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Sample records for myography background current

  1. Electrical Impedance Myography: Background, Current State, and Future Directions

    PubMed Central

    Rutkove, Seward B.

    2010-01-01

    Electrical impedance myography (EIM) is a new non-invasive technique for the evaluation of neuromuscular disease that relies upon the application and measurement of high-frequency, low-intensity electrical current. EIM assesses disease-induced changes to muscle’s normal composition and architecture, including myocyte atrophy and loss, edema, reinnervation, and the deposition of endomysial connective tissue and fat. With application of single-frequency electrical current, EIM can be used to help grade the severity of neuromuscular disease. Assessing electrical impedance across a spectrum of applied frequencies and with current flow at multiple orientations relative to the major muscle fiber direction can provide a more complete picture of muscle condition. EIM holds the promise of serving as an indicator of disease status, thus being useful in clinical trials work and in monitoring effectiveness of treatment in individual patients; ultimately, it may also find diagnostic application. Ongoing efforts have been focused on obtaining a deeper understanding of the basic mechanisms of impedance change, studying EIM in a variety of clinical contexts, and further refining the methods of EIM data acquisition and analysis. PMID:19768754

  2. Tanzania: Background and Current Conditions

    DTIC Science & Technology

    2010-12-08

    in parliament. Tanzania continues its pattern of steady real Gross Domestic Product ( GDP ) growth and has a low and stable inflation rate. The...Economist Intelligence Unit predicts real Gross Domestic Product ( GDP ) growth of 7.1% in 2011 and 7.6% in 2012. Tanzania: Background and Current...unity for about 40 years in a region wracked by civil wars, often with ethnic dimensions, in neighboring Rwanda, Burundi , Uganda, the Democratic

  3. Rwanda: Background and Current Developments

    DTIC Science & Technology

    2010-12-07

    1994, the presidents of Rwanda and Burundi , along with several senior government officials, were killed when their plane was shot down as it...agreement in Tanzania, referred to as the Arusha Peace Accords. In April 1994, the presidents of Rwanda and Burundi , along with several senior government...Muslim: 4.6% GDP -Purchasing power parity: $10.13 billion (2009) GDP per capita: $900 (2009) Source: CIA—The World Factbook 2010. Rwanda: Background and

  4. Electrical impedance myography in facioscapulohumeral muscular dystrophy.

    PubMed

    Statland, Jeffrey M; Heatwole, Chad; Eichinger, Katy; Dilek, Nuran; Martens, William B; Tawil, Rabi

    2016-10-01

    In this study we determined the reliability and validity of electrical impedance myography (EIM) in facioscapulohumeral muscular dystrophy (FSHD). We performed a prospective study of EIM on 16 bilateral limb and trunk muscles in 35 genetically defined and clinically affected FSHD patients (reliability testing on 18 patients). Summary scores based on body region were derived. Reactance and phase (50 and 100 kHz) were compared with measures of strength, FSHD disease severity, and functional outcomes. Participants were mostly men, mean age 53.0 years, and included a full range of severity. Limb and trunk muscles showed good to excellent reliability [intraclass correlation coefficients (ICC) 0.72-0.99]. Summary scores for the arm, leg, and trunk showed excellent reliability (ICC 0.89-0.98). Reactance was the most sensitive EIM parameter to a broad range of FSHD disease metrics. EIM is a reliable measure of muscle composition in FSHD that offers the possibility to serially evaluate affected muscles. Muscle Nerve 54: 696-701, 2016. © 2016 Wiley Periodicals, Inc.

  5. Muscle activity characterization by laser Doppler Myography

    NASA Astrophysics Data System (ADS)

    Scalise, Lorenzo; Casaccia, Sara; Marchionni, Paolo; Ercoli, Ilaria; Primo Tomasini, Enrico

    2013-09-01

    Electromiography (EMG) is the gold-standard technique used for the evaluation of muscle activity. This technique is used in biomechanics, sport medicine, neurology and rehabilitation therapy and it provides the electrical activity produced by skeletal muscles. Among the parameters measured with EMG, two very important quantities are: signal amplitude and duration of muscle contraction, muscle fatigue and maximum muscle power. Recently, a new measurement procedure, named Laser Doppler Myography (LDMi), for the non contact assessment of muscle activity has been proposed to measure the vibro-mechanical behaviour of the muscle. The aim of this study is to present the LDMi technique and to evaluate its capacity to measure some characteristic features proper of the muscle. In this paper LDMi is compared with standard superficial EMG (sEMG) requiring the application of sensors on the skin of each patient. sEMG and LDMi signals have been simultaneously acquired and processed to test correlations. Three parameters has been analyzed to compare these techniques: Muscle activation timing, signal amplitude and muscle fatigue. LDMi appears to be a reliable and promising measurement technique allowing the measurements without contact with the patient skin.

  6. The Reliable Replacement Warhead Program: Background and Current Developments

    DTIC Science & Technology

    2007-07-13

    Order Code RL32929 The Reliable Replacement Warhead Program: Background and Current Developments Updated July 13, 2007 Jonathan Medalia Specialist...SUBTITLE The Reliable Replacement Warhead Program: Background and Current Developments 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 The Reliable Replacement Warhead Program: Background

  7. The Reliable Replacement Warhead Program: Background and Current Developments

    DTIC Science & Technology

    2007-06-12

    Order Code RL32929 The Reliable Replacement Warhead Program: Background and Current Developments Updated June 12, 2007 Jonathan Medalia Specialist...SUBTITLE The Reliable Replacement Warhead Program: Background and Current Developments 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 The Reliable Replacement Warhead Program

  8. Comprehensive Nuclear-Test-Ban Treaty: Background and Current Developments

    DTIC Science & Technology

    2008-09-18

    SUBTITLE Comprehensive Nuclear-Test-Ban Treaty: Background and Current Developments 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT ...the ratification of the CTBT. It would be imprudent to tie the hands of a future administration that may have to conduct a test of an element of an...Monitoring Former Soviet Union, excerpt from a report by Russian News Agency ITAR-TASS, September 23, 2005. 15 “Russia Supports CTBT as Key Element of

  9. Comprehensive Nuclear-Test-Ban Treaty: Background and Current Developments

    DTIC Science & Technology

    2008-04-30

    SUBTITLE Comprehensive Nuclear-Test-Ban Treaty: Background and Current Developments 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER...administration that may have to conduct a test of an element of an aging, unmodernized stockpile in order to assure the reliability of the nuclear deterrent force...continued) Soviet Union, excerpt from a report by Russian News Agency ITAR-TASS, September 23, 2005. 15 “Russia Supports CTBT as Key Element of Nuclear Non

  10. Comprehensive Nuclear-Test-Ban Treaty: Background and Current Developments

    DTIC Science & Technology

    2008-05-28

    SUBTITLE Comprehensive Nuclear-Test-Ban Treaty: Background and Current Developments 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...administration that may have to conduct a test of an element of an aging, unmodernized stockpile in order to assure the reliability of the nuclear...Soviet Union, excerpt from a report by Russian News Agency ITAR-TASS, September 23, 2005. 16 “Russia Supports CTBT as Key Element of Nuclear Non

  11. Acoustic myography, electromyography and bite force in the masseter muscle.

    PubMed

    Tortopidis, D; Lyons, M F; Baxendale, R H

    1998-12-01

    Acoustic myography (AMG) offers some advantages over electromyography (EMG) in certain circumstances, but the use of AMG on the jaw-closing muscles has not been fully tested. The purpose of this study was to examine the relationship between AMG, EMG and force in the masseter muscles of nine healthy male subjects. The AMG was recorded using a piezoelectric crystal microphone and the EMG was recorded simultaneously with surface electrodes. Force was recorded between the anterior teeth with a strain-gauge transducer. Analysis showed that Pearson's correlation coefficient was 0.913 for force/AMG and 0.973 for force/EMG in all subjects, indicating a linear relationship between force, AMG and EMG at the four different force levels tested (25-75% of maximum). It is apparent that AMG may be used as an accurate monitor of masseter muscle force production, although some care is required in the technique.

  12. Comprehensive Nuclear-Test-Ban Treaty: Background and Current Developments

    DTIC Science & Technology

    2010-01-06

    Background and Current Developments 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f...administration that may have to conduct a test of an element of an aging, unmodernized stockpile in order to assure the reliability of the nuclear deterrent...State Ellen Tauscher described elements of the Administration’s strategy to win Senate approval of the treaty. “This administration will not attempt

  13. Internal solitary waves propagating through variable background hydrology and currents

    NASA Astrophysics Data System (ADS)

    Liu, Z.; Grimshaw, R.; Johnson, E.

    2017-08-01

    Large-amplitude, horizontally-propagating internal wave trains are commonly observed in the coastal ocean, fjords and straits. They are long nonlinear waves and hence can be modelled by equations of the Korteweg-de Vries type. However, typically they propagate through regions of variable background hydrology and currents, and over variable bottom topography. Hence a variable-coefficient Korteweg-de Vries equation is needed to model these waves. Although this equation is now well-known and heavily used, a term representing non-conservative effects, arising from dissipative or forcing terms in the underlying basic state, has usually been omitted. In particular this term arises when the hydrology varies in the horizontal direction. Our purpose in this paper is to examine the possible significance of this term. This is achieved through analysis and numerical simulations, using both a two-layer fluid model and a re-examination of previous studies of some specific ocean cases.

  14. Mesenteric artery contraction and relaxation studies using automated wire myography.

    PubMed

    Bridges, Lakeesha E; Williams, Cicely L; Pointer, Mildred A; Awumey, Emmanuel M

    2011-09-22

    Proximal resistance vessels, such as the mesenteric arteries, contribute substantially to the peripheral resistance. These small vessels of between 100-400 μm in diameter function primarily in directing blood flow to various organs according to the overall requirements of the body. The rat mesenteric artery has a diameter greater than 100 μm. The myography technique, first described by Mulvay and Halpern(1), was based on the method proposed by Bevan and Osher(2). The technique provides information about small vessels under isometric conditions, where substantial shortening of the muscle preparation is prevented. Since force production and sensitivity of vessels to different agonists is dependent on the extent of stretch, according to active tension-length relation, it is essential to conduct contraction studies under isometric conditions to prevent compliance of the mounting wires. Stainless steel wires are preferred to tungsten wires because of oxidation of the latter, which affects recorded responses(3).The technique allows for the comparison of agonist-induced contractions of mounted vessels to obtain evidence for normal function of vascular smooth muscle cell receptors. We have shown in several studies that isolated mesenteric arteries that are contracted with phenylyephrine relax upon addition of cumulative concentrations of extracellular calcium (Ca(2+)(e;)). The findings led us to conclude that perivascular sensory nerves, which express the G protein-coupled Ca(2+)-sensing receptor (CaR), mediate this vasorelaxation response. Using an automated wire myography method, we show here that mesenteric arteries from Wistar, Dahl salt-sensitive(DS) and Dahl salt-resistant (DR) rats respond differently to Ca(2+)(e;). Tissues from Wistar rats showed higher Ca(2+)-sensitivity compared to those from DR and DS. Reduced CaR expression in mesenteric arteries from DS rats correlates with reduced Ca(2+)(e;)-induced relaxation of isolated, pre-contracted arteries. The data

  15. Recording characteristics of electrical impedance myography needle electrodes.

    PubMed

    Kwon, H; Rutkove, S B; Sanchez, B

    2017-08-21

    Neurologists and physiatrists need improved tools for the evaluation of skeletal muscle condition. Here we evaluate needle electrical impedance myography (EIM), a new minimally invasive approach to determine muscle status that could ultimately become a bedside tool for the assessment of neuromuscular disorders. We design and study the recording characteristics of tetrapolar EIM needle electrodes combining theory and finite-element model simulations. We then use these results to build and pilot in vivo an EIM needle electrode in the rat gastrocnemius muscle ([Formula: see text]). The dielectric properties of muscle are reported (mean  ±  standard deviation). The numerical simulations show that the contribution of subcutaneous fat and muscle tissues to needle EIM data is <3% and >97%, respectively, and the sensed volume is [Formula: see text] cm(3). Apparent resistivity [Formula: see text] [Formula: see text] cm and relative permittivity [Formula: see text] (dimensionless) measured at 10 kHz are in good agreement with in vivo dielectric properties reported in the literature. The results presented show the feasibility of measuring muscle impedivity in vivo using a needle electrode from 10 kHz to 1 MHz. The development of needle EIM technology can open up a new field of study in electrodiagnostic medicine, with potential applications to both disease diagnosis and biomarker assessment of therapy.

  16. Handheld Electrical Impedance Myography Probe for Assessing Carpal Tunnel Syndrome.

    PubMed

    Li, Zhao; Chen, Lingfen; Zhu, Yu; Wei, Qingquan; Liu, Wenwen; Tian, Dong; Yu, Yude

    2017-03-30

    Electrical impedance myography (EIM) is a novel, noninvasive, and painless technique for quantitatively assessing muscle health as well as disease status and progression. The preparatory work for commercial adhesive electrodes used in previous EIM measurements is tedious, as the electrodes need to be cut, repeatedly applied, and removed. Moreover, the electrode distances need to be measured many times. To overcome these problems, we developed a convenient and practical handheld EIM probe for assessing carpal tunnel syndrome (CTS) in the small hand muscles. To reduce the electrode-skin contact impedance (ESCI), the micropillared and microholed stainless steel electrodes (SSEs) contained in the probe were fabricated using a laser processing technique. When covered with saline, these electrodes showed lower ESCIs than a smooth SSE and Ag/AgCl electrode. The probe was shown to have excellent test-retest reproducibility in both healthy subjects and CTS patients, with intraclass correlation coefficients exceeding 0.975. The reactance and phase values of the abductor pollicis brevis (affected muscle) for CTS patients were consistently lower than those for healthy subjects, with a 50-kHz difference of 37.1% (p < 0.001) and 31.0% (p < 0.001), respectively. Further, no significant differences were detected in the case of the abductor digiti minimi (unaffected muscle). These results indicate that EIM has considerable potential for CTS assessment and hence merits further investigation.

  17. The Effect of Subcutaneous Fat on Electrical Impedance Myography: Electrode Configuration and Multi-Frequency Analyses

    PubMed Central

    Li, Le; Li, Xiaoyan; Hu, Huijing; Shin, Henry

    2016-01-01

    This study investigates the impact of the subcutaneous fat layer (SFL) thickness on localized electrical impedance myography (EIM), as well as the effects of different current electrodes, varying in distance and direction, on EIM output. Twenty-three healthy subjects underwent localized multi-frequency EIM on their biceps brachii muscles with a hand-held electrode array. The EIM measurements were recorded under three different configurations: wide (or outer) longitudinal configuration 6.8 cm, narrow (or inner) longitudinal configuration 4.5 cm, and narrow transverse configuration 4.5 cm. Ultrasound was applied to measure the SFL thickness. Coefficients of determination (R2) of three EIM variables (resistance, reactance, and phase) and SFL thickness were calculated. For the longitudinal configuration, the wide distance could reduce the effects of the subcutaneous fat when compared with the narrow distance, but a significant correlation still remained for all three EIM parameters. However, there was no significant correlation between SFL thickness and reactance in the transverse configuration (R2 = 0.0294, p = 0.434). Utilizing a ratio of 50kHz/100kHz phase was found to be able to help reduce the correlation with SFL thickness for all the three configurations. The findings indicate that the appropriate selection of the current electrode distance, direction and the multi-frequency phase ratio can reduce the impact of subcutaneous fat on EIM. These settings should be evaluated for future clinical studies using hand-held localized arrays to perform EIM. PMID:27227876

  18. Optical Myography: Detecting Finger Movements by Looking at the Forearm

    PubMed Central

    Nissler, Christian; Mouriki, Nikoleta; Castellini, Claudio

    2016-01-01

    One of the crucial problems found in the scientific community of assistive/rehabilitation robotics nowadays is that of automatically detecting what a disabled subject (for instance, a hand amputee) wants to do, exactly when she wants to do it, and strictly for the time she wants to do it. This problem, commonly called “intent detection,” has traditionally been tackled using surface electromyography, a technique which suffers from a number of drawbacks, including the changes in the signal induced by sweat and muscle fatigue. With the advent of realistic, physically plausible augmented- and virtual-reality environments for rehabilitation, this approach does not suffice anymore. In this paper, we explore a novel method to solve the problem, which we call Optical Myography (OMG). The idea is to visually inspect the human forearm (or stump) to reconstruct what fingers are moving and to what extent. In a psychophysical experiment involving ten intact subjects, we used visual fiducial markers (AprilTags) and a standard web camera to visualize the deformations of the surface of the forearm, which then were mapped to the intended finger motions. As ground truth, a visual stimulus was used, avoiding the need for finger sensors (force/position sensors, datagloves, etc.). Two machine-learning approaches, a linear and a non-linear one, were comparatively tested in settings of increasing realism. The results indicate an average error in the range of 0.05–0.22 (root mean square error normalized over the signal range), in line with similar results obtained with more mature techniques such as electromyography. If further successfully tested in the large, this approach could lead to vision-based intent detection of amputees, with the main application of letting such disabled persons dexterously and reliably interact in an augmented-/virtual-reality setup. PMID:27148039

  19. Optical Myography: Detecting Finger Movements by Looking at the Forearm.

    PubMed

    Nissler, Christian; Mouriki, Nikoleta; Castellini, Claudio

    2016-01-01

    One of the crucial problems found in the scientific community of assistive/rehabilitation robotics nowadays is that of automatically detecting what a disabled subject (for instance, a hand amputee) wants to do, exactly when she wants to do it, and strictly for the time she wants to do it. This problem, commonly called "intent detection," has traditionally been tackled using surface electromyography, a technique which suffers from a number of drawbacks, including the changes in the signal induced by sweat and muscle fatigue. With the advent of realistic, physically plausible augmented- and virtual-reality environments for rehabilitation, this approach does not suffice anymore. In this paper, we explore a novel method to solve the problem, which we call Optical Myography (OMG). The idea is to visually inspect the human forearm (or stump) to reconstruct what fingers are moving and to what extent. In a psychophysical experiment involving ten intact subjects, we used visual fiducial markers (AprilTags) and a standard web camera to visualize the deformations of the surface of the forearm, which then were mapped to the intended finger motions. As ground truth, a visual stimulus was used, avoiding the need for finger sensors (force/position sensors, datagloves, etc.). Two machine-learning approaches, a linear and a non-linear one, were comparatively tested in settings of increasing realism. The results indicate an average error in the range of 0.05-0.22 (root mean square error normalized over the signal range), in line with similar results obtained with more mature techniques such as electromyography. If further successfully tested in the large, this approach could lead to vision-based intent detection of amputees, with the main application of letting such disabled persons dexterously and reliably interact in an augmented-/virtual-reality setup.

  20. Force Myography to Control Robotic Upper Extremity Prostheses: A Feasibility Study

    PubMed Central

    Cho, Erina; Chen, Richard; Merhi, Lukas-Karim; Xiao, Zhen; Pousett, Brittany; Menon, Carlo

    2016-01-01

    Advancement in assistive technology has led to the commercial availability of multi-dexterous robotic prostheses for the upper extremity. The relatively low performance of the currently used techniques to detect the intention of the user to control such advanced robotic prostheses, however, limits their use. This article explores the use of force myography (FMG) as a potential alternative to the well-established surface electromyography. Specifically, the use of FMG to control different grips of a commercially available robotic hand, Bebionic3, is investigated. Four male transradially amputated subjects participated in the study, and a protocol was developed to assess the prediction accuracy of 11 grips. Different combinations of grips were examined, ranging from 6 up to 11 grips. The results indicate that it is possible to classify six primary grips important in activities of daily living using FMG with an accuracy of above 70% in the residual limb. Additional strategies to increase classification accuracy, such as using the available modes on the Bebionic3, allowed results to improve up to 88.83 and 89.00% for opposed thumb and non-opposed thumb modes, respectively. PMID:27014682

  1. Microneedle Electrode Array for Electrical Impedance Myography to Characterize Neurogenic Myopathy.

    PubMed

    Li, Zhao; Li, Yi; Liu, Mingsheng; Cui, Liying; Yu, Yude

    2016-05-01

    Electrical impedance myography (EIM) is a noninvasive technique for neuromuscular assessment, wherein a low-intensity alternating current is applied to a muscle, and the consequent surface voltage patterns are evaluated. Commercial wet electrodes are most commonly used for EIM. However, these electrodes are not suitable for use on small muscles, as they do not effectively solve the problem of high electrode-skin contact impedance (ESCI) that negatively influences the quality of recorded biopotentials. To address this problem, we fabricated a novel microneedle electrode array (MEA) that consists of 124-µm-long microneedles. Compared to wet electrodes, the MEA could pierce through the outer skin surface in a painless and micro-invasive manner, and could thus effectively reduce ESCI. The MEA has excellent test-retest reproducibility, with intraclass correlation coefficients exceeding 0.920. When used in combination with EIM, the MEA differentiated the affected muscles from the unaffected muscles in patients with neurogenic myopathy, by using EIM parameters of reactance and phase (p = 0.023 and 0.008, respectively). Thus, the novel MEA is a practical and reusable device for EIM assessment in cases of neurogenic myopathy. However, further refinement of the electrode is needed to enhance the clinical application of the system.

  2. Force Myography to Control Robotic Upper Extremity Prostheses: A Feasibility Study.

    PubMed

    Cho, Erina; Chen, Richard; Merhi, Lukas-Karim; Xiao, Zhen; Pousett, Brittany; Menon, Carlo

    2016-01-01

    Advancement in assistive technology has led to the commercial availability of multi-dexterous robotic prostheses for the upper extremity. The relatively low performance of the currently used techniques to detect the intention of the user to control such advanced robotic prostheses, however, limits their use. This article explores the use of force myography (FMG) as a potential alternative to the well-established surface electromyography. Specifically, the use of FMG to control different grips of a commercially available robotic hand, Bebionic3, is investigated. Four male transradially amputated subjects participated in the study, and a protocol was developed to assess the prediction accuracy of 11 grips. Different combinations of grips were examined, ranging from 6 up to 11 grips. The results indicate that it is possible to classify six primary grips important in activities of daily living using FMG with an accuracy of above 70% in the residual limb. Additional strategies to increase classification accuracy, such as using the available modes on the Bebionic3, allowed results to improve up to 88.83 and 89.00% for opposed thumb and non-opposed thumb modes, respectively.

  3. Current status of federal involvement in US aquaculture. Background paper

    SciTech Connect

    1995-09-01

    The United States lacks a strong national aquaculture policy and supporting federal presence. Over the years, levels and focii of agency involvement in aquaculture development have shifted in response to legislation and its differing interpretations. The National Aquaculture Act (NAA), the primary piece of aquaculture-related legislation, is slated for reauthorization of the NAA and related legislation is the federal role in research and regulation of this emerging industry. Congress requested this Background Paper to provide information on technology issues of immediate importance to the U.S. aquaculture industry. This is a companion piece to the Background Paper on Selected Technology Issues in U.S. Aquaculture.

  4. The ELP through Time: Background Motivation, Growing Experience, Current Beliefs

    ERIC Educational Resources Information Center

    Argondizzo, Carmen; Sasso, Maria I.

    2016-01-01

    This article offers an overview of research strategies currently in use at the Language Centre of the University of Calabria and aimed at observing university students' learning habits when they are asked to use the European Language Portfolio during language courses. We present evidence of how experimental groups of students belonging to…

  5. Current Economic Issues in Employee Benefits. Background Paper No. 39.

    ERIC Educational Resources Information Center

    Woodbury, Stephen A.

    A multitude of public policy issues currently surround the tax treatment of employee benefits, particularly since the tax-favored status of employer contributions to pensions and health insurance has been blamed for a shrinking tax base that has exacerbated the federal budget deficit, an inefficient and bloated health-care sector, overinsurance by…

  6. The ELP through Time: Background Motivation, Growing Experience, Current Beliefs

    ERIC Educational Resources Information Center

    Argondizzo, Carmen; Sasso, Maria I.

    2016-01-01

    This article offers an overview of research strategies currently in use at the Language Centre of the University of Calabria and aimed at observing university students' learning habits when they are asked to use the European Language Portfolio during language courses. We present evidence of how experimental groups of students belonging to…

  7. Current Status and Perspectives of Cosmic Microwave Background Observations

    NASA Astrophysics Data System (ADS)

    Bersanelli, Marco; Maino, Davide; Mennella, Aniello

    2004-04-01

    Measurements of the cosmic microwave background (CMB) radiation provide a unique opportunity for a direct study of the primordial cosmic plasma at redshift z ~103. The angular power spectra of temperature and polarisation fluctuations are powerful observational objectives as they encode information on fundamental cosmological parameters and on the physics of the early universe. A large number of increasingly ambitious balloon-borne and ground-based experiments have been carried out following the first detection of CMB anisotropies by COBE-DMR, probing the angular power spectrum up to high multipoles. The recent data from WMAP provide a new major step forward in measurements percision. The ESA mission ``Planck Surveyor'', to be launched in 2007, is the third-generation satellite devoted to CMB imaging. Planck is expected to extract the full cosmological information from temperature anisotropies and to open up new fronteers in the CMB field.

  8. External nasal dilators: definition, background, and current uses

    PubMed Central

    Dinardi, Ricardo Reis; de Andrade, Cláudia Ribeiro; Ibiapina, Cássio da Cunha

    2014-01-01

    Our goal was to revise the literature about external nasal dilators (ENDs) as to their definition, history, and current uses. We reviewed journals in the PubMed and MEDLINE databases. The current uses hereby presented and discussed are physical exercise, nasal congestion and sleep, snoring, pregnancy, cancer, and healthy individuals. Numerous studies have shown that ENDs increase the cross-sectional area of the nasal valve, reducing nasal resistance and transnasal inspiratory pressure and stabilizing the lateral nasal vestibule, avoiding its collapse during final inspiration. These effects also facilitate breathing and are beneficial to patients with nasal obstruction. Furthermore, END use is simple, noninvasive, painless, affordable, and bears minimum risk to the user. Most studies have limited sample size and are mainly focused on physical exercise. In conclusion, ENDs seem useful, so further studies involving potential effects on the performance of physical tests and improvements in sleep quality are necessary, especially in children and teenagers. PMID:25419156

  9. Comprehensive Nuclear-Test-Ban Treaty: Background and Current Developments

    DTIC Science & Technology

    2010-12-07

    Current Developments 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT...test of an element of an aging, unmodernized stockpile in order to assure the reliability of the nuclear deterrent force. Absent such a test, the...the Administration’s effort to gain Senate support for the treaty.”17 Under Secretary of State Ellen Tauscher described elements of the

  10. The Democratic Republic of Congo: Background and Current Developments

    DTIC Science & Technology

    2010-07-23

    began in the city of Goma in the mid-1990s. The second rebellion in the late 1990s began also in eastern Congo. The root causes of the current crisis...Democratic Rally (RCD- Goma ), the Movement for the Congolese Liberation (MLC), and representatives of the unarmed political groups. The agreement called for a...dozen rebel groups and the DRC government signed the Goma Accord, primarily focused on ending the violence in Eastern Congo. Since the signing of the

  11. The Democratic Republic of Congo: Background and Current Developments

    DTIC Science & Technology

    2010-10-08

    Seko began in the city of Goma in the mid-1990s. The second rebellion in the late 1990s began also in eastern Congo. The root causes of the current...government. The All-Inclusive Agreement was signed in Pretoria, South Africa, by the DRC government, Congolese Democratic Rally (RCD- Goma ), the Movement...the Goma Accord, primarily focused on ending the violence in Eastern Congo. Since the signing of the agreement, while progress has been made, there

  12. Comprehensive Nuclear-Test-Ban Treaty: Background and Current Developments

    DTIC Science & Technology

    2009-11-23

    Current Developments 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT...tie the hands of a future administration that may have to conduct a test of an element of an aging, unmodernized stockpile in order to assure the...the treaty.”15 Under Secretary of State Ellen Tauscher described elements of the Administration’s strategy to win Senate approval of the treaty

  13. Comprehensive Nuclear-Test-Ban Treaty: Background and Current Developments

    DTIC Science & Technology

    2009-01-28

    Current Developments 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT...conduct a test of an element of an aging, unmodernized stockpile in order to assure the reliability of the nuclear deterrent force. Absent such a test...Tass, Russian Foreign Minister Sergei Lavrov “confirmed Russia’s unchanging support for the treaty as one of the key elements of the nuclear non

  14. The Democratic Republic of Congo: Background and Current Developments

    DTIC Science & Technology

    2009-07-16

    began in the city of Goma in the mid-1990s. The second rebellion in the late 1990s began also in eastern Congo. The root causes of the current crisis...committing serious atrocities against civilians in Luofu, a town north of Goma . According to the June 2009 U.N. Secretary General report “the overall...Mission in Congo (MONUC) also withdrew from some areas and pulled most of its forces into Goma . In late October, General Nkunda declared a unilateral

  15. The Democratic Republic of Congo: Background and Current Developments

    DTIC Science & Technology

    2009-03-23

    began in the city of Goma in the mid-1990s. The second rebellion in the late 1990s began also in eastern Congo. The root causes of the current crisis...withdrew from some areas and pulled most of its forces into Goma . In late October, General Nkunda declared a unilateral cease-fire and ordered his...forces to remain outside Goma . The cease-fire has been violated in recent weeks by both sides, although fighting has not spread to other parts of Congo

  16. The Democratic Republic of Congo: Background and Current Developments

    DTIC Science & Technology

    2010-06-04

    Sese Seko began in the city of Goma in the mid-1990s. The second rebellion in the late 1990s began also in eastern Congo. The root causes of the current...carry out its mandate. In August 2009, Secretary of State Hillary Clinton visited Kinshasa and Goma in eastern Congo. At a press conference with...serious atrocities against civilians in Luofu, a town north of Goma . According to the June 2009 U.N. Secretary General report, “the overall situation in

  17. Non-invasive evaluation of muscle disease in the canine model of Duchenne muscular dystrophy by electrical impedance myography

    PubMed Central

    Hakim, Chady H.; Mijailovic, Alex; Lessa, Thais B.; Coates, Joan R.; Shin, Carmen; Rutkove, Seward B.; Duan, Dongsheng

    2017-01-01

    Dystrophin-deficient dogs are by far the best available large animal models for Duchenne muscular dystrophy (DMD), the most common lethal childhood muscle degenerative disease. The use of the canine DMD model in basic disease mechanism research and translational studies will be greatly enhanced with the development of reliable outcome measures. Electrical impedance myography (EIM) is a non-invasive painless procedure that provides quantitative data relating to muscle composition and histology. EIM has been extensively used in neuromuscular disease research in both human patients and rodent models. Recent studies suggest that EIM may represent a highly reliable and convenient outcome measure in DMD patients and the mdx mouse model of DMD. To determine whether EIM can be used as a biomarker of disease severity in the canine model, we performed the assay in fourteen young (~6.6-m-old; 6 normal and 8 affected) and ten mature (~16.9-m-old; 4 normal and 6 affected) dogs of mixed background breeds. EIM was well tolerated with good inter-rater reliability. Affected dogs showed higher resistance, lower reactance and phase. The difference became more straightforward in mature dogs. Importantly, we observed a statistically significant correlation between the EIM data and muscle fibrosis. Our results suggest that EIM is a valuable objective measurement in the canine DMD model. PMID:28339469

  18. Non-invasive evaluation of muscle disease in the canine model of Duchenne muscular dystrophy by electrical impedance myography.

