planning system (TPS)-computed doses in all phantom geometries where the mean ± SD difference was 0.0% ± 1.3% (n=102; range, −3.0%-2.9%). Film measurements also showed excellent agreement with the TPS-computed 2D dose distributions where the mean passing rate using 3% relative/3 mm gamma criteria was 94.6% ± 3.4% (n=30; range, 87.4%-100%). For ArcCHECK measurements, the mean ± SD passing rate using 3% relative/3 mm gamma criteria was 98.9% ± 1.1% (n=34; range, 95.8%-100%). 2D fluence maps with a resolution of 1 × 1 mm{sup 2} showed 100% passing rates for all plan deliveries (n=34). The MC reconstructed doses to the phantom agreed well with planned 3D doses where the mean passing rate using 3% absolute/3 mm gamma criteria was 99.0% ± 1.0% (n=18; range, 97.0%-100%), demonstrating the feasibility of evaluating the QA results in the patient geometry. Conclusions: We developed a dosimetry program for ViewRay's patient-specific IMRT QA. The methodology will be useful for other ViewRay users. The QA results presented here can assist the RT community to establish appropriate tolerance and action limits for View

  6. Field estimation of the flock-level diagnostic specificity of an enzyme-linked immunosorbent assay for Avian metapneumovirus antibodies in turkeys.

    PubMed

    Muñoz-Zanzi, Claudia; Trampel, Darrell; Hanson, Tim; Harrison, Kristen; Goyal, Sagar; Cortinas, Roberto; Lauer, Dale

    2009-03-01

    Routine serologic testing for Avian metapneumovirus (AMPV) infection of turkey flocks at slaughter is currently being used to monitor changes in the occurrence of AMPV infection in endemic areas and can also be used to detect the emergence of infection in currently unaffected areas. Because of the costs associated with false-positive results, particularly in areas that are free of AMPV infection, there is a need to obtain improved estimates of flock-level specificity (SP). The objective of this study was to estimate flock-level SP of a program to monitor AMPV infection in turkey flocks at processing using a standard enzyme-linked immunosorbent assay (ELISA). A study was carried out in which 37 AMPV-free flocks from 7 Midwest operations were followed serologically. Six percent, 3%, and 0.2% of total samples tested AMPV positive at 8 weeks, 12 weeks, and at processing, respectively. Overall, flock-level SP increased as the cutoff increased and as age increased. Flock-level SP at processing was 97%, if a cutoff of 1 was used (the flock was classified as positive if at least 1 sample tested positive), and 100%, if any other cutoff was used. Administration of antibiotics (P = 0.02) and vaccination for Bordetella avium (P = 0.08) were positively associated with the probability of (false) positive test results. These findings suggest possible cross-reactions with other infections and highlight the need to consider variable diagnostic performance depending on farm conditions. PMID:19286505

  7. Rapid and specific detection of Sin Nombre virus antibodies in patients with hantavirus pulmonary syndrome by a strip immunoblot assay suitable for field diagnosis.

    PubMed Central

    Hjelle, B; Jenison, S; Torrez-Martinez, N; Herring, B; Quan, S; Polito, A; Pichuantes, S; Yamada, T; Morris, C; Elgh, F; Lee, H W; Artsob, H; Dinello, R

    1997-01-01

    To develop a rapid antibody test for Sin Nombre hantavirus (SNV) infection for diagnosis of hantavirus pulmonary syndrome (HPS) in field settings where advanced instrumentation is not available, a strip immunoblot assay bearing four immobilized antigens for SNV and a recombinant nucleocapsid protein antigen of Seoul hantavirus (SEOV) was prepared. The SNV antigens included a full-length recombinant-expressed nucleocapsid (N) protein (rN), a recombinant-expressed G1 protein (residues 35 to 117), and synthetic peptides derived from N (residues 17 to 59) and G1 (residues 55 to 88). On the basis of the observed reactivities of hantavirus-infected patient and control sera, we determined that a positive assay requires reactivity with SNV or SEOV rN antigen and at least one other antigen. Isolated reactivity to either viral rN antigen is indeterminate, and any pattern of reactivity that does not include reactivity to an rN antigen is considered indeterminate but is unlikely to represent hantavirus infection. Fifty-eight of 59 samples from patients with acute SNV-associated HPS were positive according to these criteria, and one was initially indeterminate. Four of four samples from patients with HPS due to other hantaviruses were positive, as were most samples from patients with SEOV and Puumala virus infections. Of 192 control serum samples, 2 (1%) were positive and 2 were indeterminate. Acute SNV infection was distinguishable from remote SNV infection or infection with hantaviruses other than SNV by the presence of G1 peptide antigen reactivities in the former. The strip immunoblot assay shows promise for the detection of SNV antibodies early in the course of HPS. PMID:9041397

  8. Specification Reformulation During Specification Validation

    NASA Technical Reports Server (NTRS)

    Benner, Kevin M.

    1992-01-01

    The goal of the ARIES Simulation Component (ASC) is to uncover behavioral errors by 'running' a specification at the earliest possible points during the specification development process. The problems to be overcome are the obvious ones the specification may be large, incomplete, underconstrained, and/or uncompilable. This paper describes how specification reformulation is used to mitigate these problems. ASC begins by decomposing validation into specific validation questions. Next, the specification is reformulated to abstract out all those features unrelated to the identified validation question thus creating a new specialized specification. ASC relies on a precise statement of the validation question and a careful application of transformations so as to preserve the essential specification semantics in the resulting specialized specification. This technique is a win if the resulting specialized specification is small enough so the user my easily handle any remaining obstacles to execution. This paper will: (1) describe what a validation question is; (2) outline analysis techniques for identifying what concepts are and are not relevant to a validation question; and (3) identify and apply transformations which remove these less relevant concepts while preserving those which are relevant.

  9. Military specifications

    NASA Technical Reports Server (NTRS)

    Reynolds, Philip

    1987-01-01

    The current situation relative to the military specification is that there is not one specific model of turbulence which people are using. Particular disagreement exists on how turbulence levels will vary with qualitative analysis. It does not tie one down to specifics. When it comes to flying quality specifications, many feel that one should stay with the definitions of the Cooper-Harper rating scale but allow the levels to shift depending on the level of turbulence. There is a ride quality specification in the MIL-SPEC having to do with flight control systems design that is related to a turbulence model. This spec (MIL-F8785C) and others are discussed.

  10. BLOCK DISPLACEMENT METHOD FIELD DEMONSTRATION AND SPECIFICATIONS

    EPA Science Inventory

    The Block Displacement technique has been developed as a remedial action method for isolating large tracks of ground contaminated by hazardous waste. The technique places a low permeability barrier around and under a large block of contaminated earth. The Block Displacement proce...

  11. Building Specifications

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The building in the top photo is the new home of the National Permanent Savings Bank in Washington, D.C., designed by Hartman-Cox Architects. Its construction was based on a money-saving method of preparing building specifications which derived from NASA technology developed to obtain quality construction while holding down cost of launch facilities, test centers and other structures. Written technical specifications spell out materials and components to be used on construction projects and identify the quality tests each item must pass. Specifications can have major impact on construction costs. Poorly formulated specifications can lead to unacceptable construction which must be replaced, unnecessarily high materials costs, safety hazards, disputes and often additional costs due to delays and litigation. NASA's Langley Research Center developed a novel approach to providing accurate, uniform, cost-effective specifications which can be readily updated to incorporate new building technologies. Called SPECSINTACT, it is a computerized - system accessible to all NASA centers involved in construction programs. The system contains a comprehensive catalog of master specifications applicable to many types of construction. It enables designers of any structure to call out relevant sections from computer storage and modify them to fit the needs of the project at hand. Architects and engineers can save time by concentrating their efforts on needed modifications rather than developing all specifications from scratch. Successful use of SPECSINTACT has led to a number of spinoff systems. One of the first was MASTERSPEC, developed from NASA's experience by Production Systems for Architects and Engineers, Inc., an organization established by the American Institute of Architects. MASTERSPEC, used in construction of the bank building pictured, follows the same basic format as SPECSINTACT and can be used in either automated or manual modes. The striking appearance of the bank

  12. Specifying Specification.

    PubMed

    Paulo, Norbert

    2016-03-01

    This paper tackles the accusation that applied ethics is no serious academic enterprise because it lacks theoretical bracing. It does so in two steps. In the first step I introduce and discuss a highly acclaimed method to guarantee stability in ethical theories: Henry Richardson's specification. The discussion shows how seriously ethicists take the stability of the connection between the foundational parts of their theories and their further development as well as their "application" to particular problems or cases. A detailed scrutiny of specification leads to the second step, where I use insights from legal theory to inform the debate around stability from that point of view. This view reveals some of specification's limitations. I suggest that, once specification is sufficiently specified, it appears astonishingly similar to deduction as used in legal theory. Legal theory also provides valuable insight into the functional range of deduction and its relation to other forms of reasoning. This leads to a richer understanding of stability in normative theories and to a smart division of labor between deduction and other forms of reasoning. The comparison to legal theory thereby provides a framework for how different methods such as specification, deduction, balancing, and analogy relate to one another. PMID:27157109

  13. Beyond Field Education: Leadership of Field Directors

    ERIC Educational Resources Information Center

    Wertheimer, Mindy R.; Sodhi, Mimi

    2014-01-01

    This article presents a conceptual model of the field director's role outside of field education, specifically in the following 3 areas of leadership: (1) curricular, (2) programmatic, and (3) institutional. A survey was conducted to explore the field director's input targeted in these areas beyond prescribed field education tasks. The…

  14. Quality-assurance results for field pH and specific-conductance measurements, and for laboratory analysis, National Atmospheric Deposition Program and National Trends Network; January 1980-September 1984

    USGS Publications Warehouse

    Schroder, L.J.; Brooks, M.H.; Malo, B.A.; Willoughby, T.C.

    1986-01-01

    Five intersite comparison studies for the field determination of pH and specific conductance, using simulated-precipitation samples, were conducted by the U.S.G.S. for the National Atmospheric Deposition Program and National Trends Network. These comparisons were performed to estimate the precision of pH and specific conductance determinations made by sampling-site operators. Simulated-precipitation samples were prepared from nitric acid and deionized water. The estimated standard deviation for site-operator determination of pH was 0.25 for pH values ranging from 3.79 to 4.64; the estimated standard deviation for specific conductance was 4.6 microsiemens/cm at 25 C for specific-conductance values ranging from 10.4 to 59.0 microsiemens/cm at 25 C. Performance-audit samples with known analyte concentrations were prepared by the U.S.G.S.and distributed to the National Atmospheric Deposition Program 's Central Analytical Laboratory. The differences between the National Atmospheric Deposition Program and national Trends Network-reported analyte concentrations and known analyte concentrations were calculated, and the bias and precision were determined. For 1983, concentrations of calcium, magnesium, sodium, and chloride were biased at the 99% confidence limit; concentrations of potassium and sulfate were unbiased at the 99% confidence limit. Four analytical laboratories routinely analyzing precipitation were evaluated in their analysis of identical natural- and simulated precipitation samples. Analyte bias for each laboratory was examined using analysis of variance coupled with Duncan 's multiple-range test on data produced by these laboratories, from the analysis of identical simulated-precipitation samples. Analyte precision for each laboratory has been estimated by calculating a pooled variance for each analyte. Interlaboratory comparability results may be used to normalize natural-precipitation chemistry data obtained from two or more of these laboratories. (Author

  15. Specific Dyslexia.

    ERIC Educational Resources Information Center

    Naidoo, Sandhya

    The investigation reported in this volume attempts to clarify some issues relating to the existence, nature, and causes of specific dyslexia. Based on an extended study of 98 boys of at least average intelligence with severe reading and spelling problems, the report provides detailed data relating to their developmental and perinatal histories,…

  16. Specific Suspicion

    ERIC Educational Resources Information Center

    Taylor, Kelley R.

    2009-01-01

    This article discusses a recent case decided by the U.S. Supreme Court which highlights the importance of having specific suspicions of misbehavior before conducting a strip search. The case involves an eighth-grade female student who was being strip-searched by a middle school assistant principal, a school nurse, and an administrative assistant…

  17. Facilities Specifications Guide.

    ERIC Educational Resources Information Center

    Athletic Business, 2000

    2000-01-01

    Provides line drawings of indoor and outdoor sporting fields reflecting the specifications and dimensional standards of each, including where additional information can be found. Sporting events from badminton, baseball, and basketball to lacrosse, swimming/diving, and volleyball are addressed. (GR)

  18. Exposure to a specific pulsed low-frequency magnetic field: A double-blind placebo-controlled study of effects on pain ratings in rheumatoid arthritis and fibromyalgia patients

    PubMed Central

    Shupak, Naomi M; McKay, Julia C; Nielson, Warren R; Rollman, Gary B; Prato, Frank S; Thomas, Alex W

    2006-01-01

    BACKGROUND Specific pulsed electromagnetic fields (PEMFs) have been shown to induce analgesia (antinociception) in snails, rodents and healthy human volunteers. OBJECTIVE The effect of specific PEMF exposure on pain and anxiety ratings was investigated in two patient populations. DESIGN A double-blind, randomized, placebo-controlled parallel design was used. METHOD The present study investigated the effects of an acute 30 min magnetic field exposure (less than or equal to 400 μTpk; less than 3 kHz) on pain (McGill Pain Questionnaire [MPQ], visual analogue scale [VAS]) and anxiety (VAS) ratings in female rheumatoid arthritis (RA) (n=13; mean age 52 years) and fibromyalgia (FM) patients (n=18; mean age 51 years) who received either the PEMF or sham exposure treatment. RESULTS A repeated measures analysis revealed a significant pre-post-testing by condition interaction for the MPQ Pain Rating Index total for the RA patients, F(1,11)=5.09, P<0.05, estimate of effect size = 0.32, power = 0.54. A significant pre-post-effect for the same variable was present for the FM patients, F(1,15=16.2, P<0.01, estimate of effect size = 0.52, power =0.96. Similar findings were found for MPQ subcomponents and the VAS (pain). There was no significant reduction in VAS anxiety ratings pre- to post-exposure for either the RA or FM patients. CONCLUSION These findings provide some initial support for the use of PEMF exposure in reducing pain in chronic pain populations and warrants continued investigation into the use of PEMF exposure for short-term pain relief. PMID:16770449

  19. Comparison between Steroid Binding to Progesterone Membrane Receptor α (mPRα) and to Progesterone Nuclear Receptor: Correlation with Physicochemical Properties Assessed by Comparative Molecular Field Analysis and Identification of mPRα-specific Agonists

    PubMed Central

    Kelder, Jan; Azevedo, Rita; Pang, Yefei; de Vlieg, Jacob; Dong, Jing; Thomas, Peter

    2010-01-01

    Recent results showing that the binding characteristics of 33 steroids for human membrane progesterone receptor alpha (hu-mPRα) differ from those for the nuclear progesterone receptor (nPR) suggest that hu-mPRα-specific agonists can be identified for investigating its physiological functions. The binding affinities of an additional 21 steroids for hu-mPRα were determined to explore the structure-activity relationships in more detail and to identify potent, specific mPRα agonists. Four synthetic progesterone derivatives with methyl or methylene groups on positions 18 or 19, 18a-methylprogesterone (18-CH3P4, Org OE 64-0), 13-ethenyl-18-norprogesterone (18-CH2P4, Org 33663-0), 19a-methylprogesterone (19-CH3P4, Org OD 13-0) and 10-ethenyl-19-norprogesterone (19-CH2P4, Org OD 02-0), showed similar or higher affinities than progesterone for hu-mPRα and displayed mPRα agonist activities in G-protein and MAP kinase activation assays. All four steroids also bound to the nPR in cytosolic fractions of MCF-7 cells. However, two compounds, 19-CH2P4 and 19-CH3P4, showed no nPR agonist activity in a nPR reporter assay and therefore are selective mPRα agonists suitable for physiological investigations. The structure-binding relationships of the combined series of 54 steroids for hu-mPRα deviated strikingly from those of a published set of 60 3-keto or 3-desoxy steroids for nPR. Close correlations were observed between the receptor binding affinities of the steroids and their physicochemical properties calculated by comparative molecular field analysis (CoMFA) for both hu-mPRα and nPR. A comparison of the CoMFA field graphs for the two receptors revealed several differences in the structural features required for binding to hu-mPRα and nPR which could be exploited to develop additional mPR-specific ligands. PMID:20096719

  20. Durability and shielding performance of borated Ceramicrete coatings in beta and gamma radiation fields

    NASA Astrophysics Data System (ADS)

    Wagh, Arun S.; Sayenko, S. Yu.; Dovbnya, A. N.; Shkuropatenko, V. A.; Tarasov, R. V.; Rybka, A. V.; Zakharchenko, A. A.

    2015-07-01

    Ceramicrete™, a chemically bonded phosphate ceramic, was developed for nuclear waste immobilization and nuclear radiation shielding. Ceramicrete products are fabricated by an acid-base reaction between magnesium oxide and mono potassium phosphate. Fillers are used to impart desired properties to the product. Ceramicrete's tailored compositions have resulted in several commercial structural products, including corrosion- and fire-protection coatings. Their borated version, called Borobond™, has been studied for its neutron shielding capabilities and is being used in structures built for storage of nuclear materials. This investigation assesses the durability and shielding performance of borated Ceramicrete coatings when exposed to gamma and beta radiations to predict the composition needed for optimal shielding performance in a realistic nuclear radiation field. Investigations were conducted using experimental data coupled with predictive Monte Carlo computer model. The results show that it is possible to produce products for simultaneous shielding of all three types of nuclear radiations, viz., neutrons, gamma-, and beta-rays. Additionally, because sprayable Ceramicrete coatings exhibit excellent corrosion- and fire-protection characteristics on steel, this research also establishes an opportunity to produce thick coatings to enhance the shielding performance of corrosion and fire protection coatings for use in high radiation environment in nuclear industry.

  1. Field Campaign Guidelines

    SciTech Connect

    Voyles, J. W.; Chapman, L. A.

    2015-12-01

    This document establishes a common set of guidelines for the Atmospheric Radiation Measurement (ARM) Climate Research Facility for planning, executing, and closing out field campaigns. The steps that guide individual field campaigns are described in the Field Campaign Tracking System and are specifically tailored to meet the scope of each field campaign.

  2. Specific phobias.

    PubMed

    Hamm, Alfons O

    2009-09-01

    Exposure based treatments in which patients are systematically confronted with their feared objects of situations are highly effective in the treatment of specific phobias and produce stable improvement both in reported fear and behavioral avoidance. Exposure in reality is more effective in most cases than exposure in sensu. For situations that are difficult to realize, exposure in virtual environments has become increasingly valuable. Exposure in vivo is clearly superior to pharmacotherapy, although cognitive enhancers have been successfully used recently to increase the effect of exposure therapy. The induction of relaxation is not a necessary precondition for exposure therapy. Rather the current mechanisms of change focus on extinction learning as being the central mechanism both on a cognitive level namely that the feared object is no longer associated with severely threatening consequence but also on an affective level, meaning that feared cue is no longer capable to activate the fear circuit in the brain. Accordingly future diagnostic categorizations of phobic disorders in the DSM-V should rather focus on the pattern of the fear response that needs to be changed than on the eliciting cues or situations that are avoided. PMID:19716991

  3. Intent Specifications

    NASA Technical Reports Server (NTRS)

    Leveson, Nancy G.

    1995-01-01

    We have been investigating the implications of using abstractions based on intent rather than the aggregation and information-hiding abstractions commonly used in software en- gineering: Cognitive psychologists have shown that intent abstraction is consistent with human problem-solving processes. We believe that new types of specifications and designs based on this concept can assist in understanding and specifying requirements, capturing the most important design rationale information in an efficient and economical way, and supporting the process of identifying and analyzing required changes to minimize the introduction of errors. The goal of hierarchical abstraction is to allow both top-down and bottom-up reasoning about a complex system. In computer science, we have made much use of (1) part-whole abstractions where each level of a hierarchy represents an aggregation of the components at a lower level and of (2) information-hiding abstractions where each level contains the same conceptual information but hides some details about the concepts, that is, each level is a refinement of the information at a higher level.

  4. Regional profiling for determination of genotype diversity of mastitis-specific Staphylococcus aureus lineage in Canada by use of clumping factor A, pulsed-field gel electrophoresis, and spa typing.

    PubMed

    Said, Kamaleldin B; Ismail, Johanne; Campbell, Jennifer; Mulvey, Michael R; Bourgault, Anne-Marie; Messier, Serge; Zhao, Xin

    2010-02-01

    One of the major concerns in global public health and the dairy industry is the emergence of host-specific virulent Staphylococcus aureus strains. The high degree of stability of the species genome renders detection of genetic microvariations difficult. Thus, approaches for the rapid tracking of specialized lineages are urgently needed. We used clumping factor A (clfA) to profile 87 bovine mastitis isolates from four regions in Canada and compared the results to those obtained by pulsed-field gel electrophoresis (PFGE) and spa typing. Twenty-five pulsotypes were obtained by PFGE with an index of discrimination of 0.91. These were assigned to six PFGE lineage groups A to F and seven spa types, including two novel ones. Group A had 48.3% of the isolates and group D had 43.7% of the isolates, while only 8% of the isolates were variable. The results of antimicrobial susceptibility testing indicated that all isolates were sensitive to methicillin and the non-beta-lactam antibiotics, while three isolates were resistant to penicillin and one isolate was resistant to tetracycline. All isolates had the clfA gene and belonged to 20 clfA repeat types with an index of discrimination of 0.90. The dominant clfA types, types X, Q, C, and Z, formed 82% and 43% of PFGE groups A and D, respectively, and had copy numbers that varied only within a narrow range of between 46 and 52 copies, implying clonal selection. The rest were variable and region specific. Furthermore, the dominant groups contained subpopulations in different regions across Canada. Sequence information confirmed the relatedness obtained by the use of clfA repeat copy numbers and other methods and further revealed the occurrence of full-repeat deletions and conserved host-specific codon-triplet position biases at 18-bp units. Thus, concordant with the results of PFGE and spa typing, clfA typing proved useful for revealing the clonal nature of the mastitis isolate lineage and for the rapid profiling of subpopulations

  5. Testing the Effects of DL-Alpha-Tocopherol Supplementation on Oxidative Damage, Total Antioxidant Protection and the Sex-Specific Responses of Reproductive Effort and Lifespan to Dietary Manipulation in Australian Field Crickets (Teleogryllus commodus).

    PubMed

    Archer, C Ruth; Hempenstall, Sarah; Royle, Nick J; Selman, Colin; Willis, Sheridan; Rapkin, James; Blount, Jon D; Hunt, John

    2015-01-01

    The oxidative stress theory predicts that the accumulation of oxidative damage causes aging. More generally, oxidative damage could be a cost of reproduction that reduces survival. Both of these hypotheses have mixed empirical support. To better understand the life-history consequences of oxidative damage, we fed male and female Australian field crickets (Teleogryllus commodus) four diets differing in their protein and carbohydrate content, which have sex-specific effects on reproductive effort and lifespan. We supplemented half of these crickets with the vitamin E isoform DL-alpha-tocopherol and measured the effects of nutrient intake on lifespan, reproduction, oxidative damage and antioxidant protection. We found a clear trade-off between reproductive effort and lifespan in females but not in males. In direct contrast to the oxidative stress theory, crickets fed diets that improved their lifespan had high levels of oxidative damage to proteins. Supplementation with DL-alpha-tocopherol did not significantly improve lifespan or reproductive effort. However, males fed diets that increased their reproductive investment experienced high oxidative damage to proteins. While this suggests that male reproductive effort could elevate oxidative damage, this was not associated with reduced male survival. Overall, these results provide little evidence that oxidative damage plays a central role in mediating life-history trade-offs in T. commodus. PMID:26783958

  6. Testing the Effects of dl-Alpha-Tocopherol Supplementation on Oxidative Damage, Total Antioxidant Protection and the Sex-Specific Responses of Reproductive Effort and Lifespan to Dietary Manipulation in Australian Field Crickets (Teleogryllus commodus)

    PubMed Central

    Archer, C. Ruth; Hempenstall, Sarah; Royle, Nick J.; Selman, Colin; Willis, Sheridan; Rapkin, James; Blount, Jon D.; Hunt, John

    2015-01-01

    The oxidative stress theory predicts that the accumulation of oxidative damage causes aging. More generally, oxidative damage could be a cost of reproduction that reduces survival. Both of these hypotheses have mixed empirical support. To better understand the life-history consequences of oxidative damage, we fed male and female Australian field crickets (Teleogryllus commodus) four diets differing in their protein and carbohydrate content, which have sex-specific effects on reproductive effort and lifespan. We supplemented half of these crickets with the vitamin E isoform dl-alpha-tocopherol and measured the effects of nutrient intake on lifespan, reproduction, oxidative damage and antioxidant protection. We found a clear trade-off between reproductive effort and lifespan in females but not in males. In direct contrast to the oxidative stress theory, crickets fed diets that improved their lifespan had high levels of oxidative damage to proteins. Supplementation with dl-alpha-tocopherol did not significantly improve lifespan or reproductive effort. However, males fed diets that increased their reproductive investment experienced high oxidative damage to proteins. While this suggests that male reproductive effort could elevate oxidative damage, this was not associated with reduced male survival. Overall, these results provide little evidence that oxidative damage plays a central role in mediating life-history trade-offs in T. commodus. PMID:26783958

  7. Fasciola hepatica: Specificity of a coproantigen ELISA test for diagnosis of fasciolosis in faecal samples from cattle and sheep concurrently infected with gastrointestinal nematodes, coccidians and/or rumen flukes (paramphistomes), under field conditions.

    PubMed

    Kajugu, P-E; Hanna, R E B; Edgar, H W; McMahon, C; Cooper, M; Gordon, A; Barley, J P; Malone, F E; Brennan, G P; Fairweather, I

    2015-09-15

    Chronic fasciolosis is often diagnosed by faecal egg counting (FEC), following concentration of the eggs in the sample by a zinc sulphate floatation method. However, concentration by a sedimentation technique gives improved sensitivity. Interpretation of FEC results for fasciolosis is complicated by factors such as the long pre-patent period and irregular egg shedding. Thus, FEC reduction tests (FECRT), when used alone, are not completely reliable for diagnosis of anthelmintic susceptibility or resistance in local fluke populations, especially when parasite burdens are small. A Fasciola hepatica coproantigen ELISA test has been introduced which more accurately reflects the presence of flukes in the host bile ducts in late pre-patent infections, and absence of flukes following successful chemotherapeutic intervention. The aim of the present study was to elucidate the specificity of the F. hepatica coproantigen ELISA technique, particularly regarding potential cross-reactivity with rumen fluke (paramphistome), gastrointestinal nematode and coccidian infections. The method involved parallel testing of a large battery of faecal samples from field-infected cattle and sheep using floatation and sedimentation FECs and coproantigen analysis. No evidence was found for significant false positivity in the F. hepatica coproantigen ELISA due to paramphistome, coccidian and/or gastrointestinal nematode co-infections. With sedimentation FECs less than 10 F. hepatica eggs per gram (epg), the likelihood of a positive coproantigen result for the sample progressively decreased. Diagnosis of fasciolosis should be based on consideration of both FEC and coproantigen ELISA findings, to ensure optimum sensitivity for pre-patent and low-level infections. PMID:26234898

  8. A field-grown transgenic tomato line expressing higher levels of polyamines reveals legume cover crop mulch-specific perturbations in fruit phenotype at the levels of metabolite profiles, gene expression, and agronomic characteristics

    PubMed Central

    Neelam, Anil; Cassol, Tatiana; Mehta, Roshni A.; Abdul-Baki, Aref A.; Sobolev, Anatoli P.; Goyal, Ravinder K.; Abbott, Judith; Segre, Anna L.; Handa, Avtar K.; Mattoo, Autar K.

    2008-01-01

    Genetic modification of crop plants to introduce desirable traits such as nutritional enhancement, disease and pest resistance, and enhanced crop productivity is increasingly seen as a promising technology for sustainable agriculture and boosting food production in the world. Independently, cultural practices that utilize alternative agriculture strategies including organic cultivation subscribe to sustainable agriculture by limiting chemical usage and reduced tillage. How the two together affect fruit metabolism or plant growth in the field or whether they are compatible has not yet been tested. Fruit-specific yeast S-adenosylmethionine decarboxylase (ySAMdc) line 579HO, and a control line 556AZ were grown in leguminous hairy vetch (Vicia villosa Roth) (HV) mulch and conventional black polyethylene (BP) mulch, and their fruit analysed. Significant genotype×mulch-dependent interactions on fruit phenotype were exemplified by differential profiles of 20 fruit metabolites such as amino acids, sugars, and organic acids. Expression patterns of the ySAMdc transgene, and tomato SAMdc, E8, PEPC, and ICDHc genes were compared between the two lines as a function of growth on either BP or HV mulch. HV mulch significantly stimulated the accumulation of asparagine, glutamate, glutamine, choline, and citrate concomitant with a decrease in glucose in the 556AZ fruits during ripening as compared to BP. It enables a metabolic system in tomato somewhat akin to the one in higher polyamine-accumulating transgenic fruit that have higher phytonutrient content. Finally, synergism was found between HV mulch and transgenic tomato in up-regulating N:C indicator genes PEPC and ICDHc in the fruit. PMID:18469323

  9. A field-grown transgenic tomato line expressing higher levels of polyamines reveals legume cover crop mulch-specific perturbations in fruit phenotype at the levels of metabolite profiles, gene expression, and agronomic characteristics.

