Science.gov

Sample records for optimized background rejection

  1. Background Rejection in the ARA Experiment

    NASA Astrophysics Data System (ADS)

    Pfendner, Carl

    2017-03-01

    The Askaryan Radio Array (ARA) is a radio frequency observatory under construction at the South Pole that is searching for ultrahigh energy neutrinos via the Askaryan effect. Thermal fluctuations currently dominate the trigger-level background for the observatory and anthropogenic sources also introduce a significant source of noise. By taking advantage of the observatory's regular geometry and the expected coincident nature of the RF signals arriving from neutrino-induced events, this background can be filtered efficiently. This contribution will discuss techniques developed for the ARA analyses to reject these thermal signals, to reject anthropogenic backgrounds, and to search for neutrino-induced particle showers in the Antarctic ice. The results of a search for neutrinos from GRBs using the prototype station using some of these techniques will be presented.

  2. Alpha Background Rejection in Bolometer Detectors

    NASA Astrophysics Data System (ADS)

    Deporzio, Nicholas; Cuore Collaboration

    This study presents the modification of bolometer detectors used in particle searches to veto or otherwise reject alpha radiation background and the statistical advantages of doing so. Several techniques are presented in detail - plastic film scintillator vetoes, metallic film ionization vetoes, and Cherenkov radiation vetoes. Plastic scintillator films are cooled to bolometer temperatures and bombarded with 1.4MeV to 6.0MeV alpha particles representative of documented detector background. Quantum dot based liquid scintillator is similarly bombarded to produce a background induced scintillation light. Photomultipliers detect this scintillation light and produce a veto signal. Layered metallic films of a primary metal, dielectric, and secondary metal, such as gold-polyethylene-gold films, are cooled to milli-kelvin temperatures and biased to produce a current signal veto when incident 1.4MeV to 6.0MeV alpha particles ionize conduction paths through the film. Calibration of veto signal to background energy is presented. These findings are extrapolated to quantify the statistical impact of such modifications to bolometer searches. Effects of these techniques on experiment duration and signal-background ratio are discussed.

  3. Alpha Background Rejection in Bolometer Detectors

    NASA Astrophysics Data System (ADS)

    Deporzio, Nicholas

    2016-03-01

    This study presents the modification of bolometer detectors used in particle searches to veto or otherwise reject alpha radiation background and the statistical advantages of doing so. Several techniques are presented in detail - plastic film scintillator vetoes, metallic film ionization vetoes, and scintillating bolometer vetoes. Plastic scintillator films are cooled to bolometer temperatures and bombarded with 1.4MeV to 6.0MeV alpha particles representative of documented detector background. Photomultipliers detect this scintillation light and produce a veto signal. Layered metallic films of a primary metal, dielectric, and secondary metal, such as gold-polyethylene-gold films, are cooled to milli-kelvin temperatures and biased to produce a current signal veto when incident 1.4MeV to 6.0MeV alpha particles ionize conduction paths through the film. Modified Zinc Molybdate Bolometers are used to produce scintillation light when stimulated by alpha background. Calibration of veto signal to background energy is presented. Results are used to quantify the statistical impact of such modifications on bolometer searches.

  4. Study of Background Rejection Systems for the IXO Mission.

    NASA Astrophysics Data System (ADS)

    Laurent, Philippe; Limousin, O.; Tatischeff, V.

    2009-01-01

    The scientific performances of the IXO mission will necessitate a very low detector background level. This will imply thorough background simulations, and efficient background rejection systems. It necessitates also a very good knowledge of the detectors to be shielded. In APC, Paris, and CEA, Saclay, we got experience on these activities by conceiving and optimising in parallel the high energy detector and the active and passive background rejection system of the Simbol-X mission. Considering that this work may be naturally extended to other X-ray missions, we have initiated with CNES a R&D project on the study of background rejection systems mainly in view the IXO project. We will detail this activity in the poster.

  5. Background rejection in NEXT using deep neural networks

    NASA Astrophysics Data System (ADS)

    Renner, J.; Farbin, A.; Muñoz Vidal, J.; Benlloch-Rodríguez, J. M.; Botas, A.; Ferrario, P.; Gómez-Cadenas, J. J.; Álvarez, V.; Azevedo, C. D. R.; Borges, F. I. G.; Cárcel, S.; Carrión, J. V.; Cebrián, S.; Cervera, A.; Conde, C. A. N.; Díaz, J.; Diesburg, M.; Esteve, R.; Fernandes, L. M. P.; Ferreira, A. L.; Freitas, E. D. C.; Goldschmidt, A.; González-Díaz, D.; Gutiérrez, R. M.; Hauptman, J.; Henriques, C. A. O.; Hernando Morata, J. A.; Herrero, V.; Jones, B.; Labarga, L.; Laing, A.; Lebrun, P.; Liubarsky, I.; López-March, N.; Lorca, D.; Losada, M.; Martín-Albo, J.; Martínez-Lema, G.; Martínez, A.; Monrabal, F.; Monteiro, C. M. B.; Mora, F. J.; Moutinho, L. M.; Nebot-Guinot, M.; Novella, P.; Nygren, D.; Palmeiro, B.; Para, A.; Pérez, J.; Querol, M.; Ripoll, L.; Rodríguez, J.; Santos, F. P.; dos Santos, J. M. F.; Serra, L.; Shuman, D.; Simón, A.; Sofka, C.; Sorel, M.; Toledo, J. F.; Torrent, J.; Tsamalaidze, Z.; Veloso, J. F. C. A.; White, J.; Webb, R.; Yahlali, N.; Yepes-Ramírez, H.

    2017-01-01

    We investigate the potential of using deep learning techniques to reject background events in searches for neutrinoless double beta decay with high pressure xenon time projection chambers capable of detailed track reconstruction. The differences in the topological signatures of background and signal events can be learned by deep neural networks via training over many thousands of events. These networks can then be used to classify further events as signal or background, providing an additional background rejection factor at an acceptable loss of efficiency. The networks trained in this study performed better than previous methods developed based on the use of the same topological signatures by a factor of 1.2 to 1.6, and there is potential for further improvement.

  6. Background rejection in NEXT using deep neural networks

    DOE PAGES

    Renner, J.; Farbin, A.; Vidal, J. Muñoz; ...

    2017-01-16

    Here, we investigate the potential of using deep learning techniques to reject background events in searches for neutrinoless double beta decay with high pressure xenon time projection chambers capable of detailed track reconstruction. The differences in the topological signatures of background and signal events can be learned by deep neural networks via training over many thousands of events. These networks can then be used to classify further events as signal or background, providing an additional background rejection factor at an acceptable loss of efficiency. The networks trained in this study performed better than previous methods developed based on the usemore » of the same topological signatures by a factor of 1.2 to 1.6, and there is potential for further improvement.« less

  7. Analysis techniques for background rejection at the Majorana Demonstrator

    SciTech Connect

    Cuestra, Clara; Rielage, Keith Robert; Elliott, Steven Ray; Xu, Wenqin; Goett, John Jerome III

    2015-06-11

    The MAJORANA Collaboration is constructing the MAJORANA DEMONSTRATOR, an ultra-low background, 40-kg modular HPGe detector array to search for neutrinoless double beta decay in 76Ge. In view of the next generation of tonne-scale Ge-based 0νββ-decay searches that will probe the neutrino mass scale in the inverted-hierarchy region, a major goal of the MAJORANA DEMONSTRATOR is to demonstrate a path forward to achieving a background rate at or below 1 count/tonne/year in the 4 keV region of interest around the Q-value at 2039 keV. The background rejection techniques to be applied to the data include cuts based on data reduction, pulse shape analysis, event coincidences, and time correlations. The Point Contact design of the DEMONSTRATOR's germanium detectors allows for significant reduction of gamma background.

  8. Analysis techniques for background rejection at the MAJORANA DEMONSTRATOR

    SciTech Connect

    Cuesta, C; Abgrall, N.; Arnquist, I. J.; Avignone, III, F. T.; Barabash, A.S.; Bertrand, F. E.; Bradley, A. W.; Brudanin, V.; Busch, M.; Byram, D.; Caldwell, A. S.; Chan, Y-D; Christofferson, C. D.; Detwiler, J. A.; Efremenko, Yu.; Ejiri, H.; Elliott, S. R.; Galindo-Uribarri, A.; Gilliss, T.; Green, M. P.; Gruszko, J; Guinn, I S; Guiseppe, V E; Henning, R.; Howard, S.; Howe, M. A.; Keeter, K.J.; Kidd, M. F.; Konovalov, S.I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J.; MacMullin, J.; Meijer, S. J.; Orrell, J. L.; O'Shaughnessy, C.; Radford, D. C.; Rager, J.; Robertson, R.G.H.; Romero-Romero, E.; Snyder, N; Suriano, A. M.; Tedeschi, D; Trimble, J. E.; Vasilyev, S.; Vetter, K. [University of California et al.

    2015-01-01

    The MAJORANA Collaboration is constructing the MAJORANA DEMONSTRATOR, an ultra-low background, 40-kg modular HPGe detector array to search for neutrinoless double beta decay in Ge-76. In view of the next generation of tonne-scale Ge-based 0 nu beta beta-decay searches that will probe the neutrino mass scale in the inverted-hierarchy region, a major goal of the MAJORANA DEMONSTRATOR is to demonstrate a path forward to achieving a background rate at or below 1 count/tonne/year in the 4 keV region of interest around the Q-value at 2039 keV. The background rejection techniques to be applied to the data include cuts based on data reduction, pulse shape analysis, event coincidences, and time correlations. The Point Contact design of the DEMONSTRATOR's germanium detectors allows for significant reduction of gamma background.

  9. Analysis techniques for background rejection at the MAJORANA DEMONSTRATOR

    SciTech Connect

    Cuesta, C.; Buuck, M.; Detwiler, J. A.; Gruszko, J.; Guinn, I. S.; Leon, J.; Robertson, R. G. H.; Abgrall, N.; Bradley, A. W.; Chan, Y-D.; Mertens, S.; Poon, A. W. P.; Arnquist, I. J.; Hoppe, E. W.; Kouzes, R. T.; LaFerriere, B. D.; Orrell, J. L.; Avignone, F. T.; Baldenegro-Barrera, C. X.; Bertrand, F. E.; and others

    2015-08-17

    The MAJORANA Collaboration is constructing the MAJORANA DEMONSTRATOR, an ultra-low background, 40- kg modular HPGe detector array to search for neutrinoless double beta decay in {sup 76}Ge. In view of the next generation of tonne-scale Ge-based 0νβ β-decay searches that will probe the neutrino mass scale in the inverted-hierarchy region, a major goal of the MAJORANA DEMONSTRATOR is to demonstrate a path forward to achieving a background rate at or below 1 count/tonne/year in the 4 keV region of interest around the Q-value at 2039 keV. The background rejection techniques to be applied to the data include cuts based on data reduction, pulse shape analysis, event coincidences, and time correlations. The Point Contact design of the DEMONSTRATOR’s germanium detectors allows for significant reduction of gamma background.

  10. Optimal disturbance rejecting control of hyperbolic systems

    NASA Technical Reports Server (NTRS)

    Biswas, Saroj K.; Ahmed, N. U.

    1994-01-01

    Optimal regulation of hyperbolic systems in the presence of unknown disturbances is considered. Necessary conditions for determining the optimal control that tracks a desired trajectory in the presence of the worst possible perturbations are developed. The results also characterize the worst possible disturbance that the system will be able to tolerate before any degradation of the system performance. Numerical results on the control of a vibrating beam are presented.

  11. Physiologic Responses to Racial Rejection Images among Young Adults from African-American Backgrounds

    ERIC Educational Resources Information Center

    Kiang, Lisa; Blumenthal, Terry D.; Carlson, Erika N.; Lawson, Yolanda N.; Shell, J. Clark

    2009-01-01

    Physiologic reactivity to racially rejecting images was assessed in 35 young adults (10 males, 25 female) from African-American backgrounds using the startle probe paradigm. In a laboratory setting, participants viewed 16 images depicting racial rejection, racial acceptance, nonracial negative, and nonracial positive themes. While viewing these…

  12. Physiologic Responses to Racial Rejection Images among Young Adults from African-American Backgrounds

    ERIC Educational Resources Information Center

    Kiang, Lisa; Blumenthal, Terry D.; Carlson, Erika N.; Lawson, Yolanda N.; Shell, J. Clark

    2009-01-01

    Physiologic reactivity to racially rejecting images was assessed in 35 young adults (10 males, 25 female) from African-American backgrounds using the startle probe paradigm. In a laboratory setting, participants viewed 16 images depicting racial rejection, racial acceptance, nonracial negative, and nonracial positive themes. While viewing these…

  13. Film Vetoes for Alpha Background Rejection in Bolometer Detectors

    NASA Astrophysics Data System (ADS)

    Deporzio, Nicholas; Bucci, Carlo; Canonica, Lucia; Divacri, Marialaura; Cuore Collaboration; Absurd Team

    2015-04-01

    This study characterizes the effectiveness of encasing bolometer detectors in scintillator, metal ionization, and more exotic films to veto alpha radiation background. Bolometers are highly susceptible to alpha background and a successful veto should boost the statistical strength, speed, and signal-background ratio of bolometer particle searches. Plastic scintillator films are cooled to bolometer temperatures and bombarded with 1.4 MeV to 6.0 MeV alpha particles representative of detector conditions. Photomultipliers detect the keV range scintillation light and produce a veto signal. Also, layered films of a primary metal, dielectric, and secondary metal, such as gold-polyethylene-gold films, are cooled to milli-kelvin temperatures and biased with 0.1V to 100V to produce a current signal when incident 1.4 MeV to 6.0 MeV alpha particles ionize conduction paths through the film. Veto signals are characterized by their affect on bolometer detection of 865 keV target signals. Similar methods are applied to more exotic films. Early results show scintillator films raise target signal count rate and suppress counts above target energy by at least a factor of 10. This indicates scintillation vetoes are effective and that metal ionization and other films under study will also be effective.

  14. Background rejection of n+ surface events in GERDA Phase II

    NASA Astrophysics Data System (ADS)

    Lehnert, Björn

    2016-05-01

    The GERDA experiment searches for neutrinoless double beta (0vββ) decay in 76Ge using an array of high purity germanium (HPGe) detectors immersed in liquid argon (LAr). Phase II of the experiment uses 30 new broad energy germanium (BEGe) detectors with superior pulse shape discrimination capabilities compared to the previously used semi-coaxial detector design. By far the largest background component for BEGe detectors in GERDA are n+-surface events from 42K β decays which are intrinsic in LAr. The β particles with up to 3.5 MeV can traverse the 0.5 to 0.9 mm thick electrode and deposit energy within the region of interest for the 0vββ decay. However, those events have particular pulse shape features allowing for a strong discrimination. The understanding and simulation of this background, showing a reduction by up to a factor 145 with pulse shape discrimination alone, is presented in this work.

  15. Background rejection in the DMTPC dark matter search using charge signals

    NASA Astrophysics Data System (ADS)

    Lopez, J. P.; Dujmic, D.; Ahlen, S.; Battat, J. B. R.; Deaconu, C.; Fisher, P.; Henderson, S.; Inglis, A.; Kaboth, A.; Monroe, J.; Sciolla, G.; Tomita, H.; Wellenstein, H.; Yamamoto, R.

    2012-12-01

    The Dark Matter Time Projection Chamber (DMTPC) collaboration is developing a low pressure gas TPC for detecting Weakly Interacting Massive Particle (WIMP)-nucleon interactions. Optical readout with CCD cameras allows for the detection of the daily modulation of the direction of the dark matter wind. In order to reach sensitivities required for WIMP detection, the detector needs to minimize backgrounds from electron recoils. This paper demonstrates that a simplified CCD analysis achieves 7.3×10-5 rejection of electron recoils while a charge analysis yields an electron rejection factor of 3.3×10-4 for events with 241Am-equivalent ionization energy loss between 40 keV and 200 keV. A combined charge and CCD analysis yields a background-limited upper limit of 1.1×10-5 (90% confidence level) for the rejection of γ and electron events. Backgrounds from alpha decays from the field cage are eliminated by introducing a veto electrode that surrounds the sensitive region in the TPC. CCD-specific backgrounds are reduced more than two orders of magnitude when requiring a coincidence with the charge readout.

  16. Rejection of Alpha Surface Background in Non-scintillating Bolometric Detectors: The ABSuRD Project

    SciTech Connect

    Biassoni, M.; Brofferio, C.; Bucci, C.; Canonica, L.; di Vacri, M. L.; Gorla, P.; Pavan, M.; Yeh, M.

    2016-01-14

    Due to their excellent energy resolution values and the vast choice of possible materials, bolometric detectors are currently widely used in the physics of rare events. A limiting aspect for bolometers rises from their inability to discriminate among radiation types or surface from bulk events. It has been demonstrated that the main limitation to sensitivity for purely bolometric detectors is represented by surface alpha contaminations, causing a continuous background that cannot be discriminated. A new scintillation based technique for the rejection of surface alpha background in non- scintillating bolometric experiments is proposed in this work. The idea is to combine a scintillating and a high sensitivity photon detector with a non- scintillating absorber. Finally, we present results showing the possibility to reject events due to alpha decay at or nearby the surface of the crystal.

  17. Rejection of Alpha Surface Background in Non-scintillating Bolometric Detectors: The ABSuRD Project

    DOE PAGES

    Biassoni, M.; Brofferio, C.; Bucci, C.; ...

    2016-01-14

    Due to their excellent energy resolution values and the vast choice of possible materials, bolometric detectors are currently widely used in the physics of rare events. A limiting aspect for bolometers rises from their inability to discriminate among radiation types or surface from bulk events. It has been demonstrated that the main limitation to sensitivity for purely bolometric detectors is represented by surface alpha contaminations, causing a continuous background that cannot be discriminated. A new scintillation based technique for the rejection of surface alpha background in non- scintillating bolometric experiments is proposed in this work. The idea is to combinemore » a scintillating and a high sensitivity photon detector with a non- scintillating absorber. Finally, we present results showing the possibility to reject events due to alpha decay at or nearby the surface of the crystal.« less

  18. Rejection of Alpha Surface Background in Non-scintillating Bolometric Detectors: The ABSuRD Project

    NASA Astrophysics Data System (ADS)

    Biassoni, M.; Brofferio, C.; Bucci, C.; Canonica, L.; di Vacri, M. L.; Gorla, P.; Pavan, M.; Yeh, M.

    2016-08-01

    Due to their excellent energy resolution values and the vast choice of possible materials, bolometric detectors are currently widely used in the physics of rare events. A limiting aspect for bolometers rises from their inability to discriminate among radiation types or surface from bulk events. It has been demonstrated that the main limitation to sensitivity for purely bolometric detectors is represented by surface alpha contaminations, causing a continuous background that cannot be discriminated. A new scintillation-based technique for the rejection of surface alpha background in non-scintillating bolometric experiments is proposed in this work. The idea is to combine a scintillating and a high sensitivity photon detector with a non-scintillating absorber. We present results showing the possibility to reject events due to alpha decay at or nearby the surface of the crystal.

  19. Polonium-210 assay using a background-rejecting extractive liquid-scintillation method

    SciTech Connect

    Case, C.N.; McDowell, W.J.

    1981-01-01

    This paper describes a procedure which combines solvent extraction with alpha liquid scintillation spectrometry. Pulse shape discrimination electronics are used to reject beta and gamma pulses and to lower the background count to acceptable levels. Concentration of /sup 210/Po and separation from interferring elements are accomplished using a H/sub 3/Po/sub 4/-HCl solution with TOPO combined with a scintillor in toluene. (DLC)

  20. Pulse shape discrimination for background rejection in germanium gamma-ray detectors

    NASA Technical Reports Server (NTRS)

    Feffer, P. T.; Smith, D. M.; Campbell, R. D.; Primbsch, J. H.; Lin, R. P.

    1989-01-01

    A pulse-shape discrimination (PSD) technique is developed to reject the beta-decay background resulting from activation of Ge gamma-ray detectors by cosmic-ray secondaries. These beta decays are a major source of background at 0.2-2 MeV energies in well shielded Ge detector systems. The technique exploits the difference between the detected current pulse shapes of single- and multiple-site energy depositions within the detector: beta decays are primarily single-site events, while photons at these energies typically Compton scatter before being photoelectrically absorbed to produce multiple-site events. Depending upon the amount of background due to sources other than beta decay, PSD can more than double the detector sensitivity.

  1. Pulse shape discrimination for background rejection in germanium gamma-ray detectors

    NASA Technical Reports Server (NTRS)

    Feffer, P. T.; Smith, D. M.; Campbell, R. D.; Primbsch, J. H.; Lin, R. P.

    1989-01-01

    A pulse-shape discrimination (PSD) technique is developed to reject the beta-decay background resulting from activation of Ge gamma-ray detectors by cosmic-ray secondaries. These beta decays are a major source of background at 0.2-2 MeV energies in well shielded Ge detector systems. The technique exploits the difference between the detected current pulse shapes of single- and multiple-site energy depositions within the detector: beta decays are primarily single-site events, while photons at these energies typically Compton scatter before being photoelectrically absorbed to produce multiple-site events. Depending upon the amount of background due to sources other than beta decay, PSD can more than double the detector sensitivity.

  2. An intra-operative positron probe with background rejection capability for FDG-guided surgery.

    PubMed

    Yamamoto, Seiichi; Matsumoto, Keiichi; Sakamoto, Setsu; Tarutani, Kazumasa; Minato, Kotaro; Senda, Michio

    2005-02-01

    For radio-guided surgery on tumors using F-18-FDG, detection of annihilation gamma photons emanating from other parts of the body produces background radiation counts and limits its use in clinical situations. To overcome this limitation, we have developed an intra-operative positron probe with background-rejection capability. The positron probe uses a phoswich detector composed of a plastic scintillator and a bismuth germinate (BGO). A positron from a positron emitter such as F-18 is detected by the plastic scintillator and emits annihilation photons. The BGO detects one of the annihilation photons while a photo-multiplier tube (PMT) detects scintillation photons from both scintillators. The decay time differences of these two scintillators are used to distinguish whether the event is a true event where a positron and a following annihilation photon are detected simultaneously, or a background event. In this configuration, only positrons can be selectively detected, even in an environment of high background gamma photon flux. Spatial resolution was 11-mm full width at half maximum (FWHM) 5 mm from the detector surface. Measured sensitivity for the F-18 point source was 2.6 cps/kBq 5 mm from the detector surface. The background count rate was less than 0.5 cps for a 20-cm diameter cylindrical phantom containing 37 MBq of F-18 solution measured on the phantom surface, while the positron count rate was almost linear over a range of approximately 6 kcps. These results indicate that our developed intra-operative positron probe is valuable for radio-guided surgery on tumors using F-18-FDG in a high flux of background annihilation gamma photons.

  3. The Cryogenic Dark Matter Search and Background Rejection with Event Position Information

    SciTech Connect

    Wang, Gensheng

    2005-01-01

    Evidence from observational cosmology and astrophysics indicates that about one third of the universe is matter, but that the known baryonic matter only contributes to the universe at 4%. A large fraction of the universe is cold and non-baryonic matter, which has important role in the universe structure formation and its evolution. The leading candidate for the non-baryonic dark matter is Weakly Interacting Massive Particles (WIMPs), which naturally occurs in the supersymmetry theory in particle physics. The Cryogenic Dark Matter Search (CDMS) experiment is searching for evidence of a WIMP interaction off an atomic nucleus in crystals of Ge and Si by measuring simultaneously the phonon energy and ionization energy of the interaction in the CDMS detectors. The WIMP interaction energy is from a few keV to tens of keV with a rate less than 0.1 events/kg/day. To reach the goal of WIMP detection, the CDMS experiment has been conducted in the Soudan mine with an active muon veto and multistage passive background shields. The CDMS detectors have a low energy threshold and background rejection capabilities based on ionization yield. However, betas from contamination and other radioactive sources produce surface interactions, which have low ionization yield, comparable to that of bulk nuclear interactions. The low-ionization surface electron recoils must be removed in the WIMP search data analysis. An emphasis of this thesis is on developing the method of the surface-interaction rejection using location information of the interactions, phonon energy distributions and phonon timing parameters. The result of the CDMS Soudan run118 92.3 live day WIMP search data analysis is presented, and represents the most sensitive search yet performed.

  4. Distributed Optimization for a Class of Nonlinear Multiagent Systems With Disturbance Rejection.

    PubMed

    Wang, Xinghu; Hong, Yiguang; Ji, Haibo

    2016-07-01

    The paper studies the distributed optimization problem for a class of nonlinear multiagent systems in the presence of external disturbances. To solve the problem, we need to achieve the optimal multiagent consensus based on local cost function information and neighboring information and meanwhile to reject local disturbance signals modeled by an exogenous system. With convex analysis and the internal model approach, we propose a distributed optimization controller for heterogeneous and nonlinear agents in the form of continuous-time minimum-phase systems with unity relative degree. We prove that the proposed design can solve the exact optimization problem with rejecting disturbances.

  5. A New Background Rejection Technique for the Milagro Gamma-Ray Detector

    NASA Astrophysics Data System (ADS)

    Abdo, A. A.

    Milagro is a TeV gamma-ray detector that utilizes a large water Cherenkov detector to observe extensive air showers produced by high energy particles impacting the Earth's atmosphere. Milagro's distinct advantage compared to other TeV gamma-ray detectors is that it views a wide field (2 steradian over-head sky) and it continuously operates (>90% live time). A new background rejection technique that significantly increases the sensitivity of the Milagro detector has been developed. This technique improves the sensitivity of the Milagro detector by more than a factro of 2 over the previous technique (Atkins et al. 2003). This new /newtechnique differentiates between hadronic and gamma-ray showers by looking at the fundamental differences in the shower parameters between these two types of showers and how they register in the detector. These shower parameters include the number of Muons presented in the EAS, the size of the EAS, and some shower reconstruction parameters. This technique resulted in discoveries of localized TeV gamma-ray sources from the Galactic plane. Details of the new technique along with an all-sky TeV gamma-ray map --using this technique-- will be presented.

  6. Scanning thin-sheet laser imaging microscopy (sTSLIM) with structured illumination and HiLo background rejection.

    PubMed Central

    Schröter, Tobias J.; Johnson, Shane B.; John, Kerstin; Santi, Peter A.

    2011-01-01

    We report replacement of one side of a static illumination, dual sided, thin-sheet laser imaging microscope (TSLIM) with an intensity modulated laser scanner in order to implement structured illumination (SI) and HiLo image demodulation techniques for background rejection. The new system is equipped with one static and one scanned light-sheet and is called a scanning thin-sheet laser imaging microscope (sTSLIM). It is an optimized version of a light-sheet fluorescent microscope that is designed to image large specimens (<15 mm in diameter). In this paper we describe the hardware and software modifications to TSLIM that allow for static and uniform light-sheet illumination with SI and HiLo image demodulation. The static light-sheet has a thickness of 3.2 µm; whereas, the scanned side has a light-sheet thickness of 4.2 µm. The scanned side images specimens with subcellular resolution (<1 µm lateral and <4 µm axial resolution) with a size up to 15 mm. SI and HiLo produce superior contrast compared to both the uniform static and scanned light-sheets. HiLo contrast was greater than SI and is faster and more robust than SI because as it produces images in two-thirds of the time and exhibits fewer intensity streaking artifacts. PMID:22254177

  7. Background rejection method for tens of TeV gamma-ray astronomy applicable to wide angle timing arrays

    NASA Astrophysics Data System (ADS)

    Elshoukrofy, A. Sh M.; Postnikov, E. B.; Sveshnikova, L. G.

    2017-01-01

    A ‘knee-like’ approximation of Cherenkov light Lateral Distribution Functions, which we developed earlier, now is used for the actual tasks of background rejection methods for high energy (tens and hundreds of TeV) gamma-ray astronomy. In this work we implement this technique to the HiSCORE wide angle timing array consisting of Cherenkov light detectors with spacing of 100 m covering 0.2 km2 presently and up to 5 km2 in future. However, it can be applied to other similar arrays. We also show that the application of a multivariable approach (where 3 parameters of the knee-like approximation are used) allows us to reach a high level of background rejection, but it strongly depends on the number of hit detectors.

  8. Asymptotically optimal data analysis for rejecting local realism

    SciTech Connect

    Zhang, Yanbao; Glancy, Scott; Knill, Emanuel

    2011-12-15

    Reliable experimental demonstrations of violations of local realism are highly desirable for fundamental tests of quantum mechanics. One can quantify the violation witnessed by an experiment in terms of a statistical p value, which can be defined as the maximum probability according to local realism of a violation at least as high as that witnessed. Thus, high violation corresponds to small p value. We propose a prediction-based-ratio (PBR) analysis protocol whose p values are valid even if the prepared quantum state varies arbitrarily and local realistic models can depend on previous measurement settings and outcomes. It is therefore not subject to the memory loophole [J. Barrett et al., Phys. Rev. A 66, 042111 (2002)]. If the prepared state does not vary in time, the p values are asymptotically optimal. For comparison, we consider protocols derived from the number of standard deviations of violation of a Bell inequality and from martingale theory [R. Gill, e-print arXiv:quant-ph/0110137]. We find that the p values of the former can be too small and are therefore not statistically valid, while those derived from the latter are suboptimal. PBR p values do not require a predetermined Bell inequality and can be used to compare results from different tests of local realism independent of experimental details.

  9. Background rejection of TEXONO experiment to explore the sub-keV energy region with HPGe detector

    NASA Astrophysics Data System (ADS)

    Singh, M. K.; Sharma, V.; Singh, L.; Chen, J. H.; Singh, V.; Subrahmanyam, V. S.; Soma, A. K.; Wong, H. T.

    2017-10-01

    To observe the neutrino-nucleus coherent scattering as well as for dark matter search, a detection system with ultra-low energy high purity germanium detector has been set up by the TEXONO Collaboration in Kuo-Sheng Nuclear Power Plant. Owing to the weak nature and small recoil energy of these rare events, understanding of background sources and their contribution to the energy spectrum are the key factors in this experiment. In this report, we will focus in detail on the different sources of backgrounds in the TEXONO experiment and the techniques used to reject/minimize them.

  10. Development of a multivariate tool to reject background in a WZ diboson search for the CDF experiment

    SciTech Connect

    Cremonesi, Matteo

    2015-08-27

    In the frame of the strong on-going data analysis effort of the CDF collaboration at Fermilab, a method was developed by the candidate to improve the background rejection efficiency in the search for associated pair production of electroweak W, Z bosons. The performaces of the method for vetoing the tt background in a WZ/ZZ → fνq$\\bar{q}$ diboson search are reported. The method was developed in the inclusive 2-jets sample and applied to the “tag-2 jets" region, the subsample defined by the request that the two jets carry beauty flavor. In this region the tt production is one of the largest backgrounds. The tt veto proceeds in two steps: first, a set of pre-selection cuts are applied in a candidate sample where up to two leptons are accepted in addition to a jet pair, and the ZZ component of the signal is thus preserved; next, a Neural Network is trained to indicate the probability that the event be top-pair production. To validate the the method as developed in the inclusive 2-jets sample, it is applied to veto region providing a significant rejection of this important background.

  11. Background-Oriented Schlieren Pattern Optimization

    DTIC Science & Technology

    2011-12-01

    Orion Launch Abort Vehicle Wind Tunnel Model using Background-Oriented Schlieren”. volume AIAA 2010-1736. US Air Force Test and Evaluation Days, Nashville...1 1.2 System Description . . . . . . . . . . . . . . . . . . . . . 4 1.3 Existing Work...extensively been through trial and error and PIV particle size recommendations. 3 1.2 System Description The BOS technique is based on analyzing the

  12. Improved background rejection in neutrinoless double beta decay experiments using a magnetic field in a high pressure xenon TPC

    NASA Astrophysics Data System (ADS)

    Renner, J.; Cervera, A.; Hernando, J. A.; Imzaylov, A.; Monrabal, F.; Muñoz, J.; Nygren, D.; Gomez-Cadenas, J. J.

    2015-12-01

    We demonstrate that the application of an external magnetic field could lead to an improved background rejection in neutrinoless double-beta (0νββ) decay experiments using a high-pressure xenon (HPXe) TPC. HPXe chambers are capable of imaging electron tracks, a feature that enhances the separation between signal events (the two electrons emitted in the 0νββ decay of 136Xe) and background events, arising chiefly from single electrons of kinetic energy compatible with the end-point of the 0νββ decay (0Qββ). Applying an external magnetic field of sufficiently high intensity (in the range of 0.5-1 Tesla for operating pressures in the range of 5-15 atmospheres) causes the electrons to produce helical tracks. Assuming the tracks can be properly reconstructed, the sign of the curvature can be determined at several points along these tracks, and such information can be used to separate signal (0νββ) events containing two electrons producing a track with two different directions of curvature from background (single-electron) events producing a track that should spiral in a single direction. Due to electron multiple scattering, this strategy is not perfectly efficient on an event-by-event basis, but a statistical estimator can be constructed which can be used to reject background events by one order of magnitude at a moderate cost (about 30%) in signal efficiency. Combining this estimator with the excellent energy resolution and topological signature identification characteristic of the HPXe TPC, it is possible to reach a background rate of less than one count per ton-year of exposure. Such a low background rate is an essential feature of the next generation of 0νββ experiments, aiming to fully explore the inverse hierarchy of neutrino masses.

  13. A magnetic diverter for charged particle background rejection in the SIMBOL-X telescope

    NASA Astrophysics Data System (ADS)

    Spiga, D.; Fioretti, V.; Bulgarelli, A.; Dell'Orto, E.; Foschini, L.; Malaguti, G.; Pareschi, G.; Tagliaferri, G.; Tiengo, A.

    2008-07-01

    Minimization of charged particle background in X-ray telescopes is a well known issue. Charged particles (chiefly protons and electrons) naturally present in the cosmic environment constitute an important background source when they collide with the X-ray detector. Even worse, a serious degradation of spectroscopic performances of the X-ray detector was observed in Chandra and Newton-XMM, caused by soft protons with kinetic energies ranging between 100 keV and some MeV being collected by the grazing-incidence mirrors and funneled to the detector. For a focusing telescope like SIMBOL-X, the exposure of the soft X-ray detector to the proton flux can increase significantly the instrumental background, with a consequent loss of sensitivity. In the worst case, it can also seriously compromise the detector duration. A well-known countermeasure that can be adopted is the implementation of a properly-designed magnetic diverter, that should prevent high-energy particles from reaching the focal plane instruments of SIMBOL-X. Although Newton-XMM and Swift-XRT are equipped with magnetic diverters for electrons, the magnetic fields used are insufficient to effectively act on protons. In this paper, we simulate the behavior of a magnetic diverter for SIMBOL-X, consisting of commercially-available permanent magnets. The effects of SIMBOL-X optics is simulated through GEANT4 libraries, whereas the effect of the intense required magnetic fields is simulated along with specifically-written numerical codes in IDL.

  14. Acoustic studies for alpha background rejection in dark matter bubble chamber detectors

    SciTech Connect

    Bou-Cabo, M.; Felis, I.; Ardid, M.; Collaboration: COUPP Collaboration

    2013-08-08

    COUPP (Chicagoland Observatory for Underground Particle Physics) is an experiment with bubble chambers able to detect dark matter directly either with Spin-Dependent or with Spin-Independent interactions. The target material is a superheated liquid (usually CF3I) that can be bubble nucleated due to nuclear recoils produced by elastic collisions of dark matter particles. The bubble growth inside the chamber is accompanied with an acoustic signature. The acoustic technique has been successfully used to have a good alpha discrimination (about 99%). In this paper, we present different studies and results related with the characterization of the acoustic properties of the detector and the different phenomena involved in the acoustic measurements of the bubble growth, such as sound generation, sound transmission and optimization of piezoelectric transducers.

  15. Fast Vascular Ultrasound Imaging with Enhanced Spatial Resolution and Background Rejection.

    PubMed

    Bar-Zion, Avinoam; Tremblay-Darveau, Charles; Solomon, Oren; Adam, Dan; Eldar, Yonina

    2016-08-15

    Ultrasound super-localization microscopy techniques presented in the last few years enable non-invasive imaging of vascular structures at the capillary level by tracking the flow of ultrasound contrast agents (gas microbubbles). However, these techniques are currently limited by low temporal resolution and long acquisition times. Super-resolution optical fluctuation imaging (SOFI) is a fluorescence microscopy technique enabling sub-diffraction limit imaging with high temporal resolution by calculating high order statistics of the fluctuating optical signal. The aim of this work is to achieve fast acoustic imaging with enhanced resolution by applying the tools used in SOFI to contrast-enhance ultrasound (CEUS) plane-wave scans. The proposed method was tested using numerical simulations and evaluated using two in-vivo rabbit models: scans of healthy kidneys and VX-2 tumor xenografts. Improved spatial resolution was observed with a reduction of up to 50% in the full width half max of the point spread function. In addition, substantial reduction in the background level was achieved compared to standard mean amplitude persistence images, revealing small vascular structures within tumors. The scan duration of the proposed method is less than a second while current superlocalization techniques require acquisition duration of several minutes. As a result, the proposed technique may be used to obtain scans with enhanced spatial resolution and high temporal resolution, facilitating flow-dynamics monitoring. Our method can also be applied during a breath-hold, reducing the sensitivity to motion artifacts.

  16. Fast Vascular Ultrasound Imaging With Enhanced Spatial Resolution and Background Rejection.

    PubMed

    Bar-Zion, Avinoam; Tremblay-Darveau, Charles; Solomon, Oren; Adam, Dan; Eldar, Yonina C

    2017-01-01

    Ultrasound super-localization microscopy techniques presented in the last few years enable non-invasive imaging of vascular structures at the capillary level by tracking the flow of ultrasound contrast agents (gas microbubbles). However, these techniques are currently limited by low temporal resolution and long acquisition times. Super-resolution optical fluctuation imaging (SOFI) is a fluorescence microscopy technique enabling sub-diffraction limit imaging with high temporal resolution by calculating high order statistics of the fluctuating optical signal. The aim of this work is to achieve fast acoustic imaging with enhanced resolution by applying the tools used in SOFI to contrast-enhance ultrasound (CEUS) plane-wave scans. The proposed method was tested using numerical simulations and evaluated using two in-vivo rabbit models: scans of healthy kidneys and VX-2 tumor xenografts. Improved spatial resolution was observed with a reduction of up to 50% in the full width half max of the point spread function. In addition, substantial reduction in the background level was achieved compared to standard mean amplitude persistence images, revealing small vascular structures within tumors. The scan duration of the proposed method is less than a second while current super-localization techniques require acquisition duration of several minutes. As a result, the proposed technique may be used to obtain scans with enhanced spatial resolution and high temporal resolution, facilitating flow-dynamics monitoring. Our method can also be applied during a breath-hold, reducing the sensitivity to motion artifacts.

  17. Improved clipped periodic optimal control for semi-active harmonic disturbance rejection

    NASA Astrophysics Data System (ADS)

    Couillard, Maxime; Micheau, Philippe; Masson, Patrice

    2008-12-01

    This paper presents a new approach for harmonic disturbance rejection using semi-active vibration control. The approach is illustrated through application to the problem of maximizing the energy dissipated by a semi-active damper under harmonic excitation. In order to establish a baseline for the evaluation of the performance of the semi-active damper, the effectiveness of the optimal passive and active cases are first presented. The study then examines the ability of the clipped optimal control (or clipping control) approach to improve the energy dissipation capacity of the semi-active damper over the optimal passive damper. An approximate solution to the nonlinear dynamic problem, obtained using the method of averaging, and a time integration based numerical method indicate that this approach improves the energy dissipated by the semi-active damper over the optimal passive damper. The approach presented in this paper intends to further "improve", or "fine tune", the control parameters given by the clipped optimal control approach. This is done using an approximated solution of the problem and an appropriate optimization algorithm. Results clearly indicate that this new approach provides significant improvement on energy dissipation over the clipped optimal control approach for the semi-active damper.

  18. The faint limit of the Hubble Space Telescope faint object spectrograph and rejection of the cosmic-ray background

    NASA Technical Reports Server (NTRS)

    Tytler, David; Davis, Christopher

    1995-01-01

    The faintest object which can be observed with the Hubble Space Telescope (HST) Faint Object Spectrograph (FOS) is set by the detector cosmic-ray background and not by object flux. We use data from Beaver and Lyons to show that 48% of the background counts are from cosmic rays which each generate a near instantaneous burst of two or more counts. Setting the FOS threshold parameter REJLIM = 1, which rejects all frames with more than one count increases the ratio of signal-to-dark counts (S/D) by a factor of 1.94, regardless of the frame time or the object signal, because half of the dark counts which arrive in single counts (from either cosmic-ray bursts or thermal dark current photoemission) are rejected at the same rate as the object signal. But the signal-to-noise ratio (SNR proportional to S/square root of S + D) increases by at most a factor of 1.35, and for realistic parameters and taking into account dead time, we expect a gain in SNR of only 1.18. If a diode has failed and now emits noise, no data at all will be recorded. The chance of this occurring is approximately = 10% , and for this reason we do not recommend the use of REJLIM. The two-point correlation function of dark counts per pixel has strong peaks every four pixels, caused by the action of quarter-stepping on the counts from large bursts. The counts from such bursts spread over at least 80-100 diodes, and we show that such bursts can be rejected during data reduction if the data are recorded in RAPID mode with individual exposures of about 35 seconds. The SNR of the spectrum can also be improved by weighting each exposure by its SNR (a function ofthe mean dark count rate at that time), since dark varies by a factor of 2 around an orbit. These two procedures together increase the SNR by a factor of 1.1.3 (a 28% gain in exposure time) in regions of a spectrum where the object is much fainter than the background. We find that the Ly-alpha and O I sky emission lines give at most 4 (counts

  19. Nonlinear optimization-based device-free localization with outlier link rejection.

    PubMed

    Xiao, Wendong; Song, Biao; Yu, Xiting; Chen, Peiyuan

    2015-04-07

    Device-free localization (DFL) is an emerging wireless technique for estimating the location of target that does not have any attached electronic device. It has found extensive use in Smart City applications such as healthcare at home and hospitals, location-based services at smart spaces, city emergency response and infrastructure security. In DFL, wireless devices are used as sensors that can sense the target by transmitting and receiving wireless signals collaboratively. Many DFL systems are implemented based on received signal strength (RSS) measurements and the location of the target is estimated by detecting the changes of the RSS measurements of the wireless links. Due to the uncertainty of the wireless channel, certain links may be seriously polluted and result in erroneous detection. In this paper, we propose a novel nonlinear optimization approach with outlier link rejection (NOOLR) for RSS-based DFL. It consists of three key strategies, including: (1) affected link identification by differential RSS detection; (2) outlier link rejection via geometrical positional relationship among links; (3) target location estimation by formulating and solving a nonlinear optimization problem. Experimental results demonstrate that NOOLR is robust to the fluctuation of the wireless signals with superior localization accuracy compared with the existing Radio Tomographic Imaging (RTI) approach.

  20. Nonlinear Optimization-Based Device-Free Localization with Outlier Link Rejection

    PubMed Central

    Xiao, Wendong; Song, Biao; Yu, Xiting; Chen, Peiyuan

    2015-01-01

    Device-free localization (DFL) is an emerging wireless technique for estimating the location of target that does not have any attached electronic device. It has found extensive use in Smart City applications such as healthcare at home and hospitals, location-based services at smart spaces, city emergency response and infrastructure security. In DFL, wireless devices are used as sensors that can sense the target by transmitting and receiving wireless signals collaboratively. Many DFL systems are implemented based on received signal strength (RSS) measurements and the location of the target is estimated by detecting the changes of the RSS measurements of the wireless links. Due to the uncertainty of the wireless channel, certain links may be seriously polluted and result in erroneous detection. In this paper, we propose a novel nonlinear optimization approach with outlier link rejection (NOOLR) for RSS-based DFL. It consists of three key strategies, including: (1) affected link identification by differential RSS detection; (2) outlier link rejection via geometrical positional relationship among links; (3) target location estimation by formulating and solving a nonlinear optimization problem. Experimental results demonstrate that NOOLR is robust to the fluctuation of the wireless signals with superior localization accuracy compared with the existing Radio Tomographic Imaging (RTI) approach. PMID:25853406

  1. Disturbance rejection control for non-minimum phase systems with optimal disturbance observer.

    PubMed

    Wang, Lu; Su, Jianbo

    2015-07-01

    This paper investigates the disturbance rejection control for stable non-minimum phase (NMP) systems with time delay. A robust disturbance observer (DOB) based control structure is proposed. Specifically, the robust DOB is employed to compensate the uncertain plant into a nominal one, based on which a prefilter is adopted to acquire desired performance. Then, a novel DOB configuration strategy for stable NMP systems is proposed. This strategy synthesizes the internal and robust stability, relative order and mixed sensitivity design requirements together to establish the optimization function. The optimal solution is obtained by standard H∞ theory under the condition of guarantying the presented requirements. We also investigate how the DOB can compensate the uncertain plant into a nominal one. The specifical design procedure is presented for an uncertain plant with both unstable zeros and time delay.

  2. Evaluation of radioactive background rejection in 76Ge neutrino-lessdouble-beta decay experiments using a highly segmented HPGe detector

    SciTech Connect

    Chan, Yuen-Dat; Campbell, D.B.; Vetter, K.; Henning, R.; Lesko, K.; Chan, Y.D.; Poon, A.W.P.; Perry, M.; Hurley, D.; Smith, A.R.

    2007-02-05

    A highly segmented coaxial HPGe detector was operated in a low background counting facility for over 1 year to experimentally evaluate possible segmentation strategies for the proposed Majorana neutrino-less double-beta decay experiment. Segmentation schemes were evaluated on their ability to reject multi-segment events while retaining single-segment events. To quantify a segmentation scheme's acceptance efficiency the percentage of peak area due to single segment events was calculated for peaks located in the energy region 911-2614 keV. Single interaction site events were represented by the double-escape peak from the 2614 keV decay in {sup 208}Tl located at 1592 keV. In spite of its prototypical nature, the detector performed well under realistic operating conditions and required only minimal human interaction. Though the energy resolution for events with interactions in multiple segments was impacted by inter-segment cross-talk, the implementation of a cross-talk correlation matrix restored acceptable resolution. Additionally, simulations utilizing the MaGe simulation package were performed and found to be in good agreement with experimental observations verifying the external nature of the background radiation.

  3. NuLat: 3D Event Reconstruction of a ROL Detector for Neutrino Detection and Background Rejection

    NASA Astrophysics Data System (ADS)

    Yokley, Zachary; NuLat Collaboration

    2015-04-01

    NuLat is a proposed very-short baseline reactor antineutrino experiment that employs a unique detector design, a Ragahavan Optical Lattice (ROL), developed for the LENS solar neutrino experiment. The 3D lattice provides high spatial and temporal resolution and allows for energy deposition in each voxel to be determined independently of other voxels, as well as the time sequence associated with each voxel energy deposition. This unique feature arises from two independent means to spatially locate energy deposits: via timing and via optical channeling. NuLat, the first application of a ROL detector targeting physics results, will measure the reactor antineutrino flux at very short baselines via inverse beta decay (IBD). The ROL design of NuLat makes possible the reconstruction of positron energy with little contamination due to the annihilation gammas which smear the positron energy resolution in a traditional detector. IBD events are cleanly tagged via temporal and spatial coincidence of neutron capture in the vertex voxel or nearest neighbors. This talk will present work on IBD event reconstruction in NuLat and its likely impact on sterile neutrino detection via operation in higher background locations enabled by its superior rejection of backgrounds. This research has been funded in part by the National Science Foundation on Award Numbers 1001394 and 1001078.

  4. A nonlinear optimization approach for disturbance rejection in flexible space structures

    NASA Technical Reports Server (NTRS)

    Parlos, Alexander G.; Sunkel, John W.

    1990-01-01

    In this paper the design of an active control law for the rejection of persistent disturbances in large space structures is presented. The control system design approach is based on a deterministic model of the disturbances, with a model-based-compensator (MBC) structure, optimizing the magnitude of the disturbance that the structure can tolerate without violating certain predetermined constraints. In addition to closed-loop stability, the explicit treatment of state, control and control rate constraints, such as structural displacement, control actuator effort, and compensator time guarantees that the final design will exhibit desired performance characteristics. The technique is applied for the vibration damping of a simple two bay truss structure which is subjected to persistent disturbances, such as shuttle docking. Preliminary results indicate that the proposed control system can reject considerable persistent disturbances by utilizing most of the available control, while limiting the structural displacements to within desired tolerances. Further work, however, for incorporating additional design criteria, such as compensator robustness to be traded-off against performance specifications, is warranted.

  5. A nonlinear optimization approach for disturbance rejection in flexible space structures

    NASA Technical Reports Server (NTRS)

    Parlos, Alexander G.; Sunkel, John W.

    1990-01-01

    In this paper the design of an active control law for the rejection of persistent disturbances in large space structures is presented. The control system design approach is based on a deterministic model of the disturbances, with a model-based-compensator (MBC) structure, optimizing the magnitude of the disturbance that the structure can tolerate without violating certain predetermined constraints. In addition to closed-loop stability, the explicit treatment of state, control and control rate constraints, such as structural displacement, control actuator effort, and compensator time guarantees that the final design will exhibit desired performance characteristics. The technique is applied for the vibration damping of a simple two bay truss structure which is subjected to persistent disturbances, such as shuttle docking. Preliminary results indicate that the proposed control system can reject considerable persistent disturbances by utilizing most of the available control, while limiting the structural displacements to within desired tolerances. Further work, however, for incorporating additional design criteria, such as compensator robustness to be traded-off against performance specifications, is warranted.

  6. An improved sensitive assay for polonium-210 by use of a background-rejecting extractive liquid-scintillation method.

    PubMed

    Case, G N; McDowell, W J

    1982-10-01

    A procedure is described for the determination of polonium-210 in various types of materials, including ores, mill tailings, and environmental samples, by a combined solvent-extraction liquid-scintillation spectrometry method. Concentration of polonium-210 and separation from interfering elements (such as iron) are accomplished by extraction from a 7M phosphoric acid-0.01M hydrochloric acid solution with 0.20M trioctylphosphine oxide solution (together with a scintillator) in toluene. The polonium-210 is determined by counting the 5.3-MeV alpha-radiation with a photon/ electron-rejecting alpha liquid-scintillation spectrometer. Extraction coefficients of over 1000 for polonium ensure quantitative recovery, and no other alpha-emitters in the decay chains of uranium-238, uranium-235 and thorium-232 are extracted. The results for several samples show the relative standard deviation to be approximately 1.2%. A lower limit of detection of 0.0038 pCi is proposed, based on a counting time of 1000 min and an easily obtainable background of 0.01 cpm for the alpha peak.

  7. Neural dynamic optimization for control systems. I. Background.

    PubMed

    Seong, C Y; Widrow, B

    2001-01-01

    The paper presents neural dynamic optimization (NDO) as a method of optimal feedback control for nonlinear multi-input-multi-output (MIMO) systems. The main feature of NDO is that it enables neural networks to approximate the optimal feedback solution whose existence dynamic programming (DP) justifies, thereby reducing the complexities of computation and storage problems of the classical methods such as DP. This paper mainly describes the background and motivations for the development of NDO, while the two other subsequent papers of this topic present the theory of NDO and demonstrate the method with several applications including control of autonomous vehicles and of a robot arm, respectively.

  8. Optimal redistribution of the background ozone monitoring stations over France

    NASA Astrophysics Data System (ADS)

    Wu, Lin; Bocquet, Marc

    2011-01-01

    Ozone is a harmful air pollutant at ground level, and its concentrations are routinely measured with monitoring networks. The network design problem aims at determining the optimal positioning of the monitoring stations. In this study, the background stations of the French routine pollution monitoring network (BDQA) are partially redistributed over France under a set of design objectives. These background stations report ozone variations at large spatial scale comparable with that of a chemistry-transport model (CTM). The design criterion needs to be defined on a regular grid that covers France, where in general no ozone observations are available for validation. Geostatistical ozone estimation methods are used to extrapolate concentrations to these grid nodes. The geostatistical criteria are introduced to minimize the theoretical error of those geostatistical extrapolations. A physical criterion is also introduced to measure the ability of a network to represent a physical ozone field retrieved from CTM simulations using geostatistical extrapolation methods. A third type of criteria of geometrical nature, e.g. a maximal coverage of the design domain, are based uniquely on the distance between the network stations. To complete the network design methodology, a stochastic optimization method, simulated annealing, is employed in the algorithm to select optimally the stations. Significant improvement with all the proposed criteria has been found for the optimally redistributed network against the original background BDQA network. For instance, the relative improvements in the physical criterion value range from 21% to 32% compared to randomly relocated networks. Different design criteria lead to different optimally relocated networks. The optimal networks under physical criteria are the most heterogeneously distributed. More background stations are displaced to the coast, frontiers, and large urban agglomerations, e.g. Paris and Marseilles. The ozone heterogeneous

  9. Simplified analysis and optimization of space base and space shuttle heat rejection systems

    NASA Technical Reports Server (NTRS)

    Wulff, W.

    1972-01-01

    A simplified radiator system analysis was performed to predict steady state radiator system performance. The system performance was found to be describable in terms of five non-dimensional system parameters. The governing differential equations are integrated numerically to yield the enthalpy rejection for the coolant fluid. The simplified analysis was extended to produce the derivatives of the coolant exit temperature with respect to the governing system parameters. A procedure was developed to find the optimum set of system parameters which yields the lowest possible coolant exit temperature for either a given projected area or a given total mass. The process can be inverted to yield either the minimum area or the minimum mass, together with the optimum geometry, for a specified heat rejection rate.

  10. Monte Carlo optimization of sample dimensions of an 241Am Be source-based PGNAA setup for water rejects analysis

    NASA Astrophysics Data System (ADS)

    Idiri, Z.; Mazrou, H.; Beddek, S.; Amokrane, A.; Azbouche, A.

    2007-07-01

    The present paper describes the optimization of sample dimensions of a 241Am-Be neutron source-based Prompt gamma neutron activation analysis (PGNAA) setup devoted for in situ environmental water rejects analysis. The optimal dimensions have been achieved following extensive Monte Carlo neutron flux calculations using MCNP5 computer code. A validation process has been performed for the proposed preliminary setup with measurements of thermal neutron flux by activation technique of indium foils, bare and with cadmium covered sheet. Sensitive calculations were subsequently performed to simulate real conditions of in situ analysis by determining thermal neutron flux perturbations in samples according to chlorine and organic matter concentrations changes. The desired optimal sample dimensions were finally achieved once established constraints regarding neutron damage to semi-conductor gamma detector, pulse pile-up, dead time and radiation hazards were fully met.

  11. S-PRIME Heat Transport and Heat Rejection Subsystems Design Optimization

    NASA Astrophysics Data System (ADS)

    Moriarty, Michael P.

    1994-07-01

    The purpose of this paper is to describe the design status of the Rocketdyne space power reactor, incore, multicell, evolutionary (S-PRIME) design of the heat transport and heat rejection subsystems. The basic design concept is similar to that described previously; however, several detail design changes have resulted from changes in requirements. Improved definition of the various loop components has evolved from the performance of various trade studies. Overall layouts of the subsystem have been completed and the majority of the components are ready for preliminary design. The design will provide for the safe and reliable cooling of the nuclear reactor in a proven lightweight configuration.

  12. Background rejection capabilities of a Compton imaging telescope setup with a DSSD Ge planar detector and AGATA

    NASA Astrophysics Data System (ADS)

    Doncel, M.; Quintana, B.; Gadea, A.; Recchia, F.; Farnea, E.

    2011-08-01

    In this work, we show the first Monte Carlo results about the performance of the Ge array which we propose for the DESPEC experiment at FAIR, when the background algorithm developed for AGATA is applied. The main objective of our study is to characterize the capabilities of the γ-spectroscopy system, made up of AGATA detectors in a semi-spherical distribution covering a 1π solid angle and a set of planar Ge detectors in a daisy configuration, to discriminate between γ sources placed at different locations.

  13. Measurement of θ 13 in Double Chooz using neutron captures on hydrogen with novel background rejection techniques

    DOE PAGES

    Abe, Y.; Appel, S.; Abrahão, T.; ...

    2016-01-27

    We observed a measurement of the Double Chooz collaboration and the neutrino mixing angle θ13 using reactormore » $$\\bar{v}$$e via the inverse beta decay reaction in which the neutron is captured on hydrogen. Our measurement is based on 462.72 live days data, approximately twice as much data as in the previous such analysis, collected with a detector positioned at an average distance of 1050 m from two reactor cores. Several novel techniques have been developed to achieve significant reductions of the backgrounds and systematic uncertainties. Accidental coincidences, the dominant background in this analysis, are suppressed by more than an order of magnitude with respect to our previous publication by a multi-variate analysis. Furthermore, these improvements demonstrate the capability of precise measurement of reactor $$\\bar{v}$$e without gadolinium loading. Spectral distortions from the $$\\bar{v}$$e reactor flux predictions previously reported with the neutron capture on gadolinium events are confirmed in the independent data sample presented here. A value of sin2 2θ13= 0.0950.039+0.038 (stat+syst) is obtained from a fit to the observed event rate as a function of the reactor power, a method insensitive to the energy spectrum shape. A simultaneous fit of the hydrogen capture events and of the gadolinium capture events yields a measurement of sin2 2θ13 = 0.088 ± 0.033(stat+syst).« less

  14. Measurement of θ 13 in Double Chooz using neutron captures on hydrogen with novel background rejection techniques

    SciTech Connect

    Abe, Y.; Appel, S.; Abrahão, T.; Almazan, H.; Alt, C.; dos Anjos, J. C.; Barriere, J. C.; Baussan, E.; Bekman, I.; Bergevin, M.; Bezerra, T. J. C.; Bezrukov, L.; Blucher, E.; Brugière, T.; Buck, C.; Busenitz, J.; Cabrera, A.; Camilleri, L.; Carr, R.; Cerrada, M.; Chauveau, E.; Chimenti, P.; Collin, A. P.; Conrad, J. M.; Crespo-Anadón, J. I.; Crum, K.; Cucoanes, A. S.; Damon, E.; Dawson, J. V.; Dhooghe, J.; Dietrich, D.; Djurcic, Z.; Dracos, M.; Etenko, A.; Fallot, M.; von Feilitzsch, F.; Felde, J.; Fernandes, S. M.; Fischer, V.; Franco, D.; Franke, M.; Furuta, H.; Gil-Botella, I.; Giot, L.; Göger-Neff, M.; Gomez, H.; Gonzalez, L. F. G.; Goodenough, L.; Goodman, M. C.; Haag, N.; Hara, T.; Haser, J.; Hellwig, D.; Hofmann, M.; Horton-Smith, G. A.; Hourlier, A.; Ishitsuka, M.; Jochum, J.; Jollet, C.; Kaether, F.; Kalousis, L. N.; Kamyshkov, Y.; Kaneda, M.; Kaplan, D. M.; Kawasaki, T.; Kemp, E.; de Kerret, H.; Kryn, D.; Kuze, M.; Lachenmaier, T.; Lane, C. E.; Lasserre, T.; Letourneau, A.; Lhuillier, D.; Lima, H. P.; Lindner, M.; López-Castaño, J. M.; LoSecco, J. M.; Lubsandorzhiev, B.; Lucht, S.; Maeda, J.; Mariani, C.; Maricic, J.; Martino, J.; Matsubara, T.; Mention, G.; Meregaglia, A.; Miletic, T.; Milincic, R.; Minotti, A.; Nagasaka, Y.; Navas-Nicolás, D.; Novella, P.; Oberauer, L.; Obolensky, M.; Onillon, A.; Osborn, A.; Palomares, C.; Pepe, I. M.; Perasso, S.; Porta, A.; Pronost, G.; Reichenbacher, J.; Reinhold, B.; Röhling, M.; Roncin, R.; Rybolt, B.; Sakamoto, Y.; Santorelli, R.; Schilithz, A. C.; Schönert, S.; Schoppmann, S.; Shaevitz, M. H.; Sharankova, R.; Shrestha, D.; Sibille, V.; Sinev, V.; Skorokhvatov, M.; Smith, E.; Soiron, M.; Spitz, J.; Stahl, A.; Stancu, I.; Stokes, L. F. F.; Strait, M.; Suekane, F.; Sukhotin, S.; Sumiyoshi, T.; Sun, Y.; Svoboda, R.; Terao, K.; Tonazzo, A.; Thi, H. H. Trinh; Valdiviesso, G.; Vassilopoulos, N.; Veyssiere, C.; Vivier, M.; Wagner, S.; Walsh, N.; Watanabe, H.; Wiebusch, C.; Wurm, M.; Yang, G.; Yermia, F.; Zimmer, V.