    PubMed

    Hakim, Chady H; Mijailovic, Alex; Lessa, Thais B; Coates, Joan R; Shin, Carmen; Rutkove, Seward B; Duan, Dongsheng

    2017-01-01

    Dystrophin-deficient dogs are by far the best available large animal models for Duchenne muscular dystrophy (DMD), the most common lethal childhood muscle degenerative disease. The use of the canine DMD model in basic disease mechanism research and translational studies will be greatly enhanced with the development of reliable outcome measures. Electrical impedance myography (EIM) is a non-invasive painless procedure that provides quantitative data relating to muscle composition and histology. EIM has been extensively used in neuromuscular disease research in both human patients and rodent models. Recent studies suggest that EIM may represent a highly reliable and convenient outcome measure in DMD patients and the mdx mouse model of DMD. To determine whether EIM can be used as a biomarker of disease severity in the canine model, we performed the assay in fourteen young (~6.6-m-old; 6 normal and 8 affected) and ten mature (~16.9-m-old; 4 normal and 6 affected) dogs of mixed background breeds. EIM was well tolerated with good inter-rater reliability. Affected dogs showed higher resistance, lower reactance and phase. The difference became more straightforward in mature dogs. Importantly, we observed a statistically significant correlation between the EIM data and muscle fibrosis. Our results suggest that EIM is a valuable objective measurement in the canine DMD model.

  19. The Global Fund to Fight AIDS, Tuberculosis, and Malaria: Background and Current Issues

    DTIC Science & Technology

    2005-03-24

    Fight AIDS, Tuberculosis , and Malaria: Background and Current Issues Updated March 24, 2005 Raymond W. Copson and Tiaji Salaam Foreign Affairs...number. 1. REPORT DATE 24 MAR 2005 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE The Global Fund to Fight AIDS, Tuberculosis , and...Prescribed by ANSI Std Z39-18 The Global Fund to Fight AIDS, Tuberculosis , and Malaria: Background and Current Issues Summary The Global Fund to Fight

  20. Dynamic responses of a riser under combined excitation of internal waves and background currents

    NASA Astrophysics Data System (ADS)

    Lou, Min; Yu, Chenglong

    2014-09-01

    In this study, the dynamic responses of a riser under the combined excitation of internal waves and background currents are studied. A modified Taylor-Goldstein equation is used to calculate the internal waves vertical structures when background currents exist. By imposing rigid-lid boundary condition, the equation is solved by Thompson-Haskell method. Based on the principle of virtual work, a nonlinear differential equation for riser motions is established combined with the modified Morison formula. Using Newmark-β method, the motion equation is solved in time domain. It is observed that the internal waves without currents exhibit dominated effect on dynamic response of a riser in the first two modes. With the effects of the background currents, the motion displacements of the riser will increase significantly in both cases that wave goes along and against the currents. This phenomenon is most obviously observed at the motions in the first mode

  1. Pressure Myography to Study the Function and Structure of Isolated Small Arteries.

    PubMed

    Schjørring, Olav L; Carlsson, Rune; Simonsen, Ulf

    2015-01-01

    Small arteries play an important role in regulation of peripheral resistance and organ perfusion. Here we describe a series of methods allowing measurements in pressurized segments of small arteries from the systemic and coronary circulation of mice as well as other species. The pressure myography techniques described include measurements of wall structure, wall stress, strain, and myogenic tone. The pressurized perfused small arteries also allow evaluation of responses to increases in pressure, flow, and drugs, where the main readout is changes in vascular diameter.

  2. Counting Grasping Action Using Force Myography: An Exploratory Study With Healthy Individuals

    PubMed Central

    Xiao, Zhen Gang

    2017-01-01

    Background Functional arm movements generally require grasping an object. The possibility of detecting and counting the action of grasping is believed to be of importance for individual with motor function deficits of the arm, as it could be an indication of the number of the functional arm movements performed by the individuals during rehabilitation. In this exploratory work, the feasibility of using armbands recording radial displacements of forearm muscles and tendons (ie, force myography, FMG) to estimate hand grasping with healthy individuals was investigated. In contrast to previous studies, this exploratory study investigates the feasibility of (1) detecting grasping when the participants move their arms, which could introduce large artifacts to the point of potentially preventing the practical use of the proposed technology, and (2) counting grasping during arm-reaching tasks. Objective The aim of this study was to determine the usefulness of FMG in the detection of functional arm movements. The use of FMG straps placed on the forearm is proposed for counting the number of grasping actions in the presence of arm movements. Methods Ten healthy volunteers participated in this study to perform a pick-and-place exercise after providing informed consent. FMG signals were simultaneously collected using 2 FMG straps worn on their wrist and at the midposition of their forearm, respectively. Raw FMG signals and 3 additional FMG features (ie, root mean square, wavelength, and window symmetry) were extracted and fed into a linear discriminant analysis classifier to predict grasping states. The transition from nongrasping to grasping states was detected during the process of counting the number of grasping actions. Results The median accuracy for detecting grasping events using FMG recorded from the wrist was 95%, and the corresponding interquartile range (IQR) was 5%. For forearm FMG classification, the median accuracy was 92%, and the corresponding IQR was 3%. The

  3. Effects of solution mass transport on the ECC ozonesonde background current. [Electrochemical Concentration Cell

    NASA Technical Reports Server (NTRS)

    Thornton, D. C.; Niazy, N.

    1983-01-01

    A technique is developed to measure the effective mass transport parameter for the electrochemical concentration cell (ECC) ozonesonde in order to determine the mass transport rate constant for the ECC as a function of pressure. It is shown that a pressure dependent factor in the background current originates in a convective mass transport parameter. It is determined that for atmospheric pressures greater than 100 mb the mass transport parameter is a constant, while at pressures less than 100 mb it decreases logarithmically with pressure. It is suggested that the background current correction is directly correlated to the mass transport parameter pressure dependence. The presently used background current correction, which is based on the partial pressure of oxygen, is found to lead to an overestimation of the integrated ozone value in the troposphere for the ECC ozonesonde data.

  4. Radioactive Background Measurements in the Neutral Current Detector Array at SNO

    NASA Astrophysics Data System (ADS)

    Cox, G. A.; Doe, P. J.; Formaggio, J. A.; McGee, S.; Stonehill, L. C.; Robertson, R. G. H.; Wall, B. L.; Wilkerson, J. F. W.; Hallin, A. L.; Poon, A. W. P.; Wouters, J. M.

    2003-10-01

    The third phase of data taking at the Sudbury Neutrino Observatory (SNO) is currently scheduled to begin in the autumn of 2003 with the installation of the Neutral Current Detectors (NCD). The NCDs, an array of ^3He proportional counters constructed from ultra-pure nickel, will measure the flux of ^8B solar neutrinos at SNO. The major sources of internal backgrounds in the NCD counters arise from U and Th chain decays. Analysis techniques have been developed to determine the level of these contaminations. These techniques and the impact of the U and Th levels on the neutral current flux measurement will be discussed.

  5. Electrical impedance myography in the evaluation of the tongue musculature in amyotrophic lateral sclerosis.

    PubMed

    Shellikeri, Sanjana; Yunusova, Yana; Green, Jordan R; Pattee, Gary L; Berry, James D; Rutkove, Seward B; Zinman, Lorne

    2015-10-01

    Electrical impedance myography (EIM) quantifies muscle health and is used as a biomarker of muscle abnormalities in neurogenic and myopathic diseases. EIM has yet to be evaluated in the tongue musculature in patients with amyotrophic lateral sclerosis (ALS), who often show clinical bulbar signs. The lingual musculature of 19 subjects with motor neuron disease and 21 normal participants was assessed using EIM, strength and endurance testing, and clinical assessment. Tongue musculature in the ALS group was characterized by significantly smaller phase (Ph) and greater resistance (R) when compared with the healthy cohort. Ph and tongue endurance were correlated in the ALS group. EIM of tongue musculature could distinguish those with ALS from healthy controls. The demonstrated relationship between tongue function and Ph supports further testing of EIM of the tongue as a potential biomarker in ALS. © 2015 Wiley Periodicals, Inc.

  6. Assessment of Optimized Electrode Configuration for Electrical Impedance Myography Using Genetic Algorithm via Finite Element Model

    PubMed Central

    Baidya, Somen

    2016-01-01

    Electrical Impedance Myography (EIM) is a noninvasive neurophysiologic technique to diagnose muscle health. Besides muscle properties, the EIM measurements vary significantly with the change of some other anatomic and nonanatomic factors such as skin fat thickness, shape and thickness of muscle, and electrode size and spacing due to its noninvasive nature of measurement. In this study, genetic algorithm was applied along with finite element model of EIM as an optimization tool in order to figure out an optimized EIM electrode setup, which is less affected by these factors, specifically muscle thickness variation, but does not compromise EIM's ability to detect muscle diseases. The results obtained suggest that a particular arrangement of electrodes and minimization of electrode surface area to its practical limit can overcome the effect of undesired factors on EIM parameters to a larger extent. PMID:27843937

  7. Electrical Impedance Myography (EIM) in the Evaluation of the Tongue Musculature in Amyotrophic Lateral Sclerosis (ALS)

    PubMed Central

    Shellikeri, Sanjana; Yunusova, Yana; Green, Jordan R.; Pattee, Gary L.; Berry, James D.; Rutkove, Seward B.; Zinman, Lorne

    2015-01-01

    Introduction Electrical impedance myography (EIM) quantifies muscle health and is used as a biomarker of muscle abnormalities in neurogenic and myopathic diseases. EIM has yet to be evaluated in the tongue musculature in people with amyotrophic lateral sclerosis (ALS), who often show clinical bulbar signs. Methods The lingual musculature of 19 subjects with motor neuron disease and 21 of normal participants were assessed using EIM, strength and endurance testing, and clinical observation. Results Tongue musculature in the ALS group was characterized by significantly smaller phase (Ph) and larger resistance (R) when compared to the healthy cohort. Ph and tongue endurance were correlated in the ALS group. Discussion EIM of tongue musculature could distinguish people with ALS from healthy controls. The demonstrated relationship between tongue function and Ph supports further testing of EIM of the tongue as a potential biomarker in ALS. PMID:25580728

  8. Deployment and background characterization of the Sudbury Neutrino Observatory Neutral Current Detectors

    NASA Astrophysics Data System (ADS)

    Stonehill, Laura C.

    The Sudbury Neutrino Observatory (SNO) is a heavy water Cherenkov detector designed to observe 8B neutrinos from the sun via elastic-scattering interactions with electrons and charged-current and neutral-current interactions with deuterium. SNO is currently taking data in its third phase, in which the detector's capabilities have been enhanced by the addition of the Neutral Current Detectors (NCDs), an array of 3He proportional counters that detect neutrons liberated in neutral-current interactions. The NCDs were designed and constructed to minimize radioactive impurities that can produce backgrounds. A variety of innovative materials and methods were used in the construction and deployment of the NCD array in order to meet the stringent purity requirements. It is important to quantify alpha backgrounds in the NCDs and to verify that the impurity levels are within design specifications. Analysis techniques relying on pulse shape characteristics, time coincidences, and energy spectra were used to identify and measure bulk 238U and 232 Th chain decays and surface 210Po decays in the nickel NCD bodies. The measured bulk impurities in the NCD array are equivalent to 5.7+1.0-0.9 picograms 232Th per gram of nickel and 2.8+0.6-0.8 picograms 238U per gram of nickel. In addition to the 43+6-7 alphas per day in the NCD array from these sources, 210Po surface contamination produces 127 +/- 2 alphas per day, and another 81+5-2 alphas per day are produced by activity in the upper portions of the disequilibrium 238U and 232Th chains. The alpha background studies presented here indicate that the alpha rates in the NCD array are in line with expectations, and will not pose a significant problem to the successful extraction of the neutral-current signal from the NCDs using pulse shape analysis techniques.

  9. ULF electromagnetic noise due to random variations of background atmospheric current and conductivity

    NASA Astrophysics Data System (ADS)

    Surkov, V. V.; Hayakawa, M.

    2007-06-01

    A mechanism of ULF electromagnetic noise generation due to random fluctuations of the atmospheric conductivity and background currents was examined. Current fluctuations similar to 1/f noise, or flicker noise, are assumed to develop inside large-scale atmospheric inhomogeneities such as thunderstorms, hurricanes, mesoscale convective systems, etc. The random current fields are assumed to be steady, uniform, and isotropic inside the inhomogeneity, which, in turn, implies that the spectral density of the process is delta correlated. A correlation radius of the random process is supposed to be dependent on gas transfer and on the acoustic wave propagation due to pressure and temperature gradients in the atmosphere. To relate the electromagnetic spectra with current fields, a transfer matrix was found, and then the correlation matrix and power spectra of the random electromagnetic field were calculated. It was shown that the large-scale random fluctuations of the atmospheric background current are capable of sustaining generation of the ULF magnetic noise that can be detected on the ground. The spectral index of magnetic noise was found to be 1.5, which is consistent with observation in the 10-2 to 10-4 Hz frequency range.

  10. An outwardly rectifying anionic background current in atrial myocytes from the human heart.

    PubMed

    Li, H; Zhang, H; Hancox, J C; Kozlowski, R Z

    2007-08-03

    This report describes a hitherto unreported anionic background current from human atrial cardiomyocytes. Under whole-cell patch-clamp with anion-selective conditions, an outwardly rectifying anion current (I(ANION)) was observed, which was larger with iodide than nitrate, and with nitrate than chloride as charge carrier. In contrast with a previously identified background anionic current from small mammal cardiomyocytes, I(ANION) was not augmented by the pyrethroid tefluthrin (10 microM); neither was it inhibited by hyperosmolar external solution nor by DIDS (200 microM); thus I(ANION) was not due to basal activity of volume-sensitive anion channels. I(ANION) was partially inhibited by the Cl(-) channel blockers NPPB (50 microM) and Gly H-101 (30 microM). Incorporation of I(ANION) into a human atrial action potential (AP) simulation led to depression of the AP plateau, accompanied by alterations to plateau inward calcium current, and to AP shortening at 50% but not 90% of complete repolarization, demonstrating that I(ANION) can influence the human atrial AP profile.

  11. The influence of helical background fields on current helicity and electromotive force of magnetoconvection

    NASA Astrophysics Data System (ADS)

    Rüdiger, G.; Küker, M.

    2016-07-01

    Motivated by the empirical finding that the known hemispheric rules for the current helicity at the solar surface are not strict, we demonstrate the excitation of small-scale current helicity by the influence of large-scale helical magnetic background fields on nonrotating magnetoconvection. This is shown within a quasilinear analytic theory of driven turbulence and by nonlinear simulations of magnetoconvection that the resulting small-scale current helicity has the same sign as the large-scale current helicity, while the ratio of both pseudoscalars is of the order of the magnetic Reynolds number of the convection. The same models do not provide finite values of the small-scale kinetic helicity. On the other hand, a turbulence-induced electromotive force is produced including the diamagnetic pumping term, as well as the eddy diffusivity but, however, no α effect. It has thus been argued that the relations for the simultaneous existence of small-scale current helicity and α effect do not hold for the model of nonrotating magnetoconvection under consideration. Calculations for various values of the magnetic Prandtl number demonstrate that, for the considered diffusivities, the current helicity increases for growing magnetic Reynolds number, which is not true for the velocity of the diamagnetic pumping, which is in agreement with the results of the quasilinear analytical approximation.

  12. Guidelines to electrode positioning for human and animal electrical impedance myography research

    PubMed Central

    Sanchez, Benjamin; Pacheck, Adam; Rutkove, Seward B.

    2016-01-01

    The positioning of electrodes in electrical impedance myography (EIM) is critical for accurately assessing disease progression and effectiveness of treatment. In human and animal trials for neuromuscular disorders, inconsistent electrode positioning adds errors to the muscle impedance. Despite its importance, how the reproducibility of resistance and reactance, the two parameters that define EIM, are affected by changes in electrode positioning remains unknown. In this paper, we present a novel approach founded on biophysical principles to study the reproducibility of resistance and reactance to electrode misplacements. The analytical framework presented allows the user to quantify a priori the effect on the muscle resistance and reactance using only one parameter: the uncertainty placing the electrodes. We also provide quantitative data on the precision needed to position the electrodes and the minimum muscle length needed to achieve a pre-specified EIM reproducibility. The results reported here are confirmed with finite element model simulations and measurements on five healthy subjects. Ultimately, our data can serve as normative values to enhance the reliability of EIM as a biomarker and facilitate comparability of future human and animal studies. PMID:27585740

  13. Optimizing electrical impedance myography of the tongue in amyotrophic lateral sclerosis.

    PubMed

    Mcilduff, Courtney E; Yim, Sung J; Pacheck, Adam K; Rutkove, Seward B

    2017-04-01

    Electrical impedance myography (EIM) can quantify muscle health at a range of frequencies, including that most commonly employed, 50 kHz. However, disease-related changes in EIM data suggest the distinction between normal and patient EIM values could be more apparent at frequencies of >50 kHz. We investigated at what other selected frequencies tongue EIM may differentiate healthy individuals and amyotrophic lateral sclerosis (ALS) patients, remain reliable, and correlate with a standard metric of bulbar function. Tongue EIM phase data from 30 volunteers and 11 ALS patients were analyzed at 6 discrete frequencies from 50 to 500 kHz. Of the frequencies assessed, EIM demonstrated maximal separation and reliability at 100 kHz, where phase value was also significantly correlated with the bulbar subscore on the revised version of the ALS Functional Rating Scale. One hundred kilohertz could serve as an optimal frequency at which to measure EIM phase values of the tongue in ALS. Muscle Nerve 55: 539-543, 2017. © 2016 Wiley Periodicals, Inc.

  14. Electrical impedance myography for the assessment of children with muscular dystrophy: a preliminary study

    NASA Astrophysics Data System (ADS)

    Rutkove, S. B.; Darras, B. T.

    2013-04-01

    Electrical impedance myography (EIM) provides a non-invasive approach for quantifying the severity of neuromuscular disease. Here we determine how well EIM data correlates to functional and ultrasound (US) measures of disease in children with Duchenne muscular dystrophy (DMD) and healthy subjects. Thirteen healthy boys, aged 2-12 years and 14 boys with DMD aged 4-12 years underwent both EIM and US measurements of deltoid, biceps, wrist flexors, quadriceps, tibialis anterior, and medial gastrocnemius. EIM measurements were performed with a custom-designed probe using a commercial multifrequency bioimpedance device. US luminosity data were quantified using a gray-scale analysis approach. Children also underwent the 6-minute walk test, timed tests and strength measurements. EIM and US data were combined across muscles. EIM 50 kHz phase was able to discriminate DMD children from healthy subjects with 98% accuracy. In the DMD patients, average EIM phase measurements also correlated well with standard functional measures. For example the 50 kHz phase correlated with the Northstar Ambulatory Assessment test (R = 0.83, p = 0.02). EIM 50 kHz phase and US correlated as well, with R = -0.79 (p < 0.001). These results show that EIM provides valuable objective measures Duchenne muscular dystrophy severity.

  15. Guidelines to electrode positioning for human and animal electrical impedance myography research

    NASA Astrophysics Data System (ADS)

    Sanchez, Benjamin; Pacheck, Adam; Rutkove, Seward B.

    2016-09-01

    The positioning of electrodes in electrical impedance myography (EIM) is critical for accurately assessing disease progression and effectiveness of treatment. In human and animal trials for neuromuscular disorders, inconsistent electrode positioning adds errors to the muscle impedance. Despite its importance, how the reproducibility of resistance and reactance, the two parameters that define EIM, are affected by changes in electrode positioning remains unknown. In this paper, we present a novel approach founded on biophysical principles to study the reproducibility of resistance and reactance to electrode misplacements. The analytical framework presented allows the user to quantify a priori the effect on the muscle resistance and reactance using only one parameter: the uncertainty placing the electrodes. We also provide quantitative data on the precision needed to position the electrodes and the minimum muscle length needed to achieve a pre-specified EIM reproducibility. The results reported here are confirmed with finite element model simulations and measurements on five healthy subjects. Ultimately, our data can serve as normative values to enhance the reliability of EIM as a biomarker and facilitate comparability of future human and animal studies.

  16. Exploration of Force Myography and surface Electromyography in hand gesture classification.

    PubMed

    Jiang, Xianta; Merhi, Lukas-Karim; Xiao, Zhen Gang; Menon, Carlo

    2017-03-01

    Whereas pressure sensors increasingly have received attention as a non-invasive interface for hand gesture recognition, their performance has not been comprehensively evaluated. This work examined the performance of hand gesture classification using Force Myography (FMG) and surface Electromyography (sEMG) technologies by performing 3 sets of 48 hand gestures using a prototyped FMG band and an array of commercial sEMG sensors worn both on the wrist and forearm simultaneously. The results show that the FMG band achieved classification accuracies as good as the high quality, commercially available, sEMG system on both wrist and forearm positions; specifically, by only using 8 Force Sensitive Resisters (FSRs), the FMG band achieved accuracies of 91.2% and 83.5% in classifying the 48 hand gestures in cross-validation and cross-trial evaluations, which were higher than those of sEMG (84.6% and 79.1%). By using all 16 FSRs on the band, our device achieved high accuracies of 96.7% and 89.4% in cross-validation and cross-trial evaluations. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  17. Background trends in California Current surface chlorophyll concentrations: A state-space view

    NASA Astrophysics Data System (ADS)

    Thomas, Andrew C.; Mendelssohn, Roy; Weatherbee, Ryan

    2013-10-01

    State-space models are applied to 13 years of monthly satellite-measured chlorophyll concentrations of the California Current, from British Columbia to Baja California, to isolate the slowly varying background trend from potentially nonstationary seasonal cycles, other higher-frequency cyclical variability, and an irregular plus measurement error signal. Temporal patterns in resulting background trends cluster into four dominant groups, three of which have increasing trends, the strongest of which extends over the coastal upwelling region from southern Oregon to Point Conception, California, and has a mean of 0.118 mg CHL m-3 decade-1. Overall, statistically significant increasing trends are observed over 75% of the study area, 20% of the study area had no trend, and 5% showed decreasing chlorophyll. Location-specific trend estimation shows increases are strongest (> 0.2 mg CHL m-3 decade-1) in upwelling areas along the Washington, Oregon and central California coasts, weaker in regions > 200 km offshore, and that positive trends are statistically significant over most of the California Current north of ˜27°N. Negative trends are evident south of ˜31°N off Baja California. These trends remain significant with similar spatial pattern, but lower magnitude, when the 1997-1998 El Niño period is removed from the analysis. State-space models of trends in alongshore wind stress and sea surface temperature over the same period indicate that local mechanisms linked to these chlorophyll trends are not clear. Comparisons of the chlorophyll trends to nonlocal signals, characterized by the North Pacific Gyre Oscillation and the Multivariate El Niño Index, map the spatially varying ecological footprint of these basin-scale signals.

  18. Cross-sectional evaluation of electrical impedance myography and quantitative ultrasound for the assessment of Duchenne muscular dystrophy in a clinical trial setting.

    PubMed

    Rutkove, Seward B; Geisbush, Tom R; Mijailovic, Aleksandar; Shklyar, Irina; Pasternak, Amy; Visyak, Nicole; Wu, Jim S; Zaidman, Craig; Darras, Basil T

    2014-07-01

    Electrical impedance myography and quantitative ultrasound are two noninvasive, painless, and effort-independent approaches for assessing neuromuscular disease. Both techniques have potential to serve as useful biomarkers in clinical trials in Duchenne muscular dystrophy. However, their comparative sensitivity to disease status and how they relate to one another are unknown. We performed a cross-sectional analysis of electrical impedance myography and quantitative ultrasound in 24 healthy boys and 24 with Duchenne muscular dystrophy, aged 2 to 14 years with trained research assistants performing all measurements. Three upper and three lower extremity muscles were studied unilaterally in each child, and the data averaged for each individual. Both electrical impedance myography and quantitative ultrasound differentiated healthy boys from those with Duchenne muscular dystrophy (P < 0.001 for both). Quantitative ultrasound values correlated with age in Duchenne muscular dystrophy boys (rho = 0.45; P = 0.029), whereas electrical impedance myography did not (rho = -0.31; P = 0.14). However, electrical impedance myography phase correlated with age in healthy boys (rho = 0.51; P = 0.012), whereas quantitative ultrasound did not (rho = -0.021; P = 0.92). In Duchenne muscular dystrophy boys, electrical impedance myography phase correlated with the North Star Ambulatory Assessment (rho = 0.65; P = 0.022); quantitative ultrasound revealed a near-significant association (rho = -0.56; P = 0.060). The two technologies trended toward a moderate correlation with one another in the Duchenne muscular dystrophy cohort but not in the healthy group (rho = -0.40; P = 0.054 and rho = -0.32; P = 0.13, respectively). Electrical impedance myography and quantitative ultrasound are complementary modalities for the assessment of boys with Duchenne muscular dystrophy; further study and application of these two modalities alone or in combination in a longitudinal fashion are warranted. Copyright

  19. Control of Phasic Firing by a Background Leak Current in Avian Forebrain Auditory Neurons

    PubMed Central

    Dagostin, André A.; Lovell, Peter V.; Hilscher, Markus M.; Mello, Claudio V.; Leão, Ricardo M.