    PubMed

    Neelam, Anil; Cassol, Tatiana; Mehta, Roshni A; Abdul-Baki, Aref A; Sobolev, Anatoli P; Goyal, Ravinder K; Abbott, Judith; Segre, Anna L; Handa, Avtar K; Mattoo, Autar K

    2008-01-01

    Genetic modification of crop plants to introduce desirable traits such as nutritional enhancement, disease and pest resistance, and enhanced crop productivity is increasingly seen as a promising technology for sustainable agriculture and boosting food production in the world. Independently, cultural practices that utilize alternative agriculture strategies including organic cultivation subscribe to sustainable agriculture by limiting chemical usage and reduced tillage. How the two together affect fruit metabolism or plant growth in the field or whether they are compatible has not yet been tested. Fruit-specific yeast S-adenosylmethionine decarboxylase (ySAMdc) line 579HO, and a control line 556AZ were grown in leguminous hairy vetch (Vicia villosa Roth) (HV) mulch and conventional black polyethylene (BP) mulch, and their fruit analysed. Significant genotypexmulch-dependent interactions on fruit phenotype were exemplified by differential profiles of 20 fruit metabolites such as amino acids, sugars, and organic acids. Expression patterns of the ySAMdc transgene, and tomato SAMdc, E8, PEPC, and ICDHc genes were compared between the two lines as a function of growth on either BP or HV mulch. HV mulch significantly stimulated the accumulation of asparagine, glutamate, glutamine, choline, and citrate concomitant with a decrease in glucose in the 556AZ fruits during ripening as compared to BP. It enables a metabolic system in tomato somewhat akin to the one in higher polyamine-accumulating transgenic fruit that have higher phytonutrient content. Finally, synergism was found between HV mulch and transgenic tomato in up-regulating N:C indicator genes PEPC and ICDHc in the fruit. PMID:18469323

  10. Component-specific modeling

    NASA Technical Reports Server (NTRS)

    Mcknight, R. L.

    1985-01-01

    A series of interdisciplinary modeling and analysis techniques that were specialized to address three specific hot section components are presented. These techniques will incorporate data as well as theoretical methods from many diverse areas including cycle and performance analysis, heat transfer analysis, linear and nonlinear stress analysis, and mission analysis. Building on the proven techniques already available in these fields, the new methods developed will be integrated into computer codes to provide an accurate, and unified approach to analyzing combustor burner liners, hollow air cooled turbine blades, and air cooled turbine vanes. For these components, the methods developed will predict temperature, deformation, stress and strain histories throughout a complete flight mission.

  11. ENVIRONMENTAL SPECIFICATION REQUIREMENTS

    SciTech Connect

    TIFFT, S.R.

    2003-10-07

    Through regulations, permitting or binding negotiations, Regulators establish requirements, limits, permit conditions and Notice of Construction (NOC) conditions with which the Office of River Protection (ORP) and the Tank Farm Contractor (TFC) must comply. Operating Specifications are technical limits which are set on a process to prevent injury to personnel, or damage to the facility or environment. The main purpose of this document is to provide specification limits and recovery actions for the TFC Environmental Surveillance Program at the Hanford Site. Specification limits are given for monitoring frequencies and permissible variation of readings from an established baseline or previous reading. The requirements in this document are driven by environmental considerations and data analysis issues, rather than facility design or personnel safety issues. This document is applicable to all single-shell tank (SST) and double-shell tank (DST) waste tanks, and the associated catch tanks and receiver tanks, and transfer systems. This Tank Farm Environmental Specifications Document (ESD) implements environmental-regulatory limits on the configuration and operation of the Hanford Tank Farms facility that have been established by Regulators. This ESD contains specific field operational limits and recovery actions for compliance with airborne effluent regulations and agreements, liquid effluents regulations and agreements, and environmental tank system requirements. The scope of this ESD is limited to conditions that have direct impact on Operations Projects or that Operations/Projects have direct impact upon. This document does not supercede or replace any DOE Orders, regulatory permits, notices of construction, or Regulatory agency agreements binding on the ORP or the TFC. Refer to the appropriate regulation, permit, or NOC for an inclusive listing of requirements.

  12. Electric Field Imaging Project

    NASA Technical Reports Server (NTRS)

    Wilcutt, Terrence; Hughitt, Brian; Burke, Eric; Generazio, Edward

    2016-01-01

    NDE historically has focused technology development in propagating wave phenomena with little attention to the field of electrostatics and emanating electric fields. This work is intended to bring electrostatic imaging to the forefront of new inspection technologies, and new technologies in general. The specific goals are to specify the electric potential and electric field including the electric field spatial components emanating from, to, and throughout volumes containing objects or in free space.

  13. Mixed field peronnel dosimetry: Part 1, High temperature peak characteristics of the reader-annealed TLD-600

    SciTech Connect

    Liu, J.C. ); Sims, C.S. )

    1991-02-01

    The high temperature peaks (TL peaks 6--7) of TLD-600 are known to have higher responses to high LET radiation than to low LET radiation. These high temperature peak characteristics were studied for the automatic reader-annealed Harshaw albedo neutron TLD. The high temperature peaks response is linear for neutrons over the dose equivalent range tested (0.05--3 mSv of a {sup 252}Cf source moderated by a 15 cm radius polyethylene sphere), but is supralinear above 20 mSv of {sup 137}Cs photons. The peaks ratio (peaks 6--7/peaks 3--5) of TLD-600 is 0.15 for neutrons of any incident energy, 0.01 for {sup 137}Cs gammas, and 0.02 for M-150 x-rays. Based on the high temperature peak characteristics, a mixed field neutron-photon personnel dosimetry methodology using a single TLD-600 element was developed. The dosimetric method was evaluated in mixed {sup 238}PuBe + {sup 137}Cs fields with four neutron-gamma dose equivalent ratios, and the neutron, photon and total dose equivalent estimations are better than 20% except in one case. However, it was found that the neutron and photon dose equivalent estimations are sensitive to the neutron and photon peaks ratios, depending on the neutron-photon dose equivalent ratio and the neutron source in the mixed field. Therefore, a successful use of this method requires knowledge of the photon and neutron energies in the mixed field. 13 refs., 6 figs., 2 tabs.

  14. ENVIRONMENTAL SPECIFICATION REQUIREMENTS

    SciTech Connect

    TIFFT, S.R.

    2003-11-03

    Through regulations, permitting or binding negotiations, Regulators establish requirements, limits, permit conditions and Notice of Construction (NOC) conditions with which the Office of River Protection (ORP) and the Tank Farm Contractor (TFC) must comply. Operating Specifications are technical limits which are set on a process to prevent injury to personnel, or damage to the facility or environment. The main purpose of this document is to provide specification limits and recovery actions for the TFC Environmental Surveillance Program at the Hanford Site. Specification limits are given for monitoring frequencies and permissible variation of readings from an established baseline or previous reading. The requirements in this document are driven by environmental considerations and data analysis issues, rather than facility design or personnel safety issues. This document is applicable to all SST and DST waste tanks, and the associated catch tanks and receiver tanks, and transfer systems. This Tank Farm ESD implements environmental-regulatory limits on the configuration and operation of the Hanford Tank Farms facility that have been established by Regulators. This ESD contains specific field operational limits and recovery actions for compliance with airborne effluent regulations and agreements, liquid effluents regulations and agreements, and environmental tank system requirements. The scope of this ESD is limited to conditions that have direct impact on Operations/Projects or that Operations/Projects have direct impact upon. This document does not supercede or replace any DOE Orders, regulatory permits, notices of construction, or Regulatory agency agreements binding on the ORP or the TFC. Refer to the appropriate regulation, permit, or NOC for an inclusive listing of requirements.

  15. Component-specific modeling

    NASA Technical Reports Server (NTRS)

    Mcknight, R. L.

    1984-01-01

    A series of interdisciplinary modeling and analysis techniques that were specialized to address three specific hot section components are presented. These techniques will incorporate data as well as theoretical methods from many diverse areas including cycle and performance analysis, heat transfer analysis, linear and nonlinear stress analysis, and mission analysis. Building on the proven techniques already available in these fields, the new methods developed will be integrated into computer codes to provide an accurate, efficient and unified approach to analyzing combustor burner liners, hollow air-cooled turbine blades and air-cooled turbine vanes. For these components, the methods developed will predict temperature, deformation, stress and strain histories throughout a complete flight mission.

  16. Psychological Assessment of Patrolman Qualifications in Relation to Field Performance; The Identification of Predictors for Overall Performance of Patrolmen and the Relation between Predictors and Specific Patterns of Exceptional and Marginal Performance.

    ERIC Educational Resources Information Center

    Chicago Police Dept., IL.

    Behavioral scientists have been slow in the development of effective procedures and in empirical validation of psychological testing instruments for selecting law enforcement personnel. This study involved 253 supervisory sergeants and field lieutenants and 2,327 uniformed patrolmen of the Chicago Police Department (CPD). Three major performance…

  17. Simulation of the Mg(Ar) ionization chamber currents by different Monte Carlo codes in benchmark gamma fields

    NASA Astrophysics Data System (ADS)

    Lin, Yi-Chun; Liu, Yuan-Hao; Nievaart, Sander; Chen, Yen-Fu; Wu, Shu-Wei; Chou, Wen-Tsae; Jiang, Shiang-Huei

    2011-10-01

    High energy photon (over 10 MeV) and neutron beams adopted in radiobiology and radiotherapy always produce mixed neutron/gamma-ray fields. The Mg(Ar) ionization chambers are commonly applied to determine the gamma-ray dose because of its neutron insensitive characteristic. Nowadays, many perturbation corrections for accurate dose estimation and lots of treatment planning systems are based on Monte Carlo technique. The Monte Carlo codes EGSnrc, FLUKA, GEANT4, MCNP5, and MCNPX were used to evaluate energy dependent response functions of the Exradin M2 Mg(Ar) ionization chamber to a parallel photon beam with mono-energies from 20 keV to 20 MeV. For the sake of validation, measurements were carefully performed in well-defined (a) primary M-100 X-ray calibration field, (b) primary 60Co calibration beam, (c) 6-MV, and (d) 10-MV therapeutic beams in hospital. At energy region below 100 keV, MCNP5 and MCNPX both had lower responses than other codes. For energies above 1 MeV, the MCNP ITS-mode greatly resembled other three codes and the differences were within 5%. Comparing to the measured currents, MCNP5 and MCNPX using ITS-mode had perfect agreement with the 60Co, and 10-MV beams. But at X-ray energy region, the derivations reached 17%. This work shows us a better insight into the performance of different Monte Carlo codes in photon-electron transport calculation. Regarding the application of the mixed field dosimetry like BNCT, MCNP with ITS-mode is recognized as the most suitable tool by this work.

  18. Visual field

    MedlinePlus

    Perimetry; Tangent screen exam; Automated perimetry exam; Goldmann visual field exam; Humphrey visual field exam ... Confrontation visual field exam : This is a quick and basic check of the visual field. The health care provider ...

  19. Visual field

    MedlinePlus

    Perimetry; Tangent screen exam; Automated perimetry exam; Goldmann visual field exam; Humphrey visual field exam ... Confrontation visual field exam : This is a quick and basic check of the visual field. The health care provider sits directly in front ...

  20. Magnetic field generator

    DOEpatents

    Krienin, Frank

    1990-01-01

    A magnetic field generating device provides a useful magnetic field within a specific retgion, while keeping nearby surrounding regions virtually field free. By placing an appropriate current density along a flux line of the source, the stray field effects of the generator may be contained. One current carrying structure may support a truncated cosine distribution, and it may be surrounded by a current structure which follows a flux line that would occur in a full coaxial double cosine distribution. Strong magnetic fields may be generated and contained using superconducting cables to approximate required current surfaces.

  1. Gauge fields

    SciTech Connect

    Mills, R.

    1989-06-01

    This article is a survey of the history and ideas of gauge theory. Described here are the gradual emergence of symmetry as a driving force in the shaping of physical theory; the elevation of Noether's theorem, relating symmetries to conservation laws, to a fundamental principle of nature; and the force of the idea (''the gauge principle'') that the symmetries of nature, like the interactions themselves, should be local in character. The fundamental role of gauge fields in mediating the interactions of physics springs from Noether's theorem and the gauge principle in a remarkably clean and elegant way, leaving, however, some tantalizing loose ends that might prove to be the clue to a future deeper level of understanding. The example of the electromagnetic field as the prototype gauge theory is discussed in some detail and serves as the basis for examining the similarities and differences that emerge in generalizing to non-Abelian gauge theories. The article concludes with a brief examination of the dream of total unification: all the forces of nature in a single unified gauge theory, with the differences among the forces due to the specific way in which the fundamental symmetries are broken in the local environment.

  2. Testing of regolith of celestial bolides with active neutron gamma-ray spectrometry

    NASA Astrophysics Data System (ADS)

    Vostrukhin, Andrey; Mitrofanov, Igor; Golovin, Dmitry; Litvak, Maxim; Sanin, Anton

    2015-04-01

    Current space instruments for studying planet's surface include gamma ray spectrometers that detect natural radioactive isotopes as well as gamma-rays induced in subsurface by galactic cosmic rays. When measuring from celestial body's surface, statistics and amount of detected elements can be dramatically increased with active methods, where soil exposed to artificial flux of particles. One good example is the Russian Dynamic Albedo of Neutron (DAN) instrument onboard Martian Science Laboratory mission (Curiosity rover) developed in 2005-2011. It is the first active neutron spectrometer flown to another planet as part of a landed mission to investigate subsurface water distribution and which has now successfully operated for more than two years on the Martian surface. Presentation describes a number of space instruments for different landers and rovers being developed in Russian Space Research Institute for studying Moon and Mars, as well as method of active neutron and gamma spectrometry overview.

  3. Multigroup Neutron/Gamma-Ray Direct Integration Transport Code System for Two-Dimensional Cylindrical Geometry.

    Energy Science and Technology Software Center (ESTSC)

    1980-10-15

    Version 00 PALLAS-2DCY-FX is a code for direct integration of the transport equation in two-dimensional (r,z) geometry. It solves the energy and angular-dependent Boltzmann transport equation with general anisotropic scattering in cylindrical geometry. Its principal applications are to neutron or gamma-ray transport problems in the forward mode. The code is particularly designed for and suited to the solution of deep penetration radiation transport problems with an external (fixed) source.

  4. Improved pulse shape discriminator for fast neutron-gamma ray detection system

    NASA Technical Reports Server (NTRS)

    Lockwood, J. A.; St. Onge, R.

    1969-01-01

    Discriminator in nuclear particle detection system distinguishes nuclear particle type and energy among many different nuclear particles. Discriminator incorporates passive, linear circuit elements so that it will operate over a wide dynamic range.

  5. Time-resolved Neutron-gamma-ray Data Acquisition for in Situ Subsurface Planetary Geochemistry

    NASA Technical Reports Server (NTRS)

    Bodnarik, Julie G.; Burger, Dan Michael; Burger, A.; Evans, L. G.; Parsons, A. M.; Schweitzer, J. S.; Starr R. D.; Stassun, K. G.

    2013-01-01

    The current gamma-ray/neutron instrumentation development effort at NASA Goddard Space Flight Center aims to extend the use of active pulsed neutron interrogation techniques to probe the subsurface elemental composition of planetary bodies in situ. Previous NASA planetary science missions, that used neutron and/or gamma-ray spectroscopy instruments, have relied on neutrons produced from galactic cosmic rays. One of the distinguishing features of this effort is the inclusion of a high intensity 14.1 MeV pulsed neutron generator synchronized with a custom data acquisition system to time each event relative to the pulse. With usually only one opportunity to collect data, it is difficult to set a priori time-gating windows to obtain the best possible results. Acquiring time-tagged, event-by-event data from nuclear induced reactions provides raw data sets containing channel/energy, and event time for each gamma ray or neutron detected. The resulting data set can be plotted as a function of time or energy using optimized analysis windows after the data are acquired. Time windows can now be chosen to produce energy spectra that yield the most statistically significant and accurate elemental composition results that can be derived from the complete data set. The advantages of post-processing gamma-ray time-tagged event-by-event data in experimental tests using our prototype instrument will be demonstrated.

  6. [sup 3]He neutron detector performance in mixed neutron gamma environments

    SciTech Connect

    Johnson, N. H.; Beddingfield, D. H.

    2002-01-01

    A test program of the performance of 3He neutron proportional detectors with varying gas pressures, and their response to lligh level gamma-ray exposure in a mixed neutrodgamma environment, ha$ been performed Our intent was to identie the optimal gas pressure to reduce the gamma-ray sensitivity of these detectors. These detectors were manufxtured using materials to minimize their gamma response. Earlier work focused on 3He fill pressures of four atmospheres and above, whereas the present work focuses on a wider range of pressures. Tests have shown that reducing the .filling pressure will M e r increase the gamma-ray dose range in which the detectors can be operated.

  7. A dual neutron/gamma source for the Fissmat Inspection for Nuclear Detection (FIND) system.

    SciTech Connect

    Doyle, Barney Lee; King, Michael; Rossi, Paolo; McDaniel, Floyd Del; Morse, Daniel Henry; Antolak, Arlyn J.; Provencio, Paula Polyak; Raber, Thomas N.

    2008-12-01

    Shielded special nuclear material (SNM) is very difficult to detect and new technologies are needed to clear alarms and verify the presence of SNM. High-energy photons and neutrons can be used to actively interrogate for heavily shielded SNM, such as highly enriched uranium (HEU), since neutrons can penetrate gamma-ray shielding and gamma-rays can penetrate neutron shielding. Both source particles then induce unique detectable signals from fission. In this LDRD, we explored a new type of interrogation source that uses low-energy proton- or deuteron-induced nuclear reactions to generate high fluxes of mono-energetic gammas or neutrons. Accelerator-based experiments, computational studies, and prototype source tests were performed to obtain a better understanding of (1) the flux requirements, (2) fission-induced signals, background, and interferences, and (3) operational performance of the source. The results of this research led to the development and testing of an axial-type gamma tube source and the design/construction of a high power coaxial-type gamma generator based on the {sup 11}B(p,{gamma}){sup 12}C nuclear reaction.

  8. Investigating the anisotropic scintillation response in anthracene through neutron, gamma-ray, and muon measurements

    DOE PAGESBeta

    Schuster, Patricia; Brubaker, Erik

    2016-05-05

    Our paper reports a series of measurements that characterize the directional dependence of the scintillation response of crystalline anthracene to incident DT neutrons, DD neutrons, 137Cs gamma rays, and, for the first time, cosmic ray muons. Moreover, the neutron measurements give the amplitude and pulse shape dependence on the proton recoil direction over one hemisphere of the crystal, confirming and extending previous results in the literature. In similar measurements using incident gamma rays, no directional effect is evident, and any anisotropy with respect to the electron recoil direction is constrained to have a magnitude of less than a tenth ofmore » that present in the proton recoil events. Cosmic muons are measured at two directions, and no anisotropy is observed. Our set of observations indicates that high dE/dx is necessary for an anisotropy to be present for a given type of scintillation event, which in turn could be used to discriminate among different hypotheses for the underlying causes of the anisotropy, which are not well understood.« less

  9. Anisn-Dort Neutron-Gamma Flux Intercomparison Exercise for a Simple Testing Model

    NASA Astrophysics Data System (ADS)

    Boehmer, B.; Konheiser, J.; Borodkin, G.; Brodkin, E.; Egorov, A.; Kozhevnikov, A.; Zaritsky, S.; Manturov, G.; Voloschenko, A.

    2003-06-01

    The ability of transport codes ANISN, DORT, ROZ-6, MCNP and TRAMO, as well as nuclear data libraries BUGLE-96, ABBN-93, VITAMIN-B6 and ENDF/B-6 to deliver consistent gamma and neutron flux results was tested in the calculation of a one-dimensional cylindrical model consisting of a homogeneous core and an outer zone with a single material. Model variants with H2O, Fe, Cr and Ni in the outer zones were investigated. The results are compared with MCNP-ENDF/B-6 results. Discrepancies are discussed. The specified test model is proposed as a computational benchmark for testing calculation codes and data libraries.

  10. Water detection at the moon, Mars and comets with a combined neutron gamma ray instrument

    NASA Technical Reports Server (NTRS)

    Metzger, Albert E.; Haines, Eldon L.

    1991-01-01

    Measuring the fluxes of thermal and epithermal neutrons at a planetary object in conjunction with gamma-ray spectroscopic observations will provide information about the chemical composition of the surface which is less model dependent than the gamma ray measurements by themselves. Researchers devised a passive neutron detector for this purpose. An experimental model was designed and built. Three variables provided the basis for a set of experiments: thickness of the Sm and B layers, the presence or absence of the ACS, and the position of the source relative to the PND's cylindrical axis. Experimental results are given.

  11. Simulation study of the neutron-gamma discrimination capability of a liquid scintillator neutron detector

    NASA Astrophysics Data System (ADS)

    Xing, Haoyang; Yu, Xunzhen; Zhu, Jingjun; Wang, Li; Ma, Jinglu; Liu, Shukui; Li, Linwei; Chen, Liejian; Tang, Changjian; Yue, Qian

    2014-12-01

    The capability to discriminate between neutrons and gamma rays (n/γ) by means of their pulse shapes is important for many users of liquid scintillator (LS) neutron detectors. To simulate the n/γ discrimination capability of a neutron detector, we have developed a method to simulate the pulse signal generated by an incident n or γ in the LS. Light pulses caused by ionization and excitation from incident n or γ radiation are simulated by the Geant4 simulation package based on the geometry and materials of a prototype LS detector. The response to the incident light of the photomultiplier tube (PMT) and data acquisition (DAQ) circuit was obtained from a single photoelectron experiment. The final output signal from a detector was produced by convolving its light pulse with the response function of the PMT and DAQ. Two methods, the charge comparison method (CCM) and the pulse gradient method (PGM), were applied to discriminate the simulated signals. The simulation was validated by comparing its result to an experimental result from the prototype LS detector. Our method can be applied in the design of an LS detector, which has subsequently been optimized n/γ discrimination. The method can also be helpful to analyze experimental data and evaluate the performance of n/γ discrimination techniques.

  12. Investigating the Anisotropic Scintillation Response in Anthracene through Neutron, Gamma-Ray, and Muon Measurements

    SciTech Connect

    Schuster, Patricia; Brubaker, Erik

    2016-01-01

    Our paper reports a series of measurements that characterize the directional dependence of the scintillation response of crystalline anthracene to incident DT neutrons, DD neutrons, 137Cs gamma rays, and, for the first time, cosmic ray muons. Moreover, the neutron measurements give the amplitude and pulse shape dependence on the proton recoil direction over one hemisphere of the crystal, confirming and extending previous results in the literature. In similar measurements using incident gamma rays, no directional effect is evident, and any anisotropy with respect to the electron recoil direction is constrained to have a magnitude of less than a tenth of that present in the proton recoil events. Cosmic muons are measured at two directions, and no anisotropy is observed. Our set of observations indicates that high dE/dx is necessary for an anisotropy to be present for a given type of scintillation event, which in turn could be used to discriminate among different hypotheses for the underlying causes of the anisotropy, which are not well understood.

  13. Neutron/gamma pulse shape discrimination (PSD) in plastic scintillators with digital PSD electronics

    NASA Astrophysics Data System (ADS)

    Hutcheson, Anthony L.; Simonson, Duane L.; Christophersen, Marc; Phlips, Bernard F.; Charipar, Nicholas A.; Piqué, Alberto

    2013-05-01

    Pulse shape discrimination (PSD) is a common method to distinguish between pulses produced by gamma rays and neutrons in scintillator detectors. This technique takes advantage of the property of many scintillators that excitations by recoil protons and electrons produce pulses with different characteristic shapes. Unfortunately, many scintillating materials with good PSD properties have other, undesirable properties such as flammability, toxicity, low availability, high cost, and/or limited size. In contrast, plastic scintillator detectors are relatively low-cost, and easily handled and mass-produced. Recent studies have demonstrated efficient PSD in plastic scintillators using a high concentration of fluorescent dyes. To further investigate the PSD properties of such systems, mixed plastic scintillator samples were produced and tested. The addition of up to 30 wt. % diphenyloxazole (DPO) and other chromophores in polyvinyltoluene (PVT) results in efficient detection with commercial detectors. These plastic scintillators are produced in large diameters up to 4 inches by melt blending directly in a container suitable for in-line detector use. This allows recycling and reuse of materials while varying the compositions. This strategy also avoids additional sample handling and polishing steps required when using removable molds. In this presentation, results will be presented for different mixed-plastic compositions and compared with known scintillating materials

  14. Design and performance of a new high accuracy combined small sample neutron/gamma detector

    SciTech Connect

    Menlove, H.; Davidson, D.; Verplancke, J.; Vermeulen, P.; Wagner, H.G.; Wellum, R.; Brandelise, B.; Mayer, K.

    1993-08-01

    This paper describes the design of an optimized combined neutron and gamma detector installed around a measurement well protruding from the floor of a glove box. The objective of this design was to achieve an overall accuracy for the plutonium element concentration in gram-sized samples of plutonium oxide powder approaching the {approximately}0.1--0.2% accuracies routinely achieved by inspectors` chemical analysis. The efficiency of the clam-shell neutron detector was increased and the flat response zone extended in axial and radial directions. The sample holder introduced from within the glove box was designed to form the upper reflector, while two graphite half-shells fitted around the thin neck of the high-resolution LEGE detector replaced the lower plug. The Institute for Reference Materials and Measurements (IRMM) in Geel prepared special plutonium oxide test samples whose plutonium concentration was determined to better than 0.05%. During a three week initial performance test in July 1992 at ITU Karlsruhe and in long term tests, it was established that the target accuracy can be achieved provided sufficient care is taken to assure the reproducibility of sample bottling and sample positioning. The paper presents and discusses the results of all test measurements.

  15. Design and performance of a new high accuracy combined small sample neutron/gamma detector

    SciTech Connect

    Menlove, H.; Davidson, D.; Verplancke, J.; Vermeulen, P.; Wagner, H.G.; Wellum, R.; Brandelise, B.; Mayer, K.

    1993-12-31

    This paper describes the design of an optimized combined neutron and gamma detector installed around a measurement well protruding from the floor of a glove box. The objective of this design was to achieve an overall accuracy for the plutonium element concentration in gram-sized samples of plutonium oxide powder approaching the {approximately}0.1--0.2% accuracies routinely achieved by inspectors` chemical analysis. The efficiency of the clam-shell neutron detector was increased and the flat response zone extended in axial and radial directions. The sample holder introduced from within the glove box was designed to form the upper reflector, while two graphite half-shells fitted around the thin neck of the high-resolution LEGe detector replaced the lower plug. The Institute for Reference Materials and Measurements (IRMM) in Geel prepared special plutonium oxide test samples whose plutonium concentration was determined to better than 0.05%. During a three week initial performance test in July 1992 at ITU Karlsruhe and in long term tests, it was established that the target accuracy can be achieved provided sufficient care is taken to assure the reproducibility of sample bottling and sample positioning. The paper presents and discusses the results of all test measurements.

  16. Time-resolved neutron/gamma-ray data acquisition for in situ subsurface planetary geochemistry

    NASA Astrophysics Data System (ADS)

    Bodnarik, J. G.; Burger, D. M.; Burger, A.; Evans, L. G.; Parsons, A. M.; Schweitzer, J. S.; Starr, R. D.; Stassun, K. G.

    2013-04-01

    The current gamma-ray/neutron instrumentation development effort at NASA Goddard Space Flight Center aims to extend the use of active pulsed neutron interrogation techniques to probe the subsurface elemental composition of planetary bodies in situ. Previous NASA planetary science missions, that used neutron and/or gamma-ray spectroscopy instruments, have relied on neutrons produced from galactic cosmic rays. One of the distinguishing features of this effort is the inclusion of a high intensity 14.1 MeV pulsed neutron generator synchronized with a custom data acquisition system to time each event relative to the pulse. With usually only one opportunity to collect data, it is difficult to set a priori time-gating windows to obtain the best possible results. Acquiring time-tagged, event-by-event data from nuclear induced reactions provides raw data sets containing channel/energy, and event time for each gamma ray or neutron detected. The resulting data set can be plotted as a function of time or energy using optimized analysis windows after the data are acquired. Time windows can now be chosen to produce energy spectra that yield the most statistically significant and accurate elemental composition results that can be derived from the complete data set. The advantages of post-processing gamma-ray time-tagged event-by-event data in experimental tests using our prototype instrument will be demonstrated.