    2016-01-27

    We observed a measurement of the Double Chooz collaboration and the neutrino mixing angle θ13 using reactor $\\bar{v}$e via the inverse beta decay reaction in which the neutron is captured on hydrogen. Our measurement is based on 462.72 live days data, approximately twice as much data as in the previous such analysis, collected with a detector positioned at an average distance of 1050 m from two reactor cores. Several novel techniques have been developed to achieve significant reductions of the backgrounds and systematic uncertainties. Accidental coincidences, the dominant background in this analysis, are suppressed by more than an order of magnitude with respect to our previous publication by a multi-variate analysis. Furthermore, these improvements demonstrate the capability of precise measurement of reactor $\\bar{v}$e without gadolinium loading. Spectral distortions from the $\\bar{v}$e reactor flux predictions previously reported with the neutron capture on gadolinium events are confirmed in the independent data sample presented here. A value of sin213= 0.0950.039+0.038 (stat+syst) is obtained from a fit to the observed event rate as a function of the reactor power, a method insensitive to the energy spectrum shape. A simultaneous fit of the hydrogen capture events and of the gadolinium capture events yields a measurement of sin213 = 0.088 ± 0.033(stat+syst).

  15. Bayesian signal processing of pulse shapes for background rejection in the Majorana Demonstrator

    NASA Astrophysics Data System (ADS)

    Shanks, Benjamin; Majorana Collaboration

    2015-10-01

    The Majorana Demonstrator uses high purity germanium (HPGe) detectors in the p-type point contact (PPC) geometry to search for neutrinoless double-beta decay (0 νββ) in 76Ge. Due to the unique electric potential created within the PPC geometry, the detailed pulse shape depends on the number of energy depositions contained within a given event. Pulse shape analysis (PSA) techniques can be used to estimate the number of separate depositions which combine to form a single pulse. This information can be used to discriminate between 0 νββ candidate events, which deposit energy at a single detector site, and gamma ray background, which can scatter and deposit energy in multiple locations. The problem of determining whether a pulse is single- or multi-site is well suited to Bayesian classifiers. Once trained via supervised machine learning, these algorithms can perform nonlinear cuts against multi-site events using the estimated probability function as a discriminator. The Bayesian approach can also be naturally extended to incorporate a model of the physical process responsible for signal generation within the detector. Presented here is an overview of the Bayesian classifier developed for use on the Demonstrator. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, the Particle Astrophysics Program of the National Science Foundation, and the Sanford Underground Research Facility.

  16. Optimal Background Estimators in Single-Molecule FRET Microscopy.

    PubMed

    Preus, Søren; Hildebrandt, Lasse L; Birkedal, Victoria

    2016-09-20

    Single-molecule total internal reflection fluorescence (TIRF) microscopy constitutes an umbrella of powerful tools that facilitate direct observation of the biophysical properties, population heterogeneities, and interactions of single biomolecules without the need for ensemble synchronization. Due to the low signal/noise ratio in single-molecule TIRF microscopy experiments, it is important to determine the local background intensity, especially when the fluorescence intensity of the molecule is used quantitatively. Here we compare and evaluate the performance of different aperture-based background estimators used particularly in single-molecule Förster resonance energy transfer. We introduce the general concept of multiaperture signatures and use this technique to demonstrate how the choice of background can affect the measured fluorescence signal considerably. A new, to our knowledge, and simple background estimator is proposed, called the local statistical percentile (LSP). We show that the LSP background estimator performs as well as current background estimators at low molecular densities and significantly better in regions of high molecular densities. The LSP background estimator is thus suited for single-particle TIRF microscopy of dense biological samples in which the intensity itself is an observable of the technique. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  17. Tacrolimus in preventing transplant rejection in Chinese patients – optimizing use

    PubMed Central

    Li, Chuan-Jiang; Li, Liang

    2015-01-01

    Tacrolimus is a product of fermentation of Streptomyces, and belongs to the family of calcineurin inhibitors. It is a widely used immunosuppressive drug for preventing solid-organ transplant rejection. Compared to cyclosporine, tacrolimus has greater immunosuppressive potency and a lower incidence of side effects. It has been accepted as first-line treatment after liver and kidney transplantation. Tacrolimus has specific features in Chinese transplant patients; its in vivo pharmacokinetics, treatment regimen, dose and administration, and adverse-effect profile are influenced by multiple factors, such as genetics and the spectrum of primary diseases in the Chinese population. We reviewed the clinical experience of tacrolimus use in Chinese liver- and kidney-transplant patients, including the pharmacology of tacrolimus, the immunosuppressive effects of tacrolimus versus cyclosporine, effects of different factors on tacrolimus metabolism on Chinese patients, personalized medicine, clinical safety profile, and patient satisfaction and adherence. This article provides guidance for the rational and efficient use of tacrolimus in Chinese organ-transplant patients. PMID:25609922

  18. Computational and experimental platform for understanding and optimizing water flux and salt rejection in nanoporous membranes.

    SciTech Connect

    Rempe, Susan B.

    2010-09-01

    Affordable clean water is both a global and a national security issue as lack of it can cause death, disease, and international tension. Furthermore, efficient water filtration reduces the demand for energy, another national issue. The best current solution to clean water lies in reverse osmosis (RO) membranes that remove salts from water with applied pressure, but widely used polymeric membrane technology is energy intensive and produces water depleted in useful electrolytes. Furthermore incremental improvements, based on engineering solutions rather than new materials, have yielded only modest gains in performance over the last 25 years. We have pursued a creative and innovative new approach to membrane design and development for cheap desalination membranes by approaching the problem at the molecular level of pore design. Our inspiration comes from natural biological channels, which permit faster water transport than current reverse osmosis membranes and selectively pass healthy ions. Aiming for an order-of-magnitude improvement over mature polymer technology carries significant inherent risks. The success of our fundamental research effort lies in our exploiting, extending, and integrating recent advances by our team in theory, modeling, nano-fabrication and platform development. A combined theoretical and experimental platform has been developed to understand the interplay between water flux and ion rejection in precisely-defined nano-channels. Our innovative functionalization of solid state nanoporous membranes with organic protein-mimetic polymers achieves 3-fold improvement in water flux over commercial RO membranes and has yielded a pending patent and industrial interest. Our success has generated useful contributions to energy storage, nanoscience, and membrane technology research and development important for national health and prosperity.

  19. Multi-channel lock-in amplifier assisted femtosecond time-resolved fluorescence non-collinear optical parametric amplification spectroscopy with efficient rejection of superfluorescence background

    SciTech Connect

    Mao, Pengcheng; Wang, Zhuan; Dang, Wei; Weng, Yuxiang

    2015-12-15

    Superfluorescence appears as an intense background in femtosecond time-resolved fluorescence noncollinear optical parametric amplification spectroscopy, which severely interferes the reliable acquisition of the time-resolved fluorescence spectra especially for an optically dilute sample. Superfluorescence originates from the optical amplification of the vacuum quantum noise, which would be inevitably concomitant with the amplified fluorescence photons during the optical parametric amplification process. Here, we report the development of a femtosecond time-resolved fluorescence non-collinear optical parametric amplification spectrometer assisted with a 32-channel lock-in amplifier for efficient rejection of the superfluorescence background. With this spectrometer, the superfluorescence background signal can be significantly reduced to 1/300–1/100 when the seeding fluorescence is modulated. An integrated 32-bundle optical fiber is used as a linear array light receiver connected to 32 photodiodes in one-to-one mode, and the photodiodes are further coupled to a home-built 32-channel synchronous digital lock-in amplifier. As an implementation, time-resolved fluorescence spectra for rhodamine 6G dye in ethanol solution at an optically dilute concentration of 10{sup −5}M excited at 510 nm with an excitation intensity of 70 nJ/pulse have been successfully recorded, and the detection limit at a pump intensity of 60 μJ/pulse was determined as about 13 photons/pulse. Concentration dependent redshift starting at 30 ps after the excitation in time-resolved fluorescence spectra of this dye has also been observed, which can be attributed to the formation of the excimer at a higher concentration, while the blueshift in the earlier time within 10 ps is attributed to the solvation process.

  20. Multi-channel lock-in amplifier assisted femtosecond time-resolved fluorescence non-collinear optical parametric amplification spectroscopy with efficient rejection of superfluorescence background

    NASA Astrophysics Data System (ADS)

    Mao, Pengcheng; Wang, Zhuan; Dang, Wei; Weng, Yuxiang

    2015-12-01

    Superfluorescence appears as an intense background in femtosecond time-resolved fluorescence noncollinear optical parametric amplification spectroscopy, which severely interferes the reliable acquisition of the time-resolved fluorescence spectra especially for an optically dilute sample. Superfluorescence originates from the optical amplification of the vacuum quantum noise, which would be inevitably concomitant with the amplified fluorescence photons during the optical parametric amplification process. Here, we report the development of a femtosecond time-resolved fluorescence non-collinear optical parametric amplification spectrometer assisted with a 32-channel lock-in amplifier for efficient rejection of the superfluorescence background. With this spectrometer, the superfluorescence background signal can be significantly reduced to 1/300-1/100 when the seeding fluorescence is modulated. An integrated 32-bundle optical fiber is used as a linear array light receiver connected to 32 photodiodes in one-to-one mode, and the photodiodes are further coupled to a home-built 32-channel synchronous digital lock-in amplifier. As an implementation, time-resolved fluorescence spectra for rhodamine 6G dye in ethanol solution at an optically dilute concentration of 10-5M excited at 510 nm with an excitation intensity of 70 nJ/pulse have been successfully recorded, and the detection limit at a pump intensity of 60 μJ/pulse was determined as about 13 photons/pulse. Concentration dependent redshift starting at 30 ps after the excitation in time-resolved fluorescence spectra of this dye has also been observed, which can be attributed to the formation of the excimer at a higher concentration, while the blueshift in the earlier time within 10 ps is attributed to the solvation process.

  1. Optimization of two-phase thermophilic anaerobic digestion of biowaste for hydrogen and methane production through reject water recirculation.

    PubMed

    Cavinato, C; Bolzonella, D; Fatone, F; Cecchi, F; Pavan, P

    2011-09-01

    The optimization of a two-phase thermophilic anaerobic process treating biowaste for hydrogen and methane production was carried out at pilot scale using two stirred reactors (CSTRs) and without any physical/chemical pre-treatment of inoculum. During the experiment the hydrogen production at low hydraulic retention time (3d) was tested, both with and without reject water recirculation and at two organic loading rate (16 and 21 kgTVS/m3 d). The better yields were obtained with recirculation where the pH reached an optimal value (5.5) thanks to the buffering capacity of the recycle stream. The specific gas production of the first reactor was 51 l/kgVS(fed) and H2 content in biogas 37%. The mixture of gas obtained from the two reactors met the standards for the biohythane mix only when lower loading rate were applied to the first reactor, with a composition of 6.7% H2, 40.1% CO2 and 52.3% CH4 the overall SGP being 0.78 m3/kgVS(fed).

  2. Eigenvalue optimization against brake squeal: Symmetry, mathematical background and experiments

    NASA Astrophysics Data System (ADS)

    Spelsberg-Korspeter, Gottfried

    2012-09-01

    Brake squeal is still a challenge for design engineers and scientists. Due to cost reasons for the avoidance of brake noise only passive measures are meaningful for a broad industrial range. Many countermeasures against squeal are based on the introduction of damping, for example by using shims. In the literature on the modeling of brake squeal, the structural properties of the brake disc are most often not considered. It has however been shown analytically and experimentally that the stiffness properties of the disc are important and that splitting of double modes of the disc has a stabilizing effect. This knowledge can be used for structural optimization of brake rotors. The goal of this paper is to exploit the potential and to discuss some mathematical difficulties. Furthermore, experimental evidence for the relation of rotor asymmetry and squeal is given.

  3. Detection of TeV Gamma-Ray Emission from the Cygnus Region of the Galaxy with Milagro Using a New Background Rejection Technique

    SciTech Connect

    Abdo, A. A.

    2006-10-27

    Milagro is a TeV gamma-ray observatory that utilizes a large water Cherenkov detector to observe extensive air showers (EAS) produced by high energy particles impacting the Earth's atmosphere. Milagro's distinct advantage compared to other TeV gamma-ray detectors is that it views a wide field (2 steradian overhead sky) and it continuously operates (> 90% live time ). These factors give Milagro the potential for discovery of new sources with unknown positions and times, such as gamma-ray bursts, flaring AGNs, and observation of diffuse and extended sources like the Galactic plane or large supernova remnants. Here we present a new technique for improving background rejection in Milagro as well as a gamma-ray image of the Cygnus region at energies near 12.5 TeV. We report the detection of both an extended source and a large area of diffuse gamma-ray emission from this region of the galaxy. This new extended source has an extent of 0.32 {+-} 0.12 degrees and an integral flux above 12.5 TeV of (1.71 {+-} 0.24stat {+-} 0.34sys) x 10-13cm-2s-1 assuming a differential source spectrum of E-2.6. The best-fit location for the source is RA = 304.66 {+-} 0.13stat {+-} 0.25sys degrees and declination 36.96 {+-} 0.08stat {+-} 0.2sys degrees.

  4. Control design methods for floating wind turbines for optimal disturbance rejection

    NASA Astrophysics Data System (ADS)

    Lemmer, Frank; Schlipf, David; Cheng, Po Wen

    2016-09-01

    An analysis of the floating wind turbine as a multi-input-multi-output system investigating the effect of the control inputs on the system outputs is shown. These effects are compared to the ones of the disturbances from wind and waves in order to give insights for the selection of the control layout. The frequencies with the largest impact on the outputs due to limited effect of the controlled variables are identified. Finally, an optimal controller is designed as a benchmark and compared to a conventional PI-controller using only the rotor speed as input. Here, the previously found system properties, especially the difficulties to damp responses to wave excitation, are confirmed and verified through a spectral analysis with realistic environmental conditions. This comparison also assesses the quality of the employed simplified linear simulation model compared to the nonlinear model and shows that such an efficient frequency-domain evaluation for control design is feasible.

  5. Optimal rejection of multiplicative noise via adaptive shrinkage of undecimated wavelet coefficients

    NASA Astrophysics Data System (ADS)

    Alparone, Luciano; Anghele, Nicola; Argenti, Fabrizio

    2001-12-01

    In this paper speckle reduction is approached as a Wiener-like filtering performed in the wavelet domain by means of an adaptive shrinkage of the detail coefficients of an undecimated decomposition. The amplitude of each coefficient is divided by the variance ratio of the noisy coefficient to the noise-free one. All the above quantities are analytically calculated from the speckled image, the speckle variance, and the wavelet filters. On the test image Lenna corrupted by synthetic speckle, the proposed method outperforms Kuan's LLMMSE filtering by almost 3 dB SNR. Experiments carried out on true and synthetic speckled images demonstrate that the visual quality of the results is excellent in terms of both background smoothing and preservation of edge sharpness and textures. The absence of decimation in the wavelet decomposition avoids the typical ringing impairments produced by critically-subsampled wavelet-based denoising.

  6. Reject analysis in direct digital radiography.

    PubMed

    Andersen, Eivind Richter; Jorde, Jannike; Taoussi, Nadia; Yaqoob, Sadia Halima; Konst, Bente; Seierstad, Therese

    2012-03-01

    Reject analysis can be used as a quality indicator, and is an important tool in localizing areas where optimization is required. Reducing number of rejects is important yielding reduced patient exposure and increased cost-effectiveness. To determine rejection rates and causes in direct digital radiography. Data were collected during a three-month period in spring 2010 at two direct digital laboratories in Norway. All X-ray examinations, types, numbers, and reasons for rejections were obtained using automatic reject analysis software. Thirteen causes for rejection could be selected. Out of the 27,284 acquired images, 3206 were rejected, yielding an overall rejection rate of 12%. Highest rejection rates were found for examination of knees, shoulders, and wrist. In all, 77% of the rejected images arose from positioning errors. An overall rejection rate of 12% indicates a need for optimizing radiographic practice in the department.

  7. Preventing Rejection

    MedlinePlus

    ... medications work best. These medications work in different phases of the immune response to minimize side effects ... effective immunosuppression. Clinical immunosuppression usually occurs in three phases: induction, maintenance and anti-rejection. Reference and Publication ...

  8. Rejected applications

    PubMed Central

    2014-01-01

    Objective: To review membership application materials (especially rejected applications) to the American Academy of Neurology (AAN) during its formative years (1947–1953). Methods: Detailed study of materials in the AAN Historical Collection. Results: The author identified 73 rejected applications. Rejected applicants (71 male, 2 female) lived in 25 states. The largest number was for the Associate membership category (49). These were individuals “in related fields who have made and are making contributions to the field of neurology.” By contrast, few applicants to Active membership or Fellowship status were rejected. The largest numbers of rejectees were neuropsychiatrists (19), neurosurgeons (16), and psychiatrists (14). Conclusion: The AAN, established in the late 1940s, was a small and politically vulnerable organization. A defining feature of the fledgling society was its inclusiveness; its membership was less restrictive than that of the older American Neurological Association. At the same time, the society needed to preserve its core as a neurologic society rather than one of psychiatry or neurosurgery. Hence, the balance between inclusiveness and exclusive identity was a difficult one to maintain. The Associate membership category, more than any other, was at the heart of this issue of self-definition. Associate members were largely practitioners of psychiatry or neurosurgery. Their membership was a source of consternation and was to be carefully been held in check during these critical formative years. PMID:24944256

  9. Improved Fuzzy C-Means based Particle Swarm Optimization (PSO) initialization and outlier rejection with level set methods for MR brain image segmentation.

    PubMed

    Mekhmoukh, Abdenour; Mokrani, Karim

    2015-11-01

    In this paper, a new image segmentation method based on Particle Swarm Optimization (PSO) and outlier rejection combined with level set is proposed. A traditional approach to the segmentation of Magnetic Resonance (MR) images is the Fuzzy C-Means (FCM) clustering algorithm. The membership function of this conventional algorithm is sensitive to the outlier and does not integrate the spatial information in the image. The algorithm is very sensitive to noise and in-homogeneities in the image, moreover, it depends on cluster centers initialization. To improve the outlier rejection and to reduce the noise sensitivity of conventional FCM clustering algorithm, a novel extended FCM algorithm for image segmentation is presented. In general, in the FCM algorithm the initial cluster centers are chosen randomly, with the help of PSO algorithm the clusters centers are chosen optimally. Our algorithm takes also into consideration the spatial neighborhood information. These a priori are used in the cost function to be optimized. For MR images, the resulting fuzzy clustering is used to set the initial level set contour. The results confirm the effectiveness of the proposed algorithm. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  10. Optimal snake-based segmentation of a random luminance target on a spatially disjoint background

    NASA Astrophysics Data System (ADS)

    Germain, Olivier; Réfrégier, Philippe

    1996-11-01

    We describe a segmentation processor that is optimal for tracking the shape of a target with random white Gaussian intensity appearing on a random white Gaussian spatially disjoint background. This algorithm, based on an active contours model (snakes), consists of correlations of binary references with preprocessed versions of the scene image. This result can provide a practical method to adapt the reference image to correlation techniques.

  11. Optimal transmit phasing on tissue background suppression in contrast harmonic imaging.

    PubMed

    Shen, Che-Chou; Hsieh, Yi-Chun

    2008-11-01

    Ultrasonic harmonic imaging provides superior image quality than linear imaging and has become an important diagnostic tool in many clinical applications. Nevertheless, the contrast-to-tissue ratio (CTR) in harmonic imaging is generally limited by tissue background signal comprising both the leakage harmonic signal and the tissue harmonic signal. Harmonic leakage generally occurs when a wideband transmit pulse is used for better axial resolution. In addition, generation of tissue harmonic signal during acoustic propagation also decreases the CTR. In this paper, suppression of tissue background signal in harmonic imaging is studied by selecting an optimal phase of the transmit signal to achieve destructive cancellation between the tissue harmonic signal and the leakage harmonic signal. With the optimal suppression phase, our results indicate that the tissue signal can be significantly reduced at second harmonic band, whereas the harmonic amplitude from contrast agents shows negligible change with the selection of transmit phase. Consequently, about 5-dB CTR improvement can be achieved from effective reduction of tissue background amplitude in optimal transmit phasing.

  12. Optimized background reduction in low-level gamma-ray spectrometry at a surface laboratory.

    PubMed

    Hurtado, S; García-León, M; García-Tenorio, R

    2006-09-01

    The background of a coaxial Ge detector placed at a surface laboratory has been reduced by means of a background reduction setup consisting of a passive shield of low-activity lead, a simple radon suppression system and an active shield with a plastic scintillation plate. In particular, we have devoted our efforts to in-depth optimization of each parameter associated with different anticoincidence setups and to their subsequent intercomparison. The overall performance of the active shield was improved by using the optimum time parameters for each setup. The final objective is to decrease the cosmic-ray background and, by this way, to reduce the detection limits of gamma-ray spectrometers at conventional laboratories, and consequently make them competitive for different measurements like (210)Pb dating.

  13. The GLAST Background Model

    SciTech Connect

    Ormes, J. F.; Atwood, W.; Burnett, T.; Grove, E.; Longo, F.; McEnery, J.; Ritz, S.; Mizuno, T.

    2007-07-12

    In order to estimate the ability of the GLAST/LAT to reject unwanted background of charged particles, optimize the on-board processing, size the required telemetry and optimize the GLAST orbit, we developed a detailed model of the background particles that would affect the LAT. In addition to the well-known components of the cosmic radiation, we included splash and reentrant components of protons, electrons (e+ and e-) from 10 MeV and beyond as well as the albedo gamma rays produced by cosmic ray interactions with the atmosphere. We made estimates of the irreducible background components produced by positrons and hadrons interacting in the multilayered micrometeorite shield and spacecraft surrounding the LAT and note that because the orbital debris has increased, the shielding required and hence the background are larger than were present in EGRET. Improvements to the model are currently being made to include the east-west effect.

  14. The GLAST Background Model

    SciTech Connect

    Ormes, J.F.; Atwood, W.; Burnett, T.; Grove, E.; Longo, F.; McEnery, J.; Mizuno, T.; Ritz, S.; /NASA, Goddard

    2007-10-17

    In order to estimate the ability of the GLAST/LAT to reject unwanted background of charged particles, optimize the on-board processing, size the required telemetry and optimize the GLAST orbit, we developed a detailed model of the background particles that would affect the LAT. In addition to the well-known components of the cosmic radiation, we included splash and reentrant components of protons, electrons (e+ and e-) from 10 MeV and beyond as well as the albedo gamma rays produced by cosmic ray interactions with the atmosphere. We made estimates of the irreducible background components produced by positrons and hadrons interacting in the multilayered micrometeorite shield and spacecraft surrounding the LAT and note that because the orbital debris has increased, the shielding required and hence the background are larger than were present in EGRET. Improvements to the model are currently being made to include the east-west effect.

  15. Optimization of transition edge sensor arrays for cosmic microwave background observations with the south pole telescope

    DOE PAGES

    Ding, Junjia; Ade, P. A. R.; Anderson, A. J.; ...

    2016-12-15

    In this study, we describe the optimization of transition-edge-sensor (TES) detector arrays for the thirdgeneration camera for the South PoleTelescope.The camera,which contains ~16 000 detectors, will make high-angular-resolution maps of the temperature and polarization of the cosmic microwave background. Our key results are scatter in the transition temperature of Ti/Au TESs is reduced by fabricating the TESs on a thin Ti(5 nm)/Au(5 nm) buffer layer and the thermal conductivity of the legs that support our detector islands is dominated by the SiOx dielectric in the microstrip transmission lines that run along

  16. Optimization of low-background alpha spectrometers for analysis of thick samples.

    PubMed

    Misiaszek, M; Pelczar, K; Wójcik, M; Zuzel, G; Laubenstein, M

    2013-11-01

    Results of alpha spectrometric measurements performed deep underground and above ground with and without active veto show that the underground measurement of thick samples is the most sensitive method due to significant reduction of the muon-induced background. In addition, the polonium diffusion requires for some samples an appropriate selection of an energy region in the registered spectrum. On the basis of computer simulations the best counting conditions are selected for a thick lead sample in order to optimize the detection limit. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Optimization of transition edge sensor arrays for cosmic microwave background observations with the south pole telescope

    DOE PAGES

    Ding, Junjia; Ade, P. A. R.; Anderson, A. J.; ...

    2016-12-15

    In this study, we describe the optimization of transition-edge-sensor (TES) detector arrays for the thirdgeneration camera for the South PoleTelescope.The camera,which contains ~16 000 detectors, will make high-angular-resolution maps of the temperature and polarization of the cosmic microwave background. Our key results are scatter in the transition temperature of Ti/Au TESs is reduced by fabricating the TESs on a thin Ti(5 nm)/Au(5 nm) buffer layer and the thermal conductivity of the legs that support our detector islands is dominated by the SiOx dielectric in the microstrip transmission lines that run along

  18. Optimal Local Searching for Fast and Robust Textureless 3D Object Tracking in Highly Cluttered Backgrounds.

    PubMed

    Seo, Byung-Kuk; Park, Jong-Il; Hinterstoisser, Stefan; Ilic, Slobodan

    2013-06-13

    Edge-based tracking is a fast and plausible approach for textureless 3D object tracking, but its robustness is still very challenging in highly cluttered backgrounds due to numerous local minima. To overcome this problem, we propose a novel method for fast and robust textureless 3D object tracking in highly cluttered backgrounds. The proposed method is based on optimal local searching of 3D-2D correspondences between a known 3D object model and 2D scene edges in an image with heavy background clutter. In our searching scheme, searching regions are partitioned into three levels (interior, contour, and exterior) with respect to the previous object region, and confident searching directions are determined by evaluating candidates of correspondences on their region levels; thus, the correspondences are searched among likely candidates in only the confident directions instead of searching through all candidates. To ensure the confident searching direction, we also adopt the region appearance, which is efficiently modeled on a newly defined local space (called a searching bundle). Experimental results and performance evaluations demonstrate that our method fully supports fast and robust textureless 3D object tracking even in highly cluttered backgrounds.

  19. Optimal local searching for fast and robust textureless 3D object tracking in highly cluttered backgrounds.

    PubMed

    Seo, Byung-Kuk; Park, Hanhoon; Park, Jong-Il; Hinterstoisser, Stefan; Ilic, Slobodan

    2014-01-01

    Edge-based tracking is a fast and plausible approach for textureless 3D object tracking, but its robustness is still very challenging in highly cluttered backgrounds due to numerous local minima. To overcome this problem, we propose a novel method for fast and robust textureless 3D object tracking in highly cluttered backgrounds. The proposed method is based on optimal local searching of 3D-2D correspondences between a known 3D object model and 2D scene edges in an image with heavy background clutter. In our searching scheme, searching regions are partitioned into three levels (interior, contour, and exterior) with respect to the previous object region, and confident searching directions are determined by evaluating candidates of correspondences on their region levels; thus, the correspondences are searched among likely candidates in only the confident directions instead of searching through all candidates. To ensure the confident searching direction, we also adopt the region appearance, which is efficiently modeled on a newly defined local space (called a searching bundle). Experimental results and performance evaluations demonstrate that our method fully supports fast and robust textureless 3D object tracking even in highly cluttered backgrounds.

  20. Spectral anomaly methods for aerial detection using KUT nuisance rejection

    NASA Astrophysics Data System (ADS)

    Detwiler, R. S.; Pfund, D. M.; Myjak, M. J.; Kulisek, J. A.; Seifert, C. E.

    2015-06-01

    This work discusses the application and optimization of a spectral anomaly method for the real-time detection of gamma radiation sources from an aerial helicopter platform. Aerial detection presents several key challenges over ground-based detection. For one, larger and more rapid background fluctuations are typical due to higher speeds, larger field of view, and geographically induced background changes. As well, the possible large altitude or stand-off distance variations cause significant steps in background count rate as well as spectral changes due to increased gamma-ray scatter with detection at higher altitudes. The work here details the adaptation and optimization of the PNNL-developed algorithm Nuisance-Rejecting Spectral Comparison Ratios for Anomaly Detection (NSCRAD), a spectral anomaly method previously developed for ground-based applications, for an aerial platform. The algorithm has been optimized for two multi-detector systems; a NaI(Tl)-detector-based system and a CsI detector array. The optimization here details the adaptation of the spectral windows for a particular set of target sources to aerial detection and the tailoring for the specific detectors. As well, the methodology and results for background rejection methods optimized for the aerial gamma-ray detection using Potassium, Uranium and Thorium (KUT) nuisance rejection are shown. Results indicate that use of a realistic KUT nuisance rejection may eliminate metric rises due to background magnitude and spectral steps encountered in aerial detection due to altitude changes and geographically induced steps such as at land-water interfaces.

  1. Evaluating the Charged Background Rejection Requirement in an Experiment to Measure BR(K L → π0 νν -) at the CERN SPS

    NASA Astrophysics Data System (ADS)

    Bradley, A.

    2016-11-01

    Measuring the rate at which the long-lived, neutral kaon decays into a neutral pion, neutrino, and anti-neutrino allows physicists an opportunity to test precise predictions made by the Standard Model. Differences between theoretical predictions and experimental measurements may point to new physics. Not only does the Standard Model predict a very low probability at approximately 3 KL→ π0 νν -) decay in 100 billion KL decays, but many of the common decays leave false signals in the detector that look the same as the true signal. Charged decays have been studied to determine the required detection efficiency necessary to eliminate them. The conclusion of these studies is that a reduction by a factor of 1/(3 × 109) will be required to achieve the 10:1 signal to charged background ratio necessary for the experiment.

  2. [Selection of back-ground electrolyte in capillary zone electrophoresis by triangle and tetrahedron optimization methods].

    PubMed

    Sun, Guoxiang; Song, Wenjing; Lin, Ting

    2008-03-01

    The triangle and tetrahedron optimization methods were developed for the selection of back-ground electrolyte (BGE) in capillary zone electrophoresis (CZE). Chromatographic fingerprint index F and chromatographic fingerprint relative index F(r) were used as the objective functions for the evaluation, and the extract of Saussurea involucrate by water was used as the sample. The BGE was composed of borax, boric acid, dibasic sodium phosphate and sodium dihydrogen phosphate solution with different concentrations using triangle and tetrahedron optimization methods. Re-optimization was carried out by adding organic modifier to the BGE and adjusting the pH value. In triangle method, when 50 mmol/L borax-150 mmol/L sodium dihydrogen phosphate (containing 3% acetonitrile) (1 : 1, v/v) was used as BGE, the isolation was considered to be satisfactory. In tetrahedron method, the best BGE was 50 mmol/L borax-150 mmol/L sodium dihydrogen phosphate-200 mmol/L boric acid (1 : 1 : 2, v/v/v; adjusting the pH value to 8.55 by 0.1 mol/L sodium hydroxide). There were 28 peaks and 25 peaks under the different conditions respectively. The results showed that the methods could be applied to the selection of BGE in CZE of the extract of traditional Chinese medicine by water or ethanol.

  3. Design optimization and background modeling of the HEX experiment on Chandrayaan-I

    NASA Astrophysics Data System (ADS)

    Sudhakar, Manju; Sreekumar, P.

    2012-11-01

    Spacecraft and their subsystem components are subject to a very hazardous radiation environment in both near-Earth and deep space orbits. Knowledge of the effects of this high energy particle and electromagnetic radiation is essential in designing sensors, electronic circuits and living habitats for humans in near Earth orbit, en route to and on the Moon and Mars. This paper discusses the use of Monte Carlo simulations to optimize system design, radiation source modeling, and determination of background in sensors due to galactic cosmic rays and radiation from the Moon. The results demonstrate the use of Monte Carlo particle transport toolkits to predict secondary production, determine dose rates in space and design required shielding geometry.

  4. Optimizing an infrasound sensor network for measuring acoustic background noise and its inversion for stratospheric winds

    NASA Astrophysics Data System (ADS)

    Marcillo, O. E.; Arrowsmith, S.

    2013-12-01

    We demonstrate the design of an infrasound network (and the associated analysis) for measuring and inverting low-frequency acoustic background noise (microbaroms) for stratospheric winds. We developed a mathematical framework for the inversion of local stratospheric winds using microbaroms, and found theoretical constraints on the optimum sensor network topology. Based on these results, we deployed, over the winter months (January to March, 2013), a prototype sensor network comprising six infrasound stations separated between 5 and 70 km; the initial analysis shows periods of very high coherency (suitable for our inversion) lasting several hours with associated tropospheric and low stratospheric celerities. We are analyzing the coherency between signals with distance and relative azimuth. Following this pilot study, we are designing a denser sensor network further optimized to capture microbaroms and planning for its validation using independent measurements.

  5. Optimal cosmic microwave background map-making in the presence of cross-correlated noise

    NASA Astrophysics Data System (ADS)

    de Gasperis, G.; Buzzelli, A.; Cabella, P.; de Bernardis, P.; Vittorio, N.

    2016-08-01

    Aims: We present an extension of the ROMA map-making algorithm for the generation of optimal cosmic microwave background polarization maps. The new code allows for a possible cross-correlated noise component among the detectors of a CMB experiment. A promising application is the forthcoming LSPE balloon-borne experiment, which is devoted to the accurate observation of CMB polarization at large angular scales. Methods: We generalized the noise covariance matrix in time domain to account for all the off-diagonal terms due to the detector cross-talk. Hence, we performed preliminary forecasts of the LSPE-SWIPE instrument. Results: We found that considering the noise cross-correlation among the detectors results in a more realistic estimate of the angular power spectra. In particular, the extended ROMA algorithm has provided a considerable reduction of the spectra error bars. We expect that this improvement could be crucial in constraining the B-mode polarization at the largest scales.

  6. Optimal Lateral Guidance for Automatic Landing of a Lightweight High Altitude Long Endurance Unmanned Aerial System with Crosswind Rejection

    NASA Astrophysics Data System (ADS)

    Smith, Nathan Allen

    Unmanned aerial systems will be the dominant force in the aviation industry. Among these aircraft the use of high altitude long endurance unmanned aerial systems has increased dramatically. Based on the geometry of these types of aircraft the possible changing weather conditions during long flights poses many problems. These difficulties are compounded by the push towards fully autonomous systems. Large wingspan and, typically, small in-line landing gear make a landing in crosswind exceedingly difficult. This study uses a modified gain scheduling technique for optimizing the landing attitude for a generic vehicle based on geometry and crosswind speed. This is performed by directly utilizing the crosswind estimation to calculate a desired crab and roll angle that gives the lowest risk attitude for landing. An extended Kalman filter is developed that estimates the aircraft states as well as the 3D wind component acting on the aircraft. The aircraft used in this analysis is the DG808S, a large wingspan lightweight electric glider. The aircraft is modelled using Advanced Aircraft Analysis software and a six degree of freedom nonlinear simulation is implemented for testing. The controller used is a nonlinear model predictive controller. The simulations show that the extended Kalman filter is capable of estimating the crosswind and can therefore be used in the full aircraft simulation. Different crosswind settings are used which include both constant crosswind and gust conditions. Crosswind landing capabilities are increased by 35%. Deviation from the desired path in the cruise phase is reduced by up to 68% and time to path convergence is reduced by up to 53%.

  7. Effector Mechanisms of Rejection

    PubMed Central

    Moreau, Aurélie; Varey, Emilie; Anegon, Ignacio; Cuturi, Maria-Cristina

    2013-01-01

    Organ transplantation appears today to be the best alternative to replace the loss of vital organs induced by various diseases. Transplants can, however, also be rejected by the recipient. In this review, we provide an overview of the mechanisms and the cells/molecules involved in acute and chronic rejections. T cells and B cells mainly control the antigen-specific rejection and act either as effector, regulatory, or memory cells. On the other hand, nonspecific cells such as endothelial cells, NK cells, macrophages, or polymorphonuclear cells are also crucial actors of transplant rejection. Last, beyond cells, the high contribution of antibodies, chemokines, and complement molecules in graft rejection is discussed in this article. The understanding of the different components involved in graft rejection is essential as some of them are used in the clinic as biomarkers to detect and quantify the level of rejection. PMID:24186491

  8. Using Compton scattering for random coincidence rejection

    NASA Astrophysics Data System (ADS)

    Kolstein, M.; Chmeissani, M.

    2016-12-01

    The Voxel Imaging PET (VIP) project presents a new approach for the design of nuclear medicine imaging devices by using highly segmented pixel CdTe sensors. CdTe detectors can achieve an energy resolution of ≈ 1% FWHM at 511 keV and can be easily segmented into submillimeter sized voxels for optimal spatial resolution. These features help in rejecting a large part of the scattered events from the PET coincidence sample in order to obtain high quality images. Another contribution to the background are random events, i.e., hits caused by two independent gammas without a common origin. Given that 60% of 511 keV photons undergo Compton scattering in CdTe (i.e. 84% of all coincidence events have at least one Compton scattering gamma), we present a simulation study on the possibility to use the Compton scattering information of at least one of the coincident gammas within the detector to reject random coincidences. The idea uses the fact that if a gamma undergoes Compton scattering in the detector, it will cause two hits in the pixel detectors. The first hit corresponds to the Compton scattering process. The second hit shall correspond to the photoelectric absorption of the remaining energy of the gamma. With the energy deposition of the first hit, one can calculate the Compton scattering angle. By measuring the hit location of the coincident gamma, we can construct the geometric angle, under the assumption that both gammas come from the same origin. Using the difference between the Compton scattering angle and the geometric angle, random events can be rejected.

  9. Optimized data masks for focussed solar tomography: background and artificial diagnostic experiments

    NASA Astrophysics Data System (ADS)

    Hughes, S. J.; Pijpers, F. P.; Thompson, M. J.

    2007-06-01

    Context: The use of solar tomography for detecting subsurface features in the Sun is now well established. It customarily proceeds from an analysis of data on the solar surface given weightings in a predetermined geometric (e.g. centre-annulus) configuration. Aims: We seek to improve these weightings by developing a scheme for choosing optimal combinations of data that maximise the contribution from signal at a desired horizontal and depth location. Methods: We employ a subtractive optimally localized averaging (SOLA) scheme to pick weights for particular data points and analyse the quality of the results. Results: We show in this work that particularly by using wave kernels instead of rays for modelling purposes, one can do well at localizing a measurement through our techniques while achieving desirable error-magnification properties.

  10. Development of optimized detector/spectrophotometer technology for low background space astronomy missions

    NASA Technical Reports Server (NTRS)

    Jones, B.

    1985-01-01

    This program was directed towards a better understanding of some of the important factors in the performance of infrared detector arrays at low background conditions appropriate for space astronomy. The arrays were manufactured by Aerojet Electrosystems Corporation, Azusa. Two arrays, both bismuth doped silicon, were investigated: an AMCID 32x32 Engineering mosiac Si:Bi accumulation mode charge injection device detector array and a metal oxide semiconductor/field effect transistor (MOS-FET) switched array of 16x32 pixels.

  11. Optimizing the Kinematics, Backgrounds and Technology for a Next Generation Qpweak Measurement

    NASA Astrophysics Data System (ADS)

    Carlini, Roger; Qweak Collaboration

    2014-09-01

    The recent Qweakp measurement at JLab was optimized to deliver the highest possible precision within the constraints of the available beam time, energies, polarized beam current, target technology, beam quality and kinematic requirements for the suppression of theoretical uncertainties. Applying what we have learned towards maximizing the figure-of-merit of a possible more precise next generation measurement suggests focusing on decreasing the beam energy (and Q2), but only enough to sufficiently suppress theoretical correction uncertainties, while still keeping the scattering asymmetry as high as possible. This insures that the running time remains reasonable and demands on helicity correlated beam properties stay within practical limits. Of equal importance is to remain sufficiently high in electron beam energy (400 MeV to 600 MeV) that proven technologies can be employed for the most critical ancillary measurements - such as precision laser backscattering beam polarimetry. The above conditions seem at least technically feasible if given the availability of a lower energy electron beam, sufficient running time and polarized beam current while still allowing the use of much of the previous generation Qweak instrumentation and methodology.

  12. Detection of Foreign Matter in Transfusion Solution Based on Gaussian Background Modeling and an Optimized BP Neural Network

    PubMed Central

    Zhou, Fuqiang; Su, Zhen; Chai, Xinghua; Chen, Lipeng

    2014-01-01

    This paper proposes a new method to detect and identify foreign matter mixed in a plastic bottle filled with transfusion solution. A spin-stop mechanism and mixed illumination style are applied to obtain high contrast images between moving foreign matter and a static transfusion background. The Gaussian mixture model is used to model the complex background of the transfusion image and to extract moving objects. A set of features of moving objects are extracted and selected by the ReliefF algorithm, and optimal feature vectors are fed into the back propagation (BP) neural network to distinguish between foreign matter and bubbles. The mind evolutionary algorithm (MEA) is applied to optimize the connection weights and thresholds of the BP neural network to obtain a higher classification accuracy and faster convergence rate. Experimental results show that the proposed method can effectively detect visible foreign matter in 250-mL transfusion bottles. The misdetection rate and false alarm rate are low, and the detection accuracy and detection speed are satisfactory. PMID:25347581

  13. Optimization of advanced Wiener estimation methods for Raman reconstruction from narrow-band measurements in the presence of fluorescence background.

    PubMed

    Chen, Shuo; Ong, Yi Hong; Lin, Xiaoqian; Liu, Quan

    2015-07-01

    Raman spectroscopy has shown great potential in biomedical applications. However, intrinsically weak Raman signals cause slow data acquisition especially in Raman imaging. This problem can be overcome by narrow-band Raman imaging followed by spectral reconstruction. Our previous study has shown that Raman spectra free of fluorescence background can be reconstructed from narrow-band Raman measurements using traditional Wiener estimation. However, fluorescence-free Raman spectra are only available from those sophisticated Raman setups capable of fluorescence suppression. The reconstruction of Raman spectra with fluorescence background from narrow-band measurements is much more challenging due to the significant variation in fluorescence background. In this study, two advanced Wiener estimation methods, i.e. modified Wiener estimation and sequential weighted Wiener estimation, were optimized to achieve this goal. Both spontaneous Raman spectra and surface enhanced Raman spectra were evaluated. Compared with traditional Wiener estimation, two advanced methods showed significant improvement in the reconstruction of spontaneous Raman spectra. However, traditional Wiener estimation can work as effectively as the advanced methods for SERS spectra but much faster. The wise selection of these methods would enable accurate Raman reconstruction in a simple Raman setup without the function of fluorescence suppression for fast Raman imaging.

  14. Optimization of advanced Wiener estimation methods for Raman reconstruction from narrow-band measurements in the presence of fluorescence background

    PubMed Central

    Chen, Shuo; Ong, Yi Hong; Lin, Xiaoqian; Liu, Quan

    2015-01-01

    Raman spectroscopy has shown great potential in biomedical applications. However, intrinsically weak Raman signals cause slow data acquisition especially in Raman imaging. This problem can be overcome by narrow-band Raman imaging followed by spectral reconstruction. Our previous study has shown that Raman spectra free of fluorescence background can be reconstructed from narrow-band Raman measurements using traditional Wiener estimation. However, fluorescence-free Raman spectra are only available from those sophisticated Raman setups capable of fluorescence suppression. The reconstruction of Raman spectra with fluorescence background from narrow-band measurements is much more challenging due to the significant variation in fluorescence background. In this study, two advanced Wiener estimation methods, i.e. modified Wiener estimation and sequential weighted Wiener estimation, were optimized to achieve this goal. Both spontaneous Raman spectra and surface enhanced Raman spectra were evaluated. Compared with traditional Wiener estimation, two advanced methods showed significant improvement in the reconstruction of spontaneous Raman spectra. However, traditional Wiener estimation can work as effectively as the advanced methods for SERS spectra but much faster. The wise selection of these methods would enable accurate Raman reconstruction in a simple Raman setup without the function of fluorescence suppression for fast Raman imaging. PMID:26203387

  15. Optimal Combination of Neural Temporal Envelope and Fine Structure Cues to Explain Speech Identification in Background Noise

    PubMed Central

    Moon, Il Joon; Won, Jong Ho; Ives, D. Timothy; Nie, Kaibao; Heinz, Michael G.; Lorenzi, Christian; Rubinstein, Jay T.

    2014-01-01

    The dichotomy between acoustic temporal envelope (ENV) and fine structure (TFS) cues has stimulated numerous studies over the past decade to understand the relative role of acoustic ENV and TFS in human speech perception. Such acoustic temporal speech cues produce distinct neural discharge patterns at the level of the auditory nerve, yet little is known about the central neural mechanisms underlying the dichotomy in speech perception between neural ENV and TFS cues. We explored the question of how the peripheral auditory system encodes neural ENV and TFS cues in steady or fluctuating background noise, and how the central auditory system combines these forms of neural information for speech identification. We sought to address this question by (1) measuring sentence identification in background noise for human subjects as a function of the degree of available acoustic TFS information and (2) examining the optimal combination of neural ENV and TFS cues to explain human speech perception performance using computational models of the peripheral auditory system and central neural observers. Speech-identification performance by human subjects decreased as the acoustic TFS information was degraded in the speech signals. The model predictions best matched human performance when a greater emphasis was placed on neural ENV coding rather than neural TFS. However, neural TFS cues were necessary to account for the full effect of background-noise modulations on human speech-identification performance. PMID:25186758

  16. "Science" Rejects Postmodernism.

    ERIC Educational Resources Information Center

    St. Pierre, Elizabeth Adams

    2002-01-01

    The National Research Council report, "Scientific Research in Education," claims to present an inclusive view of sciences in responding to federal attempts to legislate educational research. This article asserts that it narrowly defines science as positivism and methodology as quantitative, rejecting postmodernism and omitting other theories. Uses…

  17. The Application of Auto-Disturbance Rejection Control Optimized by Least Squares Support Vector Machines Method and Time-Frequency Representation in Voltage Source Converter-High Voltage Direct Current System

    PubMed Central

    Gao, Zhong-Ke

    2015-01-01

    In order to improve the performance of voltage source converter-high voltage direct current (VSC-HVDC) system, we propose an improved auto-disturbance rejection control (ADRC) method based on least squares support vector machines (LSSVM) in the rectifier side. Firstly, we deduce the high frequency transient mathematical model of VSC-HVDC system. Then we investigate the ADRC and LSSVM principles. We ignore the tracking differentiator in the ADRC controller aiming to improve the system dynamic response speed. On this basis, we derive the mathematical model of ADRC controller optimized by LSSVM for direct current voltage loop. Finally we carry out simulations to verify the feasibility and effectiveness of our proposed control method. In addition, we employ the time-frequency representation methods, i.e., Wigner-Ville distribution (WVD) and adaptive optimal kernel (AOK) time-frequency representation, to demonstrate our proposed method performs better than the traditional method from the perspective of energy distribution in time and frequency plane. PMID:26098556

  18. The Application of Auto-Disturbance Rejection Control Optimized by Least Squares Support Vector Machines Method and Time-Frequency Representation in Voltage Source Converter-High Voltage Direct Current System.

    PubMed

    Liu, Ying-Pei; Liang, Hai-Ping; Gao, Zhong-Ke

    2015-01-01

    In order to improve the performance of voltage source converter-high voltage direct current (VSC-HVDC) system, we propose an improved auto-disturbance rejection control (ADRC) method based on least squares support vector machines (LSSVM) in the rectifier side. Firstly, we deduce the high frequency transient mathematical model of VSC-HVDC system. Then we investigate the ADRC and LSSVM principles. We ignore the tracking differentiator in the ADRC controller aiming to improve the system dynamic response speed. On this basis, we derive the mathematical model of ADRC controller optimized by LSSVM for direct current voltage loop. Finally we carry out simulations to verify the feasibility and effectiveness of our proposed control method. In addition, we employ the time-frequency representation methods, i.e., Wigner-Ville distribution (WVD) and adaptive optimal kernel (AOK) time-frequency representation, to demonstrate our proposed method performs better than the traditional method from the perspective of energy distribution in time and frequency plane.

  19. Image rejects in general direct digital radiography

    PubMed Central

    Rosanowsky, Tine Blomberg; Jensen, Camilla; Wah, Kenneth Hong Ching

    2015-01-01

    Background The number of rejected images is an indicator of image quality and unnecessary imaging at a radiology department. Image reject analysis was frequent in the film era, but comparably few and small studies have been published after converting to digital radiography. One reason may be a belief that rejects have been eliminated with digitalization. Purpose To measure the extension of deleted images in direct digital radiography (DR), in order to assess the rates of rejects and unnecessary imaging and to analyze reasons for deletions, in order to improve the radiological services. Material and Methods All exposed images at two direct digital laboratories at a hospital in Norway were reviewed in January 2014. Type of examination, number of exposed images, and number of deleted images were registered. Each deleted image was analyzed separately and the reason for deleting the image was recorded. Results Out of 5417 exposed images, 596 were deleted, giving a deletion rate of 11%. A total of 51.3% were deleted due to positioning errors and 31.0% due to error in centering. The examinations with the highest percentage of deleted images were the knee, hip, and ankle, 20.6%, 18.5%, and 13.8% respectively. Conclusion The reject rate is at least as high as the deletion rate and is comparable with previous film-based imaging systems. The reasons for rejection are quite different in digital systems. This falsifies the hypothesis that digitalization would eliminates rejects. A deleted image does not contribute to diagnostics, and therefore is an unnecessary image. Hence, the high rates of deleted images have implications for management, training, education, as well as for quality. PMID:26500784

  20. Separation of sodium chloride from the evaporated residue of the reverse osmosis reject generated in the leather industry--optimization by response surface methodology.

    PubMed

    Boopathy, R; Sekaran, G

    2014-08-01

    Reverse osmosis (RO) concentrate is being evaporated by solar/thermal evaporators to meet zero liquid discharge standards. The resulted evaporated residue (ER) is contaminated with both organic and inorganic mixture of salts. The generation of ER is exceedingly huge in the leather industry, which is being collected and stored under the shelter to avoid groundwater contamination by the leachate. In the present investigation, a novel process for the separation of sodium chloride from ER was developed, to reduce the environmental impact on RO concentrate discharge. The sodium chloride was selectively separated by the reactive precipitation method using hydrogen chloride gas. The selected process variables were optimized for maximum yield ofNaCl from the ER (optimum conditions were pH, 8.0; temperature, 35 degrees C; concentration of ER, 600 g/L and HCl purging time, 3 min). The recovered NaCl purity was verified using a cyclic voltagramm.

  1. Soothing the Sting of Rejection.

    ERIC Educational Resources Information Center

    Campbell, Joan Daniels

    1990-01-01

    Preventing rejection of a student by his/her peers and helping the child to cope with such rejection are ever-present challenges for teachers. Suggestions are given by teachers who have successfully dealt with students who were rejected by classmates. (IAH)

  2. Soothing the Sting of Rejection.

    ERIC Educational Resources Information Center

    Campbell, Joan Daniels

    1990-01-01

    Preventing rejection of a student by his/her peers and helping the child to cope with such rejection are ever-present challenges for teachers. Suggestions are given by teachers who have successfully dealt with students who were rejected by classmates. (IAH)

  3. Heat rejection system

    DOEpatents

    Smith, Gregory C.; Tokarz, Richard D.; Parry, Jr., Harvey L.; Braun, Daniel J.

    1980-01-01

    A cooling system for rejecting waste heat consists of a cooling tower incorporating a plurality of coolant tubes provided with cooling fins and each having a plurality of cooling channels therein, means for directing a heat exchange fluid from the power plant through less than the total number of cooling channels to cool the heat exchange fluid under normal ambient temperature conditions, means for directing water through the remaining cooling channels whenever the ambient temperature rises above the temperature at which dry cooling of the heat exchange fluid is sufficient and means for cooling the water.

  4. MRI Investigation of Macrophages in Acute Cardiac Allograft Rejection after Heart Transplantation

    PubMed Central

    Wu, Yijen L.; Ye, Qing; Eytan, Danielle F.; Liu, Li; Rosario, Bedda L.; Hitchens, T. Kevin; Yeh, Fang-Cheng; van Rooijen, Nico; Ho, Chien

    2013-01-01

    Background Current immunosuppressive therapy after heart transplantation either generally suppresses the recipient’s entire immune system or is mainly targeting T-lymphocytes. Monocytes/macrophages are recognized as a hallmark of acute allograft rejection, but the roles that they play are not well characterized in vivo, because the tools for accessing in-situ macrophage infiltration are lacking. In this study, we utilize MRI to investigate the role of macrophages in acute heart allograft rejection by cellular and functional MRI with selectively depleted systemic macrophages without affecting other leukocyte population and to explore the possibility that macrophages could be an alternative therapeutic target. Methods and Results A rodent heterotopic working heart-lung transplantation model was employed for studying acute allograft rejection. Systemic macrophages were selectively depleted by treating recipient animals with clodronate-liposomes. Macrophage infiltration in the graft hearts was monitored by cellular MRI with in-vivo ultra-small iron-oxide particles (USPIO) labeling. Graft heart function was evaluated by tagging MRI, followed by strain analysis. Clodronate-liposome-treatment depletes circulating monocytes/macrophages in transplant recipients, and both cellular MRI and pathological examinations indicate a significant reduction in macrophage accumulation in the rejecting allograft hearts. In clodronate-liposome-treated group, allograft hearts exhibit preserved tissue integrity, partially reverse functional deterioration, and prolong graft survival, compared to untreated controls. Conclusions Cardiac cellular and functional MRI is a powerful tool to explore the roles of targeted immune cells in vivo. Our results indicate that macrophages are essential in acute cardiac allograft rejection, and selective depletion of macrophages with clodronate-liposomes protects hearts against allograft rejection, suggesting a potential therapeutic avenue. Our findings

  5. Language Skills, Peer Rejection, and the Development of Externalizing Behavior from Kindergarten to Fourth Grade

    ERIC Educational Resources Information Center

    Menting, Barbara; Van Lier, Pol A. C.; Koot, Hans M.

    2011-01-01

    Background: Children with poorer language skills are more likely to show externalizing behavior problems, as well as to become rejected by their peers. Peer rejection has also been found to affect the development of externalizing behavior. This study explored the role of peer rejection in the link between language skills and the development of…

  6. Optical communication noise rejection using corelated photons

    NASA Technical Reports Server (NTRS)

    Jackson, D.; Hockney, G. M.; Dowling, J. P.

    2002-01-01

    This paper describes a completely new way to perform noise rejection using photons correlated through quantum entanglement to improve an optical communications link in the presence of uncorrelated noise. In particular, a detailed analysis is made of the case where a classical link would be saturated by an intense background, such as when a satellite is in front of the sun, and identifies where the quantum correlating system has superior performance.

  7. Optical communication noise rejection using corelated photons

    NASA Technical Reports Server (NTRS)

    Jackson, D.; Hockney, G. M.; Dowling, J. P.

    2002-01-01

    This paper describes a completely new way to perform noise rejection using photons correlated through quantum entanglement to improve an optical communications link in the presence of uncorrelated noise. In particular, a detailed analysis is made of the case where a classical link would be saturated by an intense background, such as when a satellite is in front of the sun, and identifies where the quantum correlating system has superior performance.

  8. Escaping from Rejection

    PubMed Central

    Lynch, Raymond J.; Platt, Jeffrey L.

    2009-01-01

    Summary Those engaged in clinical transplantation and transplantation immunology have always taken as a central objective the elucidation of means to prevent graft rejection by the recipient immune system. Conceptually, such mechanisms stem from the concept of Paul Ehrlich that all organisms can selectively avoid autotoxicity; i.e. they exhibit horror autotoxicus. Some mechanisms of horror autotoxicus now understood. T lymphocytes and B lymphocytes recognize foreign antigens but not some auto-antigens. Clonal deletion generates lacunae in what is otherwise a virtually limitless potential to recognize antigens. We call this mechanism structural tolerance. Where imperfections in structural tolerance allow self-recognition, the full activation of lymphocytes and generation of effector activity depends on delivery of accessory signals generated by infection and/or injury. The absence of accessory signals prevents or even suppresses immunological responses. We call this dichotomy of responsiveness conditional tolerance. When, despite structural and conditional tolerance, effector activity perturbs autologous cells, metabolism changes in ways that protect against injury. We use the term accommodation to refer to this acquired protection against injury. Structural and conditional tolerance and accommodation overlap in such a way that potentially toxic products can be generated to control microorganisms and neutralize toxins without overly damaging adjacent cells. The central challenge in transplantation, then, should be the orchestration of structural and conditional tolerance and accommodation in such a way that toxic products can still be generated for defense while preserving graft function and survival. Since the earliest days of transplantation, immunobiologists have sought means by which to prevent recognition and rejection of foreign tissue. The goal of these strategies is the retention of recipient immune function while selectively avoiding graft injury. While

  9. Jet Transport Rejected Takeoffs.

    DTIC Science & Technology

    1977-02-01

    r _ _ _ _ _ _ N AD—A05 6 032 FEDERAL AVIATIO N ADMINISTRATION WASHINGTON 0 C FLIGHT—ETC FIG 1/2 ~,JET TRANSPORT REJECTED TAKEOFFS • (U)FED 77 0 S...AF~~16O-77-2 FOR FURTHER IRAN JET TRANSPORT R&JECTED TAKEDFFS DAVID W. OSTROWSKILI~~ H c ,~ ~~~~ C ...) ~~~~ O~ —1 w DDU FEB~JARY 1977U... FINAL...Pag. .po ,t No. 2 C.o.,,nm.rr, A c c . s s on No . 3. R.c ,pr. ns s Cat alog No. AFS-16~~-77-2_ j

  10. Accepters and Rejecters of Counseling.

    ERIC Educational Resources Information Center

    Rose, Harriett A.; Elton, Charles F.

    Personality differences between students who accept or reject proffered counseling assistance were investigated by comparing personality traits of 116 male students at the University of Kentucky who accepted or rejected letters of invitation to group counseling. Factor analysis of Omnibus Personality Inventory (OPI) scores to two groups of 60 and…

  11. Emotional responses to interpersonal rejection

    PubMed Central

    Leary, Mark R.

    2015-01-01

    A great deal of human emotion arises in response to real, anticipated, remembered, or imagined rejection by other people. Because acceptance by other people improved evolutionary fitness, human beings developed biopsychological mechanisms to apprise them of threats to acceptance and belonging, along with emotional systems to deal with threats to acceptance. This article examines seven emotions that often arise when people perceive that their relational value to other people is low or in potential jeopardy, including hurt feelings, jealousy, loneliness, shame, guilt, social anxiety, and embarrassment. Other emotions, such as sadness and anger, may occur during rejection episodes, but are reactions to features of the situation other than low relational value. The article discusses the evolutionary functions of rejection-related emotions, neuroscience evidence regarding the brain regions that mediate reactions to rejection, and behavioral research from social, developmental, and clinical psychology regarding psychological and behavioral concomitants of interpersonal rejection. PMID:26869844

  12. Emotional responses to interpersonal rejection.

    PubMed

    Leary, Mark R

    2015-12-01

    A great deal of human emotion arises in response to real, anticipated, remembered, or imagined rejection by other people. Because acceptance by other people improved evolutionary fitness, human beings developed biopsychological mechanisms to apprise them of threats to acceptance and belonging, along with emotional systems to deal with threats to acceptance. This article examines seven emotions that often arise when people perceive that their relational value to other people is low or in potential jeopardy, including hurt feelings, jealousy, loneliness, shame, guilt, social anxiety, and embarrassment. Other emotions, such as sadness and anger, may occur during rejection episodes, but are reactions to features of the situation other than low relational value. The article discusses the evolutionary functions of rejection-related emotions, neuroscience evidence regarding the brain regions that mediate reactions to rejection, and behavioral research from social, developmental, and clinical psychology regarding psychological and behavioral concomitants of interpersonal rejection.

  13. Preventing T cell rejection of pig xenografts.

    PubMed

    Higginbotham, Laura; Ford, Mandy L; Newell, Kenneth A; Adams, Andrew B

    2015-11-01

    Xenotransplantation is a potential solution to the limited supply of donor organs. While early barriers to xenograft acceptance, such as hyperacute rejection, are now largely avoided through genetic engineering, the next frontier in successful xenograft survival will require prevention of T cell-mediated rejection. Most successful immunosuppressive regimens in xenotransplantation utilize T cell depletion with antibody therapy. Additionally, the use of T cell costimulatory blockade - specifically blockade of the CD40-CD154 pathway - shows promise with several reports of long-term xenograft survival. Additional therapies, such as transgenic expression of T cell coinhibitory molecules or transfer of immunomodulatory cells to promote tolerance, may be necessary to achieve reliable long-term xenograft acceptance. Further studies in pre-clinical models are essential in order to optimize these regimens prior to trials in patients. Copyright © 2015. Published by Elsevier Ltd.

  14. Background reduction in cryogenic detectors

    SciTech Connect

    Bauer, Daniel A.; /Fermilab

    2005-04-01

    This paper discusses the background reduction and rejection strategy of the Cryogenic Dark Matter Search (CDMS) experiment. Recent measurements of background levels from CDMS II at Soudan are presented, along with estimates for future improvements in sensitivity expected for a proposed SuperCDMS experiment at SNOLAB.