    2015-01-01

    Central neurons express a variety of neuronal types and ion channels that promote firing heterogeneity among their distinct neuronal populations. Action potential (AP) phasic firing, produced by low-threshold voltage-activated potassium currents (VAKCs), is commonly observed in mammalian brainstem neurons involved in the processing of temporal properties of the acoustic information. The avian caudomedial nidopallium (NCM) is an auditory area analogous to portions of the mammalian auditory cortex that is involved in the perceptual discrimination and memorization of birdsong and shows complex responses to auditory stimuli We performed in vitro whole-cell patch-clamp recordings in brain slices from adult zebra finches (Taeniopygia guttata) and observed that half of NCM neurons fire APs phasically in response to membrane depolarizations, while the rest fire transiently or tonically. Phasic neurons fired APs faster and with more temporal precision than tonic and transient neurons. These neurons had similar membrane resting potentials, but phasic neurons had lower membrane input resistance and time constant. Surprisingly phasic neurons did not express low-threshold VAKCs, which curtailed firing in phasic mammalian brainstem neurons, having similar VAKCs to other NCM neurons. The phasic firing was determined not by VAKCs, but by the potassium background leak conductances, which was more prominently expressed in phasic neurons, a result corroborated by pharmacological, dynamic-clamp, and modeling experiments. These results reveal a new role for leak currents in generating firing diversity in central neurons. PMID:26696830

  20. Electrical impedance myography to assess outcome in amyotrophic lateral sclerosis clinical trials

    PubMed Central

    Rutkove, Seward B.; Zhang, Hui; Schoenfeld, David A.; Raynor, Elizabeth M.; Shefner, Jeremy M.; Cudkowicz, Merit E.; Chin, Anne B.; Aaron, Ronald; Shiffman, Carl A.

    2007-01-01

    Objective Standard outcome measures used for amyotrophic lateral sclerosis (ALS) clinical trials, including the ALS Functional Rating Scale-revised (ALSFRS-R), maximal voluntary isometric contraction testing (MVICT), and manual muscle testing (MMT) are limited in their ability to detect subtle disease progression. Electrical impedance myography (EIM) is a new non-invasive technique that provides quantitative data on muscle health by measuring localized tissue impedance. This study investigates whether EIM could provide a new outcome measure for use in ALS clinical trials work. Methods Fifteen ALS patients underwent repeated EIM measurements of one or more muscles over a period of up to 18 months and the primary outcome variable, θz-max, measured. The θz-max megascore was then calculated using the same approach as has been applied in the past for MVICT. This and the MMT data were then used to assess each measure’s statistical power to detect a given effect on disease progression in a hypothetical planned clinical therapeutic trial. Results θz-max showed a mean decline of about 21% for the test period, averaged across all patients and all tested muscles. The θz-max megascore had a power of 73% to detect a 10% treatment effect in our planned hypothetical trial, as compared to a 28% power for MMT. These results also compared favorably to historical data for ALSFRS-R and MVICT arm megascore from the trial of celecoxib in ALS, where both measures had only a 23% power to detect the same 10% treatment effect. Conclusions The θz-max megascore may provide a powerful new outcome measure for ALS clinical trials. Significance The application of EIM to future ALS trials may allow for smaller, faster studies with an improved ability to detect subtle treatment effects. PMID:17897874

  1. Feeding currents of the upside down jellyfish in the presence of background flow.

    PubMed

    Hamlet, Christina L; Miller, Laura A

    2012-11-01

    The upside-down jellyfish (Cassiopea spp.) is an ideal organism for examining feeding and exchange currents generated by bell pulsations due to its relatively sessile nature. Previous experiments and numerical simulations have shown that the oral arms play an important role in directing new fluid into the bell from along the substrate. All of this work, however, has considered the jellyfish in the absence of background flow, but the natural environments of Cassiopea and other cnidarians are dynamic. Flow velocities and directions fluctuate on multiple time scales, and mechanisms of particle capture may be fundamentally different in moving fluids. In this paper, the immersed boundary method is used to simulate a simplified jellyfish in flow. The elaborate oral arm structure is modeled as a homogenous porous layer. The results show that the oral arms trap vortices as they form during contraction and expansion of the bell. For constant flow conditions, the vortices are directed gently across the oral arms where particle capture occurs. For variable direction flows, the secondary structures change the overall pattern of the flow around the bell and appear to stabilize regions of mixing around the secondary mouths.

  2. Determination of Vascular Reactivity of Middle Cerebral Arteries from Stroke and Spinal Cord Injury Animal Models Using Pressure Myography.

    PubMed

    Anwar, Mohammad A; Eid, Ali H

    2016-01-01

    Stroke and other neurovascular derangements are main causes of global death. They, along with spinal cord injuries, are responsible for being the principal cause of disability due to neurological and cognitive problems. These problems then lead to a burden on scarce financial resources and societal care facilities as well as have a profound effect on patients' families. The mechanism of action in these debilitating diseases is complex and unclear. An important component of these problems arises from derangement of blood vessels, such as blockage due to clotting/embolism, endothelial dysfunction, and overreactivity to contractile agents, as well as alteration in endothelial permeability. Moreover, the cerebro-vasculature (large vessels and arterioles) is involved in regulating blood flow by facilitating auto-regulatory processes. Moreover, the anterior (middle cerebral artery and the surrounding region) and posterior (basilar artery and its immediate locality) regions of the brain play a significant role in triggering the pathological progression of ischemic stroke particularly due to inflammatory activity and oxidative stress. Interestingly, modifiable and non-modifiable cardiovascular risk factors are responsible for driving ischemic and hemorrhagic stroke and spinal cord injury. There are different stroke animal models to examine the pathophysiology of middle cerebral and basilar arteries. In this context, arterial myography offers an opportunity to determine the etiology of vascular dysfunction in these diseases. Herein, we describe the technique of pressure myography to examine the reactivity of cerebral vessels to contractile and vasodilator agents and a prelude to stroke and spinal cord injury.

  3. Colleges of Applied Arts and Technology of Ontario. Background Papers on Current Issues.

    ERIC Educational Resources Information Center

    Association of Colleges of Applied Arts and Technology of Ontario, Willowdale.

    Background information is provided on a number of conditions affecting Ontario's community colleges. The first section, dealing with financial issues, considers the college environment in the 1980s; examines the provincial government's perspective on priorities, the allocation process, government funding, and budgetary expenditures and trends; and…

  4. Evolution of relativistic electron current beam in a cold plasma with fixed background of ions

    NASA Astrophysics Data System (ADS)

    Rajawat, Roopendra Singh; Sengupta, Sudip; Kaw, Predhiman K.

    2016-10-01

    A numerical study of evolution of relativistic electron current beam in a cold homogeneous plasma with immobile ions has been carried out using one dimensional electrostatic relativistic particle-in-cell code. It is found that the beam current when longitudinally perturbed by imposing a relativistically intense wave, diminishes with time due to phase mixing effects, arising because of spatial variation of relativistic mass. Studies have been conducted for various flow velocities (v0 / c) and relativistic intensities (eE0/mωpe c ) of the perturbed wave. Rate of decay of current decreases with increasing flow velocity for a fixed (eE0/mωpe c ); and for a given initial current the final magnitude of current decreases with increasing relativistic intensity of the perturbed wave.

  5. Two-stream stability properties of the return-current layer for intense ion beam propagation through background plasma

    SciTech Connect

    Startsev, Edward A.; Davidson, Ronald C.; Dorf, Mikhail

    2009-09-15

    When an ion beam with sharp edge propagates through a background plasma, its current is neutralized by the plasma return current everywhere except at the beam edge over a characteristic transverse distance {delta}x{sub perpendicular}{approx}{delta}{sub pe}, where {delta}{sub pe}=c/{omega}{sub pe} is the collisionless skin depth and {omega}{sub pe} is the electron plasma frequency. Because the background plasma electrons neutralizing the ion beam current inside the beam are streaming relative to the background plasma electrons outside the beam, the background plasma can support a two-stream surface-mode excitation. Such surface modes have been studied previously assuming complete charge and current neutralization, and have been shown to be strongly unstable. In this paper we study the detailed stability properties of this two-stream surface mode for an electron flow velocity profile self-consistently driven by the ion beam. In particular, it is shown that the self-magnetic field generated inside the unneutralized current layer, which has not been taken into account previously, completely eliminates the instability.

  6. The Interaction of Short-Wavelength Internal Waves with a Background Current,

    DTIC Science & Technology

    1982-12-01

    convergence ends as the rays (in a WKB sense) become more horizontal. In Hartman’s work, the decay is monotonic because of the initial conditions. These...horizontal phase speed of the short waves and U0 is the iFaximum mean flow velocity. The solutions also reveal The inaccuracy of WKB predictions where applied...Background .............................................................................. 5 3 Scale Estimates and WKB Accuracy

  7. The Metis Betterment Act: History and Current Status. Background Paper No. 6.

    ERIC Educational Resources Information Center

    Alberta Dept. of Native Affairs, Edmonton.

    This paper reviews the history and current status of the eight Metis settlements established in the 1940s for people of mixed white and Indian blood living traditional Indian lifestyles in Alberta. The Ewing Commission first reported in 1936 on the Metis people who were not allocated reserves as status Indians and did not have squatters' rights on…

  8. Behaviour of the electrical impedance myography in isometric contraction of biceps brachii at different elbow joint angles

    NASA Astrophysics Data System (ADS)

    Coutinho, A. B. B.; Jotta, B.; Pino, A. V.; Souza, M. N.

    2012-12-01

    Electrical impedance myography (EIM) can be understood as an experimental technique applied to evaluate bioelectrical impedance associated to the muscular activity. With the development of technique, some studies are trying to associate the EIM parameters with the morphological and physiological changes that occur in the muscle during contraction. In this context this work sought to associate EIM parameters observed during isometric contractions of the biceps brachii muscle at different elbow joint angles with the correspondent muscular force. Differently from previous works that did not observe significant correlation between those data, our findings point to high correlations between the some EIM resistive parameters and the muscle force. Despite the need of further investigation, our results indicated that EIM technique can be used to estimate muscle force in a noninvasive way.

  9. Effects of background noise on the response of rat and cat motoneurones to excitatory current transients.

    PubMed Central

    Poliakov, A V; Powers, R K; Sawczuk, A; Binder, M D

    1996-01-01

    1. We studied the responses of rat hypoglossal motoneurones to excitatory current transients (ECTs) using a brainstem slice preparation. Steady, repetitive discharge at rates of 12-25 impulses s-1 was elicited from the motoneurones by injecting long (40 s) steps of constant current. Poisson trains of the ECTs were superimposed on these steps. The effects of additional synaptic noise was simulated by adding a zero-mean random process to the stimuli. 2. We measured the effects of the ECTs on motoneurone discharge probability by compiling peristimulus time histograms (PSTHs) between the times of occurrence of the ECTs and the motoneurone spikes. The ECTs produced modulation of motoneurone discharge similar to that produced by excitatory postsynaptic currents. 3. The addition of noise altered the pattern of the motoneurone response to the current transients: both the amplitude and the area of the PSTH peaks decreased as the power of the superimposed noise was increased. Noise tended to reduce the efficacy of the ECTs, particularly when the motoneurones were firing at lower frequencies. Although noise also increased the firing frequency of the motoneurones slightly, the effects of noise on ECT efficacy did not simply result from noise-induced changes in mean firing rate. 4. A modified version of the experimental protocol was performed in lumbar motoneurones of intact, pentobarbitone-anaesthetized cats. These recordings yielded results similar to those obtained in rat hypoglossal motoneurones in vitro. 5. Our results suggest that the presence of concurrent synaptic inputs reduces the efficacy of any one input. The implications of this change in efficacy and the possible underlying mechanisms are discussed. PMID:8866358

  10. Current Chinese Leadership: Background, Associations, and Issues for Selected Key Military Leaders

    DTIC Science & Technology

    1985-09-01

    However, decadent bourgeois ideas and lifestyles will seize the opportunity to corrupt our people .... therefore, it is important to eliminate... Louise O’Callaghan, "Opening Up China’s Great North- west," The Guardian (Manchester), 20 September 1984, p. 9. 151 CURRENT CHINESE LEADERSHIP...SOURCES Mary- Louise O’Callaghan, "The Dark Side of China." Christian Science Monitor (Boston), 20 November 1984, pp. 32-33. Ming Bao (Hong Kong), 10

  11. Background and Current Treatment of Squamous Cell Carcinoma of the Anus.

    PubMed

    Glynne-Jones, Rob; Saleem, Waqar; Harrison, Mark; Mawdsley, Suzy; Hall, Marcia

    2016-01-01

    In this review, a summary of our current understanding of squamous cell carcinoma of the anus (SCCA) and the advances in our knowledge of SCCA regarding screening, prevention, the role of the immune system, current treatment and the potential for novel targets are discussed. The present standard of care in terms of treatment is 5-fluorouracil (5-FU) and mitomycin C (MMC) concurrently with radiation, which results in a high level of disease control for small early cancers. Preservation of the anal sphincter is achieved in the majority, although anorectal function is often impaired. Although evidence from prospective studies to support a change in the treatment strategy is lacking, patients with HPV-negative SCCA appear to be less responsive to chemoradiation (CRT) and relapse more frequently. In contrast, HPV-positive tumours usually fare better, but oncological outcomes are modified by smoking and immune incompetence. There is current interest in escalating the radiotherapy dose for larger, more advanced tumours, and de-escalating treatment for HPV-positive tumours. The use of novel immunological treatments to target the underlying different molecular pathways of HPV-positive cancers is exciting.

  12. τ-→η(')π-ντγ decays as background in the search for second class currents

    NASA Astrophysics Data System (ADS)

    Guevara, A.; López-Castro, G.; Roig, P.

    2017-03-01

    Observation of τ-→η(')π-ντ decays at Belle-II would indicate either a manifestation of isospin symmetry breaking or genuine second class current (SCC) effects. The corresponding radiative τ-→η(')π-ντγ decay channels are not suppressed by G -parity considerations and may represent a serious background in searches of SCCs in the former. We compute the observables associated to these radiative decays using resonance chiral Lagrangians and conclude that vetoing photons with Eγ>100 MeV should get rid of this background in the Belle-II environment while searching for the τ-→η π-ντ channel. Similar considerations hold inconclusive for decays involving the η', given the theory's uncertainties in the prediction of the τ-→η'π-ντ branching ratio. Still, additional kinematics-based cuts should be able to suppress this background in the η' case to a negligible level.

  13. Differences between previously married and never married 'gay' men: family background, childhood experiences and current attitudes.

    PubMed

    Higgins, Daryl J

    2004-01-01

    Despite a large body of literature on the development of sexual orientation, little is known about why some gay men have been (or remain) married to a woman. In the current study, a self-selected sample of 43 never married gay men ('never married') and 26 gay men who were married to a woman ('previously married') completed a self-report questionnaire. Hypotheses were based on five possible explanations for gay men's marriages: (a) differences in sexual orientation (i.e., bisexuality); (b) internalized homophobia; (c) religious intolerance; (d) confusion created because of childhood/adolescent sexual experiences; and/or (e) poor psychological adjustment. Previously married described their families' religious beliefs as more fundamentalist than never married. No differences were found between married' and never married' ratings of their sexual orientation and identity, and levels of homophobia and self-depreciation. Family adaptability and family cohesion and the degree to which respondents reported having experienced child maltreatment did not distinguish between previously married and never married. The results highlight how little is understood of the reasons why gay men marry, and the need to develop an adequate theoretical model.

  14. The EOS land validation core sites: background information and current status

    USGS Publications Warehouse

    Morisette, J.; Privette, J.L.; Justice, C.; Olson, D.; Dwyer, J.; Davis, P.; Starr, D.; Wickland, D.

    1999-01-01

    The EOS Land Validation Core Sites1 will provide the user community with timely ground, aircraft, and satellite data for EOS science and validation investigations. The sites, currently 24 distributed worldwide, represent a consensus among the instrument teams and validation investigators and represent a range of global biome types (see Figure 1 and Table 1; Privette et al., 1999; Justice et al., 1998). The sites typically have a history of in situ and remote observations and can expect continued monitoring and land cover research activities. In many cases, a Core Site will have a tower equipped with above-canopy instrumentation for nearcontinuous sampling of landscape radiometric, energy and CO2 flux, meteorological variables, and atmospheric aerosol and water vapor data. These will be complemented by intensive field measurement campaigns. The data collected at these sites will provide an important resource for the broader science community. These sites can also provide a foundation for a validation network supported and used by all international space agencies.

  15. Layer-by-layer assembled carbon nanotube films with molecule recognition function and lower capacitive background current.

    PubMed

    Kong, Bo; Zeng, Jinxiang; Luo, Guangming; Luo, Shenglian; Wei, Wanzhi; Li, Jun

    2009-02-01

    Multilayer films of multiwalled carbon nanotubes (MWCNTs) with molecule recognition function were assembled on glassy carbon (GC) electrode with lower capacitive background current by two steps: first, MWCNTs interacted with beta-cyclodextrin (beta-CD) with the aid of sonication to form beta-CD-MWCNTs nanocomposite, then the beta-CD-MWCNTs nanocomposite was assembled on GC electrode using layer-by-layer (LBL) method based on electrostatic interaction of positively charged biopolymer chitosan and negatively charged MWCNTs. The assembled beta-CD-MWCNTs multilayer films were characterized by scanning electron microscopy (SEM) and cyclic voltammetry. The SEM indicated that the MWCNTs multilayer films with beta-CD were somewhat more compact than that of the MWCNTs multilayer films without beta-CD. The cyclic voltammetric results indicated that the assembled MWCNTs with beta-CD on GC electrode exhibited lower capacitive background current than the assembled MWCNTs without beta-CD. The MWCNTs multilayer films with beta-CD were studied with respect to the electrocatalytic activity toward dopamine (DA). Compared with the MWCNTs multilayer films without beta-CD, the MWCNTs multilayer films with beta-CD possesses a much lower capacitive background current and higher electrocatalytic activity in phosphate buffer, which was ascribed to the relatively compact three-dimensional structure of the MWCNTs multilayer films with beta-CD and the excellent molecule recognition function of beta-CD.

  16. Current Background Noise Sources and Levels in the NASA Ames 40- by 80-Foot Wind Tunnel: A Status Report

    NASA Technical Reports Server (NTRS)

    Allen, Christopher S.; Jaeger, Stephen; Soderman, Paul; Koga, Dennis (Technical Monitor)

    1999-01-01

    Background noise measurements were made of the acoustic environment in the National Full-Scale Aerodynamics Complex 40- by 80-Foot Wind Tunnel (40x80) at NASA Ames Research Center. The measurements were acquired subsequent to the 40x80 Aeroacoustic Modernization Project, which was undertaken to improve the anechoic characteristics of the 40x80's closed test section as well as reduce the levels of background noise in the facility. The resulting 40x80 anechoic environment was described by Soderman et. al., and the current paper describes the resulting 40x80 background noise, discusses the sources of the noise, and draws comparisons to previous 40x80 background noise levels measurements. At low wind speeds or low frequencies, the 40x80 background noise is dominated by the fan drive system. To obtain the lowest fan drive noise for a given tunnel condition, it is possible in the 40x80 to reduce the fans' rotational speed and adjust the fans' blade pitch, as described by Schmidtz et. al. This idea is not new, but has now been operationally implemented with modifications for increased power at low rotational speeds. At low to mid-frequencies and at higher wind speeds, the dominant noise mechanism was thought to be caused by the surface interface of the previous test section floor acoustic lining. In order to reduce this noise mechanism, the new test section floor lining was designed to resist the pumping of flow in and out of the space between the grating slats required to support heavy equipment. In addition, the lining/flow interface over the entire test section was designed to be smoother and quieter than the previous design. At high wind speeds or high frequencies, the dominant source of background noise in the 40x80 is believed to be caused by the response of the in-flow microphone probes (required by the nature of the closed test section) to the fluctuations in the freestream flow. The resulting background noise levels are also different for probes of various

  17. A more precise, repeatable and diagnostic alternative to surface electromyography - an appraisal of the clinical utility of acoustic myography.

    PubMed

    Harrison, Adrian P

    2017-03-02

    Acoustic myography (AMG) enables a detailed and accurate measurement of those muscles involved in a particular movement and is independent of electrical signals between the nerve and muscle, measuring solely muscle contractions, unlike surface electromyography (sEMG). With modern amplifiers and digital sound recording systems, measurements during physical activity both inside and outside a laboratory setting are now possible and accurate. Muscle sound gives a representation of the work of each muscle group during a complex movement, and under certain forms of movement even reveals both concentric and eccentric activity, something that sEMG is incapable of. Recent findings suggest that AMG has a number of advantages over sEMG, being simple to use, accurate and repeatable as well as being intuitive to interpret. The AMG signal comprises three physiological parameters, namely efficiency/coordination (E-score), spatial summation (S-score) and temporal summation (T-score). It is concluded that modern AMG units have the potential to accurately assess patients with neuromuscular and musculoskeletal complaints in hospital clinics, home monitoring situations as well as sports settings. © 2017 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  18. Advanced Practice Registered Nurses and Physician Assistants in Sleep Centers and Clinics: A Survey of Current Roles and Educational Background

    PubMed Central

    Colvin, Loretta; Cartwright, Ann; Collop, Nancy; Freedman, Neil; McLeod, Don; Weaver, Terri E.; Rogers, Ann E.

    2014-01-01

    Study Objectives: To survey Advanced Practice Registered Nurse (APRN) and Physician Assistant (PA) utilization, roles and educational background within the field of sleep medicine. Methods: Electronic surveys distributed to American Academy of Sleep Medicine (AASM) member centers and APRNs and PAs working within sleep centers and clinics. Results: Approximately 40% of responding AASM sleep centers reported utilizing APRNs or PAs in predominantly clinical roles. Of the APRNs and PAs surveyed, 95% reported responsibilities in sleep disordered breathing and more than 50% in insomnia and movement disorders. Most APRNs and PAs were prepared at the graduate level (89%), with sleep-specific education primarily through “on the job” training (86%). All APRNs surveyed were Nurse Practitioners (NPs), with approximately double the number of NPs compared to PAs. Conclusions: APRNs and PAs were reported in sleep centers at proportions similar to national estimates of NPs and PAs in physicians' offices. They report predominantly clinical roles, involving common sleep disorders. Given current predictions that the outpatient healthcare structure will change and the number of APRNs and PAs will increase, understanding the role and utilization of these professionals is necessary to plan for the future care of patients with sleep disorders. Surveyed APRNs and PAs reported a significant deficiency in formal and standardized sleep-specific education. Efforts to provide formal and standardized educational opportunities for APRNs and PAs that focus on their clinical roles within sleep centers could help fill a current educational gap. Citation: Colvin L, Cartwright Ann, Collop N, Freedman N, McLeod D, Weaver TE, Rogers AE. Advanced practice registered nurses and physician assistants in sleep centers and clinics: a survey of current roles and educational background. J Clin Sleep Med 2014;10(5):581-587. PMID:24812545

  19. Computer-aided technology for fabricating complete dentures: systematic review of historical background, current status, and future perspectives.

    PubMed

    Bidra, Avinash S; Taylor, Thomas D; Agar, John R

    2013-06-01

    Computer-aided technology is an emerging method for fabricating complete dentures. Consolidated information about historical background, current status, and scope for the future is lacking. The purpose of this systematic review was to analyze the existing literature on computer-aided technology for fabricating complete dentures and provide the reader with a historical background, current status, and future perspectives on this emerging technology. An electronic search of the English language literature between the periods of January 1957 and June 2012 was performed by using PubMed/MEDLINE with the following specific search terms: CAD-CAM complete dentures, digital complete dentures, computer dentures, designed dentures, machined dentures, manufactured dentures, milled dentures, and rapid prototyping dentures. Additionally, the search terms were used on the Google search engine to identify current commercial manufacturers and their protocols. A total of 1584 English language titles were obtained from the electronic database, and the systematic application of exclusion criteria resulted in the identification of 8 articles pertaining to computer-aided technology for complete dentures. Since the first published report in 1994, multiple authors have described different theoretical models and protocols for fabricating complete dentures with computer-aided technology. Although no clinical trials or clinical reports were identified in the scientific literature, the Google search engine identified 2 commercial manufacturers in the United States currently fabricating complete dentures with computer-aided design and computer-aided manufacturing (CAD/CAM) technology for clinicians world-wide. These manufacturers have definitive protocols in place and offer exclusive dental materials, techniques, and laboratory support. Their protocols contrast with conventional paradigms for fabricating complete dentures and allow the fabrication of complete dentures in 2 clinical appointments

  20. Anesthetic activation of central respiratory chemoreceptor neurons involves inhibition of a THIK-1-like background K+ current

    PubMed Central

    Lazarenko, Roman M.; Fortuna, Michal G.; Shi, Yingtang; Mulkey, Daniel K.; Takakura, Ana C.; Moreira, Thiago S.; Guyenet, Patrice G.; Bayliss, Douglas A.

    2010-01-01

    At surgical depths of anesthesia, inhalational anesthetics cause a loss of motor response to painful stimuli (i.e., immobilization) that is characterized by profound inhibition of spinal motor circuits. Yet, although clearly depressed, the respiratory motor system continues to provide adequate ventilation under these same conditions. Here, we show that isoflurane causes robust activation of CO2/pH-sensitive, Phox2b-expressing neurons located in the retrotrapezoid nucleus (RTN) of the rodent brainstem, in vitro and in vivo. In brainstem slices from Phox2b-eGFP mice, the firing of pH-sensitive RTN neurons was strongly increased by isoflurane, independent of prevailing pH conditions. At least two ionic mechanisms contributed to anesthetic activation of RTN neurons: activation of a Na+-dependent cationic current and inhibition of a background K+ current. Single cell RT-PCR analysis of dissociated GFP-labeled RTN neurons revealed expression of THIK-1 (K2P13.1), a channel that shares key properties with the native RTN current (i.e., suppression by inhalational anesthetics, weak rectification, inhibition by extracellular Na+, and pH-insensitivity). Isoflurane also increased firing rate of RTN chemosensitive neurons in urethane-anesthetized rats, again independent of CO2 levels. In these animals, isoflurane transiently enhanced activity of the respiratory system, an effect that was most prominent at low levels of respiratory drive and mediated largely by an increase in respiratory frequency. These data indicate that inhalational anesthetics cause activation of RTN neurons, which serve an important integrative role in respiratory control; the increased drive provided by enhanced RTN neuronal activity may contribute, in part, to maintaining respiratory motor activity under immobilizing anesthetic conditions. PMID:20610767

  1. Electrical Impedance Myography to Detect the Effects of Electrical Muscle Stimulation in Wild Type and Mdx Mice

    PubMed Central

    Li, Jia; Yim, Sung; Pacheck, Adam; Sanchez, Benjamin; Rutkove, Seward B.