  17. SU-E-T-594: Out-Of-Field Neutron and Gamma Dose Estimated Using TLD-600/700 Pairs in the Wobbling Proton Therapy System

    SciTech Connect

    Chen, Y; Lin, Y; Tsai, H

    2015-06-15

    Purpose: Secondary fast neutrons and gamma rays are mainly produced due to the interaction of the primary proton beam with the beam delivery nozzle. These secondary radiation dose to patients and radiation workers are unwanted. The purpose of this study is to estimate the neutron and gamma dose equivalent out of the treatment volume during the wobbling proton therapy system. Methods: Two types of thermoluminescent (TL) dosimeters, TLD-600 ({sup 6}LiF: Mg, Ti) and TLD-700 ({sup 7}LiF: Mg, Ti) were used in this study. They were calibrated in the standard neutron and gamma sources at National Standards Laboratory. Annealing procedure is 400°C for 1 hour, 100°C for 2 hours and spontaneously cooling down to the room temperature in a programmable oven. Two-peak method (a kind of glow curve analysis technique) was used to evaluate the TL response corresponding to the neutron and gamma dose. The TLD pairs were placed outside the treatment field at the neutron-gamma mixed field with 190-MeV proton beam produced by the wobbling system through the polyethylene plate phantom. The results of TLD measurement were compared to the Monte Carlo simulation. Results: The initial experiment results of calculated dose equivalents are 0.63, 0.38, 0.21 and 0.13 mSv per Gy outside the field at the distance of 50, 100, 150 and 200 cm. Conclusion: The TLD-600 and TLD-700 pairs are convenient to estimate neutron and gamma dosimetry during proton therapy. However, an accurate and suitable glow curve analysis technique is necessary. During the wobbling system proton therapy, our results showed that the neutron and gamma doses outside the treatment field are noticeable. This study was supported by the grants from the Chang Gung Memorial Hospital (CMRPD1C0682)

  18. Mining Specifications: A Roadmap

    NASA Astrophysics Data System (ADS)

    Zeller, Andreas

    Recent advances in software validation and verification make it possible to widely automate whether a specification is satisfied. This progress is hampered, though, by the persistent difficulty of writing specifications. Are we facing a “specification crisis”? In this paper, I show how to alleviate the burden of writing specifications by reusing and extending specifications as mined from existing software and give an overview on the state of the art in specification mining, its origins, and its potential.

  19. Application specific serial arithmetic arrays

    NASA Technical Reports Server (NTRS)

    Winters, K.; Mathews, D.; Thompson, T.

    1990-01-01

    High performance systolic arrays of serial-parallel multiplier elements may be rapidly constructed for specific applications by applying hardware description language techniques to a library of full-custom CMOS building blocks. Single clock pre-charged circuits have been implemented for these arrays at clock rates in excess of 100 Mhz using economical 2-micron (minimum feature size) CMOS processes, which may be quickly configured for a variety of applications. A number of application-specific arrays are presented, including a 2-D convolver for image processing, an integer polynomial solver, and a finite-field polynomial solver.

  20. Field emission chemical sensor

    DOEpatents

    Panitz, J.A.

    1983-11-22

    A field emission chemical sensor for specific detection of a chemical entity in a sample includes a closed chamber enclosing two field emission electrode sets, each field emission electrode set comprising (a) an electron emitter electrode from which field emission electrons can be emitted when an effective voltage is connected to the electrode set; and (b) a collector electrode which will capture said electrons emitted from said emitter electrode. One of the electrode sets is passive to the chemical entity and the other is active thereto and has an active emitter electrode which will bind the chemical entity when contacted therewith.

  1. ADANS database specification

    SciTech Connect

    1997-01-16

    The purpose of the Air Mobility Command (AMC) Deployment Analysis System (ADANS) Database Specification (DS) is to describe the database organization and storage allocation and to provide the detailed data model of the physical design and information necessary for the construction of the parts of the database (e.g., tables, indexes, rules, defaults). The DS includes entity relationship diagrams, table and field definitions, reports on other database objects, and a description of the ADANS data dictionary. ADANS is the automated system used by Headquarters AMC and the Tanker Airlift Control Center (TACC) for airlift planning and scheduling of peacetime and contingency operations as well as for deliberate planning. ADANS also supports planning and scheduling of Air Refueling Events by the TACC and the unit-level tanker schedulers. ADANS receives input in the form of movement requirements and air refueling requests. It provides a suite of tools for planners to manipulate these requirements/requests against mobility assets and to develop, analyze, and distribute schedules. Analysis tools are provided for assessing the products of the scheduling subsystems, and editing capabilities support the refinement of schedules. A reporting capability provides formatted screen, print, and/or file outputs of various standard reports. An interface subsystem handles message traffic to and from external systems. The database is an integral part of the functionality summarized above.

  2. P-Channel Lateral Double-Diffused Metal-Oxide-Semiconductor Field-Effect Transistor with Split N-Type Buried Layer for High Breakdown Voltage and Low Specific On-Resistance

    NASA Astrophysics Data System (ADS)

    Liaw, Chorng-Wei; Chang, Ching-Hung; Lin, Ming-Jang; King, Ya-Ching; Hsu, Charles Ching-Hsiang; Lin, Chrong Jung

    2007-07-01

    Many high voltage complementary metal-oxide-semiconductor (HV-CMOS) processes are modified from a standard 5 V CMOS process by adding an N-type heavily doped layer under the P-well of a HV-PMOS drain terminal to isolate a high voltage P-well from a grounded P-substrate. The limitation of breakdown voltage is dominated by P-well concentration and junction depth. For designing a certain breakdown voltage (\\mathit{BV}dss) for a HV-PMOS, the original 5 V CMOS P-well concentration should be decreased, which could degrade 5 V CMOS characteristics, such as NMOS punch through and latch-up immunity. In this study, we demonstrate a novel HV-PMOS based on a split N-type buried layer (NBL), which provides a high \\mathit{BV}dss in a HV-CMOS process. The newly proposed device with NBL split under the P-well of a drain electrode increases \\mathit{BV}dss without degrading specific on-resistance (Ron,sp) and any added process complexity. From this result, P-well concentration could be increased to improve both 5 V NMOS characteristics and HV-PMOS Ron,sp.

  3. Site Specific Evaluation of Multisensor Capacitance Probes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multisensor capacitance probes (MCPs) are widely used for measuring soil water content (SWC) at the field scale. Although manufacturers supply a generic MCP calibration, many researchers recognize that MCPs should be calibrated for specific field conditions. MCPs measurements are typically associa...

  4. Urine specific gravity test

    MedlinePlus

    Urine specific gravity is a laboratory test that shows the concentration of all chemical particles in the urine. ... changes to will tell the provider the specific gravity of your urine. The dipstick test gives only ...

  5. Urine specific gravity test

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/003587.htm Urine specific gravity test To use the sharing features on this page, please enable JavaScript. Urine specific gravity is a laboratory test that shows the concentration ...

  6. On task and theory specificity.

    PubMed

    Newell, K M

    1989-03-01

    One of the significant limitations of the motor control and skill acquisition domain is that the theories, models, and hypotheses are, in most cases, task specific. Many lines of theorizing fail to hold up under even small changes in task constraints, although clearly the field does have some robust phenomena. It is proposed that a broader consideration of the role of task constraints, which is grounded in the methodology of nonlinear dynamics, may help to formulate a more general action theory of coordination and control. PMID:15117675

  7. High electric field phenomena in insulation

    NASA Astrophysics Data System (ADS)

    Laghari, J. R.; Sarjeant, W. J.

    1989-01-01

    The present study extends previous work to include electron radiation-induced changes in monoisopropyl biphenyl (MIPB)-impregnated polypropylene film as well as the effects of neutron/gamma radiation on dry polypropylene films. Effects that were quite similar were induced by both electron and neutron radiation on the properties of interest of the polypropylene films. Impregnation of the film with MIPB had a mitigatory effect on the degradation of the properties. This report also contains the results of a simultaneous electrical and thermal aging study of a capacitor-grade polypropylene film. The data obtained in this study was fitted to models that will enable realistic prediction of lifetimes under operating conditions.

  8. Improved technical specifications

    SciTech Connect

    Hoffman, D.R.

    1994-12-31

    Improved technical specifications for nuclear power plants are outlined. The objectives of this work are to improve safety, provide a clearer understanding of safety significance, and ease NRC and industry administrative burdens. Line item improvements, bases, and implementation of the specifications are discussed.

  9. Prototype Facility Educational Specifications.

    ERIC Educational Resources Information Center

    Idaho State Div. of Professional-Technical Education, Boise.

    This document presents prototypical educational specifications to guide the building and renovation of Idaho vocational schools so they can help communities meet the advanced, professional-technical programs of the future. The specifications start with points to consider when determining school site suitability. The document then sets forth…

  10. Specific Genetic Disorders

    MedlinePlus

    ... of Genetic Terms Definitions for genetic terms Specific Genetic Disorders Many human diseases have a genetic component. ... Condition in an Adult The Undiagnosed Diseases Program Genetic Disorders Achondroplasia Alpha-1 Antitrypsin Deficiency Antiphospholipid Syndrome ...

  11. VOST charcoal specification study

    SciTech Connect

    Foster, A.L.; Bursey, J.T.

    1995-07-01

    The volatile organic sampling train, SW-846 Method 0030, (VOST) is currently one of the leading methodology`s available for the sampling and analysis of volatile organic hazardous compounds from stationary sources at very low levels. The method does not identify a specific equivalent sorbent, nor the performance specifications which would allow determination of an equivalent. Lot 104 petroleum-based charcoal is no longer commercially available. Laboratories are presently using a wide range of substitutes with varying performance from batch to batch of charcoal. To provide performance specifications and identify a replacement for SKC Lot 104 charcoal, a VOST charcoal specification study was initiated. Performance, cost, ease of handling, and plentiful supply make Anasorb 747 a good choice for replacement of SKX Lot 104.

  12. Phobia - simple/specific

    MedlinePlus

    ... person may feel extremely anxious or has a panic attack when exposed to the object of fear. Specific ... behavioral therapy, including learning to recognize and replace ... include: Getting regular exercise Getting enough sleep Reducing ...

  13. Harmonization of Biodiesel Specifications

    SciTech Connect

    Alleman, T. L.

    2008-02-01

    Worldwide biodiesel production has grown dramatically over the last several years. Biodiesel standards vary across countries and regions, and there is a call for harmonization. For harmonization to become a reality, standards have to be adapted to cover all feedstocks. Additionally, all feedstocks cannot meet all specifications, so harmonization will require standards to either tighten or relax. For harmonization to succeed, the biodiesel market must be expanded with the alignment of test methods and specification limits, not contracted.

  14. Multivalued Fields

    SciTech Connect

    Kleinert, Hagen

    2008-01-03

    The lecture gives a short introduction to the theory of multivalued fields which are important for understanding the behavior and phase transitions of many physical systems, such as superfluids, superconductors, crystals, and confined charges.

  15. Field Campaign Guidelines (ARM Climate Research Facility)

    SciTech Connect

    Voyles, JW

    2011-01-17

    The purpose of this document is to establish a common set of guidelines for the Atmospheric Radiation Measurement (ARM) Climate Research Facility for planning, executing, and closing out field campaigns. The steps that guide individual field campaigns are described in the Field Campaign Tracking database tool and are tailored to meet the scope of each specific field campaign.

  16. GMSEC Interface Specification Document 2016 March

    NASA Technical Reports Server (NTRS)

    Handy, Matthew

    2016-01-01

    The GMSEC Interface Specification Document contains the standard set of defined messages. Each GMSEC standard message contains a GMSEC Information Bus Header section and a Message Contents section. Each message section identifies required fields, optional fields, data type and recommended use of the fields. Additionally, this document includes the message subjects associated with the standard messages. The system design of the operations center should ensure the components that are selected use both the API and the defined standard messages in order to achieve full interoperability from component to component.

  17. Lidar base specification

    USGS Publications Warehouse

    Heidemann, Hans Karl.

    2012-01-01

    Lidar is a fast evolving technology, and much has changed in the industry since the final draft of the “Lidar Base Specification Version 1.0” was written. Lidar data have improved in accuracy and spatial resolution, geospatial accuracy standards have been revised by the American Society for Photogrammetry and Remote Sensing (ASPRS), industry standard file formats have been expanded, additional applications for lidar have become accepted, and the need for interoperable data across collections has been realized. This revision to the “Lidar Base Specification Version 1.0” publication addresses those changes and provides continued guidance towards a nationally consistent lidar dataset.

  18. Screening for Specific Phobias

    MedlinePlus

    ... Screening for Posttraumatic Stress Disorder (PTSD) Screening for Social Anxiety Disorder Screening for Specific Phobias Screening for an Anxiety Disorder: Children Screening for an Anxiety Disorder: Family Member Self-Help Strategies: Webinars to Calm Anxious Minds "Triumph" E-News ...

  19. Task-specific Dystonias

    PubMed Central

    Torres-Russotto, Diego; Perlmutter, Joel S.

    2009-01-01

    Task-specific dystonias are primary focal dystonias characterized by excessive muscle contractions producing abnormal postures during selective motor activities that often involve highly skilled, repetitive movements. Historically these peculiar postures were considered psychogenic but have now been classified as forms of dystonia. Writer’s cramp is the most commonly identified task-specific dystonia and has features typical of this group of disorders. Symptoms may begin with lack of dexterity during performance of a specific motor task with increasingly abnormal posturing of the involved body part as motor activity continues. Initially, the dystonia may manifest only during the performance of the inciting task, but as the condition progresses it may also occur during other activities or even at rest. Neurological exam is usually unremarkable except for the dystonia-related abnormalities. Although the precise pathophysiology remains unclear, increasing evidence suggests reduced inhibition at different levels of the sensorimotor system. Symptomatic treatment options include oral medications, botulinum toxin injections, neurosurgical procedures, and adaptive strategies. Prognosis may vary depending upon body part involved and specific type of task affected. Further research may reveal new insights into the etiology, pathophysiology, natural history, and improved treatment of these conditions. PMID:18990127

  20. Component-specific modeling

    NASA Technical Reports Server (NTRS)

    Hirschbein, M. S.

    1982-01-01

    The ability to accurately structurally analyze engine components to assure that they can survive for their designed lifetime in an increasingly harsh environment is discussed. Under the HOST (HOt Section Technology) program, advanced component-specific modeling methods, with built-in analysis capability, will be developed separately for burner liners, turbine blades and vanes. These modeling methods will make maximum use of, but will not rely solely on, existing analysis methods and techniques, to analyze the three identified components. Nor will the complete structural analysis of a component necessarily be performed as a single analysis. The approach to be taken will develop complete software analysis packages with internal, component-specific, self-adaptive solution strategies. Each package will contain a set of modeling and analysis tools. The selection and order of specific methods and techniques within the set to be applied will depend on the specific-component, the current thermo-mechanical loading, and the current state of the component. All modeling and analysis decisions will be made internally based on developed decision criteria within the solution strategies; minimal user intervention will be required.

  1. IDC System Specification Document.

    SciTech Connect

    Clifford, David J.

    2014-12-01

    This document contains the system specifications derived to satisfy the system requirements found in the IDC System Requirements Document for the IDC Reengineering Phase 2 project. Revisions Version Date Author/Team Revision Description Authorized by V1.0 12/2014 IDC Reengineering Project Team Initial delivery M. Harris

  2. Arun field

    SciTech Connect

    Jordan, C.F. Jr.; Abdullah, M.

    1988-01-01

    The Arun field is a giant gas-condensate field operated by Mobil and Pertamina with over 20,000 acres of closure at the top of the Arun reservoir. A middle-shelf patch reef complex of early to middle Miocene age is the producing facies at the Arun field. About 1,100 ft of porous limestones, encased in shales, create a stratigraphic trap for overpressure hydrocarbons. Three main carbonate lithologies were encountered during the examination of over 4,300 ft of core; (1) a reef facies consisting of vuggy, coral encrusting, red-algal boundstones, (2) a near-reef facies consisting of foraminiferal, mixed-skeletal packstones with gravel-size coral fragments, and (3) an interreef lagoonal facies consisting of benthonic-foram packstones. Twenty-two species of corals have been identified from Arun reef facies; major reef-forming coals, listed in order of decreasing abundance, are Porites cf P. Lutes, Cyphastrea microphthalma, Astreopora myriophthalma, Styloconiella gunetheri, Porites solida, and Acropora ssp. The Arun reef is comprised of limestones (with minor amounts of dolomite). No shale beds occur in the sequence, and all carbonate facies are in communication. A pervasive microporosity, occurring throughout the Arun Limestone, results from meteoric alteration of original carbonate mud to form a microrhombic porosity that accounts for about three-fourths of the field's total porosity.

  3. [Pregnancy-specific dermatoses].

    PubMed

    Soutou, B; Aractingi, S

    2015-03-01

    Pregnancy-specific dermatoses include polymorphic eruption of pregnancy, atopic eczema of pregnancy, and pemphigoid gestationis. Intrahepatic cholestasis of pregnancy and impetigo herpetiformis are not real pregnancy-specific dermatoses but they are important to know considering the fetal and maternal risks. Polymorphic eruption of pregnancy is a pruritic disease that usually occurs in primiparous women during the last trimester of pregnancy. Atopic eczema of pregnancy is still controversial as an entity covering conditions with eczematous lesions, prurigo, or folliculitis, and inconstantly associated with a personal history of atopy. Skin biopsy with direct immunofluorescence or search for serum anti-BPAg1 (180kD) NC16a antibodies is mandatory in pruritic dermatoses of pregnancy in order to rule out pemphigoid gestationis. Serum bile salts levels should be tested whenever a generalized pruritus develops during pregnancy in order to rule out intrahepatic cholestasis. PMID:25194221

  4. SPECIFIC HEAT INDICATOR

    DOEpatents

    Horn, F.L.; Binns, J.E.

    1961-05-01

    Apparatus for continuously and automatically measuring and computing the specific heat of a flowing solution is described. The invention provides for the continuous measurement of all the parameters required for the mathematical solution of this characteristic. The parameters are converted to logarithmic functions which are added and subtracted in accordance with the solution and a null-seeking servo reduces errors due to changing voltage drops to a minimum. Logarithmic potentiometers are utilized in a unique manner to accomplish these results.

  5. NOSS altimeter algorithm specifications

    NASA Technical Reports Server (NTRS)

    Hancock, D. W.; Forsythe, R. G.; Mcmillan, J. D.

    1982-01-01

    A description of all algorithms required for altimeter processing is given. Each description includes title, description, inputs/outputs, general algebraic sequences and data volume. All required input/output data files are described and the computer resources required for the entire altimeter processing system were estimated. The majority of the data processing requirements for any radar altimeter of the Seasat-1 type are scoped. Additions and deletions could be made for the specific altimeter products required by other projects.

  6. On field line resonances of hydromagnetic Alfven waves in dipole magnetic field

    SciTech Connect

    Chen, Liu; Cowley, S.C. )

    1989-08-01

    Using the dipole magnetic field model, the authors have developed the theory of field line resonances of hydromagnetic Alfven waves in general magnetic field geometries. In this model, the Alfven speed thus varies both perpendicular and parallel to the magnetic field. Specifically, it is found that field line resonances do persist in the dipole model. The corresponding singular solutions near the resonant field lines as well as the natural definition of standing shear Alfven eigenfunctions have also been systematically derived.

  7. On field line resonances of hydromagnetic Alfven waves in dipole magnetic field

    SciTech Connect

    Chen, Liu; Cowley, S.C.

    1989-07-01

    Using the dipole magnetic field model, we have developed the theory of field line resonances of hydromagnetic Alfven waves in general magnetic field geometries. In this model, the Alfven speed thus varies both perpendicular and parallel to the magnetic field. Specifically, it is found that field line resonances do persist in the dipole model. The corresponding singular solutions near the resonant field lines as well as the natural definition of standing shear Alfven eigenfunctions have also been systematically derived. 11 refs.

  8. Data specifications for INSPIRE

    NASA Astrophysics Data System (ADS)

    Portele, Clemens; Woolf, Andrew; Cox, Simon

    2010-05-01

    In Europe a major recent development has been the entering in force of the INSPIRE Directive in May 2007, establishing an infrastructure for spatial information in Europe to support Community environmental policies, and policies or activities which may have an impact on the environment. INSPIRE is based on the infrastructures for spatial information established and operated by the 27 Member States of the European Union. The Directive addresses 34 spatial data themes needed for environmental applications, with key components specified through technical implementing rules. This makes INSPIRE a unique example of a legislative "regional" approach. One of the requirements of the INSPIRE Directive is to make existing spatial data sets with relevance for one of the spatial data themes available in an interoperable way, i.e. where the spatial data from different sources in Europe can be combined to a coherent result. Since INSPIRE covers a wide range of spatial data themes, the first step has been the development of a modelling framework that provides a common foundation for all themes. This framework is largely based on the ISO 19100 series of standards. The use of common generic spatial modelling concepts across all themes is an important enabler for interoperability. As a second step, data specifications for the first set of themes has been developed based on the modelling framework. The themes include addresses, transport networks, protected sites, hydrography, administrative areas and others. The data specifications were developed by selected experts nominated by stakeholders from all over Europe. For each theme a working group was established in early 2008 working on their specific theme and collaborating with the other working groups on cross-theme issues. After a public review of the draft specifications starting in December 2008, an open testing process and thorough comment resolution process, the draft technical implementing rules for these themes have been

  9. Component-specific modeling

    NASA Technical Reports Server (NTRS)

    Mcknight, R. L.

    1985-01-01

    Accomplishments are described for the second year effort of a 3-year program to develop methodology for component specific modeling of aircraft engine hot section components (turbine blades, turbine vanes, and burner liners). These accomplishments include: (1) engine thermodynamic and mission models; (2) geometry model generators; (3) remeshing; (4) specialty 3-D inelastic stuctural analysis; (5) computationally efficient solvers, (6) adaptive solution strategies; (7) engine performance parameters/component response variables decomposition and synthesis; (8) integrated software architecture and development, and (9) validation cases for software developed.

  10. Specifications Physiological Monitoring System

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The operation of a physiological monitoring system (PMS) is described. Specifications were established for performance, design, interface, and test requirements. The PMS is a compact, microprocessor-based system, which can be worn in a pack on the body or may be mounted on a Spacelab rack or other appropriate structure. It consists of two modules, the Data Control Unit (DCU) and the Remote Control/Display Unit (RCDU). Its purpose is to collect and distribute data from physiological experiments in the Spacelab and in the Orbiter.

  11. Master Software Requirements Specification

    NASA Technical Reports Server (NTRS)

    Hu, Chaumin

    2003-01-01

    A basic function of a computational grid such as the NASA Information Power Grid (IPG) is to allow users to execute applications on remote computer systems. The Globus Resource Allocation Manager (GRAM) provides this functionality in the IPG and many other grids at this time. While the functionality provided by GRAM clients is adequate, GRAM does not support useful features such as staging several sets of files, running more than one executable in a single job submission, and maintaining historical information about execution operations. This specification is intended to provide the environmental and software functional requirements for the IPG Job Manager V2.0 being developed by AMTI for NASA.

  12. Specific construction tests

    NASA Technical Reports Server (NTRS)

    Mcrae, W. V., Jr.

    1980-01-01

    The technical feasibility of the Satellite Power System (SPS) is discussed. The development of feasible operational concepts and conceptualization of specific construction tasks are examined. The logic flow of functional analyses of both the rectenna and the satellite is illustrated. Constraints placed upon the construction processes and equipment by the satellite design are outlined. The construction tasks, when defined and combined into an integrated schedule establish, a time line for construction mass flow demands to be satisfied by the space transportation systems. An example of satellite constructive demands and HLLV delivery capabilities is given.

  13. 310 Facility chemical specifications

    SciTech Connect

    Hagerty, K.J.

    1997-05-21

    The 300 area Treated Effluent Disposal Facility (TEDF) was designed and built to treat the waste water from the 300 area process sewer system. Several treatment technologies are employed to remove the trace quantities of contaminants in the stream, including iron coprecipitation, clarification, filtration, ion exchange, and ultra violet light/hydrogen peroxide oxidation of organics. The chemicals that will be utilized in the treatment process are hydrogen peroxide, sulfuric acid, sodium hydroxide, and ferric chloride. This document annotates the required chemical characteristics of TEDF bulk chemicals as well as the criteria that were used to establish these criteria. The chemical specifications in appendix B are generated from this information.

  14. General Environmental Verification Specification

    NASA Technical Reports Server (NTRS)

    Milne, J. Scott, Jr.; Kaufman, Daniel S.

    2003-01-01

    The NASA Goddard Space Flight Center s General Environmental Verification Specification (GEVS) for STS and ELV Payloads, Subsystems, and Components is currently being revised based on lessons learned from GSFC engineering and flight assurance. The GEVS has been used by Goddard flight projects for the past 17 years as a baseline from which to tailor their environmental test programs. A summary of the requirements and updates are presented along with the rationale behind the changes. The major test areas covered by the GEVS include mechanical, thermal, and EMC, as well as more general requirements for planning, tracking of the verification programs.

  15. VOST charcoal specification study

    SciTech Connect

    Fuerst, R.G.; Foster, A.L.; Bursey, J.T.

    1996-12-31

    The volatile organic sampling train (VOST) is currently one the leading methodologies available for the sampling and analysis of volatile principal organic hazardous constituents (POHCs) and products of incomplete combustion (PICs) from stationary sources at very low levels. However, revisions to the original method are necessary to maintain VOST as a viable regulatory tool. To provide performance specifications and identify a replacement for SKC Lot 104 charcoal, a VOST charcoal specification study was initiated. The following carbon-based candidate sorbents were considered: Tenax-GR (a graphitized Tenax); a Petroleum-based Charcoal; Ambersorbe XE-340 (hydrophobic carbonized resin bead); Anasorb 747 (beaded active carbon with very regular pore size); Carbosieve{reg_sign} S-III (carbon molecular sieve); and a Beaded Activated Charcoal (BAC) (with a very regular pore size). The results indicated that Tenax-GR showed significantly poorer performance than the other candidates in preliminary experimental results. Ambersorb did not retain the gaseous volatile organic compounds tested as well as the others and recovery of vinyl chloride was very low at all levels of spiking. Carbosieve was eliminated as a candidate replacement because of cost and handling problems. The petroleum-based charcoal was eliminated because of difficulties in handling a finely-divided powder. The availability of Anasorb 747 proved to be the deciding factor between it and the BAC. Performance, cost, ease of handling, and plentiful supply make Anasorb{reg_sign} 747 a good choice for replacement of SKC Lot 104. 1 tab.

  16. Gauge fields and inflation

    NASA Astrophysics Data System (ADS)

    Maleknejad, A.; Sheikh-Jabbari, M. M.; Soda, J.

    2013-07-01

    The isotropy and homogeneity of the cosmic microwave background (CMB) favors “scalar driven” early Universe inflationary models. However, gauge fields and other non-scalar fields are far more common at all energy scales, in particular at high energies seemingly relevant to inflation models. Hence, in this review we consider the role and consequences, theoretical and observational, that gauge fields can have during the inflationary era. Gauge fields may be turned on in the background during inflation, or may become relevant at the level of cosmic perturbations. There have been two main classes of models with gauge fields in the background, models which show violation of the cosmic no-hair theorem and those which lead to isotropic FLRW cosmology, respecting the cosmic no-hair theorem. Models in which gauge fields are only turned on at the cosmic perturbation level, may source primordial magnetic fields. We also review specific observational features of these models on the CMB and/or the primordial cosmic magnetic fields. Our discussions will be mainly focused on the inflation period, with only a brief discussion on the post inflationary (p)reheating era. Large field models: The initial value of the inflaton field is large, generically super-Planckian, and it rolls slowly down toward the potential minimum at smaller φ values. For instance, chaotic inflation is one of the representative models of this class. The typical potential of large-field models has a monomial form as V(φ)=V0φn. A simple analysis using the dynamical equations reveals that for number of e-folds Ne larger than 60, we require super-Planckian initial field values,5φ0>3M. For these models typically ɛ˜η˜Ne-1. Small field models: Inflaton field is initially small and slowly evolves toward the potential minimum at larger φ values. The small field models are characterized by the following potential V(φ)=V0(1-(), which corresponds to a Taylor expansion about the origin, but more realistic

  17. Broadened diesel fuel specifications for rail applications

    SciTech Connect

    Cataldi, C.R.