  15. Private Information and Insurance Rejections

    PubMed Central

    Hendren, Nathaniel

    2013-01-01

    Across a wide set of non-group insurance markets, applicants are rejected based on observable, often high-risk, characteristics. This paper argues that private information, held by the potential applicant pool, explains rejections. I formulate this argument by developing and testing a model in which agents may have private information about their risk. I first derive a new no-trade result that theoretically explains how private information could cause rejections. I then develop a new empirical methodology to test whether this no-trade condition can explain rejections. The methodology uses subjective probability elicitations as noisy measures of agents beliefs. I apply this approach to three non-group markets: long-term care, disability, and life insurance. Consistent with the predictions of the theory, in all three settings I find significant amounts of private information held by those who would be rejected; I find generally more private information for those who would be rejected relative to those who can purchase insurance; and I show it is enough private information to explain a complete absence of trade for those who would be rejected. The results suggest private information prevents the existence of large segments of these three major insurance markets. PMID:24187381

  16. Organ transplant tissue rejection: detection and staging by fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    MacAulay, Calum E.; Whitehead, Peter D.; McManus, Bruce; Zeng, Haishan; Wilson-McManus, Janet; MacKinnon, Nick; Morgan, David C.; Dong, Chunming; Gerla, Paul; Kenyon, Jennifer

    1998-07-01

    Patients receiving heart or other organ transplants usually require some level of anti-rejection drug therapy, most commonly cyclosporine. The rejection status of the organ must be monitored to determine the optimal anti-rejection drug therapy. The current method for monitoring post-transplant rejection status of heart transplant patients consists of taking biopsies from the right ventricle. In this work we have developed a system employing optical and signal-processing techniques that will allow a cardiologist to measure spectral changes associated with tissue rejection using an optical catheter probe. The system employs time gated illumination and detection systems to deal with the dynamic signal acquisition problems associated with in vivo measurements of a beating heart. Spectral data processing software evaluates and processes the data to produce a simple numerical score. Results of measurements made on 100 excised transplanted isograft and allograft rat hearts have demonstrated the ability of the system to detect the presence of rejection and to accurately correlate the spectroscopic results with the ISHLT (International Society for Heart and Lung Transplantation) stage of rejection determined by histopathology. In vivo measurements using a pig transplant model are now in process.

  17. Do Scientists Really Reject God?

    ERIC Educational Resources Information Center

    Scott, Eugenie C.

    1998-01-01

    Suggests that the title of the recent Larson and Witham article in the journal Nature, "Leading Scientists Still Reject God", is premature and without reliable data upon which to base it. (Author/CCM)

  18. Do Scientists Really Reject God?

    ERIC Educational Resources Information Center

    Scott, Eugenie C.

    1998-01-01

    Suggests that the title of the recent Larson and Witham article in the journal Nature, "Leading Scientists Still Reject God", is premature and without reliable data upon which to base it. (Author/CCM)

  19. Development and application of a channelized Hotelling observer for DBT optimization on structured background test images with mass simulating targets

    NASA Astrophysics Data System (ADS)

    Petrov, Dimitar; Michielsen, Koen; Cockmartin, Lesley; Zhang, Gouzhi; Young, Kenneth; Marshall, Nicholas; Bosmans, Hilde

    2016-03-01

    Digital breast tomosynthesis (DBT) is a 3D mammography technique that promises better visualization of low contrast lesions than conventional 2D mammography. A wide range of parameters influence the diagnostic information in DBT images and a systematic means of DBT system optimization is needed. The gold standard for image quality assessment is to perform a human observer experiment with experienced readers. Using human observers for optimization is time consuming and not feasible for the large parameter space of DBT. Our goal was to develop a model observer (MO) that can predict human reading performance for standard detection tasks of target objects within a structured phantom and subsequently apply it in a first comparative study. The phantom consists of an acrylic semi-cylindrical container with acrylic spheres of different sizes and the remaining space filled with water. Three types of lesions were included: 3D printed spiculated and non-spiculated mass lesions along with calcification groups. The images of the two mass lesion types were reconstructed with 3 different reconstruction methods (FBP, FBP with SRSAR, MLTRpr) and read by human readers. A Channelized Hotelling model observer was created for the non-spiculated lesion detection task using five Laguerre-Gauss channels, tuned for better performance. For the non-spiculated mass lesions a linear relation between the MO and human observer results was found, with correlation coefficients of 0.956 for standard FBP, 0.998 for FBP with SRSAR and 0.940 for MLTRpr. Both the MO and human observer percentage correct results for the spiculated masses were close to 100%, and showed no difference from each other for every reconstruction algorithm.

  20. Long-term efficacy and safety of Raltegravir combined with optimized background therapy in treatment-experienced patients with drug-resistant HIV infection: week 96 results of the BENCHMRK 1 and 2 Phase III trials.

    PubMed

    Steigbigel, Roy T; Cooper, David A; Teppler, Hedy; Eron, Joseph J; Gatell, Jose M; Kumar, Princy N; Rockstroh, Jurgen K; Schechter, Mauro; Katlama, Christine; Markowitz, Martin; Yeni, Patrick; Loutfy, Mona R; Lazzarin, Adriano; Lennox, Jeffrey L; Clotet, Bonaventura; Zhao, Jing; Wan, Hong; Rhodes, Rand R; Strohmaier, Kim M; Barnard, Richard J; Isaacs, Robin D; Nguyen, Bach-Yen T

    2010-02-15

    BENCHMRK-1 and -2 are ongoing double-blind phase III studies of raltegravir in patients experiencing failure of antiretroviral therapy with triple-class drug-resistant human immunodeficiency virus infection. At week 96 (combined data), raltegravir (400 mg twice daily) plus optimized background therapy was generally well tolerated, with superior and durable antiretroviral and immunological efficacy, compared with optimized background therapy alone.

  1. Membrane rejection of nitrogen compounds

    NASA Technical Reports Server (NTRS)

    Lee, S.; Lueptow, R. M.

    2001-01-01

    Rejection characteristics of nitrogen compounds were examined for reverse osmosis, nanofiltration, and low-pressure reverse osmosis membranes. The rejection of nitrogen compounds is explained by integrating experimental results with calculations using the extended Nernst-Planck model coupled with a steric hindrance model. The molecular weight and chemical structure of nitrogen compounds appear to be less important in determining rejection than electrostatic properties. The rejection is greatest when the Donnan potential exceeds 0.05 V or when the ratio of the solute radius to the pore radius is greater than 0.8. The transport of solute in the pore is dominated by diffusion, although convective transport is significant for organic nitrogen compounds. Electromigration contributes negligibly to the overall solute transport in the membrane. Urea, a small organic compound, has lower rejection than ionic compounds such as ammonium, nitrate, and nitrite, indicating the critical role of electrostatic interaction in rejection. This suggests that better treatment efficiency for organic nitrogen compounds can be obtained after ammonification of urea.

  2. Membrane rejection of nitrogen compounds

    NASA Technical Reports Server (NTRS)

    Lee, S.; Lueptow, R. M.

    2001-01-01

    Rejection characteristics of nitrogen compounds were examined for reverse osmosis, nanofiltration, and low-pressure reverse osmosis membranes. The rejection of nitrogen compounds is explained by integrating experimental results with calculations using the extended Nernst-Planck model coupled with a steric hindrance model. The molecular weight and chemical structure of nitrogen compounds appear to be less important in determining rejection than electrostatic properties. The rejection is greatest when the Donnan potential exceeds 0.05 V or when the ratio of the solute radius to the pore radius is greater than 0.8. The transport of solute in the pore is dominated by diffusion, although convective transport is significant for organic nitrogen compounds. Electromigration contributes negligibly to the overall solute transport in the membrane. Urea, a small organic compound, has lower rejection than ionic compounds such as ammonium, nitrate, and nitrite, indicating the critical role of electrostatic interaction in rejection. This suggests that better treatment efficiency for organic nitrogen compounds can be obtained after ammonification of urea.

  3. The Athena Background

    NASA Astrophysics Data System (ADS)

    Piro, Luigi; Lotti, Simone; Macculi, Claudio; Molendi, Silvano; Eraerds, Tanja; Laurent, Philippe

    2015-09-01

    Estimating, reducing and controlling the residual particle background is fundamental for achieving the objectives of several science topics of Athena, in particular those connected with background dominated observations of faint and/or diffuse sources. This requires assessing the particle environment in L2, propagating the various particle components throughout the mirror, spacecraft, and instruments via proper modelling and simulations of various physical processes, implementing design and h/w measures at instrument and mission level to reduce the un-rejected background and identifying proper calibration methods to control the background variations. Likewise, an adequate knowledge of the XRB, made of components that may vary spatially or temporally, is required as well. Here we will review the present status of the background knowledge, and summarize the activities on-going within Athena at various levels.

  4. Limits, discovery and cut optimization for a Poisson process with uncertainty in background and signal efficiency: TRolke 2.0

    NASA Astrophysics Data System (ADS)

    Lundberg, J.; Conrad, J.; Rolke, W.; Lopez, A.

    2010-03-01

    A C++ class was written for the calculation of frequentist confidence intervals using the profile likelihood method. Seven combinations of Binomial, Gaussian, Poissonian and Binomial uncertainties are implemented. The package provides routines for the calculation of upper and lower limits, sensitivity and related properties. It also supports hypothesis tests which take uncertainties into account. It can be used in compiled C++ code, in Python or interactively via the ROOT analysis framework. Program summaryProgram title: TRolke version 2.0 Catalogue identifier: AEFT_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEFT_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: MIT license No. of lines in distributed program, including test data, etc.: 3431 No. of bytes in distributed program, including test data, etc.: 21 789 Distribution format: tar.gz Programming language: ISO C++. Computer: Unix, GNU/Linux, Mac. Operating system: Linux 2.6 (Scientific Linux 4 and 5, Ubuntu 8.10), Darwin 9.0 (Mac-OS X 10.5.8). RAM:˜20 MB Classification: 14.13. External routines: ROOT ( http://root.cern.ch/drupal/) Nature of problem: The problem is to calculate a frequentist confidence interval on the parameter of a Poisson process with statistical or systematic uncertainties in signal efficiency or background. Solution method: Profile likelihood method, Analytical Running time:<10 seconds per extracted limit.

  5. Hypervigilance to Rejecting Stimuli in Rejection Sensitive Individuals: Behavioral and Neurocognitive Evidence.

    PubMed

    Ehrlich, Katherine B; Gerson, Sarah A; Vanderwert, Ross E; Cannon, Erin N; Fox, Nathan A

    2015-10-01

    Individuals who are high in rejection sensitivity are vigilant toward social cues that signal rejection, and they exhibit attention biases towards information that confirms expectations of rejection. Little is known, however, about the neural correlates of rejection sensitivity. The present study examined whether rejection sensitivity is associated with individuals' neural responses to rejection-relevant information. Female participants, classified as high or average in rejection sensitivity, completed a modified dot-probe task in which a neutral face was paired with either another neutral face or a gaze-averted ("rejecting") face while EEG was collected and ERP components were computed. Behavioral results indicated that average rejection sensitive participants showed an attention bias away from rejecting faces, while high rejection sensitive participants were equally vigilant to neutral and rejecting faces. High rejection sensitivity was associated with ERP components signaling elevated attention and arousal to faces. These findings suggest that rejection sensitivity shapes behavioral and neurocognitive responses to faces.

  6. Linear quadratic output tracking and disturbance rejection

    NASA Astrophysics Data System (ADS)

    Karimi-Ghartemani, Masoud; Khajehoddin, S. Ali; Jain, Praveen; Bakhshai, Alireza

    2011-08-01

    This article introduces the problem of linear quadratic tracking (LQT) where the objective is to design a closed-loop control scheme such that the output signal of the system optimally tracks a given reference signal and rejects a given disturbance. Different performance indices that have been used to address the tracking problem are discussed and an appropriate new form is introduced. It is shown that a solution to the proposed optimality index exists under very mild conditions of stabilisability and detectability of the plant state-space equations. The solution is formulated based on converting the LQT problem to a standard linear quadratic regulation problem. The method is applied to two examples, a first-order plant and a third-order plant, and their simulation results are presented and discussed.

  7. Hypervigilance to Rejecting Stimuli in Rejection Sensitive Individuals: Behavioral and Neurocognitive Evidence

    PubMed Central

    Ehrlich, Katherine B.; Gerson, Sarah A.; Vanderwert, Ross E.; Cannon, Erin N.; Fox, Nathan A.

    2015-01-01

    Individuals who are high in rejection sensitivity are vigilant toward social cues that signal rejection, and they exhibit attention biases towards information that confirms expectations of rejection. Little is known, however, about the neural correlates of rejection sensitivity. The present study examined whether rejection sensitivity is associated with individuals’ neural responses to rejection-relevant information. Female participants, classified as high or average in rejection sensitivity, completed a modified dot-probe task in which a neutral face was paired with either another neutral face or a gaze-averted (“rejecting”) face while EEG was collected and ERP components were computed. Behavioral results indicated that average rejection sensitive participants showed an attention bias away from rejecting faces, while high rejection sensitive participants were equally vigilant to neutral and rejecting faces. High rejection sensitivity was associated with ERP components signaling elevated attention and arousal to faces. These findings suggest that rejection sensitivity shapes behavioral and neurocognitive responses to faces. PMID:26213434

  8. Augmented orbiter heat rejection study

    NASA Technical Reports Server (NTRS)

    Hixon, C. W.

    1981-01-01

    Spacecraft radiator concepts are presented that relieve attitude restrictions required by the shuttle orbiter space radiator for baseline and extended capability STS missions. Cost effective heat rejection kits are considered which add additional capability in the form of attached spacelab radiators or a deployable radiator module.

  9. Vascular rejection in heart transplant recipients.

    PubMed

    Miller, L W; Wesp, A; Jennison, S H; Graham, M A; Martin, T W; McBride, L R; Pennington, D G; Peigh, P

    1993-01-01

    Antibody medicated (vascular) rejection has recently been described in heart transplantation. We report our experience with vascular rejection in a series of 62 patients who did not receive perioperative lymphocyte antibody therapy. Sixty-five rejections were reported, of which 58 (89%) were pure cellular; five (8%) had both cellular and vascular components, and two (3%) had only vascular rejection. Vascular rejection was very common in patients in whom hemodynamic compromise developed, and hemodynamic compromise was significantly more common in vascular than cellular rejection. Treatment for vascular rejection included plasmapheresis, intravenous methylprednisolone, and cyclophosphamide. Only one death occurred in this series, and that occurred in a patient with vascular rejection where the diagnosis and initiation of therapy were delayed. The role of vascular rejection in patients with hemodynamic compromise is discussed.

  10. Analysis of the XRS background

    NASA Technical Reports Server (NTRS)

    Kilbourne, Caroline A.; Boyce, K. R.; Brown, G. V.; Cottam, J.; Fujimoto, R.; Furusho, T.; Ishisaki, Y.; Kelley, R. L.; McCammon, D.; Mitsuda, K.

    2005-01-01

    Background counts on the XRS Calorimeter spectrometer of Astro-E2 have several sources, including primary cosmic rays and secondary particles interacting with the pixels and with the silicon structure of the array. After rejecting events coincident between pixels or between a pixel and the anti-coincidence detector behind the calorimeter array, the residual background on the ground in the 0.1 - 10 keV band is 1e-3 counts/s (8e-3 counts/s/sq cm). We will present the details of the ground background events and the rejection criteria required lo remove them while minimizing deadtime. We will also present preliminary analysis of the in-orbit background.

  11. Active rejection of persistent disturbances in flexible space structures

    NASA Technical Reports Server (NTRS)

    Hwang, Cheng-Neng; Jayasuriya, Suhada; Parlos, Alexander G.; Sunkel, John W.

    1990-01-01

    A dynamic compensator for active rejection of persistent disturbances in flexible space structures is designed on the principle of the H(infinity)-optimization of the sensitivity transfer function matrix. A general state space solution is formulated to the multiinput multioutput H(infinity)-optimal control problem, allowing the use of the H(infinity)-optimal synthesis algorithm for the state-space models of space structures that result from model order reduction. Disturbances encountered in flexible space structures, such as shuttle docking, are investigated using the high-mode and the reduced-order models of a cantilevered two-bay truss, demonstrating the applicability of the H(infinity)-optimal approach.

  12. Enhancing Signal Output and Avoiding BOD/Toxicity Combined Shock Interference by Operating a Microbial Fuel Cell Sensor with an Optimized Background Concentration of Organic Matter

    PubMed Central

    Jiang, Yong; Liang, Peng; Liu, Panpan; Bian, Yanhong; Miao, Bo; Sun, Xueliang; Zhang, Helan; Huang, Xia

    2016-01-01

    In the monitoring of pollutants in an aquatic environment, it is important to preserve water quality safety. Among the available analysis methods, the microbial fuel cell (MFC) sensor has recently been used as a sustainable and on-line electrochemical microbial biosensor for biochemical oxygen demand (BOD) and toxicity, respectively. However, the effect of the background organic matter concentration on toxicity monitoring when using an MFC sensor is not clear and there is no effective strategy available to avoid the signal interference by the combined shock of BOD and toxicity. Thus, the signal interference by the combined shock of BOD and toxicity was systematically studied in this experiment. The background organic matter concentration was optimized in this study and it should be fixed at a high level of oversaturation for maximizing the signal output when the current change (ΔI) is selected to correlate with the concentration of a toxic agent. When the inhibition ratio (IR) is selected, on the other hand, it should be fixed as low as possible near the detection limit for maximizing the signal output. At least two MFC sensors operated with high and low organic matter concentrations and a response chart generated from pre-experiment data were both required to make qualitative distinctions of the four types of combined shock caused by a sudden change in BOD and toxicity. PMID:27563887

  13. Enhancing Signal Output and Avoiding BOD/Toxicity Combined Shock Interference by Operating a Microbial Fuel Cell Sensor with an Optimized Background Concentration of Organic Matter.

    PubMed

    Jiang, Yong; Liang, Peng; Liu, Panpan; Bian, Yanhong; Miao, Bo; Sun, Xueliang; Zhang, Helan; Huang, Xia

    2016-08-24

    In the monitoring of pollutants in an aquatic environment, it is important to preserve water quality safety. Among the available analysis methods, the microbial fuel cell (MFC) sensor has recently been used as a sustainable and on-line electrochemical microbial biosensor for biochemical oxygen demand (BOD) and toxicity, respectively. However, the effect of the background organic matter concentration on toxicity monitoring when using an MFC sensor is not clear and there is no effective strategy available to avoid the signal interference by the combined shock of BOD and toxicity. Thus, the signal interference by the combined shock of BOD and toxicity was systematically studied in this experiment. The background organic matter concentration was optimized in this study and it should be fixed at a high level of oversaturation for maximizing the signal output when the current change (ΔI) is selected to correlate with the concentration of a toxic agent. When the inhibition ratio (IR) is selected, on the other hand, it should be fixed as low as possible near the detection limit for maximizing the signal output. At least two MFC sensors operated with high and low organic matter concentrations and a response chart generated from pre-experiment data were both required to make qualitative distinctions of the four types of combined shock caused by a sudden change in BOD and toxicity.

  14. How to COAAD Images. II. A Coaddition Image that is Optimal for Any Purpose in the Background-dominated Noise Limit

    NASA Astrophysics Data System (ADS)

    Zackay, Barak; Ofek, Eran O.

    2017-02-01

    Image coaddition is one of the most basic operations that astronomers perform. In Paper I, we presented the optimal ways to coadd images in order to detect faint sources and to perform flux measurements under the assumption that the noise is approximately Gaussian. Here, we build on these results and derive from first principles a coaddition technique that is optimal for any hypothesis testing and measurement (e.g., source detection, flux or shape measurements, and star/galaxy separation), in the background-noise-dominated case. This method has several important properties. The pixels of the resulting coadded image are uncorrelated. This image preserves all the information (from the original individual images) on all spatial frequencies. Any hypothesis testing or measurement that can be done on all the individual images simultaneously, can be done on the coadded image without any loss of information. The PSF of this image is typically as narrow, or narrower than the PSF of the best image in the ensemble. Moreover, this image is practically indistinguishable from a regular single image, meaning that any code that measures any property on a regular astronomical image can be applied to it unchanged. In particular, the optimal source detection statistic derived in Paper I is reproduced by matched filtering this image with its own PSF. This coaddition process, which we call proper coaddition, can be understood as the maximum signal-to-noise ratio measurement of the Fourier transform of the image, weighted in such a way that the noise in the entire Fourier domain is of equal variance. This method has important implications for multi-epoch seeing-limited deep surveys, weak lensing galaxy shape measurements, and diffraction-limited imaging via speckle observations. The last topic will be covered in depth in future papers. We provide an implementation of this algorithm in MATLAB.

  15. Alemtuzumab Induction and Delayed Acute Rejection in Steroid-Free Simultaneous Pancreas-Kidney Transplant Recipients

    PubMed Central

    Bank, Jonna R.; Heidt, Sebastiaan; Moes, Dirk Jan A. R.; Roelen, Dave L.; Mallat, Marko J. K.; van der Boog, Paul J.M.; Vergunst, Manon; Jol-van der Zijde, Cornelia M.; Bredius, Robbert G. M.; Braat, Andries E.; Ringers, Jan; van Tol, Maarten J. D.; Claas, Frans H. J.; Reinders, Marlies E. J.; de Fijter, Johannes W.

    2017-01-01

    Background The optimal immunosuppressive regimen in simultaneous pancreas-kidney transplant (SPKT) recipients that prevents acute rejection episodes (AREs) and allows optimal outcome remains elusive. Methods This cohort study assessed incidence and time to AREs in 73 consecutive SPKT recipients receiving alemtuzumab induction and steroid-free maintenance with tacrolimus and mycophenolate mofetil. A cohort with single high-dose antithymocyte globulin (ATG; n = 85) and triple therapy served as controls. In addition, we provided mechanistic insights in AREs after alemtuzumab depletion, including composition and alloreactivity of lymphocytes (flow cytometry and mixed lymphocyte reaction) plasma alemtuzumab levels (enzyme-linked immunosorbent assay), and maintenance drug exposure. Results Overall number of AREs at 3 years was significantly lower with alemtuzumab versus ATG induction (26.0% vs 43.5%; adjusted hazard ratio, 0.38; P = 0.029). Most AREs (94.6%) with ATG occurred within the first month, whereas 84.2% of AREs with alemtuzumab occurred beyond 3 months. Patients with and without an ARE in the steroid-free alemtuzumab group showed no differences in composition of lymphocytes, or in alemtuzumab levels. Of note, more than two thirds of these AREs were preceded by empiric tacrolimus and/or mycophenolate mofetil dose adjustments due to viral infections, leukopenia, or gastrointestinal symptoms. Conclusions Alemtuzumab induction resulted in a significant lower incidence of AREs. Empiric dose adjustments beyond 3 months in the absence of steroids carry a significant risk for subsequent rejection in SPKT recipients. PMID:28349124

  16. Antibody-Mediated Rejection: A Review

    PubMed Central

    Garces, Jorge Carlos; Giusti, Sixto; Staffeld-Coit, Catherine; Bohorquez, Humberto; Cohen, Ari J.; Loss, George E.

    2017-01-01

    Background: Chronic antibody injury is a serious threat to allograft outcomes and is therefore the center of active research. In the continuum of allograft rejection, the development of antibodies plays a critical role. In recent years, an increased recognition of molecular and histologic changes has provided a better understanding of antibody-mediated rejection (AMR), as well as potential therapeutic interventions. However, several pathways are still unknown, which accounts for the lack of efficacy of some of the currently available agents that are used to treat rejection. Methods: We review the current diagnostic criteria for AMR; AMR paradigms; and desensitization, treatment, and prevention strategies. Results: Chronic antibody-mediated endothelial injury results in transplant glomerulopathy, manifested as glomerular basement membrane duplication, double contouring, or splitting. Clinical manifestations of AMR include proteinuria and a rise in serum creatinine. Current strategies for the treatment of AMR include antibody depletion with plasmapheresis (PLEX), immunoadsorption (IA), immunomodulation with intravenous immunoglobulin (IVIG), and T cell– or B cell–depleting agents. Some treatment benefits have been found in using PLEX and IA, and some small nonrandomized trials have identified some benefits in using rituximab and the proteasome inhibitor-based therapy bortezomib. More recent histologic follow-ups of patients treated with bortezomib have not shown significant benefits in terms of allograft outcomes. Furthermore, no specific treatment approaches have been approved by the US Food and Drug Administration. Other agents used for more difficult rejections include bortezomib and eculizumab (an anti-C5 monoclonal antibody). Conclusion: AMR is a fascinating field with ample opportunities for research and progress in the future. Despite the use of advanced techniques for the detection of human leukocyte antigen (HLA) or non-HLA donor-specific antibodies

  17. Solar Rejection Filter for Large Telescopes

    NASA Technical Reports Server (NTRS)

    Hemmati, Hamid; Lesh, James

    2009-01-01

    To reject solar radiation photons at the front aperture for large telescopes, a mosaic of large transmission mode filters is placed in front of the telescope or at the aperture of the dome. Filtering options for effective rejection of sunlight include a smaller filter down-path near the focus of the telescope, and a large-diameter filter located in the front of the main aperture. Two types of large filters are viable: reflectance mode and transmittance mode. In the case of reflectance mode, a dielectric coating on a suitable substrate (e.g. a low-thermal-expansion glass) is arranged to reflect only a single, narrow wavelength and to efficiently transmit all other wavelengths. These coatings are commonly referred to as notch filter. In this case, the large mirror located in front of the telescope aperture reflects the received (signal and background) light into the telescope. In the case of transmittance mode, a dielectric coating on a suitable substrate (glass, sapphire, clear plastic, membrane, and the like) is arranged to transmit only a single wavelength and to reject all other wavelengths (visible and near IR) of light. The substrate of the large filter will determine its mass. At first glance, a large optical filter with a diameter of up to 10 m, located in front of the main aperture, would require a significant thickness to avoid sagging. However, a segmented filter supported by a structurally rugged grid can support smaller filters. The obscuration introduced by the grid is minimal because the total area can be made insignificant. This configuration can be detrimental to a diffraction- limited telescope due to diffraction effects at the edges of each sub-panel. However, no discernable degradation would result for a 20 diffraction-limit telescope (a photon bucket). Even the small amount of sagging in each subpanel should have minimal effect in the performance of a non-diffraction limited telescope because the part has no appreciable optical power. If the

  18. Fluoride transport due to injection of reject water from RO process into the ground water through downstream bore well.

    PubMed

    Babu, C Anand; Agarwal, Sourabh; Sujish, D; Rajan, K K

    2011-10-01

    Fluoride removal using Reverse Osmosis has appreciable amount of fluorine in the reject stream. Disposal of reject water to surface water further contaminates the water body. It is required to dispose of this reject into the environment with minimal pollution. So a study on disposal of fluoride contaminated reject inside the ground water through bore well is done through theoretical modelling using COMSOL multiphysics software. It has been established that the rise in fluoride concentration in ground water due to injection of fluoride contaminated reject through bore well depends on the injection rate of reject inside the bore well and not on the initial background concentration of fluoride in the ground water. It has been found that for reject injection rate of 30 m3/day the rise in fluoride concentration in ground water with respect to initial background concentration of fluoride is less than 10% at a distance above 600m from the injection source after 100 years.

  19. Collimator optimization in myocardial perfusion SPECT using the ideal observer and realistic background variability for lesion detection and joint detection and localization tasks

    NASA Astrophysics Data System (ADS)

    Ghaly, Michael; Du, Yong; Links, Jonathan M.; Frey, Eric C.

    2016-03-01

    In SPECT imaging, collimators are a major factor limiting image quality and largely determine the noise and resolution of SPECT images. In this paper, we seek the collimator with the optimal tradeoff between image noise and resolution with respect to performance on two tasks related to myocardial perfusion SPECT: perfusion defect detection and joint detection and localization. We used the Ideal Observer (IO) operating on realistic background-known-statistically (BKS) and signal-known-exactly (SKE) data. The areas under the receiver operating characteristic (ROC) and localization ROC (LROC) curves (AUCd, AUCd+l), respectively, were used as the figures of merit for both tasks. We used a previously developed population of 54 phantoms based on the eXtended Cardiac Torso Phantom (XCAT) that included variations in gender, body size, heart size and subcutaneous adipose tissue level. For each phantom, organ uptakes were varied randomly based on distributions observed in patient data. We simulated perfusion defects at six different locations with extents and severities of 10% and 25%, respectively, which represented challenging but clinically relevant defects. The extent and severity are, respectively, the perfusion defect’s fraction of the myocardial volume and reduction of uptake relative to the normal myocardium. Projection data were generated using an analytical projector that modeled attenuation, scatter, and collimator-detector response effects, a 9% energy resolution at 140 keV, and a 4 mm full-width at half maximum (FWHM) intrinsic spatial resolution. We investigated a family of eight parallel-hole collimators that spanned a large range of sensitivity-resolution tradeoffs. For each collimator and defect location, the IO test statistics were computed using a Markov Chain Monte Carlo (MCMC) method for an ensemble of 540 pairs of defect-present and -absent images that included the aforementioned anatomical and uptake variability. Sets of test statistics were

  20. Collimator optimization in myocardial perfusion SPECT using the ideal observer and realistic background variability for lesion detection and joint detection and localization tasks

    PubMed Central

    Ghaly, Michael; Du, Yong; Links, Jonathan M; Frey, Eric C

    2016-01-01

    In SPECT imaging, collimators are a major factor limiting image quality and largely determine the noise and resolution of SPECT images. In this paper, we seek the collimator with the optimal tradeoff between image noise and resolution with respect to performance on two tasks related to myocardial perfusion SPECT: perfusion defect detection and joint detection and localization. We used the Ideal Observer (IO) operating on realistic background-known-statistically (BKS) and signal-known-exactly (SKE) data. The areas under the receiver operating characteristic (ROC) and localization ROC (LROC) curves (AUCd, AUCd+l), respectively, were used as the figures of merit for both tasks. We used a previously developed population of 54 phantoms based on the eXtended Cardiac Torso Phantom (XCAT) that included variations in gender, body size, heart size and subcutaneous adipose tissue level. For each phantom, organ uptakes were varied randomly based on distributions observed in patient data. We simulated perfusion defects at six different locations with extents and severities of 10% and 25%, respectively, which represented challenging but clinically relevant defects. The extent and severity are, respectively, the perfusion defect's fraction of the myocardial volume and reduction of uptake relative to the normal myocardium. Projection data were generated using an analytical projector that modeled attenuation, scatter, and collimator-detector response effects, a 9% energy resolution at 140 keV, and a 4 mm full-width at half maximum (FWHM) intrinsic spatial resolution. We investigated a family of eight parallel-hole collimators that spanned a large range of sensitivity-resolution tradeoffs. For each collimator and defect location, the IO test statistics were computed using a Markov Chain Monte Carlo (MCMC) method for an ensemble of 540 pairs of defect-present and -absent images that included the aforementioned anatomical and uptake variability. Sets of test statistics were computed

  1. REJECTION OF ASCITES TUMOR ALLOGRAFTS

    PubMed Central

    Berke, Gideon; Sullivan, Karen A.; Amos, Bernard

    1972-01-01

    Peritoneal exudate cells (PEC), obtained after the rejection of EL4 leukemia by BALB/c mice, are much more effective in the specific in vitro destruction of 51Cr-labeled EL4 cells than are spleen, thymus, lymph node, or peripheral blood lymphocytes. The presence of a large number of effector cells at the site of graft rejection is reflected in the potent cytolytic activity seen in vitro. Effector cells temporarily lose cytolytic reactivity when treated with trypsin but regain reactivity with time. This recovery occurs in normal as well as in immune serum. The destructive reactivity of PEC is increased when macrophages are removed. The remaining population of nonadherent PEC is composed primarily of small- to medium-sized lymphocytes. Complex tissue culture media are not needed, but there is a definite requirement for serum. The required serum component is heat stable, nondialyzable, and is not consumed during the reaction. The use of an ascites allograft system made these observations possible and permitted the isolation of those host cells intimately associated with rejection. PMID:5025438

  2. GPS antenna multipath rejection performance

    NASA Astrophysics Data System (ADS)

    Dinius, A. M.

    1995-08-01

    A GPS antenna multipath rejection performance evaluation was conducted. Ground reference station antennas and aviation patches were tested for their ability to reject a multipath signal. Different types of ground plane structures were used such as choke rings, ground planes, and mock sections of fuselage. Frequencies transmitted were L1 (1575 MHz), L2 (1227 MHz), and the median GLONASS frequency (1609 MHz). Receive amplitude and phase were measured on each antenna. Subsequently, these data were converted to absolute gain for a right hand and left hand circularly polarized signal as a function of satellite elevation angle. Two types of multipath signals were considered: ground bounce multipath and building or structure bounce multipath. Ground bounce multipath typically occurs at low satellite elevation angles while structure bounce multipath can occur at any satellite elevation angle. Separate analysis methods were used to assess an antenna's ability to reject either type of multipath. This report describes the data collection methods, data reduction and analysis, and the results.

  3. 7 CFR 58.136 - Rejected milk.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Rejected milk. 58.136 Section 58.136 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Milk § 58.136 Rejected milk. A plant shall reject specific milk from a producer if the milk fails...

  4. On fiber rejection loss in flotation deinking

    Treesearch

    J.Y. Zhu; Freya Tan

    2005-04-01

    Reducing fiber rejection loss in flotation deinking is very important to conserve natural resources and reduce the cost of secondary fibers in paper recycling. This study examined two aspects of the problem, fiber consistency in the rejection stream and rate of Froth (or wet stream) rejection. Flotation experiments were conducted using both nylon and wood fibers in...

  5. Peer Group Rejection and Children's Outgroup Prejudice

    ERIC Educational Resources Information Center

    Nesdale, Drew; Durkin, Kevin; Maass, Anne; Kiesner, Jeff; Griffiths, Judith; Daly, Josh; McKenzie, David

    2010-01-01

    Two simulation studies examined the effect of peer group rejection on 7 and 9 year old children's outgroup prejudice. In Study 1, children (n = 88) pretended that they were accepted or rejected by their assigned group, prior to competing with a lower status outgroup. Results indicated that rejected versus accepted children showed increased…

  6. Social Causes and Consequences of Rejection Sensitivity

    ERIC Educational Resources Information Center

    London, Bonita; Downey, Geraldine; Bonica, Cheryl; Paltin, Iris

    2007-01-01

    Predictions from the Rejection Sensitivity (RS) model concerning the social causes and consequences of RS were examined in a longitudinal study of 150 middle school students. Peer nominations of rejection, self-report measures of anxious and angry rejection expectations, and social anxiety, social withdrawal, and loneliness were assessed at two…

  7. Aggressive Rejected Children: Implications for School Psychologists.

    ERIC Educational Resources Information Center

    Waas, Gregory A.

    1987-01-01

    Used sociometric rating procedure to classify third and fifth grade boys (N=64) as peer-rejected. Standardized teacher ratings classified students as aggressive. Significant portion of rejected students were rated as highly aggressive. Aggressive rejected groups were rated as exhibiting lower achievement motivation and higher levels of hostile…

  8. 7 CFR 58.136 - Rejected milk.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Rejected milk. 58.136 Section 58.136 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Milk § 58.136 Rejected milk. A plant shall reject specific milk from a producer if the milk fails to...

  9. 7 CFR 58.136 - Rejected milk.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Rejected milk. 58.136 Section 58.136 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Milk § 58.136 Rejected milk. A plant shall reject specific milk from a producer if the milk fails to...

  10. 7 CFR 58.136 - Rejected milk.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Rejected milk. 58.136 Section 58.136 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Milk § 58.136 Rejected milk. A plant shall reject specific milk from a producer if the milk fails to...

  11. 7 CFR 58.136 - Rejected milk.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Rejected milk. 58.136 Section 58.136 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Milk § 58.136 Rejected milk. A plant shall reject specific milk from a producer if the milk fails...

  12. Characterization and optimization of membrane inlets for a miniature ion trap mass spectrometer operating at a high background pressure of humid air

    NASA Astrophysics Data System (ADS)

    Janfelt, Christian; Graesboll, Rune; Lauritsen, Frants R.

    2008-09-01

    A 10-kg handheld ion trap mass spectrometer, the Mini10, operating at a high background pressure (10-4 Torr range) of humid air was characterized and optimized with respect to the use of membrane inlets. Both flat sheet and tubular membrane inlet configurations in different dimensions were tested using aqueous solutions and inlet temperatures ranging from 25 to 90 °C. The results show that both the absolute ion abundances and the relative abundance of ions in the recorded spectra of volatile organic compounds were highly influenced by the pressure in the vacuum chamber. At elevated pressures the signal intensities dropped, and a shift from primarily electron ionization to primarily chemical ionization was observed. For some chemicals unexpected high-intensity water adduct ions were observed, as confirmed by MS/MS experiments. The pressure effects were found to be correlated with the ionization potential of the analytes, the higher the ionization potential the stronger the effects. Since the pressure in the vacuum chamber is determined by both the membrane dimensions and the temperature of the inlet, the optimization of the membrane inlet is a matter of balancing membrane dimensions and inlet temperature such that both a maximal intensity and an acceptable short response time are achieved simultaneously. In contrast to what is observed for benchtop instruments, elevated inlet temperatures may lead to reduced signal intensity, and the use of a thicker membrane may increase signal intensity. Under all circumstances we found that a linear relationship between signal intensity and sample concentration was observed over at least two orders of magnitude as long as the operational conditions of the system was kept constant. The pressure effects described here are likely to be general for all miniature ion trap mass spectrometers using low performance vacuum pumps.

  13. Are you being rejected or excluded? Insights from neuroimaging studies using different rejection paradigms.

    PubMed

    Premkumar, Preethi

    2012-12-01

    Rejection sensitivity is the heightened tendency to perceive or anxiously expect disengagement from others during social interaction. There has been a recent wave of neuroimaging studies of rejection. The aim of the current review was to determine key brain regions involved in social rejection by selectively reviewing neuroimaging studies that employed one of three paradigms of social rejection, namely social exclusion during a ball-tossing game, evaluating feedback about preference from peers and viewing scenes depicting rejection during social interaction. Across the different paradigms of social rejection, there was concordance in regions for experiencing rejection, namely dorsal anterior cingulate cortex (ACC), subgenual ACC and ventral ACC. Functional dissociation between the regions for experiencing rejection and those for emotion regulation, namely medial prefrontal cortex, ventrolateral prefrontal cortex (VLPFC) and ventral striatum, was evident in the positive association between social distress and regions for experiencing rejection and the inverse association between social distress and the emotion regulation regions. The paradigms of social exclusion and scenes depicting rejection in social interaction were more adept at evoking rejection-specific neural responses. These responses were varyingly influenced by the amount of social distress during the task, social support received, self-esteem and social competence. Presenting rejection cues as scenes of people in social interaction showed high rejection sensitive or schizotypal individuals to under-activate the dorsal ACC and VLPFC, suggesting that such individuals who perceive rejection cues in others down-regulate their response to the perceived rejection by distancing themselves from the scene.

  14. Cost-effectiveness of optimized background therapy plus maraviroc for previously treated patients with R5 HIV-1 infection from the perspective of the Spanish health care system.

    PubMed

    Moreno, Santiago; González, Juan; Lekander, Ingrid; Martí, Belén; Oyagüez, Itziar; Sánchez-de la Rosa, Rainel; Casado, Miguel Angel

    2010-12-01

    The aim of this work was to evaluate the cost-effectiveness, from the perspective of the Spanish health care system, of optimized background therapy (OBT) plus maraviroc 300 mg BID versus OBT plus placebo in previously treated patients with R5 HIV-1 infection. A lifetime cohort model was developed, based on 24- and 48-week pooled results from the Maraviroc Versus Optimized Therapy in Viremic Antiretroviral Treatment-Experienced Patients (MOTIVATE) studies 1 and 2, to reflect the Spanish health care system's perspective. Treatment duration was based on clinical trial follow-up from MOTIVATE 1 and 2. Clinical data, cohort characteristics, success probability, CD4 increase rate, CD4 cell status link to disease states, and adverse-event probability were taken from the MOTIVATE trials and other published literature. Other input parameters were taken from published sources. Antiretroviral (ARV) costs were derived from local sources. Non-ARV drug costs were obtained from published literature and a cost database. All costs were calculated as year-2009 euros. The annual discount rate was set at 3.0%. The main outcomes were cost per life-year gained (LYG) and cost per quality-adjusted life-year (QALY) gained. Uncertainty was assessed with one-way and probabilistic sensitivity analyses. In the model analysis, adding maraviroc to OBT was associated with an increase of 0.952 LYG and 0.909 QALY. Total costs were €275,970 for maraviroc plus OBT and €254,655 for placebo plus OBT (difference: €21,315). The incremental cost per LYG was €22,398 and the incremental cost per QALY gained was €23,457. The model appeared to be robust for variations in key parameters. Results from the probabilistic sensitivity analyses indicated that the probability of the cost per QALY being below €30,000 was 99%. Despite the limitations of the model, our analysis suggested that OBT plus maraviroc 300 mg BID is a clinically valuable option, and cost-effective from the perspective of the

  15. Diagnosis of Rejection by Analyzing Ventricular Late Potentials in Heart Transplant Patients

    PubMed Central

    Mendes, Vítor Nogueira; Pereira, Telmo Santos; Matos, Vítor Azevedo

    2016-01-01

    Background Heart transplant rejection originates slow and fragmented conduction. Signal-averaged ECG (SAECG) is a stratification method in the risk of rejection. Objective To develop a risk score for rejection, using SAECG variables. Methods We studied 28 transplant patients. First, we divided the sample into two groups based on the occurrence of acute rejection (5 with rejection and 23 without). In a second phase, we divided the sample considering the existence or not of rejection in at least one biopsy performed on the follow-up period (rejection pm1: 18 with rejection and 10 without). Results On conventional ECG, the presence of fibrosis was the only criterion associated with acute rejection (OR = 19; 95% CI = 1.65-218.47; p = 0.02). Considering the rejection pm1, an association was found with the SAECG variables, mainly with RMS40 (OR = 0.97; 95% CI = 0.87-0.99; p = 0.03) and LAS40 (OR = 1.06; 95% IC = 1.01-1.11; p = 0.03). We formulated a risk score including those variables, and evaluated its discriminative performance in our sample. The presence of fibrosis with increasing of LAS40 and decreasing of RMS40 showed a good ability to distinguish between patients with and without rejection (AUC = 0.82; p < 0.01), assuming a cutoff point of sensitivity = 83.3% and specificity = 60%. Conclusion The SAECG distinguished between patients with and without rejection. The usefulness of the proposed risk score must be demonstrated in larger follow-up studies. PMID:26815311

  16. Centered CW interference rejection using spread spectrum techniques

    NASA Technical Reports Server (NTRS)

    Scholtz, R. A.

    1980-01-01

    A mathematical model is developed for the rejection of CW interference by spread spectrum techniques. When this interference is known to be exactly at the carrier frequency of the spread spectrum signal, this information can be used to design optimal IF filtering prior to despreading. The application of this approach to the pilot beam receiver of the Solar Power Satellite is considered as an example.

  17. Fate of articles rejected by Indian Pediatrics.

    PubMed

    Dewan, Pooja; Gupta, Piyush; Shah, Dheeraj

    2010-12-01

    The present study was conducted to determine the fate of manuscripts rejected by Indian Pediatrics (IP), and to identify the factors facilitating publication of a rejected manuscript elsewhere. Database (PubMed, IndMed) and Google searches were performed to trace the manuscripts published elsewhere any time after rejection by Indian Pediatrics in the year 2002. Eighteen per cent of the rejected submissions (62 out of 347) were eventually (till July 2009) published elsewhere. These manuscripts subsequently appeared in 33 different journals; Indian Journal of Pediatrics published the maximum numbers (n=22). Seventy four per cent of the rejected papers were published in journals with a impact factor lesser than Indian Pediatrics. Rejection before initiating peer-review, and rejection on the grounds of over-interpretation of results or poor statistical analysis diminished the chances of subsequent publication, whereas manuscripts rejected on grounds of poor originality or poor language had greater chances of being published elsewhere. Rejection of a manuscript by IP does not preclude publication, but rejected manuscripts are published more often in non-pediatric journals or journals with a lower impact factor, although the occasional exception exists.

  18. Optimism

    PubMed Central

    Carver, Charles S.; Scheier, Michael F.; Segerstrom, Suzanne C.

    2010-01-01

    Optimism is an individual difference variable that reflects the extent to which people hold generalized favorable expectancies for their future. Higher levels of optimism have been related prospectively to better subjective well-being in times of adversity or difficulty (i.e., controlling for previous well-being). Consistent with such findings, optimism has been linked to higher levels of engagement coping and lower levels of avoidance, or disengagement, coping. There is evidence that optimism is associated with taking proactive steps to protect one's health, whereas pessimism is associated with health-damaging behaviors. Consistent with such findings, optimism is also related to indicators of better physical health. The energetic, task-focused approach that optimists take to goals also relates to benefits in the socioeconomic world. Some evidence suggests that optimism relates to more persistence in educational efforts and to higher later income. Optimists also appear to fare better than pessimists in relationships. Although there are instances in which optimism fails to convey an advantage, and instances in which it may convey a disadvantage, those instances are relatively rare. In sum, the behavioral patterns of optimists appear to provide models of living for others to learn from. PMID:20170998

  19. Renal allograft rejection: sonography and scintigraphy

    SciTech Connect

    Singh, A.; Cohen, W.N.

    1980-07-01

    A total of 30 renal allograft patients who had sonographic B scanning and radionuclide studies of the transplant was studied as to whether: (1) the allograft rejection was associated with any consistent and reliable sonographic features and (2) the sonograms complemented the radionuclide studies. Focal areas of decreased parenchymal echogenicity were the most striking and consistent sonographic finding in chymal echogenicity were the most striking and consistens sonographic finding in allograft rejection. This was observed in most of the patients exhibiting moderate or severe rejection, but was frequently absent with mild rejection. Areas of decreased parenchymal echogenicity were not seen during episodes of acute tubular necrosis. Therefore, sonography showing zones of decreased parenchymal echogenicity was complementary to radionuclide studies in the diagnosis of allograft rejection versus acute tubular necrosis. Corticomedullary demarcation was difficult to interpret because of technical variables, and was inconsistently related to rejection in this series.

  20. Renal graft irradiation in acute rejection

    SciTech Connect

    Pilepich, M.V.; Sicard, G.A.; Breaux, S.R.; Etheredge, E.E.; Blum, J.; Anderson, C.B.

    1983-03-01

    To evaluate the effect of graft irradiation in the treatment of acute rejection of renal transplants, a randomized study was conducted from 1978 to 1981. Patients with acute rejection were given standard medical management in the form of intravenous methylprednisolone, and were chosen randomly to receive either graft irradiation (175 rads every other day, to a total of 525 rads) or simulated (sham) irradiation. Eighty-three rejections occurring in 64 grafts were randomized to the protocol. Rejection reversal was recorded in 84.5% of control grafts and 75% of the irradiated grafts. Recurrent rejections were more frequent and graft survival was significantly lower in the irradiated group (22%) than in the control group (54%). Graft irradiation does not appear to be beneficial in the treatment of acute rejection of renal transplants when used in conjunction with high-dose steroids.

  1. Extended active disturbance rejection controller

    NASA Technical Reports Server (NTRS)

    Gao, Zhiqiang (Inventor); Tian, Gang (Inventor)

    2012-01-01

    Multiple designs, systems, methods and processes for controlling a system or plant using an extended active disturbance rejection control (ADRC) based controller are presented. The extended ADRC controller accepts sensor information from the plant. The sensor information is used in conjunction with an extended state observer in combination with a predictor that estimates and predicts the current state of the plant and a co-joined estimate of the system disturbances and system dynamics. The extended state observer estimates and predictions are used in conjunction with a control law that generates an input to the system based in part on the extended state observer estimates and predictions as well as a desired trajectory for the plant to follow.

  2. Extended Active Disturbance Rejection Controller

    NASA Technical Reports Server (NTRS)

    Gao, Zhiqiang (Inventor); Tian, Gang (Inventor)

    2016-01-01

    Multiple designs, systems, methods and processes for controlling a system or plant using an extended active disturbance rejection control (ADRC) based controller are presented. The extended ADRC controller accepts sensor information from the plant. The sensor information is used in conjunction with an extended state observer in combination with a predictor that estimates and predicts the current state of the plant and a co-joined estimate of the system disturbances and system dynamics. The extended state observer estimates and predictions are used in conjunction with a control law that generates an input to the system based in part on the extended state observer estimates and predictions as well as a desired trajectory for the plant to follow.

  3. Fractional active disturbance rejection control.

    PubMed

    Li, Dazi; Ding, Pan; Gao, Zhiqiang

    2016-05-01

    A fractional active disturbance rejection control (FADRC) scheme is proposed to improve the performance of commensurate linear fractional order systems (FOS) and the robust analysis shows that the controller is also applicable to incommensurate linear FOS control. In FADRC, the traditional extended states observer (ESO) is generalized to a fractional order extended states observer (FESO) by using the fractional calculus, and the tracking differentiator plus nonlinear state error feedback are replaced by a fractional proportional-derivative controller. To simplify controller tuning, the linear bandwidth-parameterization method has been adopted. The impacts of the observer bandwidth ωo and controller bandwidth ωc on system performance are then analyzed. Finally, the FADRC stability and frequency-domain characteristics for linear single-input single-output FOS are analyzed. Simulation results by FADRC and ADRC on typical FOS are compared to demonstrate the superiority and effectiveness of the proposed scheme.

  4. Extended Active Disturbance Rejection Controller

    NASA Technical Reports Server (NTRS)

    Gao, Zhiqiang (Inventor); Tian, Gang (Inventor)

    2014-01-01

    Multiple designs, systems, methods and processes for controlling a system or plant using an extended active disturbance rejection control (ADRC) based controller are presented. The extended ADRC controller accepts sensor information from the plant. The sensor information is used in conjunction with an extended state observer in combination with a predictor that estimates and predicts the current state of the plant and a co-joined estimate of the system disturbances and system dynamics. The extended state observer estimates and predictions are used in conjunction with a control law that generates an input to the system based in part on the extended state observer estimates and predictions as well as a desired trajectory for the plant to follow.

  5. [Tubulointerstitial rejection of renal allografts].

    PubMed

    Malušková, Jana; Honsová, Eva

    2015-01-01

    Tubulo-intersticial rejection represents T-cell mediated rejection of kidney allografts with the morphology of immune-mediated interstitial nephritis. Diagnosis is dependent on the histopathological evaluation of a graft biopsy sample. The key morphological features are interstitial inflammatory infiltrate and damage to tubular epithelial cell which in severe cases can result in the ruptures of the tubular basement membranes. The differential diagnosis of tubulo-interstitial rejection includes acute interstitial nephritis and viral inflammatory kidney diseases, mainly polyomavirus nephropathy.

  6. Validation of a Simple Score to Determine Risk of Early Rejection After Pediatric Heart Transplantation

    PubMed Central

    Butts, Ryan J.; Savage, Andrew J.; Atz, Andrew M.; Heal, Elisabeth M.; Burnette, Ali L.; Kavarana, Minoo M.; Bradley, Scott M.; Chowdhury, Shahryar M.

    2015-01-01

    OBJECTIVES This study aimed to develop a reliable and feasible score to assess the risk of rejection in pediatric heart transplantation recipients during the first post-transplant year. BACKGROUND The first post-transplant year is the most likely time for rejection to occur in pediatric heart transplantation. Rejection during this period is associated with worse outcomes. METHODS The United Network for Organ Sharing database was queried for pediatric patients (age <18 years) who underwent isolated orthotopic heart transplantation from January 1, 2000 to December 31, 2012. Transplantations were divided into a derivation cohort (n = 2,686) and a validation (n = 509) cohort. The validation cohort was randomly selected from 20% of transplantations from 2005 to 2012. Covariates found to be associated with rejection (p < 0.2) were included in the initial multivariable logistic regression model. The final model was derived by including only variables independently associated with rejection. A risk score was then developed using relative magnitudes of the covariates’ odds ratio. The score was then tested in the validation cohort. RESULTS A 9-point risk score using 3 variables (age, cardiac diagnosis, and panel reactive antibody) was developed. Mean score in the derivation and validation cohorts were 4.5 ± 2.6 and 4.8 ± 2.7, respectively. A higher score was associated with an increased rate of rejection (score = 0, 10.6% in the validation cohort vs. score = 9, 40%; p < 0.01). In weighted regression analysis, the model-predicted risk of rejection correlated closely with the actual rates of rejection in the validation cohort (R2 = 0.86; p < 0.01). CONCLUSIONS The rejection score is accurate in determining the risk of early rejection in pediatric heart transplantation recipients. The score has the potential to be used in clinical practice to aid in determining the immunosuppressant regimen and the frequency of rejection surveillance in the first post-transplant year. PMID

  7. Association of GSTO2 (N142D) Genetic Polymorphism and Acute Rejection of Liver

    PubMed Central

    Khosravi, M.; Saadat, I.; Karimi, M. H.; Malek Hosseini, S. A.

    2016-01-01

    Background: Acute rejection is the main problem in liver transplantation that occurs in the first days or months of transplantation. It includes histological and cellular rejection. Acute histological rejection is confirmed by biopsy. Glutathione S-transferase family is the most important genes in phase II detoxification working in xenobiotic and drug metabolism. GSTO2 is one of the members of this family. GSTO2 (N142D) polymorphism may influence metabolism of immunosuppressive drugs. Objective: To determine if GSTO2 polymorphism has association with acute liver rejection. Methods: The present study included 120 patients with histological-proven acute liver rejection and 182 patients without acute rejection. Both groups were matched for sex and age. To determine variants of GSTO2, we used polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results: There was a significant association between the GSTO2 genotype and acute liver rejection (NN: OR: 3.642, 95% CI: 1.179–5.444) and (ND: OR: 2.533, 95% CI: 1.672–8.149) compared to those with DD geneotype. Conclusion: Recipients with either NN or ND genotype for GSTO2 are more likely to develop acute liver rejection compared to those with DD genotype. PMID:27721965

  8. Rapid heartbeat, but dry palms: reactions of heart rate and skin conductance levels to social rejection

    PubMed Central

    Iffland, Benjamin; Sansen, Lisa M.; Catani, Claudia; Neuner, Frank

    2014-01-01

    Background: Social rejection elicits negative mood, emotional distress, and neural activity in networks that are associated with physical pain. However, studies assessing physiological reactions to social rejection are rare and results of these studies were found to be ambiguous. Therefore, the present study aimed to examine and specify physiological effects of social rejection. Methods: Participants (n = 50) were assigned to either a social exclusion or inclusion condition of a virtual ball-tossing game (Cyberball). Immediate and delayed physiological [skin conductance level (SCL) and heart rate] reactions were recorded. In addition, subjects reported levels of affect, emotional states, and fundamental needs. Results: Subjects who were socially rejected showed increased heart rates. However, social rejection had no effect on subjects' SCLs. Both conditions showed heightened arousal on this measurement. Furthermore, psychological consequences of social rejection indicated the validity of the paradigm. Conclusions: Our results reveal that social rejection evokes an immediate physiological reaction. Accelerated heart rates indicate that behavior activation rather than inhibition is associated with socially threatening events. In addition, results revealed gender-specific response patterns suggesting that sample characteristics such as differences in gender may account for ambiguous findings of physiological reactions to social rejection. PMID:25221535

  9. Quantum Communication Using Coherent Rejection Sampling

    NASA Astrophysics Data System (ADS)

    Anshu, Anurag; Devabathini, Vamsi Krishna; Jain, Rahul

    2017-09-01

    Compression of a message up to the information it carries is key to many tasks involved in classical and quantum information theory. Schumacher [B. Schumacher, Phys. Rev. A 51, 2738 (1995), 10.1103/PhysRevA.51.2738] provided one of the first quantum compression schemes and several more general schemes have been developed ever since [M. Horodecki, J. Oppenheim, and A. Winter, Commun. Math. Phys. 269, 107 (2007); , 10.1007/s00220-006-0118-xI. Devetak and J. Yard, Phys. Rev. Lett. 100, 230501 (2008); , 10.1103/PhysRevLett.100.230501A. Abeyesinghe, I. Devetak, P. Hayden, and A. Winter, Proc. R. Soc. A 465, 2537 (2009), 10.1098/rspa.2009.0202]. However, the one-shot characterization of these quantum tasks is still under development, and often lacks a direct connection with analogous classical tasks. Here we show a new technique for the compression of quantum messages with the aid of entanglement. We devise a new tool that we call the convex split lemma, which is a coherent quantum analogue of the widely used rejection sampling procedure in classical communication protocols. As a consequence, we exhibit new explicit protocols with tight communication cost for quantum state merging, quantum state splitting, and quantum state redistribution (up to a certain optimization in the latter case). We also present a port-based teleportation scheme which uses a fewer number of ports in the presence of information about input.

  10. Rejection and Depression: Prospective and Contemporaneous Analyses.

    ERIC Educational Resources Information Center

    Lefkowitz, Monroe M.; Tesiny, Edward P.

    1984-01-01

    Three studies explore the relationship between parental rejection during childhood and manifestations of depression both then and in young adulthood. With regard to rejection, findings support the general hypothesis that deprivation is an etiological factor in adult depression. (Author/RH)

  11. Who Doesn't Reject the Rejectee?

    ERIC Educational Resources Information Center

    Cockriel, Irwin W.; Fox, Randy J.

    1976-01-01

    This article reports on the utility of sociometrics for the teacher, particularly in determining who will not reject a generally rejected classmate. A study on teachers' ability to predict such students indicated teachers were not very good at predicting either rejectees, or accepting students. Implications and suggestions are discussed. (NG)

  12. PEER ACCEPTANCE-REJECTION AND PERSONALITY DEVELOPMENT.

    ERIC Educational Resources Information Center

    SELLS, S.B.; AND OTHERS

    THIS REPORT PRESENTS THE RESULTS OF A 5-YEAR RESEARCH PROGRAM WHICH ANALYZED MANY OF THE CORRELATES OF PEER ACCEPTANCE-REJECTION IN A SERIES OF STUDIES INVOLVING 37,913 SCHOOL CHILDREN, AGES 9 TO 12 YEARS. PEER ACCEPTANCE-REJECTION WAS INVESTIGATED THROUGH THE USE OF A PEER RATING SCALE AND A TEACHER RATING SCALE. A NUMBER OF METHODOLOGICAL…

  13. Rejection and Depression: Prospective and Contemporaneous Analyses.

    ERIC Educational Resources Information Center

    Lefkowitz, Monroe M.; Tesiny, Edward P.

    1984-01-01

    Three studies explore the relationship between parental rejection during childhood and manifestations of depression both then and in young adulthood. With regard to rejection, findings support the general hypothesis that deprivation is an etiological factor in adult depression. (Author/RH)

  14. 21 CFR 1230.47 - Rejected containers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Rejected containers. 1230.47 Section 1230.47 Food... FEDERAL CAUSTIC POISON ACT Imports § 1230.47 Rejected containers. (a) In all cases where the containers... notification to the importer that the containers must be exported under customs supervision within 3...

  15. How rejection of essences expresses despair.

    PubMed

    Tougas, C T

    1999-07-01

    The Self and the ego in Jung's psychology are an instance of what Edmund Husserl called a 'double intentionality': one tending toward meaning is distinct from another tending toward meaning, yet they are reciprocally inseparable from each other. As perception in a present moment and memory of a past are impossible without each other, so an intending of ego and that of Self are impossible without each other. Accompanying the ego (mostly in the background) during each moment of time is a tending towards a particular Idea or essence. This reciprocity is expressed in a unique way over a lifetime and is like the relation of mother and child, and so it is important for all of us born of women to retain a sense of essences and the fullness of Self. 'Constructivism', however, is a current belief held by some feminists, and it influences both theorizing and practice in analytical psychology. It involves a rejection of essences, a revision of Jung's Idea of Self, and an attempt to conduct analysis without reference to an intentional subjective Self. Such constructivist revision expresses a despair both about essences as Ideas and about Self as intentional and subjective. It is despair over Self in a Kierkegaardian sense.

  16. An Evolutionary Perspective on Mate Rejection.

    PubMed

    Kelly, Ashleigh J; Dubbs, Shelli L; Barlow, Fiona Kate

    2016-01-01

    We argue that mate rejection and ex-partner relationships are important, multifaceted topics that have been underresearched in social and evolutionary psychology. Mate rejection and relationship dissolution are ubiquitous and form integral parts of the human experience. Both also carry with them potential risks and benefits to our fitness and survival. Hence, we expect that mate rejection would have given rise to evolved behavioral and psychological adaptations. Herein, we outline some of the many unanswered questions in evolutionary psychology on these topics, at each step presenting novel hypotheses about how men and women should behave when rejecting a mate or potential mate or in response to rejection. We intend these hypotheses and suggestions for future research to be used as a basis for enriching our understanding of human mating from an evolutionary perspective.

  17. Antibody-Mediated Lung Transplant Rejection

    PubMed Central

    Hachem, Ramsey

    2012-01-01

    Antibody-mediated rejection after lung transplantation remains enigmatic. However, emerging evidence over the past several years suggests that humoral immunity plays an important role in allograft rejection. Indeed, the development of donor-specific antibodies after transplantation has been identified as an independent risk factor for acute cellular rejection and bronchiolitis obliterans syndrome. Furthermore, cases of acute antibody-mediated rejection resulting in severe allograft dysfunction have been reported, and these demonstrate that antibodies can directly injure the allograft. However, the incidence and toll of antibody-mediated rejection are unknown because there is no widely accepted definition and some cases may be unrecognized. Clearly, humoral immunity has become an important area for research and clinical investigation. PMID:23002428

  18. Self-excitation in Francis runner during load rejection

    NASA Astrophysics Data System (ADS)

    Moisan, É.; Giacobbi, D.-B.; Gagnon, M.; Léonard, F.