    2016-01-01

    Objective Tools to better evaluate the impact of therapy on nerve and muscle disease are needed. Electrical impedance myography (EIM) is sensitive to neuromuscular disease progression as well as to therapeutic interventions including myostatin inhibition and antisense oligonucleotide-based treatments. Whether the technique identifies the impact of electrical muscle stimulation (EMS) is unknown. Methods Ten wild-type (wt) C57B6 mice and 10 dystrophin-deficient (mdx) mice underwent 2 weeks of 20 min/day EMS on left gastrocnemius and sham stimulation on the right gastrocnemius. Multifrequency EIM data and limb girth were obtained before and at the conclusion of the protocol. Muscle weight, in situ force measurements, and muscle fiber histology were also assessed at the conclusion of the study. Results At the time of sacrifice, muscle weight was greater on the EMS-treated side than on the sham-stimulated side (p = 0.018 for wt and p = 0.007 for mdx). Similarly, in wt animals, EIM parameters changed significantly compared to baseline (resistance (p = 0.009), reactance (p = 0.0003) and phase (p = 0.002); these changes were due in part to reductions in the EIM values on the EMS-treated side and elevations on the sham-simulated side. Mdx animals showed analogous but non-significant changes (p = 0.083, p = 0.064, and p = 0.57 for resistance, reactance and phase, respectively). Maximal isometric force trended higher on the stimulated side in wt animals only (p = 0.06). Myofiber sizes in wt animals were also larger on the stimulated side than on the sham-stimulated side (p = 0.034); no significant difference was found in the mdx mice (p = 0.79). Conclusion EIM is sensitive to stimulation-induced muscle alterations in wt animals; similar trends are also present in mdx mice. The mechanisms by which these EIM changes develop, however, remains uncertain. Possible explanations include longer-term trophic effects and shorter-term osmotic effects. PMID:26986564

  2. Investigation of the Effects of Facility Background Pressure on the Performance and Voltage-Current Characteristics of the High Voltage Hall Accelerator

    NASA Technical Reports Server (NTRS)

    Kamhawi, Hani; Huang, Wensheng; Haag, Thomas; Spektor, Rostislav

    2014-01-01

    The National Aeronautics and Space Administration (NASA) Science Mission Directorate In-Space Propulsion Technology office is sponsoring NASA Glenn Research Center to develop a 4 kW-class Hall thruster propulsion system for implementation in NASA science missions. A study was conducted to assess the impact of varying the facility background pressure on the High Voltage Hall Accelerator (HiVHAc) thruster performance and voltage-current characteristics. This present study evaluated the HiVHAc thruster performance in the lowest attainable background pressure condition at NASA GRC Vacuum Facility 5 to best simulate space-like conditions. Additional tests were performed at selected thruster operating conditions to investigate and elucidate the underlying physics that change during thruster operation at elevated facility background pressure. Tests were performed at background pressure conditions that are three and ten times higher than the lowest realized background pressure. Results indicated that the thruster discharge specific impulse and efficiency increased with elevated facility background pressure. The voltage-current profiles indicated a narrower stable operating region with increased background pressure. Experimental observations of the thruster operation indicated that increasing the facility background pressure shifted the ionization and acceleration zones upstream towards the thruster's anode. Future tests of the HiVHAc thruster are planned at background pressure conditions that are expected to be two to three times lower than what was achieved during this test campaign. These tests will not only assess the impact of reduced facility background pressure on thruster performance, voltage-current characteristics, and plume properties; but will also attempt to quantify the magnitude of the ionization and acceleration zones upstream shifting as a function of increased background pressure.

  3. Investigation of the Effects of Facility Background Pressure on the Performance and Voltage-Current Characteristics of the High Voltage Hall Accelerator

    NASA Technical Reports Server (NTRS)

    Kamhawi, Hani; Huang, Wensheng; Haag, Thomas; Spektor, Rostislav

    2014-01-01

    The National Aeronautics and Space Administration (NASA) Science Mission Directorate In-Space Propulsion Technology office is sponsoring NASA Glenn Research Center to develop a 4 kW-class Hall thruster propulsion system for implementation in NASA science missions. A study was conducted to assess the impact of varying the facility background pressure on the High Voltage Hall Accelerator (HiVHAc) thruster performance and voltage-current characteristics. This present study evaluated the HiVHAc thruster performance in the lowest attainable background pressure condition at NASA GRC Vacuum Facility 5 to best simulate space-like conditions. Additional tests were performed at selected thruster operating conditions to investigate and elucidate the underlying physics that change during thruster operation at elevated facility background pressure. Tests were performed at background pressure conditions that are three and ten times higher than the lowest realized background pressure. Results indicated that the thruster discharge specific impulse and efficiency increased with elevated facility background pressure. The voltage-current profiles indicated a narrower stable operating region with increased background pressure. Experimental observations of the thruster operation indicated that increasing the facility background pressure shifted the ionization and acceleration zones upstream towards the thrusters anode. Future tests of the HiVHAc thruster are planned at background pressure conditions that are expected to be two to three times lower than what was achieved during this test campaign. These tests will not only assess the impact of reduced facility background pressure on thruster performance, voltage-current characteristics, and plume properties; but will also attempt to quantify the magnitude of the ionization.

  4. Recent Bremsstrahlung-based assays of (210)Pb in lead and comments on current availability of low-background lead in North America.

    PubMed

    Keillor, Martin E; Aalseth, C E; Arnquist, I J; Eggemeyer, T A; Fuller, E S; Glasgow, B D; Hoppe, E W; Morley, S M; Myers, A W; Orrell, J L; Overman, C T; Seifert, A; Shaff, S M; Thommasson, K S

    2017-03-03

    Low-background lead for radiation measurement shielding is often assayed for (210)Pb to ensure acceptable backgrounds. Samples of lead assayed with a germanium spectrometer calibrated for bremsstrahlung-based assay of (210)Pb provide a view into the (210)Pb content of commercial lead in the U.S. (other than stockpiled Doe Run lead). Results suggest that the loss of lead smelting in the U.S. has eliminated the traditional supply of "low background" lead (~30Bqkg(-1)), and indicate current commercial supplies contain roughly an order of magnitude higher (210)Pb levels.

  5. Charged-particle acceleration in a reconnecting current sheet including multiple magnetic islands and a nonuniform background magnetic field

    NASA Astrophysics Data System (ADS)

    Li, Y.; Wu, N.; Lin, J.

    2017-09-01

    Context. Charged particles are accelerated to high energies in solar flares. Although we know that magnetic reconnection is an efficient mechanism in generating energetic particles, the detailed role it plays in accelerating particles is still unknown. Aims: We investigate particle acceleration by magnetic reconnection in the current sheet, including multiple islands and a guide field. Methods: The long current sheet produced by the disruption in the corona magnetic field is usually not stable to various plasma instabilities, among which the tearing mode is the most important, and magnetic islands start to form in the current sheet when these instabilities develop. Two reverse processes are typically observed in the sheet: cascading of large islands to smaller ones, and merging of small islands into larger ones. Coalescent reconnection consequently takes place between two adjacent islands when merging occurs. The electric field induced by the coalescent reconnection is opposite to the electric field of the primary large-scale reconnection. We studied particle acceleration in such a current sheet and examined in detail the dynamic properties of electrons and protons in the current sheet through test particle approach. Results: We found that some particles can be accelerated to high energies in a very short time, and some particles (near the coalescence reconnection site) are accelerated and decelerated back and forth by the primary and secondary electric fields. Particle motions show two distinct types along different trajectories: some particles are trapped around magnetic islands, and some escape from the current sheet mainly along open field lines. With the presence of a guide field, protons and electrons are found to eventually move in different directions. The energy spectra for both species follow a double power-law shape. The softer components of the power-law spectrum are due to the particles that are trapped and circulate around magnetic islands, while the

  6. Charge and current neutralization of an ion-beam pulse propagating in a background plasma along a solenoidal magnetic field.

    PubMed

    Kaganovich, I D; Startsev, E A; Sefkow, A B; Davidson, R C

    2007-12-07

    The analytical studies show that the application of a small solenoidal magnetic field can drastically change the self-magnetic and self-electric fields of the beam pulse propagating in a background plasma. Theory predicts that when omega_{ce} approximately omega_{pe}beta_{b}, where omega_{ce} is the electron gyrofrequency, omega_{pe} is the electron plasma frequency, and beta_{b} is the ion-beam velocity relative to the speed of light, there is a sizable enhancement of the self-electric and self-magnetic fields due to the dynamo effect. Furthermore, the combined ion-beam-plasma system acts as a paramagnetic medium; i.e., the solenoidal magnetic field inside the beam pulse is enhanced.

  7. Relativistic electron's butterfly pitch angle distribution modulated by localized background magnetic field perturbation driven by hot ring current ions

    NASA Astrophysics Data System (ADS)

    Xiong, Ying; Chen, Lunjin; Xie, Lun; Fu, Suiyan; Xia, Zhiyang; Pu, Zuyin

    2017-05-01

    Dayside modulated relativistic electron's butterfly pitch angle distributions (PADs) from ˜200 keV to 2.6 MeV were observed by Van Allen Probe B at L = 5.3 on 15 November 2013. They were associated with localized magnetic dip driven by hot ring current ion (60-100 keV proton and 60-200 keV helium and oxygen) injections. We reproduce the electron's butterfly PADs at satellite's location using test particle simulation. The simulation results illustrate that a negative radial flux gradient contributes primarily to the formation of the modulated electron's butterfly PADs through inward transport due to the inductive electric field, while deceleration due to the inductive electric field and pitch angle change also makes in part contribution. We suggest that localized magnetic field perturbation, which is a frequent phenomenon in the magnetosphere during magnetic disturbances, is of great importance for creating electron's butterfly PADs in the Earth's radiation belts.

  8. Relativistic electron's butterfly pitch angle distribution modulated by localized background magnetic field perturbation driven by hot ring current ions

    NASA Astrophysics Data System (ADS)

    Xiong, Ying; Chen, Lunjin; Xie, Lun; Fu, Suiyan; Pu, Zuyin

    2017-04-01

    Dayside modulated relativistic electron's butterfly pitch angle distributions (PADs) from 200 keV to 2.6 MeV was observed by Van Allen Probe-B at L = 5.3 on November 15, 2013. They were associated with localized magnetic dip driven by hot ring current ion (60-100 keV protons and 60-200 keV oxygen) injections. We reproduce the electron's butterfly PADs at satellite's location using test particle simulation. The simulation results illustrate that negative radial flux gradient contributes primarily to the formation of the modulated electron's butterfly PADs through inward transport due to the inductive electric field, while deceleration due to the inductive electric field and pitch angle change make in part contribution. We suggest that localized magnetic field perturbation, which is a frequent phenomenon in the magnetosphere during magnetic disturbances, is of great importance for creating electron's butterfly PADs in the Earth's radiation belts.

  9. Electromagnetic analysis of a superconducting transformer for high current characterization of cable in conduit conductors in background magnetic field

    NASA Astrophysics Data System (ADS)

    Wu, Xiangyang; Tan, Yunfei; Fang, Zhen; Jiang, Donghui; Chen, Zhiyou; Chen, Wenge; Kuang, Guangli

    2017-10-01

    A large cable-in-conduit-conductor (CICC) test facility has been designed and fabricated at the High Magnetic Field Laboratory of the Chinese Academy of Sciences (CHMFL) in order to meet the test requirement of the conductors which are applied to the future fusion reactor. The critical component of the test facility is an 80 kA superconducting transformer which consists of a multi-turn primary coil and a minor-turn secondary coil. As the current source of the conductor samples, the electromagnetic performance of the superconducting transformer determines the stability and safety of the test facility. In this paper, the key factors and parameters, which have much impact on the performance of the transformer, are analyzed in detail. The conceptual design and optimizing principles of the transformer are discussed. An Electromagnetic-Circuit coupled model built in ANSYS Multiphysics is successfully used to investigate the electromagnetic characterization of the transformer under the dynamic operation condition.

  10. Commentary on current changes of the SoHT 2016 consensus on alcohol markers in hair and further background information.

    PubMed

    Pragst, Fritz; Suesse, Silke; Salomone, Alberto; Vincenti, Marco; Cirimele, Vincent; Hazon, Jayne; Tsanaclis, Lolita; Kingston, Robert; Sporkert, Frank; Baumgartner, Markus R

    2017-09-01

    The consensus on alcohol markers in hair was revised for the fourth time by an expert group of the Society of Hair Testing based on current state of research. This revision was adopted by the members of the Society during the business meeting in Brisbane on August 29th 2016. For both markers, ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEEs), two cut-off values for discrimination between teetotalers or occasional low amount consumption and moderate alcohol drinking (low cut-off), and between non-excessive (abstinence up to moderate alcohol intake) and chronic excessive drinking (high cut-off value) were critically examined. For the current revision, the cut-off values for EtG (7pg/mg and 30pg/mg, respectively) remained unchanged despite different findings or discussions published in the meantime. This was mainly due to the lack of broader data collections from new studies with great numbers of volunteers following thorough study concepts. In contrast, an essential change of the consensus was accepted for the FAEEs, where the concentration of ethyl palmitate (E16:0) can be used autonomously for interpretation instead of the concentration sum (ΣFAEE) of the four esters ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate, as previously applied. After evaluation of the data from seven laboratories, the E16:0 cut-off for abstinence assessment was defined at 0.12ng/mg for the 0-3cm segment and at 0.15ng/mg for the 0-6cm segment. The cut-off for chronic excessive drinking was fixed at 0.35ng/mg for the 0-3cm segment and at 0.45ng/mg for the 0-6cm segment. The use of E16:0 with these cut-offs in place of ΣFAEE for alcohol intake assessment produces only a minor loss in discrimination power, leads to no essential difference in the interpretation concerning chronic excessive alcohol consumption and is suitable to confirm EtG results in abstinence assessment if ethanol containing hair sprays or lotions are excluded. Copyright © 2017 Elsevier B

  11. Rwanda: Background and Current Developments

    DTIC Science & Technology

    2011-04-29

    1994, the presidents of Rwanda and Burundi , along with several senior government officials, were killed when their plane was shot down as it approached...the presidents of Rwanda and Burundi , along with several senior government officials, were killed when their plane was shot down as it approached...Roman Catholic: 56.5%, Protestant: 26%, Adventist: 11.1%, Muslim: 4.6% GDP -Purchasing power parity: $11.08 billion (2010) GDP per capita: $1,100

  12. Rwanda: Background and Current Developments

    DTIC Science & Technology

    2010-08-03

    FDLR of committing serious atrocities against civilians in Luofu, a town north of Goma . In October 2008, the forces of the CNDP launched a major...retreated in large numbers. The U.N. Mission in Congo (MONUC) also withdrew from some areas and pulled most of its forces into Goma . In late October...General Nkunda declared a unilateral cease- fire and ordered his forces to remain outside Goma . The cease-fire has been violated in recent weeks by

  13. Rwanda: Background and Current Developments

    DTIC Science & Technology

    2010-02-04

    United Nations officials accused the FDLR of committing serious atrocities against civilians in Luofu, a town north of Goma . In October 2008, the...The U.N. Mission in Congo (MONUC) also withdrew from some areas and pulled most of its forces into Goma . In late October, General Nkunda declared a...unilateral cease- fire and ordered his forces to remain outside Goma . The cease-fire has been violated in recent weeks by both sides, although fighting

  14. Rwanda: Background and Current Developments

    DTIC Science & Technology

    2009-05-14

    a town north of Goma . In October 2008, the forces of the CNDP launched a major offensive against the Democratic Republic of Congo Armed Forces...also withdrew from some areas and pulled most of its forces into Goma . In late October, General Nkunda declared a unilateral cease- fire and ordered his...forces to remain outside Goma . The cease-fire has been violated in recent weeks by both sides, although fighting has not spread to other parts of

  15. Rwanda: Background and Current Developments

    DTIC Science & Technology

    2010-05-20

    accused the FDLR of committing serious atrocities against civilians in Luofu, a town north of Goma . In October 2008, the forces of the CNDP launched...Congolese forces retreated in large numbers. The U.N. Mission in Congo (MONUC) also withdrew from some areas and pulled most of its forces into Goma . In...late October, General Nkunda declared a unilateral cease- fire and ordered his forces to remain outside Goma . The cease-fire has been violated in

  16. Rwanda: Background and Current Developments

    DTIC Science & Technology

    2009-03-23

    areas and pulled most of its forces into Goma . In late October, General Nkunda declared a unilateral cease- fire and ordered his forces to remain...outside Goma . The cease-fire has been violated in recent weeks by both sides, although fighting has not spread to other parts of Congo. The DRC

  17. Rwanda: Background and Current Developments

    DTIC Science & Technology

    2010-10-08

    north of Goma . In October 2008, the forces of the CNDP launched a major offensive against the Democratic Republic of Congo Armed Forces (FARDC) in...withdrew from some areas and pulled most of its forces into Goma . In late October, General Nkunda declared a unilateral cease- fire and ordered his forces...to remain outside Goma . The cease-fire has been violated in recent weeks by both sides, although fighting has not spread to other parts of Congo

  18. Rwanda: Background and Current Developments

    DTIC Science & Technology

    2009-09-03

    in Luofu, a town north of Goma . In October 2008, the forces of the CNDP launched a major offensive against the Democratic Republic of Congo Armed...MONUC) also withdrew from some areas and pulled most of its forces into Goma . In late October, General Nkunda declared a unilateral cease- fire and...ordered his forces to remain outside Goma . The cease-fire has been violated in recent weeks by both sides, although fighting has not spread to other

  19. Rwanda: Background and Current Developments

    DTIC Science & Technology

    2008-12-04

    Congo (MONUC) also withdrew from some areas and pulled most of its forces into Goma . In late October, General Nkunda declared a unilateral cease-fire...and ordered his forces to remain outside Goma . The cease-fire has been violated in recent weeks by both sides, although fighting has not spread to

  20. Tanzania: Background and Current Conditions

    DTIC Science & Technology

    2010-07-23

    persons with albinism and women persisted. Female genital mutilation (FGM), especially of young girls, continued to be practiced. Trafficking in... Kenya and Uganda, of the East African Community (EAC), established by a 1999 treaty, which revived an earlier EAC, defunct since 1977. The EAC Treaty

  1. Controlling Charge and Current Neutralization of an Ion Beam Pulse in a Background Plasma by Application of a Solenoidal Magnetic Field I: Weak Magnetic Field Limit

    SciTech Connect

    Kaganovich, I. D., Startsev, E. A., Sefkow, A. B., Davidson, R. C.

    2008-10-10

    Propagation of an intense charged particle beam pulse through a background plasma is a common problem in astrophysics and plasma applications. The plasma can effectively neutralize the charge and current of the beam pulse, and thus provides a convenient medium for beam transport. The application of a small solenoidal magnetic field can drastically change the self-magnetic and self- electric fields of the beam pulse, thus allowing effective control of the beam transport through the background plasma. An analytic model is developed to describe the self-magnetic field of a finite- length ion beam pulse propagating in a cold background plasma in a solenoidal magnetic field. The analytic studies show that the solenoidal magnetic field starts to infuence the self-electric and self-magnetic fields when ωce > ωpeβb, where ωce = eβ/mec is the electron gyrofrequency, ωpe is the electron plasma frequency, and βb = Vb/c is the ion beam velocity relative to the speed of light. This condition typically holds for relatively small magnetic fields (about 100G). Analytical formulas are derived for the effective radial force acting on the beam ions, which can be used to minimize beam pinching. The results of analytic theory have been verified by comparison with the simulation results obtained from two particle-in-cell codes, which show good agreement.

  2. Current-polarized ion-selective membranes: The influence of plasticizer and lipophilic background electrolyte on concentration profiles, resistance, and voltage transients.

    PubMed

    Zook, Justin M; Langmaier, Jan; Lindner, Ernő

    2009-03-02

    Lipophilic background electrolytes consisting of a lipophilic cation and a lipophilic anion, such as tetradodecylammonium tetrakis(4-chlorophenyl) borate (ETH 500), or bis(triphenylphosphoranylidene) ammonium tetrakis[3,5bis(trifluoromethyl) phenyl] borate (BTPPATFPB) are incorporated into the membranes of ion-selective electrodes (ISEs) to improve the detection limit and selectivity of the electrodes and decrease the resistance of the sensing membrane. In this work, spectroelectrochemical microscopy (SpECM) is used in conjunction with chronopotentiometry to quantify the effects of a lipophilic background electrolyte on the concentration profiles induced inside current-polarized membranes and on the measured voltage transients in chronopotentiometric experiments. In agreement with the theoretical model, the lipophilic background electrolyte incorporated into o-NPOE or DOS plasticized membranes decreases the membrane resistance and thus the contribution of migration in the overall transport across ion-selective membranes. Consequently, it has a significant influence on the changing concentration profiles of the ion-ionophore complex during chronopotentiometric experiments.

  3. Portable acoustic myography – a realistic noninvasive method for assessment of muscle activity and coordination in human subjects in most home and sports settings

    PubMed Central

    Harrison, Adrian P; Danneskiold-Samsøe, Bente; Bartels, Else M

    2013-01-01

    Muscle sound gives a local picture of muscles involved in a particular movement and is independent of electrical signals between nerve and muscle. Sound recording (acoustic myography) is a well-known noninvasive technique that has suffered from not being easily applicable, as well as not being able to register at sufficient sampling speed. With modern amplifiers and digital sound recording this has changed, and such assessment during movement outside a laboratory setting may be possible. Our aim was to develop a setup for muscle-sound assessment, which could be reliably applied in any local setting. A group of healthy subjects were assessed during standing, stair climbing, walking, and running. Piezoelectric microphones were applied to the skin using contact gel. A digital sound recorder enabled sampling speeds of around 96,000 Hz. Surface electromyography was measured in parallel as a comparison. The recorded signals were assessed and described in terms of signal frequency (Hz) and peak-to-peak amplitude (mV) using Chart software. Bioimpedance of the involved muscles was measured. Sound recording was shown to be an easy noninvasive method for assessment of muscle function during movement with the possibility of being applied in most clinical, sports, and home settings. Muscle sound gives a representation of the work of each muscle group during a complex movement, illustrated here by a step test, which revealed both concentric and eccentric activity. The method in the presented new setup has great potential for assessment of function in patients with musculoskeletal complaints in out-of-clinic settings, as well as in sports. PMID:24303115

  4. Force Myography for Monitoring Grasping in Individuals with Stroke with Mild to Moderate Upper-Extremity Impairments: A Preliminary Investigation in a Controlled Environment.

    PubMed

    Sadarangani, Gautam P; Jiang, Xianta; Simpson, Lisa A; Eng, Janice J; Menon, Carlo

    2017-01-01

    There is increasing research interest in technologies that can detect grasping, to encourage functional use of the hand as part of daily living, and thus promote upper-extremity motor recovery in individuals with stroke. Force myography (FMG) has been shown to be effective for providing biofeedback to improve fine motor function in structured rehabilitation settings, involving isolated repetitions of a single grasp type, elicited at a predictable time, without upper-extremity movements. The use of FMG, with machine learning techniques, to detect and distinguish between grasping and no grasping, continues to be an active area of research, in healthy individuals. The feasibility of classifying FMG for grasp detection in populations with upper-extremity impairments, in the presence of upper-extremity movements, as would be expected in daily living, has yet to be established. We explore the feasibility of FMG for this application by establishing and comparing (1) FMG-based grasp detection accuracy and (2) the amount of training data necessary for accurate grasp classification, in individuals with stroke and healthy individuals. FMG data were collected using a flexible forearm band, embedded with six force-sensitive resistors (FSRs). Eight participants with stroke, with mild to moderate upper-extremity impairments, and eight healthy participants performed 20 repetitions of three tasks that involved reaching, grasping, and moving an object in different planes of movement. A validation sensor was placed on the object to label data as corresponding to a grasp or no grasp. Grasp detection performance was evaluated using linear and non-linear classifiers. The effect of training set size on classification accuracy was also determined. FMG-based grasp detection demonstrated high accuracy of 92.2% (σ = 3.5%) for participants with stroke and 96.0% (σ = 1.6%) for healthy volunteers using a support vector machine (SVM). The use of a training set that was 50% the size of

  5. Force Myography for Monitoring Grasping in Individuals with Stroke with Mild to Moderate Upper-Extremity Impairments: A Preliminary Investigation in a Controlled Environment

    PubMed Central

    Sadarangani, Gautam P.; Jiang, Xianta; Simpson, Lisa A.; Eng, Janice J.; Menon, Carlo

    2017-01-01

    There is increasing research interest in technologies that can detect grasping, to encourage functional use of the hand as part of daily living, and thus promote upper-extremity motor recovery in individuals with stroke. Force myography (FMG) has been shown to be effective for providing biofeedback to improve fine motor function in structured rehabilitation settings, involving isolated repetitions of a single grasp type, elicited at a predictable time, without upper-extremity movements. The use of FMG, with machine learning techniques, to detect and distinguish between grasping and no grasping, continues to be an active area of research, in healthy individuals. The feasibility of classifying FMG for grasp detection in populations with upper-extremity impairments, in the presence of upper-extremity movements, as would be expected in daily living, has yet to be established. We explore the feasibility of FMG for this application by establishing and comparing (1) FMG-based grasp detection accuracy and (2) the amount of training data necessary for accurate grasp classification, in individuals with stroke and healthy individuals. FMG data were collected using a flexible forearm band, embedded with six force-sensitive resistors (FSRs). Eight participants with stroke, with mild to moderate upper-extremity impairments, and eight healthy participants performed 20 repetitions of three tasks that involved reaching, grasping, and moving an object in different planes of movement. A validation sensor was placed on the object to label data as corresponding to a grasp or no grasp. Grasp detection performance was evaluated using linear and non-linear classifiers. The effect of training set size on classification accuracy was also determined. FMG-based grasp detection demonstrated high accuracy of 92.2% (σ = 3.5%) for participants with stroke and 96.0% (σ = 1.6%) for healthy volunteers using a support vector machine (SVM). The use of a training set that was 50% the size of

  6. Transportation of high-current ion and electron beams in the accelerator drift gap in the presence of an additional electron background

    NASA Astrophysics Data System (ADS)

    Karas', V. I.; Kornilov, E. A.; Manuilenko, O. V.; Tarakanov, V. P.; Fedorovskaya, O. V.

    2015-12-01

    The dynamics of a high-current ion beam propagating in the drift gap of a linear induction accelerator with collective focusing is studied using 3D numerical simulations in the framework of the full system of the Vlasov-Maxwell equations (code KARAT). The ion beam is neutralized by a comoving electron beam in the current density and, partially, in space charge, since the velocities of electrons and ions differ substantially. The dynamics of the high-current ion beam is investigated for different versions of additional neutralization of its space charge. It is established that, for a given configuration of the magnetic field and in the presence of a specially programmed injection of additional electrons from the boundary opposite to the ion injection boundary, the angular divergence of the ion beam almost vanishes, whereas the current of the ion beam at the exit from the accelerator drift gap changes insignificantly and the beam remains almost monoenergetic.

  7. Transportation of high-current ion and electron beams in the accelerator drift gap in the presence of an additional electron background

    SciTech Connect

    Karas’, V. I. Kornilov, E. A.; Manuilenko, O. V.; Tarakanov, V. P.; Fedorovskaya, O. V.

    2015-12-15

    The dynamics of a high-current ion beam propagating in the drift gap of a linear induction accelerator with collective focusing is studied using 3D numerical simulations in the framework of the full system of the Vlasov–Maxwell equations (code KARAT). The ion beam is neutralized by a comoving electron beam in the current density and, partially, in space charge, since the velocities of electrons and ions differ substantially. The dynamics of the high-current ion beam is investigated for different versions of additional neutralization of its space charge. It is established that, for a given configuration of the magnetic field and in the presence of a specially programmed injection of additional electrons from the boundary opposite to the ion injection boundary, the angular divergence of the ion beam almost vanishes, whereas the current of the ion beam at the exit from the accelerator drift gap changes insignificantly and the beam remains almost monoenergetic.

  8. Behavior of a high-temperature superconducting conductor on a round core cable at current ramp rates as high as 67.8 kA s-1 in background fields of up to 19 T

    NASA Astrophysics Data System (ADS)

    Michael, P. C.; Bromberg, L.; van der Laan, D. C.; Noyes, P.; Weijers, H. W.

    2016-04-01

    High temperature superconducting (HTS) conductor-on-round-core (CORC®) cables have been developed for use in power transmission systems and large high-field magnets. The use of high-current conductors for large-scale magnets reduces system inductance and limits the peak voltage needed for ramped field operation. A CORC® cable contains a large number of RE-Ba2Cu3O7-δ (RE = rare earth) (REBCO) coated conductors, helically wound in multiple layers on a thin, round former. Large-scale applications, such as fusion and accelerator magnets, require current ramp rates of several kilo-Amperes per second during pulsed operation. This paper presents results that demonstrate the electromagnetic stability of a CORC® cable during transient conditions. Measurements were performed at 4.2 K using a 1.55 m long CORC® cable in background fields of up to 19 T. Repeated current pulses in a background field of 19 T at current ramp rates of up to 67.8 kA s-1 to approximately 90% of the cable’s quench current at that field, did not show any sign of degradation in cable performance due to excessive ac loss or electromagnetic instability. The very high current ramp rates applied during these tests were used to compensate, to the extent possible, the limited cable length accommodated by the test facility, assuming that the measured results could be extrapolated to longer length cables operated at proportionally lower current ramp rates. No shift of the superconducting transition to lower current was measured when the current ramp rate was increased from 25 A s-1 to 67.8 kA s-1. These results demonstrate the viability of CORC® cables for use in low-inductance magnets that operate at moderate to high current ramp rates.