    1988-01-01

    As the demand for distillate products increases, petroleum refiners find it increasingly expensive to meet the traditional specifications for jet and diesel fuels. Because those costs eventually show up in the price of fuel, the railroad industry has a diesel fuel research program to identify broadened specification fuels that cost less than standard fuels and which do not adversely affect engine performance or maintenance cost. Laboratory tests concentrated on cetane number, distillation range, and viscosity. The tests included 72 hours at idle speed, engine performance, and 500-hour endurance tests. Long-term field tests have verified the laboratory findings that cetane number can be reduced to 32 and 90 percent distillation point increased to 700/sup 0/F. Several railroads now have over three years of experience with broadened specification fuels in normal operations with no reported problems. With formal tests, some railroads have also relaxed their winter specifications for pour and cloud points.

  18. Specific Impulse Definition for Ablative Laser Propulsion

    NASA Technical Reports Server (NTRS)

    Herren, Kenneth A.; Gregory, Don A.

    2004-01-01

    The term "specific impulse" is so ingrained in the field of rocket propulsion that it is unlikely that any fundamental argument would be taken seriously for its removal. It is not an ideal measure but it does give an indication of the amount of mass flow (mass loss/time), as in fuel rate, required to produce a measured thrust over some time period This investigation explores the implications of being able to accurately measure the ablation rate and how the language used to describe the specific impulse results may have to change slightly, and recasts the specific impulse as something that is not a time average. It is not currently possible to measure the ablation rate accurately in real time so it is generally just assumed that a constant amount of material will be removed for each laser pulse delivered The specific impulse dependence on the ablation rate is determined here as a correction to the classical textbook definition.

  19. Gauge fields and inflation

    NASA Astrophysics Data System (ADS)

    Maleknejad, A.; Sheikh-Jabbari, M. M.; Soda, J.

    2013-07-01

    The isotropy and homogeneity of the cosmic microwave background (CMB) favors “scalar driven” early Universe inflationary models. However, gauge fields and other non-scalar fields are far more common at all energy scales, in particular at high energies seemingly relevant to inflation models. Hence, in this review we consider the role and consequences, theoretical and observational, that gauge fields can have during the inflationary era. Gauge fields may be turned on in the background during inflation, or may become relevant at the level of cosmic perturbations. There have been two main classes of models with gauge fields in the background, models which show violation of the cosmic no-hair theorem and those which lead to isotropic FLRW cosmology, respecting the cosmic no-hair theorem. Models in which gauge fields are only turned on at the cosmic perturbation level, may source primordial magnetic fields. We also review specific observational features of these models on the CMB and/or the primordial cosmic magnetic fields. Our discussions will be mainly focused on the inflation period, with only a brief discussion on the post inflationary (p)reheating era. Large field models: The initial value of the inflaton field is large, generically super-Planckian, and it rolls slowly down toward the potential minimum at smaller φ values. For instance, chaotic inflation is one of the representative models of this class. The typical potential of large-field models has a monomial form as V(φ)=V0φn. A simple analysis using the dynamical equations reveals that for number of e-folds Ne larger than 60, we require super-Planckian initial field values,5φ0>3M. For these models typically ɛ˜η˜Ne-1. Small field models: Inflaton field is initially small and slowly evolves toward the potential minimum at larger φ values. The small field models are characterized by the following potential V(φ)=V0(1-(), which corresponds to a Taylor expansion about the origin, but more realistic

  20. A specific hygiene hypothesis.

    PubMed

    Shunsheng Han, Cliff

    2016-08-01

    Allergic diseases have reached epidemic proportions in Western populations in the last several decades. The hygiene hypothesis proposed more than twenty years ago has helped us to understand the epidemic and has been verified with numerous studies. However, translational measures deduced from these studies to prevent allergic diseases have not proven effective. Recent studies on immigrants' allergies and any potential association between oral infection and allergic diseases prompt me to propose a specific hygiene hypothesis to explain how oral hygiene practices might have contributed to the uprising of hay fever, the most common allergic disease. The historic oral hygiene level in US is closely associated with the emerging allergic epidemic. Future studies to test the hypothesis are needed and verification of the hypothesis can potentially yield highly effective measures to prevent allergic diseases. PMID:27372876

  1. Cylinder Test Specification

    SciTech Connect

    Richard Catanach; Larry Hill; Herbert Harry; Ernest Aragon; Don Murk

    1999-10-01

    The purpose of the cylinder testis two-fold: (1) to characterize the metal-pushing ability of an explosive relative to that of other explosives as evaluated by the E{sub 19} cylinder energy and the G{sub 19} Gurney energy and (2) to help establish the explosive product equation-of-state (historically, the Jones-Wilkins-Lee (JWL) equation). This specification details the material requirements and procedures necessary to assemble and fire a typical Los Alamos National Laboratory (LANL) cylinder test. Strict adherence to the cylinder. material properties, machining tolerances, material heat-treatment and etching processes, and high explosive machining tolerances is essential for test-to-test consistency and to maximize radial wall expansions. Assembly and setup of the cylinder test require precise attention to detail, especially when placing intricate pin wires on the cylinder wall. The cylinder test is typically fired outdoors and at ambient temperature.

  2. Site-specific photochemistry

    NASA Astrophysics Data System (ADS)

    Koplitz, Brent D.; Brum, Jeffrey L.; Deshmukh, Subhash; Xu, Xiaodong; Wang, Zhongrui; Yen, Yu-Fong

    1992-04-01

    We present results on `site-specific' H-atom production in photolysis experiments conducted under collisionless conditions. H and D atoms are used as labels to investigate the site(s) at which C-H (or C-D) bond cleavage occurs in a variety of haloalkane systems. Experiments using two photolysis lasers clearly indicate that photon absorption by an intermediate, presumably an alkyl radical, is important in many of the systems studied. The site(s) (e.g., (alpha) , (beta) , or (gamma) ) at which C-H (or C-D) bond cleavage occurs is dependent not only on the nature of the molecule, but also on the photolysis wavelength. As a diagnostic tool, H- and D-atom Doppler spectroscopy allows us to gain insight into the energetics associated with the various dissociation processes. Our overall aim is to gain a further understanding of the photolysis properties of a variety of simple molecules and their associated radicals.

  3. Current progress in patient-specific modeling

    PubMed Central

    2010-01-01

    We present a survey of recent advancements in the emerging field of patient-specific modeling (PSM). Researchers in this field are currently simulating a wide variety of tissue and organ dynamics to address challenges in various clinical domains. The majority of this research employs three-dimensional, image-based modeling techniques. Recent PSM publications mostly represent feasibility or preliminary validation studies on modeling technologies, and these systems will require further clinical validation and usability testing before they can become a standard of care. We anticipate that with further testing and research, PSM-derived technologies will eventually become valuable, versatile clinical tools. PMID:19955236

  4. LCLS Far-Field Spontaneous Radiation

    Energy Science and Technology Software Center (ESTSC)

    2004-04-16

    This application (FarFieldDisplay) is a tool for displaying and analyzing far-field spontaneous spectral flux data for the Linac Coherent Light Source (LCLS) Calculated by Roman Tatchyn (Stanford University). This tool allows the user to view sliced spatial and energy distributions of the fat-field photons selected for specific energies or positions transverse to the beam axis,

  5. Intent Specifications: An Approach to Building Human-Centered Specifications

    NASA Technical Reports Server (NTRS)

    Leveson, Nancy G.

    1999-01-01

    This paper examines and proposes an approach to writing software specifications, based on research in systems theory, cognitive psychology, and human-machine interaction. The goal is to provide specifications that support human problem solving and the tasks that humans must perform in software development and evolution. A type of specification, called intent specifications, is constructed upon this underlying foundation.

  6. Microbial field pilot study

    SciTech Connect

    Knapp, R.M.; McInerney, M.J.; Menzie, D.E.; Coates, J.D.; Chisholm, J.L.

    1993-05-01

    A multi-well microbially enhanced oil recovery field pilot has been performed in the Southeast Vassar Vertz Sand Unit in Payne County, Oklahoma. The primary emphasis of the experiment was preferential plugging of high permeability zones for the purpose of improving waterflood sweep efficiency. Studies were performed to determine reservoir chemistry, ecology, and indigenous bacteria populations. Growth experiments were used to select a nutrient system compatible with the reservoir that encouraged growth of a group of indigenous nitrate-using bacteria and inhibit growth of sulfate-reducing bacteria. A specific field pilot area behind an active line drive waterflood was selected. Surface facilities were designed and installed. Injection protocols of bulk nutrient materials were prepared to facilitate uniform distribution of nutrients within the pilot area. By the end of December, 1991, 82.5 tons (75.0 tonnes) of nutrients had been injected in the field. A tracer test identified significant heterogeneity in the SEVVSU and made it necessary to monitor additional production wells in the field. The tracer tests and changes in production behavior indicate the additional production wells monitored during the field trial were also affected. Eighty two and one half barrels (13.1 m[sup 3]) of tertiary oil have been recovered. Microbial activity has increased CO[sub 2] content as indicated by increased alkalinity. A temporary rise in sulfide concentration was experienced. These indicate an active microbial community was generated in the field by the nutrient injection. Pilot area interwell pressure interference test results showed that significant permeability reduction occurred. The interwell permeabilities in the pilot area between the injector and the three pilot production wells were made more uniform which indicates a successful preferential plugging enhanced oil recovery project.

  7. Quantum field tomography

    NASA Astrophysics Data System (ADS)

    Steffens, A.; Riofrío, C. A.; Hübener, R.; Eisert, J.

    2014-12-01

    We introduce the concept of quantum field tomography, the efficient and reliable reconstruction of unknown quantum fields based on data of correlation functions. At the basis of the analysis is the concept of continuous matrix product states (cMPS), a complete set of variational states grasping states in one-dimensional quantum field theory. We innovate a practical method, making use of and developing tools in estimation theory used in the context of compressed sensing such as Prony methods and matrix pencils, allowing us to faithfully reconstruct quantum field states based on low-order correlation functions. In the absence of a phase reference, we highlight how specific higher order correlation functions can still be predicted. We exemplify the functioning of the approach by reconstructing randomized cMPS from their correlation data and study the robustness of the reconstruction for different noise models. Furthermore, we apply the method to data generated by simulations based on cMPS and using the time-dependent variational principle. The presented approach is expected to open up a new window into experimentally studying continuous quantum systems, such as those encountered in experiments with ultra-cold atoms on top of atom chips. By virtue of the analogy with the input-output formalism in quantum optics, it also allows for studying open quantum systems.

  8. Specific language impairment.

    PubMed

    Kamhi, Alan G; Clark, Mary Kristen

    2013-01-01

    The acquisition of language is one of the most important achievements in young children, in part because most children appear to acquire language with little effort. Some children are not so fortunate, however. There is a large group of children who also have difficulty learning language, but do not have obvious neurological, cognitive, sensory, emotional, or environmental deficits. Clinicians often refer to these children as language disordered or language impaired. Researchers tend to refer to these children as specific language impaired (SLI). Children with SLI have intrigued researchers for many years because there is no obvious reason for their language learning difficulties. SLI has been found to be an enduring condition that begins in early childhood and often persists into adolescence and adulthood. The language problems of children with SLI are not limited to spoken language; they also affect reading and writing and thus much of academic learning. Knowledge of the characteristics of SLI should aid physicians, pediatricians, and early childhood specialists to identify these children during the preschool years and ensure that they receive appropriate services. With high-quality language intervention and literacy instruction, most children with SLI should be able to perform and function adequately in school and beyond. PMID:23622167

  9. Genotype Specification Language.

    PubMed

    Wilson, Erin H; Sagawa, Shiori; Weis, James W; Schubert, Max G; Bissell, Michael; Hawthorne, Brian; Reeves, Christopher D; Dean, Jed; Platt, Darren

    2016-06-17

    We describe here the Genotype Specification Language (GSL), a language that facilitates the rapid design of large and complex DNA constructs used to engineer genomes. The GSL compiler implements a high-level language based on traditional genetic notation, as well as a set of low-level DNA manipulation primitives. The language allows facile incorporation of parts from a library of cloned DNA constructs and from the "natural" library of parts in fully sequenced and annotated genomes. GSL was designed to engage genetic engineers in their native language while providing a framework for higher level abstract tooling. To this end we define four language levels, Level 0 (literal DNA sequence) through Level 3, with increasing abstraction of part selection and construction paths. GSL targets an intermediate language based on DNA slices that translates efficiently into a wide range of final output formats, such as FASTA and GenBank, and includes formats that specify instructions and materials such as oligonucleotide primers to allow the physical construction of the GSL designs by individual strain engineers or an automated DNA assembly core facility. PMID:26886161

  10. Conceptual design of stacked-layer detectors to increase the sensitivity of Fast Neutron Gamma-ray Radiography (FNGR)

    NASA Astrophysics Data System (ADS)

    Cho, Jea Hyung; Kim, Kwang Hyun; Chung, Young Hyun

    2012-04-01

    This study is focused on the structure and other possible factors related to scintillators used in the Fast Neutron and Gamma-ray Radiography (FNGR) system to increase its sensitivity. The CsI(Tl) crystal scintillator (Co-60 gamma-ray detection) and the BC430 plastic scintillator (14 MeV fast neutron detection) were analyzed with the Monte Carlo simulation (MCNPX and DETEC97 codes). Each scintillator was investigated with regard to the optimum thickness (1 cm × 1 cm), reconfiguration of detector modules (a stacked-layer structure), the optimum surface treatment, and the spectral matching with customized PIN-type photodiodes. As a result, the optimum thickness of the CsI(Tl) was found to be 4.5 cm; the optimum value was 5.5 cm for the BC430. When the detector modules were stacked in a sandwich structure rather than the existing single detector structure, the light photon transmission to the surface of the photodiode was enhanced by 40% and 58% for CsI(Tl) and BC430, respectively. In the matter of scintillator surface treatment, both scintillators were simulated with unpolished and polished condition before coating. The polished condition of the scintillator surfaces showed a higher performance, more than doubling that of the unpolished condition surfaces. Then, the performance improvement of the scintillator with the paint coating was compared to the scintillator with the metal coating conditions. For CsI(Tl), the metal coating showed a 10 % higher performance than that of the paint coating, and the metal coating of BC430 showed a 6% higher performance than that of the paint coating. As a result of spectral matching between the scintillators and the customized PIN-photodiodes, PS100-6b of Silicon AG, SD445-14-21-305 of API, and FSD1010-CAL of THOLABS were compared. The spectral matching factor of PS100-6b was 0.39 with CsI(Tl) and was 0.42 with BC430; the spectral matching factors of the other samples were relatively lower (SD445-14-21-305 with CsI(Tl): 0.29; SD445-14-21-305 with BC430: 0.33; FSD1010-CAL with CsI(Tl): 0.26; FSD1010-CAL with BC430: 0.29).

  11. Effect of fast neutron, gamma-ray and combined radiations on the thermal decomposition of ammonium perchlorate single crystals

    NASA Technical Reports Server (NTRS)

    Herley, P. J.; Wang, C. S.; Varsi, G.; Levy, P. W.

    1974-01-01

    The thermal decomposition kinetics have been determined for ammonium perchlorate crystals subjected to a fast neutron irradiation or to a fast neutron irradiation followed by a gamma-ray irradiation. Qualitatively, the radiation induced changes are similar to those obtained in this and in previous studies, with samples exposed only to gamma rays. The induction period is shortened and the rate constants, obtained from an Avrami-Erofeyev kinetic analysis, are modified. The acceleratory period constant increases and the decay period constant decreases. When compared on an equal deposited energy basis, the fast neutron induced changes are appreciably larger than the gamma-ray induced changes. Some, or all, of the fast neutron induced effects might be attributable to the introduction of localized regions of concentrated radiation damage ('spikes') by lattice atom recoils which become thermal decomposition sites when the crystals are heated.

  12. Learning LM Specificity for Ganglion Cells

    NASA Technical Reports Server (NTRS)

    Ahumada, Albert J.

    2015-01-01

    Unsupervised learning models have been proposed based on experience (Ahumada and Mulligan, 1990;Wachtler, Doi, Lee and Sejnowski, 2007) that allow the cortex to develop units with LM specific color opponent receptive fields like the blob cells reported by Hubel and Wiesel on the basis of visual experience. These models used ganglion cells with LM indiscriminate wiring as inputs to the learning mechanism, which was presumed to occur at the cortical level.

  13. The devil is in the specificity: the negative effect of prediction specificity on prediction accuracy.

    PubMed

    Yoon, Song-Oh; Suk, Kwanho; Goo, Jin Kyung; Lee, Jiheon; Lee, Seon Min

    2013-07-01

    In the research reported here, we proposed and demonstrated the prediction-specificity effect, which states that people's prediction of the general outcome of an event (e.g., the winner of a soccer match) is less accurate when the prediction question is framed in a more specific manner (e.g., guessing the score) rather than in a less specific manner (e.g., guessing the winner). We demonstrated this effect by examining people's predictions on actual sports games both in field and laboratory studies. In Study 1, the analysis of 19 billion bets from a commercial sports-betting business provided evidence for the effect of prediction specificity. This effect was replicated in three controlled laboratory studies, in which participants predicted the outcomes of a series of soccer matches. Furthermore, the negative effect of prediction specificity was mediated by participants' underweighting of important holistic information during decision making. PMID:23660410

  14. An Analytic Approximation to Very High Specific Impulse and Specific Power Interplanetary Space Mission Analysis

    NASA Technical Reports Server (NTRS)

    Williams, Craig Hamilton

    1995-01-01

    A simple, analytic approximation is derived to calculate trip time and performance for propulsion systems of very high specific impulse (50,000 to 200,000 seconds) and very high specific power (10 to 1000 kW/kg) for human interplanetary space missions. The approach assumed field-free space, constant thrust/constant specific power, and near straight line (radial) trajectories between the planets. Closed form, one dimensional equations of motion for two-burn rendezvous and four-burn round trip missions are derived as a function of specific impulse, specific power, and propellant mass ratio. The equations are coupled to an optimizing parameter that maximizes performance and minimizes trip time. Data generated for hypothetical one-way and round trip human missions to Jupiter were found to be within 1% and 6% accuracy of integrated solutions respectively, verifying that for these systems, credible analysis does not require computationally intensive numerical techniques.

  15. Studies in quantum field theory

    NASA Astrophysics Data System (ADS)

    Polmar, S. K.

    The theoretical physics group at Washington University has been devoted to the solution of problems in theoretical and mathematical physics. All of the personnel on this task have a similar approach to their research in that they apply sophisticated analytical and numerical techniques to problems primarily in quantum field theory. Specifically, this group has worked on quantum chromodynamics, classical Yang-Mills fields, chiral symmetry breaking condensates, lattice field theory, strong-coupling approximations, perturbation theory in large order, nonlinear waves, 1/N expansions, quantum solitons, phase transitions, nuclear potentials, and early universe calculations.

  16. USA Track & Field Coaching Manual. USA Track & Field.

    ERIC Educational Resources Information Center

    USA Track and Field, Inc., Indianapolis, IN.

    This book presents comprehensive, ready-to-apply information from 33 world-class coaches and experts about major track and field events for high school and college coaches. The volume features proven predictive testing procedures; detailed event-specific technique instruction; carefully crafted training programs; and preparation and performance…

  17. Field spectroscopy of agricultural crops

    NASA Technical Reports Server (NTRS)

    Bauer, M. E.; Daughtry, C. S. T.; Biehl, L. L.; Kanemasu, E. T.; Hall, F. G.

    1986-01-01

    The development of the full potential of multispectral data acquired from satellites, requires quantitative knowledge, and physical models of the spectral properties of specific earth surface features. Knowledge of the relationships between spectral-radiometric characteristics and important biophysical parameters of agricultural crops and soils can best be obtained by carefully controlled studies of fields or plots. It is important to select plots where data describing the agronomic-biophysical properties of the crop canopies and soil background are attainable, taking into account also the feasibility of frequent timely calibrated spectral measurements. The term 'field spectroscopy' is employed for this research. The present paper is concerned with field research which was sponsored by NASA as part of the AgRISTARS Supporting Research Project. Attention is given to field research objectives, field research instrumentation, measurement procedures, spectral-temporal profile modeling, and the effects of cultural and environmental factors on crop reflectance.

  18. Light field morphing using 2D features.

    PubMed

    Wang, Lifeng; Lin, Stephen; Lee, Seungyong; Guo, Baining; Shum, Heung-Yeung

    2005-01-01

    We present a 2D feature-based technique for morphing 3D objects represented by light fields. Existing light field morphing methods require the user to specify corresponding 3D feature elements to guide morph computation. Since slight errors in 3D specification can lead to significant morphing artifacts, we propose a scheme based on 2D feature elements that is less sensitive to imprecise marking of features. First, 2D features are specified by the user in a number of key views in the source and target light fields. Then the two light fields are warped view by view as guided by the corresponding 2D features. Finally, the two warped light fields are blended together to yield the desired light field morph. Two key issues in light field morphing are feature specification and warping of light field rays. For feature specification, we introduce a user interface for delineating 2D features in key views of a light field, which are automatically interpolated to other views. For ray warping, we describe a 2D technique that accounts for visibility changes and present a comparison to the ideal morphing of light fields. Light field morphing based on 2D features makes it simple to incorporate previous image morphing techniques such as nonuniform blending, as well as to morph between an image and a light field. PMID:15631126

  19. Specification-Based Testing Via Domain Specific Language

    NASA Astrophysics Data System (ADS)

    Sroka, Michal; Nagy, Roman; Fisch, Dominik

    2014-12-01

    The article presents tCF (testCaseFramework) - a domain specific language with corresponding toolchain for specification-based software testing of embedded software. tCF is designed for efficient preparation of maintainable and intelligible test cases and for testing process automation, as it allows to generate platform specific test cases for various testing levels. The article describes the essential parts of the tCF meta-model and the applied concept of platform specific test cases generators.

  20. Evaluating cotton stripper field performance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton strippers are used primarily in the Southern High Plains due to the specific cotton varieties grown. Typically, cotton strippers cost about two-thirds the price of a cotton picker and range from one-half to one-fourth the horsepower. A cotton stripper also has a higher field and harvesting ef...

  1. The Research Base in Languages for Specific Purposes.

    ERIC Educational Resources Information Center

    Grosse, Christine Uber

    More than 200 publications regarding Languages for Specific Purposes (LSP) from the past 25 years, excluding work on English for Specific Purposes, are compiled in this literature review. In introductory comments that precede the bibliography, it is noted that most of the activity in this field has occurred in the last decade, with eight…

  2. Site-specific crop management using geophysical proximal sensors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Key components of site-specific crop management are (i) identifying the site-specific factors that influence within-field crop yield variation and (ii) spatially characterizing those factors. Geo-referenced measurements of apparent soil electrical conductivity (ECa) provide a potential means of cha...

  3. Site-Specific Weed Management: Myth or Magic?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Site-specific weed management (SSWM) is a potential method to reduce the risks of herbicide use on water quality and public health without impacting crop yield. With site-specific weed management, areas of the field are left untreated where control is not economically justified. Where control is nee...

  4. Specificity and non-specificity in RNA–protein interactions

    PubMed Central

    Jankowsky, Eckhard; Harris, Michael E.

    2016-01-01

    Gene expression is regulated by complex networks of interactions between RNAs and proteins. Proteins that interact with RNA have been traditionally viewed as either specific or non-specific; specific proteins interact preferentially with defined RNA sequence or structure motifs, whereas non-specific proteins interact with RNA sites devoid of such characteristics. Recent studies indicate that the binary “specific vs. non-specific” classification is insufficient to describe the full spectrum of RNA–protein interactions. Here, we review new methods that enable quantitative measurements of protein binding to large numbers of RNA variants, and the concepts aimed as describing resulting binding spectra: affinity distributions, comprehensive binding models and free energy landscapes. We discuss how these new methodologies and associated concepts enable work towards inclusive, quantitative models for specific and non-specific RNA–protein interactions. PMID:26285679

  5. Compositional Specification of Software Architecture

    NASA Technical Reports Server (NTRS)

    Penix, John; Lau, Sonie (Technical Monitor)

    1998-01-01

    This paper describes our experience using parameterized algebraic specifications to model properties of software architectures. The goal is to model the decomposition of requirements independent of the style used to implement the architecture. We begin by providing an overview of the role of architecture specification in software development. We then describe how architecture specifications are build up from component and connector specifications and give an overview of insights gained from a case study used to validate the method.

  6. Local Magnetic Field Role in Star Formation

    NASA Astrophysics Data System (ADS)

    Koch, P. M.; Tang, Y. W.; Ho, P. T. P.; Zhang, Q.; Girart, J. M.; Chen, H. R. V.; Lai, S. P.; Li, H. B.; Li, Z. Y.; Liu, H. B.; Padovani, M.; Qiu, K.; Rao, R.; Yen, H. W.; Frau, P.; Chen, H. H.; Ching, T. C.

    2016-05-01

    We highlight distinct and systematic observational features of magnetic field morphologies in polarized submm dust continuum. We illustrate this with specific examples and show statistical trends from a sample of 50 star-forming regions.

  7. Applied-field MPD thruster geometry effects

    NASA Technical Reports Server (NTRS)

    Myers, Roger M.

    1991-01-01

    Eight MPD thruster configurations were used to study the effects of applied field strength, propellant, and facility pressure on thruster performance. Vacuum facility background pressures higher than approx. 0.12 Pa were found to greatly influence thruster performance and electrode power deposition. Thrust efficiency and specific impulse increased monotonically with increasing applied field strength. Both cathode and anode radii fundamentally influenced the efficiency specific impulse relationship, while their lengths influence only the magnitude of the applied magnetic field required to reach a given performance level. At a given specific impulse, large electrode radii result in lower efficiencies for the operating conditions studied. For all test conditions, anode power deposition was the largest efficiency loss, and represented between 50 and 80 pct. of the input power. The fraction of the input power deposited into the anode decreased with increasing applied field and anode radii. The highest performance measured, 20 pct. efficiency at 3700 seconds specific impulse, was obtained using hydrogen propellant.

  8. Chapter A6. Field Measurements

    USGS Publications Warehouse

    Wilde, Franceska D., (Edited By); Radtke, Dean B.

    1998-01-01

    The National Field Manual for the Collection of Water-Quality Data (National Field Manual) provides guidelines and standard procedures for U.S. Geological Survey (USGS) personnel who collect data used to assess the quality of the Nation's surface-water and ground-water resources. Chapter A6 presents procedures and guidelines for the collection of data on air and water temperature, and on dissolved-oxygen concentrations, specific electrical conductance, pH, reduction-oxidation potential, alkalinity, and turbidity in water. Each chapter of the National Field Manual is published separately and revised periodically. Newly published and revised chapters are posted on the World Wide Web on the USGS page 'National Field Manual for the Collection of Water-Quality Data.' The URL for this page is http://pubs.water.usgs.gov/twri9A (accessed August 6, 2005).

  9. Topological properties of microwave magnetoelectric fields.

    PubMed

    Berezin, M; Kamenetskii, E O; Shavit, R

    2014-02-01

    Collective excitations of electron spins in a ferromagnetic sample dominated by the magnetic dipole-dipole interaction strongly influence the field structure of microwave radiation. A small quasi-two-dimensional ferrite disk with magnetic-dipolar-mode (MDM) oscillation spectra can behave as a source of specific fields in vacuum, termed magnetoelectric (ME) fields. A coupling between the time-varying electric and magnetic fields in the ME-field structures is different from such a coupling in regular electromagnetic fields. The ME fields are characterized by strong energy confinement at a subwavelength region of microwave radiation, topologically distinctive power-flow vortices, and helicity parameters [E. O. Kamenetskii, R. Joffe, and R. Shavit, Phys. Rev. E 87, 023201 (2013)]. We study topological properties of microwave ME fields by loading a MDM ferrite particle with different dielectric samples. We establish a close connection between the permittivity parameters of dielectric environment and the topology of ME fields. We show that the topology of ME fields is strongly correlated with the Fano-resonance spectra observed at terminals of a microwave structure. We reveal specific thresholds in the Fano-resonance spectra appearing at certain permittivity parameters of dielectric samples. We show that ME fields originated from MDM ferrite disks can be distinguished by topological portraits of the helicity parameters and can have a torsion degree of freedom. Importantly, the ME-field phenomena can be viewed as implementations of space-time coordinate transformations on waves. PMID:25353595

  10. Internal split field generator

    SciTech Connect

    Thundat; Thomas George; Van Neste, Charles W.; Vass, Arpad Alexander

    2012-01-03

    A generator includes a coil of conductive material. A stationary magnetic field source applies a stationary magnetic field to the coil. An internal magnetic field source is disposed within a cavity of the coil to apply a moving magnetic field to the coil. The stationary magnetic field interacts with the moving magnetic field to generate an electrical energy in the coil.