    2014-03-01

    Typically, transients such as load rejection generate only a few high vibration cycles in Francis runners. However, in the cases presented in this study, a sustained vibration around a natural frequency was observed on three (3) homologous Francis runners of different sizes during such events. The first two (2) runners were equipped with strain gauges on the blades and displacement sensors positioned circumferentially in the bottom ring and head cover around the runner labyrinth seals. The third runner was monitored only with displacement sensors on non-rotating components. The data from the first two (2) runners provided a better understanding of the parameters influencing the appearance of the high amplitude vibrations and allowed the implementation of a test plan to circumvent the phenomenon during commissioning of the third runner. Based on the measured data, the distributor's closing parameters were optimized to eliminate the vibration observed during load rejection on most of the operating range and reduce it significantly at full load.

  19. Active disturbance rejection in large flexible space structures

    NASA Technical Reports Server (NTRS)

    Parlos, Alexander G.; Sunkel, John W.

    1990-01-01

    The design of an active control law for the rejection of persistent disturbances, in large space structures is presented. The control system design approach is based on a deterministic model of the disturbances and it optimizes the magnitude of the disturbance that the structure can tolerate without violating certain predetermined constraints. In addition to closed-loop stability, the explicit treatment of state, control, and control rate constraints, such as structural displacement and control actuator effort, guarantees that the final design will exhibit desired performance characteristics. The technique is applied to a simple two-bay truss structure, and its response is compared with that obtained using a linear-quadratic-Gaussian/loop-transfer-recovery (LQG/LTR) compensator. Preliminary results indicate that the proposed control system can reject persistent disturbances of greater magnitude by utilizing most of the available control, while limiting the structural displacements to within desired tolerances.

  20. Simulation of the transient processes of load rejection under different accident conditions in a hydroelectric generating set

    NASA Astrophysics Data System (ADS)

    Guo, W. C.; Yang, J. D.; Chen, J. P.; Peng, Z. Y.; Zhang, Y.; Chen, C. C.

    2016-11-01

    Load rejection test is one of the essential tests that carried out before the hydroelectric generating set is put into operation formally. The test aims at inspecting the rationality of the design of the water diversion and power generation system of hydropower station, reliability of the equipment of generating set and the dynamic characteristics of hydroturbine governing system. Proceeding from different accident conditions of hydroelectric generating set, this paper presents the transient processes of load rejection corresponding to different accident conditions, and elaborates the characteristics of different types of load rejection. Then the numerical simulation method of different types of load rejection is established. An engineering project is calculated to verify the validity of the method. Finally, based on the numerical simulation results, the relationship among the different types of load rejection and their functions on the design of hydropower station and the operation of load rejection test are pointed out. The results indicate that: The load rejection caused by the accident within the hydroelectric generating set is realized by emergency distributing valve, and it is the basis of the optimization for the closing law of guide vane and the calculation of regulation and guarantee. The load rejection caused by the accident outside the hydroelectric generating set is realized by the governor. It is the most efficient measure to inspect the dynamic characteristics of hydro-turbine governing system, and its closure rate of guide vane set in the governor depends on the optimization result in the former type load rejection.

  1. Nerve Regeneration in Rat Limb Allografts: Evaluation of Acute Rejection Rescue

    PubMed Central

    Yan, Ying; MacEwan, Matthew R.; Hunter, Daniel A.; Farber, Scott; Newton, Piyaraj; Tung, Thomas H.; Mackinnon, Susan E.; Johnson, Philip J.

    2013-01-01

    Background Successful nerve regeneration is critical to the functional success of composite tissue allografts (CTA). The present study was designed to characterize the effect of acute rejection on nerve regeneration and functional recovery in the setting of orthotopic limb transplantation. Methods A rat orthotopic limb transplantation model was used to evaluate the effects of acute rejection on nerve regeneration and motor recovery. Continuous administration of FK506 (Full suppression), administration of FK506 for the first 8 of 12 weeks (Late rejection), or delayed administration of FK506 / dexamethasone following noticeable rejection (Early rejection) was used to preclude or induce rejection following limb transplantation. Twelve weeks postoperatively, nerve regeneration was assessed via histomorphometric analysis of explanted sciatic nerve, and motor recovery was assessed via evoked muscle force measurement in extensor digitorum longus (EDL) muscle. Results A single episode of acute rejection that occurs immediately or late after reconstruction does not significantly alter the number of regenerating axonal fibers. Acute rejection occurring late after reconstruction adversely affects EDL muscle function in CTA. Conclusion Collected data reinforces that adequate immunosuppressant administration in cases of allogeneic limb transplantation ensures levels of nerve regeneration and motor functional recovery equivalent to that of syngeneic transplants. Prompt rescue following acute rejection was further demonstrated not to significantly affect nerve regeneration and functional recovery post-operatively. However, instances of acute rejection that occur late after reconstruction affect graft function. In total, the present study begins to characterize the effect of immunosuppression regimens on nerve regeneration and motor recovery in the setting of CTA. PMID:23542267

  2. High-Common-Mode-Rejection Differential Amplifier

    NASA Technical Reports Server (NTRS)

    Lukens, F. E.

    1984-01-01

    High-common-mode-rejection differential amplifier amplifies low-level signals in presence of high frequency noise. Amplifier used in power system requiring current monitoring on high side of high-voltage powerline.

  3. Enhanced pyrite rejection in coal flotation

    SciTech Connect

    Tao, D.P.; Lu, M.X.; Richardson, P.E.; Luttrell, G.H.; Adel, G.T.; Yoon, R.H.

    1994-12-31

    Difficulties in rejecting pyrite from coal by flotation primarily result from two mechanisms of particle recovery: attachment and middlings. Attachment of pyrite is the consequence of surface hydrophobicity induced by superficial oxidation; middlings that can float readily are caused by incomplete liberation of pyrite from coal. New flotation schemes have been developed to enhance pyrite rejection. They are referred to as Electrochemically-Enhanced Sulfur Rejection (EESR) and Polymer-Enhanced Sulfur Rejection (PESR) processes. In the EESR process, the formation of hydrophobic products is prevented by electrochemical techniques in which active metals are used as sacrificial anodes to cathodically protect pyrite from oxidation; in the PESR process, hydrophilic polymers is used to mask coal in middlings by specific adsorption on pyrite, and thus depress coal-pyrite middlings.

  4. Mechanisms of chronic rejection in cardiothoracic transplantation

    PubMed Central

    Weiss, Matthew J.; Madsen, Joren C.; Rosengard, Bruce R.; Allan, James S.

    2010-01-01

    Despite significant improvements in early post-transplantation survival rates, long-term patient and graft survival have remained poor, due in large part to the vexing problem of chronic allograft rejection. Attempts to combat this problem with intensification of immunosuppression have led to concomitant increases in the rates of fatal malignancies and infections. In cardiac transplantation, chronic rejection is manifested primarily by a disease entity known as cardiac allograft vasculopathy, an occlusive narrowing of the coronary vessels. In lung transplantation, chronic rejection is typified by obliterative bronchiolitis, an airflow limiting narrowing of the bronchioles. From an immunologic standpoint, chronic rejection is believed to be the end result of repeated immune and non-immune insults to the graft. This review examines the pathophysiology of heart and lung chronic, with emphasis on both immune and non-immune causes. PMID:17981771

  5. HLA-DQ Mismatches and Rejection in Kidney Transplant Recipients

    PubMed Central

    Chapman, Jeremy R.; Coates, Patrick T.; Lewis, Joshua R.; Russ, Graeme R.; Watson, Narelle; Holdsworth, Rhonda; Wong, Germaine

    2016-01-01

    Background and objectives The current allocation algorithm for deceased donor kidney transplantation takes into consideration HLA mismatches at the ABDR loci but not HLA mismatches at other loci, including HLA-DQ. However, the independent effects of incompatibilities for the closely linked HLA-DQ antigens in the context of HLA-DR antigen matched and mismatched allografts are uncertain. We aimed to determine the effect of HLA-DQ mismatches on renal allograft outcomes. Design, setting, participants, & measurements Using data from the Australia and New Zealand Dialysis and Transplant Registry, we examined the association between HLA-DQ mismatches and acute rejections in primary live and deceased donor kidney transplant recipients between 2004 and 2012 using adjusted Cox regression models. Results Of the 788 recipients followed for a median of 2.8 years (resulting in 2891 person-years), 321 (40.7%) and 467 (59.3%) received zero and one or two HLA-DQ mismatched kidneys, respectively. Compared with recipients who have received zero HLA-DQ mismatched kidneys, those who have received one or two HLA-DQ mismatched kidneys experienced greater numbers of any rejection (50 of 321 versus 117 of 467; P<0.01), late rejections (occurring >6 months post-transplant; 8 of 321 versus 27 of 467; P=0.03), and antibody-mediated rejections (AMRs; 12 of 321 versus 38 of 467; P=0.01). Compared with recipients of zero HLA-DQ mismatched kidneys, the adjusted hazard ratios for any and late rejections in recipients who had received one or two HLA-DQ mismatched kidneys were 1.54 (95% confidence interval [95% CI], 1.08 to 2.19) and 2.85 (95% CI, 1.05 to 7.75), respectively. HLA-DR was an effect modifier between HLA-DQ mismatches and AMR (P value for interaction =0.02), such that the association between HLA-DQ mismatches and AMR was statistically significant in those who have received one or two HLA-DR mismatched kidneys, with adjusted hazard ratio of 2.50 (95% CI, 1.05 to 5.94). Conclusions HLA

  6. How to get your paper rejected.

    PubMed

    Chernick, Victor

    2008-03-01

    This paper focuses on the main problems that authors of rejected papers have had in their submissions to Pediatric Pulmonology over the past 5 years or so. It is intended as a teaching tool for residents, fellows, allied health personnel, practicing physicians and even some academic physicians who need a refresher on what goes wrong and how they may avoid rejection of their labor. The approach is somewhat lighthearted but nevertheless the message is quite serious.

  7. Thallium kinetics in rat cardiac transplant rejection

    SciTech Connect

    Barak, J.H.; LaRaia, P.J.; Boucher, C.A.; Fallon, J.T.; Buckley, M.J.

    1988-04-01

    Cardiac transplant rejection is a very complex process involving both cellular and vascular injury. Recently, thallium imaging has been used to assess acute transplant rejection. It has been suggested that changes in thallium kinetics might be a sensitive indicator of transplant rejection. Accordingly, thallium kinetics were assessed in vivo in acute untreated rat heterotopic (cervical) transplant rejection. Male Lewis rats weighing 225-250 g received heterotopic heart transplants from syngeneic Lewis rats (group A; n = 13), or allogeneic Brown Norway rats (group B; n = 11). Rats were imaged serially on the 2nd and the 7th postoperative days. Serial cardiac thallium content was determined utilizing data collected every 150 sec for 2 hr. The data were fit to a monoexponential curve and the decay rate constant (/sec) derived. By day 7 all group B hearts had histological evidence of severe acute rejection, and demonstrated decreased global contraction. Group A hearts showed normal histology and contractility. However, thallium uptakes and washout of the two groups were the same. Peak thallium uptake of group B was +/- 3758 1166 counts compared with 3553 +/- 950 counts in the control group A (P = 0.6395); The 2-hr percentage of washout was 12.1 +/- 1.04 compared with 12.1 +/- 9.3 (P = 1.0000); and the decay constant was -0.00002065 +/- 0.00001799 compared with -0.00002202 +/- 0.00001508 (P = 0.8409). These data indicate that in vivo global thallium kinetics are preserved during mild-to-severe acute transplant rejection. These findings suggest that the complex cellular and extracellular processes of acute rejection limit the usefulness of thallium kinetics in the detection of acute transplant rejection.

  8. Interpersonal rejection as a determinant of anger and aggression.

    PubMed

    Leary, Mark R; Twenge, Jean M; Quinlivan, Erin

    2006-01-01

    This article reviews the literature on the relationship between interpersonal rejection and aggression. Four bodies of research are summarized: laboratory experiments that manipulate rejection, rejection among adults in everyday life, rejection in childhood, and individual differences that may moderate the relationship. The theoretical mechanisms behind the effect are then explored. Possible explanations for why rejection leads to anger and aggression include: rejection as a source of pain, rejection as a source of frustration, rejection as a threat to self-esteem, mood improvement following aggression, aggression as social influence, aggression as a means of reestablishing control, retribution, disinhibition, and loss of self-control.

  9. Perturbations in the Urinary Exosome in Transplant Rejection

    SciTech Connect

    Sigdel, Tara K.; NG, Yolanda; Lee, Sangho; Nicora, Carrie D.; Qian, Weijun; Smith, Richard D.; Camp, David G.; Sarwal, Minnie M.

    2015-01-05

    Background: Urine exosomes, vesicles exocytosed into urine by all renal epithelial cell types, occur under normal physiologic and disease states. Exosome contents may mirror disease-specific proteome perturbations in kidney injury. Analysis methodologies for the exosomal fraction of the urinary proteome were developed and for comparing the urinary exosomal fraction versus unfractionated proteome for biomarker discovery. Methods: Urine exosomes were isolated by centrifugal filtration from mid-stream, second morning void, urine samples collected from kidney transplant recipients with and without biopsy matched acute rejection. The proteomes of unfractionated whole urine (Uw) and urine exosomes (Uexo) underwent mass spectrometry-based quantitative proteomics analysis. The proteome data were analyzed for significant differential protein abundances in acute rejection (AR). Results: Identifications of 1018 and 349 proteins, Uw and Uexo fractions, respectively, demonstrated a 279 protein overlap between the two urinary compartments with 25%(70) of overlapping proteins unique to Uexoand represented membrane bound proteins (p=9.31e-7). Of 349 urine exosomal proteins identified in transplant patients 220 were not previously identified in the normal urine exosomal fraction. Uexo proteins (11), functioning in the inflammatory / stress response, were more abundant in patients with biopsy-confirmed acute rejection, 3 of which were exclusive to Uexo. Uexo AR-specific biomarkers (8) were also detected in Uw, but since they were observed at significantly lower abundances in Uw, they were not significant for AR in Uw. Conclusions: A rapid urinary exosome isolation method and quantitative measurement of enriched Uexo proteins was applied. Urine proteins specific to the exosomal fraction were detected either in unfractionated urine (at low abundances) or by Uexo fraction analysis. Perturbed proteins in the exosomal compartment of urine collected from kidney transplant patients were

  10. Image rejects in general direct digital radiography.

    PubMed

    Hofmann, Bjørn; Rosanowsky, Tine Blomberg; Jensen, Camilla; Wah, Kenneth Hong Ching

    2015-10-01

    The number of rejected images is an indicator of image quality and unnecessary imaging at a radiology department. Image reject analysis was frequent in the film era, but comparably few and small studies have been published after converting to digital radiography. One reason may be a belief that rejects have been eliminated with digitalization. To measure the extension of deleted images in direct digital radiography (DR), in order to assess the rates of rejects and unnecessary imaging and to analyze reasons for deletions, in order to improve the radiological services. All exposed images at two direct digital laboratories at a hospital in Norway were reviewed in January 2014. Type of examination, number of exposed images, and number of deleted images were registered. Each deleted image was analyzed separately and the reason for deleting the image was recorded. Out of 5417 exposed images, 596 were deleted, giving a deletion rate of 11%. A total of 51.3% were deleted due to positioning errors and 31.0% due to error in centering. The examinations with the highest percentage of deleted images were the knee, hip, and ankle, 20.6%, 18.5%, and 13.8% respectively. The reject rate is at least as high as the deletion rate and is comparable with previous film-based imaging systems. The reasons for rejection are quite different in digital systems. This falsifies the hypothesis that digitalization would eliminates rejects. A deleted image does not contribute to diagnostics, and therefore is an unnecessary image. Hence, the high rates of deleted images have implications for management, training, education, as well as for quality.

  11. The fate of triaged and rejected manuscripts.

    PubMed

    Zoccali, Carmine; Amodeo, Daniela; Argiles, Angel; Arici, Mustafa; D'arrigo, Graziella; Evenepoel, Pieter; Fliser, Danilo; Fox, Jonathan; Gesualdo, Loreto; Jadoul, Michel; Ketteler, Markus; Malyszko, Jolanta; Massy, Ziad; Mayer, Gert; Ortiz, Alberto; Sever, Mehmet; Vanholder, Raymond; Vinck, Caroline; Wanner, Christopher; Więcek, Andrzej

    2015-12-01

    In 2011, Nephrology Dialysis and Transplantation (NDT) established a more restrictive selection process for manuscripts submitted to the journal, reducing the acceptance rate from 25% (2008-2009) to currently about 12-15%. To achieve this goal, we decided to score the priority of manuscripts submitted to NDT and to reject more papers at triage than in the past. This new scoring system allows a rapid decision for the authors without external review. However, the risk of such a restrictive policy may be that the journal might fail to capture important studies that are eventually published in higher-ranked journals. To look into this problem, we analysed random samples of papers (∼10%) rejected by NDT in 2012. Of the papers rejected at triage and those rejected after regular peer review, 59 and 61%, respectively, were accepted in other journals. A detailed analysis of these papers showed that only 4 out of 104 and 7 out of 93 of the triaged and rejected papers, respectively, were published in journals with an impact factor higher than that of NDT. Furthermore, for all these papers, independent assessors confirmed the evaluation made by the original reviewers. The number of citations of these papers was similar to that typically obtained by publications in the corresponding journals. Even though the analyses seem reassuring, previous observations made by leading journals warn that the risk of 'big misses', resulting from selective editorial policies, remains a real possibility. We will therefore continue to maintain a high degree of alertness and will periodically track the history of manuscripts rejected by NDT, particularly papers that are rejected at triage by our journal. © The Author 2015. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

  12. The fate of triaged and rejected manuscripts

    PubMed Central

    Zoccali, Carmine; Amodeo, Daniela; Argiles, Angel; Arici, Mustafa; D'arrigo, Graziella; Evenepoel, Pieter; Fliser, Danilo; Fox, Jonathan; Gesualdo, Loreto; Jadoul, Michel; Ketteler, Markus; Malyszko, Jolanta; Massy, Ziad; Mayer, Gert; Ortiz, Alberto; Sever, Mehmet; Vanholder, Raymond; Vinck, Caroline; Wanner, Christopher; Więcek, Andrzej

    2015-01-01

    In 2011, Nephrology Dialysis and Transplantation (NDT) established a more restrictive selection process for manuscripts submitted to the journal, reducing the acceptance rate from 25% (2008–2009) to currently about 12–15%. To achieve this goal, we decided to score the priority of manuscripts submitted to NDT and to reject more papers at triage than in the past. This new scoring system allows a rapid decision for the authors without external review. However, the risk of such a restrictive policy may be that the journal might fail to capture important studies that are eventually published in higher-ranked journals. To look into this problem, we analysed random samples of papers (∼10%) rejected by NDT in 2012. Of the papers rejected at triage and those rejected after regular peer review, 59 and 61%, respectively, were accepted in other journals. A detailed analysis of these papers showed that only 4 out of 104 and 7 out of 93 of the triaged and rejected papers, respectively, were published in journals with an impact factor higher than that of NDT. Furthermore, for all these papers, independent assessors confirmed the evaluation made by the original reviewers. The number of citations of these papers was similar to that typically obtained by publications in the corresponding journals. Even though the analyses seem reassuring, previous observations made by leading journals warn that the risk of ‘big misses’, resulting from selective editorial policies, remains a real possibility. We will therefore continue to maintain a high degree of alertness and will periodically track the history of manuscripts rejected by NDT, particularly papers that are rejected at triage by our journal. PMID:26597920

  13. Rapid optimized separation of bromide in serum samples with capillary zone electrophoresis by using glycerol as additive to the background electrolyte.

    PubMed

    Pascali, Jennifer P; Liotta, Eloisa; Gottardo, Rossella; Bortolotti, Federica; Tagliaro, Franco

    2009-04-10

    After decades of neglect, bromide has recently been re-introduced in therapy as an effective anti-epileptic drug. The present paper describes the methodological optimization and validation of a method based on capillary zone electrophoresis for the rapid determination of bromide in serum using a high-viscosity buffer and a short capillary (10 cm). The optimized running buffer was composed of 90 mM sodium tetraborate, 10mM sodium chloride, pH 9.24 and 25% glycerol. The separation was carried out at 25 kV at a temperature of 20 degrees C. Detection was by direct UV absorption at 200 nm wavelength. The limit of detection (signal-to-noise ratio=5) in serum was 0.017 mM. The precision of the method was verified in blank serum samples spiked with bromide, obtaining intra-day and day-to-day tests, relative standard deviation values

  14. Role of interleukin-17A in early graft rejection after orthotopic lung transplantation in mice

    PubMed Central

    Chen, Qi-Rui; Wang, Li-Feng; Xia, Si-Si; Zhang, Ya-Mei; Xu, Jiang-Nan

    2016-01-01

    Background The cellular and molecular mechanisms underlying lung allograft rejection remain poorly understood. We investigated the potential role of interleukin (IL)-17A in lung transplant rejection in a mouse model, because previous studies in clinical and rodent models have implicated IL-17A in both acute and chronic rejection. Methods To generate an orthotopic lung transplantation model, lungs from C57BL/6 or BALB/c mice were transplanted into C57BL/6 mice (isograft and allograft models, respectively). The effects of anti-IL-17A treatment in allograft recipients were investigated. The histological features and rejection status of isografts and allografts were assessed at 3, 7, and 28 days after transplantation, and differences in graft infiltrating cells and mRNA expression of relevant cytokines were quantified at 3 and 7 days after transplantation. Results As expected, isografts showed no obvious signs of rejection, whereas allografts exhibited minimal-to-mild rejection (grade A1–A2) by day 3 and moderate-to-severe rejection (grade A3–A4) by day 7, without evidence of obliterative bronchiolitis (OB). However, by 28 days, evidence of OB was observed in 67% (2/3) of allografts and severe rejection (grade A4) was observed in all. IL-17 mRNA expression in allografts was increased with rejection, and interferon (IFN)-γ and IL-6 mRNA expression levels followed a similar pattern. In contrast, IL-22 expression in allografts was only slightly increased. Antibody (Ab) neutralization of IL-17A diminished the signs of acute rejection at 7 days after transplantation in allografts, and this early protection was accompanied by a decrease in cellular stress according to histological evaluation, suggesting the involvement of IL-17A in the development of early post-transplantation lesions. Conclusions Our data indicate that IL-17A is important in the pathophysiology of allograft rejection, and neutralization of IL-17A is a potential therapeutic strategy to preventing lung

  15. Rejection of pharmaceuticals by nanofiltration (NF) membranes: Effect of fouling on rejection behaviour

    NASA Astrophysics Data System (ADS)

    Mahlangu, T. O.; Msagati, T. A. M.; Hoek, E. M. V.; Verliefde, A. R. D.; Mamba, B. B.

    The aim of this study was to investigate the effects of membrane fouling by sodium alginate, latex and a combination of alginate + latex on the rejection behaviour of salts and organics. Sodium chloride and caffeine were selected to represent salts and organics, respectively. The effects of the presence of calcium chloride on the fouling behaviour and rejection of solutes were investigated. The results revealed that the salt rejection by virgin membranes was 47% while that of caffeine was 85%. Fouling by alginate, latex and combined alginate-latex resulted in flux decline of 25%, 37% and 17%, respectively. The addition of Ca2+ aggravated fouling and resulted in further flux decline to 37%. Fouling decreased salt rejection, an observation that was further aggravated by the addition on Ca2+. However, it was also observed that fouling with alginate and calcium and with latex and calcium minimised salt rejection by 30% and 31%, respectively. This reduction in salt rejection was attributed to the decrease in permeate flux (since rejection is a function of flux). There was a slight increase in caffeine rejection when the membrane was fouled with latex particles. Moreover, the presence of foulants on the membrane resulted in a decrease in the surface charge of the membrane. The results of this study have shown that the NF 270 membrane can be used to treat water samples contaminated with caffeine and other organic compounds that have physicochemical properties similar to those of caffeine.

  16. Understanding Rejection between First-and-Second-Grade Elementary Students through Reasons Expressed by Rejecters

    PubMed Central

    García Bacete, Francisco J.; Carrero Planes, Virginia E.; Marande Perrin, Ghislaine; Musitu Ochoa, Gonzalo

    2017-01-01

    Objective: The aim of this research was to obtain the views of young children regarding their reasons for rejecting a peer. Method: To achieve this goal, we conducted a qualitative study in the context of theory building research using an analysis methodology based on Grounded Theory. The collected information was extracted through semi-structured individual interviews from a sample of 853 children aged 6 from 13 urban public schools in Spain. Results: The children provided 3,009 rejection nominations and 2,934 reasons for disliking the rejected peers. Seven reason categories emerged from the analysis. Four categories refer to behaviors of the rejected children that have a cost for individual peers or peer group such as: direct aggression, disturbance of wellbeing, problematic social and school behaviors and dominance behaviors. A further two categories refer to the identities arising from the preferences and choices of rejected and rejecter children and their peers: personal identity expressed through preferences and disliking, and social identity expressed through outgroup prejudices. The “no-behavior or no-choice” reasons were covered by one category, unfamiliarity. In addition, three context categories were found indicating the participants (interpersonal–group), the impact (low–high), and the subjectivity (subjective–objective) of the reason. Conclusion: This study provides researchers and practitioners with a comprehensive taxonomy of reasons for rejection that contributes to enrich the theoretical knowledge and improve interventions for preventing and reducing peer rejection. PMID:28421008

  17. Taste rejection of nonnutritive sweeteners in cats.

    PubMed

    Bartoshuk, L M; Jacobs, H L; Nichols, T L; Hoff, L A; Ryckman, J J

    1975-10-01

    Cats reject saccharin and cyclamate and are indifferent to dulcin, although they, like other mammals, prefer sucrose. The rejection threshold for saccharin found in this experiments, .0001 M, is about 2 log steps lower than a previously reported rejection threshold for sodium saccharin. Water produces a taste in cats adapted to their own saliva. The high sodium saccharin threshold may have resulted because the taste of the sodium saccharin was masked by the taste of the water solvent; however, saccharin may also be somewhat more aversive to the cat than sodium saccharin. Saccharin may produce an aversive taste because it stimulates receptor sites sensitive to substances bitter to man as well as those sensitive to sugars. In addition, saccharin may not be an effective stimulus for all sugar-sensitive sites.

  18. New approaches for dim target detection and clutter rejection

    NASA Astrophysics Data System (ADS)

    Liou, Ren-Jean

    1993-01-01

    This dissertation presents a new method for clutter rejection and dim target track detection from infrared (IR) satellite data using neural networks. A method referred to as 'high order correlation method' is developed which recursively computes the spatio-temporal cross-correlations between data of consecutive scans. The implementation of this scheme using a connectionist network is also proposed. Several important properties of the high order correlation method are established which indicate that the resultant filtered images capture all the target information. Simulation results using this approach show at least 93% clutter rejection under moderate clutter density. Further improvement in the clutter rejection is achieved by modifying the high order correlation method to incorporate the target motion dynamics. The implementation of this 'modified high order correlation' using a high order neural network architecture is also developed. Simulation results indicate at least 97% clutter rejection rate for this method. To test the performance, experimental studies of this modified high order correlations are conducted under various scenarios which include: multiple target detection, continuous mode operation, various background clutter densities, and detection using variable number of scans and order of correlation. This algorithm performs very well even under many difficult operating environments. A new scoring process is developed to improve the discrimination ability of the modified high order correlation scheme by employing velocity and curvature information. This scoring process is then used to identify each individual track in the scene by using the properties of the modified high order correlation method. This modification not only significantly improves the clutter rejection under very dense clutter environment, but also increases the feasibility of using the modified high order correlation method for other areas such as data association target classification

  19. A semi-learning algorithm for noise rejection: an fNIRS study on ADHD children

    NASA Astrophysics Data System (ADS)

    Sutoko, Stephanie; Funane, Tsukasa; Katura, Takusige; Sato, Hiroki; Kiguchi, Masashi; Maki, Atsushi; Monden, Yukifumi; Nagashima, Masako; Yamagata, Takanori; Dan, Ippeita

    2017-02-01

    In pediatrics studies, the quality of functional near infrared spectroscopy (fNIRS) signals is often reduced by motion artifacts. These artifacts likely mislead brain functionality analysis, causing false discoveries. While noise correction methods and their performance have been investigated, these methods require several parameter assumptions that apparently result in noise overfitting. In contrast, the rejection of noisy signals serves as a preferable method because it maintains the originality of the signal waveform. Here, we describe a semi-learning algorithm to detect and eliminate noisy signals. The algorithm dynamically adjusts noise detection according to the predetermined noise criteria, which are spikes, unusual activation values (averaged amplitude signals within the brain activation period), and high activation variances (among trials). Criteria were sequentially organized in the algorithm and orderly assessed signals based on each criterion. By initially setting an acceptable rejection rate, particular criteria causing excessive data rejections are neglected, whereas others with tolerable rejections practically eliminate noises. fNIRS data measured during the attention response paradigm (oddball task) in children with attention deficit/hyperactivity disorder (ADHD) were utilized to evaluate and optimize the algorithm's performance. This algorithm successfully substituted the visual noise identification done in the previous studies and consistently found significantly lower activation of the right prefrontal and parietal cortices in ADHD patients than in typical developing children. Thus, we conclude that the semi-learning algorithm confers more objective and standardized judgment for noise rejection and presents a promising alternative to visual noise rejection

  20. Radiation therapy for renal transplant rejection reactions

    SciTech Connect

    Peeples, W.J.; Wombolt, D.G.; El-Mahdi, A.M.; Turalba, C.I.

    1982-01-01

    Forty-four renal transplant patients were given radiation therapy for severe rejection phenomena. The 29 patients who had only one course of irradiation had a 52.3% successful function rate. Fifteen patients received from two to four courses of irradiation with an ultimate 60% rate of sustained function. Fifty patients who received only steroid and other medical management but no irradiation had a 60% rate of successful renal function. In the irradiation group, no patient whose creatinine level did not respond to radiation therapy maintained a functioning kidney. The data indicate that the overall successful function rate is maintained by radiation therapy in patients who show severe allograft rejection phenomena.

  1. Solar dynamic space power system heat rejection

    NASA Technical Reports Server (NTRS)

    Carlson, A. W.; Gustafson, E.; Mclallin, K. L.

    1986-01-01

    A radiator system concept is described that meets the heat rejection requirements of the NASA Space Station solar dynamic power modules. The heat pipe radiator is a high-reliability, high-performance approach that is capable of erection in space and is maintainable on orbit. Results are present of trade studies that compare the radiator system area and weight estimates for candidate advanced high performance heat pipes. The results indicate the advantages of the dual-slot heat pipe radiator for high temperature applications as well as its weight-reduction potential over the range of temperatures to be encountered in the solar dynamic heat rejection systems.

  2. The Lived Experience of Psoriasis Patients from Social Stigma and Rejection: A Qualitative Study

    PubMed Central

    Ghorbanibirgani, Alireza; Fallahi-Khoshknab, Masoud; Zarea, Kourosh; Abedi, Heidarali

    2016-01-01

    Background Psoriasis is a common, chronic skin disease that causes challenges such as stigma and labeling from both the community and individuals due to its effects on appearance. Objectives The objective of this study was to describe and explain the social stigma and rejection experienced by patients with psoriasis. Patients and Methods The present research is a qualitative study with a hermeneutic phenomenological approach conducted among psoriasis patients referring to the dermatology clinic and ward of Imam Khomeini hospital in Ahvaz, Iran between June and December 2014. In this study, 15 patients with psoriasis were selected by purposeful sampling, and they were asked to express their experience of stigma and rejection. The data were collected through in-depth semi-structured interviews, and Diekelmann and colleagues’ method was used for data analysis. Results After analysis of interviews, four themes were extracted: lack of social support, unrealistic and inappropriate labeling, rejection and isolation, and feeling of absurdity and futility. These can be indicative of the patients’ experience from social stigma and rejection phenomena. Conclusions Patients’ experiences of stigma and rejection phenomena indicated that all aspects of their lives are affected. Moreover, these findings highlight the significance of stigma and rejection concepts in providing better care to these patients. PMID:27656290

  3. 19F MRI Detection of Acute Allograft Rejection with In Vivo Perfluorocarbon Labeling of Immune Cells

    PubMed Central

    Hitchens, T. Kevin; Ye, Qing; Eytan, Danielle F.; Janjic, Jelena M.; Ahrens, Eric T.; Ho, Chien

    2010-01-01

    Current diagnosis of organ rejection following transplantation relies on tissue biopsy, which is not ideal due to sampling limitations and risks associated with the invasive procedure. We have previously shown that cellular MRI of iron-oxide labeled immune-cell infiltration can provide a non-invasive measure of rejection status by detecting areas of hypointensity on T2*-weighted images. In the current study, we tested the feasibility of using a fluorine-based cellular tracer agent to detect macrophage accumulation in rodent models of acute allograft rejection by fluorine-19 (19F) MRI and MRS. This study used two rat models of acute rejection, including abdominal heterotopic cardiac transplant and orthotopic kidney transplant models. Following in vivo labeling of monocytes and macrophages with a commercially available agent containing perfluoro-15-crown-5-ether, we observed 19F-signal intensity in the organs experiencing rejection by 19F MRI, and conventional 1H MRI was used for anatomical context. Immunofluorescense and histology confirmed macrophage labeling. These results are consistent with our previous studies and show the complementary nature of the two cellular imaging techniques. With no background signal, 19F MRI/MRS can provide unambiguous detection of fluorine labeled cells, and may be a useful technique for detecting and quantifying rejection grade in patients. PMID:21305593

  4. Noninvasive assessment for acute allograft rejection in a rat lung transplantation model

    PubMed Central

    Takahashi, Ayuko; Hamakawa, Hiroshi; Sakai, Hiroaki; Zhao, Xiangdong; Chen, Fengshi; Fujinaga, Takuji; Shoji, Tsuyoshi; Bando, Toru; Wada, Hiromi; Date, Hiroshi

    2014-01-01

    Abstract After lung transplantation, early detection of acute allograft rejection is important not only for timely and optimal treatment, but also for the prediction of chronic rejection which is a major cause of late death. Many biological and immunological approaches have been developed to detect acute rejection; however, it is not well known whether lung mechanics correlate with disease severity, especially with pathological rejection grade. In this study, we examined the relationship between lung mechanics and rejection grade development in a rat acute rejection model using the forced oscillation technique, which provides noninvasive assessment of lung function. To this end, we assessed lung resistance and elastance (RL and EL) from implanted left lung of these animals. The perivascular/interstitial component of rejection severity grade (A‐grade) was also quantified from histological images using tissue fraction (TF; tissue + cell infiltration area/total area). We found that TF, RL, and EL increased according to A‐grade. There was a strong positive correlation between EL at the lowest frequency (Elow; EL at 0.5 Hz) and TF (r2 = 0.930). Furthermore, the absolute difference between maximum value of EL (Emax) and Elow (Ehet; Emax − Elow) showed the strong relationship with standard deviation of TF (r2 = 0.709), and A‐grade (Spearman's correlation coefficients; rs = 0.964, P < 0.0001). Our results suggest that the dynamic elastance as well as its frequency dependence have the ability to predict A‐grade. These indexes should prove useful for noninvasive detection and monitoring the progression of disease in acute rejection. PMID:25524280

  5. The Association Between Broad Antigen HLA Mismatches, Eplet HLA Mismatches and Acute Rejection After Kidney Transplantation

    PubMed Central

    Do Nguyen, Hung Thanh; Wong, Germaine; Chapman, Jeremy R.; McDonald, Stephen P.; Coates, Patrick T.; Watson, Narelle; Russ, Graeme R.; D'Orsogna, Lloyd; Lim, Wai Hon

    2016-01-01

    Background Epitope matching, which evaluates mismatched amino acids within antigen-antibody interaction sites (eplets), may better predict acute rejection than broad antigen matching alone. We aimed to determine the association between eplet mismatches and acute rejection in kidney transplant recipients. Methods The association between eplet mismatches, broad antigen mismatches and acute rejection was assessed using adjusted Cox proportional hazard regression. Model discrimination for acute rejection was evaluated using the area under receiver operating characteristic curves. Results Of the 3,499 kidney transplant recipients from 2006 to 2011, the average (SD) number of broad antigen and eplet mismatches were 3.4 (1.7) and 22.8 (12.2), respectively. Compared with 0 to 2 eplet mismatches, the adjusted hazard ratio (HR) for acute rejection among those with 20 or greater eplet mismatches was 2.16 (95% confidence interval [CI], 1.33-3.52; P = 0.001). The adjusted area under the curve for broad antigen mismatches was 0.58 (95% CI, 0.56-0.61), similar to that for eplet mismatches (HR, 0.59; 95% CI, 0.56-0.61; P = 0.365). In recipients who were considered as low immunological risk (0-2 broad antigen HLA-ABDR mismatch), those with 20 or greater eplet mismatches experienced an increased risk of rejection compared to those with less than 20 mismatches (adjusted HR, 1.85; 95% CI, 1.11-3.08; P = 0.019). Conclusions Increasing number of eplet mismatches is associated with acute rejection in kidney transplant recipients. Consideration of eplet HLA mismatches may improve risk stratification for acute rejection in a selected group of kidney transplant candidates. PMID:27990485

  6. Materialistic Values among Chinese Adolescents: Effects of Parental Rejection and Self-Esteem

    ERIC Educational Resources Information Center

    Fu, Xinyuan; Kou, Yu; Yang, Ying

    2015-01-01

    Background: Materialistic values among today's adolescents have been a concern around the world, yet few studies concerning Chinese adolescents' materialistic values have been conducted. Additionally, the joint effects of parental rejection and self-esteem on materialistic values remain unclear. Objective: We examined materialistic values in a…

  7. Materialistic Values among Chinese Adolescents: Effects of Parental Rejection and Self-Esteem

    ERIC Educational Resources Information Center

    Fu, Xinyuan; Kou, Yu; Yang, Ying

    2015-01-01

    Background: Materialistic values among today's adolescents have been a concern around the world, yet few studies concerning Chinese adolescents' materialistic values have been conducted. Additionally, the joint effects of parental rejection and self-esteem on materialistic values remain unclear. Objective: We examined materialistic values in a…

  8. Development of enhanced sulfur rejection processes

    SciTech Connect

    Yoon, R.H.; Luttrell, G.; Adel, G.; Richardson, P.E.

    1993-03-23

    Research at Virginia Tech led to two complementary concepts for improving the removal of inorganic sulfur from much of the Eastern US coals. One controls the surface properties of coal pyrite (FeS[sub 2]) by electrochemical-.potential control, referred to as the Electrochemically Enhanced Sulfur Rejection (EESR) Process: The second controls the flotation of middlings, i.e., particles composed of pyrite with coal inclusions by using polymeric reagents to react with pyrite and convert the middlings to hydrophilic particles, and is termed the Polymer Enhanced Sulfur Rejection (PESR) Process. These new concepts are based on recent research establishing the two main reasons why flotation fails to remove more than about 50% of the pyritic sulfur from coal: superficial oxidization of liberated pyrite to form polysulfide oxidation products so that a part of the liberated pyrite floats with the coal; and hydrophobic coal inclusions in the middlings dominating their flotation so that the middlings also float with the coal. These new pyritic-sulfur rejection processes do not require significant modifications of existing coal preparation facilities, enhancing their adoptability by the coal industry. It is believed that they can be used simultaneously to achieve both free pyrite and locked pyrite rejection.

  9. Automatic Rejection Of Multimode Laser Pulses

    NASA Technical Reports Server (NTRS)

    Tratt, David M.; Menzies, Robert T.; Esproles, Carlos

    1991-01-01

    Characteristic modulation detected, enabling rejection of multimode signals. Monitoring circuit senses multiple longitudinal mode oscillation of transversely excited, atmospheric-pressure (TEA) CO2 laser. Facility developed for inclusion into coherent detection laser radar (LIDAR) system. However, circuit described of use in any experiment where desireable to record data only when laser operates in single longitudinal mode.

  10. Development of enhanced sulfur rejection processes

    SciTech Connect

    Yoon, R.H.; Luttrell, G.H.; Adel, G.T.; Richardson, P.E.

    1996-03-01

    Research at Virginia Tech led to the development of two complementary concepts for improving the removal of inorganic sulfur from many eastern U.S. coals. These concepts are referred to as Electrochemically Enhanced Sulfur Rejection (EESR) and Polymer Enhanced Sulfur Rejection (PESR) processes. The EESR process uses electrochemical techniques to suppress the formation of hydrophobic oxidation products believed to be responsible for the floatability of coal pyrite. The PESR process uses polymeric reagents that react with pyrite and convert floatable middlings, i.e., composite particles composed of pyrite with coal inclusions, into hydrophilic particles. These new pyritic-sulfur rejection processes do not require significant modifications to existing coal preparation facilities, thereby enhancing their adoptability by the coal industry. It is believed that these processes can be used simultaneously to maximize the rejection of both well-liberated pyrite and composite coal-pyrite particles. The project was initiated on October 1, 1992 and all technical work has been completed. This report is based on the research carried out under Tasks 2-7 described in the project proposal. These tasks include Characterization, Electrochemical Studies, In Situ Monitoring of Reagent Adsorption on Pyrite, Bench Scale Testing of the EESR Process, Bench Scale Testing of the PESR Process, and Modeling and Simulation.

  11. Rejection of cowbird eggs by crissal thrashers

    Treesearch

    Deborah M. Finch

    1982-01-01

    Although the "dwarf" race of the Brown-headed Cowbird (Molothrus ater obscurus) is sympatric with the Crissal Thrasher (Toxostoma dorsale) in the lower Colorado River valley, I observed no parasitism in 15 thrasher nests. To determine whether or not the absence of cowbird eggs was caused by egg rejection, I experimentally parasitized nine thrasher nests....

  12. Antimyosin imaging in cardiac transplant rejection

    SciTech Connect

    Johnson, L.L.; Cannon, P.J. )

    1991-09-01

    Fab fragments of antibodies specific for cardiac myosin have been labeled with indium-111 and injected intravenously into animals and into patients with heart transplants. The antibodies, developed by Khaw, Haber, and co-workers, localize in cardiac myocytes that have been damaged irreversibly by ischemia, myocarditis, or the rejection process. After clearance of the labeled antibody from the cardiac blood pool, planar imaging or single photon emission computed tomography is performed. Scintigrams reveal the uptake of the labeled antimyosin in areas of myocardium undergoing transplant rejection. In animal studies, the degree of antimyosin uptake appears to correlate significantly with the degree of rejection assessed at necropsy. In patients, the correlation between scans and pathologic findings from endomyocardial biopsy is not as good, possibly because of sampling error in the endomyocardial biopsy technique. The scan results at 1 year correlate with either late complications (positive) or benign course (negative). Current limitations of the method include slow blood clearance, long half-life of indium-111, and hepatic uptake. Overcoming these limitations represents a direction for current research. It is possible that from these efforts a noninvasive approach to the diagnosis and evaluation of cardiac transplantation may evolve that will decrease the number of endomyocardial biopsies required to evaluate rejection. This would be particularly useful in infants and children. 31 references.

  13. Examining Social Acceptance & Rejection. FPG Snapshot #44

    ERIC Educational Resources Information Center

    FPG Child Development Institute, 2007

    2007-01-01

    This FPG Snapshot summarizes the findings of a study, published in the November 2006 issue of the "Journal of Educational Psychology," that examined whether children with disabilities are accepted or rejected by their classmates in inclusive classrooms. Specifically, the study examined two sets of related questions: (1) Are individual…

  14. Genetic Polymorphism of Interferon Regulatory Factor 5 (IRF5) Correlates with Allograft Acute Rejection of Liver Transplantation

    PubMed Central

    Yu, Xiaobo; Wei, Bajin; Dai, Yifan; Zhang, Min; Wu, Jian; Xu, Xiao; Jiang, Guoping; Zheng, Shusen; Zhou, Lin

    2014-01-01

    Background Although liver transplantation is one of the most efficient curative therapies of end stage liver diseases, recipients may suffer liver graft loss opst-operation. IRF-5, a member of Interferon Regulatory Factors, functions as a key regulator in TLR4 cascade, and is capable of inducing inflammatory cytokines. Although TLR4 has been proved to contribute to acute allograft rejection, including after liver transplantation, the correlation between IRF5 gene and acute rejection has not been elucidated yet. Methods The study enrolled a total of 289 recipients, including 39 females and 250 males, and 39 recipients developed acute allograft rejection within 6 months post-transplantation. The allograft rejections were diagnosed by liver biopsies. Genome DNA of recipients was extracted from pre-operative peripheral blood. Genotyping of IRF-5, including rs3757385, rs752637 and rs11761199, was performed, followed by SNP frequency and Hardy-Weinberg equilibrium analysis. Results The genetic polymorphism of rs3757385 was found associated with acute rejection. G/G homozygous individuals were at higher risk of acute rejection, with a P value of 0.042 (OR = 2.34 (1.07–5.10)). Conclusions IRF5, which transcriptionally activates inflammatory cytokines, is genetically associated with acute rejection and might function as a risk factor for acute rejection of liver transplantations. PMID:24788560

  15. A novel robust disturbance rejection anti-windup framework

    NASA Astrophysics Data System (ADS)

    Li, Guang; Herrmann, Guido; Stoten, David P.; Tu, Jiaying; Turner, Matthew C.

    2011-01-01

    In this article, we propose a novel anti-windup (AW) framework for coping with input saturation in the disturbance rejection problem of stable plant systems. This framework is based on the one developed by Weston and Postlethwaite (W&P) (Weston, P.F., and Postlethwaite, I. (2000), 'Linear Conditioning for Systems Containing Saturating Actuators', Automatica, 36, 1347-1354). The new AW-design improves the disturbance rejection performance over the design framework usually suggested for the coprime-factorisation based W&P-approach. Performance improvement is achieved by explicitly incorporating a transfer function, which represents the effect of the disturbance on the nonlinear loop, into the AW compensator synthesis. An extra degree of freedom is exploited for the coprime factorisation, resulting in an implicitly computed multivariable algebraic loop for the AW-implementation. Suggestions are made to overcome the algebraic loop problem via explicit computation. Furthermore, paralleling the results of former work (Turner, M.C., Herrmann, G., and Postlethwaite, I. (2007), 'Incorporating Robustness Requirements into Antiwindup Design', IEEE Transactions on Automatic Control, 52, 1842-1855), the additive plant uncertainty is incorporated into the AW compensator synthesis, by using a novel augmentation for the disturbance rejection problem. In this new framework, it is shown that the internal model control (IMC) scheme is optimally robust, as was the case in Turner, Herrmann, and Postlethwaite (2007) and Zheng and Morari (Zheng, A., and Morari, M. (1994), 'Anti-windup using Internal Model Control', International Journal of Control, 60, 1015-1024). The new AW approach is applied to the control of dynamically substructured systems (DSS) subject to external excitation signals and actuator limits. The benefit of this approach is demonstrated in the simulations for a small-scale building mass damper DSS and a quasi-motorcycle DSS.

  16. Changes in Self-Definition Impede Recovery From Rejection.

    PubMed

    Howe, Lauren C; Dweck, Carol S

    2016-01-01

    Previous research highlights how adept people are at emotional recovery after rejection, but less research has examined factors that can prevent full recovery. In five studies, we investigate how changing one's self-definition in response to rejection causes more lasting damage. We demonstrate that people who endorse an entity theory of personality (i.e., personality cannot be changed) report alterations in their self-definitions when reflecting on past rejections (Studies 1, 2, and 3) or imagining novel rejection experiences (Studies 4 and 5). Further, these changes in self-definition hinder post-rejection recovery, causing individuals to feel haunted by their past, that is, to fear the recurrence of rejection and to experience lingering negative affect from the rejection. Thus, beliefs that prompt people to tie experiences of rejection to self-definition cause rejection's impact to linger. © 2015 by the Society for Personality and Social Psychology, Inc.

  17. Lung allograft rejection in the rat. V. Inhaled stimuli aggravate the rejection response

    SciTech Connect

    Prop, J.; Jansen, H.M.; Wildevuur, C.R.; Nieuwenhuis, P.

    1985-07-01

    Responses to inhaled stimuli in lung allografts might intensify the rejection response against the grafts. Therefore, the authors investigated the rejection of lung allografts in rats exposed to various degrees of stimuli via the airways. A group of these rats was selectively decontaminated to eliminate infection of the graft. Stimuli provided were intrabronchially injected purified protein derivative in sensitized rats and dust inhaled from sawdust used as bedding in the cages. Both intrabronchially injected purified protein derivative and stimuli inhaled from sawdust were found to aggravate lung allograft rejection, thus shortening mean graft survival from 32 to 11 days. Selective decontamination did prolong lung graft survival (p less than 0.05) because it lowered the overall immune reactivity of the recipient rats. For clinical lung transplantation, these observations suggest that patients should be selectively decontaminated and protected against inhalation of exogenous stimuli during a rejection episode.

  18. To Accept or Reject? The Impact of Adolescent Rejection Sensitivity on Early Adult Romantic Relationships

    PubMed Central

    Hafen, Christopher A.; Spilker, Ann; Chango, Joanna; Marston, Emily S.; Allen, Joseph P.

    2013-01-01

    Successfully navigating entry into romantic relationships is a key task in adolescence, which sensitivity to rejection can make difficult to accomplish. This study uses multi-informant data from a community sample of 180 adolescents assessed repeatedly from age 16 to 22. Individuals with elevated levels of rejection sensitivity at age 16 were less likely to have a romantic partner at age 22, reported more anxiety and avoidance when they did have relationships, and were observed to be more negative in their interactions with romantic partners. In addition, females whose rejection sensitivity increased during late adolescence were more likely to adopt a submissive pattern within adult romantic relationships, further suggesting a pattern in which rejection sensitivity forecasts difficulties. PMID:24729668

  19. Background investigation in EDELWEISS-III

    SciTech Connect

    Scorza, Silvia

    2015-08-17

    Protection from and rejection of backgrounds is a key issue for the EDELWEISS-III direct dark matter detection experiment which aims at exploring the 10{sup −9} pb cross-section region for spin-independent WIMP-nucleon interaction. The detector is located in the low radioactivity environment of the Modane Underground Laboratory and consists of 36 advanced FID germanium detectors operating at 18 mK in a dilution refrigerator in order to identify eventual rare nuclear recoils induced by elastic scattering of WIMPs from our Galactic halo. I will discuss the background and the methods of rejecting it with the FID detectors. Detector performances and the first analysis of data acquired in a long-term campaign will be presented as well. The FID detector technology is not limited to EDELWEISS-III but can further be employed in the next generation of cryogenic detector experiments.

  20. Heat Rejection Concepts for Lunar Fission Surface Power Applications

    NASA Technical Reports Server (NTRS)

    Siamidis, John

    2006-01-01

    This paper describes potential heat rejection design concepts for lunar surface Brayton power conversion systems. Brayton conversion systems are currently under study by NASA for surface power applications. Surface reactors may be used for the moon to power human outposts enabling extended stays and closed loop life support. The Brayton Heat Rejection System (HRS) must dissipate waste heat generated by the power conversion system due to inefficiencies in the thermal-to-electric conversion process. Space Brayton conversion system designs tend to optimize at efficiencies of about 20 to 25 percent with radiator temperatures in the 400 K to 600 K range. A notional HRS was developed for a 100 kWe-class Brayton power system that uses a pumped water heat transport loop coupled to a water heat pipe radiator. The radiator panels employ a tube and fin construction consisting of regularly-spaced circular heat pipes contained within two composite facesheets. The water heat pipes interface to the coolant through curved sections partially contained within the cooling loop. The paper evaluates various design parameters including radiator panel orientation, coolant flow path, and facesheet thickness. Parameters were varied to compare design options on the basis of H2O pump pressure rise and required power, heat pipe unit power and radial flux, radiator area, radiator panel areal mass, and overall HRS mass.

  1. Heat Rejection Concepts for Brayton Power Conversion Systems

    NASA Technical Reports Server (NTRS)

    Siamidis, John; Mason, Lee; Beach, Duane; Yuko, James

    2005-01-01

    This paper describes potential heat rejection design concepts for closed Brayton cycle (CBC) power conversion systems. Brayton conversion systems are currently under study by NASA for Nuclear Electric Propulsion (NEP) applications. The Heat Rejection Subsystem (HRS) must dissipate waste heat generated by the power conversion system due to inefficiencies in the thermal-to-electric conversion process. Space Brayton conversion system designs tend to optimize at efficiencies of about 20 to 25 percent with radiator temperatures in the 400 to 600 K range. A notional HRS was developed for a 100 kWe-class Brayton power system that uses a pumped sodium-potassium (NaK) heat transport loop coupled to a water heat pipe radiator. The radiator panels employ a sandwich construction consisting of regularly-spaced circular heat pipes contained within two composite facesheets. Heat transfer from the NaK fluid to the heat pipes is accomplished by inserting the evaporator sections into the NaK duct channel. The paper evaluates various design parameters including heat pipe diameter, heat pipe spacing, and facesheet thickness. Parameters were varied to compare design options on the basis of NaK pump pressure rise and required power, heat pipe unit power and radial flux, radiator panel areal mass, and overall HRS mass.

  2. Avian brood parasitism: information use and variation in egg-rejection behavior.

    PubMed

    Svennungsen, Thomas Owens; Holen, Øistein Haugsten

    2010-05-01

    Hosts of avian brood parasites often vary in their response to parasitized clutches: they may eject one or several eggs, desert the nest, or accept all the eggs. Focusing on hosts exposed to single-egg parasitism by an evicting brood parasite, we construct an optimality model that includes all these behavioral options and use it to explore variation in rejection behavior. We particularly consider the influence of egg mimicry and external cues (observations of adult parasites near the nest) on optimal choice of rejection behavior. We find that several rejection responses will be present in a host population under a wide range of conditions. Ejection of multiple eggs tends to be adaptive when egg mimicry is fairly accurate, external cues provide reliable information of the risk of parasitism, and the expected success of renesting is low. If the perceived risk of parasitism is high, ejection of one or a few eggs may be the optimal rejection response even in cases in which hosts cannot discriminate between eggs. This may have consequences for the long-term outcome of the coevolutionary chase between hosts and parasites. We propose an alternative evolutionary pathway by which egg ejection may first arise as a defense against brood parasitism.

  3. Prevalence of clinical rejection after surveillance biopsies in pediatric renal transplants: does early subclinical rejection predispose to subsequent rejection episodes?

    PubMed

    Hymes, Leonard C; Warshaw, Barry L; Hennigar, Randolph A; Amaral, Sandra G; Greenbaum, Larry A

    2009-11-01

    We analyzed rates of both SCR and CR in children receiving SB at three months post-transplant to determine if SCR predisposed patients to acute CR. Acute rejection was defined according to Banff criteria to include borderline classification or higher. All cases of SCR and CR were treated with anti-rejection protocols. Between October 2004 and July 2008, 89 SB were performed at three months post-transplant. Twenty-six cases of SCR were detected (29%). Sixteen patients experienced 22 episodes of biopsy-proven CR occurring after SB, including seven episodes following SCR and 15 after normal SB. The onset of CR varied from one to 27 months after SB and occurred at similar intervals for cases with SCR and normal SB. The percentage of patients remaining free of CR at 30 months post-transplant was similar in patients with SCR and normal SB. Renal function and graft survival at 30 months also were no different between patients with SCR and those with normal SB. Early-SCR, when treated with rejection protocols, is not a prognostic indicator for subsequent CR episodes.

  4. Rejection sensitivity moderates the impact of rejection on self-concept clarity.

    PubMed

    Ayduk, Ozlem; Gyurak, Anett; Luerssen, Anna

    2009-11-01

    Self-concept clarity (SCC) refers to the extent to which self-knowledge is clearly and confidently defined, internally consistent, and temporally stable. Research shows that SCC can be undermined by failures in valued goal domains. Because preventing rejection is an important self-relevant goal for people high in rejection sensitivity (RS), it is hypothesized here that failures to attain this goal would cause them to experience diminished SCC. Study 1, an experimental study, showed that high-RS people's SCC was undermined following rejection but not following an aversive experience unrelated to rejection. Study 2, a daily diary study of couples in relationships, used occurrence of partner conflicts to operationalize rejection. Replicating the findings in Study 1, having a conflict on any given diary day predicted a greater reduction in the SCC of high- compared to low-RS people on the following day. The implications for understanding the conditions under which rejection negatively affects the self-concept are discussed.

  5. Rejection Sensitivity Moderates the Impact of Rejection on Self-Concept Clarity

    PubMed Central

    Ayduk, Özlem; Gyurak, Anett; Luerssen, Anna

    2014-01-01

    Self-concept clarity (SCC) refers to the extent to which self-knowledge is clearly and confidently defined, internally consistent, and temporally stable. Research shows that SCC can be undermined by failures in valued goal domains. Because preventing rejection is an important self-relevant goal for people high in rejection sensitivity (RS), it is hypothesized here that failures to attain this goal would cause them to experience diminished SCC. Study 1, an experimental study, showed that high-RS people’s SCC was undermined following rejection but not following an aversive experience unrelated to rejection. Study 2, a daily diary study of couples in relationships, used occurrence of partner conflicts to operationalize rejection. Replicating the findings in Study 1, having a conflict on any given diary day predicted a greater reduction in the SCC of high- compared to low-RS people on the following day. The implications for understanding the conditions under which rejection negatively affects the self-concept are discussed. PMID:19713567

  6. Parallel Batch Scheduling of Deteriorating Jobs with Release Dates and Rejection

    PubMed Central

    Zou, Juan; Miao, Cuixia

    2014-01-01

    We consider the unbounded parallel batch scheduling with deterioration, release dates, and rejection. Each job is either accepted and processed on a single batching machine, or rejected by paying penalties. The processing time of a job is a simple linear increasing function of its starting time. The objective is to minimize the sum of the makespan of the accepted jobs and the total penalty of the rejected jobs. First, we show that the problem is NP-hard in the ordinary sense. Then, we present two pseudopolynomial time algorithms and a fully polynomial-time approximation scheme to solve this problem. Furthermore, we provide an optimal O(nlog⁡n) time algorithm for the case where jobs have identical release dates. PMID:25143969

  7. Children reject inequity out of spite.

    PubMed

    McAuliffe, Katherine; Blake, Peter R; Warneken, Felix

    2014-12-01

    When confronted with inequality, human children and adults sacrifice personal gain to reduce the pay-offs of other individuals, exhibiting apparently spiteful motivations. By contrast, sacrifice of personal gain by non-human animals is often interpreted as frustration. Spite may thus be a uniquely human motivator. However, to date, no empirical study has demonstrated that psychological spite actually drives human behaviour, leaving the motivation for inequity aversion unclear. Here, we ask whether 4- to 9-year-old children and adults reject disadvantageous inequity (less for self, more for peer) out of spite or frustration. We show that children, but not adults, are more likely to reject disadvantageous allocations when doing so deprives their peer of a better reward (spite) than when their peer has already received the better reward (frustration). Spiteful motivations are thus present early in childhood and may be a species-specific component of humans' developing cooperative and competitive behaviour.

  8. A new rejection of moral expertise.

    PubMed

    Cowley, Christopher

    2005-01-01

    There seem to be two clearly-defined camps in the debate over the problem of moral expertise. On the one hand are the "Professionals", who reject the possibility entirely, usually because of the intractable diversity of ethical beliefs. On the other hand are the "Ethicists", who criticise the Professionals for merely stipulating science as the most appropriate paradigm for discussions of expertise. While the subject matter and methodology of good ethical thinking is certainly different from that of good clinical thinking, they argue, this is no reason for rejecting the possibility of a distinctive kind of expertise in ethics, usually based on the idea of good justification. I want to argue that both are incorrect, partly because of the reasons given by one group against the other, but more importantly because both neglect what is most distinctive about ethics: that it is personal in a very specific way, without collapsing into relativism.

  9. Mechanisms of allograft rejection of corneal endothelium

    SciTech Connect

    Tagawa, Y.; Silverstein, A.M.; Prendergast, R.A.

    1982-07-01

    The local intraocular graft-vs.-host (GVH) reaction, involving the destruction of the corneal endothelial cells of the rabbit host by sensitized donor lymphoid cells, has been used to study the mechanism of corneal allograft rejection. Pretreatment of donor cells with a specific mouse monoclonal hybridoma anti-T cell antibody and complement suppresses the destructive reaction, suggesting that a cellular-immune mechanism is primarily involved. Pretreatment of donor cells with mitomycin-C completely abolishes the local GVH reaction, indicating that the effector lymphocytes must undergo mitosis within the eye before they can engage in target cell destruction. Finally, studies of the local GVH reaction in irradiated leukopenic recipients or in preinflamed rabbit eyes suggest that host leukocytes may contribute nonspecifically to enhance the destructive process. These studies show that the local ocular GVH reaction may provide a useful model for the study of the mechanisms involved in the rejection of corneal allografts.