  9. HerMES: Current Cosmic Infrared Background Estimates Can Be Explained by Known Galaxies and Their Faint Companions at z < 4

    NASA Astrophysics Data System (ADS)

    Viero, M. P.; Moncelsi, L.; Quadri, R. F.; Béthermin, M.; Bock, J.; Burgarella, D.; Chapman, S. C.; Clements, D. L.; Conley, A.; Conversi, L.; Duivenvoorden, S.; Dunlop, J. S.; Farrah, D.; Franceschini, A.; Halpern, M.; Ivison, R. J.; Lagache, G.; Magdis, G.; Marchetti, L.; Álvarez-Márquez, J.; Marsden, G.; Oliver, S. J.; Page, M. J.; Pérez-Fournon, I.; Schulz, B.; Scott, Douglas; Valtchanov, I.; Vieira, J. D.; Wang, L.; Wardlow, J.; Zemcov, M.

    2015-08-01

    We report contributions to cosmic infrared background (CIB) intensities originating from known galaxies and their faint companions at submillimeter wavelengths. Using the publicly available UltraVISTA catalog and maps at 250, 350, and 500 μm from the Herschel Multi-tiered Extragalactic Survey, we perform a novel measurement that exploits the fact that uncataloged sources may bias stacked flux densities—particularly if the resolution of the image is poor—and intentionally smooth the images before stacking and summing intensities. By smoothing the maps we are capturing the contribution of faint (undetected in {K}S˜ 23.4) sources that are physically associated, or correlated, with the detected sources. We find that the cumulative CIB increases with increased smoothing, reaching 9.82 ± 0.78, 5.77 ± 0.43 and 2.32+/- 0.19 {{nWm}}-2 {{sr}}-1 at 250, 350, and 500 μm at 300 {arcsec} FWHM. This corresponds to a fraction of the fiducial CIB of 0.94 ± 0.23, 1.07 ± 0.31, and 0.97 ± 0.26 at 250, 350, and 500 μm, where the uncertainties are dominated by those of the absolute CIB. We then propose, with a simple model combining parametric descriptions for stacked flux densities and stellar mass functions, that emission from galaxies with log(M/{M}⊙ )\\gt 8.5 can account for most of the measured total intensities and argue against contributions from extended, diffuse emission. Finally, we discuss prospects for future survey instruments to improve the estimates of the absolute CIB levels, and observe any potentially remaining emission at z\\gt 4.

  10. 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.

  11. 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.

  12. [Informed consent. Historical background and current problems].

    PubMed

    Jensen, A B

    1990-11-26

    At present, informed consent is essential before patients can participate in clinical trials. The fact that a doctor asks the patient for informed consent is an expression of respect for the patient's right to make decisions about his own body. The request is made in recognition of the fact that optimal treatment can only be ensured by means of clinically controlled trials. The need for regulation of research arose at the beginning of the present century when pharmacological development accelerated. The Nürenberg Declaration was elaborated after the second world war and, subsequently, the Helsinki Declarations I and II. In these, directives are established for clinical research and for the rights of participants. A number of conditions make it difficult to fulfill these intentions. It may be difficult to ensure that the patient has adequate basic knowledge. The patient may feel that he is in a state of dependence on the doctor which influences his possibility to choose freely. Confidence between doctor and patient may be undermined if the patient is requested to participate in randomization for choice of treatment. Doctors know too little about how valid information can be ensured.

  13. The Background to Current Theories of Scuffing

    DTIC Science & Technology

    1973-01-01

    contact is that the local pressures are sufficiently high to cause significant elastic deformation of the surfaces. The actual pressures involved... deformation of the surfaces resulting from this pressure distribution was calculated using elasticity theory, and was compared with the inverse hydrodynamic...viscosity cf the lubricant was enhanced by pressure . This situation does not occur for low modulus materials, however, since in this case, on

  14. Backgrounder: Final Rule for Current Good Manufacturing ...

    Center for Food Safety and Applied Nutrition (CFSAN)

    ... History. ... Tiếng Việt | 한국어 | Tagalog | Русский | العربية | Kreyòl Ayisyen | Français | Polski | Português | Italiano | Deutsch | 日本語 | فارسی | English. ...

  15. Are South African Speech-Language Therapists adequately equipped to assess English Additional Language (EAL) speakers who are from an indigenous linguistic and cultural background? A profile and exploration of the current situation.

    PubMed

    Mdladlo, Thandeka; Flack, Penelope; Joubert, Robin

    2016-03-18

    This article presents the results of a survey conducted on Speech-Language Therapists (SLTs) regarding current practices in the assessment of English Additional Language (EAL) speakers in South Africa. It forms part of the rationale for a broader (PhD) study that critiques the use of assessment instruments on EAL speakers from an indigenous linguistic and cultural background. This article discusses an aspect of the broader research and presents the background, method, findings, discussion and implications of the survey. The results of this survey highlight the challenges of human and material resources to, and the dominance of English in, the profession in South Africa. The findings contribute to understanding critical factors for acquiring reliable and valid assessment results with diverse populations, particularly the implications from a cultural and linguistic perspective.

  16. Lattice QCD in Background Fields

    SciTech Connect

    William Detmold, Brian Tiburzi, Andre Walker-Loud

    2009-06-01

    Electromagnetic properties of hadrons can be computed by lattice simulations of QCD in background fields. We demonstrate new techniques for the investigation of charged hadron properties in electric fields. Our current calculations employ large electric fields, motivating us to analyze chiral dynamics in strong QED backgrounds, and subsequently uncover surprising non-perturbative effects present at finite volume.

  17. Backgrounds Data Center

    NASA Astrophysics Data System (ADS)

    Snyder, William A.; Gursky, Herbert; Heckathorn, Harry M.; Lucke, Bob L.; Dorland, Bryan N.; Kessel, R. A.; Berg, S. L.; Dombrowski, E. G.

    1994-09-01

    The Backgrounds Data Center (BDC) is the designated archive for backgrounds data collected by Ballistic Missile Defense Organization (BMDO) programs, some of which include ultraviolet sensors. Currently, the BDC holds ultraviolet data from the IBSS, UVPI, UVLIM, and FUVCAM sensors. The BDC will also be the prime archive for Midcourse Space Experiment (MSX) data and is prepared to negotiate with program managers to handle other datasets. The purpose of the BDC is to make data accessible to users and to assist them in analyzing it. The BDC maintains the Science Catalog Information Exchange System (SCIES) allowing remote users to log in, read or post notices about current programs, search the catalogs for datasets of interest, and submit orders for data. On-site facilities are also available for the analysis of data, and consist of VMS and UNIX workstations with access to software analysis packages such as IDL, IRAF, and Khoros. Either on-site or remotely, users can employ the BDC-developed graphical user interface called the Visual Interface for Space and Terrestrial Analysis (VISTA) to generate catalog queries and to display and analyze data. SCIES and VISTA permit nearly complete access to BDC services and capabilities without the need to be physically present at the data center.

  18. Cosmic microwave background theory.

    PubMed

    Bond, J R

    1998-01-06

    A long-standing goal of theorists has been to constrain cosmological parameters that define the structure formation theory from cosmic microwave background (CMB) anisotropy experiments and large-scale structure (LSS) observations. The status and future promise of this enterprise is described. Current band-powers in -space are consistent with a DeltaT flat in frequency and broadly follow inflation-based expectations. That the levels are approximately (10(-5))2 provides strong support for the gravitational instability theory, while the Far Infrared Absolute Spectrophotometer (FIRAS) constraints on energy injection rule out cosmic explosions as a dominant source of LSS. Band-powers at 100 suggest that the universe could not have re-ionized too early. To get the LSS of Cosmic Background Explorer (COBE)-normalized fluctuations right provides encouraging support that the initial fluctuation spectrum was not far off the scale invariant form that inflation models prefer: e.g., for tilted Lambda cold dark matter sequences of fixed 13-Gyr age (with the Hubble constant H0 marginalized), ns = 1.17 +/- 0.3 for Differential Microwave Radiometer (DMR) only; 1.15 +/- 0.08 for DMR plus the SK95 experiment; 1.00 +/- 0.04 for DMR plus all smaller angle experiments; 1.00 +/- 0.05 when LSS constraints are included as well. The CMB alone currently gives weak constraints on Lambda and moderate constraints on Omegatot, but theoretical forecasts of future long duration balloon and satellite experiments are shown which predict percent-level accuracy among a large fraction of the 10+ parameters characterizing the cosmic structure formation theory, at least if it is an inflation variant.

  19. Extragalactic Backgrounds after Planck

    NASA Astrophysics Data System (ADS)

    Dore, Olivier

    offers a direct probe of the relation between light and matter. We will also revisit long-standing questions such as the nature of the extragalactic gamma-ray background and the active galactic nuclei contribution to the CIB. The astrophysical implications of our program are quite unique and far-reaching. As such, this proposal is essential to NASA objectives. Cross-cutting among different frequencies, we will be able to analyze in a synergic way a huge amount of data from current NASA surveys and projects, and we will directly address three of the seven key questions identified in the Astro2010 report ``New Worlds, New Horizons in Astronomy and Astrophysics'' : What is the fossil record of galaxy assembly from the first stars to present?, What are the connections between dark and luminous matter? How do cosmic structures form and evolve?

  20. Cosmic Microwave Background

    NASA Astrophysics Data System (ADS)

    Mather, John; Hinshaw, Gary; Page, Lyman

    The cosmic microwave background (CMB) radiation, the relic of the early phases of the expanding universe, is bright, full of information, and difficult to measure. Along with the recession of galaxies and the primordial nucleosynthesis, it is one of the strongest signs that the Hot Big Bang Model of the universe is correct. It is brightest around 2 mm wavelength, has a temperature of T_{cmb} = 2.72548 ± 0.00057 K, and has a blackbody spectrum within 50 parts per million. Its spatial fluctuations (around 0.01% on 1{}^{circ } scales) are possibly the relics of quantum mechanical processes in the early universe, modified by processes up to the decoupling at a redshift of about 1,000 (when the primordial plasma became mostly transparent). In the cold dark matter (DM) model with cosmic acceleration (Λ CDM), the fluctuation statistics are consistent with the model of inflation and can be used to determine other parameters within a few percent, including the Hubble constant, the Λ constant, the densities of baryonic and dark matter, and the primordial fluctuation amplitude and power spectrum slope. In addition, the polarization of the fluctuations reveals the epoch of reionization at a redshift approximately twice that determined from the Gunn-Peterson trough due to optically thick Lyman α absorption in QSO spectra. It is of historic importance, and a testament to the unity of theory and experiment, that we now have a standard model of cosmology that is consistent with all of the observations.Current observational challenges include (1) improvement of the spectrum distortion measurements, especially at long wavelengths, where the measured background is unexpectedly bright; (2) the search for the B-mode polarization (the divergence-free part of the polarization map), arising from propagating gravitational waves; and (3) the extension of fluctuation measurements to smaller angular scales. Much more precise spectrum observations near 2 mm are likely and would test some

  1. Millimeter wave polarimetric background measurements

    NASA Astrophysics Data System (ADS)

    Wallace, H. B.; McGee, R. A.

    1985-10-01

    Millimeter wave sensor research over the past years has been directed toward the development of a feature space for targets and background that is disjoint over a broad range of parameters. The results have been mixed at best. The BRL program is directed toward the investigation of the polarization and frequency characteristics of various types of background. The data would be collected so as to provide both systems engineers and systems analysts a useful and general set of millimeter wave background maps for development of performance estimates of current and proposed weapon systems. This paper highlights some of the key features of the instrumentation and measurement parameters which the authors believe to be important in establishing the polarization and frequency characteristics of both benign and hostile terrain backgrounds.

  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. Current data on the background burden to the persistent organochlorine pollutants HCB, p,p'-DDE as well as PCB 138, PCB 153 and PCB 180 in plasma of the general population in Germany.

    PubMed

    Schettgen, Thomas; Alt, Anne; Esser, Andre; Kraus, Thomas

    2015-06-01

    Despite their long-term ban, persistent organochlorine compounds like hexachlorobenzene (HCB), p,p'-dichlorodiphenylethylene (DDE) as well as polychlorinated biphenyls (PCBs) are still of environmental concern. For the evaluation of potential occupational or environmental exposures to these substances, it is essential to know the current background burden of the general population. As representative and up-to-date information is missing for Germany, we have analysed a large dataset generated in studies on potential exposure to lower chlorinated PCBs to fill this gap for the levels of HCB, DDE as well as PCB 138, PCB 153 and PCB 180. We have investigated n=2750 plasma samples of persons of the general population living in North Rhine-Westfalia and Hesse aged 6-65 years and sampled between September 2010 and March 2014. For evaluation of the age-dependent accumulation in the general population we have generated seven age groups in the collective. Our laboratory used a validated and quality controlled procedure using GC/MS for quantification of the organochlorine compounds in plasma (LOQ: 0.01μg/L). The median (95th percentile) levels for ∑ PCB 138+PCB 153+PCB 180 were 0.14 (0.73); 0.30 (0.82); 0.38 (0.88); 0.50 (1.14); 0.92; 1.58 (3.54) and 2.41 (4.82)μg/L plasma in the age groups 6-10 years (n=102), 11-17 years (n=499), 18-25 years (n=157), 26-35 years (n=710), 36-45 years (n=400), 46-55 years (n=525) and 56-65 years (n=357), respectively. Similarly, the median (95th percentile) levels of p,p'-DDE were 0.18 (1.24); 0.18 (0.74); 0.24 (0.85); 0.30 (1.20); 0.45 (1.74); 0.64 (3.25) and 0.94 (4.7)μg/L plasma. Finally, the median (95th percentile) of HCB in plasma in these age groups was 0.05 (0.10); 0.06 (0.11); 0.08 (0.15); 0.08 (0.15); 0.11 (0.22); 0.14 (0.42) and 0.20 (0.68)μg/L plasma. Our results prove an overall substantial reduction in the body burden to organochlorine compounds in Germany compared to earlier studies. However, 15% and 3.6% of the examined

  4. 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)

  5. 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)

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Ambient background particulate composition, outdoor natural background: interferents/clutter

    NASA Astrophysics Data System (ADS)

    Paterno, Dorothea

    2012-06-01

    It has proven a very difficult task to discriminate an actual BW threat from the natural occurring ambient particulate aerosol, which includes a significant fraction of particles consisting of mixed mineral and biological material. The interferent particles [clutter] (bio and non bio) concentration varies widely both by location, weather and season and diurnally. Naturally occurring background particulates are composed of fungal and bacterial spores both fragments and components, plant fragments and debris, animal fragments and debris, all of which may be associated with inert dust or combustion material. Some or all of which could also be considered to be an interferent to a biological warfare detector and cause these biodector systems to cause False Alarms by non specific BW bio detectors. I will share analysis of current long term background data sets.

  13. Flat currents of the Green-Schwarz superstrings in AdS{sub 5}xS{sup 1} and AdS{sub 3}xS{sup 3} backgrounds

    SciTech Connect

    Chen Bin; He Yali; Song Xingchang; Zhang Peng

    2005-04-15

    We construct a one-parameter family of flat currents in AdS{sub 5}xS{sup 1} and AdS{sub 3}xS{sup 3} Green-Schwarz superstrings, which would naturally lead to a hierarchy of classical conserved nonlocal charges. In the former case we rewrite the AdS{sub 5}xS{sup 1} string using a new Z{sub 4}-graded base of the superalgebra su(2,2 vertical bar 2). In both cases the existence of the Z{sub 4} grading in the superalgebras plays a key role in the construction. As a result, we find that the flat currents, when formally written in terms of the G{sub 0}-gauge invariant lowercase 1-forms, take the same form as the one in the AdS{sub 5}xS{sup 5} case.

  14. 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.

  15. 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.

  16. 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.

  17. 25 CFR 556.4 - Background investigations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... of birth, citizenship, gender, all languages (spoken or written); (2) Currently and for the previous... conducting a background investigation, a tribe or its agents shall promise to keep confidential the identity...

  18. 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.

  19. 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,…

  20. 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.

  1. 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.

  2. 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…

  3. 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…

  4. 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,…

  5. Some background about satellites

    NASA Technical Reports Server (NTRS)

    Burns, Joseph A.

    1986-01-01

    Four tables of planetary and satellite data are presented which list satellite discoveries, planetary parameters, satellite orbits, and satellite physical properties respectively. A scheme for classifying the satellites is provided and it is noted that most known moons fall into three general classes: regular satellites, collisional shards, and irregular satellites. Satellite processes are outlined with attention given to origins, dynamical and thermal evolution, surface processes, and composition and cratering. Background material is provided for each family of satellites.

  6. Executive Summary: Background

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Background information on, and the objectives of, the NASA Global Biology Research Program are given. The following issues were addressed: (1) geographic distribution of wetland parameters, (2) the processes of wetland material fluxes, and (3) the relation of local fluxes with global processes. Wetland inventorying and categorizing, gas-phase exchanges with the atmosphere, material exchange with the aquatic environment, and material storage in wetland sediments were identified as topics requiring further research.

  7. Ultraviolet Background Radiation (Preprint)

    DTIC Science & Technology

    1991-03-01

    itself. A comprehensive summary of the observations is provided by Labov , Martin & Bowyer (59), and reviews of the relevant astronomy, which is...with William G. Fastie’s Apollo 17 experiment, our spurious background will translate into 0.2 units, which is negligible. If, on the other hand...grateful to all of my collaborators and supporters over the years, particularly Paul D. Feldman and William G. Fastie. Partial support for this

  8. [Use of gold implants as a treatment of pain related to canine hip dysplasia--a review. Part 1: Background and current state of research regarding the effects of implanting gold in tissue].

    PubMed

    Deisenroth, A; Nolte, I; Wefstaedt, P

    2013-01-01

    Gold-bead implantation as a method of pain treatment in dogs suffering from osteoarthritic disease is receiving increasing attention in veterinary medicine. For the present article, publications from veterinary books and journals were collected and evaluated, together with related articles in human medicine. After providing an overview of the historical use of gold and gold compounds, the technique of implanting this noble metal is introduced. The reasons for establishing the terms gold acupuncture and gold (bead) implantation are described, considering the question whether and what kind of methodological differences exist behind these terms. Next, previous publications concerning the effects of gold implantation in tissue are summarised. In 2002 it was proven that gold ions are released from the surface of gold implants by a process termed dissolucytosis. Subsequent publications further investigated details about the interaction between gold ions and tissue as well as the distribution pattern of bio-released ions. Gold compounds were previously used for chrysotherapy in human medicine until medication with fewer side effects became established. The anti-inflammatory and immuno-modulatory properties of gold compounds were used to treat rheumatoid arthritis. Current research aims to ascertain whether the anti-inflammatory and immuno-modulating effects of gold compounds are imitated by gold ions released from gold implants at a local level. In conclusion, the present review summarises important findings about the effects of gold implanted in tissue. However, further research is necessary to estimate the limitations and benefits of this auromedication.

  9. Cosmic Background Radiation

    NASA Astrophysics Data System (ADS)

    Sidharth, B. G.; Valluri, S. R.

    2015-08-01

    It is shown that a collection of photons with nearly the same frequency exhibits a "condensation" type of phenomenon corresponding to a peak intensity. The observed cosmic background radiation can be explained from this standpoint. We have obtained analogous results by extremization of the occupation number for photons with the use of the Lambert W function. Some of the interesting applications of this function are briefly discussed in the context of graphene which exhibits an interesting two dimensional structure with several characteristic properties and diverse practical applications.

  10. The Backgrounds Data Center

    NASA Technical Reports Server (NTRS)

    Snyder, W. A.; Gursky, H.; Heckathorn, H. M.; Lucke, R. L.; Berg, S. L.; Dombrowski, E. G.; Kessel, R. A.

    1993-01-01

    The Strategic Defense Initiative Organization has created data centers for midcourse, plumes, and backgrounds phenomenologies. The Backgrounds Data Center (BDC) has been designated as the prime archive for data collected by SDIO programs. The BDC maintains a Summary Catalog that contains 'metadata,' that is, information about data, such as when the data were obtained, what the spectral range of the data is, and what region of the Earth or sky was observed. Queries to this catalog result in a listing of all data sets (from all experiments in the Summary Catalog) that satisfy the specified criteria. Thus, the user can identify different experiments that made similar observations and order them from the BDC for analysis. On-site users can use the Science Analysis Facility (SAFE for this purpose. For some programs, the BDC maintains a Program Catalog, which can classify data in as many ways as desired (rather than just by position, time, and spectral range as in the Summary Catalog). For example, data sets could be tagged with such diverse parameters as solar illumination angle, signal level, or the value of a particular spectral ratio, as long as these quantities can be read from the digital record or calculated from it by the ingest program. All unclassified catalogs and unclassified data will be remotely accessible.

  11. [Arrhythmia and genetic background].

    PubMed

    Chinushi, Masaomi; Sato, Akinori

    2013-02-01

    Recent studies have demonstrated that genetic abnormalities associated with the regulation of myocardial ionic channels, receptors, transporters, cell membranous proteins etc, can create an arrhythmogenic substrate in some patients with structurally normal hearts, and these are called hereditary arrhythmic diseases. Various arrhythmic diseases (such as congenital long or short QT syndrome, Brugada syndrome, catecholamine-sensitive polymorphic ventricular tachycardia, arrhythmogenic right ventricular cardiomyopathy, early repolarization syndrome etc.) are categorized as hereditary arrhythmic diseases. Among them, we focused on long QT syndrome and Brugada syndrome in this review. In congenital long QT syndrome, either attenuation of the net outward current or augmentation of the net inward current is responsible for prolonging the myocardial action potential duration and QT interval on ECG. Premature ventricular beats triggered due to early after-depolarization infringe on the large spatial dispersion of ventricular repolarization and initiate polymorphic ventricular tachycardia with a specific form (torsade de pointes). Currently, thirteen genotypes in Romano-Ward syndrome and two genotypes in Jervell-Lange Nielsen syndrome have been reported. In Brugada syndrome, large transient outward current (Ito) creates a deep phase 1 notch in the action potential, especially at the epicardial myocardium of the right ventricular outflow tract. In combination with the delayed completion of repolarization and loss of the phase 2 dome in some epicardial myocardium in this area, coved-type ECG abnormality and ventricular fibrillation due to phase 2 reentry are believed to be induced in Brugada syndrome. Eleven genetic abnormalities are presently listed as a possible cause of Brugada syndrome.

  12. Cosmic Microwave Background Mapping

    NASA Astrophysics Data System (ADS)

    Verkhodanov, O. V.; Doroshkevich, A. G.

    2012-03-01

    The last decade of research in cosmology was connected with the ambitious experiments including space and ground base observations. Among the most impressive results of these investigations are the measurements of the cosmic microwave background (CMB) radiation like WMAP* and Planck. Exactly from the CMB studies, we have started the epoch of the precision cosmology when generally the values of cosmological parameters have been known and present research is devoted to improvement of the precision. These achievements are connected with both the creation of the new facilities in millimeter and submillimeter astronomy (e.g., satellites, receivers, antennas, computers) and development of the methods for the CMB data analysis. Actually, the process of data analysis contains several technical stages including 1. Registration of time-ordered data (TOD) 2. Pixelization of the CMB data - map preparation 3. Component separation 4. Map statistics analysis 5. Map - spherical harmonics transformation 6. C(l)-spectrum calculation and spectrum statistics analysis 7. Cosmological parameters estimation Starting from the cosmic background explorer (COBE) experiment using the so-called Quadrilateralized Sky Cube Projection (see [1-3]), the problem of the whole sky CMB pixelization has attracted great interest and many such schemes were developed. Let us note however that accurate pixelization of the CMB data on the sphere is very important but not the final step of analysis. Usually, the next step implies the determination of the coefficients of the spherical harmonic decomposition of the CMB signal for both anisotropy and polarization. This means that some of the pixelization schemes provide a very accurate map but are inconvenient for further decomposition. This also means that the choice of suitable pixelization schemes depends upon the general goals of the investigation. In this review, we consider several of the most popular sky map pixelization schemes and link them with the

  13. Background canceling surface alpha detector

    DOEpatents

    MacArthur, D.W.; Allander, K.S.; Bounds, J.A.

    1996-06-11

    A background canceling long range alpha detector which is capable of providing output proportional to both the alpha radiation emitted from a surface and to radioactive gas emanating from the surface. The detector operates by using an electrical field between first and second signal planes, an enclosure and the surface or substance to be monitored for alpha radiation. The first and second signal planes are maintained at the same voltage with respect to the electrically conductive enclosure, reducing leakage currents. In the presence of alpha radiation and radioactive gas decay, the signal from the first signal plane is proportional to both the surface alpha radiation and to the airborne radioactive gas, while the signal from the second signal plane is proportional only to the airborne radioactive gas. The difference between these two signals is proportional to the surface alpha radiation alone. 5 figs.

  14. Background canceling surface alpha detector

    DOEpatents

    MacArthur, Duncan W.; Allander, Krag S.; Bounds, John A.

    1996-01-01

    A background canceling long range alpha detector which is capable of providing output proportional to both the alpha radiation emitted from a surface and to radioactive gas emanating from the surface. The detector operates by using an electrical field between first and second signal planes, an enclosure and the surface or substance to be monitored for alpha radiation. The first and second signal planes are maintained at the same voltage with respect to the electrically conductive enclosure, reducing leakage currents. In the presence of alpha radiation and radioactive gas decay, the signal from the first signal plane is proportional to both the surface alpha radiation and to the airborne radioactive gas, while the signal from the second signal plane is proportional only to the airborne radioactive gas. The difference between these two signals is proportional to the surface alpha radiation alone.

  15. Deleterious background selection with recombination

    SciTech Connect

    Hudson, R.R.; Kaplan, N.L.

    1995-12-01

    An analytic expression for the expected nucleotide diversity is obtained for a neutral locus in a region with deleterious mutation and recombination. Our analytic results are used to predict levels of variation for the entire third chromosome of Drosophila melanogaster. The predictions are consistent with the low levels of variation that have been observed at loci near the centromeres of the third chromosome of D. melanogaster. However, the low levels of variation observed near the tips of this chromosome are not predicted using currently available estimates of the deleterious mutation rate and of selection coefficients. If considerably smaller selection coefficients are assumed, the low observed levels of variation at the tips of the third chromosome are consistent with the background selection model. 33 refs., 4 figs., 1 tab.

  16. Environmental Background Measurement Program.

    DTIC Science & Technology

    1985-02-15

    harmonic frequencies. In an effort to be quantity to use in studying this phenomena. In Fig. objective , the spacing of these reference lines has been 9b...waves, mesoseale eddies, and other phenomena. A current objective of considerable importance to both the Naval and the research communities is to...WAVENUMBER(CP) SLANT WAvENUMERCPM) 70 "t: UPWARD 70kNz DOWN WARID 3%1"ENERGY PROPAGATION a 01ENERGY PROPAGATION4 _jTP 06 F1 0 T1083 F1 I ~jj 03 0n0 ..) Cj

  17. Background Review and Current Concepts of Reperfusion Injury

    DTIC Science & Technology

    1990-11-01

    TERMS (C&ntnue on reverse Nf neceuaiy and ident b lck number) FIELD 1GROUP $S-GROUP Stroke, cerebral ischemia, free radicals , white cells, reperfusion...Subse- meostasis, free radical generation, leuko- essential to functional recovery and quently, other workers have impli- cyte-medlated injury, and...plugging of vessels,’" and free radical (Arch Neurol. 1990;47:1245-1254) be achieved by measures that counter- damage" in reperfusion injury of the act

  18. [Background and current status of bioethics in Colombia].

    PubMed

    Sánchez-Torres, F

    1990-01-01

    Rapid advances in medicine have placed modern-day man in a situation characterized by perplexity and dangerous confusion. At the same time, they have underscored the need to analyze such advances and evaluate their negative consequences for individuals and communities. As scientific and technological innovations reach developing countries such as Colombia, their incorporation into daily medical practice also prompts the need to examine their impact in the light of ethical principles. This article discusses issues related to organ transplantation, human reproduction, terminally ill patients, abortion, AIDS, and medical publications.

  19. Current Commitments under the GATS in Educational Services. Background Document.

    ERIC Educational Resources Information Center

    Organisation for Economic Cooperation and Development, Paris (France). Centre for Educational Research and Innovation.