  11. Quantum interactions between nonperturbative vacuum fields

    SciTech Connect

    Millo, R.; Faccioli, P.; Scorzato, L.

    2010-04-01

    We develop an approach to investigate the nonperturbative dynamics of quantum field theories, in which specific vacuum field fluctuations are treated as the low-energy dynamical degrees of freedom, while all other vacuum field configurations are explicitly integrated out from the path integral. We show how to compute the effective interaction between the vacuum field degrees of freedom both perturbatively (using stochastic perturbation theory) and fully nonperturbatively (using lattice field theory simulations). The present approach holds to all orders in the couplings and does not rely on the semiclassical approximation.

  12. Variola Virus-Specific Diagnostic Assays: Characterization, Sensitivity, and Specificity

    PubMed Central

    Kondas, Ashley V.; Olson, Victoria A.; Li, Yu; Abel, Jason; Laker, Miriam; Rose, Laura; Wilkins, Kimberly; Turner, Jonathan; Kline, Richard

    2015-01-01

    A public health response relies upon rapid and reliable confirmation of disease by diagnostic assays. Here, we detail the design and validation of two variola virus-specific real-time PCR assays, since previous assays cross-reacted with newly identified cowpox viruses. The assay specificity must continually be reassessed as other closely related viruses are identified. PMID:25673790

  13. Production of high specific activity silicon-32

    SciTech Connect

    Phillips, D.R.; Brzezinski, M.A.

    1998-12-31

    This is the final report of a three-year, Laboratory Directed Research and Development Project (LDRD) at Los Alamos National Laboratory (LANL). There were two primary objectives for the work performed under this project. The first was to take advantage of capabilities and facilities at Los Alamos to produce the radionuclide {sup 32}Si in unusually high specific activity. The second was to combine the radioanalytical expertise at Los Alamos with the expertise at the University of California to develop methods for the application of {sup 32}Si in biological oceanographic research related to global climate modeling. The first objective was met by developing targetry for proton spallation production of {sup 32}Si in KCl targets and chemistry for its recovery in very high specific activity. The second objective was met by developing a validated field-useable, radioanalytical technique, based upon gas-flow proportional counting, to measure the dynamics of silicon uptake by naturally occurring diatoms.

  14. Cell-Specific Aptamers as Emerging Therapeutics

    PubMed Central

    Meyer, Cindy; Hahn, Ulrich; Rentmeister, Andrea

    2011-01-01

    Aptamers are short nucleic acids that bind to defined targets with high affinity and specificity. The first aptamers have been selected about two decades ago by an in vitro process named SELEX (systematic evolution of ligands by exponential enrichment). Since then, numerous aptamers with specificities for a variety of targets from small molecules to proteins or even whole cells have been selected. Their applications range from biosensing and diagnostics to therapy and target-oriented drug delivery. More recently, selections using complex targets such as live cells have become feasible. This paper summarizes progress in cell-SELEX techniques and highlights recent developments, particularly in the field of medically relevant aptamers with a focus on therapeutic and drug-delivery applications. PMID:21904667

  15. Current Status of Protein Force Fields for Molecular Dynamics

    PubMed Central

    Lopes, Pedro E.M.; Guvench, Olgun

    2015-01-01

    Summary The current status of classical force fields for proteins is reviewed. These include additive force fields as well as the latest developments in the Drude and AMOEBA polarizable force fields. Parametrization strategies developed specifically for the Drude force field are described and compared with the additive CHARMM36 force field. Results from molecular simulations of proteins and small peptides are summarized to illustrate the performance of the Drude and AMOEBA force fields. PMID:25330958

  16. 7 CFR 1755.3 - Field trials.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Engineering Branch, for review and approval. (j) Procedures for establishing field trials for the various... 7 Agriculture 11 2012-01-01 2012-01-01 false Field trials. 1755.3 Section 1755.3 Agriculture... TELECOMMUNICATIONS POLICIES ON SPECIFICATIONS, ACCEPTABLE MATERIALS, AND STANDARD CONTRACT FORMS § 1755.3...

  17. 7 CFR 1755.3 - Field trials.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Engineering Branch, for review and approval. (j) Procedures for establishing field trials for the various... 7 Agriculture 11 2014-01-01 2014-01-01 false Field trials. 1755.3 Section 1755.3 Agriculture... TELECOMMUNICATIONS POLICIES ON SPECIFICATIONS, ACCEPTABLE MATERIALS, AND STANDARD CONTRACT FORMS § 1755.3...

  18. 7 CFR 1755.3 - Field trials.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Engineering Branch, for review and approval. (j) Procedures for establishing field trials for the various... 7 Agriculture 11 2013-01-01 2013-01-01 false Field trials. 1755.3 Section 1755.3 Agriculture... TELECOMMUNICATIONS POLICIES ON SPECIFICATIONS, ACCEPTABLE MATERIALS, AND STANDARD CONTRACT FORMS § 1755.3...

  19. Teaching Historical Geography in the Field

    ERIC Educational Resources Information Center

    Keighren, Innes M.

    2013-01-01

    This paper examines the pedagogical and practical challenges associated with teaching historical geography, and archival research specifically, in the context of the undergraduate field trip. In so doing, it draws upon students' own reflections on the experience of conducting archival research during a field trip to New York City and presents…

  20. Playing Fields and Hard Surface Areas.

    ERIC Educational Resources Information Center

    Department of Education and Science, London (England).

    Guidelines are presented regarding the planning, layout, construction, and maintenance of outdoor playing fields for physical education. Consideration is given to the dual use of playing fields by the school and the community, the planning of hard surface playing areas, and specifications and bills of quantities. Maintenance costs of grass playing…

  1. Bow-shaped toroidal field coils

    SciTech Connect

    Bonanos, P.

    1981-05-01

    Design features of Bow-Shaped Toroidal Field Coils are described and compared with circular and D shaped coils. The results indicate that bow coils can produce higher field strengths, store more energy and be made demountable. The design offers the potential for the production of ultrahigh toroidal fields. Included are representative coil shapes and their engineering properties, a suggested structural design and an analysis of a specific case.

  2. Standard Specifications for Language Laboratory.

    ERIC Educational Resources Information Center

    North Carolina State Dept. of Administration, Raleigh.

    Specifications are presented covering the components of electronic and electro-mechanical equipment, non-electrical materials for the teacher-student positions, and other items of a miscellaneous nature to provide for a complete, workable language laboratory facility. Instructions for the use of specifications are included for the purchaser,…

  3. Response to "Transfer or Specificity?"

    ERIC Educational Resources Information Center

    Miller, Judith

    2007-01-01

    This article presents the author's response to "Transfer or Specificity?" and reports a research that supports a strong case for a fundamental motor skill as a precursor to two sport specific skills as in Gallahue and Ozmun's (2002) theoretical model of motor development. Reported changes in performance of the overarm throw are attributed to the…

  4. Technical Specifications. Revision No. 1.

    ERIC Educational Resources Information Center

    Mississippi State Dept. of Education, Jackson. Office of Educational Technology.

    The technical specifications for educational technology in the state of Mississippi which are contained in this publication represent the minimum criteria for utilization of the equipment. Information is provided for PC (personal computer) and Macintosh platforms where applicable on: workstation specifications; multimedia/teacher presentation…

  5. Hanford Site environmental management specification

    SciTech Connect

    Grygiel, M.L.

    1998-06-10

    The US Department of Energy, Richland Operations Office (RL) uses this Hanford Site Environmental Management Specification (Specification) to document top-level mission requirements and planning assumptions for the prime contractors involved in Hanford Site cleanup and infrastructure activities under the responsibility of the US Department of Energy, Office of Environmental Management. This Specification describes at a top level the activities, facilities, and infrastructure necessary to accomplish the cleanup of the Hanford Site and assigns this scope to Site contractors and their respective projects. This Specification also references the key National Environmental Policy Act of 1969 (NEPA), Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), and safety documentation necessary to accurately describe the cleanup at a summary level. The information contained in this document reflects RL`s application of values, priorities, and critical success factors expressed by those involved with and affected by the Hanford Site project. The prime contractors and their projects develop complete baselines and work plans to implement this Specification. These lower-level documents and the data that support them, together with this Specification, represent the full set of requirements applicable to the contractors and their projects. Figure 1-1 shows the relationship of this Specification to the other basic Site documents. Similarly, the documents, orders, and laws referenced in this specification represent only the most salient sources of requirements. Current and contractual reference data contain a complete set of source documents.

  6. Performance Specifications for Occupational Programs.

    ERIC Educational Resources Information Center

    Maryland State Dept. of Education, Baltimore. Div. of Career Technology and Adult Learning.

    This document lists and discusses the development of Maryland's performance specifications for occupational programs. The introduction explains the process used to develop performance standards and specifications for 10 career cluster majors that were identified by a task force of educators and employers as high-demand occupational areas in…

  7. The Development of Educational Specifications.

    ERIC Educational Resources Information Center

    North Carolina State Board of Education, Raleigh.

    This publication is intended to assist local boards of education, superintendents, and staff in the organization and development of educational specifications. It was written because most educators have little knowledge about the purpose, process, organization, or contents of the finished product (educational specifications). It provides a…

  8. PROPOSED SPECIFICATIONS FOR INERTIAL SURVEYING.

    USGS Publications Warehouse

    Chapman, William H.

    1983-01-01

    The purpose of this paper is to continue the movement toward placing inertial surveying instruments in the toolbox of the geodetic surveyor. A set of specifications is proposed for performing horizontal geodetic surveys with inertial instruments that will meet the Federal Geodetic Control Committee (FGCC) second- and third-order standards. These specifications are tentative.

  9. Standard technical specifications, Westinghouse Plants: Specifications. Volume 1, Revision 1

    SciTech Connect

    1995-04-01

    This NUREG contains the improved Standard Technical Specifications (STS) for Westinghouse plants. Revision 1 incorporates the cumulative changes to Revision 0, which was published in September 1992. The changes reflected in Revision 1 resulted from the experience gained from license amendment applications to convert to these improved STS or to adopt partial improvements to existing technical specifications. This NUREG is the result of extensive public technical meetings and discussions between the Nuclear Regulatory Commission (NRC) staff and various nuclear power plant licensees, Nuclear Steam Supply System (NSSS) Owners Groups, specifically the Westinghouse Owners Group (WOG), NSSS vendors, and the Nuclear Energy Institute (NEI). The improved STS were developed based on the criteria in the Final Commission Policy Statement on Technical Specifications Improvements for Nuclear Power Reactors, dated July 22, 1993 (58 FR 39132). Licensees are encouraged to upgrade their technical specifications consistent with those criteria and conforming, to the extent practical and consistent with the licensing basis for the facility, to Revision 1 to the improved STS. The Commission continues to place the highest priority on requests for complete conversions to the improved STS. Licensees adopting portions of the improved STS to existing technical specifications should adopt all related requirements, as applicable, to achieve a high degree of standardization and consistency.

  10. Information capacity of specific interactions.

    PubMed

    Huntley, Miriam H; Murugan, Arvind; Brenner, Michael P

    2016-05-24

    Specific interactions are a hallmark feature of self-assembly and signal-processing systems in both synthetic and biological settings. Specificity between components may arise from a wide variety of physical and chemical mechanisms in diverse contexts, from DNA hybridization to shape-sensitive depletion interactions. Despite this diversity, all systems that rely on interaction specificity operate under the constraint that increasing the number of distinct components inevitably increases off-target binding. Here we introduce "capacity," the maximal information encodable using specific interactions, to compare specificity across diverse experimental systems and to compute how specificity changes with physical parameters. Using this framework, we find that "shape" coding of interactions has higher capacity than chemical ("color") coding because the strength of off-target binding is strongly sublinear in binding-site size for shapes while being linear for colors. We also find that different specificity mechanisms, such as shape and color, can be combined in a synergistic manner, giving a capacity greater than the sum of the parts. PMID:27155013

  11. Apoptin: specific killer of tumor cells?

    PubMed

    Tavassoli, M; Guelen, L; Luxon, B A; Gäken, J

    2005-08-01

    In the early 1990s it was discovered that the VP3/Apoptin protein encoded by the Chicken Anemia virus (CAV) possesses an inherent ability to specifically kill cancer cells. Apoptin was found to be located in the cytoplasm of normal cells while in tumor cells it was localized mainly in the nucleus.(1) These differences in the localization pattern were suggested to be the main mechanism by which normal cells show resistance to Apoptin-mediated cell killing. Although the mechanism of action of Apoptin is presently unknown, it seems to function by the induction of programmed cell death (PCD) after translocation from the cytoplasm to the nucleus and arresting the cell cycle at G2/M, possibly by interfering with the cyclosome.(2) In addition, cancer specific phosphorylation of Threonine residue 108 has been suggested to be important for Apoptin's function to kill tumor cells.(3) In contrast to the large number of publications reporting that nuclear localization, induction of PCD and phosphorylation of Apoptin is restricted to cancer cells, several recent studies have shown that Apoptin has the ability to migrate to the nucleus and induce PCD in some of the normal cell lines tested. There is evidence that high protein expression levels as well as the cellular growth rate may influence Apoptin's ability to specifically kill tumor cells. Thus far both in vitro and in vivo studies indicate that Apoptin is a powerful apoptosis inducing protein with a promising prospective utility in cancer therapy. However, here we show that several recent findings contradict some of the earlier results on the tumor specificity of Apoptin, thus creating some controversy in the field. The aim of this article is to review the available data, some published and some unpublished, which either agree or contradict the reported "black and white" tumor cell specificity of Apoptin. Understanding what factors appear to influence its function should help to develop Apoptin into a potent anti

  12. Apoptin: Specific killer of tumor cells?

    PubMed Central

    Tavassoli, M.; Guelen, L.; Luxon, B. A.; Gäken, J.

    2010-01-01

    In the early 1990s it was discovered that the VP3/Apoptin protein encoded by the Chicken Anemia virus (CAV) possesses an inherent ability to specifically kill cancer cells. Apoptin was found to be located in the cytoplasm of normal cells while in tumor cells it was localized mainly in the nucleus.1 These differences in the localization pattern were suggested to be the main mechanism by which normal cells show resistance to Apoptin-mediated cell killing. Although the mechanism of action of Apoptin is presently unknown, it seems to function by the induction of programmed cell death (PCD) after translocation from the cytoplasm to the nucleus and arresting the cell cycle at g2/M, possibly by interfering with the cyclosome.2 In addition, cancer specific phosphorylation of Threonine residue 108 has been suggested to be important for Apoptin’s function to kill tumor cells.3 In contrast to the large number of publications reporting that nuclear localization, induction of PCD and phosphorylation of Apoptin is restricted to cancer cells, several recent studies have shown that Apoptin has the ability to migrate to the nucleus and induce PCD in some of the normal cell lines tested. There is evidence that high protein expression levels as well as the cellular growth rate may influence Apoptin’s ability to specifically kill tumor cells. Thus far both in vitro and in vivo studies indicate that Apoptin is a powerful apoptosis inducing protein with a promising prospective utility in cancer therapy. However, here we show that several recent findings contradict some of the earlier results on the tumor specificity of Apoptin, thus creating some controversy in the field. The aim of this article is to review the available data, some published and some unpublished, which either agree or contradict the reported “black and white” tumor cell specificity of Apoptin. Understanding what factors appear to influence its function should help to develop Apoptin into a potent anti

  13. SSL: A software specification language

    NASA Technical Reports Server (NTRS)

    Austin, S. L.; Buckles, B. P.; Ryan, J. P.

    1976-01-01

    SSL (Software Specification Language) is a new formalism for the definition of specifications for software systems. The language provides a linear format for the representation of the information normally displayed in a two-dimensional module inter-dependency diagram. In comparing SSL to FORTRAN or ALGOL, it is found to be largely complementary to the algorithmic (procedural) languages. SSL is capable of representing explicitly module interconnections and global data flow, information which is deeply imbedded in the algorithmic languages. On the other hand, SSL is not designed to depict the control flow within modules. The SSL level of software design explicitly depicts intermodule data flow as a functional specification.

  14. Field method for sulfide determination

    SciTech Connect

    Wilson, B L; Schwarser, R R; Chukwuenye, C O

    1982-01-01

    A simple and rapid method was developed for determining the total sulfide concentration in water in the field. Direct measurements were made using a silver/sulfide ion selective electrode in conjunction with a double junction reference electrode connected to an Orion Model 407A/F Specific Ion Meter. The method also made use of a sulfide anti-oxidant buffer (SAOB II) which consists of ascorbic acid, sodium hydroxide, and disodium EDTA. Preweighed sodium sulfide crystals were sealed in air tight plastic volumetric flasks which were used in standardization process in the field. Field standards were prepared by adding SAOB II to the flask containing the sulfide crystals and diluting it to the mark with deionized deaerated water. Serial dilutions of the standards were used to prepare standards of lower concentrations. Concentrations as low as 6 ppB were obtained on lake samples with a reproducibility better than +- 10%.

  15. Transverse Schwarzschild field

    SciTech Connect

    Belinfante, F.J.

    1982-06-15

    For Schwarzschild's static spherically symmetric external field, a coordinate system is determined in which the metric field is the transverse field satisfying the coordinate conditions of Arnowitt, Deser, and Misner.

  16. Electric motor model repair specifications

    SciTech Connect

    1995-08-01

    These model repair specifications list the minimum requirements for repair and overhaul of polyphase AC squireel cage induction motors. All power ranges, voltages, and speeds of squirrel cage motors are covered.

  17. Molecular Mechanisms of Synaptic Specificity

    PubMed Central

    Margeta, Milica A.; Shen, Kang

    2011-01-01

    Synapses are specialized junctions that mediate information flow between neurons and their targets. A striking feature of the nervous system is the specificity of its synaptic connections: an individual neuron will form synapses only with a small subset of available presynaptic and postsynaptic partners. Synaptic specificity has been classically thought to arise from homophilic or heterophilic interactions between adhesive molecules acting across the synaptic cleft. Over the past decade, many new mechanisms giving rise to synaptic specificity have been identified. Synapses can be specified by secreted molecules that promote or inhibit synaptogenesis, and their source can be a neighboring guidepost cell, not just presynaptic and postsynaptic neurons. Furthermore, lineage, fate, and timing of development can also play critical roles in shaping neural circuits. Future work utilizing large-scale screens will aim to elucidate the full scope of cellular mechanisms and molecular players that can give rise to synaptic specificity. PMID:19969086

  18. Grade 6 Science Curriculum Specifications.

    ERIC Educational Resources Information Center

    Alberta Dept. of Education, Edmonton. Curriculum Branch.

    This material describes curriculum specifications for grade 6 science in Alberta. Emphases recommended are: (1) process skills (50%); (2) psychomotor skills (10%); (3) attitudes (10%); and (4) subject matter (30%). Priorities within each category are identified. (YP)

  19. Specification of pyro shock tests

    NASA Technical Reports Server (NTRS)

    Trummel, M.

    1976-01-01

    Specifications of pyro shock tests are treated as the interconnection between raw measurements (or estimates) of the environment and the various test methods available. After a definition of the environment, various aspects of test method specification are discussed including one-sided pulses, test simulation parameters, and the effects of Q. Different test configurations are considered including rigid fixture tests, pseudo-real structure, and real structure.

  20. Methods for Optimizing CRISPR-Cas9 Genome Editing Specificity.

    PubMed

    Tycko, Josh; Myer, Vic E; Hsu, Patrick D

    2016-08-01

    Advances in the development of delivery, repair, and specificity strategies for the CRISPR-Cas9 genome engineering toolbox are helping researchers understand gene function with unprecedented precision and sensitivity. CRISPR-Cas9 also holds enormous therapeutic potential for the treatment of genetic disorders by directly correcting disease-causing mutations. Although the Cas9 protein has been shown to bind and cleave DNA at off-target sites, the field of Cas9 specificity is rapidly progressing, with marked improvements in guide RNA selection, protein and guide engineering, novel enzymes, and off-target detection methods. We review important challenges and breakthroughs in the field as a comprehensive practical guide to interested users of genome editing technologies, highlighting key tools and strategies for optimizing specificity. The genome editing community should now strive to standardize such methods for measuring and reporting off-target activity, while keeping in mind that the goal for specificity should be continued improvement and vigilance. PMID:27494557

  1. mREST Interface Specification

    NASA Technical Reports Server (NTRS)

    McCartney, Patrick; MacLean, John

    2012-01-01

    mREST is an implementation of the REST architecture specific to the management and sharing of data in a system of logical elements. The purpose of this document is to clearly define the mREST interface protocol. The interface protocol covers all of the interaction between mREST clients and mREST servers. System-level requirements are not specifically addressed. In an mREST system, there are typically some backend interfaces between a Logical System Element (LSE) and the associated hardware/software system. For example, a network camera LSE would have a backend interface to the camera itself. These interfaces are specific to each type of LSE and are not covered in this document. There are also frontend interfaces that may exist in certain mREST manager applications. For example, an electronic procedure execution application may have a specialized interface for configuring the procedures. This interface would be application specific and outside of this document scope. mREST is intended to be a generic protocol which can be used in a wide variety of applications. A few scenarios are discussed to provide additional clarity but, in general, application-specific implementations of mREST are not specifically addressed. In short, this document is intended to provide all of the information necessary for an application developer to create mREST interface agents. This includes both mREST clients (mREST manager applications) and mREST servers (logical system elements, or LSEs).

  2. Magnetic fields from heterotic cosmic strings

    SciTech Connect

    Gwyn, Rhiannon; Alexander, Stephon H.; Brandenberger, Robert H.; Dasgupta, Keshav

    2009-04-15

    Large-scale magnetic fields are observed today to be coherent on galactic scales. While there exists an explanation for their amplification and their specific configuration in spiral galaxies--the dynamo mechanism--a satisfying explanation for the original seed fields required is still lacking. Cosmic strings are compelling candidates because of their scaling properties, which would guarantee the coherence on cosmological scales of any resultant magnetic fields at the time of galaxy formation. We present a mechanism for the production of primordial seed magnetic fields from heterotic cosmic strings arising from M theory. More specifically, we make use of heterotic cosmic strings stemming from M5-branes wrapped around four of the compact internal dimensions. These objects are stable on cosmological time scales and carry charged zero modes. Therefore a scaling solution of such defects will generate seed magnetic fields which are coherent on galactic scales today.

  3. Electrostatic Field Invisibility Cloak.

    PubMed

    Lan, Chuwen; Yang, Yuping; Geng, Zhaoxin; Li, Bo; Zhou, Ji

    2015-01-01

    The invisibility cloak has been drawing much attention due to its new concept for manipulating many physical fields, from oscillating wave fields (electromagnetic, acoustic and elastic) to static magnetic fields, dc electric fields, and diffusive fields. Here, an electrostatic field invisibility cloak has been theoretically investigated and experimentally demonstrated to perfectly hide two dimensional objects without disturbing their external electrostatic fields. The desired cloaking effect has been achieved via both cancelling technology and transformation optics (TO). This study demonstrates a novel way for manipulating electrostatic fields, which shows promise for a wide range of potential applications. PMID:26552343

  4. Fractal vector optical fields.

    PubMed

    Pan, Yue; Gao, Xu-Zhen; Cai, Meng-Qiang; Zhang, Guan-Lin; Li, Yongnan; Tu, Chenghou; Wang, Hui-Tian

    2016-07-15

    We introduce the concept of a fractal, which provides an alternative approach for flexibly engineering the optical fields and their focal fields. We propose, design, and create a new family of optical fields-fractal vector optical fields, which build a bridge between the fractal and vector optical fields. The fractal vector optical fields have polarization states exhibiting fractal geometry, and may also involve the phase and/or amplitude simultaneously. The results reveal that the focal fields exhibit self-similarity, and the hierarchy of the fractal has the "weeding" role. The fractal can be used to engineer the focal field. PMID:27420485

  5. Electrostatic Field Invisibility Cloak

    PubMed Central

    Lan, Chuwen; Yang, Yuping; Geng, Zhaoxin; Li, Bo; Zhou, Ji

    2015-01-01

    The invisibility cloak has been drawing much attention due to its new concept for manipulating many physical fields, from oscillating wave fields (electromagnetic, acoustic and elastic) to static magnetic fields, dc electric fields, and diffusive fields. Here, an electrostatic field invisibility cloak has been theoretically investigated and experimentally demonstrated to perfectly hide two dimensional objects without disturbing their external electrostatic fields. The desired cloaking effect has been achieved via both cancelling technology and transformation optics (TO). This study demonstrates a novel way for manipulating electrostatic fields, which shows promise for a wide range of potential applications. PMID:26552343

  6. Electrostatic Field Invisibility Cloak

    NASA Astrophysics Data System (ADS)

    Lan, Chuwen; Yang, Yuping; Geng, Zhaoxin; Li, Bo; Zhou, Ji

    2015-11-01

    The invisibility cloak has been drawing much attention due to its new concept for manipulating many physical fields, from oscillating wave fields (electromagnetic, acoustic and elastic) to static magnetic fields, dc electric fields, and diffusive fields. Here, an electrostatic field invisibility cloak has been theoretically investigated and experimentally demonstrated to perfectly hide two dimensional objects without disturbing their external electrostatic fields. The desired cloaking effect has been achieved via both cancelling technology and transformation optics (TO). This study demonstrates a novel way for manipulating electrostatic fields, which shows promise for a wide range of potential applications.

  7. External split field generator

    SciTech Connect

    Thundat, Thomas George; Van Neste, Charles W.; Vass, Arpad Alexander

    2012-02-21

    A generator includes a coil disposed about a core. A first stationary magnetic field source may be disposed on a first end portion of the core and a second stationary magnetic field source may be disposed on a second end portion of core. The first and second stationary magnetic field sources apply a stationary magnetic field to the coil. An external magnetic field source may be disposed outside the coil to apply a moving magnetic field to the coil. Electrical energy is generated in response to an interaction between the coil, the moving magnetic field, and the stationary magnetic field.

  8. Quantifying group specificity of animal vocalizations without specific sender information

    NASA Astrophysics Data System (ADS)

    Vester, Heike; Hammerschmidt, Kurt; Timme, Marc; Hallerberg, Sarah

    2016-02-01

    Recordings of animal vocalization can lack information about sender and context. This is often the case in studies on marine mammals or in the increasing number of automated bioacoustics monitorings. Here, we develop a framework to estimate group specificity without specific sender information. We introduce and apply a bag-of-calls-and-coefficients approach (BOCCA) to study ensembles of cepstral coefficients calculated from vocalization signals recorded from a given animal group. Comparing distributions of such ensembles of coefficients by computing relative entropies reveals group specific differences. Applying the BOCCA to ensembles of calls recorded from group of long-finned pilot whales in northern Norway, we find that differences of vocalizations within social groups of pilot whales (Globicephala melas) are significantly lower than intergroup differences.

  9. Quantifying group specificity of animal vocalizations without specific sender information.

    PubMed

    Vester, Heike; Hammerschmidt, Kurt; Timme, Marc; Hallerberg, Sarah

    2016-02-01

    Recordings of animal vocalization can lack information about sender and context. This is often the case in studies on marine mammals or in the increasing number of automated bioacoustics monitorings. Here, we develop a framework to estimate group specificity without specific sender information. We introduce and apply a bag-of-calls-and-coefficients approach (BOCCA) to study ensembles of cepstral coefficients calculated from vocalization signals recorded from a given animal group. Comparing distributions of such ensembles of coefficients by computing relative entropies reveals group specific differences. Applying the BOCCA to ensembles of calls recorded from group of long-finned pilot whales in northern Norway, we find that differences of vocalizations within social groups of pilot whales (Globicephala melas) are significantly lower than intergroup differences. PMID:26986319

  10. Choosing an information system to meet specific needs.

    PubMed

    Burton, J A

    1983-07-01

    Because of the increasing number of information systems on the market today, the user must select the system wisely according to the vendor's ability to solve specific company needs. An organization must know its filing and retrieval requirements, its potential for growth, etc., and must then contact only those vendors that fit specific company requirements. The vendor's reputation in the field, service history, "after-sales support," and ability to supply cost analyses should all be examined. PMID:10263971

  11. The specificity triad: notions of disease and therapeutic specificity in biomedical reasoning

    PubMed Central

    2014-01-01

    Biomedicine is typically defined as the branch of medicine that is based on the principles of biology and biochemistry. A central tenet for biomedicine is the notion of disease and therapeutic specificity, i.e. the idea of tailored treatments for discrete disorders underpinned by specific pathologies. The present paper is concerned with how notions of disease and therapeutic specificity guide biomedical reasoning. To that end, the author proposes a model – the specificity triad – that draws on late philosopher and physician Ludwik Fleck’s concept of “style of thought” to offer a frame for investigating the intricate process through which links between disorders, mechanisms, and therapeutics are established by biomedicine. Next by applying the specificity triad model to scrutinize research efforts in two discrete areas of medicine—psychiatry and regenerative medicine—this paper seeks to stimulate pertinent discussions in and about biomedicine. These include discussions on the ambiguous epistemic status of psychiatry within contemporary biomedicine, as well as the relationship between developmental biology — historically relatively disjointed from biomedical enterprise — and the burgeoning field of regenerative medicine. PMID:25326797

  12. Velocity specificity, combination training and sport specific tasks.

    PubMed

    Cronin, J; McNair, P J; Marshall, R N

    2001-06-01

    Whether velocity-specific resistance training is important for improving functional sporting performance was investigated by studying the effect of isoinertial training velocity on netball chest pass throwing velocity. Twenty-one female netball players were randomly assigned to a strength-trained group (80% 1RM - average training velocity = .308 m/s), power-trained group (60% 1RM - average training velocity = .398 m/s) and a control group. Resistance training was combined with sport specific motion training for both groups over a ten-week training duration. Pre- and post-training testing revealed that the training velocity associated with the strength-trained group produced significantly greater improvement in mean volume of weight lifted (85kg) and mean power output (13.25 W) as compared to the power and control groups (P< 0.05). The strength-trained and power-trained groups significantly improved netball throw velocity by 12.4% and 8.8% respectively. There was no significant difference between the two groups. The validity of velocity-specific training and subsequent adaptations to improve functional sporting performance appears highly questionable, due to the disparity between training velocity and actual movement velocity (11.38 m x s(-1)) for a given sport specific task such as the netball throw it was proposed that the repeated intent to move an isoinertial load as rapidly as possible coupled with performance of the sport-specific movement promote efficient coordination and activation patterns. Such mechanisms might be more important determinants of sport-specific high velocity adaptation. PMID:11548916

  13. Wake fields and wake field acceleration

    SciTech Connect

    Bane, K.L.F.; Wilson, P.B.; Weiland, T.