  10. Allorecognition by T Lymphocytes and Allograft Rejection

    PubMed Central

    Marino, Jose; Paster, Joshua; Benichou, Gilles

    2016-01-01

    Recognition of donor antigens by recipient T cells in secondary lymphoid organs initiates the adaptive inflammatory immune response leading to the rejection of allogeneic transplants. Allospecific T cells become activated through interaction of their T cell receptors with intact allogeneic major histocompatibility complex (MHC) molecules on donor cells (direct pathway) and/or donor peptides presented by self-MHC molecules on recipient antigen-presenting cells (APCs) (indirect pathway). In addition, recent studies show that alloreactive T cells can also be stimulated through recognition of allogeneic MHC molecules displayed on recipient APCs (MHC cross-dressing) after their transfer via cell–cell contact or through extracellular vesicles (semi-direct pathway). The specific allorecognition pathway used by T cells is dictated by intrinsic and extrinsic factors to the allograft and can influence the nature and magnitude of the alloresponse and rejection process. Consequently, various organs and tissues such as skin, cornea, and solid organ transplants are recognized differently by pro-inflammatory T cells through these distinct pathways, which may explain why these grafts are rejected in a different fashion. On the other hand, the mechanisms by which anti-inflammatory regulatory T cells (Tregs) recognize alloantigen and promote transplantation tolerance are still unclear. It is likely that thymic Tregs are activated through indirect allorecognition, while peripheral Tregs recognize alloantigens in a direct fashion. As we gain insights into the mechanisms underlying allorecognition by pro-inflammatory and Treg cells, novel strategies are being designed to prevent allograft rejection in the absence of ongoing immunosuppressive drug treatment in patients. PMID:28018349

  11. The Role of Conspiracist Ideation and Worldviews in Predicting Rejection of Science

    PubMed Central

    Lewandowsky, Stephan; Gignac, Gilles E.; Oberauer, Klaus

    2013-01-01

    Background Among American Conservatives, but not Liberals, trust in science has been declining since the 1970's. Climate science has become particularly polarized, with Conservatives being more likely than Liberals to reject the notion that greenhouse gas emissions are warming the globe. Conversely, opposition to genetically-modified (GM) foods and vaccinations is often ascribed to the political Left although reliable data are lacking. There are also growing indications that rejection of science is suffused by conspiracist ideation, that is the general tendency to endorse conspiracy theories including the specific beliefs that inconvenient scientific findings constitute a “hoax.” Methodology/Principal findings We conducted a propensity weighted internet-panel survey of the U.S. population and show that conservatism and free-market worldview strongly predict rejection of climate science, in contrast to their weaker and opposing effects on acceptance of vaccinations. The two worldview variables do not predict opposition to GM. Conspiracist ideation, by contrast, predicts rejection of all three scientific propositions, albeit to greatly varying extents. Greater endorsement of a diverse set of conspiracy theories predicts opposition to GM foods, vaccinations, and climate science. Conclusions Free-market worldviews are an important predictor of the rejection of scientific findings that have potential regulatory implications, such as climate science, but not necessarily of other scientific issues. Conspiracist ideation, by contrast, is associated with the rejection of all scientific propositions tested. We highlight the manifold cognitive reasons why conspiracist ideation would stand in opposition to the scientific method. The involvement of conspiracist ideation in the rejection of science has implications for science communicators. PMID:24098391

  12. Absence of Intragraft B Cells in Rejection Biopsies After Rituximab Induction Therapy: Consequences for Clinical Outcome

    PubMed Central

    van den Hoogen, Martijn W.F.; Steenbergen, Eric J.; Baas, Marije C.; Florquin, Sandrine; Hilbrands, Luuk B.

    2017-01-01

    Background The pathophysiological role of intragraft B cells during renal allograft rejection is unclear. Methods We studied B-cell infiltration during acute rejection in 53 patients who participated in a clinical trial in which adult renal transplant patients were randomized between a single intraoperative dose of rituximab (375 mg/m2) or placebo as induction therapy. Two independent pathologists scored all biopsies in a blinded fashion according to the Banff classification and scored for the presence of B cells and plasma cells using CD79a and CD138 as markers. Results The majority of acute rejections were T cell–mediated. The proportion of acute rejections with an antibody-mediated component tended to be lower in rituximab-treated patients (4/23, 17.4%) than in placebo-treated patients (11/30, 36.7%; P = 0.14). Biopsies of rituximab-treated patients had significantly lower scores for B cells (0.00; range, 0.00-0.50 vs 1.70; range, 0.60-3.30; P < 0.0001) and plasma cells (0.10; range, 0.00-1.90 vs 0.40; range, 0.00-7.50; P = 0.006). During acute rejection, intragraft clusters of B cells were not observed after rituximab induction therapy. However, the depletion of intragraft B cells during acute rejection did not affect steroid resistance, proteinuria, graft function at 2 years follow-up, or patient and graft survival at a median follow-up of 4.1 years (range, 2.0-6.2 years). Conclusions These data do not support a harmful influence of intragraft B cells present during acute allograft rejection on the clinical course within the first few years after renal transplantation. PMID:28405599

  13. MONITORING WASTE HEAT REJECTION TO THE ENVIRONMENT VIA REMOTE SENSING

    SciTech Connect

    Garrett, A

    2009-01-13

    Nuclear power plants typically use waste heat rejection systems such as cooling lakes and natural draft cooling towers. These systems are designed to reduce cooling water temperatures sufficiently to allow full power operation even during adverse meteorological conditions. After the power plant is operational, the performance of the cooling system is assessed. These assessments usually rely on measured temperatures of the cooling water after it has lost heat to the environment and is being pumped back into the power plant (cooling water inlet temperature). If the cooling system performance is not perceived to be optimal, the utility will collect additional data to determine why. This paper discusses the use of thermal imagery collected from aircraft and satellites combined with numerical simulation to better understand the dynamics and thermodynamics of nuclear power plant waste heat dissipation systems. The ANS meeting presentation will discuss analyses of several power plant cooling systems based on a combination of remote sensing data and hydrodynamic modeling.

  14. 43 CFR 3141.6-6 - Rejection of bid.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LEASING IN SPECIAL TAR SAND AREAS Leasing in Special Tar Sand Areas § 3141.6-6 Rejection of bid. If the high bid is rejected for failure by the successful...

  15. 43 CFR 3141.6-6 - Rejection of bid.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LEASING IN SPECIAL TAR SAND AREAS Leasing in Special Tar Sand Areas § 3141.6-6 Rejection of bid. If the high bid is rejected for failure by the successful...

  16. 43 CFR 3141.6-6 - Rejection of bid.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LEASING IN SPECIAL TAR SAND AREAS Leasing in Special Tar Sand Areas § 3141.6-6 Rejection of bid. If the high bid is rejected for failure by the successful...

  17. 43 CFR 3141.6-6 - Rejection of bid.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LEASING IN SPECIAL TAR SAND AREAS Leasing in Special Tar Sand Areas § 3141.6-6 Rejection of bid. If the high bid is rejected for failure by the successful...

  18. Active disturbance rejection controller for chemical reactor

    SciTech Connect

    Both, Roxana; Dulf, Eva H.; Muresan, Cristina I.

    2015-03-10

    In the petrochemical industry, the synthesis of 2 ethyl-hexanol-oxo-alcohols (plasticizers alcohol) is of high importance, being achieved through hydrogenation of 2 ethyl-hexenal inside catalytic trickle bed three-phase reactors. For this type of processes the use of advanced control strategies is suitable due to their nonlinear behavior and extreme sensitivity to load changes and other disturbances. Due to the complexity of the mathematical model an approach was to use a simple linear model of the process in combination with an advanced control algorithm which takes into account the model uncertainties, the disturbances and command signal limitations like robust control. However the resulting controller is complex, involving cost effective hardware. This paper proposes a simple integer-order control scheme using a linear model of the process, based on active disturbance rejection method. By treating the model dynamics as a common disturbance and actively rejecting it, active disturbance rejection control (ADRC) can achieve the desired response. Simulation results are provided to demonstrate the effectiveness of the proposed method.

  19. Challenges inherent to the diagnosis of antibody-mediated rejection in lung transplantation

    PubMed Central

    Chin, Nicholas; Westall, Glen; Paraskeva, Miranda; Ciciulla, John; Cantwell, Linda; Snell, Greg

    2015-01-01

    A bilateral sequential lung transplant was performed on a young female with cystic fibrosis-related bronchiectasis. She had negative prospective T- and B-cell crossmatch, and no known donor-specific antibodies. Post-transplantation, she developed bilateral pulmonary infiltrates of uncertain etiology, compounded by persistent tachycardia and questionable medication adherence. Despite aggressive intervention for suspected cellular rejection with high-dose intravenous corticosteroid, immunoglobulin, and anti-thymocyte globulin, her condition deteriorated to ultimately require ventilatory support. The eventual discovery of eplet donor-recipient mismatches on related DQB1 alleles raised the diagnosis of antibody-mediated rejection. Before plasmapheresis could be instituted, the patient rapidly succumbed to respiratory failure. Postmortem examination confirmed features of atypical allograft rejection, without evidence of classic acute cellular rejection. This is an unconventional case of antibody-mediated lung allograft rejection – an entity that is currently a difficult diagnostic and therapeutic challenge. Prevention of donor-specific antibodies by correct donor-recipient matching, and optimizing adherence post-transplantation are most important. PMID:25802749

  20. Ocular and cardiac artifact rejection for real-time analysis in MEG.

    PubMed

    Breuer, Lukas; Dammers, Jürgen; Roberts, Timothy P L; Shah, N Jon

    2014-08-15

    Recently, magnetoencephalography (MEG) based real-time brain computing interfaces (BCI) have been developed to enable novel and promising methods for neuroscience research. It is well known that artifact rejection prior to source localization largely enhances the localization accuracy. However, many BCI approaches neglect real-time artifact removal due to its time consuming process. The method (referred to as ocular and cardiac artifact rejection for real-time analysis, OCARTA) is based on constrained independent component analysis (cICA), where a priori information of the underlying source signals is used to optimize and accelerate signal decomposition. Thereby, prior information is incorporated by using the subject's individual cardiac and ocular activity. The algorithm automatically uses different separation strategies depending on the underlying source activity. OCARTA was tested and applied to data from three different but most commonly used MEG systems (4D-Neuroimaging, VSM MedTech Inc. and Elekta Neuromag). Ocular and cardiac artifacts were effectively reduced within one iteration at a time delay of 1ms performed on a standard PC (Intel Core i5-2410M). The artifact rejection results achieved with OCARTA are in line with the results reported for offline ICA-based artifact rejection methods. Due to the fast and subject-specific signal decomposition the new approach introduced here is capable of real-time ocular and cardiac artifact rejection. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Rejection of Electronic Recoils with the DMTPC Dark Matter Search

    NASA Astrophysics Data System (ADS)

    Lopez, J. P.; Ahlen, S.; Battat, J.; Caldwell, T.; Chernicoff, M.; Deaconu, C.; Dujmic, D.; Dushkin, A.; Fedus, W.; Fisher, P.; Golub, F.; Henderson, S.; Inglis, A.; Kaboth, A.; Kohse, G.; Kirsch, L.; Lanza, R.; Lee, A.; Monroe, J.; Ouyang, H.; Sahin, T.; Sciolla, G.; Skvorodnev, N.; Tomita, H.; Wellenstein, H.; Wolfe, I.; Yamamoto, R.; Yegoryan, H.

    The Dark Matter Time Projection Chamber (DMTPC) collaboration is developing a low-pressure gas TPC for detecting WIMP-nucleon interactions. DMTPC detectors use optical readout with CCD cameras to search for the daily modulation of the directional signal of the dark matter wind. An analysis of several charge readout channels has been developed to obtain additional information about ionization events in the detector. In order to reach sensitivities required for the WIMP detection, the detector needs to minimize backgrounds from electron recoils. This article shows that by using the readout of charge signals in addition to CCD readout, a preliminary statistics-limited 90% C.L. upper limit on the γ and e- rejection factor of 5.6 × 10-6 is obtained for energies between 40 keVee and 200 keVee.

  2. Delay discounting, risk-taking, and rejection sensitivity among individuals with Internet and Video Gaming Disorders

    PubMed Central

    Weinstein, Aviv; Abu, Hodaya Ben; Timor, Ayelet; Mama, Yaniv

    2016-01-01

    Background and aims There is a previous evidence for impulsivity in individuals with Internet and Video Gaming Disorders. The aim of this study was to examine whether Internet and video game addictions are associated with experiential delay discounting, risk-taking, and sensitivity to social rejection using computerized tasks and questionnaires. Methods Twenty participants (mean age 24, SD = 1.55) with high score on the Problematic Online Gaming Questionnaire (POGQ) were compared with 20 participants (mean age 24.8, SD = 1.34) with low score on the POGQ. They performed on computerized Balloon Analog Risk Task and Experiential Delay discounting Task (EDT), and filled in the sensitivity to social rejection questionnaire. Results Participants with high POGQ scores had lower measures of delay discounting, higher measures of risk-taking, and higher measures of sensitivity to social rejection compared with participants with low POGQ scores. Discussion The results of this study support the previous evidence of risk-taking and provide new evidence for difficulties in delay discounting and sensitivity to social rejection among those who score high on Internet and video games. Conclusions The results suggest that Internet- and video game-addicted individuals seek immediate gratification and cannot wait for later reward. Furthermore, these individuals spend time in the virtual world, where they feel safe, and avoid social interactions presumably due to fears of social rejection. PMID:27958761

  3. Corneal graft rejection occurs despite Fas ligand expression and apoptosis of infiltrating cells

    PubMed Central

    Williams, K A; Standfield, S D; Smith, J R; Coster, D J

    2005-01-01

    Background/aims: Constitutive expression of Fas ligand (CD95L) protects the eye against cell mediated immune responses by inducing apoptosis in infiltrating Fas bearing T cells. This study was designed to examine Fas ligand expression on acutely rejecting rat corneal grafts and to investigate the kinetics of induction of apoptosis in infiltrating leucocytes. Methods: Orthotopic penetrating corneal transplantation was performed between genetically disparate inbred rats. Fas ligand expression and the phenotype of infiltrating leucocytes were examined by immunohistochemistry. Apoptotic nuclei were visualised in sections of normal rat cornea, rejecting allografts, and time matched isografts by terminal deoxynucleotidyl transferase mediated dUTP biotin nick end labelling (TUNEL) and quantified by video image analysis. Staining with Hoechst dye 33258 was used to confirm the presence of apoptotic nuclei. Results: Fas ligand was expressed on corneal endothelial and epithelial cells during acute corneal graft rejection. At all time points examined, including as early as the fifth postoperative day, the cells infiltrating both corneal isografts and allografts were TUNEL positive. By the 15th postoperative day, over 90% of all nuclei, many of which were T cells, were apoptotic. Conclusion: Expression of Fas ligand is not downregulated on the cornea during allograft rejection and infiltrating leucocytes in both isografts and allografts die rapidly in situ. Despite the death of the cells believed to be responsible for rejection, isografts survive indefinitely whereas allografts are irreparably damaged. PMID:15834099

  4. Delay discounting, risk-taking, and rejection sensitivity among individuals with Internet and Video Gaming Disorders.

    PubMed

    Weinstein, Aviv; Abu, Hodaya Ben; Timor, Ayelet; Mama, Yaniv

    2016-12-01

    Background and aims There is a previous evidence for impulsivity in individuals with Internet and Video Gaming Disorders. The aim of this study was to examine whether Internet and video game addictions are associated with experiential delay discounting, risk-taking, and sensitivity to social rejection using computerized tasks and questionnaires. Methods Twenty participants (mean age 24, SD = 1.55) with high score on the Problematic Online Gaming Questionnaire (POGQ) were compared with 20 participants (mean age 24.8, SD = 1.34) with low score on the POGQ. They performed on computerized Balloon Analog Risk Task and Experiential Delay discounting Task (EDT), and filled in the sensitivity to social rejection questionnaire. Results Participants with high POGQ scores had lower measures of delay discounting, higher measures of risk-taking, and higher measures of sensitivity to social rejection compared with participants with low POGQ scores. Discussion The results of this study support the previous evidence of risk-taking and provide new evidence for difficulties in delay discounting and sensitivity to social rejection among those who score high on Internet and video games. Conclusions The results suggest that Internet- and video game-addicted individuals seek immediate gratification and cannot wait for later reward. Furthermore, these individuals spend time in the virtual world, where they feel safe, and avoid social interactions presumably due to fears of social rejection.

  5. Paying To Belong: When Does Rejection Trigger Ingratiation?

    PubMed Central

    Romero-Canyas, Rainer; Downey, Geraldine; Reddy, Kavita S.; Rodriguez, Sylvia; Cavanaugh, Timothy J.; Pelayo, Rosemary

    2010-01-01

    Societies and social scientists have long held the belief that exclusion induces ingratiation and conformity, an idea in contradiction with robust empirical evidence linking rejection with hostility and aggression. The classic literatures on ingratiation and conformity help resolve this contradiction by identifying circumstances under which rejection may trigger efforts to ingratiate. Jointly, findings from these literatures suggest that when people are given an opportunity to impress their rejecters, ingratiation is likely after rejection experiences that are harsh and that occur in important situations that threaten the individual’s self-definition. Four studies tested the hypothesis that people high in rejection sensitivity, and therefore dispositionally concerned about rejection, will utilize opportunities to ingratiate after harsh rejection in situations that are self-defining. In three studies of situations that are particularly self-defining for men, rejection predicted ingratiation among men (but not women) who were high in rejection sensitivity. In a fourth study, harsh rejection in a situation particularly self-defining for women predicted ingratiation among highly rejection-sensitive women (but not men). These findings help identify the specific circumstances under which people are willing to act in socially desirable ways toward those who have rejected them harshly. PMID:20649367

  6. When Is Peer Rejection Justifiable? Children's Understanding across Two Cultures

    ERIC Educational Resources Information Center

    Park, Yoonjung; Killen, Melanie

    2010-01-01

    This study investigated how Korean (N = 397) and U.S. (N = 333) children and adolescents (10 and 13 years of age) evaluated personality (aggression, shyness) and group (gender, nationality) characteristics as a basis for peer rejection in three contexts (friendship rejection, group exclusion, victimization). Overall, peer rejection based on…

  7. 28 CFR 540.13 - Notification of rejections.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CONTACT WITH PERSONS IN THE COMMUNITY Correspondence § 540.13 Notification of rejections. When correspondence is rejected, the Warden shall notify the sender in writing of the rejection and the reasons for... shall refer an appeal to an official other than the one who originally disapproved the...

  8. 28 CFR 540.13 - Notification of rejections.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CONTACT WITH PERSONS IN THE COMMUNITY Correspondence § 540.13 Notification of rejections. When correspondence is rejected, the Warden shall notify the sender in writing of the rejection and the reasons for... shall refer an appeal to an official other than the one who originally disapproved the...

  9. 28 CFR 540.13 - Notification of rejections.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CONTACT WITH PERSONS IN THE COMMUNITY Correspondence § 540.13 Notification of rejections. When correspondence is rejected, the Warden shall notify the sender in writing of the rejection and the reasons for... shall refer an appeal to an official other than the one who originally disapproved the...

  10. 28 CFR 540.13 - Notification of rejections.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CONTACT WITH PERSONS IN THE COMMUNITY Correspondence § 540.13 Notification of rejections. When correspondence is rejected, the Warden shall notify the sender in writing of the rejection and the reasons for... shall refer an appeal to an official other than the one who originally disapproved the...

  11. 28 CFR 540.13 - Notification of rejections.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CONTACT WITH PERSONS IN THE COMMUNITY Correspondence § 540.13 Notification of rejections. When correspondence is rejected, the Warden shall notify the sender in writing of the rejection and the reasons for... shall refer an appeal to an official other than the one who originally disapproved the...

  12. Parental Acceptance-Rejection Theory and the Phylogenetic Model.

    ERIC Educational Resources Information Center

    Rohner, Ronald P.

    Guided by specific theoretical and methodological points of view--the phylogenetic perspective and the universalistic approach respectively--this paper reports on a worldwide study of the antecedents and effects of parental acceptance and rejection. Parental acceptance-rejection theory postulates that rejected children throughout our species share…

  13. 19 CFR 191.41 - Rejected merchandise drawback.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Rejected merchandise drawback. 191.41 Section 191... THE TREASURY (CONTINUED) DRAWBACK Rejected Merchandise § 191.41 Rejected merchandise drawback. Section 313(c) of the Act, as amended (19 U.S.C. 1313(c)), provides for drawback upon the exportation or...

  14. Utility of sentinel flaps in assessing facial allograft rejection.

    PubMed

    Kueckelhaus, Maximilian; Fischer, Sebastian; Lian, Christine G; Bueno, Ericka M; Marty, Francisco M; Tullius, Stefan G; Pribaz, Julian J; Murphy, George J; Pomahac, Bohdan

    2015-01-01

    Skin biopsies are critical for histologic evaluation of rejection and proper treatment after facial allotransplantation. Many facial allografts provide only limited skin area, and frequent biopsies may also compromise aesthetic outcome. Sentinel flaps, recovered as free fasciocutaneous radial forearm flaps, have been used for remote-site rejection monitoring. They maintain their axial blood supply, similar to facial allografts. The correlation between facial allografts and sentinel flaps in cases of rejection is presented. The authors analyzed the experience of the Boston team's use of four sentinel flaps. Rejection was evaluated and results were compared for each time point. Sentinel flaps were used as functional flaps whenever possible. Results showed a reliable correlation between biopsy specimens taken from the facial allograft and sentinel flaps. During severe rejection episodes in 100 percent of biopsy pairs, both sites displayed a similar grade of rejection. In one case, clinical findings suggested rejection in the facial allograft but were unraveled as rosacea, because clinically there was no rejection displayed in the sentinel flap. The sentinel flap shows a reliable correlation to the facial allograft in cases of severe rejection, therefore providing a valuable tool for rejection monitoring in facial allotransplantation. Advantages of using these flaps include the avoidance of further surgical procedures to the primary vascularized composite allotransplant, additional use of the sentinel flap to repair damaged nonfacial sites, and its utility as both a clinical and histopathologic barometer of rejection and predictor of the potential existence of facial dermatitis unrelated to rejection. Therapeutic, IV.

  15. Cultural Rejection and Re-identification in Minority Group Members.

    ERIC Educational Resources Information Center

    Diller, Jerry V.

    There is little consistent research available on cultural rejection and re-identification in minority group members, but this report uses case study material to extrapolate three general factors precipitating rejection: self-hatred and negative chauvinism, quality of ethnic experience and rejection of religious experience. A four-step model for…

  16. Development of CDMS-II Surface Event Rejection Techniques and Their Extensions to Lower Energy Thresholds

    NASA Astrophysics Data System (ADS)

    Hofer, Thomas James

    2014-10-01

    The CDMS-II phase of the Cryogenic Dark Matter Search, a dark matter direct-detection experiment, was operated at the Soudan Underground Laboratory from 2003 to 2008. The full payload consisted of 30 ZIP detectors, totaling approximately 1.1 kg of Si and 4.8 kg of Ge, operated at temperatures of 50 mK. The ZIP detectors read out both ionization and phonon pulses from scatters within the crystals; channel segmentation and analysis of pulse timing parameters allowed effective fiducialization of the crystal volumes and background rejection sufficient to set world-leading limits at the times of their publications. A full re-analysis of the CDMS-II data was motivated by an improvement in the event reconstruction algorithms which improved the resolution of ionization energy and timing information. The Ge data were re-analyzed using three distinct background-rejection techniques; the Si data from runs 125--128 were analyzed for the first time using the most successful of the techniques from the Ge re-analysis. The results of these analyses prompted a novel "mid-threshold" analysis, wherein energy thresholds were lowered but background rejection using phonon timing information was still maintained. This technique proved to have significant discrimination power, maintaining adequate signal acceptance and minimizing background leakage. The primary background for CDMS-II analyses comes from surface events, whose poor ionization collection make them difficult to distinguish from true nuclear recoil events. The novel detector technology of SuperCDMS, the successor to CDMS-II, uses interleaved electrodes to achieve full ionization collection for events occurring at the top and bottom detector surfaces. This, along with dual-sided ionization and phonon instrumentation, allows for excellent fiducialization and relegates the surface-event rejection techniques of CDMS-II to a secondary level of background discrimination. Current and future SuperCDMS results hold great promise for

  17. Mechanisms involved in antibody- and complement-mediated allograft rejection

    PubMed Central

    2010-01-01

    Antibody-mediated rejection has become critical clinically because this form of rejection is usually unresponsive to conventional anti-rejection therapy, and therefore, it has been recognized as a major cause of allograft loss. Our group developed experimental animal models of vascularized organ transplantation to study pathogenesis of antibody- and complement-mediated endothelial cell injury leading to graft rejection. In this review, we discuss mechanisms of antibody-mediated graft rejection resulting from activation of complement by C1q- and MBL (mannose-binding lectin)-dependent pathways and interactions with a variety of effector cells, including macrophages and monocytes through Fcγ receptors and complement receptors. PMID:20135240

  18. States Must Reject National Education Standards while There Is Still Time. Backgrounder, No. 2680

    ERIC Educational Resources Information Center

    Burke, Lindsey M.

    2012-01-01

    For four and a half decades, the federal role in education has been growing. Costly in terms of taxpayer dollars spent and local control of education lost, this expanding federal control has failed to improve outcomes for America's children. National standards will further expand Washington's role--and will remove parents from decisions about the…

  19. Background Rejection of Charged Particles in the Simbol-X Telescope: Preliminary Study of Protons Scattering

    NASA Astrophysics Data System (ADS)

    Dell'Orto, E.; Barbera, M.; Bulgarelli, A.; Fioretti, V.; Malaguti, G.; Mineo, T.; Pareschi, G.; Rigato, V.; Spiga, D.; Tagliaferri, G.

    2009-05-01

    X-ray telescopes equipped with focusing optics in high eccentric orbit, as e.g. Newton-XMM and Chandra, showed a degradation of the detector performance and an important increase of the noise due to soft protons with energy between a few tens of keV and a few MeV, that are focused on the detector through the mirror module. It should be noted that the focusing of the protons by Wolter optics was an unexpected phenomenon. In Simbol-X a magnetic diverter will be implemented to deflect protons, in order to reduce the flux of charged particles impinging upon the focal plane. Obviously the design of the diverter should take into consideration the protons distribution at the exit of the mirror module; for this reason a detailed simulation about the interaction of particles with the mirror surface is necessary. Here we will present the scattering protons models currently under consideration, suggesting a preliminary solution for the design of the magnetic diverter. We will also discuss an ad hoc experiment to study this problem.

  20. Background Rejection of Charged Particles in the Simbol-X Telescope: Preliminary Study of Protons Scattering

    SciTech Connect

    Dell'Orto, E.; Barbera, M.; Bulgarelli, A.; Fioretti, V.; Malaguti, G.; Mineo, T.; Pareschi, G.; Spiga, D.; Tagliaferri, G.; Rigato, V.

    2009-05-11

    X-ray telescopes equipped with focusing optics in high eccentric orbit, as e.g. Newton-XMM and Chandra, showed a degradation of the detector performance and an important increase of the noise due to soft protons with energy between a few tens of keV and a few MeV, that are focused on the detector through the mirror module. It should be noted that the focusing of the protons by Wolter optics was an unexpected phenomenon. In Simbol-X a magnetic diverter will be implemented to deflect protons, in order to reduce the flux of charged particles impinging upon the focal plane. Obviously the design of the diverter should take into consideration the protons distribution at the exit of the mirror module; for this reason a detailed simulation about the interaction of particles with the mirror surface is necessary. Here we will present the scattering protons models currently under consideration, suggesting a preliminary solution for the design of the magnetic diverter. We will also discuss an ad hoc experiment to study this problem.

  1. Dispositional mindfulness and rejection sensitivity: The critical role of nonjudgment.

    PubMed

    Peters, Jessica R; Eisenlohr-Moul, Tory A; Smart, Laura M

    2016-04-01

    The pain of rejection is a crucial component of normal social functioning; however, heightened sensitivity to rejection can be impairing in numerous ways. Mindfulness-based interventions have been effective with several populations characterized by elevated sensitivity to rejection; however, the relationship between mindfulness and rejection sensitivity has been largely unstudied. The present study examines associations between rejection sensitivity and multiple dimensions of dispositional mindfulness, with the hypothesis that a nonjudgmental orientation to inner experiences would be both associated with decreased rejection sensitivity and attenuate the impact of sensitivity to rejection on general negative affect. A cross-sectional sample of undergraduates (n = 451) completed self-report measures of rejection sensitivity, dispositional mindfulness, and trait-level negative affect. Significant zero-order correlations and independent effects were observed between most facets of dispositional mindfulness and rejection sensitivity, with nonjudging demonstrating the largest effects. As predicted, rejection sensitivity was associated with negative affectivity for people low in nonjudging (β = .27, t = 5.12, p < .001) but not for people high in nonjudging (β = .06, t = .99, p = .324). These findings provide preliminary support for mindfulness, specifically the nonjudging dimension, as a protective factor against rejection sensitivity and its effects on affect.

  2. LATE ACUTE REJECTION IN LIVER TRANSPLANT: A SYSTEMATIC REVIEW

    PubMed Central

    NACIF, Lucas Souto; PINHEIRO, Rafael Soares; PÉCORA, Rafael Antônio de Arruda; DUCATTI, Liliana; ROCHA-SANTOS, Vinicius; ANDRAUS, Wellington; D'ALBUQUERQUE, Luiz Carneiro

    2015-01-01

    Introduction: Late acute rejection leads to worse patient and graft survival after liver transplantation. Aim: To analyze the reported results published in recent years by leading transplant centers in evaluating late acute rejection and update the clinical manifestations, diagnosis and treatment of liver transplantation. Method: Systematic literature review through Medline-PubMed database with headings related to late acute rejection in articles published until November 2013 was done. Were analyzed demographics, immunosuppression, rejection, infection and graft and patient survival rates. Results: Late acute rejection in liver transplantation showed poor results mainly regarding patient and graft survival. Almost all of these cohort studies were retrospective and descriptive. The incidence of late acute rejection varied from 7-40% in these studies. Late acute rejection was one cause for graft loss and resulted in different outcomes with worse patient and graft survival after liver transplant. Late acute rejection has been variably defined and may be a cause of chronic rejection with worse prognosis. Late acute rejection occurs during a period in which the goal is to maintain lower immunosuppression after liver transplantation. Conclusion: The current articles show the importance of late acute rejection. The real benefit is based on early diagnosis and adequate treatment at the onset until late follow up after liver transplantation. PMID:26537150

  3. Band reject filtration of the excitation spectrum at energy dispersive X-ray spectroscopy of weak signals

    NASA Astrophysics Data System (ADS)

    Tur'yanskii, A. G.; Gizha, S. S.; Senkov, V. M.; Pirshin, I. V.; Stanishevskii, Ya. M.

    2016-09-01

    The possibility of the efficient band reject filtration of the continuous X-ray excitation spectrum in the energy range E ≥ 8 keV is demonstrated. This makes it possible to strongly increase the sensitivity of energy dispersive X-ray spectroscopy at detecting of weak fluorescence lines. Spectral rejection is implemented by transmitting a primary beam through highly oriented pyrolytic graphite with given structural parameters. Diffraction extinction in pyrolytic graphite ensures the possibility of reducing the intensity by more than 20 dB and rejecting the spectral band with a width of 1 keV. The reduction of statistical fluctuations of the background of elastically scattered radiation is achieved when the bottom of the formed spectral valley is adjusted to the analyzed fluorescence line. The proposed scheme of band reject filtration also allows the suppression of intense characteristic lines in the primary and scattered radiation spectra.

  4. Mechanisms of solute rejection in solvent resistant nanofiltration: the effect of solvent on solute rejection.

    PubMed

    Darvishmanesh, Siavash; Degrève, Jan; Van der Bruggen, Bart

    2010-10-28

    The separation performance of solvent resistant nanofiltration (SRNF) membranes was studied in a systematic way to elucidate the complex mechanisms involved in rejection of solutes. Rejection of three dyes (Sudan II, Sudan Black, Sudan 408) from common organic solvents (methanol, ethanol, acetone, methyl ethyl ketone, toluene and n-hexane) through a polyimide based SRNF membrane, STARMEM™122, was studied. It was found that the rejection of the STARMEM™122 membrane was lower than that indicated by the manufacturer. The experimental observations for Sudan II were not promising for the rejection study as they were lower than expected. Sudan Black and Sudan 408, which are larger solutes than Sudan II, provided more interesting insights. The effects of the solvent on the membrane and solute were studied separately. A higher permeation rate of ketones and alcohols was observed, while permeabilities of non-polar solvents were low which shows that this membrane shows higher affinity toward semi-polar solvents (alcohols, ketones). The effect of the solvent on the solute's rejection, based on the results for Sudan Black and Sudan 408, was studied for solvents in the same chemical groups, since the membrane showed a similar separation performance for solvents with similar functional groups (e.g. alcohols). The effect of solvent on solute molecular size was investigated by using simulation with Molecular Dynamics. It was shown that the effective size of a molecule is dependent on the solvent due to solvation and hydration of the solute by the solvent. The size of the solute in the solvent belonging to a similar family was studied separately. It was clear that the rejection was influenced by molecular size of the solute in the same group of solvents. A surprising negative rejection of solutes was achieved for n-hexane. Although solutes in n-hexane have higher volume compared to those in other solvents, the affinity between the solute and membrane increases the solute

  5. Rejected asylum seekers: the problem of return.

    PubMed

    Noll, G

    1999-01-01

    "During this decade the return of rejected asylum seekers has become an issue of increasing concern to major asylum states in the industrialized world. This article exposes the various political and legal approaches taken by returning states as well as the constraints emerging from human rights law. As a rigid control paradigm and related enforcement practices entail a considerable risk of human rights violations, it seems reasonable to focus on measures enhancing the voluntary compliance of all actors involved with norms governing return." (EXCERPT)

  6. Confidence and rejection in automatic speech recognition

    NASA Astrophysics Data System (ADS)

    Colton, Larry Don

    Automatic speech recognition (ASR) is performed imperfectly by computers. For some designated part (e.g., word or phrase) of the ASR output, rejection is deciding (yes or no) whether it is correct, and confidence is the probability (0.0 to 1.0) of it being correct. This thesis presents new methods of rejecting errors and estimating confidence for telephone speech. These are also called word or utterance verification and can be used in wordspotting or voice-response systems. Open-set or out-of-vocabulary situations are a primary focus. Language models are not considered. In vocabulary-dependent rejection all words in the target vocabulary are known in advance and a strategy can be developed for confirming each word. A word-specific artificial neural network (ANN) is shown to discriminate well, and scores from such ANNs are shown on a closed-set recognition task to reorder the N-best hypothesis list (N=3) for improved recognition performance. Segment-based duration and perceptual linear prediction (PLP) features are shown to perform well for such ANNs. The majority of the thesis concerns vocabulary- and task-independent confidence and rejection based on phonetic word models. These can be computed for words even when no training examples of those words have been seen. New techniques are developed using phoneme ranks instead of probabilities in each frame. These are shown to perform as well as the best other methods examined despite the data reduction involved. Certain new weighted averaging schemes are studied but found to give no performance benefit. Hierarchical averaging is shown to improve performance significantly: frame scores combine to make segment (phoneme state) scores, which combine to make phoneme scores, which combine to make word scores. Use of intermediate syllable scores is shown to not affect performance. Normalizing frame scores by an average of the top probabilities in each frame is shown to improve performance significantly. Perplexity of the wrong

  7. Scatter rejection in multislit digital mammography

    SciTech Connect

    Aaslund, Magnus; Cederstroem, Bjoern; Lundqvist, Mats; Danielsson, Mats

    2006-04-15

    The scatter to primary ratio (SPR) was measured on a scanning multislit full-field digital mammography system for different thickness of breast equivalent material and different tube voltages. Scatter within the detector was measured separately and was found to be the major source of scatter in the assembly. Measured total SPRs below 6% are reported for breast range 3-7 cm. The performance of the multislit assembly is compared to other imaging geometries with different scatter rejection schemes by using the scatter detective quantum efficiency.

  8. What I see when I think it's about me: people low in rejection-sensitivity downplay cues of rejection in self-relevant interpersonal situations.

    PubMed

    Romero-Canyas, Rainer; Downey, Geraldine

    2013-02-01

    Gauging one's impression on a potential mate is challenging. There is a need to make reasonably accurate inferences from subtle, dynamic facial expressions and to maintain motivation to connect despite the risk of rejection. The interpersonal optimism of people low in rejection sensitivity (RS), people who confidently expect acceptance rather than anxiously expect rejection, as do their high RS counterparts, suggests that they may strategically underestimate social threat cues when inferring the impression they have made on others. To test this hypothesis, participants viewed the videotaped reactions of individuals said to have read the participant's own or someone else's biographical sketch in an online dating context, and then estimated the emotions of the targets. Estimates of negativity were unrelated to RS when participants believed the videos captured the reactions to someone else's biographical sketch. However, to the extent that participants were low in RS, they made lower estimates of negativity when they believed the videos showed reactions to their biographical sketch compared to when they believed the videos captured the reactions to someone else's biographical sketch. The tracking accuracy of participants estimating negativity was unrelated to RS under either condition, but increased with trait empathy. RS was unrelated to estimates of positivity. Supporting functional perspectives on interpersonal perception, results show that interpersonal optimism shapes impressions of others' reactions to the self in ways that can foster relationship initiation. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  9. Monte Carlo Simulations of Background Spectra in Integral Imager Detectors

    NASA Technical Reports Server (NTRS)

    Armstrong, T. W.; Colborn, B. L.; Dietz, K. L.; Ramsey, B. D.; Weisskopf, M. C.

    1998-01-01

    Predictions of the expected gamma-ray backgrounds in the ISGRI (CdTe) and PiCsIT (Csl) detectors on INTEGRAL due to cosmic-ray interactions and the diffuse gamma-ray background have been made using a coupled set of Monte Carlo radiation transport codes (HETC, FLUKA, EGS4, and MORSE) and a detailed, 3-D mass model of the spacecraft and detector assemblies. The simulations include both the prompt background component from induced hadronic and electromagnetic cascades and the delayed component due to emissions from induced radioactivity. Background spectra have been obtained with and without the use of active (BGO) shielding and charged particle rejection to evaluate the effectiveness of anticoincidence counting on background rejection.

  10. Monte Carlo Simulations of Background Spectra in Integral Imager Detectors

    NASA Technical Reports Server (NTRS)

    Armstrong, T. W.; Colborn, B. L.; Dietz, K. L.; Ramsey, B. D.; Weisskopf, M. C.

    1998-01-01

    Predictions of the expected gamma-ray backgrounds in the ISGRI (CdTe) and PiCsIT (Csl) detectors on INTEGRAL due to cosmic-ray interactions and the diffuse gamma-ray background have been made using a coupled set of Monte Carlo radiation transport codes (HETC, FLUKA, EGS4, and MORSE) and a detailed, 3-D mass model of the spacecraft and detector assemblies. The simulations include both the prompt background component from induced hadronic and electromagnetic cascades and the delayed component due to emissions from induced radioactivity. Background spectra have been obtained with and without the use of active (BGO) shielding and charged particle rejection to evaluate the effectiveness of anticoincidence counting on background rejection.

  11. Mechanisms of rejection: role of complement.

    PubMed

    Farrar, Conrad A; Sacks, Steven H

    2014-02-01

    To provide the reader with an up-to-date comprehensive review of recent findings that highlight advances describing how proteins of the complement cascades contribute to the pathogenesis of solid organ rejection. The review is focussed mainly on renal transplantation. Of note are recent advances in elucidating the interactions between anaphylatoxins and their receptors in organ transplantation; there is evidence of direct engagement of C5aR on donor tubules and in addition, mechanisms by which the allostimulatory capacity of dendritic cells is modulated by complement are more fully understood. Activation of the lectin pathway is increasingly implicated in allograft rejection and the role of complement in modulating regulatory T cells is being vigorously investigated. As an alternative to systemic complement inhibition, there is continued focus on the design of targeted anti-complement therapies, directed to the donor organ. Complement has evolved as the first line of defence against pathogens, employing well defined effector mechanisms to rapidly remove infectious material. However, complement effector mechanisms are also triggered during inflammation associated with solid organ transplantation. Hence, complement has a significant role in mediating donor organ injury during both the initial ischaemia/reperfusion phase and the subsequent adaptive immune responses. Research on mechanisms of complement-mediated injury in transplantation provide a basis for the development of therapies that are aimed at transiently blocking complement activation at the site of injury, whereas leaving systemic anti-bacterial complement effector mechanisms intact.

  12. The 'fine line' of heat rejection.

    PubMed

    Carruthers, Phillip

    2010-09-01

    Selection of heat rejection equipment has traditionally entailed a choice between the higher energy consumption of an air-cooled solution, and the high water consumption of a water-cooled solution. This paper examines advancement in heat rejection technology and the way it can be applied to air conditioning and refrigeration plant in healthcare and other facilities. It also examines field difficulties encountered in pipework design as the knowledge and experience levels of engineers designing systems with remote condensers diminish. With plant larger than 1,000 kW, the only option previously has been water-cooled solutions using an array of cooling towers, or perhaps an evaporative condenser, since air-cooled plant involved massive volumes of chemical refrigerant, which posed a problem ecologically. An additional hurdle was problems associated with limitations on pipe lengths for refrigeration plant. The advent of adiabatically pre-cooled closed circuit coolers and air-cooled condensers has introduced an alternative to cooling towers that offers the potential for "water-cooled performance" from an air-cooled solution with no serious threat of Legionella contamination. However, each application needs to be considered on a case-by-case basis. The paper examines, in detail, the impact of adiabatic pre-cooling, with recent examples of its application in sub-tropical Brisbane providing evidence of the potential performance achievable.

  13. Changing Paradigms in the Management of Rejection in Kidney Transplantation

    PubMed Central

    Maier, Mirela; Takano, Tomoko; Sapir-Pichhadze, Ruth

    2017-01-01

    Purpose of review: P4 medicine denotes an evolving field of medicine encompassing predictive, preventive, personalized, and participatory medicine. Using the example of kidney allograft rejection because of donor-recipient incompatibility in human leukocyte antigens, this review outlines P4 medicine’s relevance to the various stages of the kidney transplant cycle. Sources of information: A search for English articles was conducted in Medline via OvidSP (up to August 18, 2016) using a combination of subject headings (MeSH) and free text in titles, abstracts, and author keywords for the concepts kidney transplantation and P4 medicine. The electronic database search was expanded further on particular subject headings. Findings: Available histocompatibility methods exemplify current applications of the predictive and preventive domains of P4 medicine in kidney transplant recipients’ care. Pharmacogenomics are discussed as means to facilitate personalized immunosuppression regimens and promotion of active patient participation as a means to improve adherence. Limitations: For simplicity, this review focuses on rejection. P4 medicine, however, should more broadly address health concerns in kidney transplant recipients, including competing outcomes such as infections, malignancies, and cardiovascular disease. This review highlights how biomarkers to evaluate these competing outcomes warrant validation and standardization prior to their incorporation into clinical practice. Implications: Consideration of all 4 domains of the P4 medicine framework when caring for and/or studying kidney transplant recipients has the potential of increasing therapeutic efficiency, minimizing adverse effects, decreasing health care costs, and maximizing wellness. Technologies to gauge immune competency, immunosuppression requirements, and early/reversible immune-mediated injuries are required to optimize kidney transplant care. PMID:28270929

  14. Reasons why doctors choose or reject careers in general practice: national surveys

    PubMed Central

    Lambert, Trevor; Goldacre, Raph; Smith, Fay; Goldacre, Michael J

    2012-01-01

    Background Less than one-third of newly qualified doctors in the UK want a career in general practice. The English Department of Health expects that half of all newly qualified doctors will become GPs. Aim To report on the reasons why doctors choose or reject careers in general practice, comparing intending GPs with doctors who chose hospital careers. Design and setting Questionnaire surveys in all UK medical graduates in selected qualification years. Method Questions about specialty career intentions and motivations, put to the qualifiers of 1993, 1996, 1999, 2000, 2002, 2005, 2008, and 2009, 1 year after qualification, and at longer time intervals thereafter. Results ‘Enthusiasm for and commitment to the specialty’ was a very important determinant of choice for intending doctors, regardless of chosen specialty. ‘Hours and working conditions’ were a strong influence for intending GPs (cited as having had ‘a great deal’ of influence by 75% of intending GPs in the first year after qualification), much more so than for doctors who wanted a hospital career (cited by 30%). Relatively few doctors had actually considered general practice seriously but then rejected it; 78% of the doctors who rejected general practice gave ‘job content’ as their reason, compared with 32% of doctors who rejected other specialties. Conclusion The shortfall of doctors wanting a career in general practice is not accounted for by doctors considering and rejecting it. Many do not consider it at all. There are very distinctive factors that influence choice for, and rejection of, general practice. PMID:23211266

  15. NOD-scid IL2rγnull (NSG) Mouse Model of Human Skin Transplantation and Allograft Rejection

    PubMed Central

    Racki, Waldemar J.; Covassin, Laurence; Brehm, Michael; Pino, Stephen; Ignotz, Ronald; Dunn, Raymond; Laning, Joseph; Graves, Susannah K.; Rossini, Aldo A.; Shultz, Leonard D.; Greiner, Dale L.

    2010-01-01

    Background Transplantation of human skin on immunodeficient mice that support engraftment with functional human immune systems would be an invaluable tool for investigating mechanisms involved in wound healing and transplantation. NOD-scid IL2rγnull (NSG) readily engraft with human immune systems but human skin graft integrity is poor. In contrast, human skin graft integrity is excellent on CB17-scid bg (SCID.bg) mice, but they engraft poorly with human immune systems. Methods Human skin grafts transplanted onto immunodeficient NSG, SCID.bg, and other immunodeficient strains were evaluated for graft integrity, preservation of graft endothelium and their ability to be rejected following engraftment of allogeneic peripheral blood mononuclear cells (PBMC). Results Human skin transplanted onto NSG mice develops an inflammatory infiltrate, consisting predominately of host Gr1+ cells, that is detrimental to the survival of human endothelium in the graft. Treatment of graft recipients with anti-Gr1 antibody reduces this cellular infiltrate, preserves graft endothelium, and promotes wound healing, tissue development and graft remodeling. Excellent graft integrity of the transplanted skin includes multilayered stratified human epidermis, well developed human vasculature, human fibroblasts and passenger leukocytes. Injection of unfractionated, CD4 or CD8 allogeneic human PBMC induces a rapid destruction of the transplanted skin graft. Conclusions NSG mice treated with anti-Gr1 antibody provide a model optimized for both human skin graft integrity and engraftment of a functional human immune system. This model provides the opportunity to investigate mechanisms orchestrating inflammation, wound healing, revascularization, tissue remodeling, and allograft rejection and can provide guidance for improving outcomes following clinical transplantation. PMID:20134397

  16. Background Analysis for the SNO+ Experiment

    NASA Astrophysics Data System (ADS)

    Wilson, J. R.; Langrock, S.; Arushanova, E.; Liggins, B. P. M.; SNO+ Collaboration

    2017-09-01

    SNO+ aims to conduct a world leading search for neutrino-less double beta decay of 130Te with a 5 year half-life sensitivity of 1.9×1026 years using 3.9 tonnes of natural Tellurium isotropically loaded in 780 tonnes of liquid scintillator. The total background budget within 0.5σ to 1.5σ of the 0νββ energy is 13.4 events per year, dominated by 8B solar neutrinos. We discuss SNO+ analysis strategies to measure the residual Uranium and Thorium chain backgrounds through the timing coincidence of short half-life components 214Bi – 214Po and 212Bi – 212Po. We show that these so-called Bi-Po events can be rejected from the 0νββ region of interest (ROI) with 99.995% efficiency and minimal (<2%) signal sacrifice. Pure samples of Bi-Pos can also be created to accurately measure the rates of Uranium and Thorium decays in-situ. In a fraction of decays, the Polonium alpha decay will occur within the same trigger window as the beta, resulting in a higher energy ‘pile-up’ event. Separate classifications based on the hit timing structure efficiency reject these events with minimal (<1%) signal loss. A final class of background events results from the pile up of higher frequency low energy backgrounds with events such as 2νββ, which would not otherwise contribute to the ROI. We present a final set of of event classifiers developed specifically to reject these events and show that their contribution to the double beta analysis can be reduced to negligible levels.

  17. Swing-Leg Trajectory of Running Guinea Fowl Suggests Task-Level Priority of Force Regulation Rather than Disturbance Rejection

    PubMed Central

    Blum, Yvonne; Vejdani, Hamid R.; Birn-Jeffery, Aleksandra V.; Hubicki, Christian M.; Hurst, Jonathan W.; Daley, Monica A.

    2014-01-01

    To achieve robust and stable legged locomotion in uneven terrain, animals must effectively coordinate limb swing and stance phases, which involve distinct yet coupled dynamics. Recent theoretical studies have highlighted the critical influence of swing-leg trajectory on stability, disturbance rejection, leg loading and economy of walking and running. Yet, simulations suggest that not all these factors can be simultaneously optimized. A potential trade-off arises between the optimal swing-leg trajectory for disturbance rejection (to maintain steady gait) versus regulation of leg loading (for injury avoidance and economy). Here we investigate how running guinea fowl manage this potential trade-off by comparing experimental data to predictions of hypothesis-based simulations of running over a terrain drop perturbation. We use a simple model to predict swing-leg trajectory and running dynamics. In simulations, we generate optimized swing-leg trajectories based upon specific hypotheses for task-level control priorities. We optimized swing trajectories to achieve i) constant peak force, ii) constant axial impulse, or iii) perfect disturbance rejection (steady gait) in the stance following a terrain drop. We compare simulation predictions to experimental data on guinea fowl running over a visible step down. Swing and stance dynamics of running guinea fowl closely match simulations optimized to regulate leg loading (priorities i and ii), and do not match the simulations optimized for disturbance rejection (priority iii). The simulations reinforce previous findings that swing-leg trajectory targeting disturbance rejection demands large increases in stance leg force following a terrain drop. Guinea fowl negotiate a downward step using unsteady dynamics with forward acceleration, and recover to steady gait in subsequent steps. Our results suggest that guinea fowl use swing-leg trajectory consistent with priority for load regulation, and not for steadiness of gait. Swing

  18. Comparative study of decay ratios of disturbance-rejection magnitude optimum method for PI controllers.

    PubMed

    Lumbar, Satja; Vrancić, Damir; Strmcnik, Stanko

    2008-01-01

    One of the key time-domain closed-loop performance requirements is the closed-loop response decay ratio. In this paper, the decay ratios of the disturbance-rejection magnitude optimum (DRMO) tuning method [Vrancić D, Strmcnik S, Kocijan J. Improving disturbance rejection of PI controllers by means of the magnitude optimum method. ISA Trans 2004; 43: 73-84; Vrancić D, Strmcnik S. Achieving optimal disturbance rejection by using the magnitude optimum method. In: Pre-prints of the CSCC'99 conference. 1999. p. 3401-6] are analyzed and compared to decay ratios of two other modern tuning methods, i.e. the Kappa-Tau tuning method (based on time-domain step-response characteristics) [Aström KJ, Högglund T. PID controllers: Theory, design, and tuning. 2nd ed. Instrument Society of America; 1995] and the non-convex optimization tuning method (based on frequency response) [Panagopoulos H, Aström KJ, Hägglund T. Design of PI controllers based on non-convex optimization. Automatica 1998; 34: 585-601; Panagopoulos H, Aström KJ, Hägglund T. Design of PID controllers based on constrained optimisation. IEE Proc Control Theory Appl 2002; 149 (1): 32-40]. It is shown that the DRMO method results in such a closed-loop response that the decay ratio is within a relatively narrow interval when compared to the other two methods.

  19. Prevention trumps treatment of antibody-mediated transplant rejection.

    PubMed

    Knechtle, Stuart J; Kwun, Jean; Iwakoshi, Neal

    2010-04-01

    Belying the spectacular success of solid organ transplantation and improvements in immunosuppressive therapy is the reality that long-term graft survival rates remain relatively unchanged, in large part due to chronic and insidious alloantibody-mediated graft injury. Half of heart transplant recipients develop chronic rejection within 10 years - a daunting statistic, particularly for young patients expecting to achieve longevity by enduring the rigors of a transplant. The current immunosuppressive pharmacopeia is relatively ineffective in preventing late alloantibody-associated chronic rejection. In this issue of the JCI, Kelishadi et al. report that preemptive deletion of B cells prior to heart transplantation in cynomolgus monkeys, in addition to conventional posttransplant immunosuppressive therapy with cyclosporine, markedly attenuated not only acute graft rejection but also alloantibody elaboration and chronic graft rejection. The success of this preemptive strike implies a central role for B cells in graft rejection, and this approach may help to delay or prevent chronic rejection after solid organ transplantation.

  20. Acute antibody-mediated rejection of cardiac transplants.

    PubMed

    Reed, Elaine F; Demetris, Anthony J; Hammond, Elizabeth; Itescu, Silviu; Kobashigawa, Jon A; Reinsmoen, Nancy L; Rodriguez, E Rene; Rose, Marlene; Stewart, Susan; Suciu-Foca, Nicole; Zeevi, Adriana; Fishbein, Michael C

    2006-02-01

    Under the direction of the International Society for Heart and Lung Transplantation, a multidisciplinary review of the cardiac biopsy grading system was undertaken in 2004, with task forces examining the areas of histopathology of rejection, clinical issues, and research. An important new area addressed by the Immunopathology Task Force sub-committee was the clinical and diagnostic criteria for antibody-mediated rejection. This article is a companion paper to the revised working formulation for the standardization of nomenclature in the diagnosis of heart rejection and reviews the published literature documenting the serologic and morphologic evidence that antibody-mediated rejection is clinically significant and associated with graft loss, accelerated transplant-associated coronary artery disease, and death. This article also provides a more in-depth analysis of antibody-mediated rejection developed by the Immunopathology Task Force for revision of the 1990 working formulation for the standardization of nomenclature in the diagnosis of heart rejection.

  1. Total lymphoid irradiation for treatment of intractable cardiac allograft rejection

    SciTech Connect

    Hunt, S.A.; Strober, S.; Hoppe, R.T.; Stinson, E.B. )

    1991-03-01

    The ability of postoperative total lymphoid irradiation to reverse otherwise intractable cardiac allograft rejection was examined in a group of 10 patients in whom conventional rejection therapy (including pulsed steroids and monoclonal or polyclonal anti-T-cell antibody therapy) had failed to provide sustained freedom from rejection. Follow-up periods range from 73 to 1119 days since the start of total lymphoid irradiation. No patient died or sustained serious morbidity because of the irradiation. Three patients have had no further rejection (follow-up periods, 105 to 365 days). Two patients died--one in cardiogenic shock during the course of total lymphoid irradiation, the other with recurrent rejection caused by noncompliance with his medical regimen. Total lymphoid irradiation appears to be a safe and a moderately effective immunosuppressive modality for 'salvage' therapy of cardiac allograft rejection unresponsive to conventional therapy.

  2. The relations between secrecy, rejection sensitivity and autonomy-connectedness.

    PubMed

    Wismeijer, Andreas A J; Van Assen, Marcel A L M; Bekker, Marrie H J

    2014-01-01

    The aim of this study was to examine the effects of two attachment-related variables on secrecy: rejection sensitivity and autonomy-connectedness. We hypothesized that rejection sensitivity is positively associated with secrecy, and autonomy-connectedness negatively with rejection sensitivity and secrecy. These hypotheses were generally corroborated in a sample of 303 university students. Moreover, we found that autonomy-connectedness at least partly explained the association between rejection sensitivity and secrecy. Self-awareness was negatively related to secrecy, suggesting that being aware of what one needs and thinks and being able to realize one's needs in social interactions reduce the tendency to keep secrets. In addition, interesting gender effects were found suggesting that men have a higher tendency to have secrets than women after controlling for the effects of autonomy-connectedness and rejection sensitivity. Our findings deepen the insight into possible reasons behind established associations between rejection sensitivity and secrecy, and may have clinical implications.

  3. Rejection Sensitivity in Late Adolescence: Social and Emotional Sequelae

    PubMed Central

    Marston, Emily G.; Hare, Amanda; Allen, Joseph P.

    2010-01-01

    This study used longitudinal, multi-reporter data, in a community sample, to examine the role of rejection sensitivity in late adolescents’ social and emotional development. Rejection sensitivity was linked to a relative increase in adolescent depressive and anxiety symptoms over a three-year period, even after accounting for teens’ baseline level of social competence. Additionally, reciprocal relationships emerged between rejection sensitivity and internalizing symptoms. Rejection sensitivity was also linked to relative decreases in peer-reports of teens’ social competence over a three-year period. Consistent with research on gendered socialization, males reported higher levels of rejection sensitivity than females at age 16 and 17. Results are interpreted as highlighting the importance of rejection sensitivity in understanding late adolescent social and emotional development. PMID:21113326

  4. The rejection-rage contingency in borderline personality disorder.

    PubMed

    Berenson, Kathy R; Downey, Geraldine; Rafaeli, Eshkol; Coifman, Karin G; Paquin, Nina Leventhal

    2011-08-01

    Though long-standing clinical observation reflected in the Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.) suggests that the rage characteristic of borderline personality disorder (BPD) often appears in response to perceived rejection, the role of perceived rejection in triggering rage in BPD has never been empirically tested. Extending basic personality research on rejection sensitivity to a clinical sample, a priming-pronunciation experiment and a 21-day experience-sampling diary examined the contingent relationship between perceived rejection and rage in participants diagnosed with BPD compared with healthy controls. Despite the differences in these 2 assessment methods, the indices of rejection-contingent rage that they both produced were elevated in the BPD group and were strongly interrelated. They provide corroborating evidence that reactions to perceived rejection significantly explain the rage seen in BPD. © 2011 American Psychological Association

  5. The Rejection-Rage Contingency in Borderline Personality Disorder

    PubMed Central

    Berenson, Kathy R.; Downey, Geraldine; Rafaeli, Eshkol; Coifman, Karin; Leventhal, Nina

    2011-01-01

    Though longstanding clinical observation reflected in the DSM-IV suggests that the rage characteristic of borderline personality disorder (BPD) often appears in response to perceived rejection, the role of perceived rejection in triggering rage in BPD has never been empirically tested. Extending basic personality research on rejection sensitivity to a clinical sample, a priming-pronunciation experiment and a 21-day experience-sampling diary examined the contingent relationship between perceived rejection and rage in participants diagnosed with BPD compared to healthy controls. Despite the differences in these two assessment methods, the indices of rejection-contingent rage that they produced were both elevated in the BPD group, and were strongly interrelated. They provide corroborating evidence that reactions to perceived rejection significantly explain the rage seen in BPD. PMID:21500875

  6. Control loop noise rejection using fuzzy logic.

    PubMed

    Hay, Glen; Svrcek, William; Ross, Timothy; Young, Brent

    2005-10-01

    This paper describes an application of fuzzy logic to noise rejection in a control loop. This new use of fuzzy logic solves the problem of sluggish control loop response when using a set-point range to stop constant valve chattering due to noise in the output signal being sent to a control valve. Multiple related variables and a general understanding of their inter-relationship must be available for this method to be successfully applied. An overview of the specific fuzzy logic method used for this application is presented along with guidelines for the practical application. In addition, this paper includes results from the successful implementation of fuzzy logic to a control loop on a pilot plant distillation column.

  7. Enhanced IMC design of load disturbance rejection for integrating and unstable processes with slow dynamics.

    PubMed

    Liu, Tao; Gao, Furong

    2011-04-01

    In view of the deficiencies in existing internal model control (IMC)-based methods for load disturbance rejection for integrating and unstable processes with slow dynamics, a modified IMC-based controller design is proposed to deal with step- or ramp-type load disturbance that is often encountered in engineering practices. By classifying the ways through which such load disturbance enters into the process, analytical controller formulae are correspondingly developed, based on a two-degree-of-freedom (2DOF) control structure that allows for separate optimization of load disturbance rejection from setpoint tracking. An obvious merit is that there is only a single adjustable parameter in the proposed controller, which in essence corresponds to the time constant of the closed-loop transfer function for load disturbance rejection, and can be monotonically tuned to meet a good trade-off between disturbance rejection performance and closed-loop robust stability. At the same time, robust tuning constraints are given to accommodate process uncertainties in practice. Illustrative examples from the recent literature are used to show effectiveness and merits of the proposed method for different cases of load disturbance.

  8. Immune cells detection of the in vivo rejecting heart in USPIO-enhanced magnetic resonance imaging.

    PubMed

    Chang, Hsun-Hsien; Moura, José M F; Wu, Yijen L; Ho, Chien

    2006-01-01

    Contrast-enhanced magnetic resonance imaging (MRI) is useful to study the infiltration of immune cells, in particular macrophages. Contrast agents, for example ultra-small superparamagnetic iron oxide (USPIO) particles, administered intravenously into the blood stream will be engulfed by macrophages circulating in the circulation system. When a transplanted heart rejects, macrophages and other immune cells will infiltrate the rejecting tissue. Imaged by T*2 weighted MRI, USPIO-labeled macrophages will display dark pixel intensities. Detecting the presence of USPIO particles in the images facilitates the study of heart rejection. We cast the problem of detecting the presence of USPIO-labeled myocardium in the framework of spectral graph theory, and treat our decision function as a level set function on the image. The pixels with positive level set values correspond to the presence of immune cells, and negative to the absence. When the image is modeled by a graph, the spectral analysis of the graph Laplacian provides a basis to represent the level set function. We develop from the Cheeger constant of the graph an objective functional of the level set function. The minimization of the objective leads to the optimal level set function. Experimental results suggest the feasibility of our approach in the study of rejecting hearts.