    The GATS is a multilateral, legally enforceable agreement among members of the World Trade Organization (WTO) that regulates international trade services. Rules regulating internationally traded educational services, which include various types of exchange programs, are part of the agreement. Among the 42 member countries that have made…

  20. Comprehensive Nuclear-Test-Ban Treaty: Background and Current Developments

    DTIC Science & Technology

    2013-06-10

    over Russia.4 • On February 12, the IMS detected an unusual seismic event in North Korea, consistent with a nuclear test, which North Korea...45 It announced two more tests May 13. An academic study concluded, based on seismic data, that India and Pakistan overstated the number and yields...tests based on uncertain seismic evidence. Pakistan made no claims of testing fusion devices. Pakistan’s weapons program apparently relies heavily on

  1. The Reliable Replacement Warhead Program: Background and Current Developments

    DTIC Science & Technology

    2007-11-08

    Research Service, The Library of Congress,101 Independence Ave, SE,Washington,DC,20540- 7050 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING...subject to corrosion . Plastic-bonded high explosives and other plastics tend to decompose over extended periods of time.... portions of materials can...noted that nuclear weapons engineering has benefitted from a quarter century of experience in dealing with corrosion , deterioration, and creep since the

  2. Background of Civil Defense and Current Damage Limiting Studies.

    ERIC Educational Resources Information Center

    Romm, Joseph

    A brief history of civil defense administration precedes analysis of nuclear attack conditions and the influence of protective measures. Damage limitation procedure is explained in terms of--(1) blast effects, (2) radiation doses, (3) geographical fallout distribution patterns, and (4) national shelter needs. Major concept emphasis relates to--(1)…

  3. Comprehensive Nuclear-Test-Ban Treaty: Background and Current Developments

    DTIC Science & Technology

    2013-01-02

    69 James Sterngold, “U.S. Urges Sanctions to Restrain North Korea,” San Francisco Chronicle , October 10, 2006, p. 1. 70 Broad and Mazzetti, “Blast...million to underwrite the rebuilding of the hydroacoustic monitoring station on Crozet Island in the southern Indian Ocean .”159 The FY2013 request...is a gas gun that shoots a high-velocity projectile at a plutonium target to produce “high shock pressures, temperatures , and strain rates similar

  4. Comprehensive Nuclear-Test-Ban Treaty: Background and Current Developments

    DTIC Science & Technology

    2012-08-03

    continued) 10, 2006, p. 8. 65 James Sterngold, “U.S. Urges Sanctions to Restrain North Korea,” San Francisco Chronicle , October 10, 2006, p. 1. 66...the hydroacoustic monitoring station on Crozet Island in the southern Indian Ocean .”153 The FY2013 request stated, “The voluntary contribution to...high-velocity projectile at a plutonium target to produce “high shock pressures, temperatures , and strain rates similar to that of a nuclear weapon

  5. The English Profile Programme: Background, Current Issues and Future Prospects

    ERIC Educational Resources Information Center

    Saville, Nick

    2010-01-01

    The EPP is a collaborative programme of interdisciplinary research, whose goal is to provide a set of Reference Level Descriptions (RLDs) for English for all six levels of the CEFR (Council of Europe 2001; Little 2006), from A1 to C2.

  6. The Democratic Republic of Congo: Background and Current Developments

    DTIC Science & Technology

    2011-04-29

    States has been actively engaged in facilitating the Tripartite Plus talks among the four key players in the Great Lakes region: Rwanda, DRC, Burundi ...French (official) GDP (purchasing power parity): $22.9 billion (2010) GDP per capita: $300 (2010) Source: CIA, The World Factbook, 2011 The...facilitating Tripartite Plus talks among the key regional players: DRC, Rwanda, Uganda, and Burundi . The parties agreed that the most serious threat to

  7. The Democratic Republic of Congo: Background and Current Developments

    DTIC Science & Technology

    2010-02-04

    Sese Seko began in the city of Goma in the mid-1990s. The second rebellion in the late 1990s began also in eastern Congo. The root causes of the...August 2009, Secretary of State Hillary Clinton visited Kinshasa and Goma in eastern Congo. At a press conference with Foreign Minister Alexis...against civilians in Luofu, a town north of Goma . According to the June 2009 U.N. Secretary General report, “the overall situation in the

  8. The Reliable Replacement Warhead Program: Background and Current Developments

    DTIC Science & Technology

    2008-07-23

    yield of the primary, another system injects “boost gas” — a mixture of deuterium and tritium (isotopes of hydrogen) gases — into the pit before the...Savannah River Site, another nuclear weapons plant, is not involved in the POG because it does not design warhead components; its role is to supply tritium ...nonnuclear components; Savannah River Site (SC), which processes tritium from stockpiled weapons to remove decay products; Pantex Plant (TX), which

  9. The Reliable Replacement Warhead Program: Background and Current Developments

    DTIC Science & Technology

    2008-09-12

    Testing Issues. 99th Cong., 2nd sess., Senate Hearing 99-937, 1986, pp. 167-168. 18 Ray Kidder, Stockpile Reliability and Nuclear Test Bans...Services Committee, April 4, 2005, p. 3. 24 Letter from Norris Bradbury , J. Carson Mark, and Richard Garwin to President Jimmy Carter, August 15, 1978

  10. The Reliable Replacement Warhead Program: Background and Current Developments

    DTIC Science & Technology

    2008-05-28

    1986, pp. 167-168. 16 Ray Kidder, Stockpile Reliability and Nuclear Test Bans: Response to J.W. Rosengren’s Defense of His 1983 Report, Lawrence...from Norris Bradbury , J. Carson Mark, and Richard Garwin to President Jimmy Carter, August 15, 1978, reprinted in U.S. Congress, House Committee on

  11. The Reliable Replacement Warhead Program: Background and Current Developments

    DTIC Science & Technology

    2008-05-19

    can change in character....15 CRS-5 15 (...continued) Hearing 99-937, 1986, pp. 167-168. 16 Ray Kidder, Stockpile Reliability and Nuclear Test Bans...worker’s environment acceptable until now for the use of CRS-7 22 Letter from Norris Bradbury , J. Carson Mark, and Richard Garwin to President Jimmy Carter

  12. The Reliable Replacement Warhead Program: Background and Current Developments

    DTIC Science & Technology

    2007-07-26

    Committee on Foreign Relations. Nuclear Testing Issues. 99th Cong., 2nd sess., Senate Hearing 99-937, 1986, pp. 167-168. 15 Ray Kidder, Stockpile...statement to Senate Armed Services Committee, April 4, 2005, p. 3. 21 Letter from Norris Bradbury , J. Carson Mark, and Richard Garwin to President Jimmy

  13. The Reliable Replacement Warhead Program: Background and Current Developments

    DTIC Science & Technology

    2007-05-11

    Committee on Foreign Relations. Nuclear Testing Issues. 99th Cong., 2nd sess., Senate Hearing 99-937, 1986, pp. 167-168. 14 Ray Kidder, Stockpile...Letter from Norris Bradbury , J. Carson Mark, and Richard Garwin to President Jimmy Carter, August 15, 1978, reprinted in U.S. Congress, House Committee

  14. The Reliable Replacement Warhead Program: Background and Current Developments

    DTIC Science & Technology

    2009-07-27

    Cong., 2nd sess., Senate Hearing 99-937, 1986, pp. 167-168. 18 Ray Kidder, Stockpile Reliability and Nuclear Test Bans: Response to J.W. Rosengren’s...24 Letter from Norris Bradbury , J. Carson Mark, and Richard Garwin to President Jimmy Carter, August 15, 1978, reprinted

  15. The Reliable Replacement Warhead Program: Background and Current Developments

    DTIC Science & Technology

    2007-12-18

    Senate Hearing 99-937, 1986, pp. 167-168. 15 Ray Kidder, Stockpile Reliability and Nuclear Test Bans: Response to J.W. Rosengren’s Defense of His...April 4, 2005, p. 3. 21 Letter from Norris Bradbury , J. Carson Mark, and Richard Garwin to President Jimmy Carter, August 15, 1978, reprinted in U.S

  16. The Reliable Replacement Warhead Program: Background and Current Developments

    DTIC Science & Technology

    2007-09-18

    on Foreign Relations. Nuclear Testing Issues. 99th Cong., 2nd sess., Senate Hearing 99-937, 1986, pp. 167-168. 16 Ray Kidder, Stockpile Reliability...Senate Armed Services Committee, April 4, 2005, p. 3. 22 Letter from Norris Bradbury , J. Carson Mark, and Richard Garwin to President Jimmy Carter, August

  17. The cosmic background explorer

    SciTech Connect

    Gulkis, G. ); Lubin, P.M. ); Meyer, S.S. ); Silverberg, R.F.

    1990-01-01

    Late last year the National Aeronautics and Space Administration launched its first satellite dedicated to the study of phenomena related to the origins of the universe. The satellite, called the Cosmic Background Explorer (COBE), carries three complementary detectors that will make fundamental measurements of the celestial radiation. Part of that radiation is believed to have originated in processes that occurred at the very dawn of the universe. By measuring the remnant radiation at wavelengths from one micrometer to one centimeter across the entire sky, scientists hope to be able to solve many mysteries regarding the origin and evolution of the early universe. Unfortunately, these radiative relics of the early universe are weak and veiled by local astrophysical and terrestrial sources of radiation. The wavelengths of the various cosmic components may also overlap, thereby making the understanding of the diffuse celestial radiation a challenge. Nevertheless, the COBE instruments, with their full-sky coverage, high sensitivity to a wide range of wavelengths and freedom from interference from the earth's atmosphere, will constitute for astrophysicists an observatory of unprecedented sensitivity and scope. The interesting cosmic signals will then be separated from one another and from noncosmic radiation sources by a comprehensive analysis of the data.

  18. Background sources in optical communications

    NASA Technical Reports Server (NTRS)

    Vilnrotter, V. A.

    1983-01-01

    The characterization and measurement of background radiation relevant to optical communications system performance is addressed. The necessary optical receiver parameters are described, and radiometric concepts required for the calculation of collected background power are developed. The most important components of optical background power are discussed, and their contribution to the total collected background power in various communications scenarios is examined.

  19. Integrable Background Geometries

    NASA Astrophysics Data System (ADS)

    Calderbank, David M. J.

    2014-03-01

    This work has its origins in an attempt to describe systematically the integrable geometries and gauge theories in dimensions one to four related to twistor theory. In each such dimension, there is a nondegenerate integrable geometric structure, governed by a nonlinear integrable differential equation, and each solution of this equation determines a background geometry on which, for any Lie group G, an integrable gauge theory is defined. In four dimensions, the geometry is selfdual conformal geometry and the gauge theory is selfdual Yang-Mills theory, while the lower-dimensional structures are nondegenerate (i.e., non-null) reductions of this. Any solution of the gauge theory on a k-dimensional geometry, such that the gauge group H acts transitively on an ℓ-manifold, determines a (k+ℓ)-dimensional geometry (k+ℓ≤4) fibering over the k-dimensional geometry with H as a structure group. In the case of an ℓ-dimensional group H acting on itself by the regular representation, all (k+ℓ)-dimensional geometries with symmetry group H are locally obtained in this way. This framework unifies and extends known results about dimensional reductions of selfdual conformal geometry and the selfdual Yang-Mills equation, and provides a rich supply of constructive methods. In one dimension, generalized Nahm equations provide a uniform description of four pole isomonodromic deformation problems, and may be related to the {SU}(∞) Toda and dKP equations via a hodograph transformation. In two dimensions, the {Diff}(S^1) Hitchin equation is shown to be equivalent to the hyperCR Einstein-Weyl equation, while the {SDiff}(Σ^2) Hitchin equation leads to a Euclidean analogue of Plebanski's heavenly equations. In three and four dimensions, the constructions of this paper help to organize the huge range of examples of Einstein-Weyl and selfdual spaces in the literature, as well as providing some new ! ones. The nondegenerate reductions have a long ancestry. More ! recently

  20. Computer Software & Intellectual Property. Background Paper.

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. Office of Technology Assessment.

    This background paper reviews copyright, patent, and trade secret protections as these issues are related to computer software. Topics discussed include current issues regarding legal protection for computer software including the necessity for defining intellectual property, determining what should or should not be protected, commerical piracy,…

  1. Computer Software & Intellectual Property. Background Paper.

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. Office of Technology Assessment.

    This background paper reviews copyright, patent, and trade secret protections as these issues are related to computer software. Topics discussed include current issues regarding legal protection for computer software including the necessity for defining intellectual property, determining what should or should not be protected, commerical piracy,…

  2. Background Light Bluer Than Expected

    NASA Image and Video Library

    2014-11-06

    This plot shows data from the Cosmic Infrared Background Experiment, or CIBER, rockets launched in 2010 and 2012. The experiment measures a diffuse glow of infrared light in the sky, known as the cosmic infrared background.

  3. Expected background in the LZ experiment

    SciTech Connect

    Kudryavtsev, Vitaly A.

    2015-08-17

    The LZ experiment, featuring a 7-tonne active liquid xenon target, is aimed at achieving unprecedented sensitivity to WIMPs with the background expected to be dominated by astrophysical neutrinos. To reach this goal, extensive simulations are carried out to accurately calculate the electron recoil and nuclear recoil rates in the detector. Both internal (from target material) and external (from detector components and surrounding environment) backgrounds are considered. A very efficient suppression of background rate is achieved with an outer liquid scintillator veto, liquid xenon skin and fiducialisation. Based on the current measurements of radioactivity of different materials, it is shown that LZ can achieve the reduction of a total background for a WIMP search down to about 2 events in 1000 live days for 5.6 tonne fiducial mass.

  4. Beam induced backgrounds: CDF experience

    SciTech Connect

    Tesarek, R.J.; /Fermilab

    2008-05-01

    We summarize the experiences of the Collider Detector at Fermilab (CDF) experiment in the presence of backgrounds originating from the counter circulating beams in the Fermilab Tevatron. These backgrounds are measured and their sources identified. Finally, we outline the strategies employed to reduce the effects of these backgrounds on the experiment.

  5. Sources of the Radio Background Considered

    SciTech Connect

    Singal, J.; Stawarz, L.; Lawrence, A.; Petrosian, V.; /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., Appl. Phys. Dept.

    2011-08-22

    We investigate possible origins of the extragalactic radio background reported by the ARCADE 2 collaboration. The surface brightness of the background is several times higher than that which would result from currently observed radio sources. We consider contributions to the background from diffuse synchrotron emission from clusters and the intergalactic medium, previously unrecognized flux from low surface brightness regions of radio sources, and faint point sources below the flux limit of existing surveys. By examining radio source counts available in the literature, we conclude that most of the radio background is produced by radio point sources that dominate at sub {mu}Jy fluxes. We show that a truly diffuse background produced by elections far from galaxies is ruled out because such energetic electrons would overproduce the observed X-ray/{gamma}-ray background through inverse Compton scattering of the other photon fields. Unrecognized flux from low surface brightness regions of extended radio sources, or moderate flux sources missed entirely by radio source count surveys, cannot explain the bulk of the observed background, but may contribute as much as 10%. We consider both radio supernovae and radio quiet quasars as candidate sources for the background, and show that both fail to produce it at the observed level because of insufficient number of objects and total flux, although radio quiet quasars contribute at the level of at least a few percent. We conclude that the most important population for production of the background is likely ordinary starforming galaxies above redshift 1 characterized by an evolving radio far-infrared correlation, which increases toward the radio loud with redshift.

  6. Background

    NASA Technical Reports Server (NTRS)

    1976-01-01

    An analysis was made of the UF6 fueled gas core reactor as a function of cavity reactor criticality and fluid mechanics tests, investigations of uranium optical emission spectra, and radiant heat transfer power plant studies. Data are also given on nuclear and thermodynamic cycle analysis.

  7. Diffuse Cosmic Infrared Background Radiation

    NASA Technical Reports Server (NTRS)

    Dwek, Eli

    2002-01-01

    The diffuse cosmic infrared background (CIB) consists of the cumulative radiant energy released in the processes of structure formation that have occurred since the decoupling of matter and radiation following the Big Bang. In this lecture I will review the observational data that provided the first detections and limits on the CIB, and the theoretical studies explaining the origin of this background. Finally, I will also discuss the relevance of this background to the universe as seen in high energy gamma-rays.

  8. Diffuse Cosmic Infrared Background Radiation

    NASA Technical Reports Server (NTRS)

    Dwek, Eli

    2002-01-01

    The diffuse cosmic infrared background (CIB) consists of the cumulative radiant energy released in the processes of structure formation that have occurred since the decoupling of matter and radiation following the Big Bang. In this lecture I will review the observational data that provided the first detections and limits on the CIB, and the theoretical studies explaining the origin of this background. Finally, I will also discuss the relevance of this background to the universe as seen in high energy gamma-rays.

  9. Gravitational wave background from binary systems

    SciTech Connect

    Rosado, Pablo A.

    2011-10-15

    Basic aspects of the background of gravitational waves and its mathematical characterization are reviewed. The spectral energy density parameter {Omega}(f), commonly used as a quantifier of the background, is derived for an ensemble of many identical sources emitting at different times and locations. For such an ensemble, {Omega}(f) is generalized to account for the duration of the signals and of the observation, so that one can distinguish the resolvable and unresolvable parts of the background. The unresolvable part, often called confusion noise or stochastic background, is made by signals that cannot be either individually identified or subtracted out of the data. To account for the resolvability of the background, the overlap function is introduced. This function is a generalization of the duty cycle, which has been commonly used in the literature, in some cases leading to incorrect results. The spectra produced by binary systems (stellar binaries and massive black hole binaries) are presented over the frequencies of all existing and planned detectors. A semi-analytical formula for {Omega}(f) is derived in the case of stellar binaries (containing white dwarfs, neutron stars or stellar-mass black holes). Besides a realistic expectation of the level of background, upper and lower limits are given, to account for the uncertainties in some astrophysical parameters such as binary coalescence rates. One interesting result concerns all current and planned ground-based detectors (including the Einstein Telescope). In their frequency range, the background of binaries is resolvable and only sporadically present. In other words, there is no stochastic background of binaries for ground-based detectors.

  10. 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.

  11. 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.

  12. Computerized Placement Tests: Background Readings.

    ERIC Educational Resources Information Center

    College Entrance Examination Board, Princeton, NJ.

    This document is a compilation of background readings for the user of Computerized Placement Tests (CPTs) developed by the College Board for student placement purposes. CPTs are computerized adaptive tests that test the individual abilities and backgrounds of examinees. CPTs are part of the ACCUPLACER student information management system. The…

  13. Background events in microchannel plates

    NASA Technical Reports Server (NTRS)

    Siegmund, O. H. W.; Vallerga, J.; Wargelin, B.

    1988-01-01

    Measurements have been made to assess the characteristics and origins of background events in microchannel plates (MCPs). An overall background rate of about 0.4 events/sq cm persec has been achieved consistently for MCPs that have been baked and scrubbed. The temperature and gain of the MCPs are found to have no significant effect on the background rate. Detection of 1.46-MeV gamma rays from the MCP glass confirms the presence of K-40, with a concentration of 0.0007 percent, in MCP glass. It is shown that beta decay from K-40 is sufficient to cause the background rate and spectrum observed. Anticoincidence measurements indicate the the background rate caused by cosmic ray interactions is small (less than 0.016 events/sq cm per sec).

  14. Background events in microchannel plates

    NASA Technical Reports Server (NTRS)

    Siegmund, O. H. W.; Vallerga, J.; Wargelin, B.

    1988-01-01

    Measurements have been made to assess the characteristics and origins of background events in microchannel plates (MCPs). An overall background rate of about 0.4 events/sq cm persec has been achieved consistently for MCPs that have been baked and scrubbed. The temperature and gain of the MCPs are found to have no significant effect on the background rate. Detection of 1.46-MeV gamma rays from the MCP glass confirms the presence of K-40, with a concentration of 0.0007 percent, in MCP glass. It is shown that beta decay from K-40 is sufficient to cause the background rate and spectrum observed. Anticoincidence measurements indicate the the background rate caused by cosmic ray interactions is small (less than 0.016 events/sq cm per sec).

  15. Background estimation in experimental spectra

    SciTech Connect

    Fischer, R.; Hanson, K. M.; Dose, V.; Linden, W. von der

    2000-02-01

    A general probabilistic technique for estimating background contributions to measured spectra is presented. A Bayesian model is used to capture the defining characteristics of the problem, namely, that the background is smoother than the signal. The signal is allowed to have positive and/or negative components. The background is represented in terms of a cubic spline basis. A variable degree of smoothness of the background 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 and allows uncertainties in the background to be estimated. Our technique is demonstrated on a particle induced x-ray emission spectrum from a geological sample and an Auger spectrum from iron, which contains signals with both positive and negative components. (c) 2000 The American Physical Society.

  16. BOOK REVIEW: The Cosmic Microwave Background The Cosmic Microwave Background

    NASA Astrophysics Data System (ADS)

    Coles, Peter

    2009-08-01

    With the successful launch of the European Space Agency's Planck satellite earlier this year the cosmic microwave background (CMB) is once again the centre of attention for cosmologists around the globe. Since its accidental discovery in 1964 by Arno Penzias and Robert Wilson, this relic of the Big Bang has been subjected to intense scrutiny by generation after generation of experiments and has gradually yielded up answers to the deepest questions about the origin of our Universe. Most recently, the Wilkinson Microwave Anisotropy Probe (WMAP) has made a full-sky analysis of the pattern of temperature and polarization variations that helped establish a new standard cosmological model, confirmed the existence of dark matter and dark energy, and provided strong evidence that there was an epoch of primordial inflation. Ruth Durrer's book reflects the importance of the CMB for future developments in this field. Aimed at graduate students and established researchers, it consists of a basic introduction to cosmology and the theory of primordial perturbations followed by a detailed explanation of how these manifest themselves as measurable variations in the present-day radiation field. It then focuses on the statistical methods needed to obtain accurate estimates of the parameters of the standard cosmological model, and finishes with a discussion of the effect of gravitational lensing on the CMB and on the evolution of its spectrum. The book apparently grew out of various lecture notes on CMB anisotropies for graduate courses given by the author. Its level and scope are well matched to the needs of such an audience and the presentation is clear and well-organized. I am sure that this book will be a useful reference for more senior scientists too. If I have a criticism, it is not about what is in the book but what is omitted. In my view, one of the most exciting possibilities for future CMB missions, including Planck, is the possibility that they might discover physics

  17. Low background counting at the LBNL low background facility

    SciTech Connect

    Thomas, K. J.; Norman, E. B.; Smith, A. R.; Chan, Y. D.; Hurley, D. L.; Wang, B. S.

    2013-08-08

    The Low Background Facility (LBF) at the Lawrence Berkeley National Laboratory (LBNL) in Berkeley, California provides low background gamma spectroscopy services to end-users in two unique facilities: locally within a carefully-constructed, low background laboratory space; and a satellite underground station (600 m.w.e) in Oroville, CA. 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 and anthropogenic products, as well as active screening via neutron activation analysis for specific applications. A general overview of the facilities, services, and capabilities will be discussed. Recent activities will also be presented, including the recent installation of a 3π muon veto at the surface facility, cosmogenic activation studies of TeO{sub 2} for CUORE, and environmental monitoring of Fukushima fallout.

  18. Aluminum as a source of background in low background experiments

    NASA Astrophysics Data System (ADS)

    Majorovits, B.; Abt, I.; Laubenstein, M.; Volynets, O.

    2011-08-01

    Neutrinoless double beta decay would be a key to understanding the nature of neutrino masses. The next generation of High Purity Germanium experiments will have to be operated with a background rate of better than 10 -5 counts/(kg y keV) in the region of interest around the Q-value of the decay. Therefore, so far irrelevant sources of background have to be considered. The metalization of the surface of germanium detectors is in general done with aluminum. The background from the decays of 22Na, 26Al, 226Ra and 228Th introduced by this metalization is discussed. It is shown that only a special selection of aluminum can keep these background contributions acceptable.

  19. Argentina: Background and U.S. Relations

    DTIC Science & Technology

    2016-09-06

    Islands (Islas Malvinas) war with Great Britain in 1982, and the country returned to civilian democratic rule with the election of Raúl Alfonsín of the...Estimate Report on Foreign Trade Barriers , the Macri government has taken steps to reverse many of Argentina’s restrictive trade policies imposed under...previous governments. The 2016 report provides background on Argentina’s current technical, sanitary, and phytosanitary barriers to U.S. imports

  20. 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.

  1. Investigation of the backgrounds in the EXO-200 experiment

    NASA Astrophysics Data System (ADS)

    Didberidze, Tamar; EXO-200 Collaboration

    2015-04-01

    The Enriched Xenon Observatory EXO-200 experiment currently located at Waste Isolation Pilot Plant (WIPP) in New Mexico, which uses a 175 kg of isotopically enriched 136 Xe, is designed to search for the neutrinoless double beta decay (0 νββ) in 136 Xe. The search for this type of decay requires a good understanding of background sources. I will present results of the background study done for the EXO-200 experiment. The study has been performed using a current EXO-200 low-background data and model to estimate the location and magnitude of background sources and compared to the radio assay results that were obtained before detector construction.

  2. Greater need for background checks.

    PubMed

    Fiesta, J

    1999-11-01

    The push is on for a more uniform system of background checks for health care employees. Studies and crimes against patients have prompted regulation by the Health Care Financing Administration (HCFA), state governments, hospitals, and Congress.

  3. 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.

  4. Low Background Counting at LBNL

    NASA Astrophysics Data System (ADS)

    Smith, A. R.; Thomas, K. J.; Norman, E. B.; Chan, Y. D.; Lesko, K. T.; Hurley, D. L.

    The Low Background Facility (LBF) at Lawrence Berkeley National Laboratory 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 cave and remotely at an underground location that historically has operated underground in Oroville, CA, but has recently been relocated to 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, as well as active screening via Neutron Activation Analysis for specific applications. The LBF also provides hosting services for general R&D testing in low background environments on the surface or underground for background testing of detector systems or similar prototyping. A general overview of the facilities, services, and sensitivities is presented. Recent activities and upgrades will also be presented, such as the completion of a 3π anticoincidence shield at the surface station and environmental monitoring of Fukushima fallout. The LBF is open to any users for counting services or collaboration on a wide variety of experiments and projects.

  5. Low Background Counting at LBNL

    DOE PAGES

    Smith, A. R.; Thomas, K. J.; Norman, E. B.; ...

    2015-03-24

    The Low Background Facility (LBF) at Lawrence Berkeley National Laboratory 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 cave and remotely at an underground location that historically has operated underground in Oroville, CA, but has recently been relocated to 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)more » or common cosmogenic/anthropogenic products, as well as active screening via Neutron Activation Analysis for specific applications. The LBF also provides hosting services for general R&D testing in low background environments on the surface or underground for background testing of detector systems or similar prototyping. A general overview of the facilities, services, and sensitivities is presented. Recent activities and upgrades will also be presented, such as the completion of a 3π anticoincidence shield at the surface station and environmental monitoring of Fukushima fallout. The LBF is open to any users for counting services or collaboration on a wide variety of experiments and projects.« less

  6. Low Background Counting at LBNL

    SciTech Connect

    Smith, A. R.; Thomas, K. J.; Norman, E. B.; Chan, Y. D.; Lesko, K. T.; Hurley, D. L.

    2015-03-24

    The Low Background Facility (LBF) at Lawrence Berkeley National Laboratory 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 cave and remotely at an underground location that historically has operated underground in Oroville, CA, but has recently been relocated to 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, as well as active screening via Neutron Activation Analysis for specific applications. The LBF also provides hosting services for general R&D testing in low background environments on the surface or underground for background testing of detector systems or similar prototyping. A general overview of the facilities, services, and sensitivities is presented. Recent activities and upgrades will also be presented, such as the completion of a 3π anticoincidence shield at the surface station and environmental monitoring of Fukushima fallout. The LBF is open to any users for counting services or collaboration on a wide variety of experiments and projects.