    1984-12-01

    In this lecture we introduce the concepts of wake fields and wake potentials, examine some basic properties of these functions, show how they can be calculated, and look briefly at a few important applications. One such application is wake field acceleration. The wake field accelerator is capable of producing the high gradients required for future very high energy e/sup +/e/sup -/ linear colliders. The principles of wake field acceleration, and a brief description of experiments in progress in this area, are presented in the concluding section. 40 references, 27 figures.

  14. 1997 hybrid electric vehicle specifications

    SciTech Connect

    Sluder, S.; Larsen, R.; Duoba, M.

    1996-10-01

    The US DOE sponsors Advanced Vehicle Technology competitions to help educate the public and advance new vehicle technologies. For several years, DOE has provided financial and technical support for the American Tour de Sol. This event showcases electric and hybrid electric vehicles in a road rally across portions of the northeastern United States. The specifications contained in this technical memorandum apply to vehicles that will be entered in the 1997 American Tour de Sol. However, the specifications were prepared to be general enough for use by other teams and individuals interested in developing hybrid electric vehicles. The purpose of the specifications is to ensure that the vehicles developed do not present a safety hazard to the teams that build and drive them or to the judges, sponsors, or public who attend the competitions. The specifications are by no means the definitive sources of information on constructing hybrid electric vehicles - as electric and hybrid vehicles technologies advance, so will the standards and practices for their construction. In some cases, the new standards and practices will make portions of these specifications obsolete.

  15. Technical specification for vacuum systems

    SciTech Connect

    Khaw, J.

    1987-01-01

    The vacuum systems at the Stanford Linear Accelerator Center (SLAC) are primarily of all-metal construction and operate at pressures from 10/sup -5/ to 10/sup -11/ Torr. The primary gas loads during operation result from thermal desorption and beam-induced desorption from the vacuum chamber walls. These desorption rates can be extremely high in the case of hydrocarbons and other contaminants. These specifications place a major emphasis on eliminating contamination sources. The specifications and procedures have been written to insure the cleanliness and vacuum integrity of all SLAC vacuum systems, and to assist personnel involved with SLAC vacuum systems in choosing and designing components that are compatible with existing systems and meet the quality and reliability of SLAC vacuum standards. The specification includes requirements on design, procurement, fabrication, chemical cleaning, clean room practices, welding and brazing, helium leak testing, residual gas analyzer testing, bakeout, venting, and pumpdown. Also appended are specifications regarding acceptable vendors, isopropyl alcohol, bakeable valve cleaning procedure, mechanical engineering safety inspection, notes on synchrotron radiation, and specifications of numerous individual components. (LEW)

  16. Specificity of hammerhead ribozyme cleavage.

    PubMed Central

    Hertel, K J; Herschlag, D; Uhlenbeck, O C

    1996-01-01

    To be effective in gene inactivation, the hammerhead ribozyme must cleave a complementary RNA target without deleterious effects from cleaving non-target RNAs that contain mismatches and shorter stretches of complementarity. The specificity of hammerhead cleavage was evaluated using HH16, a well-characterized ribozyme designed to cleave a target of 17 residues. Under standard reaction conditions, HH16 is unable to discriminate between its full-length substrate and 3'-truncated substrates, even when six fewer base pairs are formed between HH16 and the substrate. This striking lack of specificity arises because all the substrates bind to the ribozyme with sufficient affinity so that cleavage occurs before their affinity differences are manifested. In contrast, HH16 does exhibit high specificity towards certain 3'-truncated versions of altered substrates that either also contain a single base mismatch or are shortened at the 5' end. In addition, the specificity of HH16 is improved in the presence of p7 nucleocapsid protein from human immunodeficiency virus (HIV)-1, which accelerates the association and dissociation of RNA helices. These results support the view that the hammerhead has an intrinsic ability to discriminate against incorrect bases, but emphasizes that the high specificity is only observed in a certain range of helix lengths. Images PMID:8670879

  17. Second Language Tests for Specific Purpose: How Specific?

    ERIC Educational Resources Information Center

    Ricciardi, Joseph S.

    1981-01-01

    This paper discusses certain problems that can arise with respect to the selection of content in the preparation of a test to measure language proficiency for some specific purpose. Forty employees in a defense plant in Montreal, Canada were interviewed in order to specify language needs, to arrive at a precise interpretation of the required…

  18. Compiler writing system detail design specification. Volume 1: Language specification

    NASA Technical Reports Server (NTRS)

    Arthur, W. J.

    1974-01-01

    Construction within the Meta language for both language and target machine specification is reported. The elements of the function language as a meaning and syntax are presented, and the structure of the target language is described which represents the target dependent object text representation of applications programs.

  19. Depth of field in modern thermal imaging

    NASA Astrophysics Data System (ADS)

    Schuster, Norbert; Franks, John

    2015-05-01

    Modern thermal imaging lenses for uncooled detectors are high aperture systems. Very often, their aperture based fnumber is faster than 1.2. The impact of this on the depth of field is dramatic, especially for narrow field lenses. The users would like to know how the image quality changes with and without refocusing for objects at different distances from the camera core. The Depth of Field approach presented here is based on the lens specific Through Focus MTF. It will be averaged for the detector area. The lens specific Through Focus MTF will be determined at the detector Nyquist frequency, which is defined by the pixel pitch. In this way, the specific lens and the specific FPA-geometry (pixel pitch, detector area) are considered. The condition, that the Through Focus MTF at full Nyquist must be higher than 0.25, defines a certain symmetrical depth of focus. This criterion provides a good discrimination for reasonable lens/detector combinations. The examples chosen reflect the actual development of uncooled camera cores. The symmetrical depth of focus is transferred to object space using paraxial relations. This defines a typical depth of field diagram containing three functions: Hyperfocal distance, nearest and furthest distance versus sharp distance (best focus). Pictures taken with an IR Camera illustrate the effect in the depth of field and its dependence on focal length. These pictures confirm the methodology. A separate problem is the acceptable drop of resolution in combination with a specific camera core and specific object scenes. We propose to evaluate the MTF-graph at half Nyquist frequency. This quantifies the resolution loss without refocus in accordance with the IR-picture degradation at the limits of the Depth of Field. The approach is applied to different commercially available lenses. Pictures illustrate the Depth of Field for different pixel pitches and pixel counts.

  20. Field Trips. Beginnings Workshop.

    ERIC Educational Resources Information Center

    Cartwright, Sally; Aronson, Susan S.; Stacey, Susan; Winbush, Olga

    2001-01-01

    Five articles highlight benefits and organization of field trips: (1) "Field Trips Promote Child Learning at Its Best"; (2) "Planning for Maximum Benefit, Minimum Risk"; (3) "Coaching Community Hosts"; (4) "The Story of a Field Trip: Trash and Its Place within Children's Learning and Community"; and (5) "Field Trip Stories and Perspectives" (from…

  1. PREPROCESSING MAGNETIC FIELDS WITH CHROMOSPHERIC LONGITUDINAL FIELDS

    SciTech Connect

    Yamamoto, Tetsuya T.; Kusano, K.

    2012-06-20

    Nonlinear force-free field (NLFFF) extrapolation is a powerful tool for the modeling of the magnetic field in the solar corona. However, since the photospheric magnetic field does not in general satisfy the force-free condition, some kind of processing is required to assimilate data into the model. In this paper, we report the results of new preprocessing for the NLFFF extrapolation. Through this preprocessing, we expect to obtain magnetic field data similar to those in the chromosphere. In our preprocessing, we add a new term concerning chromospheric longitudinal fields into the optimization function proposed by Wiegelmann et al. We perform a parameter survey of six free parameters to find minimum force- and torque-freeness with the simulated-annealing method. Analyzed data are a photospheric vector magnetogram of AR 10953 observed with the Hinode spectropolarimeter and a chromospheric longitudinal magnetogram observed with SOLIS spectropolarimeter. It is found that some preprocessed fields show the smallest force- and torque-freeness and are very similar to the chromospheric longitudinal fields. On the other hand, other preprocessed fields show noisy maps, although the force- and torque-freeness are of the same order. By analyzing preprocessed noisy maps in the wave number space, we found that small and large wave number components balance out on the force-free index. We also discuss our iteration limit of the simulated-annealing method and magnetic structure broadening in the chromosphere.

  2. Electromagnetic properties of high specific surface minerals

    NASA Astrophysics Data System (ADS)

    Klein, Katherine Anne

    Interparticle electrical forces play a dominant role in the behaviour of high specific surface minerals, such as clays. This fact encourages the use of small electromagnetic perturbations to assess the microscale properties of these materials. Thus, this research focuses on using electromagnetic waves to understand fundamental particle-particle and particle-fluid interactions, and fabric formation in high specific surface mineral-fluid mixtures (particle size <~1 μm). Topics addressed in this study include: the role of specific surface and double layer phenomena in the engineering behaviour of clay-water-electrolyte mixtures; the interplay between surface conduction, double layer polarization, and interfacial polarization; the relationship between fabric, permittivity, shear wave velocity, and engineering properties in soft slurries; and the effect of ferromagnetic impurities on electromagnetic measurements. The critical role of specific surface on the engineering properties of fine-grained soils is demonstrated through fundamental principles and empirical correlations. Afterwards, the effect of specific surface on the electromagnetic properties of particulate materials is studied using simple microscale analyses of conduction and polarization phenomena in particle-fluid mixtures, and corroborated by experimentation. These results clarify the relative importance of specific surface, water content, electrolyte type, and ionic concentration on the electrical properties of particulate materials. The sensitivity of electromagnetic parameters to particle orientation is addressed in light of the potential assessment of anisotropy in engineering properties. It is shown that effective conductivity measurements provide a robust method to determine electrical anisotropy in particle-fluid mixtures. However, real relative dielectric measurements at frequencies below 1 MHz are unreliable due to electrode effects (especially in highly conductive mixtures). The relationship

  3. High specific heat superconducting composite

    DOEpatents

    Steyert, Jr., William A.

    1979-01-01

    A composite superconductor formed from a high specific heat ceramic such as gadolinium oxide or gadolinium-aluminum oxide and a conventional metal conductor such as copper or aluminum which are insolubly mixed together to provide adiabatic stability in a superconducting mode of operation. The addition of a few percent of insoluble gadolinium-aluminum oxide powder or gadolinium oxide powder to copper, increases the measured specific heat of the composite by one to two orders of magnitude below the 5.degree. K. level while maintaining the high thermal and electrical conductivity of the conventional metal conductor.

  4. Automotive Lubricant Specification and Testing

    NASA Astrophysics Data System (ADS)

    Fox, M. F.

    This chapter concerns commercial lubricant specification and testing, drawing together the many themes of previous chapters. Military lubricant standards were a very strong initial influence during World War II and led to the separate historical development of the North American and European specification systems. The wide range of functions that a successful lubricant must satisfy is discussed, together with issues of balancing special or universal applications, single or multiple engine tests, the philosophy of accelerated testing and the question of 'who sets the standards?' The role of engine tests and testing organisations is examined.

  5. Host Specificity of Bacterial Pathogens

    PubMed Central

    Bäumler, Andreas; Fang, Ferric C.

    2013-01-01

    Most pathogens are able to infect multiple hosts but some are highly adapted to a single-host species. A detailed understanding of the basis of host specificity can provide important insights into molecular pathogenesis, the evolution of pathogenic microbes, and the potential for pathogens to cross the species barrier to infect new hosts. Comparative genomics and the development of humanized mouse models have provided important new tools with which to explore the basis of generalism and specialism. This review will examine host specificity of bacterial pathogens with a focus on generalist and specialist serovars of Salmonella enterica. PMID:24296346

  6. Undulator A characteristics and specifications

    SciTech Connect

    Lai, B.; Khounsary, A.; Savoy, R.; Moog, L.; Gluskin, E.

    1993-02-01

    The Advanced Photon Source (APS) Undulator A is a planar device optimized for the hard x-ray region. In the mature phase of operation, it satisfies the requirement of providing high brilliance x-rays continuously over the tuning range from 4.2 key to above 30 key, using the first and the third harmonic radiation from the undulator. This is achieved through the choice of the 3.3-cm long period, the hybrid undulator design, and the stringent requirements on the magnetic field quality. The undulator is 2.4 m long (including the end sections) with 72 periods. The magnetic structure consists of Nd-Fe-B magnets with vanadium permendur poles. The field errors are specified in this paper to ensure that the third harmonic radiation from the actual device will achieve at least 70% of its theoretical brilliance. The first harmonic is less sensitive to field errors and thus should attain brilliance even closer to the theoretical value. The predicted magnetic fields at various gap values based on a detail design of the magnetic structure of Undulator A are listed in this paper.

  7. Cell-Specific Promoters Enable Lipid-Based Nanoparticles to Deliver Genes to Specific Cells of the Retina In Vivo

    PubMed Central

    Wang, Yuhong; Rajala, Ammaji; Cao, Binrui; Ranjo-Bishop, Michelle; Agbaga, Martin-Paul; Mao, Chuanbin; Rajala, Raju V.S.

    2016-01-01

    Non-viral vectors, such as lipid-based nanoparticles (liposome-protamine-DNA complex [LPD]), could be used to deliver a functional gene to the retina to correct visual function and treat blindness. However, one of the limitations of LPD is the lack of cell specificity, as the retina is composed of seven types of cells. If the same gene is expressed in multiple cell types or is absent from one desired cell type, LPD-mediated gene delivery to every cell may have off-target effects. To circumvent this problem, we have tested LPD-mediated gene delivery using various generalized, modified, and retinal cell-specific promoters. We achieved retinal pigment epithelium cell specificity with vitelliform macular dystrophy (VMD2), rod cell specificity with mouse rhodopsin, cone cell specificity with red/green opsin, and ganglion cell specificity with thymocyte antigen promoters. Here we show for the first time that cell-specific promoters enable lipid-based nanoparticles to deliver genes to specific cells of the retina in vivo. This work will inspire investigators in the field of lipid nanotechnology to couple cell-specific promoters to drive expression in a cell- and tissue-specific manner. PMID:27446487

  8. Copula method for specific Burr distribution

    NASA Astrophysics Data System (ADS)

    Ismail, Nor Hidayah Binti; Khalid, Zarina Binti Mohd

    2015-02-01

    Copula method is discovered to become a useful method to joint two distributions and is known as dependence functions. It is a multivariate distribution functions whose one-dimensional margins are uniform on the interval (0, 1). The used of copula has expanded in many fields of study. Copula has many classes and families. However, in this research, copula methods which are Ali-Mikhail-Haq (AMH), Clayton and Gumbel are used on uncensored data to join specific Burr Type III and XII distributions using the theorem and algorithm of construction the copula. The result showed that AMH, Clayton and Gumbel copula fitted well with Burr distribution since the values of copula lie on the interval (0, 1).

  9. Adaptive Assessments Using Open Specifications

    ERIC Educational Resources Information Center

    Leon, Hector Barbosa; Garcia-Penalvo, Francisco J.; Rodriguez-Conde, Maria Jose; Morales, Erla M.; de Pablos, Patricia Ordonez

    2012-01-01

    Evaluation is a key element in formal education processes; it must be constructed in a way that the item questions within help students understand by adapting them to the learning style as well. The focus of the present research work specifically in the convenience to adapt an associated multimedia material in each single question besides the…

  10. Reflight certification software design specifications

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The PDSS/IMC Software Design Specification for the Payload Development Support System (PDSS)/Image Motion Compensator (IMC) is contained. The PDSS/IMC is to be used for checkout and verification of the IMC flight hardware and software by NASA/MSFC.

  11. 46 CFR Sec. 3 - Specifications.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 8 2011-10-01 2011-10-01 false Specifications. Sec. 3 Section 3 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION A-NATIONAL SHIPPING AUTHORITY PROCEDURE FOR ACCOMPLISHMENT OF VESSEL REPAIRS UNDER NATIONAL SHIPPING AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec....

  12. 46 CFR Sec. 3 - Specifications.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 8 2014-10-01 2014-10-01 false Specifications. Sec. 3 Section 3 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION A-NATIONAL SHIPPING AUTHORITY PROCEDURE FOR ACCOMPLISHMENT OF VESSEL REPAIRS UNDER NATIONAL SHIPPING AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec....

  13. 46 CFR Sec. 3 - Specifications.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Specifications. Sec. 3 Section 3 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION A-NATIONAL SHIPPING AUTHORITY PROCEDURE FOR ACCOMPLISHMENT OF VESSEL REPAIRS UNDER NATIONAL SHIPPING AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec....

  14. 46 CFR Sec. 3 - Specifications.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 8 2013-10-01 2013-10-01 false Specifications. Sec. 3 Section 3 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION A-NATIONAL SHIPPING AUTHORITY PROCEDURE FOR ACCOMPLISHMENT OF VESSEL REPAIRS UNDER NATIONAL SHIPPING AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec....

  15. 46 CFR Sec. 3 - Specifications.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 8 2012-10-01 2012-10-01 false Specifications. Sec. 3 Section 3 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION A-NATIONAL SHIPPING AUTHORITY PROCEDURE FOR ACCOMPLISHMENT OF VESSEL REPAIRS UNDER NATIONAL SHIPPING AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec....

  16. 76 FR 7482 - Operations Specifications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-10

    ... in common carriage (75 FR 25127). Specifically, the FAA proposed to clarify and standardize the rules... Printing Office's Web page at http://www.gpoaccess.gov/fr/index.html . You can also get a copy by sending a... attendants not identified by gender--140 pounds. (ii) Oil--350 pounds or the oil capacity as specified on...

  17. EDUCATIONAL SPECIFICATIONS FOR SECONDARY SCHOOLS.

    ERIC Educational Resources Information Center

    FLANIGAN, VIRGINIA; AND OTHERS

    THE REPORT CAN BE USED AS A GUIDE IN THE PREPARATION OF EDUCATIONAL SPECIFICATIONS FOR SECONDARY SCHOOLS. NEW CURRICULA, METHODS OF INSTRUCTION, AND TEACHING AIDS ADD TO THE SOPHISTICATION OF EDUCATION. PROGRAMS ENCOMPASS MANY AREAS OF EDUCATION, EACH REQUIRING PROFESSIONAL DECISIONS. THESE DECISIONS MUST BE ORGANIZED INTO WRITTEN SPECIFICATIONS…

  18. Portable File Format (PFF) specifications.

    SciTech Connect

    Dolan, Daniel H.,

    2015-02-01

    Created at Sandia National Laboratories, the Portable File Format (PFF) allows binary data transfer across computer platforms. Although this capability is supported by many other formats, PFF files are still in use at Sandia, particularly in pulsed power research. This report provides detailed PFF specifications for accessing data without relying on legacy code.

  19. Netware-Specific Network Security.

    ERIC Educational Resources Information Center

    Snyder, Robin M.

    This paper focuses on practical and cost-effective NetWare-specific approaches to information systems and computer security. A series of real world experiences is presented that illustrate fundamental information systems and security concepts. A NetWare network is a client-server network which uses a file server to share files while client…

  20. Specificity and Variability of Practice.

    ERIC Educational Resources Information Center

    Shea, Charles H.; Kohl, Robert M.

    1990-01-01

    Describes two experiments which examined how supplementing specific practice experiences with variable practice experiences influenced motor skill retention. Participants received varying trials of acquisition practice on a criterion force production task. Acquisition practice with variations of the criterion task led to better retention than…

  1. Specificity of Cardiovascular Endurance Training.

    ERIC Educational Resources Information Center

    Riley, Calberth B., Jr.; Johnson, James H.

    This study determined the specificity of cardiovascular endurance training on a bicycle ergometer. Eighteen male subjects were tested on a heart rate response test of 150 beats per minute on a bicycle ergometer at the pace of 50 revolutions per minute (rpm) and at 160 beats per minute at 60 and 80 rpm, with the resistance equal to the force of…

  2. Geoscience Field Education: A Recent Resurgence

    NASA Astrophysics Data System (ADS)

    Whitmeyer, Steven J.; Mogk, David W.

    2009-10-01

    Field education traditionally has been an integral component of undergraduate geoscience curricula. Students have learned the fundamentals of field techniques during core geology courses and have honed their field credentials during class-specific field trips, semester-long field courses, and capstone summer field camps. In many geoscience departments, field camp remains a graduation requirement, and more than 100 field camps currently are offered by U.S. universities and colleges (see http://geology.com/field-camp.shtml). During the past several decades, however, many geoscience departments have moved away from traditional geologic fieldwork and toward a broader theoretical and laboratory-intensive focus that encompasses a range of subdisciplines. Trends that have influenced these shifts include (1) the decline in the late twentieth century of the petroleum and mining industries, which have consistently championed the values of fieldwork; (2) a decrease in the number of professional jobs that incorporate field mapping; (3) a decline in the number of geoscience majors nationwide [American Geological Institute (AGI), 2009]; and (4) barriers to fieldwork, including time requirements, cost, liability, and decreasing access to field sites.

  3. Addressing the Mathematics-Specific Needs of Beginning Mathematics Teachers

    ERIC Educational Resources Information Center

    Britton, Edward

    2012-01-01

    Beginning mathematics teachers at the secondary level (middle and high school grades) have mathematics-specific needs that induction programs should address more substantially. However, a number of issues in how programs can accomplish this are more complex than often framed in discussions occurring in the induction programs and the field of…

  4. Delineating site-specific management units with proximal sensors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conventional farming uniformly manages fields with no consideration for spatial variability. This causes reduced productivity, misuse of finite resources (e.g., water and fertilizer), and detriment impacts on the environment. Site-specific management units (SSMUs) have been proposed as a means of ...

  5. English for Specific Purposes (ESP): A Holistic Review

    ERIC Educational Resources Information Center

    Rahman, Momtazur

    2015-01-01

    English for Specific Purposes, known as acronym-"ESP", has been a distinct activity in the field of English Language Teaching (ELT) since 1960s. The flowering period of ESP has been identified due to many incidents like the second world war in 1945, the rapid expansion in scientific, the growth of science and technology, the increased…

  6. The Continuing Evolution of Languages for Specific Purposes

    ERIC Educational Resources Information Center

    Grosse, Christine Uber; Voght, Geoffrey M.

    2012-01-01

    This overview to "The Modern Language Journal"'s Focus Issue on Languages for Specific Purposes (LSP) takes a fresh look at issues examined in a 1991 article by Grosse and Voght. Reflecting on change drivers and growth in LSP, the authors comment on current challenges to the field and future research needs. Their remarks are based on new insights…

  7. Multispectral Imaging Technology for Site-Specific Crop Fertilization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural fields are variable and require site-specific crop management. Nitrogen (N) is an essential nutrient required for plant growth and is a major component of the chlorophyll molecule enhancing photosynthesis. However, excessive N fertilizer leaches into groundwater and creates serious envi...

  8. Wireless Site-specific Irrigation - The Future of Intelligent Agriculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A wireless site-specific irrigation system was developed with a distributed wireless sensor network. The system allows growers to remotely access field conditions and an irrigation operation at the home or office via wireless radio communication, directing individual sprinklers on how much water to ...

  9. English for Specific Purposes: Negotiating Needs, Possibilities, and Promises

    ERIC Educational Resources Information Center

    Salas, Spencer; Mercado, Leonardo A.; Ouedraogo, Lynn Hanson; Musetti, Bernadette

    2013-01-01

    The authors espouse the need for negotiation in designing and delivering English for Specific Purposes (ESP) programs. Such negotiations take into account learners' needs as well as structural limitations of the context and candid assessment of ESP providers. The article explores lessons from the field and the importance of needs analysis.

  10. [Specific anaesthetic procedures for nasal and sinus surgery].

    PubMed

    Boisson-Bertrand, D; Jacquot, C

    2014-12-01

    In nasal and sinus surgery, the anaesthetist must share the operating field with the surgeon and take into account some patients' specific pathologies. Bleeding must be avoided by different means but the accurate gesture of the surgeon, added to the properties of the new anaesthetic drugs, may reduce the risk of this functional surgery. PMID:25458457

  11. Evaluation of potential water conservation using site-specific irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With the advent of site-specific variable-rate irrigation (VRI) systems, irrigation can be spatially managed within sub-field-sized zones. Spatial irrigation management can optimize spatial water use efficiency and may conserve water. Spatial VRI systems are currently being managed by consultants ...

  12. [MHC tetramers: tracking specific immunity].

    PubMed

    Kosor, Ela; Gagro, Alenka; Drazenović, Vladimir; Kuzman, Ilija; Jeren, Tatjana; Rakusić, Snjezana; Rabatić, Sabina; Markotić, Alemka; Gotovac, Katja; Sabioncello, Ante; Cecuk, Esma; Kerhin-Brkljacić, Vesna; Gjenero-Margan, Ira; Kaić, Bernard; Mlinarić-Galinović, Gordana; Kastelan, Andrija; Dekaris, Dragan

    2003-01-01

    In an adaptive immune response, antigen is recognized by two distinct sets of highly variable receptor molecules: (1) immunoglobulins, that serve as antigen receptors on B cells and (2) the antigen-specific receptors on T cells. T cells play important role in the control of infection and in the development of protective immunity. These cells can also mediate anti-tumor effects and, in case of autoimmune syndromes, contribute to the development and pathology of disease. The specificity of T cells is determined by T cell receptors (TCR). Understanding of the success of immune responses requires the direct measurement of antigen-specific T lymphocytes. Cell with major histocompatibility complex (MHC) class I molecules are able to present antigens to antigen-specific CD8+ cytotoxic T lymphocytes. MHC class I molecules present small peptides (epitopes) processed from intracellular antigens such as viruses and intracellular bacteria. MHC class I molecules in humans are designated as human leukocyte antigen (HLA) class I and divided into HLA-A, -B and -C. CD8+ T cells recognize MHC class I molecules and after activation produce proteins that destroy infected cells. MHC class II molecules receive their peptides mainly from extracellular and soluble antigens and present them to the CD4+ T helper cells. A recently described technique that can be used in flow cytometry enables us to quantify ex vivo antigen-specific T cells by binding of soluble tetramer MHC-peptide complexes attached to fluorochrome. Quantitative analyses of antigen-specific T cell populations provide important information on the natural course of immune responses. The interaction of T cell receptors on T lymphocytes with tetrameric MHC-peptide complexes mimics the situation on the cell surface, and allows for reliable binding. Tetramers consist of four biotinylated HLA-peptide epitope complexes bound to streptavidin conjugated with fluorescent dye. Tetramer technology has sensitivity of detection as little

  13. Observer's Interface for JWST Observation Specifications

    NASA Astrophysics Data System (ADS)

    Link, Miranda; Douglas, Robert; Moriarty, Christopher; Roman, Anthony

    2016-01-01

    In support of the launch of the James Webb Space Telescope, various teams at STScI (the Space Telescope Science Institute) have collaborated on how to re-structure the view of a an observing program within the Astronomer's Proposal Tool (APT) to accommodate for the differences between HST and JWST. For HST APT programs, the structure is visit-dominant, and there is one generic form for entering observing information that spans all instruments with their required fields and options. This can result in sometimes showing irrelevant fields to the user for a given observing goal. Also, the generation of mosaicked observations in HST requires the user to manually calculate the position of each tile within the mosaic, accounting for positional offsets and the roll of the telescope, which is a time consuming process. Now, for JWST programs in APT, the description of the observations has been segregated by instrument and mode into discrete observing templates. Each template's form allows instrument specific choices and displays of relevant information. APT will manually manage the number of visits needed to perform the observation. This is particularly useful for mosaics and dithering with JWST. For example, users will select how they would like a mosaic to be tiled at the observation level, and the visits are automatically created. In this, visits have been re-structured to be purely informational; all editing is done at the observation level. These options and concepts are illustrated to future users via the corresponding poster.