  9. Cell-Free DNA and Active Rejection in Kidney Allografts.

    PubMed

    Bloom, Roy D; Bromberg, Jonathan S; Poggio, Emilio D; Bunnapradist, Suphamai; Langone, Anthony J; Sood, Puneet; Matas, Arthur J; Mehta, Shikha; Mannon, Roslyn B; Sharfuddin, Asif; Fischbach, Bernard; Narayanan, Mohanram; Jordan, Stanley C; Cohen, David; Weir, Matthew R; Hiller, David; Prasad, Preethi; Woodward, Robert N; Grskovic, Marica; Sninsky, John J; Yee, James P; Brennan, Daniel C

    2017-07-01

    Histologic analysis of the allograft biopsy specimen is the standard method used to differentiate rejection from other injury in kidney transplants. Donor-derived cell-free DNA (dd-cfDNA) is a noninvasive test of allograft injury that may enable more frequent, quantitative, and safer assessment of allograft rejection and injury status. To investigate this possibility, we prospectively collected blood specimens at scheduled intervals and at the time of clinically indicated biopsies. In 102 kidney recipients, we measured plasma levels of dd-cfDNA and correlated the levels with allograft rejection status ascertained by histology in 107 biopsy specimens. The dd-cfDNA level discriminated between biopsy specimens showing any rejection (T cell-mediated rejection or antibody-mediated rejection [ABMR]) and controls (no rejection histologically), P<0.001 (receiver operating characteristic area under the curve [AUC], 0.74; 95% confidence interval [95% CI], 0.61 to 0.86). Positive and negative predictive values for active rejection at a cutoff of 1.0% dd-cfDNA were 61% and 84%, respectively. The AUC for discriminating ABMR from samples without ABMR was 0.87 (95% CI, 0.75 to 0.97). Positive and negative predictive values for ABMR at a cutoff of 1.0% dd-cfDNA were 44% and 96%, respectively. Median dd-cfDNA was 2.9% (ABMR), 1.2% (T cell-mediated types ≥IB), 0.2% (T cell-mediated type IA), and 0.3% in controls (P=0.05 for T cell-mediated rejection types ≥IB versus controls). Thus, dd-cfDNA may be used to assess allograft rejection and injury; dd-cfDNA levels <1% reflect the absence of active rejection (T cell-mediated type ≥IB or ABMR) and levels >1% indicate a probability of active rejection. Copyright © 2017 by the American Society of Nephrology.

  10. Prognostic factors for corneal graft recovery after severe corneal graft rejection following penetrating keratoplasty

    PubMed Central

    2013-01-01

    Background To investigate the outcome and prognostic factors for corneal graft recovery after severe corneal graft rejection following penetrating keratoplasty (PKP) treated with topical and systemic steroids. Methods Fifty-eight eyes in 58 patients with severe corneal graft rejection following PKP were treated with topical and systemic steroids. Factors affecting the reversibility and maintenance of graft transparency were analyzed. Results Graft transparency was restored in 37 of 58 eyes (63.8%). Clarity of the graft was maintained in 25 of 37 eyes after transparency was restored, while corneal decompensation developed at a mean of 6.0 ± 4.3 months in the remainder. The interval between rejection and treatment with systemic steroids was shorter in cases that recovered graft transparency (OR, 0.88, 95% CI. 0.80–0.97, P = 0.0093). Corneal decompensation after the recovery of corneal transparency tend to occur in cases of regraft (OR, 0.09, 95% CI. 0.01–0.54, P = 0.0091). Conclusions Severe corneal graft rejection after PKP was reversible in approximately two-thirds of the cases, with graft transparency being maintained in two-thirds of them when treated with both topical and systemic steroids. Early treatment confers a benefit in terms of the recovery of graft transparency. PMID:23432898

  11. Reduction of Acute Rejection by Bone Marrow Mesenchymal Stem Cells during Rat Small Bowel Transplantation

    PubMed Central

    Zhang, Wen; Wu, Ben-Juan; Fu, Nan-Nan; Zheng, Wei-Ping; Don, Chong; Shen, Zhong-Yang

    2014-01-01

    Background Bone marrow mesenchymal stem cells (BMMSCs) have shown immunosuppressive activity in transplantation. This study was designed to determine whether BMMSCs could improve outcomes of small bowel transplantation in rats. Methods Heterotopic small bowel transplantation was performed from Brown Norway to Lewis rats, followed by infusion of BMMSCs through the superficial dorsal veins of the penis. Controls included rats infused with normal saline (allogeneic control), isogeneically transplanted rats (BN-BN) and nontransplanted animals. The animals were sacrificed after 1, 5, 7 or 10 days. Small bowel histology and apoptosis, cytokine concentrations in serum and intestinal grafts, and numbers of T regulatory (Treg) cells were assessed at each time point. Results Acute cellular rejection occurred soon after transplantation and became aggravated over time in the allogeneic control rats, with increase in apoptosis, inflammatory response, and T helper (Th)1/Th2 and Th17/Treg-related cytokines. BMMSCs significantly attenuated acute cellular rejection, reduced apoptosis and suppressed the concentrations of interleukin (IL)-2, IL-6, IL-17, IL-23, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ while upregulating IL-10 and transforming growth factor (TGF)-β expression and increasing Treg levels. Conclusion BMMSCs improve the outcomes of allogeneic small bowel transplantation by attenuating the inflammatory response and acute cellular rejection. Treatment with BMMSCs may overcome acute cellular rejection in small bowel transplantation. PMID:25500836

  12. Rejection Sensitivity, Jealousy, and the Relationship to Interpersonal Aggression.

    PubMed

    Murphy, Anna M; Russell, Gemma

    2016-01-21

    The development and maintenance of interpersonal relationships lead individuals to risk rejection in the pursuit of acceptance. Some individuals are predisposed to experience a hypersensitivity to rejection that is hypothesized to be related to jealous and aggressive reactions within interpersonal relationships. The current study used convenience sampling to recruit 247 young adults to evaluate the relationship between rejection sensitivity, jealousy, and aggression. A mediation model was used to test three hypotheses: Higher scores of rejection sensitivity would be positively correlated to higher scores of aggression (Hypothesis 1); higher scores of rejection sensitivity would be positively correlated to higher scores of jealousy (Hypothesis 2); jealousy would mediate the relationship between rejection sensitivity and aggression (Hypothesis 3). Study results suggest a tendency for individuals with high rejection sensitivity to experience higher levels of jealousy, and subsequently have a greater propensity for aggression, than individuals with low rejection sensitivity. Future research that substantiates a link between hypersensitivity to rejection, jealousy, and aggression may provide an avenue for prevention, education, or intervention in reducing aggression within interpersonal relationships.

  13. WILLIAM SEAL REJECTING AN INCOMPLETE OR IMPROPERLY SET BEARDSLEY AND ...

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

    WILLIAM SEAL REJECTING AN INCOMPLETE OR IMPROPERLY SET BEARDSLEY AND PIPER ROTOMOLD CORMATIC CORE. - Southern Ductile Casting Company, Core Making, 2217 Carolina Avenue, Bessemer, Jefferson County, AL

  14. Automatic online embolus detection and artifact rejection with the first multifrequency transcranial Doppler.

    PubMed

    Brucher, Rainer; Russell, David

    2002-08-01

    The goal of this study was to assess the first multifrequency transcranial Doppler system specially developed for online automatic detection of cerebral microemboli. The multifrequency Doppler instrumentation insonates simultaneously with 2.0- and 2.5-MHz frequencies. The detection threshold for embolus detection used in this study was a relative Doppler energy increase of >20 dB. ms, at which point the Doppler power increase was at least 5 dB and lasted >4 ms above the background energy. Four parameters were used in an optimized binary decision tree to recognize emboli: quarter Doppler shift, maximum duration limit, reference gate, and bidirectional enhancement. In in vitro studies, 200 plastic microspheres (80 micro m), 200 gas bubbles (8 to 25 micro m), and 600 artifacts were studied in a pulsatile closed-loop system. In vivo studies were carried out for 1 hour in 15 patients with mechanical heart valves and in 45 patients with carotid stenosis. This gave a total of 60 hours of online automatic monitoring in patients. All 400 plastic spheres and microbubbles were automatically detected and correctly classified. Of the 600 artifacts, 596 (99.3%) were correctly classified as artifacts, and 4 (0.7%) were incorrectly identified as emboli (kappa=0.992, P<0.001). The experienced observer detected a total of 554 emboli and 800 artifacts in the heart valve (521 emboli, 400 artifacts) and carotid stenosis (33 emboli, 400 artifacts) patients. With multifrequency Doppler, 546 of these emboli (98.6%) and 791 of these artifacts (98.9%) were automatically detected and correctly classified as embolus or artifact (kappa=0.953, P<0.0001). We found that multifrequency transcranial Doppler had a relatively high sensitivity and specificity when used to automatically detect cerebral microemboli and reject artifacts online.

  15. Comparison of Speech Perception in Background Noise with Acceptance of Background Noise in Aided and Unaided Conditions.

    ERIC Educational Resources Information Center

    Nabelek, Anna K.; Tampas, Joanna W.; Burchfield, Samuel B.

    2004-01-01

    l, speech perception in noiseBackground noise is a significant factor influencing hearing-aid satisfaction and is a major reason for rejection of hearing aids. Attempts have been made by previous researchers to relate the use of hearing aids to speech perception in noise (SPIN), with an expectation of improved speech perception followed by an…

  16. Peer Rejection and Friendships in Children with Attention-Deficit/Hyperactivity Disorder: Contributions to Long-Term Outcomes

    ERIC Educational Resources Information Center

    Mrug, Sylvie; Molina, Brooke S. G.; Hoza, Betsy; Gerdes, Alyson C.; Hinshaw, Stephen P.; Hechtman, Lily; Arnold, L. Eugene

    2012-01-01

    Even after evidence-based treatment, Attention-Deficit/Hyperactivity Disorder (ADHD) is associated with poor long-term outcomes. These outcomes may be partly explained by difficulties in peer functioning, which are common among children with ADHD and which do not respond optimally to standard ADHD treatments. We examined whether peer rejection and…

  17. 100-Gbit/s PDM-QPSK coherent receiver with wide dynamic range and excellent common-mode rejection ratio.

    PubMed

    Murata, Koichi; Saida, Takashi; Sano, Kimikazu; Ogawa, Ikuo; Fukuyama, Hiroyuki; Kasahara, Ryoichi; Muramoto, Yoshifumi; Nosaka, Hideyuki; Tsunashima, Satoshi; Mizuno, Takayuki; Tanobe, Hiromasa; Hattori, Kuninori; Yoshimatsu, Toshihide; Kawakami, Hiroto; Yoshida, Eiji

    2011-12-12

    We report the design and fabrication of a hybrid-integration-type coherent receiver. We optimize the receiver building blocks, and achieve a -25-dB common-mode rejection ratio and a 20-dB signal input power dynamic range.

  18. Background model for the Majorana Demonstrator

    DOE PAGES

    Cuesta, C.; Abgrall, N.; Aguayo, E.; ...

    2015-01-01

    The Majorana Collaboration is constructing a system containing 40 kg of HPGe detectors to demonstrate the feasibility and potential of a future tonne-scale experiment capable of probing the neutrino mass scale in the inverted-hierarchy region. To realize this, a major goal of the Majorana Demonstrator is to demonstrate a path forward to achieving a background rate at or below 1 cnt/(ROI-t-y) in the 4 keV region of interest around the Q-value at 2039 keV. This goal is pursued through a combination of a significant reduction of radioactive impurities in construction materials with analytical methods for background rejection, for example usingmore » powerful pulse shape analysis techniques profiting from the p-type point contact HPGe detectors technology. The effectiveness of these methods is assessed using simulations of the different background components whose purity levels are constrained from radioassay measurements.« less

  19. Background model for the Majorana Demonstrator

    SciTech Connect

    Cuesta, C.; Abgrall, N.; Aguayo, E.; Avignone, III, F. T.; Barabash, A. S.; Bertrand, F. E.; Boswell, M.; Brudanin, V.; Busch, M.; Byram, D.; Caldwell, A. S.; Chan, Y -D.; Christofferson, C. D.; Combs, D. C.; Detwiler, J. A.; Doe, P. J.; Efremenko, Yu.; Egorov, V.; Ejiri, H.; Elliott, S. R.; Fast, J. E.; Finnerty, P.; Fraenkle, F. M.; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guiseppe, V.; Gusev, K.; Hallin, A.; Hazama, R.; Hegai, A.; Henning, R.; Hoppe, E. W.; Howard, S.; Howe, M. A.; Keeter, K. J.; Kidd, M. F.; Kochetov, O.; Konovalov, S. I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J.; Leviner, L. E.; Loach, J. C.; MacMullin, J.; MacMullin, S.; Martin, R. D.; Meijer, S.; Mertens, S.; Nomachi, M.; Orrell, J. L.; O'Shaughnessy, C.; Overman, N. R.; Phillips, D. G.; Poon, W. W. P.; Pushkin, K.; Radford, D. C.; Rager, J.; Rielage, K.; Robertson, R. G. H.; Romero-Romero, E.; Ronquest, M. C.; Schubert, A. G.; Shanks, B.; Shima, T.; Shirchenko, M.; Snavely, K. K.; Snyder, N.; Suriano, A. M.; Thompson, J.; Timkin, V.; Tornow, W.; Trimble, J. E.; Varner, R.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Young, A. R.; Yu, C. -H.; Yumatov, V.

    2015-01-01

    The Majorana Collaboration is constructing a system containing 40 kg of HPGe detectors to demonstrate the feasibility and potential of a future tonne-scale experiment capable of probing the neutrino mass scale in the inverted-hierarchy region. To realize this, a major goal of the Majorana Demonstrator is to demonstrate a path forward to achieving a background rate at or below 1 cnt/(ROI-t-y) in the 4 keV region of interest around the Q-value at 2039 keV. This goal is pursued through a combination of a significant reduction of radioactive impurities in construction materials with analytical methods for background rejection, for example using powerful pulse shape analysis techniques profiting from the p-type point contact HPGe detectors technology. The effectiveness of these methods is assessed using simulations of the different background components whose purity levels are constrained from radioassay measurements.

  20. Human CD55 Expression Blocks Hyperacute Rejection and Restricts Complement Activation in Gal Knockout Cardiac Xenografts

    PubMed Central

    McGregor, Christopher G.A.; Ricci, Davide; Miyagi, Naoto; Stalboerger, Paul G.; Du, Zeji; Oehler, Elise A.; Tazelaar, Henry D.; Byrne, Guerard W.

    2012-01-01

    Background Transgenic expression of human complement regulatory proteins (hCRPs) reduces the frequency of hyperacute rejection (HAR) in Gal-positive cardiac xenotransplantation. In this study we examine the impact of human CD55 (hCD55) expression on a Gal knock-out (GTKO) background using pig-to-primate heterotopic cardiac xenotransplantation. Methods Cardiac xenotransplantation was performed with GTKO (Group 1; n=6) and GTKO.hCD55 (Group 2; n=5) donor pigs using similar immunosuppression. Cardiac biopsies were obtained 30 minutes after organ reperfusion. Rejection was characterized by histology and immunohistology. Intragraft gene expression, serum non-Gal antibody and antibody recovered from rejected hearts were analyzed. Results HAR of a GTKO heart was observed. Remaining grafts developed delayed xenograft rejection. Median survival was 21 and 28 days for Groups 1 and 2 respectively. Vascular antibody deposition was uniformly detected 30 minutes after organ reperfusion and at explant. A higher frequency of vascular C5b deposition was seen in GTKO organs at explant. Serum non-Gal antibody, antibody recovered from the graft and intragraft gene expression were similar between the groups. Conclusion HAR of GTKO hearts without hCD55 may occur. Expression of hCD55 appeared to restrict local complement activation, but did not improve graft survival. Chronic vascular antibody deposition with evidence of protracted endothelial cell activation was seen. These observations suggest that non-Gal antibody-induced chronic endothelial cell activation coupled to possible haemostatic incompatibilities may be the primary stimulus for DXR of GTKO hearts. To avoid possible HAR, future clinical studies should employ donors expressing hCRPs in the GTKO background. PMID:22391577

  1. Questions of Degree? Middle-Class Rejection of Higher Education and Intra-Class Differences in Educational Decision-Making

    ERIC Educational Resources Information Center

    Morrison, Andrew

    2011-01-01

    This article is an analysis of middle-class rejection of higher education. The author uses accounts of the educational decision-making of three female students, all identified to be from broadly middle-class backgrounds, from within full-time vocational further education in the United Kingdom, as a means to consider two issues. First, the author…

  2. Autoreject: Automated artifact rejection for MEG and EEG data.

    PubMed

    Jas, Mainak; Engemann, Denis A; Bekhti, Yousra; Raimondo, Federico; Gramfort, Alexandre

    2017-06-20

    We present an automated algorithm for unified rejection and repair of bad trials in magnetoencephalography (MEG) and electroencephalography (EEG) signals. Our method capitalizes on cross-validation in conjunction with a robust evaluation metric to estimate the optimal peak-to-peak threshold - a quantity commonly used for identifying bad trials in M/EEG. This approach is then extended to a more sophisticated algorithm which estimates this threshold for each sensor yielding trial-wise bad sensors. Depending on the number of bad sensors, the trial is then repaired by interpolation or by excluding it from subsequent analysis. All steps of the algorithm are fully automated thus lending itself to the name Autoreject. In order to assess the practical significance of the algorithm, we conducted extensive validation and comparisons with state-of-the-art methods on four public datasets containing MEG and EEG recordings from more than 200 subjects. The comparisons include purely qualitative efforts as well as quantitatively benchmarking against human supervised and semi-automated preprocessing pipelines. The algorithm allowed us to automate the preprocessing of MEG data from the Human Connectome Project (HCP) going up to the computation of the evoked responses. The automated nature of our method minimizes the burden of human inspection, hence supporting scalability and reliability demanded by data analysis in modern neuroscience. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. 45 CFR 1180.36 - Rejection of an application.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ....36 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL FOUNDATION ON THE ARTS... application. (a) The Director rejects an application if: (1) The applicant is not eligible; (2) The applicant... statute or implementing regulations. (b) If the Director rejects an application under this section, the...

  4. 45 CFR 1180.36 - Rejection of an application.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ....36 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL FOUNDATION ON THE ARTS... application. (a) The Director rejects an application if: (1) The applicant is not eligible; (2) The applicant... statute or implementing regulations. (b) If the Director rejects an application under this section, the...

  5. 45 CFR 1180.36 - Rejection of an application.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ....36 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL FOUNDATION ON THE ARTS... application. (a) The Director rejects an application if: (1) The applicant is not eligible; (2) The applicant... statute or implementing regulations. (b) If the Director rejects an application under this section, the...

  6. 45 CFR 1180.36 - Rejection of an application.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ....36 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL FOUNDATION ON THE ARTS... application. (a) The Director rejects an application if: (1) The applicant is not eligible; (2) The applicant... statute or implementing regulations. (b) If the Director rejects an application under this section, the...

  7. 45 CFR 1180.36 - Rejection of an application.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ....36 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL FOUNDATION ON THE ARTS... application. (a) The Director rejects an application if: (1) The applicant is not eligible; (2) The applicant... statute or implementing regulations. (b) If the Director rejects an application under this section, the...

  8. Rejection Sensitivity in Late Adolescence: Social and Emotional Sequelae

    ERIC Educational Resources Information Center

    Marston, Emily G.; Hare, Amanda; Allen, Joseph P.

    2010-01-01

    This study used longitudinal, multireporter data, in a community sample, to examine the role of rejection sensitivity in late adolescents' social and emotional development. Rejection sensitivity was linked to a relative increase in adolescent depressive and anxiety symptoms over a 3-year period, even after accounting for teens' baseline level of…

  9. Heterosexual Rejection and Mate Choice: A Sociometer Perspective

    PubMed Central

    Zhang, Lin; Liu, Shen; Li, Yue; Ruan, Lu-Jun

    2015-01-01

    Previous studies about the effects of social rejection on individuals' social behaviors have produced mixed results and tend to study mating behaviors from a static point of view. However, mate selection in essence is a dynamic process, and therefore sociometer theory opens up a new perspective for studying mating and its underlying practices. Based on this theory and using self-perceived mate value in the relationship between heterosexual rejection and mate choice as a mediating role, this current study examined the effects of heterosexual rejection on mate choice in two experiments. Results showed that heterosexual rejection significantly reduced self-perceived mate value, expectation, and behavioral tendencies, while heterosexual acceptance indistinctively increased these measures. Self-perceived mate value did not serve as a mediator in the relationship between heterosexual rejection and mate expectation, but it mediated the relationship between heterosexual rejection and mating behavior tendencies toward potential objects. Moreover, individuals evaded both rejection and irrelevant people when suffering from rejection. PMID:26648898

  10. 48 CFR 619.505 - Rejecting Small Business Administration recommendations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... STATE SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS Set-Asides for Small Business 619.505 Rejecting Small Business Administration recommendations. The Procurement Executive is the agency head for the... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Rejecting Small Business...

  11. Process Demands of Rejection Mechanisms of Recognition Memory

    ERIC Educational Resources Information Center

    Odegard, Timothy N.; Koen, Joshua D.; Gama, Jorge M.

    2008-01-01

    A surge of research has been conducted to examine memory editing mechanisms that help distinguish accurate from inaccurate memories. In the present experiment, the authors examined the ability of participants to use novelty detection, recollection rejection, and plausibility judgments to reject lures presented on a recognition memory test.…

  12. Peer Rejection in Preschool: Foregrounding Children’s Voices

    ERIC Educational Resources Information Center

    Tay-Lim, Joanna; Gan, Linda

    2013-01-01

    Existing studies on peer rejection are predominantly quantitative in nature and do not adequately engage children’s voices and provide a comprehensive view of the peer rejection phenomenon. There are also limited studies at the preschool level, especially in the Singapore context. This study addresses these limitations by presenting insights into…

  13. 25 CFR 163.18 - Acceptance and rejection of bids.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Acceptance and rejection of bids. 163.18 Section 163.18 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GENERAL FORESTRY REGULATIONS Forest Management and Operations § 163.18 Acceptance and rejection of bids. (a) The high bid received in...

  14. 25 CFR 163.18 - Acceptance and rejection of bids.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Acceptance and rejection of bids. 163.18 Section 163.18 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GENERAL FORESTRY REGULATIONS Forest Management and Operations § 163.18 Acceptance and rejection of bids. (a) The high bid received in...

  15. 25 CFR 163.18 - Acceptance and rejection of bids.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Acceptance and rejection of bids. 163.18 Section 163.18 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GENERAL FORESTRY REGULATIONS Forest Management and Operations § 163.18 Acceptance and rejection of bids. (a) The high bid received in...

  16. 25 CFR 163.18 - Acceptance and rejection of bids.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Acceptance and rejection of bids. 163.18 Section 163.18 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GENERAL FORESTRY REGULATIONS Forest Management and Operations § 163.18 Acceptance and rejection of bids. (a) The high bid received in...

  17. 25 CFR 163.18 - Acceptance and rejection of bids.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Acceptance and rejection of bids. 163.18 Section 163.18 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GENERAL FORESTRY REGULATIONS Forest Management and Operations § 163.18 Acceptance and rejection of bids. (a) The high bid received in...

  18. 48 CFR 914.404 - Rejection of bids.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Rejection of bids. 914.404 Section 914.404 Federal Acquisition Regulations System DEPARTMENT OF ENERGY CONTRACTING METHODS AND CONTRACT TYPES SEALED BIDDING Opening of Bids and Award of Contract 914.404 Rejection of bids....

  19. 48 CFR 914.404 - Rejection of bids.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 5 2012-10-01 2012-10-01 false Rejection of bids. 914.404 Section 914.404 Federal Acquisition Regulations System DEPARTMENT OF ENERGY CONTRACTING METHODS AND CONTRACT TYPES SEALED BIDDING Opening of Bids and Award of Contract 914.404 Rejection of bids....

  20. 48 CFR 914.404 - Rejection of bids.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 5 2013-10-01 2013-10-01 false Rejection of bids. 914.404 Section 914.404 Federal Acquisition Regulations System DEPARTMENT OF ENERGY CONTRACTING METHODS AND CONTRACT TYPES SEALED BIDDING Opening of Bids and Award of Contract 914.404 Rejection of bids....

  1. 48 CFR 914.404 - Rejection of bids.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Rejection of bids. 914.404 Section 914.404 Federal Acquisition Regulations System DEPARTMENT OF ENERGY CONTRACTING METHODS AND CONTRACT TYPES SEALED BIDDING Opening of Bids and Award of Contract 914.404 Rejection of bids....

  2. 48 CFR 914.404 - Rejection of bids.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Rejection of bids. 914.404 Section 914.404 Federal Acquisition Regulations System DEPARTMENT OF ENERGY CONTRACTING METHODS AND CONTRACT TYPES SEALED BIDDING Opening of Bids and Award of Contract 914.404 Rejection of bids....

  3. 48 CFR 1419.505 - Rejecting Small Business Administration recommendations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Rejecting Small Business Administration recommendations. 1419.505 Section 1419.505 Federal Acquisition Regulations System DEPARTMENT OF... Rejecting Small Business Administration recommendations. (a) A written justification in support of the CO's...

  4. Prevalence and characteristics of foal rejection in Arabian mares.

    PubMed

    Juarbe-Díaz, S V; Houpt, K A; Kusunose, R

    1998-09-01

    Separate surveys of Thoroughbred, Paint, and Arabian mare owners revealed a higher than expected rate of foal rejection in Arabian mares. A behavioural history form was submitted by owners of foal rejecting and nonrejecting Arabian mares, and maternal behaviour and management practices compared. Four generation pedigrees of rejecting and nonrejecting Arabian mares were also examined. Foal rejecting mares were more likely to avoid, threaten, squeal at, chase, bite, and kick their foals post partum than nonrejecting mares. Nonrejecting mares were more likely to lick, nicker and defend their foals post partum than rejecting mares. No statistically significant relationship was found between foal rejection and the type of breeding method (natural vs. artificial insemination), the presence of people at birth, the presence of nearby horses at birth, or assistance of the first nursing bout. The presence at least once of 1 of 2 related sires was statistically higher in the pedigrees of rejecting vs. nonrejecting mares. Inherited and learned or environmental factors are likely to affect the expression of foal rejection behaviour.

  5. Rheumatoid course of humoral (vascular) rejection after heart allotransplantation.

    PubMed

    Beletskaya, L V; Kupriyanova, A G; Kormer, A Ya; Mironkov, B L; Kazakov, E N; Shumakov, V I

    2006-09-01

    Analysis of planned endomyocardial biopsy specimens of heart allotransplants from 22 recipients revealed signs of humoral type rejection (slight, medium, and severe) presenting as fixation of IgG, IgM, and complement components (C3, C4d) in 61 of 63 sections. Permanent presence of rejection signs attests to rheumatoid course of this process.

  6. Rejection Sensitivity in Late Adolescence: Social and Emotional Sequelae

    ERIC Educational Resources Information Center

    Marston, Emily G.; Hare, Amanda; Allen, Joseph P.

    2010-01-01

    This study used longitudinal, multireporter data, in a community sample, to examine the role of rejection sensitivity in late adolescents' social and emotional development. Rejection sensitivity was linked to a relative increase in adolescent depressive and anxiety symptoms over a 3-year period, even after accounting for teens' baseline level of…

  7. 32 CFR 274.8 - Bids-revocations-rejections-postponements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Bids-revocations-rejections-postponements. 274.8 Section 274.8 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE... EXPORT LOAN AGREEMENTS § 274.8 Bids-revocations-rejections-postponements. The Secretary of Defense or...

  8. Social Rejection and ADHD in Young Adults: An Analogue Experiment

    ERIC Educational Resources Information Center

    Paulson, James F.; Buermeyer, Curt; Nelson-Gray, Rosemery O.

    2005-01-01

    Poor outcomes in ADHD may be related to problematic social functioning and consequences of social rejection. This study examines how ADHD symptom expression affects mood and social rejection. Working from findings in depression that describe maintenance through negative interpersonal interactions, the authors seek to examine this theory's…

  9. Preadolescent Friendship and Peer Rejection as Predictors of Adult Adjustment.

    ERIC Educational Resources Information Center

    Bagwell, Catherine L.; Newcomb, Andrew F.; Bukowski, William M.

    1998-01-01

    Compared adjustment of 30 young adults who had a stable, reciprocal best friend in fifth grade and 30 who did not. Found that lower peer rejection uniquely predicted overall life status adjustment. Friended preadolescents had higher general self-worth in adulthood, even after controlling for perceived preadolescence competence. Peer rejection and…

  10. Preadolescent Friendship and Peer Rejection as Predictors of Adult Adjustment.

    ERIC Educational Resources Information Center

    Bagwell, Catherine L.; Newcomb, Andrew F.; Bukowski, William M.

    1998-01-01

    Compared adjustment of 30 young adults who had a stable, reciprocal best friend in fifth grade and 30 who did not. Found that lower peer rejection uniquely predicted overall life status adjustment. Friended preadolescents had higher general self-worth in adulthood, even after controlling for perceived preadolescence competence. Peer rejection and…

  11. 48 CFR 219.505 - Rejecting Small Business Administration recommendations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Rejecting Small Business Administration recommendations. 219.505 Section 219.505 Federal Acquisition Regulations System DEFENSE...-Asides for Small Business 219.505 Rejecting Small Business Administration recommendations. (b)...

  12. 48 CFR 1419.505 - Rejecting Small Business Administration recommendations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Administration recommendations. 1419.505 Section 1419.505 Federal Acquisition Regulations System DEPARTMENT OF... Rejecting Small Business Administration recommendations. (a) A written justification in support of the CO's decision to reject the set-aside recommendation shall be approved by the HCA. It shall then be...

  13. 48 CFR 2919.505 - Rejecting Small Business Administration recommendations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Administration recommendations. 2919.505 Section 2919.505 Federal Acquisition Regulations System DEPARTMENT OF... Small Business 2919.505 Rejecting Small Business Administration recommendations. When the SBA Procurement Center Representative appeals a “rejection of an SBA recommendation” as referenced in FAR...

  14. 48 CFR 314.404 - Rejection of bids.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Rejection of bids. 314.404 Section 314.404 Federal Acquisition Regulations System HEALTH AND HUMAN SERVICES CONTRACTING METHODS AND CONTRACT TYPES SEALED BIDDING Opening of Bids and Award of Contract 314.404 Rejection of bids....

  15. On Rejecting Emotional Lures Created by Phonological Neighborhood Activation

    ERIC Educational Resources Information Center

    Starns, Jeffrey J.; Cook, Gabriel I.; Hicks, Jason L.; Marsh, Richard L.

    2006-01-01

    The authors conducted 2 experiments to assess how phonologically related lures are rejected in a false memory paradigm. Some phonological lures were emotional (i.e., taboo) words, and others were not. The authors manipulated the presence of taboo items on the study list and reduced the ability to use controlled rejection strategies by dividing…

  16. Social Rejection and ADHD in Young Adults: An Analogue Experiment

    ERIC Educational Resources Information Center

    Paulson, James F.; Buermeyer, Curt; Nelson-Gray, Rosemery O.

    2005-01-01

    Poor outcomes in ADHD may be related to problematic social functioning and consequences of social rejection. This study examines how ADHD symptom expression affects mood and social rejection. Working from findings in depression that describe maintenance through negative interpersonal interactions, the authors seek to examine this theory's…

  17. 48 CFR 1419.505 - Rejecting Small Business Administration recommendations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Administration recommendations. 1419.505 Section 1419.505 Federal Acquisition Regulations System DEPARTMENT OF... Rejecting Small Business Administration recommendations. (a) A written justification in support of the CO's decision to reject the set-aside recommendation shall be approved by the HCA. It shall then be...

  18. 48 CFR 2919.505 - Rejecting Small Business Administration recommendations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Administration recommendations. 2919.505 Section 2919.505 Federal Acquisition Regulations System DEPARTMENT OF... Small Business 2919.505 Rejecting Small Business Administration recommendations. When the SBA Procurement Center Representative appeals a “rejection of an SBA recommendation” as referenced in FAR...

  19. 48 CFR 219.505 - Rejecting Small Business Administration recommendations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Rejecting Small Business Administration recommendations. 219.505 Section 219.505 Federal Acquisition Regulations System DEFENSE...-Asides for Small Business 219.505 Rejecting Small Business Administration recommendations. (b)...

  20. 48 CFR 2919.505 - Rejecting Small Business Administration recommendations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Administration recommendations. 2919.505 Section 2919.505 Federal Acquisition Regulations System DEPARTMENT OF... Small Business 2919.505 Rejecting Small Business Administration recommendations. When the SBA Procurement Center Representative appeals a “rejection of an SBA recommendation” as referenced in FAR...

  1. 48 CFR 219.505 - Rejecting Small Business Administration recommendations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Rejecting Small Business Administration recommendations. 219.505 Section 219.505 Federal Acquisition Regulations System DEFENSE...-Asides for Small Business 219.505 Rejecting Small Business Administration recommendations. (b)...

  2. 48 CFR 2919.505 - Rejecting Small Business Administration recommendations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Administration recommendations. 2919.505 Section 2919.505 Federal Acquisition Regulations System DEPARTMENT OF... Small Business 2919.505 Rejecting Small Business Administration recommendations. When the SBA Procurement Center Representative appeals a “rejection of an SBA recommendation” as referenced in FAR...

  3. 48 CFR 1419.505 - Rejecting Small Business Administration recommendations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Administration recommendations. 1419.505 Section 1419.505 Federal Acquisition Regulations System DEPARTMENT OF... Rejecting Small Business Administration recommendations. (a) A written justification in support of the CO's decision to reject the set-aside recommendation shall be approved by the HCA. It shall then be...

  4. 48 CFR 219.505 - Rejecting Small Business Administration recommendations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Rejecting Small Business Administration recommendations. 219.505 Section 219.505 Federal Acquisition Regulations System DEFENSE...-Asides for Small Business 219.505 Rejecting Small Business Administration recommendations. (b)...

  5. 48 CFR 1419.505 - Rejecting Small Business Administration recommendations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Administration recommendations. 1419.505 Section 1419.505 Federal Acquisition Regulations System DEPARTMENT OF... Rejecting Small Business Administration recommendations. (a) A written justification in support of the CO's decision to reject the set-aside recommendation shall be approved by the HCA. It shall then be...

  6. 48 CFR 219.505 - Rejecting Small Business Administration recommendations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Rejecting Small Business Administration recommendations. 219.505 Section 219.505 Federal Acquisition Regulations System DEFENSE...-Asides for Small Business 219.505 Rejecting Small Business Administration recommendations. (b)...

  7. 48 CFR 2919.505 - Rejecting Small Business Administration recommendations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Administration recommendations. 2919.505 Section 2919.505 Federal Acquisition Regulations System DEPARTMENT OF... Small Business 2919.505 Rejecting Small Business Administration recommendations. When the SBA Procurement Center Representative appeals a “rejection of an SBA recommendation” as referenced in FAR...

  8. The Peer Review Process: Acceptances, Revisions, and Outright Rejections.

    ERIC Educational Resources Information Center

    Richardson, John V., Jr.

    2002-01-01

    Describes the manuscript review process at "Library Quarterly," discussing the accepted manuscript; the revise and resubmit manuscript; the rejected manuscript; and unethical conduct. Provides a "Library Quarterly" time to decisions table (overall days to decide acceptance, revision, or reject) by year (1996-2000). Includes the…

  9. Peer victimization and peer rejection during early childhood.

    PubMed

    Godleski, Stephanie A; Kamper, Kimberly E; Ostrov, Jamie M; Hart, Emily J; Blakely-McClure, Sarah J

    2015-01-01

    The development and course of the subtypes of peer victimization is a relatively understudied topic despite the association of victimization with important developmental and clinical outcomes. Moreover, understanding potential predictors, such as peer rejection and emotion regulation, in early childhood may be especially important to elucidate possible bidirectional pathways between relational and physical victimization and rejection. The current study (N = 97) was designed to explore several gaps and limitations in the peer victimization and peer rejection literature. In particular, the prospective associations between relational and physical victimization and peer rejection over the course of 3.5 months during early childhood (i.e., 3 to 5 years old) were investigated in an integrated model. The study consisted of 97 (42 girls) preschool children recruited from four early childhood schools in the northeast of the United States. Using observations, research assistant report, and teacher report, relational and physical aggression, relational and physical victimization, peer rejection, and emotion regulation were measured in a short-term longitudinal study. Path analyses were conducted to test the overall hypothesized model. Peer rejection was found to predict increases in relational victimization. In addition, emotion regulation was found to predict decreases in peer rejection and physical victimization. Implications for research and practice are discussed, including teaching coping strategies for peer rejection and emotional distress.

  10. Selecting Social Intervention Techniques for Aggressive Rejected Children.

    ERIC Educational Resources Information Center

    Bierman, Karen Linn; Schwartz, Lori A.

    Based upon evidence that peer rejection is a marker variable asociated with maladaptive social-emotional development and the risk of later maladjustment, psychologists have focused both on understanding the factors contributing to peer rejection and on preventive interventions designed to remediate social adjustment problems evident in grade…

  11. Peer victimization and peer rejection during early childhood

    PubMed Central

    Godleski, Stephanie A.; Kamper, Kimberly E.; Ostrov, Jamie M.; Hart, Emily J.; Blakely-McClure, Sarah J.

    2014-01-01

    Objective The development and course of the subtypes of peer victimization is a relatively understudied topic despite the association of victimization with important developmental and clinical outcomes. Moreover, understanding potential predictors, such as peer rejection and emotion regulation, in early childhood may be especially important to elucidate possible bi-directional pathways between relational and physical victimization and rejection. The current study (N = 97) was designed to explore several gaps and limitations in the peer victimization and peer rejection literature. In particular, the prospective associations between relational and physical victimization and peer rejection over the course of 3.5 months during early childhood (i.e., 3- to 5- years-old) were investigated in an integrated model. Method The study consisted of 97 (42 girls) preschool children recruited from four early childhood schools in the northeast of the US. Using observations, research assistant report and teacher report, relational and physical aggression, relational and physical victimization, peer rejection, and emotion regulation were measured in a short-term longitudinal study. Path analyses were conducted to test the overall hypothesized model. Results Peer rejection was found to predict increases in relational victimization. In addition, emotion regulation was found to predict decreases in peer rejection and physical victimization. Conclusions Implications for research and practice are discussed, including teaching coping strategies for peer rejection and emotional distress. PMID:25133659

  12. Aggressive and Nonaggressive Rejected Students: An Analysis of Their Differences

    ERIC Educational Resources Information Center

    Lopez, Estefania Estevez; Olaizola, Juan Herrero; Ferrer, Belen Martinez; Ochoa, Gonzalo Musitu

    2006-01-01

    The present study aimed to analyze differences between aggressive and nonaggressive rejected students in four sets of variables: personal, family, school, and social. Participants in the study were 843 Spanish adolescents ranging in age from 11 to 16 years old, of whom 47% were boys. Results indicated that these two subgroups of rejected students…

  13. Peer Rejection in Preschool: Foregrounding Children’s Voices

    ERIC Educational Resources Information Center

    Tay-Lim, Joanna; Gan, Linda

    2013-01-01

    Existing studies on peer rejection are predominantly quantitative in nature and do not adequately engage children’s voices and provide a comprehensive view of the peer rejection phenomenon. There are also limited studies at the preschool level, especially in the Singapore context. This study addresses these limitations by presenting insights into…

  14. [Acculturation orientations and psychosocial adaptation among adolescents with immigrant background].

    PubMed

    Goutaudier, N; Chauchard, E; Melioli, T; Valls, M; van Leeuwen, N; Chabrol, H

    2015-09-01

    The aim of the study was to explore the typology of adolescents with immigrant background based on the orientations of acculturation and to estimate the psychosocial adaptation of the various subtypes. A sample of 228 French high school students with an immigrant background completed a questionnaire assessing acculturation orientations (Immigrant Acculturation Scale; Barrette et al., 2004), antisocial behaviors, depressive symptoms and self-esteem. Cluster analysis based on acculturation orientations was performed using the k-means method. Cluster analysis produced four distinct acculturation profiles: bicultural (31%), separated (28%), marginalized (21%), and assimilated-individualistic (20%). Adolescents in the separated and marginalized clusters, both characterized by rejection of the host culture, reported higher levels of antisocial behavior. Depressive symptoms and self-esteem did not differ between clusters. Several hypotheses may explain the association between separation and delinquency. First, separation and rejection of the host culture may lead to rebellious behavior such as delinquency. Conversely, delinquent behavior may provoke rejection or discrimination by peers or school, or legal sanctions that induce a reciprocal process of rejection of the host culture and separation. The relationship between separation and antisocial behavior may be bidirectional, each one reinforcing the other, resulting in a negative spiral. This study confirms the interest of the study of the orientations of acculturation in the understanding of the antisocial behavior of adolescents with immigrant background. Copyright © 2014 L’Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.

  15. The role of egg-nest contrast in the rejection of brood parasitic eggs.

    PubMed

    Aidala, Zachary; Croston, Rebecca; Schwartz, Jessica; Tong, Lainga; Hauber, Mark E

    2015-04-15

    Hosts of avian brood parasites can avoid the reproductive costs of raising genetically unrelated offspring by rejecting parasitic eggs. The perceptual cues and controls mediating parasitic egg discrimination and ejection are well studied: hosts are thought to use differences in egg color, brightness, maculation, size and shape to discriminate between their own and foreign eggs. Most theories of brood parasitism implicitly assume that the primary criteria to which hosts attend when discriminating eggs are differences between the eggs themselves. However, this assumption is confounded by the degree to which chromatic and achromatic characteristics of the nest lining co-vary with egg coloration, so that egg-nest contrast per se might be the recognition cue driving parasitic egg detection. Here, we systematically tested whether and how egg-nest contrast itself contributes to foreign egg discrimination. In an artificial parasitism experiment, we independently manipulated egg color and nest lining color of the egg-ejector American robin (Turdus migratorius), a host of the obligate brood parasitic brown-headed cowbird (Molothrus ater). We hypothesized that the degree of contrast between foreign eggs and the nest background would affect host egg rejection behavior. We predicted that experimentally decreasing egg-nest chromatic and achromatic contrast (i.e. rendering parasitic eggs more cryptic against the nest lining) would decrease rejection rates, while increasing egg-nest contrast would increase rejection rates. In contrast to our predictions, egg-nest contrast was not a significant predictor of egg ejection patterns. Instead, egg color significantly predicted responses to parasitism. We conclude that egg-egg differences are the primary drivers of egg rejection in this system. Future studies should test for the effects of egg-nest contrast per se in predicting parasitic egg recognition in other host-parasite systems, including those hosts building enclosed nests and

  16. Role of T Cell-Specific NF-κB in Islet Allograft Rejection

    PubMed Central

    Porras, Delia Lozano; Wang, Ying; Zhou, Ping; Molinero, Luciana L; Alegre, Maria-Luisa

    2012-01-01

    Background Pancreatic islet transplantation has the potential to cure Type 1 Diabetes (T1D), a chronic lifelong disease, but its clinical applicability is limited by allograft rejection. Nuclear factor κB (NF-κB) is a transcription factor important for survival and differentiation of T cells. In this study, we tested whether NF-κB in T cells is required for the rejection of islet allografts. Methods Mice expressing a super-repressor form of NF-κB selectively in T cell (IκBαΔN-Tg mice) with or without the anti-apoptotic factor Bcl-xL, or mice with impaired TCR-and BCR-driven NF-κB activity (CARMA1-KO mice) were rendered diabetic and transplanted with islet allografts. Secondary skin transplantation in long-term acceptors of islet allografts was used to test for development of donor-specific tolerance. Immune infiltration of the transplanted islets was examined by immunofluorescence. TCR-transgenic CD4+ T cells were used to follow T cell priming and differentiation. Results Islet allograft survival was prolonged in IκBαΔN-Tg mice, although the animals did not develop donor-specific tolerance. Reduced NF-κB activity did not prevent T cell priming or differentiation but rather reduced survival of activated T cells, as transgenic expression of Bcl-xL restored islet allograft rejection in IκBαΔN-Tg mice. Abolishing TCR- and BCR-driven activation of NF-κB selectively via CARMA1 deficiency prevented T cell priming and islet allograft rejection. Conclusions Our data suggest that T cell-NF-κB plays an important role in the rejection of islet allografts. Targeting NF-κB selectively in lymphocytes appears a promising approach to facilitate acceptance of transplanted islets. PMID:22437847

  17. High Fat Diet-induced Obesity Enhances Allograft Rejection

    PubMed Central

    Molinero, Luciana L; Yin, Dengping; Lei, Kevin; Chen, Luqiu; Wang, Ying; Chong, Anita S; Alegre, Maria-Luisa

    2016-01-01

    Background Obesity promotes a state of low-grade inflammation that exacerbates chronic inflammatory diseases such as asthma and inflammatory bowel disease. In transplantation, the survival of organs transplanted into obese patients is reduced compared to allografts in lean recipients. However, whether this is due to increased alloimmunity remains to be addressed conclusively. Methods We used a mouse model of high fat diet (HFD)-induced obesity and assessed immune responses to allogeneic stimulation in vitro, allogeneic splenocyte immunization in vivo, and allogeneic heart transplantation. Results Our results indicate that HFD altered the composition and phenotype of splenic antigen-presenting cells (APCs) that led to their enhanced capacity to stimulate T cells. Immunization with allogeneic splenocytes in vivo resulted in increased alloreactivity, as determined by IFNγ production. Moreover, cardiac allograft rejection in HFD mice was modestly accelerated compared to aged-matched control animals fed a low fat diet (LFD), correlating with enhanced alloreactive T cell function. Conclusions Our results highlight the increased alloresponse triggered by HFD-induced obesity and its negative impact on transplant outcome. PMID:27007226

  18. Solar dynamic heat rejection technology. Task 1: System concept development

    NASA Technical Reports Server (NTRS)

    Gustafson, Eric; Carlson, Albert W.

    1987-01-01

    The results are presented of a concept development study of heat rejection systems for Space Station solar dynamic power systems. The heat rejection concepts are based on recent developments in high thermal transport capacity heat pipe radiators. The thermal performance and weights of each of the heat rejection subsystems is addressed in detail, and critical technologies which require development tests and evaluation for successful demonstration are assessed and identified. Baseline and several alternate heat rejection system configurations and optimum designs are developed for both Brayton and Rankine cycles. The thermal performance, mass properties, assembly requirements, reliability, maintenance requirements and life cycle cost are determined for each configuration. A specific design was then selected for each configuration which represents an optimum design for that configuration. The final recommendations of heat rejection system configuration for either the Brayton or Rankine cycles depend on the priorities established for the evaluation criteria.

  19. Rejection Sensitivity and Adolescents’ Perceptions of Romantic Interactions

    PubMed Central

    Norona, Jerika C.; Salvatore, Joseph F.; Welsh, Deborah P.; Darling, Nancy

    2014-01-01

    Rejection sensitivity – the tendency to expect, perceive, and overreact to rejection by others – is linked with individuals’ expectations that their romantic partners’ behaviors have negative intent, even if, perhaps, such behaviors could be considered neutral when observed by another. The aim of the present study was to test this proposition, derived from rejection sensitivity theory, using a Video-Recall Procedure with adolescent couples in the US (N = 386 adolescents, 50% girls). We examined whether adolescents who were more sensitive to rejection perceived their romantic partners’ behaviors as more conflictual than when viewed by trained, third-party observers. Findings suggest that, at the micro-analytic level, higher rejection sensitivity is associated with adolescents’ heightened perception of their romantic partners as conflictual when compared to observers, who more often coded the same behaviors as neutral rather than conflictual. Implications for adolescent mental health and well-being are discussed. PMID:25282535

  20. Imaging-based diagnosis of acute renal allograft rejection

    PubMed Central

    Thölking, Gerold; Schuette-Nuetgen, Katharina; Kentrup, Dominik; Pawelski, Helga; Reuter, Stefan

    2016-01-01

    Kidney transplantation is the best available treatment for patients with end stage renal disease. Despite the introduction of effective immunosuppressant drugs, episodes of acute allograft rejection still endanger graft survival. Since efficient treatment of acute rejection is available, rapid diagnosis of this reversible graft injury is essential. For diagnosis of rejection, invasive core needle biopsy of the graft is the “gold-standard”. However, biopsy carries the risk of significant graft injury and is not immediately feasible in patients taking anticoagulants. Therefore, a non-invasive tool assessing the whole organ for specific and fast detection of acute allograft rejection is desirable. We herein review current imaging-based state of the art approaches for non-invasive diagnostics of acute renal transplant rejection. We especially focus on new positron emission tomography-based as well as targeted ultrasound-based methods. PMID:27011915

  1. Uptake of myocardial imaging agents by rejected hearts

    SciTech Connect

    Bergsland, J.; Carr, E.A.; Carroll, M.; Wright, J.W.; Feldman, M.J.; Massucci, J.; Bhayana, J.N.; Gona, J.M.

    1985-09-01

    Technetium 99 m pyrophosphate, Gallium 67 and Thallium 201 uptakes were measured in heterotopically transplanted rat hearts. Five days after transplantation, Technetium 99 m pyrophosphate, and Gallium 67 uptakes were significantly higher in allogeneic grafts than in syngeneic grafts. At an early stage of rejection (three days after transplantation), only Technetium 99 m pyrophosphate uptake in the left ventricle of allogeneic grafts showed a significant difference (p less than 0.04). At five days, Thallium 201 uptake was significantly lower in allo- than syngeneic grafts. There was a positive correlation between radionuclide uptake and histologic degree of rejection for Technetium 99 m pyrophosphate and Gallium 67 while Thallium 201 uptake correlated negatively. Analysis of variance revealed that hearts with no or minimal rejection had statistically different uptakes than hearts with mild to moderate rejection. These results suggest that uptake of imaging agents might be useful in the diagnosis of rejection of the transplanted heart.

  2. A rejection method for selection of scattered states

    NASA Astrophysics Data System (ADS)

    Lawson, William S.

    1994-05-01

    A rejection method is presented that sidesteps much of the labor necessary in the usual techniques for choosing a scattered state after an electron-phonon collision with full band structure. The phonon wave number is chosen randomly, then tested to see if the resultant collision will satisfy energy conservation to within some accuracy. If not, the collision is rejected, and if so, then the wave number is adjusted in order to enforce energy conservation more precisely. The price one pays is in a high rejection rate. If the cost of a rejection is small, however, this rejection rate can be tolerated. This method will not compete with analytical models (near valley minima), but may outperform the more usual techniques. Accuracies of a few percent are practical. Simulations were preformed with the first conduction band of gallium arsenide.

  3. Plasma proteolytic activity in liver transplant rejection.

    PubMed

    Scholz, T; Gallimore, M J; Bäckman, L; Mathisen, O; Bergan, A; Klintmalm, G B; Aasen, A O

    1999-01-01

    In this study, we evaluated the role of proteolytic enzymes belonging to the coagulation, fibrinolytic, and plasma contact systems in the early postoperative phase after orthotopic liver transplantation (OLT). Twenty-nine patients were studied at the time of OLT and during the first 2 postoperative weeks. Blood samples were collected daily after OLT and analyzed for kallikrein-like activity (KK), functional kallikrein inhibition (KKI), plasmin-like activity (PL), and alpha2-antiplasmin (AP). In addition, prekallikrein (PKK), prothrombin (PTH), antithrombin III (AT III), plasminogen (PLG), prothrombin/antithrombin III complexes (TAT), prothrombin fragment 1 + 2 (F1 + 2), and plasmin/alpha2-antiplasmin complexes (PAP) were measured. Nineteen patients experienced biopsy-verified acute rejections (AR) and ten patients had uneventful courses and served as controls. Plasma analyses showed that the contact, coagulation, and fibrinolytic systems were activated during OLT. Following OLT, continuous thrombin and plasmin generation was observed, and these effects were more pronounced in the group having an uneventful course than in patients with AR. Factors that could possibly affect plasma proteolytic activity, such as blood product usage during and after OLT and cold ischemia time of the liver graft, did not differ between the groups, nor did the routine liver function tests, alanine aminotransferase (ALT) and aspartate aminotransferase (AST).

  4. Similarity principle and rejection of Gibbs paradox

    NASA Astrophysics Data System (ADS)

    Lin, Shu-Kun

    2000-03-01

    Gibbs Paradox says that entropy of mixing or assembling decreases discotinuously with the increase in the property similarity. After the rejection of the Gibbs paradox statement (see papers cited at website http://www.mdpi.org/lin/), the similarity principle has been developed: If all the other conditions remain constant, the higher the similarity among the components is, the higher value of entropy of the mixing, the assembling or the chemical bond formation process will be, the more spontaneous the mixing, the assembling or the chemical bond formation process will be, and the more stable the mixture, the assemblage or the chemical bond will be. The similarity principle is very useful. If one wants to mix substances, increase the similarity (of relevant properties); if one plans to separate the substances as phases, reduce their similarity! Then, the desirable processes of mixing or separation will happen spontaneously. Normally by changing temperature ( similarity is related to Boltzmann factor) and pressure, one can control the similarity and in turn, direct the process towards the desired direction. Higher temperature and pressure leads to higher similarity. This theory is important in understanding molecular recognition, self-organization, molecular assembling and molecular replication.

  5. South African court rejects country's new constitution.

    PubMed

    1996-09-20

    Fundamental principles designed to ensure that South Africa's new constitution upholds a wide range of individual rights and freedoms and establishes a responsive government with a balanced separation of powers, including recognition of the role of traditional tribal leadership, were adopted into the current interim constitution shortly before the 1994 free elections which brought Nelson Mandela and the African National Congress to power. In a judgement issued on September 6, 1996, South Africa's Constitutional Court rejected the country's new draft constitution, arguing that it failed to meet the standards of nine of the 34 principles established at the Kempton Park negotiations. The Constitutional Assembly is comprised of a joint meeting of the National Assembly and Senate. One of the court's major objections to the constitution concerned the proposed structure of rule, which was seen to give inadequate power to South Africa's nine provinces as compared with the national government. However, the bill of rights was almost entirely upheld. The bill would create a favorable environment for legalized abortion and guarantee a universal right of access to health care, including reproductive health services

  6. Compton rejection for HPGe detectors via real-time pulse shape analysis

    SciTech Connect

    Beckedahl, D; Blair, J J; Friensehner, A; Kammeraad, J E; Kreek, S A; Payne, B; Schmid, G J

    1998-07-31

    A Lawrence Livermore National Laboratory-developed pulse shape analysis (PSA) technique which performs real-time Compton suppression in High Purity Germanium (HPGe) detectors without the use of anti-coincidence detectors is described. Some preliminary measurements of a variety of sources with a standard HPGe detector system and our prototype PSA algorithm have been made and indicate that a reduction in Compton continuum can be achieved via PSA. These measurements represent an initial assessment of the effectiveness of the prototype PSA system for the improvement of spectral quality and future improvements are expected. Additional work is progressing to optimize the effectiveness of the algorithm for Compton rejection in standard HPGe detectors. Work is also progressing to extend the methodology to segmented HPGe detectors which could potentially yield significantly better Compton rejection and gamma-ray ima

  7. Rejection of micropollutants by clean and fouled forward osmosis membrane.

    PubMed

    Valladares Linares, Rodrigo; Yangali-Quintanilla, Victor; Li, Zhenyu; Amy, Gary

    2011-12-15

    As forward osmosis (FO) gains attention as an efficient technology to improve wastewater reclamation processes, it is fundamental to determine the influence of fouling in the rejection of emerging contaminants (micropollutants). This study focuses on the rejection of 13 selected micropollutants, spiked in a secondary wastewater effluent, by a FO membrane, using Red Sea water as draw solution (DS), differentiating the effects on the rejection caused by a clean and fouled membrane. The resulting effluent was then desalinated at low pressure with a reverse osmosis (RO) membrane, to produce a high quality permeate and determine the rejection with a coupled forward osmosis - low pressure reverse osmosis (FO-LPRO) system. When considering only FO with a clean membrane, the rejection of the hydrophilic neutral compounds was between 48.6% and 84.7%, for the hydrophobic neutrals the rejection ranged from 40.0% to 87.5%, and for the ionic compounds the rejections were between 92.9% and 96.5%. With a fouled membrane, the rejections were between 44.6% and 95.2%, 48.7%-91.5% and 96.9%-98.6%, respectively. These results suggest that, except for the hydrophilic neutral compounds, the rejection of the micropollutants is increased by the presence of a fouling layer, possibly due to the higher hydrophilicity of the FO fouled membrane compared to the clean one, the increased adsorption capacity of hydrophilic compounds and reduced mass transport capacity, membrane swelling, and the higher negative charge of the membrane surface, related to the foulants composition, mainly NOM acids (carboxylic radicals) and polysaccharides or polysaccharide-like substances. However, when coupled with RO, the rejections in both cases increased above 96%. The coupled FO-LPRO system was an effective double barrier against the selected micropollutants. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Specimen rejection in laboratory medicine: Necessary for patient safety?

    PubMed

    Dikmen, Zeliha Gunnur; Pinar, Asli; Akbiyik, Filiz

    2015-01-01

    The emergency laboratory in Hacettepe University Hospitals receives specimens from emergency departments (EDs), inpatient services and intensive care units (ICUs). The samples are accepted according to the rejection criteria of the laboratory. In this study, we aimed to evaluate the sample rejection ratios according to the types of pre-preanalytical errors and collection areas. The samples sent to the emergency laboratory were recorded during 12 months between January to December, 2013 in which 453,171 samples were received and 27,067 specimens were rejected. Rejection ratios was 2.5% for biochemistry tests, 3.2% for complete blood count (CBC), 9.8% for blood gases, 9.2% for urine analysis, 13.3% for coagulation tests, 12.8% for therapeutic drug monitoring, 3.5% for cardiac markers and 12% for hormone tests. The most frequent rejection reasons were fibrin clots (28%) and inadequate volume (9%) for biochemical tests. Clotted samples (35%) and inadequate volume (13%) were the major causes for coagulation tests, blood gas analyses and CBC. The ratio of rejected specimens was higher in the EDs (40%) compared to ICUs (30%) and inpatient services (28%). The highest rejection ratio was observed in neurology ICU (14%) among the ICUs and internal medicine inpatient service (10%) within inpatient clinics. We detected an overall specimen rejection rate of 6% in emergency laboratory. By documentation of rejected samples and periodic training of healthcare personnel, we expect to decrease sample rejection ratios below 2%, improve total quality management of the emergency laboratory and promote patient safety.

  9. Specimen rejection in laboratory medicine: Necessary for patient safety?

    PubMed Central

    Dikmen, Zeliha Gunnur; Pinar, Asli; Akbiyik, Filiz

    2015-01-01

    Introduction The emergency laboratory in Hacettepe University Hospitals receives specimens from emergency departments (EDs), inpatient services and intensive care units (ICUs). The samples are accepted according to the rejection criteria of the laboratory. In this study, we aimed to evaluate the sample rejection ratios according to the types of pre-preanalytical errors and collection areas. Materials and methods The samples sent to the emergency laboratory were recorded during 12 months between January to December, 2013 in which 453,171 samples were received and 27,067 specimens were rejected. Results Rejection ratios was 2.5% for biochemistry tests, 3.2% for complete blood count (CBC), 9.8% for blood gases, 9.2% for urine analysis, 13.3% for coagulation tests, 12.8% for therapeutic drug monitoring, 3.5% for cardiac markers and 12% for hormone tests. The most frequent rejection reasons were fibrin clots (28%) and inadequate volume (9%) for biochemical tests. Clotted samples (35%) and inadequate volume (13%) were the major causes for coagulation tests, blood gas analyses and CBC. The ratio of rejected specimens was higher in the EDs (40%) compared to ICUs (30%) and inpatient services (28%). The highest rejection ratio was observed in neurology ICU (14%) among the ICUs and internal medicine inpatient service (10%) within inpatient clinics. Conclusions We detected an overall specimen rejection rate of 6% in emergency laboratory. By documentation of rejected samples and periodic training of healthcare personnel, we expect to decrease sample rejection ratios below 2%, improve total quality management of the emergency laboratory and promote patient safety. PMID:26527231

  10. Fabrication of Silicon Backshorts with Improved Out-of-Band Rejection for Waveguide-Coupled Superconducting Detectors

    NASA Technical Reports Server (NTRS)

    Crowe, Erik J.; Bennett, Charles L.; Chuss, David T.; Denis, Kevin L.; Eimer, Joseph; Lourie, Nathan; Marriage, Tobias; Moseley, Samuel H.; Rostem, Karwan; Stevenson, Thomas R.; hide

    2012-01-01

    The Cosmology Large Angular Scale Surveyor (CLASS) is a ground-based instrument that will measure the polarization of the cosmic microqave background to search for gravitational waves form a posited epoch of inflation early in the universe's history. This measurement will require integration of superconducting transition-edge sensors with microwave waveguide inputs with good conrol of systematic errors, such as unwanted coupling to stray signals at frequencies outside of a precisely defined microwave band. To address these needs we will present work on the fabrication of silicon quarter-wave backshorts for the CLASS 40GHz focal plane. The 40GHz backshort consists of three degeneratively doped silicon wafers. Two spacer wafers are micromachined with through wafer vins to provide a 2.0mm long square waveguide. The third wafer acts as the backshort cap. The three wafers are bonded at the wafer level by Au-Au thermal compression bonding then aligned and flip chip bonded to the CLASS detector at the chip level. The micromachining techniques used have been optimized to create high aspect ratio waveguides, silicon pillars, and relief trenches with the goal of providing improved out of band signal rejection. We will discuss the fabrication of integrated CLASS superconducting detectors with silicon quarter wave backshorts and present current measurement results.