  7. Acoustic myography compared to electromyography during isometric fatigue and recovery.

    PubMed

    Rodriquez, A A; Agre, J C; Knudtson, E R; Franke, T M; Ng, A V

    1993-02-01

    This study compared the acoustic (RMS-AMG) to electromyographic (RMS-EMG) signal, median frequency of EMG power spectrum (Fm), and quadriceps torque during isometric fatiguing contraction (FC) and recovery. Seven subjects were tested for strength (MVC) and then, on separate days, maintained 20%, 40%, or 80% MVC to exhaustion followed by MVC testing at regular intervals. Throughout FC, RMS-EMG significantly (P < 0.05) increased and Fm significantly (P < 0.05) decreased during all trials; RMS-AMG significantly (P < 0.05) increased only during the 20% and 40% trials. During recovery, MVC and RMS-EMG recovered most slowly after the 20% trial and most rapidly after the 80% trial; Fm and RMS-AMG recovered by 90 seconds after all trials. RMS-AMG reflects RMS-EMG during low but not high levels of FC. Recovery of strength is most depressed following FC at lower relative levels of torque. We conclude that RMS-AMG behaves differently than RMS-EMG, torque, and Fm during FC and recovery.

  8. The COMPTEL instrumental line background

    NASA Astrophysics Data System (ADS)

    Weidenspointner, G.; Varendorff, M.; Oberlack, U.; Morris, D.; Plüschke, S.; Diehl, R.; Kappadath, S. C.; McConnell, M.; Ryan, J.; Schönfelder, V.; Steinle, H.

    2001-03-01

    The instrumental line background of the Compton telescope COMPTEL onboard the Compton Gamma-Ray Observatory is due to the activation and/or decay of many isotopes. The major components of this background can be attributed to eight individual isotopes, namely 2D, 22Na, 24Na, 28Al, 40K, 52Mn, 57Ni, and 208Tl. The identification of instrumental lines with specific isotopes is based on the line energies as well as on the variation of the event rate with time, cosmic-ray intensity, and deposited radiation dose during passages through the South-Atlantic Anomaly. The characteristic variation of the event rate due to a specific isotope depends on its life-time, orbital parameters such as the altitude of the satellite above Earth, and the solar cycle. A detailed understanding of the background contributions from instrumental lines is crucial at MeV energies for measuring the cosmic diffuse gamma-ray background and for observing gamma -ray line emission in the interstellar medium or from supernovae and their remnants. Procedures to determine the event rate from each background isotope are described, and their average activity in spacecraft materials over the first seven years of the mission is estimated.

  9. 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.

  10. The projected background for the CUORE experiment

    NASA Astrophysics Data System (ADS)

    Alduino, C.; Alfonso, K.; Artusa, D. R.; Avignone, F. T.; Azzolini, O.; Banks, T. I.; Bari, G.; Beeman, J. W.; Bellini, F.; Benato, G.; Bersani, A.; Biassoni, M.; Branca, A.; Brofferio, C.; Bucci, C.; Camacho, A.; Caminata, A.; Canonica, L.; Cao, X. G.; Capelli, S.; Cappelli, L.; Carbone, L.; Cardani, L.; Carniti, P.; Casali, N.; Cassina, L.; Chiesa, D.; Chott, N.; Clemenza, M.; Copello, S.; Cosmelli, C.; Cremonesi, O.; Creswick, R. J.; Cushman, J. S.; D'Addabbo, A.; Dafinei, I.; Davis, C. J.; Dell'Oro, S.; Deninno, M. M.; Di Domizio, S.; Di Vacri, M. L.; Drobizhev, A.; Fang, D. Q.; Faverzani, M.; Fernandes, G.; Ferri, E.; Ferroni, F.; Fiorini, E.; Franceschi, M. A.; Freedman, S. J.; Fujikawa, B. K.; Giachero, A.; Gironi, L.; Giuliani, A.; Gladstone, L.; Gorla, P.; Gotti, C.; Gutierrez, T. D.; Haller, E. E.; Han, K.; Hansen, E.; Heeger, K. M.; Hennings-Yeomans, R.; Hickerson, K. P.; Huang, H. Z.; Kadel, R.; Keppel, G.; Kolomensky, Yu. G.; Leder, A.; Ligi, C.; Lim, K. E.; Ma, Y. G.; Maino, M.; Marini, L.; Martinez, M.; Maruyama, R. H.; Mei, Y.; Moggi, N.; Morganti, S.; Mosteiro, P. J.; Napolitano, T.; Nastasi, M.; Nones, C.; Norman, E. B.; Novati, V.; Nucciotti, A.; O'Donnell, T.; Ouellet, J. L.; Pagliarone, C. E.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pessina, G.; Pettinacci, V.; Piperno, G.; Pira, C.; Pirro, S.; Pozzi, S.; Previtali, E.; Rosenfeld, C.; Rusconi, C.; Sakai, M.; Sangiorgio, S.; Santone, D.; Schmidt, B.; Schmidt, J.; Scielzo, N. D.; Singh, V.; Sisti, M.; Smith, A. R.; Taffarello, L.; Tenconi, M.; Terranova, F.; Tomei, C.; Trentalange, S.; Vignati, M.; Wagaarachchi, S. L.; Wang, B. S.; Wang, H. W.; Welliver, B.; Wilson, J.; Winslow, L. A.; Wise, T.; Woodcraft, A.; Zanotti, L.; Zhang, G. Q.; Zhu, B. X.; Zimmermann, S.; Zucchelli, S.; Laubenstein, M.

    2017-08-01

    The Cryogenic Underground Observatory for Rare Events (CUORE) is designed to search for neutrinoless double beta decay of ^{130}Te with an array of 988 TeO_2 bolometers operating at temperatures around 10 mK. The experiment is currently being commissioned in Hall A of Laboratori Nazionali del Gran Sasso, Italy. The goal of CUORE is to reach a 90% C.L. exclusion sensitivity on the ^{130}Te decay half-life of 9 × 10^{25} years after 5 years of data taking. The main issue to be addressed to accomplish this aim is the rate of background events in the region of interest, which must not be higher than 10^{-2} counts/keV/kg/year. We developed a detailed Monte Carlo simulation, based on results from a campaign of material screening, radioassays, and bolometric measurements, to evaluate the expected background. This was used over the years to guide the construction strategies of the experiment and we use it here to project a background model for CUORE. In this paper we report the results of our study and our expectations for the background rate in the energy region where the peak signature of neutrinoless double beta decay of ^{130}Te is expected.

  11. Physiologic correlates to background noise acceptance

    NASA Astrophysics Data System (ADS)

    Tampas, Joanna; Harkrider, Ashley; Nabelek, Anna

    2001-05-01

    Acceptance of background noise can be evaluated by having listeners indicate the highest background noise level (BNL) they are willing to accept while following the words of a story presented at their most comfortable listening level (MCL). The difference between the selected MCL and BNL is termed the acceptable noise level (ANL). One of the consistent findings in previous studies of ANL is large intersubject variability in acceptance of background noise. This variability is not related to age, gender, hearing sensitivity, personality, type of background noise, or speech perception in noise performance. The purpose of the current experiment was to determine if individual differences in physiological activity measured from the peripheral and central auditory systems of young female adults with normal hearing can account for the variability observed in ANL. Correlations between ANL and various physiological responses, including spontaneous, click-evoked, and distortion-product otoacoustic emissions, auditory brainstem and middle latency evoked potentials, and electroencephalography will be presented. Results may increase understanding of the regions of the auditory system that contribute to individual noise acceptance.

  12. Gravitino condensation in fivebrane backgrounds

    NASA Astrophysics Data System (ADS)

    Kitazawa, Noriaki

    2002-04-01

    We calculate the tension of the D3-brane in the fivebrane background which is described by the exactly solvable SU(2)k×U(1) world-sheet conformal field theory with large Kač-Moody level k. The D3-brane tension is extracted from the amplitude of one closed string exchange between two parallel D3-branes, and the amplitude is calculated by utilizing the open-closed string duality. The tension of the D3-brane in the background does not coincide with the one in the flat space-time even in the flat space-time limit: k-->∞. The finite curvature effect should vanish in the flat space-time limit and only the topological effect can remain. Therefore, the deviation suggests the condensation of the gravitino and/or dilatino which has been expected in the fivebrane background as a gravitational instanton.

  13. Robust background modelling in DIALS

    PubMed Central

    Parkhurst, James M.; Winter, Graeme; Waterman, David G.; Fuentes-Montero, Luis; Gildea, Richard J.; Murshudov, Garib N.; Evans, Gwyndaf

    2016-01-01

    A method for estimating the background under each reflection during integration that is robust in the presence of pixel outliers is presented. The method uses a generalized linear model approach that is more appropriate for use with Poisson distributed data than traditional approaches to pixel outlier handling in integration programs. The algorithm is most applicable to data with a very low background level where assumptions of a normal distribution are no longer valid as an approximation to the Poisson distribution. It is shown that traditional methods can result in the systematic underestimation of background values. This then results in the reflection intensities being overestimated and gives rise to a change in the overall distribution of reflection intensities in a dataset such that too few weak reflections appear to be recorded. Statistical tests performed during data reduction may mistakenly attribute this to merohedral twinning in the crystal. Application of the robust generalized linear model algorithm is shown to correct for this bias. PMID:27980508

  14. Background simulations and shielding calculations

    NASA Astrophysics Data System (ADS)

    Kudryavtsev, Vitaly A.

    2011-04-01

    Key improvements in the sensitivity of the underground particle astrophysics experiments can only be achieved if the radiation causing background events in detectors is well understood and proper measures are taken to suppress it. The background radiation arising from radioactivity and cosmic-ray muons is discussed here together with the methods of its suppression. Different shielding designs are considered to attenuate gamma-rays and neutrons coming from radioactivity in rock and lab walls. Purity of materials used in detector construction is analysed and the background event rates due to the presence of radioactive isotopes in detector components are discussed. Event rates in detectors caused by muon-induced neutrons with and without active veto systems are presented leading to the requirements for the depth of an underground laboratory and the efficiency of the veto system.

  15. Background music and cognitive performance.

    PubMed

    Angel, Leslie A; Polzella, Donald J; Elvers, Greg C

    2010-06-01

    The present experiment employed standardized test batteries to assess the effects of fast-tempo music on cognitive performance among 56 male and female university students. A linguistic processing task and a spatial processing task were selected from the Criterion Task Set developed to assess verbal and nonverbal performance. Ten excerpts from Mozart's music matched for tempo were selected. Background music increased the speed of spatial processing and the accuracy of linguistic processing. The findings suggest that background music can have predictable effects on cognitive performance.

  16. Detector Background at Muon Colliders

    SciTech Connect

    Mokhov, N.V.; Striganov, S.I.; /Fermilab

    2011-09-01

    Physics goals of a Muon Collider (MC) can only be reached with appropriate design of the ring, interaction region (IR), high-field superconducting magnets, machine-detector interface (MDI) and detector. Results of the most recent realistic simulation studies are presented for a 1.5-TeV MC. It is shown that appropriately designed IR and MDI with sophisticated shielding in the detector have a potential to substantially suppress the background rates in the MC detector. The main characteristics of backgrounds are studied.

  17. Exotic branes and nongeometric backgrounds.

    PubMed

    de Boer, Jan; Shigemori, Masaki

    2010-06-25

    When string or M theory is compactified to lower dimensions, the U-duality symmetry predicts so-called exotic branes whose higher-dimensional origin cannot be explained by the standard string or M-theory branes. We argue that exotic branes can be understood in higher dimensions as nongeometric backgrounds or U folds, and that they are important for the physics of systems which originally contain no exotic charges, since the supertube effect generically produces such exotic charges. We discuss the implications of exotic backgrounds for black hole microstate (non-)geometries.

  18. Generative electronic background music system

    SciTech Connect

    Mazurowski, Lukasz

    2015-03-10

    In this short paper-extended abstract the new approach to generation of electronic background music has been presented. The Generative Electronic Background Music System (GEBMS) has been located between other related approaches within the musical algorithm positioning framework proposed by Woller et al. The music composition process is performed by a number of mini-models parameterized by further described properties. The mini-models generate fragments of musical patterns used in output composition. Musical pattern and output generation are controlled by container for the mini-models - a host-model. General mechanism has been presented including the example of the synthesized output compositions.

  19. Ion Beam Scattering by Background Helium

    NASA Astrophysics Data System (ADS)

    Grillet, Anne; Hughes, Thomas; Boerner, Jeremiah

    2015-11-01

    The presence of background gases can cause charged particle beams to become more diffuse due to scattering. Calculations for the transport of an ion beam have been performed using Aleph, a particle-in-cell plasma modeling code, and verified against a general envelop equation for charged particle beams. We have investigated the influence of background helium on the coherence and transmitted current of the ion beam. Collisions between ions and neutral particles were calculated assuming isotropic elastic scattering. Since this tends to predict larger scattering angles than are expected at high energies, these are conservative estimates for beam scattering. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration.

  20. Cosmology with the Cosmic Microwave Background

    NASA Astrophysics Data System (ADS)

    Souradeep, Tarun

    The standard model of cosmology must not only explain the dynamics of the homogeneous background universe, but also satisfactorily describe the perturbed universe - the generation, evolution and finally, the formation of large-scale structures in the universe. Cosmic microwave background (CMB) has been by far the most influential cosmological observation driving advances in current cosmology. Exquisite measurements from CMB experiments have seen the emergence of a concordant cosmological model. Besides precise determination of various parameters of the standard cosmological model, observations have also established some important basic tenets that underlie models of cosmology and structure formation in the universe. The article reviews this aspect of recent progress in cosmology for a general science reader.

  1. Measuring anisotropies in the cosmic neutrino background

    NASA Astrophysics Data System (ADS)

    Lisanti, Mariangela; Safdi, Benjamin R.; Tully, Christopher G.

    2014-10-01

    Neutrino capture on tritium has emerged as a promising method for detecting the cosmic neutrino background (C ν B ). We show that relic neutrinos are captured most readily when their spin vectors are antialigned with the polarization axis of the tritium nuclei and when they approach along the direction of polarization. As a result, C ν B observatories may measure anisotropies in the cosmic neutrino velocity and spin distributions by polarizing the tritium targets. A small dipole anisotropy in the C ν B is expected due to the peculiar velocity of the lab frame with respect to the cosmic frame and due to late-time gravitational effects. The PTOLEMY experiment, a tritium observatory currently under construction, should observe a nearly isotropic background. This would serve as a strong test of the cosmological origin of a potential signal. The polarized-target measurements may also constrain nonstandard neutrino interactions that would induce larger anisotropies and help discriminate between Majorana versus Dirac neutrinos.

  2. University Student Access and Success. Go8 Backgrounder 9

    ERIC Educational Resources Information Center

    Group of Eight (NJ1), 2009

    2009-01-01

    Group of Eight (Go8) universities currently provide a wide range of services and programs to facilitate access and support for students from disadvantaged backgrounds. However, Go8 Vice-Chancellors have also agreed to develop jointly a coordinated equity strategy to increase the participation and success of students from disadvantaged backgrounds.…

  3. Semiconductor Bolometers Give Background-Limited Performance

    NASA Technical Reports Server (NTRS)

    Goebel, John; McMurray, Robert

    2006-01-01

    Semiconductor bolometers that are capable of detecting electromagnetic radiation over most or all of the infrared spectrum and that give background-limited performance at operating temperatures from 20 to 300 K have been invented. The term background-limited performance as applied to a bolometer, thermopile, or other infrared detector signifies that the ability to detect infrared signals that originate outside the detector is limited primarily by thermal noise attributable to the background radiation generated external to the bolometer. The signal-to-noise ratios and detectivities of the bolometers and thermopiles available prior to this invention have been lower than those needed for background-limited performance by factors of about 100 and 10, respectively. Like other electrically resistive bolometers, a device according to the invention exhibits an increase in electrical resistance when heated by infrared radiation. Depending on whether the device is operated under the customary constant- current or constant-voltage bias, the increase in electrical resistance can be measured in terms of an increase in voltage across the device or a decrease in current through the device, respectively. In the case of a semiconductor bolometer, it is necessary to filter out visible and shorter-wavelength light that could induce photoconductivity and thereby counteract all or part of the desired infrared- induced increase in resistance. The basic semiconductor material of a bolometer according to the invention is preferably silicon doped with one or more of a number of elements, each of which confers a different variable temperature coefficient of resistance. Suitable dopants include In, Ga, S, Se, Te, B, Al, As, P, and Sb. The concentration of dopant preferably lies in the range between 0.1 and 1,000 parts per billion.

  4. Educational Choice. A Background Paper.

    ERIC Educational Resources Information Center

    Quality Education for Minorities Network, Washington, DC.

    This paper addresses school choice, one proposal to address parental involvement concerns, focusing on historical background, definitions, rationale for advocating choice, implementation strategies, and implications for minorities and low-income families. In the past, transfer payment programs such as tuition tax credits and vouchers were…

  5. A Little Background Music, Please.

    ERIC Educational Resources Information Center

    Giles, Martha Mead

    1991-01-01

    Background music could be used to provide a pleasant beginning for the school day, to help keep students quiet and relaxed in the school cafeteria at lunchtime, and to provide a midafternoon lift for bored and tired children. The most effective music pleases children without overly exciting them through jarring rhythms and loud dynamics. (nine…

  6. Cultural Change. Teacher Background Material.

    ERIC Educational Resources Information Center

    Georgia Univ., Athens. Anthropology Curriculum Project.

    This essay on cultural change is intended to provide background reading material for teachers using "The Changing World Today" or "Cultural Change in Mexico and the United States," two textbooks from the Anthropology Curriculum Project. The essay can also be used, however, as a high school semester course in anthropology or as…

  7. Teaching about Natural Background Radiation

    ERIC Educational Resources Information Center

    Al-Azmi, Darwish; Karunakara, N.; Mustapha, Amidu O.

    2013-01-01

    Ambient gamma dose rates in air were measured at different locations (indoors and outdoors) to demonstrate the ubiquitous nature of natural background radiation in the environment and to show that levels vary from one location to another, depending on the underlying geology. The effect of a lead shield on a gamma radiation field was also…

  8. Teaching about Natural Background Radiation

    ERIC Educational Resources Information Center

    Al-Azmi, Darwish; Karunakara, N.; Mustapha, Amidu O.

    2013-01-01

    Ambient gamma dose rates in air were measured at different locations (indoors and outdoors) to demonstrate the ubiquitous nature of natural background radiation in the environment and to show that levels vary from one location to another, depending on the underlying geology. The effect of a lead shield on a gamma radiation field was also…

  9. Regional Background Fine Particulate Matter

    EPA Science Inventory

    A modeling system composed of the global model GEOS-Chem providing hourly lateral boundary conditions to the regional model CMAQ was used to calculate the policy relevant background level of fine particulate: matter. Simulations were performed for the full year of 2004 over the d...

  10. Low background techniques in CANDLES

    SciTech Connect

    Nakajima, K. E-mail: nkyohei@u-fukui.ac.jp; Iida, T.; Matsuoka, K.; Nomachi, M.; Umehara, S.; Kishimoto, T.; Chan, W. M.; Kakubata, H.; Li, X.; Maeda, T.; Ohata, T.; Temuge, B.; Tetsuno, K.; Trang, V. T. T.; Uehara, T.; Yoshida, S.; Morishita, K.; Ogawa, I.; Sakamoto, K.; Tamagawa, Y.; and others

    2015-08-17

    CANDLES is a double beta decay experiment using {sup 48}Ca in CaF{sub 2} crystals. The measurement is being performed with prototype detector (CANDLES III) for high sensitive measurement in the future. Recent status of detector improvements and background reduction techniques are described in this paper.

  11. Teacher Pensions: A Background Paper

    ERIC Educational Resources Information Center

    Hansen, Janet S.

    2008-01-01

    Pensions are an important but comparatively unexamined component of human resource policies in education. In an increasingly competitive world where employees are more mobile than ever, pension policies that were designed in the last century may be out of step with the needs of both individuals and schools. This background paper aims to foster…

  12. Low background techniques in CANDLES

    NASA Astrophysics Data System (ADS)

    Nakajima, K.; Iida, T.; Kishimoto, T.; Matsuoka, K.; Nomachi, M.; Umehara, S.; Chan, W. M.; Kakubata, H.; Li, X.; Maeda, T.; Ohata, T.; Temuge, B.; Tetsuno, K.; Trang, V. T. T.; Uehara, T.; Yoshida, S.; Morishita, K.; Ogawa, I.; Sakamoto, K.; Tamagawa, Y.; Yoshizawa, M.; Fushimi, K.; Hazama, R.; Naktani, N.; Suzuki, K.

    2015-08-01

    CANDLES is a double beta decay experiment using 48Ca in CaF2 crystals. The measurement is being performed with prototype detector (CANDLES III) for high sensitive measurement in the future. Recent status of detector improvements and background reduction techniques are described in this paper.

  13. The cosmic infrared background experiment

    NASA Astrophysics Data System (ADS)

    Bock, James; Battle, John; Cooray, Asantha; Kawada, Mitsunobu; Keating, Brian; Lange, Andrew; Lee, Dae-Hea; Matsumoto, Toshio; Matsuura, Shuji; Pak, Soojong; Renbarger, Tom; Sullivan, Ian; Tsumura, Kohji; Wada, Takehiko; Watabe, Toyoki

    2006-03-01

    The extragalactic background, based on absolute measurements reported by DIRBE and IRTS at 1.2 and 2.2 μm, exceeds the brightness derived from galaxy counts by up to a factor 5. Furthermore, both DIRBE and the IRTS report fluctuations in the near-infrared sky brightness that appear to have an extra-galactic origin, but are larger than expected from local ( z = 1-3) galaxies. These observations have led to speculation that a new class of high-mass stars or mini-quasars may dominate primordial star formation at high-redshift ( z ˜ 10-20), which, in order to explain the excess in the near-infrared background, must be highly luminous but produce a limited amount of metals and X-ray photons. Regardless of the nature of the sources, if a significant component of the near-infrared background comes from first-light galaxies, theoretical models generically predict a prominent near-infrared spectral feature from the redshifted Lyman cutoff, and a distinctive fluctuation power spectrum. We are developing a rocket-borne instrument (the Cosmic Infrared Background ExpeRiment, or CIBER) to search for signatures of primordial galaxy formation in the cosmic near-infrared extra-galactic background. CIBER consists of a wide-field two-color camera, a low-resolution absolute spectrometer, and a high-resolution narrow-band imaging spectrometer. The cameras will search for spatial fluctuations in the background on angular scales from 7″ to 2°, where a first-light galaxy signature is expected to peak, over a range of angular scales poorly covered by previous experiments. CIBER will determine if the fluctuations reported by the IRTS arise from first-light galaxies or have a local origin. In a short rocket flight CIBER has sensitivity to probe fluctuations 100× fainter than IRTS/DIRBE, with sufficient resolution to remove local-galaxy correlations. By jointly observing regions of the sky studied by Spitzer and ASTRO-F, CIBER will build a multi-color view of the near

  14. The Cosmic Infrared Background Experiment

    NASA Astrophysics Data System (ADS)

    Bock, James; Battle, J.; Cooray, A.; Hristov, V.; Kawada, M.; Keating, B.; Lee, D.; Matsumoto, T.; Matsuura, S.; Nam, U.; Renbarger, T.; Sullivan, I.; Tsumura, K.; Wada, T.; Zemcov, M.

    2009-01-01

    We are developing the Cosmic Infrared Background ExpeRiment (CIBER) to search for signatures of first-light galaxy emission in the extragalactic background. The first generation of stars produce characteristic signatures in the near-infrared extragalactic background, including a redshifted Ly-cutoff feature and a characteristic fluctuation power spectrum, that may be detectable with a specialized instrument. CIBER consists of two wide-field cameras to measure the fluctuation power spectrum, and a low-resolution and a narrow-band spectrometer to measure the absolute background. The cameras will search for fluctuations on angular scales from 7 arcseconds to 2 degrees, where the first-light galaxy spatial power spectrum peaks. The cameras have the necessary combination of sensitivity, wide field of view, spatial resolution, and multiple bands to make a definitive measurement. CIBER will determine if the fluctuations reported by Spitzer arise from first-light galaxies. The cameras observe in a single wide field of view, eliminating systematic errors associated with mosaicing. Two bands are chosen to maximize the first-light signal contrast, at 1.6 um near the expected spectral maximum, and at 1.0 um; the combination is a powerful discriminant against fluctuations arising from local sources. We will observe regions of the sky surveyed by Spitzer and Akari. The low-resolution spectrometer will search for the redshifted Lyman cutoff feature in the 0.7 - 1.8 um spectral region. The narrow-band spectrometer will measure the absolute Zodiacal brightness using the scattered 854.2 nm Ca II Fraunhofer line. The spectrometers will test if reports of a diffuse extragalactic background in the 1 - 2 um band continues into the optical, or is caused by an under estimation of the Zodiacal foreground. We report performance of the assembled and tested instrument as we prepare for a first sounding rocket flight in early 2009. CIBER is funded by the NASA/APRA sub-orbital program.

  15. Current sensor

    DOEpatents

    Yakymyshyn, Christopher Paul; Brubaker, Michael Allen; Yakymyshyn, Pamela Jane

    2007-01-16

    A current sensor is described that uses a plurality of magnetic field sensors positioned around a current carrying conductor. The sensor can be hinged to allow clamping to a conductor. The current sensor provides high measurement accuracy for both DC and AC currents, and is substantially immune to the effects of temperature, conductor position, nearby current carrying conductors and aging.

  16. The Cosmic Microwave Background and its Polarization

    NASA Astrophysics Data System (ADS)

    Wollack, Edward

    2017-01-01

    The subtle spatial variations in the cosmic microwave background (CMB) radiation provide a unique astrophysical probe of the early Universe. Characterization of this relic radiation and its polarization have the power to reveal and constrain the properties of light astroparticle species, long wave gravitational radiation, and intervening mass concentrations. Recent advances in theory, observation, and instrumentation have set the stage to experimentally confront the inflationary paradigm via precision polarimetric surveys of the CMB. Current and proposed future observational efforts from the ground, balloon, and spaceborne platforms will be briefly surveyed in this presentation. Recent community activities by the Inflation Probe Science Interest Group (IPSIG) will also be presented.

  17. WFC3/UVIS Sky Backgrounds

    NASA Astrophysics Data System (ADS)

    Baggett, Sylvia; Anderson, Jay

    2012-06-01

    This report summarizes the on-orbit background levels present in WFC3/UVIS full-frame images. The results are based on nearly all standard readout images taken since the installation of WFC3 on HST in May 2009, with a relatively small number of exclusions e.g. images with obvious anomalous backgrounds (such as extended targets filling the field of view) or those taken with the quad filters (different bandpass in each amp). Comparisons are provided to estimates from the Exposure Time Calculator (ETC). We anticipate these results to be helpful in fine-tuning the level of post-flash required to achieve the optimum balance of charge transfter efficiency (CTE) loss mitigation versus noise penalty. Observers considering the use of post-flash should refer to the White Paper (MacKenty & Smith 2012) on the CTE WWW page (http://www.stsci.edu/hst/wfc3/ins_performance/CTE/).

  18. Conductivity in an anisotropic background

    SciTech Connect

    Lee, Bum-Hoon; Nam, Siyoung; Pang, Da-Wei; Park, Chanyong

    2011-03-15

    By using the gauge/gravity duality, we investigate the dual field theories of the anisotropic backgrounds, which are exact solutions of Einstein-Maxwell-dilaton theory with a Liouville potential. When we turn on the bulk gauge field fluctuation A{sub x} with a nontrivial dilaton coupling, the AC conductivity of this dual field theory is proportional to the frequency with an exponent depending on parameters of the anisotropic background. In some parameter regions, we find that this conductivity can have the negative exponent like the strange metal. In addition, we also investigate another U(1) gauge field fluctuation, which is not coupled with a dilaton field. We classify all possible conductivities of this system and find that the exponent of the conductivity is always positive.

  19. Background suppression techniques in germanium detectors

    NASA Technical Reports Server (NTRS)

    Gehrels, Neil; Cheung, Cynthia

    1992-01-01

    A new generation of astrophysical gamma ray spectrometers employing germanium solid state detectors for precise energy measurement are currently being planned for spaceflight in the late 1990's and the early 21st century. Because the observations of weak celestial sources are carried out in an intense radiation environment, the key objective of instrument design is to find ways to reduce the background. The current state of the knowledge in this field is reviewed and the new hardware techniques under design and test are discussed. Many of these techniques have already been flight tested on balloon platforms. Recent results from some of these tests are presented. By carefully applying these techniques it should be possible to achieve sensitivities that are factors of 3 to 10 better than would be obtained for a conventional instrument of similar weight.

  20. Cosmic Microwave Background Polarization and Inflation

    NASA Technical Reports Server (NTRS)

    Chuss, David T.