  14. Technology-Focused Early Field Experiences in Preservice Teacher Education

    ERIC Educational Resources Information Center

    Lux, Nicholas J.

    2013-01-01

    Although a broad body of research exists on field experiences in teacher education, one specific area of inquiry lacking substantial current research is that of technology-focused early field experiences, or field experiences that occur prior to student teaching and more formal clinical experiences. To address this gap, I conducted this…

  15. Particlelike distributions of the Higgs field nonminimally coupled to gravity.

    PubMed

    Füzfa, André; Rinaldi, Massimiliano; Schlögel, Sandrine

    2013-09-20

    When the Higgs field is nonminimally coupled to gravity, there exists a family of spherically symmetric particlelike solutions to the field equations. These monopoles are the only globally regular and asymptotically flat distributions with finite energy of the Higgs field around compact objects. Moreover, spontaneous scalarization is strongly amplified for specific values of their mass and compactness. PMID:24093242

  16. Comparative analysis of pulse shape discrimination methods in a 6Li loaded plastic scintillator

    NASA Astrophysics Data System (ADS)

    Balmer, Matthew J. I.; Gamage, Kelum A. A.; Taylor, Graeme C.

    2015-07-01

    Three algorithms for discriminating between fast neutrons, thermal neutrons and gamma rays in a 6Li loaded plastic scintillator have been compared. Following a literature review of existing pulse shape discrimination techniques, the performance of the charge comparison method, triangular filtering and frequency gradient analysis were investigated in this work. The scintillator was exposed to three different mixed gamma/neutron radiation fields. The figure of merit of neutron/gamma separation was investigated over a broad energy range, as well as for the neutron capture energy region. After optimisation, all three methods were found to perform similarly in terms of neutron/gamma separation.

  17. Veteran-specific suicide prevention.

    PubMed

    York, Janet A; Lamis, Dorian A; Pope, Charlene A; Egede, Leonard E

    2013-06-01

    Suicide rates have been increasing in some subgroups of Veteran populations, such as those who have experienced combat. Several initiatives are addressing this critical need and the Department of Veterans Affairs (VA) has been recognized for its leadership. This integrative review adopts the Research Impact Framework (RIM) to address suicide-specific prevention activities targeting Veterans. The RIM is a standardized approach for developing issue narratives using four broad areas: societal-related impacts, research-related impacts, policy-related impacts, and service-related impacts. The questions addressed in this review are: (1) What are the major initiatives in Veteran-specific suicide prevention in four areas of impact-society, research, policy, and services? (2) Are there gaps related in each impact area? and (3) What are the implications of this narrative for other strategies to address suicide prevention targeting Veterans? Systematic application of the RIM identifies exemplars, milestones, gaps, and health disparity issues. PMID:23011459

  18. Isotope specific arbitrary material sorter

    SciTech Connect

    Barty, Christopher P.J.

    2015-12-08

    A laser-based mono-energetic gamma-ray source is used to provide a rapid and unique, isotope specific method for sorting materials. The objects to be sorted are passed on a conveyor in front of a MEGa-ray beam which has been tuned to the nuclear resonance fluorescence transition of the desired material. As the material containing the desired isotope traverses the beam, a reduction in the transmitted MEGa-ray beam occurs. Alternately, the laser-based mono-energetic gamma-ray source is used to provide non-destructive and non-intrusive, quantitative determination of the absolute amount of a specific isotope contained within pipe as part of a moving fluid or quasi-fluid material stream.

  19. Certifying Domain-Specific Policies

    NASA Technical Reports Server (NTRS)

    Lowry, Michael; Pressburger, Thomas; Rosu, Grigore; Koga, Dennis (Technical Monitor)

    2001-01-01

    Proof-checking code for compliance to safety policies potentially enables a product-oriented approach to certain aspects of software certification. To date, previous research has focused on generic, low-level programming-language properties such as memory type safety. In this paper we consider proof-checking higher-level domain -specific properties for compliance to safety policies. The paper first describes a framework related to abstract interpretation in which compliance to a class of certification policies can be efficiently calculated Membership equational logic is shown to provide a rich logic for carrying out such calculations, including partiality, for certification. The architecture for a domain-specific certifier is described, followed by an implemented case study. The case study considers consistency of abstract variable attributes in code that performs geometric calculations in Aerospace systems.

  20. Project X functional requirements specification

    SciTech Connect

    Holmes, S.D.; Henderson, S.D.; Kephart, R.; Kerby, J.; Mishra, S.; Nagaitsev, S.; Tschirhart, R.; /Fermilab

    2011-03-01

    Project X is a multi-megawatt proton facility being developed to support intensity frontier research in elementary particle physics, with possible applications to nuclear physics and nuclear energy research, at Fermilab. A Functional Requirements Specification has been developed in order to establish performance criteria for the Project X complex in support of these multiple missions. This paper will describe the Functional Requirements for the Project X facility and the rationale for these requirements.

  1. Pattern specificity of contrast adaptation

    PubMed Central

    Anstis, Stuart

    2014-01-01

    Contrast adaptation is specific to precisely localised edges, so that adapting to a flickering photograph makes one less sensitive to that same photograph, but not to similar photographs. When two low-contrast photos, A and B, are transparently superimposed, then adapting to a flickering high-contrast B leaves no net afterimage, but it makes B disappear from the A+B picture, which now simply looks like A. PMID:25165518

  2. Magnetic fields in ring galaxies

    NASA Astrophysics Data System (ADS)

    Moss, D.; Mikhailov, E.; Silchenko, O.; Sokoloff, D.; Horellou, C.; Beck, R.

    2016-07-01

    Context. Many galaxies contain magnetic fields supported by galactic dynamo action. The investigation of these magnetic fields can be helpful for understanding galactic evolution; however, nothing definitive is known about magnetic fields in ring galaxies. Aims: Here we investigate large-scale magnetic fields in a previously unexplored context, namely ring galaxies, and concentrate our efforts on the structures that appear most promising for galactic dynamo action, i.e. outer star-forming rings in visually unbarred galaxies. Methods: We use tested methods for modelling α-Ω galactic dynamos, taking into account the available observational information concerning ionized interstellar matter in ring galaxies. Results: Our main result is that dynamo drivers in ring galaxies are strong enough to excite large-scale magnetic fields in the ring galaxies studied. The variety of dynamo driven magnetic configurations in ring galaxies obtained in our modelling is much richer than that found in classical spiral galaxies. In particular, various long-lived transients are possible. An especially interesting case is that of NGC 4513, where the ring counter-rotates with respect to the disc. Strong shear in the region between the disc and the ring is associated with unusually strong dynamo drivers in such counter-rotators. The effect of the strong drivers is found to be unexpectedly moderate. With counter-rotation in the disc, a generic model shows that a steady mixed parity magnetic configuration that is unknown for classical spiral galaxies, may be excited, although we do not specifically model NGC 4513. Conclusions: We deduce that ring galaxies constitute a morphological class of galaxies in which identification of large-scale magnetic fields from observations of polarized radio emission, as well as dynamo modelling, may be possible. Such studies have the potential to throw additional light on the physical nature of rings, their lifetimes, and evolution.

  3. Pulsed electric field increases reproduction.

    PubMed

    Panagopoulos, Dimitris J

    2016-01-01

    Purpose To study the effect of pulsed electric field - applied in corona discharge photography - on Drosophila melanogaster reproduction, possible induction of DNA fragmentation, and morphological alterations in the gonads. Materials and methods Animals were exposed to different field intensities (100, 200, 300, and 400 kV/m) during the first 2-5 days of their adult lives, and the effect on reproductive capacity was assessed. DNA fragmentation during early- and mid-oogenesis was investigated by application of the TUNEL (Terminal deoxynucleotide transferase dUTP Nick End Labeling) assay. Sections of follicles after fixation and embedding in resins were observed for possible morphological/developmental abnormalities. Results The field increased reproduction by up to 30% by increasing reproductive capacity in both sexes. The effect increased with increasing field intensities. The rate of increase diminished at the strongest intensities. Slight induction of DNA fragmentation was observed exclusively in the nurse (predominantly) and follicle cells, and exclusively at the two most sensitive developmental stages, i.e., germarium and predominantly stage 7-8. Sections of follicles from exposed females at stages of early and mid-oogennesis other than germarium and stages 7-8 did not reveal abnormalities. Conclusions (1) The specific type of electric field may represent a mild stress factor, inducing DNA fragmentation and cell death in a small percentage of gametes, triggering the reaction of the animal's reproductive system to increase the rate of gametogenesis in order to compensate the loss of a small number of gametes. (2) The nurse cells are the most sensitive from all three types of egg chamber cells. (3) The mid-oogenesis checkpoint (stage 7-8) is more sensitive to this field than the early oogenesis one (germarium) in contrast to microwave exposure. (4) Possible therapeutic applications, or applications in increasing fertility, should be investigated. PMID:26651869

  4. Combinatorial Engineering of Dextransucrase Specificity

    PubMed Central

    Irague, Romain; Tarquis, Laurence; André, Isabelle; Moulis, Claire; Morel, Sandrine; Monsan, Pierre; Potocki-Véronèse, Gabrielle; Remaud-Siméon, Magali

    2013-01-01

    We used combinatorial engineering to investigate the relationships between structure and linkage specificity of the dextransucrase DSR-S from Leuconostoc mesenteroides NRRL B-512F, and to generate variants with altered specificity. Sequence and structural analysis of glycoside-hydrolase family 70 enzymes led to eight amino acids (D306, F353, N404, W440, D460, H463, T464 and S512) being targeted, randomized by saturation mutagenesis and simultaneously recombined. Screening of two libraries totaling 3.6.104 clones allowed the isolation of a toolbox comprising 81 variants which synthesize high molecular weight α-glucans with different proportions of α(1→3) linkages ranging from 3 to 20 %. Mutant sequence analysis, biochemical characterization and molecular modelling studies revealed the previously unknown role of peptide 460DYVHT464 in DSR-S linkage specificity. This peptide sequence together with residue S512 contribute to defining +2 subsite topology, which may be critical for the enzyme regiospecificity. PMID:24204991

  5. Specific test and evaluation plan

    SciTech Connect

    Hays, W.H.

    1997-12-09

    The purpose of this Specific Test and Evaluation Plan (STEP) is to provide a detailed written plan for the systematic testing of modifications made to the 241-AN-A Valve Pit by the W-314 Project. The STEP develops the outline for test procedures that verify the system`s performance to the established Project design criteria. The STEP is a ``lower tier`` document based on the W-314 Test and Evaluation Plan (TEP) This STEP encompasses all testing activities required to demonstrate compliance to the project design criteria as it relates to the modifications of the AN-A valve pit. The Project Design Specifications (PDS) identify the specific testing activities required for the Project. Testing includes Validations and Verifications (e.g., Commercial Grade Item Dedication activities), Factory Acceptance Tests (FATs), installation tests and inspections, Construction Acceptance Tests (CATs), Acceptance Test Procedures (ATPs), Pre-Operational Test Procedures (POTPs), and Operational Test Procedures (OTPs). It should be noted that POTPs are not required for testing of the modifications to the 241-AN-A Valve Pit. The STEP will be utilized in conjunction with the TEP for verification and validation.

  6. Chromosome specific repetitive DNA sequences

    DOEpatents

    Moyzis, Robert K.; Meyne, Julianne

    1991-01-01

    A method is provided for determining specific nucleotide sequences useful in forming a probe which can identify specific chromosomes, preferably through in situ hybridization within the cell itself. In one embodiment, chromosome preferential nucleotide sequences are first determined from a library of recombinant DNA clones having families of repetitive sequences. Library clones are identified with a low homology with a sequence of repetitive DNA families to which the first clones respectively belong and variant sequences are then identified by selecting clones having a pattern of hybridization with genomic DNA dissimilar to the hybridization pattern shown by the respective families. In another embodiment, variant sequences are selected from a sequence of a known repetitive DNA family. The selected variant sequence is classified as chromosome specific, chromosome preferential, or chromosome nonspecific. Sequences which are classified as chromosome preferential are further sequenced and regions are identified having a low homology with other regions of the chromosome preferential sequence or with known sequences of other family me This invention is the result of a contract with the Department of Energy (Contract No. W-7405-ENG-36).

  7. Magnetic field influence on paramecium motility

    SciTech Connect

    Rosen, M.F.; Rosen, A.D. )

    1990-01-01

    The influence of a moderately intense static magnetic field on movement patterns of free swimming Paramecium was studied. When exposed to fields of 0.126 T, these ciliated protozoa exhibited significant reduction in velocity as well as a disorganization of movement pattern. It is suggested that these findings may be explained on the basis of alteration in function of ion specific channels within the cell membrane.

  8. Site-specific seismic hazard analyses

    NASA Astrophysics Data System (ADS)

    Montalva, Gonzalo Andres

    Current seismic hazard analyses are generally performed using probabilistic methods. When dealing with a specific site, the typical methodology involves using a ground motion prediction equation (GMPE) to estimate the rock outcrop ground motion and associated variability, then the ground motion is propagated to the ground surface by site response analysis. The site response process is inherently variable. Including this uncertainty in site response analyses without modifying the input ground motion uncertainty produces double counting of the uncertainty associated with site response. In this dissertation the total uncertainty is partitioned into its several contributing components, quantifying these components, and proposing methods to perform site-specific seismic hazard analyses without double counting uncertainties. Four random field models were developed, and an existing one was fitted to a different database. These models can be used to generate shear-wave velocity profiles for site response analyses. Two types of models are presented, using Gaussian random fields, and using Markov Chains. The first ones showed better performance, and among those a stationary Gaussian model (stationary on rho) showed the best performance, and it is the simplest among the five models. Three GMPE's were developed, one only from surface records, one from "at-depth" records, and a third one combining surface and "at-depth" records. The results show the iv same magnitude and distance scaling for the three equations. For stations that recorded a large number of records, total uncertainty was measured by the standard deviation of the observed minus predicted, and similarly for intra-event residuals. These statistics serve as lower bounds for site-specific seismic hazard analyses, note that these standard deviations are non-ergodic. The use of a GMPE capable of predicting bedrock and surface median ground motions, allows the partition of the components of the total uncertainty at the

  9. What Are Electromagnetic Fields?

    MedlinePlus

    ... with distance from it. Conductors such as metal shield them very effectively. Other materials, such as building ... with distance from the source. Most building materials shield electric fields to some extent. Magnetic fields arise ...

  10. Dissipative Field Theory

    SciTech Connect

    Kheirandish, F.; Amooshahi, M.

    2008-11-18

    Quantum field theory of a damped vibrating string as the simplest dissipative scalar field theory is investigated by introducing a minimal coupling method. The rate of energy flowing between the system and its environment is obtained.

  11. Understanding Vector Fields.

    ERIC Educational Resources Information Center

    Curjel, C. R.

    1990-01-01

    Presented are activities that help students understand the idea of a vector field. Included are definitions, flow lines, tangential and normal components along curves, flux and work, field conservation, and differential equations. (KR)

  12. Solar Wind Magnetic Fields

    NASA Technical Reports Server (NTRS)

    Smith, E. J.

    1995-01-01

    The magnetic fields originate as coronal fields that are converted into space by the supersonic, infinitely conducting, solar wind. On average, the sun's rotation causes the field to wind up and form an Archimedes Spiral. However, the field direction changes almost continuously on a variety of scales and the irregular nature of these changes is often interpreted as evidence that the solar wind flow is turbulent.

  13. Nonperturbative Quantum Field Evolution

    NASA Astrophysics Data System (ADS)

    Zhao, Xingbo; Ilderton, Anton; Maris, Pieter; Vary, James P.

    2014-06-01

    We introduce a nonperturbative, first-principles approach to time-dependent problems in quantum field theory. In this approach, the time-evolution of quantum field configurations is calculated in real time and at the amplitude level. This method is particularly suitable for treating systems interacting with a time-dependent background field. As a test problem, we apply this approach to QED and study electron acceleration and the associated photon emission in a time- and space-dependent electromagnetic background field.

  14. Far field acceleration

    SciTech Connect

    Fernow, R.C.

    1995-07-01

    Far fields are propagating electromagnetic waves far from their source, boundary surfaces, and free charges. The general principles governing the acceleration of charged particles by far fields are reviewed. A survey of proposed field configurations is given. The two most important schemes, Inverse Cerenkov acceleration and Inverse free electron laser acceleration, are discussed in detail.

  15. Introducing Electromagnetic Field Momentum

    ERIC Educational Resources Information Center

    Hu, Ben Yu-Kuang

    2012-01-01

    I describe an elementary way of introducing electromagnetic field momentum. By considering a system of a long solenoid and line charge, the dependence of the field momentum on the electric and magnetic fields can be deduced. I obtain the electromagnetic angular momentum for a point charge and magnetic monopole pair partially through dimensional…

  16. Magnetic field sensor

    NASA Astrophysics Data System (ADS)

    Silva, Nicolas

    2012-09-01

    Earlier papers1-3 in this journal have described experiments on measuring the magnetic fields of current-carrying wires and permanent magnets using magnetic field probes of various kinds. This paper explains how to use an iPad and the free app MagnetMeter-3D Vector Magnetometer and Accelerometer4 (compass HD) to measure the magnetic fields.

  17. Politics of aviation fields

    NASA Technical Reports Server (NTRS)

    Vivent, Jacques

    1922-01-01

    In short, the "politics of aviation" lies in a few propositions: the need of having as large a number of fields as possible and of sufficient area; the utilization of the larger part of the existing military fields; the selection of uncultivated or unproductive fields, whenever technical conditions permit; ability to disregard (save in exceptional cases) objections of an agricultural nature.

  18. Chemosensory receptor specificity and regulation.

    PubMed

    Dalton, Ryan P; Lomvardas, Stavros

    2015-07-01

    The senses provide a means by which data on the physical and chemical properties of the environment may be collected and meaningfully interpreted. Sensation begins at the periphery, where a multitude of different sensory cell types are activated by environmental stimuli as different as photons and odorant molecules. Stimulus sensitivity is due to expression of different cell surface sensory receptors, and therefore the receptive field of each sense is defined by the aggregate of expressed receptors in each sensory tissue. Here, we review current understanding on patterns of expression and modes of regulation of sensory receptors. PMID:25938729

  19. String field theory and tachyon field

    NASA Astrophysics Data System (ADS)

    Yang, Yi

    In this thesis, we study Sen's conjecture on tachyon condensation by using string field theories, i.e. boundary string field theory (BSFT) and cubic string field theory (CSFT). In the BSFT side, the first explicit calculation of effective tachyon action for the bosonic string was given by Witten ten years ago and by many other authors in the last two years. It was extended to the superstring case shortly after. In our work, we give an explicit calculation of Green functions for the fermionic fields and compute the effective tachyon action for the superstring. The results we obtain agree with earlier results. We then generalize the BSFT method to one loop level. The tachyon condensation at one loop level is systematically studied, and many interesting results are obtained which verify Sen's conjecture. We also apply this method to the non-orientable theory at one loop level, where the expected divergence cancellation is reproduced and the similar effective tachyon action is obtained. By using the boundary state formalism, we verify the duality between open and closed strings. In the CSFT side, since there is no known solution to this theory, tachyon condensation can only be studied by numerical methods, i.e. level truncation. However, at the tachyon vacuum, CSFT is simplified to vacuum string field theory (VSFT) which has a solution - sliver state. By adding a tachyon vertex to the boundary of the sliver state, we have calculated the effective action.

  20. HOW IMMUNE PEPTIDASES CHANGE SPECIFICITY

    PubMed Central

    Raymond, Wilfred W.; Trivedi, Neil N.; Makarova, Anastasia; Ray, Manisha; Craik, Charles S.; Caughey, George H.

    2014-01-01

    Cathepsin G is a major secreted serine peptidase of neutrophils and mast cells. Studies in Ctsg-null mice suggest that cathepsin G supports antimicrobial defenses but can injure host tissues. The human enzyme has unusual “Janus-faced” ability to cleave peptides at basic (tryptic) as well as aromatic (chymotryptic) sites. Tryptic activity has been attributed to acidic Glu226 in the primary specificity pocket and underlies proposed important functions such as activation of pro-urokinase. However, most mammals, including mice, substitute Ala for Glu226, suggesting that human tryptic activity may be anomalous. To test this hypothesis, human cathepsin G was compared with mouse wild type and humanized active site mutants, revealing that mouse primary specificity is markedly narrower than that of human cathepsin G, with much greater Tyr activity and selectivity and near absence of tryptic activity. It also differs from human in resisting tryptic peptidase inhibitors (e.g., aprotinin), while favoring angiotensin destruction at Tyr4 over activation at Phe8. Ala226Glu mutants of mouse cathepsin G acquire tryptic activity and human ability to activate pro-urokinase. Phylogenetic analysis reveals that the Ala226Glu missense mutation appearing in primates 31–43 million years ago represented an apparently unprecedented way to create tryptic activity in a serine peptidase. We propose that tryptic activity is not an attribute of ancestral mammalian cathepsin G, which was primarily chymotryptic, and that primate-selective broadening of specificity opposed the general trend of increased specialization by immune peptidases and allowed acquisition of new functions. PMID:20889553

  1. Project X functional requirements specification

    SciTech Connect

    Holmes, S.D.; Henderson, S.D.; Kephart, R.; Kerby, J.; Kourbanis, I.; Lebedev, V.; Mishra, S.; Nagaitsev, S.; Solyak, N.; Tschirhart, R.; /Fermilab

    2012-05-01

    Project X is a multi-megawatt proton facility being developed to support a world-leading program in Intensity Frontier physics at Fermilab. The facility is designed to support programs in elementary particle and nuclear physics, with possible applications to nuclear energy research. A Functional Requirements Specification has been developed in order to establish performance criteria for the Project X complex in support of these multiple missions, and to assure that the facility is designed with sufficient upgrade capability to provide U.S. leadership for many decades to come. This paper will briefly review the previously described Functional Requirements, and then discuss their recent evolution.

  2. [Genotypic specificity of schizophrenic psychoses].

    PubMed

    Shakhmatova-Pavlova, I V; Gindilis, V M; Rokhlina, M L; Kozlova, I A

    1980-01-01

    A total of 610 probands with a disease manifestation in childhood, middle and old age and their families were examined by the clinico-genealogical method. The results allowed conclusions that (1) there is an undoubted genetic relationship between schizophrenia of childhood, middle and old age; and that (2) among the closest relatives in families of the probands there is no significant (in comparison to the general population) accumulation of non-schizophrenic pathology. The latter indicates a high genotypic specificity of schizophrenia. PMID:7415694

  3. Logic programming and metadata specifications

    NASA Technical Reports Server (NTRS)

    Lopez, Antonio M., Jr.; Saacks, Marguerite E.

    1992-01-01

    Artificial intelligence (AI) ideas and techniques are critical to the development of intelligent information systems that will be used to collect, manipulate, and retrieve the vast amounts of space data produced by 'Missions to Planet Earth.' Natural language processing, inference, and expert systems are at the core of this space application of AI. This paper presents logic programming as an AI tool that can support inference (the ability to draw conclusions from a set of complicated and interrelated facts). It reports on the use of logic programming in the study of metadata specifications for a small problem domain of airborne sensors, and the dataset characteristics and pointers that are needed for data access.

  4. Central Solenoid Insert Technical Specification

    SciTech Connect

    Martovetsky, Nicolai N; Smirnov, Alexandre

    2011-09-01

    The US ITER Project Office (USIPO) is responsible for the ITER central solenoid (CS) contribution to the ITER project. The Central Solenoid Insert (CSI) project will allow ITER validation the appropriate lengths of the conductors to be used in the full-scale CS coils under relevant conditions. The ITER Program plans to build and test a CSI to verify the performance of the CS conductor. The CSI is a one-layer solenoid with an inner diameter of 1.48 m and a height of 4.45 m between electric terminal ends. The coil weight with the terminals is approximately 820 kg without insulation. The major goal of the CSI is to measure the temperature margin of the CS under the ITER direct current (DC) operating conditions, including determining sensitivity to load cycles. Performance of the joints, ramp rate sensitivity, and stability against thermal or electromagnetic disturbances, electrical insulation, losses, and instrumentation are addressed separately and therefore are not major goals in this project. However, losses and joint performance will be tested during the CSI testing campaign. The USIPO will build the CSI that will be tested at the Central Solenoid Model Coil (CSMC) Test Facility at the Japan Atomic Energy Agency (JAEA), Naka, Japan. The industrial vendors (the Suppliers) will report to the USIPO (the Company). All approvals to proceed will be issued by the Company, which in some cases, as specified in this document, will also require the approval of the ITER Organization. Responsibilities and obligations will be covered by respective contracts between the USIPO, called Company interchangeably, and the industrial Prime Contractors, called Suppliers. Different stages of work may be performed by more than one Prime Contractor, as described in this specification. Technical requirements of the contract between the Company and the Prime Contractor will be covered by the Fabrication Specifications developed by the Prime Contractor based on this document and approved by

  5. Artificial gravity field

    NASA Astrophysics Data System (ADS)

    Markley, Larry C.; Lindner, John F.

    Using computer algebra to run Einstein's equations "backward", from field to source rather than from source to field, we design an artificial gravity field for a space station or spaceship. Everywhere inside astronauts experience normal Earth gravity, while outside they float freely. The stress-energy that generates the field contains exotic matter of negative energy density but also relies importantly on pressures and shears, which we describe. The same techniques can be readily used to design other interesting spacetimes and thereby elucidate the connection between the source and field in general relativity.

  6. Equilateral non-Gaussianity from heavy fields

    SciTech Connect

    Gong, Jinn-Ouk; Pi, Shi; Sasaki, Misao E-mail: spi@apctp.org

    2013-11-01

    The effect of self-interactions of heavy scalar fields during inflation on the primordial non-Gaussianity is studied. We take a specific constant-turn quasi-single field inflation as an example. We derive an effective theory with emphasis on non-linear self-interactions of heavy fields and calculate the corresponding non-Gaussianity, which is of equilateral type and can be as relevant as those computed previously in the literature. We also derive the non-Gaussianity by directly using the in-in formalism, and verify the equivalence of these two approaches.

  7. Oil and gas field code master list 1997

    SciTech Connect

    1998-02-01

    The Oil and Gas Field Code Master List 1997 is the sixteenth annual listing of all identified oil and gas fields in the US. It is updated with field information collected through October 1997. The purpose of this publication is to provide unique, standardized codes for identification of domestic fields. Use of these field codes fosters consistency of field identification by government and industry. As a result of their widespread adoption they have in effect become a national standard. The use of field names and codes listed in this publication is required on survey forms and other reports regarding field-specific data collected by EIA. There are 58,366 field records in this year`s FCML, 437 more than last year. The FCML includes: field records for each State and county in which a field resides; field records for each offshore area block in the Gulf of Mexico in which a field resides; field records for each alias field name (definition of alias is listed); fields crossing State boundaries that may be assigned different names by the respective State naming authorities. This report also contains an Invalid Field Record List of 4 records that have been removed from the FCML since last year`s report. These records were found to be either technically incorrect or to represent field names which were never recognized by State naming authorities.