  11. Background reduction in the SNO+ experiment

    SciTech Connect

    Segui, L.

    2015-08-17

    SNO+ is a large multi-purpose liquid scintillator experiment, which first aim is to detect the neutrinoless double beta decay of {sup 130}Te. It is placed at SNOLAB, at 6000 m.w.e. and it is based on the SNO infrastructure. SNO+ will contain approximately 780 tonnes of liquid scintillator, loaded with {sup 130}Te inside an acrylic vessel (AV) with an external volume of ultra pure water to reduce the external backgrounds. Light produced in the scintillator by the interaction of particles will be detected with about 9,000 photomultiplier’s. For the neutrinoless double beta decay phase, due to its the extremely low rate expected, the control, knowledge and reduction of the background is essential. Moreover, it will also benefit other phases of the experiment focused on the study of solar neutrinos, nucleon decay, geoneutrinos and supernovae. In order to reduce the internal background level, a novel purification technique for tellurium loaded scintillators has been developed by the collaboration that reduces the U/Th concentration and several cosmic-activated isotopes by at least a factor 10{sup 2} -10{sup 3} in a single pass. In addition, different rejection techniques have been developed for the remaining internal backgrounds based on Monte-Carlo simulations. In this work, the scintillator purification technique and the levels obtained with it will be discussed. Furthermore, an overview of the different backgrounds for the double-beta phase will be presented, highlighting some of the techniques developed to reject the remained decays based on their expected timing differences.

  12. Some applications of Photon/Electron-Rejecting Alpha Liquid Scintillation (PERALS) spectrometry to the assay of alpha emitters

    SciTech Connect

    McDowell, W.J.; Case, G.N.

    1988-01-01

    The combination of certain solvent extraction separations and a special kind of liquid scintillation detector and electronics designed for alpha spectrometry allows some highly accurate, yet simple determinations of alpha-emitting nuclides. Counting efficiency is 99.68% with backgrounds of <0.02 cpm. Energy resolution and peak position are sufficient for the identification of many nuclides. Rejection of interference from ..beta.. and ..gamma.. radiation is >99.95%. The Photon/Electron Rejecting Alpha Liquid Scintillation (PERALS) equipment is described and procedures for the separation and determination of uranium, thorium, plutonium, polonium, radium, and trivalent actinides are outlined. 25 refs., 10 figs., 1 tab.

  13. 21 CFR 111.170 - What requirements apply to rejected components, packaging, and labels, and to rejected products...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 2 2013-04-01 2013-04-01 false What requirements apply to rejected components, packaging, and labels, and to rejected products that are received for packaging or labeling as a dietary supplement? 111.170 Section 111.170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH...

  14. 21 CFR 111.170 - What requirements apply to rejected components, packaging, and labels, and to rejected products...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 2 2014-04-01 2014-04-01 false What requirements apply to rejected components, packaging, and labels, and to rejected products that are received for packaging or labeling as a dietary supplement? 111.170 Section 111.170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH...

  15. 21 CFR 111.170 - What requirements apply to rejected components, packaging, and labels, and to rejected products...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 2 2012-04-01 2012-04-01 false What requirements apply to rejected components, packaging, and labels, and to rejected products that are received for packaging or labeling as a dietary supplement? 111.170 Section 111.170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH...

  16. Trait rejection sensitivity is associated with vigilance and defensive response rather than detection of social rejection cues

    PubMed Central

    Kawamoto, Taishi; Nittono, Hiroshi; Ura, Mitsuhiro

    2015-01-01

    Prior studies suggest that psychological difficulties arise from higher trait Rejection Sensitivity (RS)—heightened vigilance and differential detection of social rejection cues and defensive response to. On the other hand, from an evolutionary perspective, rapid and efficient detection of social rejection cues can be considered beneficial. We conducted a survey and an electrophysiological experiment to reconcile this seeming contradiction. We compared the effects of RS and Rejection Detection Capability (RDC) on perceived interpersonal experiences (Study 1) and on neurocognitive processes in response to cues of social rejection (disgusted faces; Study 2). We found that RS and RDC were not significantly related, although RS was positively related to perceived social rejection experiences and RDC was positively related to perceived social inclusion experiences. Event-related brain potentials (ERPs) revealed that higher RS was related to cognitive avoidance (i.e., P1) and heightened motivated attention (i.e., late positive potential: LPP), but not to facial expression encoding (i.e., N170) toward disgusted faces. On the other hand, higher RDC was related to heightened N170 amplitude, but not to P1 and LPP amplitudes. These findings imply that sensitivity to rejection is apparently distinct from the ability to detect social rejection cues and instead reflects intense vigilance and defensive response to those cues. We discussed an alternative explanation of the relationship between RS and RDC from a signal detection perspective. PMID:26483750

  17. Rejected by peers-attracted to antisocial media content: rejection-based anger impairs moral judgment among adolescents.

    PubMed

    Plaisier, Xanthe S; Konijn, Elly A

    2013-06-01

    Adolescence is an important developmental stage during which both peers and the media have a strong influence. Both peer rejection and the use of morally adverse media are associated with negative developmental outcomes. This study examines processes by which peer rejection might drive adolescents to select antisocial media content by tying together developmental research on peer rejection and research on media effects. Assumed underlying mechanisms are rejection-based anger and frustration and the adolescent's moral judgment. A between-participants experimental design manipulated peer rejection versus acceptance in adolescents (Mage = 13.88 years; N = 74) and young adults (Mage = 21.37 years; N = 75), applying the Cyberball paradigm. Measures included the State Anger Inventory (STAXI) to assess feelings of rejection and the newly devised Media, Morals, and Youth Questionnaire (MMaYQue) to assess media preferences and moral judgment of media content. Using bootstrapping analyses, a double mediation was established: Higher levels of state anger in peer-rejected adolescents induced more tolerable moral judgments of antisocial media content, subsequently instigating a preference for antisocial media content. In contrast, the young adult sample showed no relations between peer rejection and antisocial media preference. Results are discussed within a downward spiral framework of combined peer and media influences.

  18. Rejected by Peers--Attracted to Antisocial Media Content: Rejection-Based Anger Impairs Moral Judgment among Adolescents

    ERIC Educational Resources Information Center

    Plaisier, Xanthe S.; Konijn, Elly A.

    2013-01-01

    Adolescence is an important developmental stage during which both peers and the media have a strong influence. Both peer rejection and the use of morally adverse media are associated with negative developmental outcomes. This study examines processes by which peer rejection might drive adolescents to select antisocial media content by tying…

  19. Rejected by Peers--Attracted to Antisocial Media Content: Rejection-Based Anger Impairs Moral Judgment among Adolescents

    ERIC Educational Resources Information Center

    Plaisier, Xanthe S.; Konijn, Elly A.

    2013-01-01

    Adolescence is an important developmental stage during which both peers and the media have a strong influence. Both peer rejection and the use of morally adverse media are associated with negative developmental outcomes. This study examines processes by which peer rejection might drive adolescents to select antisocial media content by tying…

  20. New Methods for Noninvasive Monitoring of Rejection after Heart Transplantation

    PubMed Central

    Reichenspumer, Hermann; Haberl, Ralph; Angermann, Christiane; Anthuber, Matthias; Osterholzer, Georg; Kemkes, Bemhard M.; Hammer, Claus; Gokel, Joachim M.; Reichart, Bruno

    1988-01-01

    Between August 1981 and February 1987, 67 orthotopic heart transplants and three heart-lung transplants were performed in 69 patients at the University of Munich Hospital. The immunosuppressive regimen consisted of cyclosporine A, azathioprine, and prednisone. The diagnosis of acute rejection was based on cytoimmunologic monitoring, frequency analysis of fast Fourier transformed surface electrocardiograms (FFT-ECGs), and two-dimensional echocardiography. The results of these diagnostic methods were compared to the findings provided by endomyocardial biopsies, which were performed simultaneously with the noninvasive studies. Seventy patients underwent cytoimmunologic monitoring. In 88% of all rejection episodes, this technique revealed activated lymphocytes and lymphoblasts in the mononuclear concentrate of the peripheral blood samples; the presence of such cells is known to be an extremely early sign of acute rejection. Twenty-six patients were monitored by means of FFT-ECG. In 20 of the 21 cases of rejection, this method disclosed significant changes in the frequency spectrum of the QRS complex in the 70- to 110-Hz range; in 12 cases, these changes were the earliest sign of acute rejection. Therefore, FFT-ECG had a sensitivity of 95%. All of the QRS changes were reversible with rejection therapy. Forty-five patients were subjected to two-dimensional echocardiography. In 31 of the 35 cases of rejection, the echocardiogram showed a significant increase in the left ventricular wall thickness and a decrease in the left ventricular cross-sectional area during mild rejection. Moderate or severe rejection was characterized by an increase in the diastolic area, as well as a decrease in the systolic area change and in the diastolic maximum velocity of area change. Thus, two-dimensional echocardiography had a sensitivity of 89%. In the recent cases, the diagnosis of rejection was based on noninvasive methods alone. After rejection therapy had been instituted, endomyocardial

  1. Development of CDMS-II Surface Event Rejection Techniques and Their Extensions to Lower Energy Thresholds

    SciTech Connect

    Hofer, Thomas James

    2014-12-01

    The CDMS-II phase of the Cryogenic Dark Matter Search, a dark matter direct-detection experiment, was operated at the Soudan Underground Laboratory from 2003 to 2008. The full payload consisted of 30 ZIP detectors, totaling approximately 1.1 kg of Si and 4.8 kg of Ge, operated at temperatures of 50 mK. The ZIP detectors read out both ionization and phonon pulses from scatters within the crystals; channel segmentation and analysis of pulse timing parameters allowed e ective ducialization of the crystal volumes and background rejection su cient to set world-leading limits at the times of their publications. A full re-analysis of the CDMS-II data was motivated by an improvement in the event reconstruction algorithms which improved the resolution of ionization energy and timing information. The Ge data were re-analyzed using three distinct background-rejection techniques; the Si data from runs 125 - 128 were analyzed for the rst time using the most successful of the techniques from the Ge re-analysis. The results of these analyses prompted a novel \\mid-threshold" analysis, wherein energy thresholds were lowered but background rejection using phonon timing information was still maintained. This technique proved to have signi cant discrimination power, maintaining adequate signal acceptance and minimizing background leakage. The primary background for CDMS-II analyses comes from surface events, whose poor ionization collection make them di cult to distinguish from true nuclear recoil events. The novel detector technology of SuperCDMS, the successor to CDMS-II, uses interleaved electrodes to achieve full ionization collection for events occurring at the top and bottom detector surfaces. This, along with dual-sided ionization and phonon instrumentation, allows for excellent ducialization and relegates the surface-event rejection techniques of CDMS-II to a secondary level of background discrimination. Current and future SuperCDMS results hold great promise for mid- to low

  2. Background sources at PEP

    SciTech Connect

    Lynch, H.; Schwitters, R.F.; Toner, W.T.

    1988-01-01

    Important sources of background for PEP experiments are studied. Background particles originate from high-energy electrons and positrons which have been lost from stable orbits, ..gamma..-rays emitted by the primary beams through bremsstrahlung in the residual gas, and synchrotron radiation x-rays. The effect of these processes on the beam lifetime are calculated and estimates of background rates at the interaction region are given. Recommendations for the PEP design, aimed at minimizing background are presented. 7 figs., 4 tabs.

  3. Rejection versus escape: the tumor MHC dilemma.

    PubMed

    Garrido, Federico; Ruiz-Cabello, Francisco; Aptsiauri, Natalia

    2017-02-01

    Most tumor cells derive from MHC-I-positive normal counterparts and remain positive at early stages of tumor development. T lymphocytes can infiltrate tumor tissue, recognize and destroy MHC class I (MHC-I)-positive cancer cells ("permissive" phase I). Later, MHC-I-negative tumor cell variants resistant to T-cell killing emerge. During this process, tumors first acquire a heterogeneous MHC-I expression pattern and finally become uniformly MHC-I-negative. This stage (phase II) represents a "non-permissive" encapsulated structure with tumor nodes surrounded by fibrous tissue containing different elements including leukocytes, macrophages, fibroblasts, etc. Molecular mechanisms responsible for total or partial MHC-I downregulation play a crucial role in determining and predicting the antigen-presenting capacity of cancer cells. MHC-I downregulation caused by reversible ("soft") lesions can be upregulated by TH1-type cytokines released into the tumor microenvironment in response to different types of immunotherapy. In contrast, when the molecular mechanism of the tumor MHC-I loss is irreversible ("hard") due to a genetic defect in the gene/s coding for MHC-I heavy chains (chromosome 6) or beta-2-microglobulin (B2M) (chromosome 15), malignant cells are unable to upregulate MHC-I, remain undetectable by cytotoxic T-cells, and continue to grow and metastasize. Based on the tumor MHC-I molecular analysis, it might be possible to define MHC-I phenotypes present in cancer patients in order to distinguish between non-responders, partial/short-term responders, and likely durable responders. This highlights the need for designing strategies to enhance tumor MHC-I expression that would allow CTL-mediated tumor rejection.

  4. Separate neural representations for physical pain and social rejection

    PubMed Central

    Woo, Choong-Wan; Koban, Leonie; Kross, Ethan; Lindquist, Martin A.; Banich, Marie T.; Ruzic, Luka; Andrews-Hanna, Jessica R.; Wager, Tor D.

    2014-01-01

    Current theories suggest that physical pain and social rejection share common neural mechanisms, largely by virtue of overlapping functional magnetic resonance imaging (fMRI) activity. Here we challenge this notion by identifying distinct multivariate fMRI patterns unique to pain and rejection. Sixty participants experience painful heat and warmth and view photos of ex-partners and friends on separate trials. FMRI pattern classifiers discriminate pain and rejection from their respective control conditions in out-of-sample individuals with 92% and 80% accuracy. The rejection classifier performs at chance on pain, and vice versa. Pain-and rejection-related representations are uncorrelated within regions thought to encode pain affect (for example, dorsal anterior cingulate) and show distinct functional connectivity with other regions in a separate resting-state data set (N = 91). These findings demonstrate that separate representations underlie pain and rejection despite common fMRI activity at the gross anatomical level. Rather than co-opting pain circuitry, rejection involves distinct affective representations in humans. PMID:25400102

  5. Lunar Dust on Heat Rejection System Surfaces: Problems and Prospects

    NASA Technical Reports Server (NTRS)

    Gaier, James R.; Jaworske, Donald A.

    2007-01-01

    Heat rejection from power systems will be necessary for human and robotic activity on the lunar surface. Functional operation of such heat rejection systems is at risk of degradation as a consequence of dust accumulation. The Apollo astronauts encountered marked degradation of performance in heat rejection systems for the lunar roving vehicle, science packages, and other components. Although ground testing of dust mitigation concepts in support of the Apollo mission identified mitigation tools, the brush concept adopted by the Apollo astronauts proved essentially ineffective. A better understanding of the issues associated with the impact of lunar dust on the functional performance of heat rejection systems and its removal is needed as planning gets underway for human and robotic missions to the Moon. Renewed emphasis must also be placed on ground testing of pristine and dust-covered heat rejection system surfaces to quantify degradation and address mitigation concepts. This paper presents a review of the degradation in performance of heat rejection systems encountered on the lunar surface to-date, and will discuss current activities underway to evaluate the durability of candidate heat rejection system surfaces and current dust mitigation concepts.

  6. Early diagnosis of acute postoperative renal transplant rejection

    SciTech Connect

    Tisdale, P.L.; Collier, B.D.; Kauffman, H.M.; Adams, M.B.; Isitman, A.T.; Hellman, R.S.; Rao, S.A.; Joestgen, T.; Krohn, L.

    1985-05-01

    A prospective evaluation of In-111 labeled autologous platelet scintigraphy for the early diagnosis of acute postoperative renal transplant rejection was undertaken. To date, 28 consecutive patients between 7 and 14 days post-op have been injected with 500..mu..Ci of In-111 platelets followed by imaging at 24 and 48 hours. Activity within the renal transplant exceeding activity in the adjacent iliac vessels was considered to be evidence of rejection, and both chemical evidence and clinical impression of rejection at 5 days after completion of imaging was accepted as proof of ongoing or incipient rejection at the time of scintigraphy. In addition, to visual inspection, independent quantitative analysis compared the area-normalized activity over the transplant with the adjacent iliac vessels (normal <1.0). For 5 patients, positive In-111 scintigraphy was present before convincing clinical evidence of rejection. In-111 platelet scintigraphy is useful not only to confirm the clinical diagnosis of rejection but also to establish the early, pre-clinical diagnosis of incipient acute postoperative renal transplant rejection.

  7. Separate neural representations for physical pain and social rejection.

    PubMed

    Woo, Choong-Wan; Koban, Leonie; Kross, Ethan; Lindquist, Martin A; Banich, Marie T; Ruzic, Luka; Andrews-Hanna, Jessica R; Wager, Tor D

    2014-11-17

    Current theories suggest that physical pain and social rejection share common neural mechanisms, largely by virtue of overlapping functional magnetic resonance imaging (fMRI) activity. Here we challenge this notion by identifying distinct multivariate fMRI patterns unique to pain and rejection. Sixty participants experience painful heat and warmth and view photos of ex-partners and friends on separate trials. FMRI pattern classifiers discriminate pain and rejection from their respective control conditions in out-of-sample individuals with 92% and 80% accuracy. The rejection classifier performs at chance on pain, and vice versa. Pain- and rejection-related representations are uncorrelated within regions thought to encode pain affect (for example, dorsal anterior cingulate) and show distinct functional connectivity with other regions in a separate resting-state data set (N = 91). These findings demonstrate that separate representations underlie pain and rejection despite common fMRI activity at the gross anatomical level. Rather than co-opting pain circuitry, rejection involves distinct affective representations in humans.

  8. Detection of cardiac transplant rejection with radiolabeled lymphocytes. [Rats

    SciTech Connect

    Bergmann, S.R.; Lerch, R.A.; Carlson, E.M.; Saffitz, J.E.; Sobel, B.E.

    1982-03-01

    To determine whether rejections of cardiac transplants could be detected specifically and non-invasively by lymphocytes labeled with indium-111 (111In), we studied 36 allogeneic and 14 isogeneic heterotopic cardiac transplants in rats. Allogeneic grafts accumulated autologous 111In-lymphocytes, detectable scintigraphically 24 hours after i.v. injection of the labeled cells. At the time of peak histologic rejection, the allogeneic grafts accumulated 92. +/- 4.8 times more activity than the native hearts (determined by well counting). The tissue-to-blood ratio in the rejecting transplants was 3.7 +/- 2.2; total uptake by the graft was 2.9 +/- 2.1% of the injected dose. Autoradiography confirmed that graft radioactivity was associated with labeled lymphocytes. In contrast, isogeneic grafts showed no signs of rejection and did not accumulate radioactivity. Because conventionally isolated and labeled lymphocytes are often contaminated with platelets, we prepared both 111In-platelets and purified 111In-lymphocytes for use in additional experiments. Allogeneic grafts accumulated platelets and purified lymphocytes independently. Thus, deposition of immunologically active cells in the rejecting graft representing specific pathophysiologic events can be detected. The results suggest that rejection of cardiac transplants can be detected noninvasively, potentially facilitating objective early clinical detection of rejection and titration of antirejection therapy.

  9. Lunar Dust on Heat Rejection System Surfaces: Problems and Prospects

    NASA Astrophysics Data System (ADS)

    Gaier, James R.; Jaworske, Donald A.

    2007-01-01

    Heat rejection from power systems will be necessary for human and robotic activity on the lunar surface. Functional operation of such heat rejection systems is at risk of degradation as a consequence of dust accumulation. The Apollo astronauts encountered marked degradation of performance in heat rejection systems for the lunar roving vehicle, science packages, and other components. Although ground testing of dust mitigation concepts in support of the Apollo mission identified candidate mitigation tools, the brush concept adopted by the Apollo astronauts proved essentially ineffective. A better understanding of the issues associated with the impact of lunar dust on the functional performance of heat rejection systems and its removal is needed as planning gets underway for human and robotic missions to the Moon. Renewed emphasis must also be placed on ground testing of pristine and dust-covered heat rejection system surfaces to quantify degradation and address mitigation concepts. This paper presents a review of the degradation of heat rejection systems encountered on the lunar surface to-date, and discusses current activities underway to evaluate the durability of candidate heat rejection system surfaces and current dust mitigation concepts.

  10. A computational assessment of the permeability and salt rejection of carbon nanotube membranes and their application to water desalination

    PubMed Central

    Thomas, Michael; Corry, Ben

    2016-01-01

    Membranes made from nanomaterials such as nanotubes and graphene have been suggested to have a range of applications in water filtration and desalination, but determining their suitability for these purposes requires an accurate assessment of the properties of these novel materials. In this study, we use molecular dynamics simulations to determine the permeability and salt rejection capabilities for membranes incorporating carbon nanotubes (CNTs) at a range of pore sizes, pressures and concentrations. We include the influence of osmotic gradients and concentration build up and simulate at realistic pressures to improve the reliability of estimated membrane transport properties. We find that salt rejection is highly dependent on the applied hydrostatic pressure, meaning high rejection can be achieved with wider tubes than previously thought; while membrane permeability depends on salt concentration. The ideal size of the CNTs for desalination applications yielding high permeability and high salt rejection is found to be around 1.1 nm diameter. While there are limited energy gains to be achieved in using ultra-permeable CNT membranes in desalination by reverse osmosis, such membranes may allow for smaller plants to be built as is required when size or weight must be minimized. There are diminishing returns in further increasing membrane permeability, so efforts should focus on the fabrication of membranes containing narrow or functionalized CNTs that yield the desired rejection or selection properties rather than trying to optimize pore densities. PMID:26712639

  11. A computational assessment of the permeability and salt rejection of carbon nanotube membranes and their application to water desalination.

    PubMed

    Thomas, Michael; Corry, Ben

    2016-02-13

    Membranes made from nanomaterials such as nanotubes and graphene have been suggested to have a range of applications in water filtration and desalination, but determining their suitability for these purposes requires an accurate assessment of the properties of these novel materials. In this study, we use molecular dynamics simulations to determine the permeability and salt rejection capabilities for membranes incorporating carbon nanotubes (CNTs) at a range of pore sizes, pressures and concentrations. We include the influence of osmotic gradients and concentration build up and simulate at realistic pressures to improve the reliability of estimated membrane transport properties. We find that salt rejection is highly dependent on the applied hydrostatic pressure, meaning high rejection can be achieved with wider tubes than previously thought; while membrane permeability depends on salt concentration. The ideal size of the CNTs for desalination applications yielding high permeability and high salt rejection is found to be around 1.1 nm diameter. While there are limited energy gains to be achieved in using ultra-permeable CNT membranes in desalination by reverse osmosis, such membranes may allow for smaller plants to be built as is required when size or weight must be minimized. There are diminishing returns in further increasing membrane permeability, so efforts should focus on the fabrication of membranes containing narrow or functionalized CNTs that yield the desired rejection or selection properties rather than trying to optimize pore densities.

  12. Adenovirus Interstitial Nephritis and Rejection in an Allograft

    PubMed Central

    Storsley, Leroy

    2011-01-01

    Viral infections are an important complication of solid organ transplantation. Although polyoma is the virus that most commonly infects the renal allograft, adenoviral infections are also reported. We describe the clinical and pathologic findings in a patient with adenoviral infection associated with acute rejection of the renal allograft. The pathologic findings of adenovirus infection usually include a granulomatous interstitial nephritis, which is helpful in distinguishing from acute rejection. We discuss the differential diagnosis and pathophysiology of allograft viral infections and concomitant rejection. PMID:21436288

  13. Perceived mother and father acceptance-rejection predict four unique aspects of child adjustment across nine countries

    PubMed Central

    Putnick, Diane L.; Bornstein, Marc H.; Lansford, Jennifer E.; Malone, Patrick S.; Pastorelli, Concetta; Skinner, Ann T.; Sorbring, Emma; Tapanya, Sombat; Tirado, Liliana Maria Uribe; Zelli, Arnaldo; Alampay, Liane Peña; Al-Hassan, Suha M.; Bacchini, Dario; Bombi, Anna Silvia; Chang, Lei; Deater-Deckard, Kirby; Di Giunta, Laura; Dodge, Kenneth A.; Oburu, Paul

    2014-01-01

    Background It is generally believed that parental rejection of children leads to child maladaptation. However, the specific effects of perceived parental acceptance-rejection on diverse domains of child adjustment and development have been incompletely documented, and whether these effects hold across diverse populations and for mothers and fathers are still open questions. Methods This study assessed children's perceptions of mother and father acceptance-rejection in 1247 families from China, Colombia, Italy, Jordan, Kenya, the Philippines, Sweden, Thailand, and the United States as antecedent predictors of later internalizing and externalizing behavior problems, school performance, prosocial behavior, and social competence. Results Higher perceived parental rejection predicted increases in internalizing and externalizing behavior problems and decreases in school performance and prosocial behavior across three years controlling for within-wave relations, stability across waves, and parental age, education, and social desirability bias. Patterns of relations were similar across mothers and fathers and, with a few exceptions, all 9 countries. Conclusions Children's perceptions of maternal and paternal acceptance-rejection have small but nearly universal effects on multiple aspects of their adjustment and development regardless of the family's country of origin. PMID:25492267

  14. Long-Term Tolerance to Kidney Allografts after Induced Rejection of Donor Hematopoietic Chimerism in a Preclinical Canine Model

    PubMed Central

    Graves, Scott S.; Mathes, David W.; Georges, George E.; Kuhr, Christian S.; Chang, Jeff; Butts, Tiffany M.; Storb, Rainer

    2012-01-01

    Background Allogeneic hematopoietic cell transplantation provides a reliable method for inducing tolerance towards solid organ grafts. However, this procedure can result in graft-versus-host disease (GVHD) thereby limiting its application. Here we test the hypothesis that mixed chimerism can be intentionally reverted to host hematopoiesis without rejection of a kidney graft. Methods Recipient dogs were given 2 Gy total body irradiation (TBI) before and a short course of immunosuppression after marrow infusion from dog leukocyte antigen-identical littermates. All dogs achieved stable mixed chimerism. After a mean of 20 weeks, one cohort of dogs received kidney transplants from their respective marrow donors. Subsequently, recipients were reconditioned with 2 Gy TBI and given autologous granulocyte-colony stimulating factor-mobilized leukocytes (recipient leukocyte infusion) that had been collected before marrow transplant. Results Dogs receiving a second TBI and recipient leukocyte infusion without a kidney transplant rejected their donor hematopoietic graft within 3 weeks. Dogs that received kidney grafts, followed by a second TBI and recipient leukocyte infusion, rejected their marrow graft without rejecting their transplanted kidneys for periods greater than one year. Conclusion Mixed chimerism may be clinically reverted to 100% recipient without rejection of a kidney allograft. This finding may have application towards minimizing the risk of GVHD in solid organ transplant patients given hematopoietic cell transplantation from HLA-identical donors. PMID:22929594

  15. Recovery and recycling of uranium from rejected coated particles for compact high temperature reactors

    NASA Astrophysics Data System (ADS)

    Pai, Rajesh V.; Mollick, P. K.; Kumar, Ashok; Banerjee, J.; Radhakrishna, J.; Chakravartty, J. K.

    2016-05-01

    UO2 microspheres prepared by internal gelation technique were coated with pyrolytic carbon and silicon carbide using CVD technique. The particles which were not meeting the specifications were rejected. The rejected/failed UO2 based coated particles prepared by CVD technique was used for oxidation and recovery and recycling. The oxidation behaviour of sintered UO2 microspheres coated with different layers of carbon and SiC was studied by thermal techniques to develop a method for recycling and recovery of uranium from the failed/rejected coated particles. It was observed that the complete removal of outer carbon from the spheres is difficult. The crushing of microspheres enabled easier accessibility of oxygen and oxidation of carbon and uranium at 800-1000 °C. With the optimized process of multiple crushing using die & plunger and sieving the broken coated layers, we could recycle around fifty percent of the UO2 microspheres which could be directly recoated. The rest of the particles were recycled using a wet recycling method.

  16. Automatic detection of regional heart rejection in USPIO-enhanced MRI.

    PubMed

    Chang, Hsun-Hsien; Moura, José M F; Wu, Yijen L; Ho, Chien

    2008-08-01

    Contrast-enhanced magnetic resonance imaging (MRI) is useful to study the infiltration of cells in vivo. This research adopts ultrasmall superparamagnetic iron oxide (USPIO) particles as contrast agents. USPIO particles administered intravenously can be endocytosed by circulating immune cells, in particular, macrophages. Hence, macrophages are labeled with USPIO particles. When a transplanted heart undergoes rejection, immune cells will infiltrate the allograft. Imaged by T(2)(*)-weighted MRI, USPIO-labeled macrophages display dark pixel intensities. Detecting these labeled cells in the image facilitates the identification of acute heart rejection. This paper develops a classifier to detect the presence of USPIO-labeled macrophages in the myocardium in the framework of spectral graph theory. First, we describe a USPIO-enhanced heart image with a graph. Classification becomes equivalent to partitioning the graph into two disjoint subgraphs. We use the Cheeger constant of the graph as an objective functional to derive the classifier. We represent the classifier as a linear combination of basis functions given from the spectral analysis of the graph Laplacian. Minimization of the Cheeger constant based functional leads to the optimal classifier. Experimental results and comparisons with other methods suggest the feasibility of our approach to study the rejection of hearts imaged by USPIO-enhanced MRI.

  17. Rotating reverse osmosis: a dynamic model for flux and rejection

    NASA Technical Reports Server (NTRS)

    Lee, S.; Lueptow, R. M.

    2001-01-01

    Reverse osmosis (RO) is a compact process for the removal of ionic and organic pollutants from contaminated water. However, flux decline and rejection deterioration due to concentration polarization and membrane fouling hinders the application of RO technology. In this study, a rotating cylindrical RO membrane is theoretically investigated as a novel method to reduce polarization and fouling. A dynamic model based on RO membrane transport incorporating concentration polarization is used to predict the performance of rotating RO system. Operating parameters such as rotational speed and transmembrane pressure play an important role in determining the flux and rejection in rotating RO. For a given geometry, a rotational speed sufficient to generate Taylor vortices in the annulus is essential to maintain high flux as well as high rejection. The flux and rejection were calculated for wide range of operating pressures and rotational speeds. c 2001 Elsevier Science B.V. All rights reserved.

  18. Reliability and construct validity for scale of rejection of Christianity.

    PubMed

    Robbins, Mandy; Francis, Leslie J; Bradford, Amanda

    2003-02-01

    A sample of 16 male and 30 female undergraduates completed the Greer and Francis Scale of Rejection of Christianity. The data support the internal consistency reliability and construct validity of the scale for this sample.

  19. Rotating reverse osmosis: a dynamic model for flux and rejection

    NASA Technical Reports Server (NTRS)

    Lee, S.; Lueptow, R. M.

    2001-01-01

    Reverse osmosis (RO) is a compact process for the removal of ionic and organic pollutants from contaminated water. However, flux decline and rejection deterioration due to concentration polarization and membrane fouling hinders the application of RO technology. In this study, a rotating cylindrical RO membrane is theoretically investigated as a novel method to reduce polarization and fouling. A dynamic model based on RO membrane transport incorporating concentration polarization is used to predict the performance of rotating RO system. Operating parameters such as rotational speed and transmembrane pressure play an important role in determining the flux and rejection in rotating RO. For a given geometry, a rotational speed sufficient to generate Taylor vortices in the annulus is essential to maintain high flux as well as high rejection. The flux and rejection were calculated for wide range of operating pressures and rotational speeds. c 2001 Elsevier Science B.V. All rights reserved.

  20. The Effect of Circumstantial Rejection on Infant Behavior

    ERIC Educational Resources Information Center

    Tait, Perla

    1972-01-01

    Intentional or unintentional rejection of a blind infant by the mother is shown to be conducive to the child's unwillingness to explore his environment, which in turn can have negative effects on the child's development. (CB)

  1. 48 CFR 14.404-2 - Rejection of individual bids.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... total price of the bid, but the prices for individual line items as well. (g) Any bid may be rejected if the prices for any line items or subline items are materially unbalanced (see 15.404-1(g)). (h)...

  2. Children's Use of Memory Editing Strategies to Reject Source Misinformation.

    PubMed

    Moore, Kara N; Lampinen, James M; Gallo, David A; Adams, Eryn J; Bridges, Ana J

    2017-02-15

    This is the first reported study of children's use of two metacognitive strategies, recollection rejection and diagnostic monitoring, to reject misinformation. Recollection rejection involves the retrieval of details that disqualify an event, whereas diagnostic monitoring involves the failure to retrieve expected details. First (n = 56, age 7 years) and third graders (n = 52, age 9 years) witnessed a staged classroom interaction involving common and bizarre accidents, were presented with misinformation about the source of these events, and took a memory test. Both age groups used recollection rejection, but third graders were more effective. There was little evidence that diagnostic monitoring influenced responses for bizarre events, potentially because these events were not sufficiently bizarre in the context of the stereotype induction.

  3. Maternal Predictors of Rejecting Parenting and Early Adolescent Antisocial Behavior

    PubMed Central

    Shaw, Daniel S.

    2009-01-01

    The present study examined relations among maternal psychological resources, rejecting parenting, and early adolescent antisocial behavior in a sample of 231 low-income mothers and their sons with longitudinal assessments from age 18 months to 12 years. The maternal resources examined were age at first birth, aggressive personality, and empathy. Each of the maternal resources predicted rejecting parenting during early childhood in structural equation models that controlled for toddler difficult temperament, and rejecting parenting in early childhood predicted antisocial behavior in early adolescence. Rejecting parenting accounted for the indirect effect of each of the maternal resources on antisocial behavior, but a direct effect was also supported between maternal aggressive personality and youth antisocial behavior. Results highlight the importance of these relatively understudied maternal resources and have implications for prevention and intervention programs that focus on parenting during early childhood. PMID:17805957

  4. Liquid droplet radiators for heat rejection in space

    NASA Technical Reports Server (NTRS)

    Mattick, A. T.; Hertzberg, A.

    1980-01-01

    A radiator for heat rejection in space is described which utilizes a stream of liquid droplets to radiate waste heat. The large surface area per mass makes the liquid droplet radiator at least an order of magnitude lighter than tube and fin radiators. Generation and collection of the droplets, as well as heat transfer to the liquid, can be achieved with modest extensions of conventional technology. Low vapor pressure liquids are available which cover a radiating temperature range 250-1000 K with negligible evaporation losses. The droplet radiator may be employed for a wide range of heat rejection applications in space. Three applications - heat rejection for a high temperature Rankine cycle, cooling of photovoltaic cells, and low temperature heat rejection for refrigeration in space illustrate the versatility of the radiator.

  5. 48 CFR 19.505 - Rejecting Small Business Administration recommendations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Administration recommendations. 19.505 Section 19.505 Federal Acquisition Regulations System FEDERAL ACQUISITION... Small Business Administration recommendations. (a) If the contracting officer rejects a recommendation... the recommendation. (b) The SBA procurement center representative (or, if a procurement...

  6. Maternal predictors of rejecting parenting and early adolescent antisocial behavior.

    PubMed

    Trentacosta, Christopher J; Shaw, Daniel S

    2008-02-01

    The present study examined relations among maternal psychological resources, rejecting parenting, and early adolescent antisocial behavior in a sample of 231 low-income mothers and their sons with longitudinal assessments from age 18 months to 12 years. The maternal resources examined were age at first birth, aggressive personality, and empathy. Each of the maternal resources predicted rejecting parenting during early childhood in structural equation models that controlled for toddler difficult temperament, and rejecting parenting in early childhood predicted antisocial behavior in early adolescence. Rejecting parenting accounted for the indirect effect of each of the maternal resources on antisocial behavior, but a direct effect was also supported between maternal aggressive personality and youth antisocial behavior. Results highlight the importance of these relatively understudied maternal resources and have implications for prevention and intervention programs that focus on parenting during early childhood.

  7. Lung rejection occurs in lung transplant recipients with blood chimerism.

    PubMed

    Knoop, C; Andrien, M; Defleur, V; Antoine, M; de Francquen, P; Goldman, M; Estenne, M

    1997-07-15

    It has been postulated that chimerism after transplantation might promote graft acceptance. In the present study, we prospectively assessed blood chimerism in 10 lung transplant recipients during the first posttransplant year and investigated whether chimerism was associated with an immunologically stable situation of the graft. The recipients' peripheral blood mononuclear cells were obtained before transplantation and at various time points during the first postoperative year. Donor cells were detected using nested polymerase chain reaction amplification of a donor-specific HLA-DRB1 allele. Clinical graft acceptance was determined by the number of rejection episodes. The incidence of blood chimerism was high during the first 3 postoperative months and then decreased over time. All patients experienced at least one acute rejection episode, and three patients developed chronic rejection. We, thus, conclude that rejection of the lung allograft may occur in the presence of blood chimerism.

  8. 48 CFR 19.505 - Rejecting Small Business Administration recommendations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Administration recommendations. 19.505 Section 19.505 Federal Acquisition Regulations System FEDERAL ACQUISITION... Small Business Administration recommendations. (a) If the contracting officer rejects a recommendation... the recommendation. (b) The SBA procurement center representative (or, if a procurement...

  9. 48 CFR 19.505 - Rejecting Small Business Administration recommendations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Administration recommendations. 19.505 Section 19.505 Federal Acquisition Regulations System FEDERAL ACQUISITION... Small Business Administration recommendations. (a) If the contracting officer rejects a recommendation... the recommendation. (b) The SBA procurement center representative (or, if a procurement...

  10. 7 CFR 56.24 - Rejection of application.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT (CONTINUED) VOLUNTARY GRADING OF SHELL EGGS Grading of Shell Eggs Application for Grading Service § 56.24 Rejection of application. (a) An...

  11. 7 CFR 56.24 - Rejection of application.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT (CONTINUED) VOLUNTARY GRADING OF SHELL EGGS Grading of Shell Eggs Application for Grading Service § 56.24 Rejection of application. (a) An...

  12. 7 CFR 56.24 - Rejection of application.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT (CONTINUED) VOLUNTARY GRADING OF SHELL EGGS Grading of Shell Eggs Application for Grading Service § 56.24 Rejection of application. (a) An...

  13. 7 CFR 56.24 - Rejection of application

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT (CONTINUED) VOLUNTARY GRADING OF SHELL EGGS Grading of Shell Eggs Application for Grading Service § 56.24 Rejection of application (a) An...

  14. 7 CFR 56.24 - Rejection of application

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT (CONTINUED) VOLUNTARY GRADING OF SHELL EGGS Grading of Shell Eggs Application for Grading Service § 56.24 Rejection of application (a) An...

  15. Acute antibody-mediated rejection in kidney transplant recipients.

    PubMed

    Davis, Scott; Cooper, James E

    2017-01-01

    Antibody-mediated rejection has now been recognized as one of the most important causes of graft loss. Transplantation across HLA barriers and nonadherence can result in acute antibody-mediated rejection, which is associated with particularly worse graft outcomes. New technologies, including genomic studies and assays to detect and define donor-specific antibodies, have provided important insights into the pathophysiology and diagnosis of acute antibody-mediated rejection but have engendered many questions about the clinical application of these tests in the prognosis and prevention of this protean disease process. In this article, we review the pathophysiology of acute antibody-mediated rejection, the evolving diagnostic criteria, and specific challenges related to its prognosis, treatment, and prevention.

  16. Simulation and verification of the cosmogenic background at the shallow depth GIOVE detector

    NASA Astrophysics Data System (ADS)

    Hakenmüller, J.; Maneschg, W.; Heusser, G.

    2016-05-01

    The GIOVE (Germanium Inner Outer VEto) detector setup is a low level Germanium spectrometer for material screening with elaborated shield located at the shallow depth underground laboratory of the Max-Planck-Institut für Kernphysik in Heidelberg. It is equipped with a double active muon veto with a total muon rejection efficiency of ~99% and there are also passive layers to moderate and capture neutrons. With this setup an integral count rate is achieved comparable to detectors far deeper underground. The detector and shield geometry has been implemented into a Monte Carlo simulation, using the simulation framework MaGe based on Geant4. The Monte Carlo simulation is employed to determine sample efficiencies for γ ray screening measurements as well as to reproduce the remaining detector background from cosmic ray muon-induced secondaries. In terms of the background modeling of the unvetoed γ ray spectrum an excellent agreement better than 10% in the integral count rate in (40, 2700) keV as well as for the 511 keV line has been found. However, concerning the expected number of neutrons at the diode, the simulation outcome lays 40-80% below the measurement results. Being able to reproduce the detector background in the simulation, the simulation can be used to further optimize the shield design.

  17. Background simulations for the wide field imager aboard the ATHENA X-ray Observatory

    NASA Astrophysics Data System (ADS)

    Hauf, Steffen; Kuster, Markus; Hoffmann, Dieter H. H.; Lang, Philipp-Michael; Neff, Stephan; Pia, Maria Grazia; Strüder, Lothar

    2012-09-01

    The ATHENA X-ray observatory was a European Space Agency project for a L-class mission. ATHENA was to be based upon a simplified IXO design with the number of instruments and the focal length of the Wolter optics being reduced. One of the two instruments, the Wide Field Imager (WFI) was to be a DePFET based focal plane pixel detector, allowing for high time and spatial resolution spectroscopy in the energy-range between 0.1 and 15 keV. In order to fulfill the mission goals a high sensitivity is essential, especially to study faint and extended sources. Thus a detailed understanding of the detector background induced by cosmic ray particles is crucial. During the mission design generally extensive Monte-Carlo simulations are used to estimate the detector background in order to optimize shielding components and software rejection algorithms. The Geant4 toolkit1,2 is frequently the tool of choice for this purpose. Alongside validation of the simulation environment with XMM-Newton EPIC-pn and Space Shuttle STS-53 data we present estimates for the ATHENA WFI cosmic ray induced background including long-term activation, which demonstrate that DEPFET-technology based detectors are able to achieve the required sensitivity.

  18. Intelligent background noise reduction technology in cable fault locator using the magneto-acoustic synchronous method

    NASA Astrophysics Data System (ADS)

    Mi, JianWei; Huang, JiFa; Fang, XiaoLi; Fan, LiBin

    2017-01-01

    The magneto-acoustic synchronous method has found wide application in accurate positioning of power cable fault due to its advantages of high accuracy and strong ability to reject interference. In the view of principle, the magneto-acoustic synchronous method needs to detect the discharge sound signal and electromagnetic signal emitted from the fault point, but the discharge sound signal is easy to be interfered by the ambient noise around and the magnetic sound synchronization. Therefore, it is challenging to quickly and accurately detect the fault location of cable especially in strong background noise environment. On the other hand, the spectral subtraction is a relatively traditional and effective method in many intelligent background noise reduction technologies, which is characterized by a relatively small computational cost and strong real-time performance. However, its application is limited because the algorithm displays poor performance in low Signal to Noise Ratio (SNR) environment. Aiming at the shortcoming of the spectral subtraction that de-noising effect is weak in low SNR environment, this paper proposes an improved spectral subtraction combining the magnetic sound synchronous principle and analyzing the properties of discharging sound. This method can accurately estimate noise in real time and optimize the performance of the basic spectral subtraction thus solving the problem that the magneto-acoustic synchronous method is unsatisfactory for positioning cable fault in the strong background noise environment.

  19. The Cosmic Background Explorer.

    ERIC Educational Resources Information Center

    Gulkis, Samuel; And Others

    1990-01-01

    Outlines the Cosmic Background Explorer (COBE) mission to measure celestial radiation. Describes the instruments used and experiments involving differential microwave radiometers, and a far infrared absolute spectrophotometer. (YP)

  20. The Cosmic Background Explorer.

    ERIC Educational Resources Information Center

    Gulkis, Samuel; And Others

    1990-01-01

    Outlines the Cosmic Background Explorer (COBE) mission to measure celestial radiation. Describes the instruments used and experiments involving differential microwave radiometers, and a far infrared absolute spectrophotometer. (YP)

  1. Steroid-resistant kidney transplant rejection: diagnosis and treatment.

    PubMed

    Bock, H A

    2001-02-01

    Decreases in transplant function may be attributable to a variety of conditions, including prerenal and postrenal failure, cyclosporin A (CsA) toxicity, polyoma nephritis, recurrent glomerulonephritis, and rejection. The diagnosis of rejection should therefore be made on the basis of a transplant biopsy of adequate size, before the initiation of any therapy. Pulse steroid treatment (three to five 0.25- to 1.0-g pulses of methylprednisolone, administered intravenously) is the usual first-line therapy and has a 60 to 70% success rate, although orally administered prednisone (0.25 g) may be just as efficacious. Even if reverted, any rejection should trigger an at least temporary increase in basal immunosuppression, consisting of an increase in CsA or tacrolimus target levels, the addition of steroids or an increase in their dosage, the addition of mycophenolate mofetil, or a switch from CsA to tacrolimus. The addition of rapamycin or its RAD derivative may fulfill the same purpose. Steroid resistance should not be assumed before the fifth day of pulse steroid treatment, although histologic features of vascular rejection may indicate the need for more aggressive treatment earlier. Steroid-resistant rejection is traditionally treated with poly- or monoclonal antilymphocytic antibodies, with success rates of 60 to 70%. Their potential benefit must be carefully balanced against the risks of infection and lymphoma. More recently, mycophenolate mofetil has been successfully used to treat steroid-resistant rejection, but only of the interstitial (cellular) type. Switching from CsA to tacrolimus for treating recurrent or antibody-resistant rejection is successful in approximately 60% of cases. Plasmapheresis and intravenously administered Ig have been used in some desperate cases, with surprising success. Because none of the available drugs has a significantly better profile of therapeutic versus adverse effects, the possible benefits of continued rejection therapy must be

  2. Virus Rejection by the Reverse Osmosis - Ultrafiltration Processes

    DTIC Science & Technology

    Rejection of viruses by commercial grade asymmetrical cellulose acetate membranes commonly used in the ultrafiltration and reverse osmosis processes...penetration of viruses may be attributable to the presence of random areas of imperfect crosslinkage of the cellulose acetate in the dense layer of...the membrane. Despite limited virus penetration, all of the cellulose acetate membranes used in this study rejected an extremely high percentage of the viruses and provided a product water of excellent quality.

  3. The private rejection of unfair offers and emotional commitment

    PubMed Central

    Yamagishi, Toshio; Horita, Yutaka; Takagishi, Haruto; Shinada, Mizuho; Tanida, Shigehito; Cook, Karen S.

    2009-01-01

    In a series of experiments, we demonstrate that certain players of an economic game reject unfair offers even when this behavior increases rather than decreases inequity. A substantial proportion (30–40%, compared with 60–70% in the standard ultimatum game) of those who responded rejected unfair offers even when rejection reduced only their own earnings to 0, while not affecting the earnings of the person who proposed the unfair split (in an impunity game). Furthermore, even when the responders were not able to communicate their anger to the proposers by rejecting unfair offers in a private impunity game, a similar rate of rejection was observed. The rejection of unfair offers that increases inequity cannot be explained by the social preference for inequity aversion or reciprocity; however, it does provide support for the model of emotion as a commitment device. In this view, emotions such as anger or moral disgust lead people to disregard the immediate consequences of their behavior, committing them to behave consistently to preserve integrity and maintain a reputation over time as someone who is reliably committed to this behavior. PMID:19564602

  4. Prevention trumps treatment of antibody-mediated transplant rejection

    PubMed Central

    Knechtle, Stuart J.; Kwun, Jean; Iwakoshi, Neal

    2010-01-01

    Belying the spectacular success of solid organ transplantation and improvements in immunosuppressive therapy is the reality that long-term graft survival rates remain relatively unchanged, in large part due to chronic and insidious alloantibody-mediated graft injury. Half of heart transplant recipients develop chronic rejection within 10 years — a daunting statistic, particularly for young patients expecting to achieve longevity by enduring the rigors of a transplant. The current immunosuppressive pharmacopeia is relatively ineffective in preventing late alloantibody-associated chronic rejection. In this issue of the JCI, Kelishadi et al. report that preemptive deletion of B cells prior to heart transplantation in cynomolgus monkeys, in addition to conventional posttransplant immunosuppressive therapy with cyclosporine, markedly attenuated not only acute graft rejection but also alloantibody elaboration and chronic graft rejection. The success of this preemptive strike implies a central role for B cells in graft rejection, and this approach may help to delay or prevent chronic rejection after solid organ transplantation. PMID:20335653

  5. Phenotypes of antibody-mediated rejection in organ transplants.

    PubMed

    Mengel, Michael; Husain, Sufia; Hidalgo, Luis; Sis, Banu

    2012-06-01

    Antibody-mediated hyperacute rejection was the first rejection phenotype observed in human organ transplants. This devastating phenotype was eliminated by reliable crossmatch technologies. Since then, the focus was on T-cell-mediated rejection and de novo donor-specific antibodies were considered an epiphenomenon of cognate T-cell activation. The immune theory was that controlling the T-cell response would entail elimination of antibody-mediated rejection (ABMR). With modern immunosuppressive drugs, T-cell-mediated rejection is essentially treatable. However, this did not prevent ABMR from emerging as a significant phenotype in all types of organ transplants. It became obvious that both rejection types require distinct treatment and thus reliable diagnosis. This is the current challenge. ABMR, depending on stage, grade, time course, organ type or prior treatment, can present with a wide spectrum of phenotypes. This review summarizes the current diagnostic consensus for ABMR, describes unmet needs and challenges in diagnostics, and proposes new approaches for consideration. © 2012 The Authors. Transplant International © 2012 European Society for Organ Transplantation.

  6. Confuser rejection performance of EMACH filters for MSTAR ATR

    NASA Astrophysics Data System (ADS)

    Casasent, David; Nehemiah, Avinash

    2006-04-01

    Synthetic aperture radar (SAR) automatic target recognition (ATR) based on the extended maximum average correlation height (EMACH) distortion invariant filter (DIF) is presented. Prior work on the EMACH filter addresses 3-class and 10 class classification with clutter rejection. However, the ability of the EMACH filter to reject confusers is not well known. This paper addresses this. We follow a benchmark procedure which involves classification of three object classes over 360° aspect angle differences and with depression angle and variant differences and rejection of two unseen confusers from the Moving and Stationary Target Acquisition and Recognition (MSTAR) public database. We present a scheme to select which training set images to include while making the filters, since it is not necessary to use all training set images to make the filters. Results for classification with both confuser and clutter rejection are presented. We also compare our work with prior EMACH MSTAR work. We find EMACH filters to have poor confuser and clutter rejection. We also correct prior EMACH clutter rejection performance results.

  7. The private rejection of unfair offers and emotional commitment.

    PubMed

    Yamagishi, Toshio; Horita, Yutaka; Takagishi, Haruto; Shinada, Mizuho; Tanida, Shigehito; Cook, Karen S

    2009-07-14

    In a series of experiments, we demonstrate that certain players of an economic game reject unfair offers even when this behavior increases rather than decreases inequity. A substantial proportion (30-40%, compared with 60-70% in the standard ultimatum game) of those who responded rejected unfair offers even when rejection reduced only their own earnings to 0, while not affecting the earnings of the person who proposed the unfair split (in an impunity game). Furthermore, even when the responders were not able to communicate their anger to the proposers by rejecting unfair offers in a private impunity game, a similar rate of rejection was observed. The rejection of unfair offers that increases inequity cannot be explained by the social preference for inequity aversion or reciprocity; however, it does provide support for the model of emotion as a commitment device. In this view, emotions such as anger or moral disgust lead people to disregard the immediate consequences of their behavior, committing them to behave consistently to preserve integrity and maintain a reputation over time as someone who is reliably committed to this behavior.

  8. Diagnostic criteria of antibody-mediated rejection in kidney transplants.

    PubMed

    Mosquera Reboredo, J M; Vázquez Martul, E

    2011-01-01

    The diagnosis and treatment of anti-donor antibody-mediated rejection or humoral rejection (ABMR) is one of the main discussions at the moment in kidney transplantation. The search for histopathological markers that help us to diagnose ABMR has been more problematic, in contrast to the histological expression of cellular or tubulointerstitial rejection. Although the relationship between post-transplant anti-donor antibodies and the allograft's prognosis has been a topic of discussion for a long time, led in the main by P.Terasaki, it was not until the beginning of 1990s when P. Halloran studied the humoral mechanisms of rejection in greater depth. Feutch described the importance of C4d deposits as a marker that shows a humoral mechanism of allograft rejection in 1993. As a result of many studies carried out, the Banff consensus group established some diagnostic histopathological criteria of acute (ABMR) in 2003. These have been modified slightly in later meetings of the group. Furthermore, in 2005 this same working group looked at the physiopathological mechanisms causing chronic allograft failure in more detail and established the criteria defining chronic humoral rejection. In this review, we are trying to update any useful histopathological criteria for diagnosing acute and chronic ABMR.

  9. Diagonal rejection-based minimum variance distortionless response for fiber underwater acoustic array

    NASA Astrophysics Data System (ADS)

    Chen, Yang; Zou, Ling; Zhou, Bin

    2017-07-01

    The high mounting precision of the fiber underwater acoustic array leads to an array manifold without perturbation. Besides, the targets are either static or slowly moving in azimuth in underwater acoustic array signal processing. Therefore, the covariance matrix can be estimated accurately by prolonging the observation time. However, this processing is limited to poor bearing resolution due to small aperture, low SNR and strong interferences. In this paper, diagonal rejection (DR) technology for Minimum Variance Distortionless Response (MVDR) was developed to enhance the resolution performance. The core idea of DR is rejecting the main diagonal elements of the covariance matrix to improve the output signal to interference and noise ratio (SINR). The definition of SINR here implicitly assumes independence between the spatial filter and the received observations at which the SINR is measured. The power of noise converges on the diagonal line in the covariance matrix and then it is integrated into the output beams. With the diagonal noise rejected by a factor smaller than 1, the array weights of MVDR will concentrate on interference suppression, leading to a better resolution capability. The algorithm was theoretically proved with optimal rejecting coefficient derived under both infinite and finite snapshots scenarios. Numerical simulations were conducted with an example of a linear array with eight elements half-wavelength spaced. Both resolution and Direction-of-Arrival (DOA) performances of MVDR and DR-based MVDR (DR-MVDR) were compared under different SNR and snapshot numbers. A conclusion can be drawn that with the covariance matrix accurately estimated, DR-MVDR can provide a lower sidelobe output level and a better bearing resolution capacity than MVDR without harming the DOA performance.

  10. A study of nuclear recoil backgrounds in dark matter detectors

    NASA Astrophysics Data System (ADS)

    Westerdale, Shawn S.

    Despite the great success of the Standard Model of particle physics, a preponderance of astrophysical evidence suggests that it cannot explain most of the matter in the universe. This so-called dark matter has eluded direct detection, though many theoretical extensions to the Standard Model predict the existence of particles with a mass on the 1-1000 GeV scale that interact only via the weak nuclear force. Particles in this class are referred to as Weakly Interacting Massive Particles (WIMPs), and their high masses and low scattering cross sections make them viable dark matter candidates. The rarity of WIMP-nucleus interactions makes them challenging to detect: any background can mask the signal they produce. Background rejection is therefore a major problem in dark matter detection. Many experiments greatly reduce their backgrounds by employing techniques to reject electron recoils. However, nuclear recoil backgrounds, which produce signals similar to what we expect from WIMPs, remain problematic. There are two primary sources of such backgrounds: surface backgrounds and neutron recoils. Surface backgrounds result from radioactivity on the inner surfaces of the detector sending recoiling nuclei into the detector. These backgrounds can be removed with fiducial cuts, at some cost to the experiment's exposure. In this dissertation we briefly discuss a novel technique for rejecting these events based on signals they make in the wavelength shifter coating on the inner surfaces of some detectors. Neutron recoils result from neutrons scattering off of nuclei in the detector. These backgrounds may produce a signal identical to what we expect from WIMPs and are extensively discussed here. We additionally present a new tool for calculating (alpha, n) yields in various materials. We introduce the concept of a neutron veto system designed to shield against, measure, and provide an anti-coincidence veto signal for background neutrons. We discuss the research and development

  11. A Study of Nuclear Recoil Backgrounds in Dark Matter Detectors

    SciTech Connect

    Westerdale, Shawn S.

    2016-01-01

    Despite the great success of the Standard Model of particle physics, a preponderance of astrophysical evidence suggests that it cannot explain most of the matter in the universe. This so-called dark matter has eluded direct detection, though many theoretical extensions to the Standard Model predict the existence of particles with a mass on the $1-1000$ GeV scale that interact only via the weak nuclear force. Particles in this class are referred to as Weakly Interacting Massive Particles (WIMPs), and their high masses and low scattering cross sections make them viable dark matter candidates. The rarity of WIMP-nucleus interactions makes them challenging to detect: any background can mask the signal they produce. Background rejection is therefore a major problem in dark matter detection. Many experiments greatly reduce their backgrounds by employing techniques to reject electron recoils. However, nuclear recoil backgrounds, which produce signals similar to what we expect from WIMPs, remain problematic. There are two primary sources of such backgrounds: surface backgrounds and neutron recoils. Surface backgrounds result from radioactivity on the inner surfaces of the detector sending recoiling nuclei into the detector. These backgrounds can be removed with fiducial cuts, at some cost to the experiment's exposure. In this dissertation we briefly discuss a novel technique for rejecting these events based on signals they make in the wavelength shifter coating on the inner surfaces of some detectors. Neutron recoils result from neutrons scattering from nuclei in the detector. These backgrounds may produce a signal identical to what we expect from WIMPs and are extensively discussed here. We additionally present a new tool for calculating ($\\alpha$, n)yields in various materials. We introduce the concept of a neutron veto system designed to shield against, measure, and provide an anti-coincidence veto signal for background neutrons. We discuss the research and development

  12. Solar rejection for an orbiting telescope

    NASA Technical Reports Server (NTRS)

    Rehnberg, J. D.

    1975-01-01

    The present work discusses some of the constraints that the optical designer must deal with in optimizing spaceborne sensors that must look at or near the sun. Analytical techniques are described for predicting the effects of stray radiation from sources such as mirror scatter, baffle scatter, diffraction, and ghost images. In addition, the paper describes a sensor design that has been flown on the Apollo Telescope Mount (Skylab) to aid astronauts in locating solar flares. In addition to keeping stray radiation to a minimum, the design had to be nondegradable by the direct solar heat load.

  13. Solar rejection for an orbiting telescope

    NASA Technical Reports Server (NTRS)

    Rehnberg, J. D.

    1975-01-01

    The present work discusses some of the constraints that the optical designer must deal with in optimizing spaceborne sensors that must look at or near the sun. Analytical techniques are described for predicting the effects of stray radiation from sources such as mirror scatter, baffle scatter, diffraction, and ghost images. In addition, the paper describes a sensor design that has been flown on the Apollo Telescope Mount (Skylab) to aid astronauts in locating solar flares. In addition to keeping stray radiation to a minimum, the design had to be nondegradable by the direct solar heat load.

  14. Background Extraction Using Random Walk Image Fusion.

    PubMed

    Hua, Kai-Lung; Wang, Hong-Cyuan; Yeh, Chih-Hsiang; Cheng, Wen-Huang; Lai, Yu-Chi

    2016-12-23

    It is important to extract a clear background for computer vision and augmented reality. Generally, background extraction assumes the existence of a clean background shot through the input sequence, but realistically, situations may violate this assumption such as highway traffic videos. Therefore, our probabilistic model-based method formulates fusion of candidate background patches of the input sequence as a random walk problem and seeks a globally optimal solution based on their temporal and spatial relationship. Furthermore, we also design two quality measures to consider spatial and temporal coherence and contrast distinctness among pixels as background selection basis. A static background should have high temporal coherence among frames, and thus, we improve our fusion precision with a temporal contrast filter and an optical-flow-based motionless patch extractor. Experiments demonstrate that our algorithm can successfully extract artifact-free background images with low computational cost while comparing to state-of-the-art algorithms.

  15. Correlators in nontrivial backgrounds

    SciTech Connect

    Mello Koch, Robert de; Ives, Norman; Stephanou, Michael

    2009-01-15

    Operators in N=4 super Yang-Mills theory with an R-charge of O(N{sup 2}) are dual to backgrounds which are asymtotically AdS{sub 5}xS{sup 5}. In this article we develop efficient techniques that allow the computation of correlation functions in these backgrounds. We find that (i) contractions between fields in the string words and fields in the operator creating the background are the field theory accounting of the new geometry, (ii) correlation functions of probes in these backgrounds are given by the free field theory contractions but with rescaled propagators and (iii) in these backgrounds there are no open string excitations with their special end point interactions; we have only closed string excitations.