  8. Specific bovine brucellosis diagnosis based on in vitro antigen-specific gamma interferon production.

    PubMed Central

    Weynants, V; Godfroid, J; Limbourg, B; Saegerman, C; Letesson, J J

    1995-01-01

    In order to improve the specificity of the diagnosis of bovine brucellosis, we developed a test which can be regarded as an in vitro correlate of the delayed-type hypersensitivity test (DTH). A mixture of cytoplasmic proteins from Brucella melitensis B115 was used as a specific antigenic stimulus in bovine whole blood culture. Supernatants harvested at 18 to 24 h after the in vitro antigenic stimulus were assayed for their gamma interferon (IFN-gamma) content by using a commercial sandwich enzyme-linked immunosorbent assay kit. The IFN-gamma assay was evaluated with 10 heifers during the course (80 days) of an experimental infection and with 14 cows from an ongoing brucellosis outbreak. All of these animals were slaughtered, and pertinent organs were subjected to classical bacteriological analyses. In addition, we analyzed 23 field cases in which false-positive serological reactions occurred. The IFN-gamma results were compared with those of the standard DTH and a battery of serological assays, and they were correlated with bacteriological data. Both for the experimental infection and for the field brucellosis outbreak, the IFN-gamma assay detected infection in more animals than any combination of the serological tests, and it detected infection earlier than these tests. Finally, none of the samples from cows showing false-positive serological reactions was classified as positive by the IFN-gamma assay, attesting to its specificity and to its usefulness in interpreting ambiguous serological results. A rapid and convenient alternative to the DTH, the IFN-gamma assay appears to be an ideal method that is complementary to the serological diagnosis protocols. PMID:7751381

  9. Configuration and specifications of an Unmanned Aerial Vehicle (UAV) for early site specific weed management.

    PubMed

    Torres-Sánchez, Jorge; López-Granados, Francisca; De Castro, Ana Isabel; Peña-Barragán, José Manuel

    2013-01-01

    A new aerial platform has risen recently for image acquisition, the Unmanned Aerial Vehicle (UAV). This article describes the technical specifications and configuration of a UAV used to capture remote images for early season site- specific weed management (ESSWM). Image spatial and spectral properties required for weed seedling discrimination were also evaluated. Two different sensors, a still visible camera and a six-band multispectral camera, and three flight altitudes (30, 60 and 100 m) were tested over a naturally infested sunflower field. The main phases of the UAV workflow were the following: 1) mission planning, 2) UAV flight and image acquisition, and 3) image pre-processing. Three different aspects were needed to plan the route: flight area, camera specifications and UAV tasks. The pre-processing phase included the correct alignment of the six bands of the multispectral imagery and the orthorectification and mosaicking of the individual images captured in each flight. The image pixel size, area covered by each image and flight timing were very sensitive to flight altitude. At a lower altitude, the UAV captured images of finer spatial resolution, although the number of images needed to cover the whole field may be a limiting factor due to the energy required for a greater flight length and computational requirements for the further mosaicking process. Spectral differences between weeds, crop and bare soil were significant in the vegetation indices studied (Excess Green Index, Normalised Green-Red Difference Index and Normalised Difference Vegetation Index), mainly at a 30 m altitude. However, greater spectral separability was obtained between vegetation and bare soil with the index NDVI. These results suggest that an agreement among spectral and spatial resolutions is needed to optimise the flight mission according to every agronomical objective as affected by the size of the smaller object to be discriminated (weed plants or weed patches). PMID:23483997

  10. Configuration and Specifications of an Unmanned Aerial Vehicle (UAV) for Early Site Specific Weed Management

    PubMed Central

    Torres-Sánchez, Jorge; López-Granados, Francisca; De Castro, Ana Isabel; Peña-Barragán, José Manuel

    2013-01-01

    A new aerial platform has risen recently for image acquisition, the Unmanned Aerial Vehicle (UAV). This article describes the technical specifications and configuration of a UAV used to capture remote images for early season site- specific weed management (ESSWM). Image spatial and spectral properties required for weed seedling discrimination were also evaluated. Two different sensors, a still visible camera and a six-band multispectral camera, and three flight altitudes (30, 60 and 100 m) were tested over a naturally infested sunflower field. The main phases of the UAV workflow were the following: 1) mission planning, 2) UAV flight and image acquisition, and 3) image pre-processing. Three different aspects were needed to plan the route: flight area, camera specifications and UAV tasks. The pre-processing phase included the correct alignment of the six bands of the multispectral imagery and the orthorectification and mosaicking of the individual images captured in each flight. The image pixel size, area covered by each image and flight timing were very sensitive to flight altitude. At a lower altitude, the UAV captured images of finer spatial resolution, although the number of images needed to cover the whole field may be a limiting factor due to the energy required for a greater flight length and computational requirements for the further mosaicking process. Spectral differences between weeds, crop and bare soil were significant in the vegetation indices studied (Excess Green Index, Normalised Green-Red Difference Index and Normalised Difference Vegetation Index), mainly at a 30 m altitude. However, greater spectral separability was obtained between vegetation and bare soil with the index NDVI. These results suggest that an agreement among spectral and spatial resolutions is needed to optimise the flight mission according to every agronomical objective as affected by the size of the smaller object to be discriminated (weed plants or weed patches). PMID:23483997

  11. Hanford Site Environmental Management Specification

    SciTech Connect

    DAILY, J.L.

    2001-05-25

    The US Department of Energy, Richland Operations Office (RL) has established a document hierarchy as part of its integrated management system. The Strategic Plan defines the vision, values, missions, strategic goals, high-level outcomes, and the basic strategies in achieving those outcomes. As shown in Figure 1-1, the Site Specification derives requirements from the Strategic Plan and documents the top-level mission technical requirements for the work involved in the RL Hanford Site cleanup and infrastructure activities under the responsibility of the U.S. Department of Energy, Office of Environmental Management (EM). It also provides the basis for all contract technical requirements. Since this is limited to the EM work, neither the Fast Flux Test Facility (FFTF) nor the Pacific Northwest National Laboratory (PNNL) non-EM science activities are included. Figure 1-1 also shows the relationship between this Site Specification and the other Site management and planning documents. Similarly, the documents, orders, and laws referenced in this document represent only the most salient sources of requirements. Current and contractual reference data contain a complete set of source documents.

  12. Collective specification of cellular development.

    PubMed

    Sachs, Tsvi

    2003-09-01

    Studies of chimeras and in vivo development demonstrate that cell lineages are often quite variable, apparently in response to chance perturbations. This points to an apparent contradiction: although individual cells are the units of genetic information and differentiation, not all cellular events need be precise for the development of functional organisms. The social organization of ants can serve as a metaphor that helps understand the mechanisms that underlie such development. Ants suggest that continued cellular interactions and environmental conditions could specify the proportion and general location of specialized units. Leaf venation is used as a concrete example of this general principle. A signal produced continuously by all cells specifies a requirement for vein differentiation. The cells that respond by differentiation then transport the signal away from the leaf; this removal acting as a feedback indicating that the requirement is being met. Because transport increases during vein differentiation, early initiation occurs in excess and vein 'competition' for the signal assures an acceptable outcome. Such specification would be robust since it does not depend on events in any single cell, and chance events, rather than being corrected or reversed, may be built upon in reaching an expected, collective phenotype. The absence of detailed information preceding development distinguishes this hypothesis from the common alternatives of a program or blueprint. Collective specification would have important implications for developmental plasticity and evolution. PMID:12938179

  13. Flight Guidance System Requirements Specification

    NASA Technical Reports Server (NTRS)

    Miller, Steven P.; Tribble, Alan C.; Carlson, Timothy M.; Danielson, Eric J.

    2003-01-01

    This report describes a requirements specification written in the RSML-e language for the mode logic of a Flight Guidance System of a typical regional jet aircraft. This model was created as one of the first steps in a five-year project sponsored by the NASA Langley Research Center, Rockwell Collins Inc., and the Critical Systems Research Group of the University of Minnesota to develop new methods and tools to improve the safety of avionics designs. This model will be used to demonstrate the application of a variety of methods and techniques, including safety analysis of system and subsystem requirements, verification of key properties using theorem provers and model checkers, identification of potential sources mode confusion in system designs, partitioning of applications based on the criticality of system hazards, and autogeneration of avionics quality code. While this model is representative of the mode logic of a typical regional jet aircraft, it does not describe an actual or planned product. Several aspects of a full Flight Guidance System, such as recovery from failed sensors, have been omitted, and no claims are made regarding the accuracy or completeness of this specification.

  14. Arithmetic Memory Is Modality Specific

    PubMed Central

    Myers, Timothy; Szücs, Dénes

    2015-01-01

    In regards to numerical cognition and working memory, it is an open question as to whether numbers are stored into and retrieved from a central abstract representation or from separate notation-specific representations. This study seeks to help answer this by utilizing the numeral modality effect (NME) in three experiments to explore how numbers are processed by the human brain. The participants were presented with numbers (1–9) as either Arabic digits or written number words (Arabic digits and dot matrices in Experiment 2) at the first (S1) and second (S2) stimuli. The participant’s task was to add the first two stimuli together and verify whether the answer (S3), presented simultaneously with S2, was correct. We hypothesized that if reaction time (RT) at S2/S3 depends on the modality of S1 then numbers are retrieved from modality specific memory stores. Indeed, RT depended on the modality of S1 whenever S2 was an Arabic digit which argues against the concept of numbers being stored and retrieved from a central, abstract representation. PMID:26716692

  15. Specification for soil multisensor and soil sampling cone penetrometer probes

    SciTech Connect

    Iwatate, D.F.

    1998-02-12

    Specification requirements for engineering, fabrication, and performance of cone penetrometer (CP) soil multisensor and sampling probes (CP-probes). Required to support contract procurement for services. The specification provides a documented technical basis of quality assurance that is required to use the probes in an operating Hanford tank farm. The documentation cited in this specification will be referenced as part of a readiness review and engineering task plan for a planned FY-1998 in-tank-farm CP-probe fielding task (demonstration). The probes discussed in this specification support the Hanford Tanks Initiative AX-104 Tank Plume Characterization Sub-task. The probes will be used to interrogate soils and vadose zone surrounding tank AX-104.

  16. Specification for soil multisensor and soil sampling cone penetrometer probes

    SciTech Connect

    Iwatate, D.F.

    1997-05-02

    Specification requirements for engineering, fabrication, and performance of cone penetrometer (CP) soil multisensor and sampling probes (CP-probes) which are required to support contract procurement for services are presented. The specification provides a documented technical basis of quality assurance that is required to use the probes in an operating Hanford tank farm. The documentation cited in this specification will be incorporated into an operational fielding plan that will address all activities associated with the use of the CP-probes. The probes discussed in this specification support the Hanford Tanks Initiative AX-104 Tank Plume Characterization Sub-task. The probes will be used to interrogate soils and vadose zone surrounding tank AX-104.

  17. CMB non-gaussianity from vector fields

    SciTech Connect

    Peloso, Marco

    2014-01-01

    The Planck satellite has recently measured the CMB temperature anisotropies with unprecedented accuracy, and it has provided strong bounds on primordial non-gaussianity. Such bounds constrain models of inflation, and mechanisms that produce the primordial perturbations. We discuss the non-gaussian signatures from the interactions of the inflation φ with spin-1 fields. We study the two different cases in which the inflaton is (i) a pseudo-scalar field with a (φ)/(fa) F·F interaction with a vector field, and (ii) a scalar field with a f (φ)F² interaction. In the first case we obtain the strong limit f{sub a} ≥ 10¹⁶GeV on the decay constant. In the second case, specific choices of the function f (φ) can lead to a non-gaussianity with a characteristic shape not encountered in standard models of scalar field inflation, and which has also been constrained by Planck.

  18. [The transition of deep brain stimulation from disease specific to symptom specific indications].

    PubMed

    Okun, Michael S

    2012-01-01

    The success of chronic deep brain stimulation (DBS) and electrical neuro-network modulation (ENM) to address neurological and neuropsychiatric disorders has led the Food and Drug Administration (FDA), and also other worldwide regulatory agencies to grant approval for the use of DBS in specific disorders. In the United States, DBS is FDA approved for the treatment of advanced Parkinson's disease (PD), essential tremor (ET), obsessive compulsive disorder (OCD), and for dystonia. OCD and dystonia have been approved under a mechanism referred to as a humanitarian device exemption (HDE). However, as the field of DBS and ENM evolve there has been a shift in practice patterns from targeting diseases to targeting specific and disabling symptoms. This shift has been driving interdisciplinary DBS boards to collect, and to address symptom profiles in all potential DBS candidates. Based on a specific symptom profile, a strategic and personalized medicine approach can be undertaken. The personalized approach will take into consideration the brain target, a unilateral versus a bilateral procedure, and the potential for use of more than one DBS lead per brain hemisphere. Additionally, a personalized approach to DBS will also facilitate improved pre-operative medication adjustments, as well as optimal post-operative medication, behavioral, and device management. PMID:23196455

  19. Sound Fields in Complex Listening Environments

    PubMed Central

    2011-01-01

    The conditions of sound fields used in research, especially testing and fitting of hearing aids, are usually simplified or reduced to fundamental physical fields, such as the free or the diffuse sound field. The concepts of such ideal conditions are easily introduced in theoretical and experimental investigations and in models for directional microphones, for example. When it comes to real-world application of hearing aids, however, the field conditions are more complex with regard to specific stationary and transient properties in room transfer functions and the corresponding impulse responses and binaural parameters. Sound fields can be categorized in outdoor rural and urban and indoor environments. Furthermore, sound fields in closed spaces of various sizes and shapes and in situations of transport in vehicles, trains, and aircrafts are compared with regard to the binaural signals. In laboratory tests, sources of uncertainties are individual differences in binaural cues and too less controlled sound field conditions. Furthermore, laboratory sound fields do not cover the variety of complex sound environments. Spatial audio formats such as higher-order ambisonics are candidates for sound field references not only in room acoustics and audio engineering but also in audiology. PMID:21676999

  20. On the helicity of open magnetic fields

    SciTech Connect

    Prior, C.; Yeates, A. R.

    2014-06-01

    We reconsider the topological interpretation of magnetic helicity for magnetic fields in open domains, and relate this to the relative helicity. Specifically, our domains stretch between two parallel planes, and each of these ends may be magnetically open. It is demonstrated that, while the magnetic helicity is gauge-dependent, its value in any gauge may be physically interpreted as the average winding number among all pairs of field lines with respect to some orthonormal frame field. In fact, the choice of gauge is equivalent to the choice of reference field in the relative helicity, meaning that the magnetic helicity is no less physically meaningful. We prove that a particular gauge always measures the winding with respect to a fixed frame, and propose that this is normally the best choice. For periodic fields, this choice is equivalent to measuring relative helicity with respect to a potential reference field. However, for aperiodic fields, we show that the potential field can be twisted. We prove by construction that there always exists a possible untwisted reference field.

  1. Sound fields in complex listening environments.

    PubMed

    Vorländer, Michael

    2011-09-01

    The conditions of sound fields used in research, especially testing and fitting of hearing aids, are usually simplified or reduced to fundamental physical fields, such as the free or the diffuse sound field. The concepts of such ideal conditions are easily introduced in theoretical and experimental investigations and in models for directional microphones, for example. When it comes to real-world application of hearing aids, however, the field conditions are more complex with regard to specific stationary and transient properties in room transfer functions and the corresponding impulse responses and binaural parameters. Sound fields can be categorized in outdoor rural and urban and indoor environments. Furthermore, sound fields in closed spaces of various sizes and shapes and in situations of transport in vehicles, trains, and aircrafts are compared with regard to the binaural signals. In laboratory tests, sources of uncertainties are individual differences in binaural cues and too less controlled sound field conditions. Furthermore, laboratory sound fields do not cover the variety of complex sound environments. Spatial audio formats such as higher-order ambisonics are candidates for sound field references not only in room acoustics and audio engineering but also in audiology. PMID:21676999

  2. Wiggler A characteristics and specifications

    SciTech Connect

    Lai, B.; Khounsary, A.; Gluskin, E.

    1993-02-01

    The Advanced Photon Source (APS) Wiggler A is a 2.4-m long device with an 8.5-cm period. It satisfies the requirement of achieving a peak field of 1.0 Tesla in the initial phase of operation. This will result in a critical energy of E[sub c]=32.6 key, and the device will provide radiation in a regime harder than that from the APS bending magnet. With B[sub peak]=1.0 T and [lambda][sub u]=8.5 cm, the deflection parameter K is about 7.9. This puts the device well in the wiggler regime because the first harmonic radiation from such a device wig be at 0.17 keV, far below the critical energy. The fan of radiation from a wiggler is about 2K/[lambda]1.16 mrad in the horizontal direction, and on the order of 1/[lambda]0.073 mrad in the vertical direction. As such, a K of 7.9 represents a good balance between providing a continuous and smooth spectrum without overly spreading the radiation fan in the horizontal direction. As for the source size, the excursion of the positron beam caused by the wiggler field is given by +(K/[lambda])([lambda][sub u]/2[pi]) = [plus minus]7.8 [mu]m, which is negligible compared to the positron beam size in the horizontal direction. Thus, the positron beam completely defines the source size for Wiggler A. Wiggler A has the additional capability of varying the magnetic gap. This gives considerable flexibility to the users in changing its critical energy to lower values. For operation at large gap values, the device can also provide undulator radiation below 4 keV from the first harmonic.

  3. Wiggler A characteristics and specifications

    SciTech Connect

    Lai, B.; Khounsary, A.; Gluskin, E.

    1993-02-01

    The Advanced Photon Source (APS) Wiggler A is a 2.4-m long device with an 8.5-cm period. It satisfies the requirement of achieving a peak field of 1.0 Tesla in the initial phase of operation. This will result in a critical energy of E{sub c}=32.6 key, and the device will provide radiation in a regime harder than that from the APS bending magnet. With B{sub peak}=1.0 T and {lambda}{sub u}=8.5 cm, the deflection parameter K is about 7.9. This puts the device well in the wiggler regime because the first harmonic radiation from such a device wig be at 0.17 keV, far below the critical energy. The fan of radiation from a wiggler is about 2K/{lambda}1.16 mrad in the horizontal direction, and on the order of 1/{lambda}0.073 mrad in the vertical direction. As such, a K of 7.9 represents a good balance between providing a continuous and smooth spectrum without overly spreading the radiation fan in the horizontal direction. As for the source size, the excursion of the positron beam caused by the wiggler field is given by +(K/{lambda})({lambda}{sub u}/2{pi}) = {plus_minus}7.8 {mu}m, which is negligible compared to the positron beam size in the horizontal direction. Thus, the positron beam completely defines the source size for Wiggler A. Wiggler A has the additional capability of varying the magnetic gap. This gives considerable flexibility to the users in changing its critical energy to lower values. For operation at large gap values, the device can also provide undulator radiation below 4 keV from the first harmonic.

  4. Specific Language Impairment Across Languages.

    PubMed

    Leonard, Laurence B

    2014-03-01

    Children with specific language impairment (SLI) have a significant and longstanding deficit in spoken language ability that adversely affects their social and academic well-being. Studies of children with SLI in a wide variety of languages reveal diverse symptoms, most of which seem to reflect weaknesses in grammatical computation and phonological short-term memory. The symptoms of the disorder are sensitive to the type of language being acquired, with extraordinary weaknesses seen in those areas of language that are relatively challenging for younger typically developing children. Although these children's deficits warrant clinical and educational attention, their weaknesses might reflect the extreme end of a language aptitude continuum rather than a distinct, separable condition. PMID:24765105

  5. Genetic specificity of face recognition

    PubMed Central

    Shakeshaft, Nicholas G.; Plomin, Robert

    2015-01-01

    Specific cognitive abilities in diverse domains are typically found to be highly heritable and substantially correlated with general cognitive ability (g), both phenotypically and genetically. Recent twin studies have found the ability to memorize and recognize faces to be an exception, being similarly heritable but phenotypically substantially uncorrelated both with g and with general object recognition. However, the genetic relationships between face recognition and other abilities (the extent to which they share a common genetic etiology) cannot be determined from phenotypic associations. In this, to our knowledge, first study of the genetic associations between face recognition and other domains, 2,000 18- and 19-year-old United Kingdom twins completed tests assessing their face recognition, object recognition, and general cognitive abilities. Results confirmed the substantial heritability of face recognition (61%), and multivariate genetic analyses found that most of this genetic influence is unique and not shared with other cognitive abilities. PMID:26417086

  6. DETERMINATION OF SPECIFIC NEUTRONIC REACTIVITY

    DOEpatents

    Dessauer, G.

    1960-05-10

    A method is given for production-line determination of the specific neutronic reactivity of such objects as individual nuclear fuel or neutron absorber elements and is notable for rapidity and apparatus simplicity. The object is incorporated in a slightly sub-critical chain fission reactive assembly having a discrete neutron source, thereby establishing a K/sub eff/ within the crucial range of 0.95 to 0.995. The range was found to afford, uniquely, flux- transient damped response in a niatter of seconds simultaneously with acceptable analytical sensitivity. The resulting neutron flux measured at a situs spaced from both object and source within the assembly serves as a calibrable indication of said reactivity.

  7. Specific test and evaluation plan

    SciTech Connect

    Hays, W.H.

    1998-03-20

    The purpose of this Specific Test and Evaluation Plan (STEP) is to provide a detailed written plan for the systematic testing of modifications made to the 241-AX-B Valve Pit by the W-314 Project. The STEP develops the outline for test procedures that verify the system`s performance to the established Project design criteria. The STEP is a lower tier document based on the W-314 Test and Evaluation Plan (TEP). Testing includes Validations and Verifications (e.g., Commercial Grade Item Dedication activities), Factory Acceptance Tests (FATs), installation tests and inspections, Construction Acceptance Tests (CATs), Acceptance Test Procedures (ATPs), Pre-Operational Test Procedures (POTPs), and Operational Test Procedures (OTPs). It should be noted that POTPs are not required for testing of the transfer line addition. The STEP will be utilized in conjunction with the TEP for verification and validation.

  8. Molecular-specific urokinase antibodies

    NASA Technical Reports Server (NTRS)

    Atassi, M. Zouhair (Inventor); Morrison, Dennis R. (Inventor)

    2009-01-01

    Antibodies have been developed against the different molecular forms of urokinase using synthetic peptides as immunogens. The peptides were synthesized specifically to represent those regions of the urokinase molecules which are exposed in the three-dimensional configuration of the molecule and are uniquely homologous to urokinase. Antibodies are directed against the lysine 158-isoleucine 159 peptide bond which is cleaved during activation from the single-chain (ScuPA) form to the bioactive double chain (54 KDa and 33 KDa) forms of urokinase and against the lysine 135 lysine 136 bond that is cleaved in the process of removing the alpha-chain from the 54 KDa form to produce the 33 KDa form of urokinase. These antibodies enable the direct measurement of the different molecular forms of urokinase from small samples of conditioned medium harvested from cell cultures.

  9. Random Field effects in perpendicular-anisotropy multilayer films

    NASA Astrophysics Data System (ADS)

    Xu, Jian; Silevitch, Daniel; Rosenbaum, Thomas

    With the application of a magnetic field transverse to the magnetic easy axis, randomly-distributed 3D collections of dipole-coupled Ising spins form a realization of the Random-Field Ising Model. Tuning the strength of the site-specific random field, and hence the disorder, via the applied transverse field regulates the domain reversal energetics and hence the macroscopic hysteresis loop. We extend this approach to two dimensions, using sputtered Perpendicular Magnetic Anisotropy (PMA) Co/Pt multilayer thin films. We characterize the coercive fields and hysteresis loops at a series of temperatures and transverse fields.

  10. Preferential axisymmetric field growth in kinematic geodynamo models

    NASA Astrophysics Data System (ADS)

    Livermore, Philip W.; Jackson, Andrew

    2004-11-01

    Earth's magnetic field, generated by fluid motion and inductive processes in Earth's core, has a predominantly axisymmetric dipolar component. Yet indefinite self-excitation of purely axisymmetric fields through any dynamo mechanism is specifically disallowed, begging the question of why the geodynamo sustains this dominant axisymmetric component. By considering a number of different fluid flow models modified from existing studies, we show that axisymmetric fields are consistently the most easily regenerated magnetic fields on short timescales, despite the fact that on long timescales they must die away. We argue that this transient field generation may play an important role in generating Earth's magnetic field, especially in the recovery after reversals.

  11. NFHS Court and Field Diagram Guide.

    ERIC Educational Resources Information Center

    Gillis, John, Ed.

    This guide contains a comprehensive collection of diagrams and specifications of playing fields and courts used in interscholastic and recreational sports, along with information on how to set up various formats of tournament drawings, how to compute golf handicaps, and how to convert metric-to-English distances. Lists are provided of national…

  12. Digital servo control of random sound fields

    NASA Technical Reports Server (NTRS)

    Nakich, R. B.

    1973-01-01

    It is necessary to place number of sensors at different positions in sound field to determine actual sound intensities to which test object is subjected. It is possible to determine whether specification is being met adequately or exceeded. Since excitation is of random nature, signals are essentially coherent and it is impossible to obtain true average.

  13. Applied-field MPD thruster geometry effects

    NASA Technical Reports Server (NTRS)

    Myers, Roger M.

    1991-01-01

    Eight MPD thruster configurations were used to study the effects of applied-field strength, propellant, and facility pressure on thruster performance. Vacuum facility background pressures higher than about 0.12 Pa were found to significantly influence thruster performance and electrode power deposition. Thrust efficiency and specific impulse increased monotonically with increasing applied field strength. Both cathode and anode radii fundamentally influenced the efficiency-specific impulse relationship, while their lengths influenced only the magnitude of the applied magnetic field required to reach a given performance level. At a given specific impulse, large electrode radii result in lower efficiencies for the operating conditions studied. For all test conditions, anode power deposition was the largest efficiency loss, and represented between 50 percent and 80 percent of the input power. The fraction of the input power deposited into the anode decreased with increasing applied field and anode radius. The highest performance measured, 20 percent efficiency at 3700 seconds specific impulse, was obtained using hydrogen propellant.

  14. Digital enhancement of flow field images

    NASA Technical Reports Server (NTRS)

    Kudlinski, Robert A.; Park, Stephen K.

    1988-01-01

    Most photographs of experimentally generated fluid flow fields have inherently poor photographic quality, specifically low contrast. Thus, there is a need to establish a process for quickly and accurately enhancing these photographs to provide improved versions for physical interpretation, analysis, and publication. A sequence of digital image processing techniques which have been demonstrated to effectively enhance such photographs is described.

  15. Field Water Balance of Landfill Final Covers

    EPA Science Inventory

    Landfill covers are critical to waste containment, yet field performance of specific cover designs has not been well documented and seldom been compared in side-by-side testing. A study was conducted to assess the ability of landfill final covers to control percolation into unde...

  16. Formal specification of human-computer interfaces

    NASA Technical Reports Server (NTRS)

    Auernheimer, Brent

    1990-01-01

    A high-level formal specification of a human computer interface is described. Previous work is reviewed and the ASLAN specification language is described. Top-level specifications written in ASLAN for a library and a multiwindow interface are discussed.

  17. Specific Carbohydrate Diet: Does It Work?

    MedlinePlus

    ... Specific Carbohydrate Diet (SCD) Go Back The Specific Carbohydrate Diet (SCD) Email Print + Share There is no ... diet that has received attention is the Specific Carbohydrate Diet. This diet limits poorly digestible carbohydrates to ...

  18. Gauge fields in spintronics

    NASA Astrophysics Data System (ADS)

    Fujita, T.; Jalil, M. B. A.; Tan, S. G.; Murakami, S.

    2011-12-01

    We present an overview of gauge fields in spintronics, focusing on their origin and physical consequences. Important topics, such as the Berry gauge field associated with adiabatic quantum evolution as well as gauge fields arising from other non-adiabatic considerations, are discussed. We examine the appearance and effects of gauge fields across three spaces, namely real-space, momentum-space, and time, taking on a largely semiclassical approach. We seize the opportunity to study other "spin-like" systems, including graphene, topological insulators, magnonics, and photonics, which emphasize the ubiquity and importance of gauge fields. We aim to provide an intuitive and pedagogical insight into the role played by gauge fields in spin transport.

  19. Simulated workplace neutron fields

    NASA Astrophysics Data System (ADS)

    Lacoste, V.; Taylor, G.; Röttger, S.

    2011-12-01

    The use of simulated workplace neutron fields, which aim at replicating radiation fields at practical workplaces, is an alternative solution for the calibration of neutron dosemeters. They offer more appropriate calibration coefficients when the mean fluence-to-dose equivalent conversion coefficients of the simulated and practical fields are comparable. Intensive Monte Carlo modelling work has become quite indispensable for the design and/or the characterization of the produced mixed neutron/photon fields, and the use of Bonner sphere systems and proton recoil spectrometers is also mandatory for a reliable experimental determination of the neutron fluence energy distribution over the whole energy range. The establishment of a calibration capability with a simulated workplace neutron field is not an easy task; to date only few facilities are available as standard calibration fields.

  20. 3D field harmonics

    SciTech Connect

    Caspi, S.; Helm, M.; Laslett, L.J.

    1991-03-30

    We have developed an harmonic representation for the three dimensional field components within the windings of accelerator magnets. The form by which the field is presented is suitable for interfacing with other codes that make use of the 3D field components (particle tracking and stability). The field components can be calculated with high precision and reduced cup time at any location (r,{theta},z) inside the magnet bore. The same conductor geometry which is used to simulate line currents is also used in CAD with modifications more readily available. It is our hope that the format used here for magnetic fields can be used not only as a means of delivering fields but also as a way by which beam dynamics can suggest correction to the conductor geometry. 5 refs., 70 figs.