  16. Treatment of simultaneous acute antibody-mediated rejection and acute cellular rejection with alemtuzumab in kidney transplantation: a case report.

    PubMed

    Jirasiritham, S; Khunprakant, R; Techawathanawanna, N; Jirasiritham, Si; Mavichak, V

    2010-04-01

    This is a case report of a living related donor kidney transplantation using basiliximab induction and maintenance immunosuppression with cyclosporine, mycophenolate sodium, and steroid. On the second posttransplant day, the patient developed acute antibody-mediated rejection, which was treated with plasmapheresis and intravenous immunoglobulin (IVIG). Five days later, the graft had still not responded to the treatment. Another biopsy revealed additional acute cellular rejection (Banff IIA). As alemtuzumab can rapidly deplete T and B lymphocytes, monocytes, and natural killer cells, the patient was treated with alemtuzumab (30 mg subcutaneously) together with methylprednisolone (500 mg) and two more plasmaphereses. The kidney graft responded within 48 hours, producing more than 4 L of urine per day. The total lymphocyte decreased from 530/microL to 50/microL remaining in the 50 to 220/microL range. The patient received valgancyclovir and cotrimoxazole as infection prophylaxis. The kidney graft responded well to the rescue treatment and the patient was discharged with a serum creatinine of 1.1 mg/mL and has been uneventfully followed in the outpatient clinic for 8 months. Today, with the potent, effective, and selective immunosuppressive regimens, the rate and severity of acute cellular rejection in kidney transplantation has decreased in most centers. However, the rate of acute antibody-mediated rejection has increased to levels greater than those of acute cellular rejection in many centers. Acute antibody-mediated rejection is more difficult and expensive to treat successfully. The treatment of acute antibody-mediated rejection included plasmapheresis and IVIG. Herein we have reported a case of kidney transplantation simultaneously developing acute antibody-mediated and acute cellular rejection; the patient was successfully treated with alemtuzumab.

  17. Effect of deoxyspergualin on vascular rejection in canine kidney transplantation.

    PubMed

    Tanabe, K; Takahashi, K; Nemoto, K; Okada, M; Yasuo, M; Hayasaka, Y; Toma, H; Ota, K

    1994-08-01

    Deoxyspergualin (DSG), an analogue of spergualin produced by Bacillus laterosporus, has a strong immunosuppressive effect in various transplantation models. In this study, we investigated the effect of DSG on vascular rejection in canine kidney transplantation. To enhance vascular rejection, donor-specific blood transfusion (DST) was carried out on days 28, 21 and 14 preceding kidney transplantation. After DST, the donor kidney was transplanted to the recipient iliac fossa. The recipient animals were divided into five groups: namely, Group 1 (n = 7), no treatment; Group 2 (n = 6), DST only; Group 3 (n = 5), DSG only (treated with DSG intravenously at 1.2 mg./kg./day for the first 3 days after transplantation, 1.0 mg./kg./day for the following 3 days and 0.8 mg./kg./day for the following 8 days); Group 4 (n = 6), DST and DSG treatment (same protocol as Group 3); and Group 5 (n = 5), DST and cyclosporine (CsA) (treated with CsA orally at 10 mg./kg./day for 14 days after transplantation). In Group 2, DST treatment significantly reduced kidney graft survival time (8.6 +/- 2.2 days) compared with Group 1 (14.1 +/- 5.5 days). Despite DST, DSG treatment (Group 4) significantly prolonged graft survival time (29.5 +/- 2.6 days), whereas treatment with CsA (Group 5) did not prolong survival time (14.1 +/- 5.5 days) (Group 4 versus 5, p < 0.01). The onset of rejection was significantly delayed in Group 4 (22.1 +/- 2.7 days) compared with Groups 2 (5.7 +/- 2.4 days) and 5 (13.0 +/- 5.7 days) (p < 0.01). In contrast, the interval between rejection onset and animal death was significantly reduced in Groups 2 (3.0 +/- 0.6 days) and 5 (2.4 +/- 1.0 days) compared with Group 4 (7.3 +/- 1.7 days) (p < 0.01). These findings suggest that DSG successfully prevented humoral-type (accelerated acute-type) rejections. Histologically, nonDST groups (Groups 1 and 3) showed minimum vascular rejection. In contrast, all recipients in Group 2 showed severe vascular rejection, as did 80% of Cs

  18. Cosmic microwave background measurements can discriminate among inflation models

    SciTech Connect

    Dodelson, S. |

    1997-09-01

    Quantum fluctuations during inflation may be responsible for temperature anisotropies in the cosmic microwave background (CMB). Observations of CMB anisotropies can be used to falsify many currently popular models. In this paper we discuss the prospectus for observations of CMB anisotropies at the accuracy of planned satellite missions to reject currently popular inflation models and to provide some direction for model building. {copyright} {ital 1997} {ital The American Physical Society}

  19. Background model for the Majorana Demonstrator

    NASA Astrophysics Data System (ADS)

    Cuesta, C.; Majorana Collaboration

    2017-09-01

    The Majorana Collaboration is constructing a system containing 44 kg of high-purity Ge (HPGe) detectors to demonstrate the feasibility and potential of a future tonne-scale experiment capable of probing the neutrino mass scale to ∼15 meV. To realize this, a major goal of the Majorana Demonstrator is to demonstrate a path forward to achieving a background rate at or below 1 count/(ROI-t-y) in the 4 keV region of interest (ROI) around the Q-value at 2039 keV. This goal is pursued through a combination of a significant reduction of radioactive impurities in construction materials and analytical methods for background rejection, for example using powerful pulse shape analysis techniques profiting from the p-type point contact (PPC) HPGe detectors technology. The effectiveness of these methods is assessed using simulations of the different background components whose purity levels are constrained from radioassay measurements. Preliminary background results obtained during the engineering runs of the Demonstrator are presented.

  20. Background Underground at WIPP

    NASA Astrophysics Data System (ADS)

    Esch, Ernst-Ingo; Hime, A.; Bowles, T. J.

    2001-04-01

    Recent interest to establish a dedicated underground laboratory in the United States prompted an experimental program at to quantify the enviromental backgrounds underground at the Waste Isolation Pilot Plant (WIPP) in Carlsbad, New Mexico. An outline of this program is provided along with recent experimental data on the cosmic ray muon flux at the 650 meter level of WIPP. The implications of the cosmic ray muon and fast neutron background at WIPP will be discussed in the context of new generation, low background experiments envisioned in the future.

  1. The cosmic neutrino background

    NASA Technical Reports Server (NTRS)

    Dar, Arnon

    1991-01-01

    The cosmic neutrino background is expected to consist of relic neutrinos from the big bang, of neutrinos produced during nuclear burning in stars, of neutrinos released by gravitational stellar collapse, and of neutrinos produced by cosmic ray interactions with matter and radiation in the interstellar and intergalactic medium. Formation of baryonic dark matter in the early universe, matter-antimatter annihilation in a baryonic symmetric universe, and dark matter annihilation could have also contributed significantly to the cosmic neutrino background. The purpose of this paper is to review the properties of these cosmic neutrino backgrounds, the indirect evidence for their existence, and the prospects for their detection.

  2. Reverse osmosis membrane rejection for ersatz space mission wastewaters.

    PubMed

    Yoon, Yeomin; Lueptow, Richard M

    2005-09-01

    Adequate rejection of a variety of inorganic and organic compounds is necessary if reverse osmosis (RO) and nanofiltration (NF) membranes are to be used for space mission wastewater reuse. Three ersatz space mission wastewaters defined by NASA having different pH (2.6-8.9), conductivities (3980-12,640 microS/cm), and amounts of organic compounds (50-2400 mg/L as carbon) were tested to determine the membrane flux and the solute rejection for five RO and two NF membranes that are commercially available. The results show that the rejection of ions depends upon the solution pH which influences electrostatic repulsion. However, the rejection of dissolved organic carbon (DOC) depends upon the composition of the wastewater. The DOC rejection (80-95%) was the highest for the wastewater containing dextran (molecular weight 15-20 k) compared with the other ersatz wastewaters having detergent and urea as the major carbon sources (31-83%). The wastewater having the greatest conductivity (12,640 microS/cm) and DOC (2400 mg/L) showed a greater flux decline (71-96%) than the other ersatz wastewaters (37-82%) having lower conductivities (3980-6980 microS/cm) and DOC (50-660 mg/L) for the RO and NF membranes. The ratio of solute radius (r(i,s)) to effective membrane pore radius (r(p)) was employed to compare ion rejection. For ionic compounds, the rejection is higher than 70% when the r(i,s)/r(p) ratio is greater than 0.5 for both the RO and NF membranes with all wastewaters.

  3. Gravitational wave background from rotating neutron stars

    NASA Astrophysics Data System (ADS)

    Rosado, Pablo A.

    2012-11-01

    The background of gravitational waves produced by the ensemble of rotating neutron stars (which includes pulsars, magnetars, and gravitars) is investigated. A formula for Ω(f) (a function that is commonly used to quantify the background, and is directly related to its energy density) is derived, without making the usual assumption that each radiating system evolves on a short time scale compared to the Hubble time; the time evolution of the systems since their formation until the present day is properly taken into account. Moreover, the formula allows one to distinguish the different parts of the background: the unresolvable (which forms a stochastic background or confusion noise, since the waveforms composing it cannot be either individually observed or subtracted out of the data of a detector) and the resolvable. Several estimations of the background are obtained, for different assumptions on the parameters that characterize neutron stars and their population. In particular, different initial spin period distributions lead to very different results. For one of the models, with slow initial spins, the detection of the background by present or planned detectors can be rejected. However, other models do predict the detection of the background, that would be unresolvable, by the future ground-based gravitational wave detector ET. A robust upper limit for the background of rotating neutron stars is obtained; it does not exceed the detection threshold of two cross-correlated Advanced LIGO interferometers. If gravitars exist and constitute more than a few percent of the neutron star population, then they produce an unresolvable background that could be detected by ET. Under the most reasonable assumptions on the parameters characterizing a neutron star, the background is too faint to be detected. Previous papers have suggested neutron star models in which large magnetic fields (like the ones that characterize magnetars) induce big deformations in the star, which

  4. Notification: Background Investigation Services

    EPA Pesticide Factsheets

    Project #OA-FY15-0029, February 26, 2015. The Office of Inspector General (OIG) for the U.S. Environmental Protection Agency (EPA) plans to begin field work for our audit of background investigation services.

  5. Bayesian background estimation

    NASA Astrophysics Data System (ADS)

    Fischer, R.; Dose, V.; Hanson, K. M.; von der Linden, W.

    2001-05-01

    The ubiquitous problem of estimating the background of a measured spectrum is solved with Bayesian probability theory. A mixture model is used to capture the defining characteristics of the problem, namely that the background is smoother than the signal. The smoothness property is quantified in terms of a cubic spline basis where a variable degree of smoothness is attained by allowing the number of knots and the knot positions to be adaptively chosen on the basis of the data. The fully Bayesian approach taken provides a natural way to handle knot adaptivity, allows uncertainties in the background to be estimated and data points to be classified in groups containing only background and groups with additional signal contribution. Our technique is demonstrated on a PIXE spectrum from a geological sample and an Auger spectrum from an 10 monolayer iron film on tungsten.

  6. Electronically controlled rejections of spoof surface plasmons polaritons

    NASA Astrophysics Data System (ADS)

    Zhou, Yong Jin; Xiao, Qian Xun

    2017-03-01

    We have proposed and experimentally demonstrated a band-notched surface plasmonic filter, which is composed of an ultra-wide passband plasmonic filter with a simple C-shaped ring on the back of the substrate. Enhanced narrowband or broadband rejections of spoof surface plasmon polaritons (SPPs) can be achieved with double C-shaped rings in the propagation or transverse direction. By mounting active components across the slit cut in the C-shaped ring, dynamic control of rejection of spoof SPPs can be accomplished. Both the rejection of spoof SPPs and the rejection bandwidth can be controlled when the Schottky barrier diode is forward-biased or reverse-biased. The frequency spectrum of the rejection band can be electronically adjusted by tuning the applied bias voltage across the varactor diode. Both simulated and measured results agree well and demonstrate dynamic control of propagation of spoof SPPs at the microwave frequencies. Such electronically controllable devices could find more applications in advanced plasmonic integrated functional circuits in microwave and terahertz frequencies.

  7. Amino acid rejection behaviour as a function of concentration.

    PubMed

    Shirley, Jason; Mandale, Stephen; Williams, Paul M

    2011-05-11

    The solute rejection versus concentration behaviour of five different amino acids has been investigated using a Nitto Denko NTR7450 nanofiltration membrane. The experimental data for amino acid rejection was also compared against a combined steric and charge rejection model. At its isoelectric point, lysine was effectively neutral and its behaviour was well described by the model incorporating a steric function only. For phenylalanine, the combined model was found to fit the data well. In contrast there was poor agreement between the model and rejection data for glutamine, glutamic acid and glycine whose rejection values at first increased with concentration. This result implied that another governing process was in operation. Dimerisation as an explanation for the observed phenomena was also investigated. Size analysis of amino acid molecules as a function of the prevailing concentration using dynamic light scattering was limited but showed no evidence of dimerisation. This data was supported by osmotic pressure measurements which demonstrated no evidence of non-linearity in the relation between osmotic pressure and concentration.

  8. The composition of the microbiota modulates allograft rejection

    PubMed Central

    Lei, Yuk Man; Chen, Luqiu; Wang, Ying; Stefka, Andrew T.; Molinero, Luciana L.; Theriault, Betty; Aquino-Michaels, Keston; Sivan, Ayelet S.; Nagler, Cathryn R.; Gajewski, Thomas F.; Chong, Anita S.; Bartman, Caroline

    2016-01-01

    Transplantation is the only cure for end-stage organ failure, but without immunosuppression, T cells rapidly reject allografts. While genetic disparities between donor and recipient are major determinants of the kinetics of transplant rejection, little is known about the contribution of environmental factors. Because colonized organs have worse transplant outcome than sterile organs, we tested the influence of host and donor microbiota on skin transplant rejection. Compared with untreated conventional mice, pretreatment of donors and recipients with broad-spectrum antibiotics (Abx) or use of germ-free (GF) donors and recipients resulted in prolonged survival of minor antigen–mismatched skin grafts. Increased graft survival correlated with reduced type I IFN signaling in antigen-presenting cells (APCs) and decreased priming of alloreactive T cells. Colonization of GF mice with fecal material from untreated conventional mice, but not from Abx-pretreated mice, enhanced the ability of APCs to prime alloreactive T cells and accelerated graft rejection, suggesting that alloimmunity is modulated by the composition of microbiota rather than the quantity of bacteria. Abx pretreatment of conventional mice also delayed rejection of major antigen–mismatched skin and MHC class II–mismatched cardiac allografts. This study demonstrates that Abx pretreatment prolongs graft survival, suggesting that targeting microbial constituents is a potential therapeutic strategy for enhancing graft acceptance. PMID:27322054

  9. Cellular requirements for the rejection of skin allografts in rats.

    PubMed

    Lubaroff, D M

    1973-08-01

    The role of bone marrow-derived cells in the rejection of skin allografts in rats was investigated. Lewis rats, rendered tolerant of BN antigens and bearing healthy grafts, were thymectomized, irradiated with 900 rad, and injected with varying doses of either normal isologous bone marrow, normal lymph node cells, and/or lymph node cells presensitized to BN antigens. In some experiments rats were also adoptively sensitized to tuberculin. Results showed that, although necessary for the elicitation of tuberculin skin reactions, bone marrow cells are not needed for the rejection of previously tolerated skin allografts. Rats receiving lymph node cells alone rejected their grafts in about 6-7 days. In addition, rats injected with bone marrow alone also rejected their grafts, although significantly later than did lymph node cell recipients, indicating that rat marrow contains a population of cells capable of reacting to transplantation antigens. These cells were found capable of reacting to major transplantation antigens but not minor as they were ineffective in causing the rejection of Ag-B compatible Fischer skin grafts. From experiments utilizing bone marrow from neonatally thymectomized donors and cells treated with an antiserum to rat T cells, these competent cells in the marrow were shown to be thymus derived.

  10. Alemtuzumab Induction and Delayed Acute Rejection in Steroid-Free Simultaneous Pancreas-Kidney Transplant Recipients.

    PubMed

    Bank, Jonna R; Heidt, Sebastiaan; Moes, Dirk Jan A R; Roelen, Dave L; Mallat, Marko J K; van der Boog, Paul J M; Vergunst, Manon; Jol-van der Zijde, Cornelia M; Bredius, Robbert G M; Braat, Andries E; Ringers, Jan; van Tol, Maarten J D; Claas, Frans H J; Reinders, Marlies E J; de Fijter, Johannes W

    2017-01-01

    The optimal immunosuppressive regimen in simultaneous pancreas-kidney transplant (SPKT) recipients that prevents acute rejection episodes (AREs) and allows optimal outcome remains elusive. This cohort study assessed incidence and time to AREs in 73 consecutive SPKT recipients receiving alemtuzumab induction and steroid-free maintenance with tacrolimus and mycophenolate mofetil. A cohort with single high-dose antithymocyte globulin (ATG; n = 85) and triple therapy served as controls. In addition, we provided mechanistic insights in AREs after alemtuzumab depletion, including composition and alloreactivity of lymphocytes (flow cytometry and mixed lymphocyte reaction) plasma alemtuzumab levels (enzyme-linked immunosorbent assay), and maintenance drug exposure. Overall number of AREs at 3 years was significantly lower with alemtuzumab versus ATG induction (26.0% vs 43.5%; adjusted hazard ratio, 0.38; P = 0.029). Most AREs (94.6%) with ATG occurred within the first month, whereas 84.2% of AREs with alemtuzumab occurred beyond 3 months. Patients with and without an ARE in the steroid-free alemtuzumab group showed no differences in composition of lymphocytes, or in alemtuzumab levels. Of note, more than two thirds of these AREs were preceded by empiric tacrolimus and/or mycophenolate mofetil dose adjustments due to viral infections, leukopenia, or gastrointestinal symptoms. Alemtuzumab induction resulted in a significant lower incidence of AREs. Empiric dose adjustments beyond 3 months in the absence of steroids carry a significant risk for subsequent rejection in SPKT recipients.

  11. Relational Victimization and Rejection Sensitivity: The Long-Term Impact of Social Hurt

    ERIC Educational Resources Information Center

    Mellin, Elizabeth A.

    2012-01-01

    The Rejection Sensitivity Model is used to examine the social antecedents to expectations of rejection among adults. College students (N = 314) completed measures of relational victimization and rejection sensitivity. Results indicate that relational victimization is significantly related to rejection sensitivity for women. Implications for…

  12. Relational Victimization and Rejection Sensitivity: The Long-Term Impact of Social Hurt

    ERIC Educational Resources Information Center

    Mellin, Elizabeth A.

    2012-01-01

    The Rejection Sensitivity Model is used to examine the social antecedents to expectations of rejection among adults. College students (N = 314) completed measures of relational victimization and rejection sensitivity. Results indicate that relational victimization is significantly related to rejection sensitivity for women. Implications for…

  13. Sexual Education In Malaysia: Accepted Or Rejected?

    PubMed Central

    Mohd Mutalip, Siti Syairah; Mohamed, Ruzianisra

    2012-01-01

    Background: Introduction to sexual education in schools was suggested by the Malaysian government as one of the effort taken in the aim to reduce the sexual-related social problems among Malaysian teenagers nowadays. This study was proposed in the aim to determine the rate of acceptance among adolescents on the implementation of sexual education in schools. Methods: This study was conducted using questionnaires distributed to 152 pre-degree students in Faculty of Pharmacy, Universiti Teknologi MARA (UiTM), Kampus Puncak Alam, Selangor, Malaysia. Obtained data were statistically analyzed. Results: Almost half (49.3%) of the respondents agreed that sexual education might help to overcome the social illness among school teenagers. Besides, a large number (77.6%) of respondents also agreed that this module should be incorporated with other core subjects compare to the feedback received on the implementation of this module on its own (28.9%). Conclusion: These results have provided some insight towards the perception of sexual education among the teenagers. Since most of the respondents agreed with this idea, so it might be a sign that the implementation of sexual education is almost accepted by the adolescents. PMID:23113207

  14. Thermal control systems for low-temperature heat rejection on a lunar base

    NASA Technical Reports Server (NTRS)

    Sridhar, K. R.; Gottmann, Matthias

    1992-01-01

    One of the important issues in the lunar base architecture is the design of a Thermal Control System (TCS) to reject the low temperature heat from the base. The TCS ensures that the base and all components inside are maintained within the operating temperature range. A significant portion of the total mass of the TCS is due to the radiator. Shading the radiation from the sun and the hot lunar soil could decrease the radiator operating temperature significantly. Heat pumps have been in use for terrestrial applications. To optimize the mass of the heat pump augmented TCS, all promising options have to be evaluated and compared. Careful attention is given to optimizing system operating parameters, working fluids, and component masses. The systems are modeled for full load operation.

  15. Data augmentation for models based on rejection sampling

    PubMed Central

    Rao, Vinayak; Lin, Lizhen; Dunson, David B.

    2016-01-01

    We present a data augmentation scheme to perform Markov chain Monte Carlo inference for models where data generation involves a rejection sampling algorithm. Our idea is a simple scheme to instantiate the rejected proposals preceding each data point. The resulting joint probability over observed and rejected variables can be much simpler than the marginal distribution over the observed variables, which often involves intractable integrals. We consider three problems: modelling flow-cytometry measurements subject to truncation; the Bayesian analysis of the matrix Langevin distribution on the Stiefel manifold; and Bayesian inference for a nonparametric Gaussian process density model. The latter two are instances of doubly-intractable Markov chain Monte Carlo problems, where evaluating the likelihood is intractable. Our experiments demonstrate superior performance over state-of-the-art sampling algorithms for such problems. PMID:27279660

  16. Self-contained heat rejection module for future spacecraft

    NASA Technical Reports Server (NTRS)

    Fleming, M. L.; Williams, J. L.; Baskett, J. D.; Leach, J. W.

    1975-01-01

    This paper discusses development of a Self-Contained Heat Rejection Module (SHRM) which can be used on a wide variety of future spacecraft launched by the space shuttle orbiter. The SHRM contains radiators which are deployed by a scissor-mechanism and the flow equipment including pumps, accumulator, by-pass valves, and controllers necessary to reject heat from those radiators. Heat transfer between SHRM and the parent vehicle is effected by a contact heat exchanger. This device provides heat transfer between two separate flow loops through a mechanical connection. This approach reduces the time required to attach the SHRM to the payload, and increases the reliability of the SHRM flow loop since breaking into the fluid system in the field is not required. The SHRM concept also includes a refrigeration system to increase heat rejection capacity in adverse environments, or to provide for a lower return temperature, down to -23 C.

  17. The mechanisms of rejection in solid organ transplantation.

    PubMed

    Cozzi, Emanuele; Colpo, Anna; De Silvestro, Giustina

    2017-08-01

    Organ transplantation represents the preferred treatment option for many patients in terminal organ failure. The half-life of transplanted organs, however, is still far from being satisfactory with the vast majority of the organs failing within the first two decades following transplantation. At this stage, it has become apparent that rejection (prevalently mediated by humoral events) remains the primary cause of graft loss after the first year. In this light, studies are underway to better comprehend the immune events underlying graft rejection and novel immunosuppressive strategies are being explored. In this context, therapeutic apheresis techniques, that include therapeutic plasma exchange (TPE), immunoadsorption (IA) and extracorporeal photochemotherapy (ECP), represent an important adjunct in the current immunosuppressive armamentarium. This article briefly reviews our current understanding of the immune process underlying rejection of a solid organ transplant and describes the principal areas of application of therapeutic apheresis techniques in transplantation. Copyright © 2017. Published by Elsevier Ltd.

  18. Active disturbance rejection control for fractional-order system.

    PubMed

    Li, Mingda; Li, Donghai; Wang, Jing; Zhao, Chunzhe

    2013-05-01

    Fractional-order proportional-integral (PI) and proportional-integral-derivative (PID) controllers are the most commonly used controllers in fractional-order systems. However, this paper proposes a simple integer-order control scheme for fractional-order system based on active disturbance rejection method. By treating the fractional-order dynamics as a common disturbance and actively rejecting it, active disturbance rejection control (ADRC) can achieve the desired response. External disturbance, sensor noise, and parameter disturbance are also estimated using extended state observer. The ADRC stability of rational-order model is analyzed. Simulation results on three typical fractional-order systems are provided to demonstrate the effectiveness of the proposed method.

  19. Changes in the action potential and transient outward potassium current in cardiomyocytes during acute cardiac rejection in rats

    PubMed Central

    Luo, Wenqi; Jia, Yixin; Zheng, Shuai; Li, Yan; Han, Jie

    2017-01-01

    Background Acute cardiac rejection contributes to the changes in the electrophysiological properties of grafted hearts. However, the electrophysiological changes of cardiomyocytes during acute cardiac rejection are still unknown. An understanding of the electrophysiological mechanisms of cardiomyocytes could improve the diagnosis and treatment of acute cardiac rejection. So it is important to characterize the changes in the action potential (AP) and the transient outward potassium current (Ito) in cardiomyocytes during acute cardiac rejection. Methods Heterotopic heart transplantation was performed in allogeneic [Brown Norway (BN)-to-Lewis] and isogeneic (BN-to-BN) rats. Twenty models were established in each group. Ten recipients were sacrificed at the 2nd day and the other ten recipients were sacrificed at the 4th day after the operation in each group. Histopathological examinations of the grafted hearts were performed in half of the recipients in each group randomly. The other half of the grafted hearts were excised rapidly and enzymatically dissociated to obtain single cardiomyocytes. The AP and Ito current were recorded using the whole cell patch-clamp technique. Results Forty grafted hearts were successfully harvested and used in experiments. Histologic examination showed mild rejection at the 2nd day and moderate rejection at the 4th day in the allogeneic group after cardiac transplantation, while no evidence of histologic lesions of rejection were observed in the isogeneic group. Compared with the isogeneic group, the action potential duration (APD) of cardiomyocytes in the allogeneic group was significantly prolonged (APD90 was 49.28±5.621 mV in the isogeneic group and 88.08±6.445 mV in the allogeneic group at the 2nd day, P=0.0016; APD90 was 59.34±5.183 mV in the isogeneic group and 104.0±9.523 mV in the allogeneic group at the 4th day, P=0.0064). The current density of Ito was significantly decreased at the 4th day after cardiac transplantation

  20. Graft rejection by cytolytic T cells. Specificity of the effector mechanism in the rejection of allogeneic marrow

    SciTech Connect

    Nakamura, H.; Gress, R.E. )

    1990-02-01

    Cellular effector mechanisms of allograft rejection remain incompletely described. Characterizing the rejection of foreign-marrow allografts rather than solid-organ grafts has the advantage that the cellular composition of the marrow graft, as a single cell suspension, can be altered to include cellular components with differing antigen expression. Rejection of marrow grafts is sensitive to lethal doses of radiation in the mouse but resistant to sublethal levels of radiation. In an effort to identify cells mediating host resistance, lymphocytes were isolated and cloned from spleens of mice 7 days after sublethal TBI (650 cGy) and inoculation with allogeneic marrow. All clones isolated were cytolytic with specificity for MHC encoded gene products of the allogeneic marrow donor. When cloned cells were transferred in vivo into lethally irradiated (1025 cGy) recipients unable to reject allogeneic marrow, results utilizing splenic 125IUdR uptake indicated that these MHC-specific cytotoxic clones could suppress marrow proliferation. In order to characterize the effector mechanism and the ability of the clones to affect final engraftment, double donor chimeras were constructed so that 2 target cell populations differing at the MHC from each other and from the host were present in the same marrow allograft. Results directly demonstrated an ability of CTL of host MHC type to mediate graft rejection and characterized the effector mechanism as one with specificity for MHC gene products.

  1. Autoantibodies to Vimentin Cause Accelerated Rejection of Cardiac Allografts

    PubMed Central

    Mahesh, Balakrishnan; Leong, Hon-Sing; McCormack, Ann; Sarathchandra, Padmini; Holder, Angela; Rose, Marlene L.

    2007-01-01

    Autoimmune responses to vimentin occur after solid organ transplantation, but their pathogenic effects are unclear. The aim of these studies was to investigate the effects of vimentin preimmunization on allogeneic and isografted hearts in a murine transplant model. Immunization of C57BL/6 mice with murine vimentin in complete Freund’s adjuvant resulted in anti-vimentin antibodies and vimentin-reactive Th-1 cells. Transplantation of 129/sv hearts into vimentin-immunized C57BL/6 recipients resulted in accelerated rejection (8.4 ± 1.5 days; n = 18), compared with hen egg lysozyme-immunized C57BL/6 (13.3 ± 2.2 days; n = 10; P < 0.0001, log-rank test). In contrast, isografts continued to beat beyond 90 days. Immunohistochemical analysis of allografts from vimentin/complete Freund’s adjuvant mice demonstrated increased numbers of T cells and enhanced microvascular deposition of C3d, CD41, and P-selectin compared with controls. Antibodies were necessary for accelerated rejection, shown by the fact that vimentin-immunized B-cell-deficient IgH6 mice did not show accelerated rejection of 129/sv allografts, but rejection was restored by adoptive transfer of serum containing anti-vimentin antibodies. Eluates from donor hearts placed in vimentin/complete Freund’s adjuvant recipients contained anti-vimentin antibodies, shown by Western blotting. Confocal imaging of rejected hearts demonstrated presence of vimentin and C3d on apoptosed leukocytes, endothelial cells, and platelet/leukocyte conjugates. These results demonstrate that autoantibodies to vimentin, in conjunction with the alloimmune response, have a pathogenic role in allograft rejection. PMID:17392180

  2. SPI instrumental background characteristics

    NASA Astrophysics Data System (ADS)

    Jean, P.; Vedrenne, G.; Roques, J. P.; Schönfelder, V.; Teegarden, B. J.; von Kienlin, A.; Knödlseder, J.; Wunderer, C.; Skinner, G. K.; Weidenspointner, G.; Attié, D.; Boggs, S.; Caraveo, P.; Cordier, B.; Diehl, R.; Gros, M.; Leleux, P.; Lichti, G. G.; Kalemci, E.; Kiener, J.; Lonjou, V.; Mandrou, P.; Paul, Ph.; Schanne, S.; von Ballmoos, P.

    2003-11-01

    In its space environment the INTEGRAL observatory is subject to an intense irradiation by energetic cosmic-ray particles that leads, via nuclear interactions with the telescope and spacecraft materials, to an important background of false events. In this paper we present the characteristics of the instrumental background that is observed in the spectrometer SPI (SPectrometer of INTEGRAL). We explain the tuning that has been performed on the parameters of the anticoincidence system in order to optimise the telescope sensitivity over the full energy range. Temporal variations of the instrumental background are discussed and methods are proposed that allow for their modelling in first order. Based on observations with INTEGRAL, an ESA project with instruments and science data centre funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Switzerland, Spain), Czech Republic and Poland, and with the participation of Russia and the USA.

  3. Background suppression in the Edelweiss-III experiment

    SciTech Connect

    Navick, X.-F. [CEA Collaboration: EDELWEISS Collaboration

    2013-08-08

    In dark matter WIMP searches the neutron shielding plays a crucial role in attenuating neutron flux and hence, suppressing nuclear recoil event rate - one of the key background mimicking WIMP interactions. The transition from EDELWEISS-II to EDELWEISS-III with 40 detectors with increased mass and improved background rejection has required the modification of the neutron shielding. In this paper we describe the new neutron shielding design and give an estimate of the expected neutron rate in comparison with the previous stage of the experiment.

  4. The Cosmic Background Explorer

    NASA Technical Reports Server (NTRS)

    Gulkis, Samuel; Lubin, Philip M.; Meyer, Stephan S.; Silverberg, Robert F.

    1990-01-01

    The Cosmic Background Explorer (CBE), NASA's cosmological satellite which will observe a radiative relic of the big bang, is discussed. The major questions connected to the big bang theory which may be clarified using the CBE are reviewed. The satellite instruments and experiments are described, including the Differential Microwave Radiometer, which measures the difference between microwave radiation emitted from two points on the sky, the Far-Infrared Absolute Spectrophotometer, which compares the spectrum of radiation from the sky at wavelengths from 100 microns to one cm with that from an internal blackbody, and the Diffuse Infrared Background Experiment, which searches for the radiation from the earliest generation of stars.

  5. Cosmic Tachyon Background Radiation

    NASA Astrophysics Data System (ADS)

    Tomaschitz, Roman

    The equilibrium statistical mechanics of a background radiation of superluminal particles is investigated, based on a vectorial wave equation for tachyons of the Proca type. The partition function, the spectral energy density, and the various thermodynamic variables of an ideal Bose gas of tachyons in an open Robertson-Walker cosmology are derived. The negative mass square in the wave equation changes the frequency scaling in the Rayleigh-Jeans law, and there are also significant changes in the low temperature regime as compared to the microwave background, in particular in the caloric and thermal equations of state.

  6. Inertial-space disturbance rejection for space-based manipulators

    NASA Technical Reports Server (NTRS)

    Holt, Kevin; Desrochers, Alan A.

    1993-01-01

    The implementation of a disturbance rejection controller for a 6-DOF PUMA manipulator mounted on a 3-DOF platform was described. A control algorithm is designed to track the desired position and attitude of the end-effector in inertial space, subject to unknown disturbances in the platform axes. Experimental results are presented for step, sinusoidal, and random disturbances in the platform rotational axis and in the neighborhood of kinematic singularities. Robotic manipulators were proposed as a means of reducing the amount of extra vehicular activity time required for space station assembly and maintenance. The proposed scenario involves a robotic manipulator attached to some mobile platform, such as a spacecraft, satellite, or the space station itself. Disturbances in the platform position and attitude may prevent the manipulator from successfully completing the task. The possibility of using the manipulator to compensate for platform disturbances was explored. The problem of controlling a robotic manipulator on a mobile platform has received considerable attention in the past few years. Joshi and Desrochers designed a nonlinear feedback control law to carry out tasks (with respect to the robot base frame) in the presence of roll, pitch and yaw disturbances in the platform axes. Dubowsky, Vance, and Torres proposed a time-optimal planning algorithm for a robotic manipulator mounted on a spacecraft, subject to saturation limits in the attitude control reaction jets. Papadopoulos and Dubowsky developed a general framework for analyzing the control of free-floating space manipulator systems. Most recently, Torres and Dubowsky have presented a technique called the enhanced disturbance map to find manipulator trajectories that reduce the effect of disturbances in the spacecraft position and attitude. One common assumption in the literature is that the disturbance signal is exactly known. If this is the case, then the end-effector location can be calculated without

  7. Solar dynamic organic Rankine cycle heat rejection system simulation

    NASA Technical Reports Server (NTRS)

    Havens, V. N.; Ragaller, D. R.; Namkoong, D.

    1987-01-01

    The use of a rotary fluid management device (RFMD) and shear flow condenser for two-phase fluid management in microgravity organic Rankine cycle (ORC) applications is examined. A prototype of the proposed Space Station ORC heat rejection system was constructed to evaluate the performance of the inventory control method. The design and operation of the RFMD, shear flow condenser, and inventory control fluid accumulator are described. A schematic diagram of the ORC, RFMD, and condenser, and a functional diagram of the heat rejection system for the ORC are presented.

  8. Brine rejection from freezing salt solutions: a molecular dynamics study.

    PubMed

    Vrbka, Lubos; Jungwirth, Pavel

    2005-09-30

    The atmospherically and technologically very important process of brine rejection from freezing salt solutions is investigated with atomic resolution using molecular dynamics simulations. The present calculations allow us to follow the motion of each water molecule and salt ion and to propose a microscopic mechanism of brine rejection, in which a fluctuation (reduction) of the ion density in the vicinity of the ice front is followed by the growth of a new ice layer. The presence of salt slows down the freezing process, which leads to the formation of an almost neat ice next to a disordered brine layer.

  9. Method and apparatus for analog pulse pile-up rejection

    DOEpatents

    De Geronimo, Gianluigi

    2014-11-18

    A method and apparatus for pulse pile-up rejection are disclosed. The apparatus comprises a delay value application constituent configured to receive a threshold-crossing time value, and provide an adjustable value according to a delay value and the threshold-crossing time value; and a comparison constituent configured to receive a peak-occurrence time value and the adjustable value, compare the peak-occurrence time value with the adjustable value, indicate pulse acceptance if the peak-occurrence time value is less than or equal to the adjustable value, and indicate pulse rejection if the peak-occurrence time value is greater than the adjustable value.

  10. Solar dynamic organic Rankine cycle heat rejection system simulation

    NASA Technical Reports Server (NTRS)

    Havens, V. N.; Ragaller, D. R.; Namkoong, D.

    1987-01-01

    The use of a rotary fluid management device (RFMD) and shear flow condenser for two-phase fluid management in microgravity organic Rankine cycle (ORC) applications is examined. A prototype of the proposed Space Station ORC heat rejection system was constructed to evaluate the performance of the inventory control method. The design and operation of the RFMD, shear flow condenser, and inventory control fluid accumulator are described. A schematic diagram of the ORC, RFMD, and condenser, and a functional diagram of the heat rejection system for the ORC are presented.

  11. Learning biases underlying individual differences in sensitivity to social rejection

    PubMed Central

    Olsson, Andreas; Carmona, Susanna; Downey, Geraldine; Bolger, Niall; Ochsner, Kevin N.

    2014-01-01

    People vary greatly in their dispositions to anxiously expect, readily perceive, and strongly react to social rejection (rejection sensitivity, RS) with implications for social functioning and health. Here, we examined how RS influences learning about social threat. Using a classical fear conditioning task, we established that high as compared to low (HRS vs. LRS) individuals displayed a resistance to extinction of the conditioned response to angry faces, but not to neutral faces or non-social stimuli. Our findings suggest that RS biases the flexible updating of acquired expectations for threat, which helps to explain how RS operates as a self-fulfilling prophecy. PMID:23914767

  12. Method and apparatus for analog pulse pile-up rejection

    DOEpatents

    De Geronimo, Gianluigi

    2013-12-31

    A method and apparatus for pulse pile-up rejection are disclosed. The apparatus comprises a delay value application constituent configured to receive a threshold-crossing time value, and provide an adjustable value according to a delay value and the threshold-crossing time value; and a comparison constituent configured to receive a peak-occurrence time value and the adjustable value, compare the peak-occurrence time value with the adjustable value, indicate pulse acceptance if the peak-occurrence time value is less than or equal to the adjustable value, and indicate pulse rejection if the peak-occurrence time value is greater than the adjustable value.

  13. Detection of Donor-Derived Microparticles in the Peripheral Blood of a Hand Transplant Recipient During Rejection

    PubMed Central

    Kim, Joseph Y.; Kelesidis, Theodoros; Yang, Otto O.

    2017-01-01

    Background Microparticles (MPs) are released from the plasma membrane of activated or dying cells and bear surface molecules from those cells. We examined whether donor-derived MPs in the peripheral blood of the recipient could serve as a marker of tissue damage due to rejection of a transplanted hand. Methods Platelet-free plasma from the recipient of the transplanted hand was analyzed for MPs bearing the donor-specific HLA molecule A*02 using flow cytometry. Rejection status of the transplanted hand was monitored by histopathology of skin punch biopsies. Results Donor-specific MPs expressing HLA A*02 were quantifiable in the peripheral blood of the recipient. Levels of these MPs increased with worsening rejection of the transplanted hand. Conclusions These findings demonstrate the ability to detect donor specific MPs through staining of graft cell-specific HLA and promote further investigation into the potential utility of flow cytometry for donor-derived MPs as a noninvasive tool to assess rejection in solid organ transplantation patients.

  14. Background Model for the Majorana Demonstrator

    SciTech Connect

    Cuesta, C.; Abgrall, N.; Aguayo, Estanislao; Avignone, Frank T.; Barabash, Alexander S.; Bertrand, F.; Boswell, M.; Brudanin, V.; Busch, Matthew; Byram, D.; Caldwell, A. S.; Chan, Yuen-Dat; Christofferson, Cabot-Ann; Combs, Dustin C.; Detwiler, Jason A.; Doe, Peter J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, S. R.; Fast, James E.; Finnerty, P.; Fraenkle, Florian; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guiseppe, Vincente; Gusev, K.; Hallin, A. L.; Hazama, R.; Hegai, A.; Henning, Reyco; Hoppe, Eric W.; Howard, Stanley; Howe, M. A.; Keeter, K.; Kidd, M. F.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; Laferriere, Brian D.; Leon, Jonathan D.; Leviner, L.; Loach, J. C.; MacMullin, J.; MacMullin, S.; Martin, R. D.; Meijer, S. J.; Mertens, S.; Nomachi, Masaharu; Orrell, John L.; O'Shaughnessy, C.; Overman, Nicole R.; Phillips, D.; Poon, Alan; Pushkin, K.; Radford, D. C.; Rager, J.; Rielage, Keith; Robertson, R. G. H.; Romero-Romero, E.; Ronquest, M. C.; Schubert, Alexis G.; Shanks, B.; Shima, T.; Shirchenko, M.; Snavely, Kyle J.; Snyder, N.; Suriano, Anne-Marie; Thompson, J.; Timkin, V.; Tornow, Werner; Trimble, J. E.; Varner, R. L.; Vasilyev, Sergey; Vetter, Kai; Vorren, Kris R.; White, Brandon R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Young, A.; Yu, Chang-Hong; Yumatov, Vladimir

    2015-06-01

    The Majorana Collaboration is constructing a prototype system containing 40 kg of HPGe detectors to demonstrate the feasibility and potential of a future tonne-scale experiment to search for neutrinoless double-beta (0v BB) decay in 76Ge. In view of the requirement that the next generation of tonne-scale Ge-based 0vBB-decay experiment be capable of probing the neutrino mass scale in the inverted-hierarchy region, a major goal of theMajorana Demonstrator is to demonstrate a path forward to achieving a background rate at or below 1 cnt/(ROI-t-y) in the 4 keV region of interest around the Q-value at 2039 keV. This goal is pursued through a combination of a significant reduction of radioactive impurities in construction materials with analytical methods for background rejection, for example using powerful pulse shape analysis techniques profiting from the p-type point contact HPGe detectors technology. The effectiveness of these methods is assessed using Geant4 simulations of the different background components whose purity levels are constrained from radioassay measurements.

  15. EXO-200 results and cosmogenic backgrounds

    NASA Astrophysics Data System (ADS)

    Belov, V. A.; EXO-200 collaboration

    2017-01-01

    Status update and recent results from the double beta decay search experiment EXO-200 are presented. Detector is a liquid xenon TPC with charge and light readout located underground in low-background laboratory at 1600 m.w.e. depth. It contains 175 kg of xenon with 80.6% abundance of 136Xe, which acts as both the decaying nucleus and detection medium. Detector showed good performance and achieved remarkable results. The detector has demonstrated excellent energy resolution and background rejection capabilities and has set a lower limit on the 0νββ-decay half-life of 1.1 × 1025 years at 90% C.L. in early 2014. The EXO-200 collaboration has since published several papers on experimental backgrounds and searches for rare or exotic processes. After a two-year data interruption, EXO-200 is now back online with significant hardware improvements, including a radon reduction air system and a front end electronics upgrade for better energy resolution.

  16. Thermal control systems for low-temperature heat rejection on a lunar base

    NASA Technical Reports Server (NTRS)

    Sridhar, K. R.; Gottmann, Matthias

    1992-01-01

    In this report, Rankine-cycle heat pumps and absorption heat pumps (ammonia-water and lithium bromide-water) have been analyzed and optimized for a lunar base cooling load of 100 kW. For the Rankine cycle, a search of several commonly used commercial refrigerants provided R11 and R717 as possible working fluids. Hence, the Rankine-cycle analysis has been performed for both R11 and R717. Two different configurations were considered for the system--one in which the heat pump is directly connected to the rejection loop and another in which a heat exchanger connects the heat pump to the rejection loop. For a marginal increase in mass, the decoupling of the rejection loop and the radiator from the heat pump provides greater reliability of the system and better control. Hence, the decoupled system is the configuration of choice. The optimal TCS mass for a 100 kW cooling load at 270 K was 5940 kg at a radiator temperature of 362 K. R11 was the working fluid in the heat pump, and R717 was the transport fluid in the rejection loop. Two TCS's based on an absorption-cycle heat pump were considered, one with an ammonia-water mixture and the other with a lithium bromide-water mixture as the working fluid. A complete cycle analysis was performed for these systems. The system components were approximated as heat exchangers with no internal pressure drop for the mass estimate. This simple approach underpredicts the mass of the systems, but is a good 'optimistic' first approximation to the TCS mass in the absence of reliable component mass data. The mass estimates of the two systems reveal that, in spite of this optimistic estimate, the absorption heat pumps are not competitive with the Rankine-cycle heat pumps. Future work at the systems level will involve similar analyses for the Brayton- and Stirling-cycle heat pumps. The analyses will also consider the operation of the pump under partial-load conditions. On the component level, a capillary evaporator will be designed, built

  17. Berkeley Low Background Facility

    NASA Astrophysics Data System (ADS)

    Thomas, K. J.; Smith, A. R.; Poon, A. W. P.; Chan, Y. D.; Norman, E. B.; Lesko, K. T.

    2015-08-01

    The Berkeley Low Background Facility (BLBF) at Lawrence Berkeley National Laboratory (LBNL) in Berkeley, California provides low background gamma spectroscopy services to a wide array of experiments and projects. The analysis of samples takes place within two unique facilities; locally within a carefully-constructed, low background laboratory on the surface at LBNL and at the Sanford Underground Research Facility (SURF) in Lead, SD. These facilities provide a variety of gamma spectroscopy services to low background experiments primarily in the form of passive material screening for primordial radioisotopes (U, Th, K) or common cosmogenic/anthropogenic products; active screening via neutron activation analysis for U,Th, and K as well as a variety of stable isotopes; and neutron flux/beam characterization measurements through the use of monitors. A general overview of the facilities, services, and sensitivities will be presented. Recent activities and upgrades will also be described including an overview of the recently installed counting system at SURF (recently relocated from Oroville, CA in 2014), the installation of a second underground counting station at SURF in 2015, and future plans. The BLBF is open to any users for counting services or collaboration on a wide variety of experiments and projects.

  18. Building Background Knowledge

    ERIC Educational Resources Information Center

    Fisher, Douglas; Ross, Donna; Grant, Maria

    2010-01-01

    Too often, students enter our classrooms with insufficient knowledge of physical science. As a result, they have a difficult time understanding content in texts, lectures, and laboratory activities. This lack of background knowledge can have an impact on their ability to ask questions and wonder--both key components of inquiry. In this article,…

  19. Berkeley Low Background Facility

    SciTech Connect

    Thomas, K. J.; Norman, E. B.; Smith, A. R.; Poon, A. W. P.; Chan, Y. D.; Lesko, K. T.

    2015-08-17

    The Berkeley Low Background Facility (BLBF) at Lawrence Berkeley National Laboratory (LBNL) in Berkeley, California provides low background gamma spectroscopy services to a wide array of experiments and projects. The analysis of samples takes place within two unique facilities; locally within a carefully-constructed, low background laboratory on the surface at LBNL and at the Sanford Underground Research Facility (SURF) in Lead, SD. These facilities provide a variety of gamma spectroscopy services to low background experiments primarily in the form of passive material screening for primordial radioisotopes (U, Th, K) or common cosmogenic/anthropogenic products; active screening via neutron activation analysis for U,Th, and K as well as a variety of stable isotopes; and neutron flux/beam characterization measurements through the use of monitors. A general overview of the facilities, services, and sensitivities will be presented. Recent activities and upgrades will also be described including an overview of the recently installed counting system at SURF (recently relocated from Oroville, CA in 2014), the installation of a second underground counting station at SURF in 2015, and future plans. The BLBF is open to any users for counting services or collaboration on a wide variety of experiments and projects.

  20. Nonthermal cosmic neutrino background

    NASA Astrophysics Data System (ADS)

    Chen, Mu-Chun; Ratz, Michael; Trautner, Andreas

    2015-12-01

    We point out that, for Dirac neutrinos, in addition to the standard thermal cosmic neutrino background (C ν B ), there could also exist a nonthermal neutrino background with comparable number density. As the right-handed components are essentially decoupled from the thermal bath of standard model particles, relic neutrinos with a nonthermal distribution may exist until today. The relic density of the nonthermal (nt) background can be constrained by the usual observational bounds on the effective number of massless degrees of freedom Neff and can be as large as nν nt≲0.5 nγ. In particular, Neff can be larger than 3.046 in the absence of any exotic states. Nonthermal relic neutrinos constitute an irreducible contribution to the detection of the C ν B and, hence, may be discovered by future experiments such as PTOLEMY. We also present a scenario of chaotic inflation in which a nonthermal background can naturally be generated by inflationary preheating. The nonthermal relic neutrinos, thus, may constitute a novel window into the very early Universe.

  1. Foregrounding the Background.

    ERIC Educational Resources Information Center

    Robbins, Bruce

    1998-01-01

    Argues that when introductory activities to the classics begin with background information, it can upstage or confine the life of the story, and shows little faith in the students as readers or in the literature itself. Suggests sometimes letting the literature begin, and then helping students make sense of it. Discusses examples from "To Kill a…

  2. China: Background Notes Series.

    ERIC Educational Resources Information Center

    Reams, Joanne Reppert

    Concise background information on the People's Republic of China is provided. The publication begins with a profile of the country, outlining the people, geography, economy, and membership in international organizations. The bulk of the document then discusses in more detail China's people, geography, history, government, education, economy, and…

  3. Building Background Knowledge

    ERIC Educational Resources Information Center

    Fisher, Douglas; Ross, Donna; Grant, Maria

    2010-01-01

    Too often, students enter our classrooms with insufficient knowledge of physical science. As a result, they have a difficult time understanding content in texts, lectures, and laboratory activities. This lack of background knowledge can have an impact on their ability to ask questions and wonder--both key components of inquiry. In this article,…

  4. Disappearance of T Cell-Mediated Rejection Despite Continued Antibody-Mediated Rejection in Late Kidney Transplant Recipients.

    PubMed

    Halloran, Philip F; Chang, Jessica; Famulski, Konrad; Hidalgo, Luis G; Salazar, Israel D R; Merino Lopez, Maribel; Matas, Arthur; Picton, Michael; de Freitas, Declan; Bromberg, Jonathan; Serón, Daniel; Sellarés, Joana; Einecke, Gunilla; Reeve, Jeff

    2015-07-01

    The prevalent renal transplant population presents an opportunity to observe the adaptive changes in the alloimmune response over time, but such studies have been limited by uncertainties in the conventional biopsy diagnosis of T cell-mediated rejection (TCMR) and antibody-mediated rejection (ABMR). To circumvent these limitations, we used microarrays and conventional methods to investigate rejection in 703 unselected biopsies taken 3 days to 35 years post-transplant from North American and European centers. Using conventional methods, we diagnosed rejection in 205 biopsy specimens (28%): 67 pure TCMR, 110 pure ABMR, and 28 mixed (89 designated borderline). Using microarrays, we diagnosed rejection in 228 biopsy specimens (32%): 76 pure TCMR, 124 pure ABMR, and 28 mixed (no borderline). Molecular assessment confirmed most conventional diagnoses (agreement was 90% for TCMR and 83% for ABMR) but revealed some errors, particularly in mixed rejection, and improved prediction of failure. ABMR was strongly associated with increased graft loss, but TCMR was not. ABMR became common in biopsy specimens obtained >1 year post-transplant and continued to appear in all subsequent intervals. TCMR was common early but progressively disappeared over time. In 108 biopsy specimens obtained 10.2-35 years post-transplant, TCMR defined by molecular and conventional features was never observed. We conclude that the main cause of kidney transplant failure is ABMR, which can present even decades after transplantation. In contrast, TCMR disappears by 10 years post-transplant, implying that a state of partial adaptive tolerance emerges over time in the kidney transplant population.

  5. Maternal Predictors of Rejecting Parenting and Early Adolescent Antisocial Behavior

    ERIC Educational Resources Information Center

    Trentacosta, Christopher J.; Shaw, Daniel S.

    2008-01-01

    The present study examined relations among maternal psychological resources, rejecting parenting, and early adolescent antisocial behavior in a sample of 231 low-income mothers and their sons with longitudinal assessments from age 18 months to 12 years. The maternal resources examined were age at first birth, aggressive personality, and empathy.…

  6. From Acceptance to Rejection: Food Contamination in the Classroom.

    ERIC Educational Resources Information Center

    Rajecki, D. W.

    1989-01-01

    Describes a classroom exercise to explain design and measurement principles in methodology and statistics courses. This demonstration which involves measurement of a shift from food acceptance to food rejection produces meaningful data sets. The realism of the exercise gives students a view of problems that emerge in research. (KO)

  7. Examining Appearance-Based Rejection Sensitivity during Early Adolescence

    ERIC Educational Resources Information Center

    Bowker, Julie C.; Thomas, Katelyn K.; Spencer, Sarah V.; Park, Lora E.

    2013-01-01

    The present study of 150 adolescents ("M" age = 13.05 years) examined the associations between appearance-based rejection sensitivity (Appearance-RS) and psychological adjustment during early adolescence, and evaluated three types of other-gender peer experiences (other-gender friendship, peer acceptance, and romantic relationships) as…

  8. Solar collector apparatus having increased energy rejection during stagnation

    DOEpatents

    Moore, S.W.

    1981-01-16

    An active solar collector having increased energy rejection during stagnation is disclosed. The collector's glazing is brought into substantial contact with absorber during stagnation to increase re-emittance and thereby to maintan lower temperatures when the collector is not in operation.

  9. Solar collector apparatus having increased energy rejection during stagnation

    DOEpatents

    Moore, Stanley W.

    1983-07-12

    The disclosure relates to an active solar collector having increased energy rejection during stagnation. The collector's glazing is brought into substantial contact with absorber during stagnation to increase re-emittance and thereby to maintain lower temperatures when the collector is not in operation.

  10. Pretransplant identification of acute rejection risk following kidney transplantation.

    PubMed

    Lebranchu, Yvon; Baan, Carla; Biancone, Luigi; Legendre, Christophe; Morales, José Maria; Naesens, Maarten; Thomusch, Oliver; Friend, Peter

    2014-02-01

    Lack of an accepted definition for 'high immunological risk' hampers individualization of immunosuppressive therapy after kidney transplantation. For recipient-related risk factors for acute rejection, the most compelling evidence points to younger age and African American ethnicity. Recipient gender, body mass, previous transplantation, and concomitant infection or disease do not appear to be influential. Deceased donation now has only a minor effect on rejection risk, but older donor age remains a significant predictor. Conventional immunological markers (human leukocyte antigen [HLA] mismatching, pretransplant anti-HLA alloantibodies, and panel reactive antibodies) are being reassessed in light of growing understanding about the role of donor-specific antibodies (DSA). At the time of transplant, delayed graft function is one of the most clear-cut risk factors for acute rejection. Extended cold ischemia time (≥ 24 h) may also play a contributory role. While it is not yet possible to establish conclusively the relative contribution of different risk factors for acute rejection after kidney transplantation, the available data point to variables that should be taken into account at the time of transplant. Together, these offer a realistic basis for planning an appropriate immunosuppression regimen in individual patients.

  11. Peer Rejection Cues Induce Cardiac Slowing after Transition into Adolescence

    ERIC Educational Resources Information Center

    Gunther Moor, Bregtje; Bos, Marieke G. N.; Crone, Eveline A.; van der Molen, Maurits W.

    2014-01-01

    The present study examined developmental and gender differences in sensitivity to peer rejection across the transition into adolescence by examining beat-by-beat heart rate responses. Children between the ages of 8 and 14 years were presented with unfamiliar faces of age-matched peers and were asked to predict whether they would be liked by the…

  12. Project Zero Reject Manual: Strategies in Child Find.

    ERIC Educational Resources Information Center

    Gilliam, Deborah F. Carpenter; And Others

    The report describes Project Zero Reject, a cooperative effort between the Dallas (TX) Independent School District and the Dallas County Mental Health Mental Retardation Center to locate handicapped children not receiving educational services and to develop a computerized information system for planning regarding these children. Awareness efforts…

  13. Compact filtering monopole patch antenna with dual-band rejection.

    PubMed

    Kim, Sun-Woong; Choi, Dong-You

    2016-01-01

    In this paper, a compact ultra-wideband patch antenna with dual-band rejection is proposed. The proposed antenna filters 3.3-3.8 GHz WiMAX and 5.15-5.85 GHz WLAN by respectively rejecting these bands through a C-shaped slit and a λg/4 resonator. The λg/4 resonator is positioned as a pair, centered around the microstrip line, and a C-type slit is inserted into an elliptical patch. The impedance bandwidth of the proposed antenna is 2.9-9.3 GHz, which satisfies the bandwidth for ultra-wideband communication systems. Further, the proposed antenna provides dual-band rejection at two bands: 3.2-3.85 and 4.7-6.03 GHz. The radiation pattern of the antenna is omnidirectional, and antenna gain is maintained constantly while showing -8.4 and -1.5 dBi at the two rejected bands, respectively.

  14. Heat Rejection from a Variable Conductance Heat Pipe Radiator Panel

    NASA Technical Reports Server (NTRS)

    Jaworske, D. A.; Gibson, M. A.; Hervol, D. S.

    2012-01-01

    A titanium-water heat pipe radiator having an innovative proprietary evaporator configuration was evaluated in a large vacuum chamber equipped with liquid nitrogen cooled cold walls. The radiator was manufactured by Advanced Cooling Technologies, Inc. (ACT), Lancaster, PA, and delivered as part of a Small Business Innovative Research effort. The radiator panel consisted of five titanium-water heat pipes operating as thermosyphons, sandwiched between two polymer matrix composite face sheets. The five variable conductance heat pipes were purposely charged with a small amount of non-condensable gas to control heat flow through the condenser. Heat rejection was evaluated over a wide range of inlet water temperature and flow conditions, and heat rejection was calculated in real-time utilizing a data acquisition system programmed with the Stefan-Boltzmann equation. Thermography through an infra-red transparent window identified heat flow across the panel. Under nominal operation, a maximum heat rejection value of over 2200 Watts was identified. The thermal vacuum evaluation of heat rejection provided critical information on understanding the radiator s performance, and in steady state and transient scenarios provided useful information for validating current thermal models in support of the Fission Power Systems Project.

  15. Project Zero Reject Manual: Strategies in Child Find.

    ERIC Educational Resources Information Center

    Gilliam, Deborah F. Carpenter; And Others

    The report describes Project Zero Reject, a cooperative effort between the Dallas (TX) Independent School District and the Dallas County Mental Health Mental Retardation Center to locate handicapped children not receiving educational services and to develop a computerized information system for planning regarding these children. Awareness efforts…

  16. Examining Appearance-Based Rejection Sensitivity during Early Adolescence

    ERIC Educational Resources Information Center

    Bowker, Julie C.; Thomas, Katelyn K.; Spencer, Sarah V.; Park, Lora E.

    2013-01-01

    The present study of 150 adolescents ("M" age = 13.05 years) examined the associations between appearance-based rejection sensitivity (Appearance-RS) and psychological adjustment during early adolescence, and evaluated three types of other-gender peer experiences (other-gender friendship, peer acceptance, and romantic relationships) as…

  17. Chlorine-resistant composite membranes with high organic rejection

    DOEpatents

    McCray, Scott B.; Friesen, Dwayne T.; Barss, Robert P.; Nelson, Leslie D.

    1996-01-01

    A method for making a chlorine-resistant composite polyamide membrane having high organic rejection, the essential step of which comprises treating a conventional composite membrane with an acyl halide. The novel membrane is especially suitable for the treatment of water containing chlorine or lower molecular weight organic compounds.

  18. Peer Rejection Cues Induce Cardiac Slowing after Transition into Adolescence

    ERIC Educational Resources Information Center

    Gunther Moor, Bregtje; Bos, Marieke G. N.; Crone, Eveline A.; van der Molen, Maurits W.

    2014-01-01

    The present study examined developmental and gender differences in sensitivity to peer rejection across the transition into adolescence by examining beat-by-beat heart rate responses. Children between the ages of 8 and 14 years were presented with unfamiliar faces of age-matched peers and were asked to predict whether they would be liked by the…

  19. 48 CFR 14.404-2 - Rejection of individual bids.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Rejection of individual bids. 14.404-2 Section 14.404-2 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION... means not barred by 41 U.S.C. 15 or 31 U.S.C. 3727....

  20. Rejected Manuscripts in Publishers' Archives: Legal Rights and Access

    ERIC Educational Resources Information Center

    Hamburger, Susan

    2011-01-01

    This article focuses on an analysis of how various archival repositories deal with rejected manuscripts in publishers' archives as part of existing collections and as potential donations, and includes suggestions for ways to provide access while maintaining the author's legal rights. Viewpoints from the journal editor, author, archivist, and…