    2011-01-01

    Measurements of the cosmic microwave background (CMB) offer a means to explore the universe at a very early epoch. Specifically, if the universe went through a brief period of exponential expansion called inflation as current data suggest, gravitational waves from this period would polarize the CMB in a specific pattern. At GSFC, we are currently working towards two experiments that work in concert to measure this polarization pattern in search of evidence for inflation. The Cosmology Large Angular Scale Surveyor (CLASS) will measure the polarization at frequencies between 40 and 150 GHz from the Atacama Desert in Chile. The Primordial Inflation Polarization Explorer (PIPER) is a balloon-borne experiment that will make similar measurements at frequencies between 200 and 600 GHz.

  1. The Cosmic Background Explorer /COBE/

    NASA Technical Reports Server (NTRS)

    Mather, J. C.

    1982-01-01

    The Cosmic Background Explorer (COBE) satellite, under study by NASA since 1976, will map the spectrum and the angular distribution of diffuse radiation from the universe over the entire wavelength range from 1 micron to 1.3 cm. It carries three instruments: a set of differential microwave radiometers (DMR) at 23.5, 31.4, 53, and 90GHz, a far infrared absolute spectrophotometer (FIRAS) covering 1 to 100 per cm, and a diffuse infrared background experiment (DIRBE) covering 1 to 300 microns. They will use the ideal space environment, a one year lifetime, and standard instrument techniques to achieve orders of magnitude improvements in sensitivity and accuracy, providing a fundamental data base for cosmology. The instruments are united by common purpose as well as similar environmental and orbital requirements. The data from all three experiments will be analyzed together, to distinguish nearby sources of radiation from the cosmologically interesting diffuse background radiations. Construction is planned to begin in 1982 for a launch in 1988.

  2. Background independence in a background dependent renormalization group

    NASA Astrophysics Data System (ADS)

    Labus, Peter; Morris, Tim R.; Slade, Zöe H.

    2016-07-01

    Within the derivative expansion of conformally reduced gravity, the modified split Ward identities are shown to be compatible with the flow equations if and only if either the anomalous dimension vanishes or the cutoff profile is chosen to have a power-law form. No solutions exist if the Ward identities are incompatible. In the compatible case, a clear reason is found for why Ward identities can still forbid the existence of fixed points; however, for any cutoff profile, a background independent (and parametrization independent) flow equation is uncovered. Finally, expanding in vertices, the combined equations are shown generically to become either overconstrained or highly redundant beyond the six-point level.

  3. Robustness of cosmic neutrino background detection in the cosmic microwave background

    SciTech Connect

    Audren, Benjamin; Bellini, Emilio; Cuesta, Antonio J.; Verde, Licia; Gontcho, Satya Gontcho A; Pérez-Ràfols, Ignasi; Lesgourgues, Julien; Niro, Viviana; Tram, Thomas

    2015-03-01

    The existence of a cosmic neutrino background can be probed indirectly by CMB experiments, not only by measuring the background density of radiation in the universe, but also by searching for the typical signatures of the fluctuations of free-streaming species in the temperature and polarisation power spectrum. Previous studies have already proposed a rather generic parametrisation of these fluctuations, that could help to discriminate between the signature of ordinary free-streaming neutrinos, or of more exotic dark radiation models. Current data are compatible with standard values of these parameters, which seems to bring further evidence for the existence of a cosmic neutrino background. In this work, we investigate the robustness of this conclusion under various assumptions. We generalise the definition of an effective sound speed and viscosity speed to the case of massive neutrinos or other dark radiation components experiencing a non-relativistic transition. We show that current bounds on these effective parameters do not vary significantly when considering an arbitrary value of the particle mass, or extended cosmological models with a free effective neutrino number, dynamical dark energy or a running of the primordial spectrum tilt. We conclude that it is possible to make a robust statement about the detection of the cosmic neutrino background by CMB experiments.

  4. Radon background study in Super-Kamiokande

    NASA Astrophysics Data System (ADS)

    Nakano, Yuuki; Super-Kamiokande Collaboration

    2017-09-01

    Super-Kamiokande (SK), a 50 kton water Cherenkov detector in Japan, observes 8B solar neutrinos with neutrino-electron elastic scattering. SK searches for distortions of the solar neutrino energy spectrum caused by the edge of the MSW resonance in the core of the Sun. The installation of new front-end electronics in 2008 marks the beginning of the 4th phase of SK (SK-IV). With the improvement of the water circulation system, calibration methods, reduction cuts, this phase achieved the lowest energy threshold thus far (3.5 MeV kinetic energy). To improve the sensitivity to the MSW effect, it is required to achieve lower energy threshold. For this purpose, understanding the origin of background events and reducing them are important. Currently, the main background is known as a beta decay of 214Bi in a Radon decay chain. So far, SK collaboration has developed several techniques for studying Radon contamination in the SK water. In this proceedings, a measurement system which can measure Radon concentration in the SK water with the accuracy of 0.1 mBq/m3 level is presented. In addition, an evaluation of Radon background events in SK injecting Radon rich water into the SK tank, as well as future prospects are also presented.

  5. Low-Background Counting at Homestake

    NASA Astrophysics Data System (ADS)

    Marshall, Iseley

    2009-10-01

    Background characterization at Homestake is an ongoing project crucial to the experiments located there. From neutrino physics to WIMP detection, low-background materials and their screening require highly sensitive detectors. Naturally, shielding is needed to lower ``noise'' in these detectors. Because of its vast depth, Homestake will be effective in shielding against cosmic-ray radiation. This means little, however, if radiation from materials used still interferes. Specifically, our group is working on designing the first low-background counting facility at the Homestake mine. Using a high-purity germanium crystal detector from ORTEC, measurements will be taken within a shield that is made to specifically account for radiation underground and fits the detector. Currently, in the design, there is a layer of copper surrounded by an intricate stainless steel casing, which will be manufactured air tight to accommodate for nitrogen purging. Lead will surround the stainless steel shell to further absorb gamma rays. A mobile lift system has been designed for easy access to the detector. In the future, this project will include multiple testing stations located in the famous Davis Cavern where future experiments will have the ability to use the site as an efficient and accurate counting facility for their needs (such as measuring radioactive isotopes in materials). Overall, this detector (and its shield system) is the beginning of a central testing facility that will serve Homestake's scientific community.

  6. Limits of Astrophysics with Gravitational-Wave Backgrounds

    NASA Astrophysics Data System (ADS)

    Callister, Thomas; Sammut, Letizia; Qiu, Shi; Mandel, Ilya; Thrane, Eric

    2016-07-01

    The recent Advanced LIGO detection of gravitational waves from the binary black hole GW150914 suggests there exists a large population of merging binary black holes in the Universe. Although most are too distant to be individually resolved by advanced detectors, the superposition of gravitational waves from many unresolvable binaries is expected to create an astrophysical stochastic background. Recent results from the LIGO and Virgo Collaborations show that this astrophysical background is within reach of Advanced LIGO. In principle, the binary black hole background encodes interesting astrophysical properties, such as the mass distribution and redshift distribution of distant binaries. However, we show that this information will be difficult to extract with the current configuration of advanced detectors (and using current data analysis tools). Additionally, the binary black hole background also constitutes a foreground that limits the ability of advanced detectors to observe other interesting stochastic background signals, for example, from cosmic strings or phase transitions in the early Universe. We quantify this effect.

  7. Particle production in a gravitational wave background

    NASA Astrophysics Data System (ADS)

    Jones, Preston; McDougall, Patrick; Singleton, Douglas

    2017-03-01

    We study the possibility that massless particles, such as photons, are produced by a gravitational wave. That such a process should occur is implied by tree-level Feynman diagrams such as two gravitons turning into two photons, i.e., g +g →γ +γ . Here we calculate the rate at which a gravitational wave creates a massless scalar field. This is done by placing the scalar field in the background of a plane gravitational wave and calculating the 4-current of the scalar field. Even in the vacuum limit of the scalar field it has a nonzero vacuum expectation value (similar to what occurs in the Higgs mechanism) and a nonzero current. We associate this with the production of scalar field quanta by the gravitational field. This effect has potential consequences for the attenuation of gravitational waves since the massless field is being produced at the expense of the gravitational field. This is related to the time-dependent Schwinger effect, but with the electric field replaced by the gravitational wave background and the electron/positron field quanta replaced by massless scalar "photons." Since the produced scalar quanta are massless there is no exponential suppression, as occurs in the Schwinger effect due to the electron mass.

  8. The Sunyaev-Zeldovich background

    NASA Astrophysics Data System (ADS)

    Holder, Gilbert P.; McCarthy, Ian G.; Babul, A.

    2007-12-01

    The cosmic background due to the Sunyaev-Zeldovich (SZ) effect is expected to be the largest signal at mm and cm wavelengths at a resolution of a few arcminutes. We investigate some simple statistics of SZ maps and their scaling with the normalization of the matter power spectrum, σ8, as well as the effects of the unknown physics of the intracluster medium on these statistics. We show that the SZ background provides a significant background for SZ cluster searches, with the onset of confusion occurring around 1014h-1Msolar in a cosmology-dependent way, where confusion is defined as typical errors in recovered flux larger than 20 per cent. The confusion limit corresponds to the mass at which there are roughly 10 clusters per square degree, with this number nearly independent of cosmology and cluster gas physics. Typical errors grow quickly as lower mass objects are included in the catalogue. We also point out that there is nothing in particular about the rms of the filtered map that makes it especially well suited for capturing aspects of the SZ effect, and other indicators of the one-point SZ probability distribution function are at least as well suited for the task. For example, the full width at half-maximum of the one-point probability distribution has a field-to-field scatter that is about 60 per cent that of the rms. The simplest statistics of SZ maps are largely unaffected by cluster physics such as preheating, although the impact of preheating is clear by eye in the maps. Studies aimed at learning about the physics of the intracluster medium will apparently require more specialized statistical indicators.

  9. Teaching about natural background radiation

    NASA Astrophysics Data System (ADS)

    Al-Azmi, Darwish; Karunakara, N.; Mustapha, Amidu O.

    2013-07-01

    Ambient gamma dose rates in air were measured at different locations (indoors and outdoors) to demonstrate the ubiquitous nature of natural background radiation in the environment and to show that levels vary from one location to another, depending on the underlying geology. The effect of a lead shield on a gamma radiation field was also demonstrated to emphasize the important role of shielding in radiation protection. The measurements were carried out with a Geiger-Muller (GM)-based dosimeter and a NaI scintillation gamma-ray spectrometer, which are normally available in physics laboratories. Radioactivity in household materials was demonstrated using a gas mantle as an example.

  10. The Cosmic Background Explorer Satellite

    NASA Technical Reports Server (NTRS)

    Mather, J.; Kelsall, T.

    1980-01-01

    The Cosmic Background Explorer (COBE) satellite, planned for launch in 1985, will measure the diffuse infrared and microwave radiation of the universe over the entire wavelength range from a few microns to 1.3 cm. It will include three instruments: a set of microwave isotropy radiometers at 23, 31, 53, and 90 GHz, an interferometer spectrometer from 1 to 100/cm, and a filter photometer from 1 to 300 microns. The COBE satellite is designed to reach the sensitivity limits set by foreground sources such as the interstellar and interplanetary dust, starlight, and galactic synchrotron radiation, so that a diffuse residual radiation may be interpreted unambiguously as extragalactic

  11. Saliency detection via background invariance in scale space

    NASA Astrophysics Data System (ADS)

    Zhou, Li; Ju, Yongfeng; Fang, Jianwu; Xue, Jianru

    2017-07-01

    Background prior selection is the key step in current ranking-based saliency detection approaches. The existing related methods usually choose boundary regions of an image or the region with low initial saliency value in single image scale as the background. Then, the saliency map is obtained by ranking the inside similarity and correlation. However, these methods cannot handle situations in which the salient object lies on the image boundary (boundary-salient) multiple salient objects exist in a single image (multisalient). To this end, this paper proposes an adaptive background selection method by exploiting the background invariance in different image scales within distinct color spaces. Through embedding the selected background prior into multiple newly proposed ranking-based saliency methods, the superiority of the obtained background prior is strongly verified. Exhaustive experiments on four challenging datasets demonstrate that the proposed method outperforms the state-of-the-art methods in handling the boundary-salient and multisalient situations.

  12. [Cosmic Microwave Background (CMB) Anisotropies

    NASA Technical Reports Server (NTRS)

    Silk, Joseph

    1998-01-01

    One of the main areas of research is the theory of cosmic microwave background (CMB) anisotropies and analysis of CMB data. Using the four year COBE data we were able to improve existing constraints on global shear and vorticity. We found that, in the flat case (which allows for greatest anisotropy), (omega/H)0 less than 10(exp -7), where omega is the vorticity and H is the Hubble constant. This is two orders of magnitude lower than the tightest, previous constraint. We have defined a new set of statistics which quantify the amount of non-Gaussianity in small field cosmic microwave background maps. By looking at the distribution of power around rings in Fourier space, and at the correlations between adjacent rings, one can identify non-Gaussian features which are masked by large scale Gaussian fluctuations. This may be particularly useful for identifying unresolved localized sources and line-like discontinuities. Levin and collaborators devised a method to determine the global geometry of the universe through observations of patterns in the hot and cold spots of the CMB. We have derived properties of the peaks (maxima) of the CMB anisotropies expected in flat and open CDM models. We represent results for angular resolutions ranging from 5 arcmin to 20 arcmin (antenna FWHM), scales that are relevant for the MAP and COBRA/SAMBA space missions and the ground-based interferometer. Results related to galaxy formation and evolution are also discussed.

  13. Video coding with dynamic background

    NASA Astrophysics Data System (ADS)

    Paul, Manoranjan; Lin, Weisi; Lau, Chiew Tong; Lee, Bu-Sung

    2013-12-01

    Motion estimation (ME) and motion compensation (MC) using variable block size, sub-pixel search, and multiple reference frames (MRFs) are the major reasons for improved coding performance of the H.264 video coding standard over other contemporary coding standards. The concept of MRFs is suitable for repetitive motion, uncovered background, non-integer pixel displacement, lighting change, etc. The requirement of index codes of the reference frames, computational time in ME & MC, and memory buffer for coded frames limits the number of reference frames used in practical applications. In typical video sequences, the previous frame is used as a reference frame with 68-92% of cases. In this article, we propose a new video coding method using a reference frame [i.e., the most common frame in scene (McFIS)] generated by dynamic background modeling. McFIS is more effective in terms of rate-distortion and computational time performance compared to the MRFs techniques. It has also inherent capability of scene change detection (SCD) for adaptive group of picture (GOP) size determination. As a result, we integrate SCD (for GOP determination) with reference frame generation. The experimental results show that the proposed coding scheme outperforms the H.264 video coding with five reference frames and the two relevant state-of-the-art algorithms by 0.5-2.0 dB with less computational time.

  14. Focal plane infrared readout circuit with automatic background suppression

    NASA Technical Reports Server (NTRS)

    Pain, Bedabrata (Inventor); Yang, Guang (Inventor); Sun, Chao (Inventor); Shaw, Timothy J. (Inventor); Wrigley, Chris J. (Inventor)

    2002-01-01

    A circuit for reading out a signal from an infrared detector includes a current-mode background-signal subtracting circuit having a current memory which can be enabled to sample and store a dark level signal from the infrared detector during a calibration phase. The signal stored by the current memory is subtracted from a signal received from the infrared detector during an imaging phase. The circuit also includes a buffered direct injection input circuit and a differential voltage readout section. By performing most of the background signal estimation and subtraction in a current mode, a low gain can be provided by the buffered direct injection input circuit to keep the gain of the background signal relatively small, while a higher gain is provided by the differential voltage readout circuit. An array of such readout circuits can be used in an imager having an array of infrared detectors. The readout circuits can provide a high effective handling capacity.

  15. Contract Education: A Background Paper.

    ERIC Educational Resources Information Center

    California Community Colleges, Sacramento. Academic Senate.

    Today contract education is generally thought of as a program or course for which an employer is paying the full cost of instruction for customized training. Contract education can help faculty remain current, encourage industry to make equipment available to the college that might otherwise be too expensive, and provide employment opportunities…

  16. Texture induced microwave background anisotropies

    SciTech Connect

    Borrill, Julian; Copeland, Edmund J.; Liddle, Andrew R.; Stebbins, Albert; Veeraraghavan, Shoba

    1994-03-01

    We use numerical simulations to calculate the cosmic microwave background anisotropy induced by the evolution of a global texture field, with special emphasis on individual textures. Both spherically symmetric and general configurations are analyzed, and in the latter case we consider field configurations which exhibit unwinding events and also ones which do not. We compare the results given by evolving the field numerically under both the expanded core (XCORE) and non-linear sigma model (NLSM) approximations with the analytic predictions of the NLSM exact solution for a spherically symmetric self-similar (SSSS) unwinding. We find that the random unwinding configuration spots' typical peak height is 60-75\\% and angular size typically only 10% of those of the SSSS unwinding, and that random configurations without an unwinding event nonetheless may generate indistinguishable hot and cold spots. A brief comparison is made with other work.

  17. Background illumination and automated perimetry.

    PubMed

    Klewin, K M; Radius, R L

    1986-03-01

    Visual field function in the right and left eyes of 31 normal volunteers was evaluated with an automated projection perimeter (OCTOPUS). Serial visual field evaluations were repeated in these same eyes with neutral filters of increasing optical density. We compared the results of threshold determinations with the different neutral filters in place before the examined eye. Significant reduction in threshold sensitivity at several test spots throughout the central 30 degrees visual field was seen with neutral density filters of 0.5 log units or greater. The low level of background illumination of the OCTOPUS perimeter (4.0 apostilbs) may allow relatively minor reduction in light transmission by the ocular media to produce significant changes in the recorded level of threshold sensitivity during visual field evaluation.

  18. Compressive Sensing for Background Subtraction

    DTIC Science & Technology

    2009-12-20

    i) reconstructing an image using only a single optical pho- todiode (infrared, hyperspectral, etc.) along with a digital micromirror device ( DMD ...robust against packet drops. The SPC architecture uses a DMD to generate a random sampling pattern and sends the resulting inner product of the incident...a set of M consecutive measurements can be made about the scene using the same optical sensor, which form the measurement vector y. The current DMD

  19. Low Background Assay Results for LZ

    NASA Astrophysics Data System (ADS)

    Oliver-Mallory, Kelsey; Thomas, Keenan; Lux-Zeplin Collaboration; Berkeley Low Background Facility Team

    2016-03-01

    The next generation dark matter experiment LUX-ZEPLIN (LZ) requires careful control of intrinsic radioactivity in all critical detector components in order to reach its unprecedented target sensitivity to Weakly Interacting Massive Particles (WIMPs): 2 ×10-48 cm2 at 50 GeV/c2. Appropriate material selection is essential to meeting this goal, and an extensive campaign of low background screening is currently being carried out using assay devices at the Sanford Underground Research Facility and the Boulby Underground Laboratory. We will present results from this work, including measurements for the Ti cryostat, PMT bases, PMT raw materials, PTFE, and other components. This work was partially supported by the U.S. Department of Energy (DOE) under Award Number DE-AC02-05CH11231, and is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. 1106400.

  20. Resolving the Extragalactic Gamma-ray Background

    NASA Astrophysics Data System (ADS)

    Ajello, Marco; Di Mauro, Mattia; Manconi, Silvia; Zechlin, Hannes

    2017-08-01

    Models of the extragalactic gamma-ray background (EGB) show that its intensity can be ascribed to the integrated emission of source populations, like blazars, already detected by the Fermi Large Area Telescope (LAT). Taking advantage of the sensitivity increase delivered by Pass 8, the newest event-level analysis, we tested this hypothesis employing a photon fluctuation analysis above 50 GeV. For the first time we were able to resolve nearly the entire EGB and show that blazars contribute at least 85% of the EGB intensity. We will discuss how this analysis can be extended to lower energies and present our current understanding of the origin of the EGB, its ties to the neutrino flux measured by IceCube and the capability to constrain scenarios of dark matter interaction.

  1. Detection prospects of the cosmic neutrino background

    NASA Astrophysics Data System (ADS)

    Li, Yu-Feng

    2015-04-01

    The existence of the cosmic neutrino background (CνB) is a fundamental prediction of the standard Big Bang cosmology. Although current cosmological probes provide indirect observational evidence, the direct detection of the CνB in a laboratory experiment is a great challenge to the present experimental techniques. We discuss the future prospects for the direct detection of the CνB, with the emphasis on the method of captures on beta-decaying nuclei and the PTOLEMY project. Other possibilities using the electron-capture (EC) decaying nuclei, the annihilation of extremely high-energy cosmic neutrinos (EHECνs) at the Z-resonance, and the atomic de-excitation method are also discussed in this review (talk given at the International Conference on Massive Neutrinos, Singapore, 9-13 February 2015).

  2. Detection Prospects of the Cosmic Neutrino Background

    NASA Astrophysics Data System (ADS)

    Li, Yu-Feng

    The existence of the cosmic neutrino background (CνB) is a fundamental prediction of the standard Big Bang cosmology. Although current cosmological probes provide indirect observational evidence, the direct detection of the CνB in a laboratory experiment is a great challenge to the present experimental techniques. We discuss the future prospects for the direct detection of the CνB, with the emphasis on the method of captures on beta-decaying nuclei and the PTOLEMY project. Other possibilities using the electron-capture (EC) decaying nuclei, the annihilation of extremely high-energy cosmic neutrinos (EHECνs) at the Z-resonance, and the atomic de-excitation method are also discussed in this review.

  3. FLUKA: Predictive power for cosmogenic backgrounds

    SciTech Connect

    Empl, A. Hungerford, E. V.; Ferrari, A.; Smirnov, G. I.

    2015-08-17

    The next generation of experiments searching for rare physics events with increased sensitivity will require precise predictions of cosmogenic backgrounds. Recent high quality deep underground measurements for cosmogenic neutrons in large liquid scintillator targets were used to study the FLUKA simulation package for this purpose. The results and conclusions drawn from a detailed benchmark comparison with data from the Borexino experiment were reported recently. In general, good agreement between data and simulation results were found with some identified discrepancies. Improved physics models already implemented in the current version of the FLUKA code, which will be publicly available with the upcoming code release, address the more important identified issues. A careful evaluation of the improved predictions is ongoing. However, the agreement between preliminary FLUKA simulation results and the Borexino experimental data are excellent. The preliminary findings will be discussed.

  4. The Beta Cage: Screening Low Radioactive Backgrounds

    NASA Astrophysics Data System (ADS)

    Poinar, K.; Akerib, D.; Grant, D.; Schnee, R.; Shutt, T.; Golwala, S.; Ahmed, Z.

    2006-10-01

    The beta cage is a proposed multi-wire proportional chamber that will be the most sensitive device available to screen low-energy (200 keV) betas emitted at rates as low as 10-5 counts keV^1 cm-2 day-1 (of order 10-4 Bq/m^2). The expected sensitivity and details of the construction and commissioning of its prototype chamber are presented. The prototype beta cage is a 50x50x25 cm frame gridded by stacked wire planes contained in a chamber of gas. To reduce background, the chamber contains only enough mass to stop betas of interest. Samples are placed beneath the grid; the wires multiply the betas and collect their electron avalanche. Readouts allow discrimination of its events from background and determination of the beta (or alpha) source. The beta cage has potential use in carbon or tritium dating, with ^3H/^1H sensitivity of 10-20 and ^ 14C/ ^12C sensitivity of 10-18. Its design was motivated by CDMS, whose sensitivity to the dark matter candidate WIMPs is currently limited by low-energy beta contamination.

  5. New window into stochastic gravitational wave background.

    PubMed

    Rotti, Aditya; Souradeep, Tarun

    2012-11-30

    A stochastic gravitational wave background (SGWB) would gravitationally lens the cosmic microwave background (CMB) photons. We correct the results provided in existing literature for modifications to the CMB polarization power spectra due to lensing by gravitational waves. Weak lensing by gravitational waves distorts all four CMB power spectra; however, its effect is most striking in the mixing of power between the E mode and B mode of CMB polarization. This suggests the possibility of using measurements of the CMB angular power spectra to constrain the energy density (Ω(GW)) of the SGWB. Using current data sets (QUAD, WMAP, and ACT), we find that the most stringent constraints on the present Ω(GW) come from measurements of the angular power spectra of CMB temperature anisotropies. In the near future, more stringent bounds on Ω(GW) can be expected with improved upper limits on the B modes of CMB polarization. Any detection of B modes of CMB polarization above the expected signal from large scale structure lensing could be a signal for a SGWB.

  6. Acid rain: a background report

    SciTech Connect

    Glustrom, L.; Stolzenberg, J.

    1982-07-08

    This Staff Brief was prepared for the Wisconsin Legislative Council's Special Committee on Acid Rain to provide an introduction to the issue of acid rain. It is divided into four parts. Part I provides an overview on the controversies surrounding the measurement, formation and effects of acid rain. As described in Part I, the term acid rain is used to describe the deposition of acidic components through both wet deposition (e.g., rain or snow) and dry deposition (e.g., direct contact between atmospheric constituents and the land, water or vegetation of the earth). Part II presents background information on state agency activities relating to acid rain in Wisconsin, describes what is known about the occurrence of, susceptibility to and effects of acid rain in Wisconsin, and provides information related to man-made sources of sulfur and nitrogen oxides in Wisconsin. Part III describes major policies and regulations relating to acid rain which have been or are being developed jointly by the United States and Canadian governments, by the United States government and by the State of Wisconsin. Part IV briefly discusses possible areas for Committee action.

  7. The Diffuse Extreme Ultraviolet Background

    NASA Technical Reports Server (NTRS)

    Vallerga, John; Slavin, Jonathan

    1996-01-01

    Observations of the diffuse EUV background towards 138 different directions using the spectrometers aboard the Extreme Ultraviolet Explorer satellite (EUVE) have been combined into a spectrum from 150A to 730A and represent an effective exposure of 18 million seconds. There is no significant evidence of any non-local line flux in the resultant spectrum such as that from a hot coronal plasma. These results are inconsistent with the Wisconsin C and B broad-band surveys assuming the source is a logT = 5.8 - 6.1 hot plasma in ionization equilibrium with solar abundances, confirming the previous result of Jelinksy, Vallerga and Edelstein) (hereafter Paper 1) using an observation along the ecliptic with the same instrument. To make these results consistent with the previous broad-band surveys, the plasma responsible for the emission must either be depleted in Fe by a factor of approximately 6, be behind an absorbing slab of neutral H with a column of 2 x 10(exp 19)/sq cm, or not be in collisional ionization equilibrium (CIE). One such non-CIE model (Breitswerdt and Schmutzier) that explains the soft x-ray results is also inconsistent with this EUV data.

  8. Background modelling in Rietveld analysis

    SciTech Connect

    Richardson, J.W. Jr.

    1989-12-31

    The Rietveld method is a complete profile fitting technique, which requires modelling the total scattering from crystalline samples. Many diffraction experiments involve the analysis of scattering patterns containing additional noncrystalline scattering components; these components are broad oscillations superimposed on the sharp Bragg pattern. Conventional background functions cannot be used for the noncrystalline scattering; but treating the additional scattering as though it were from an amorphous material can provide additional structural information. This is demonstrated using AlPO{sub 4}-5, an aluminophosphate framework molecular sieve. The correlation function for the amorphous component has peaks close to interatomic distances also characteristic of the crystal. The cose agreement suggests that the amorphous component, although lacking long-range periodicity, has a similar atomic arrangement to the crystal. A calibration experiment is performed using a 50-50 wt% quartz-amorphous silica mixture; the crystal structural parameters obtained from Fourier-filtered data are compared with neutron powder diffraction refinement of quartz and single-crystal x-ray results. All refined parameters agree within 3-4 {sigma}. 2 tables, 5 refs, 6 figs. (DLC)

  9. Plenoptic background oriented schlieren imaging

    NASA Astrophysics Data System (ADS)

    Klemkowsky, Jenna N.; Fahringer, Timothy W.; Clifford, Christopher J.; Bathel, Brett F.; Thurow, Brian S.

    2017-09-01

    The combination of the background oriented schlieren (BOS) technique with the unique imaging capabilities of a plenoptic camera, termed plenoptic BOS, is introduced as a new addition to the family of schlieren techniques. Compared to conventional single camera BOS, plenoptic BOS is capable of sampling multiple lines-of-sight simultaneously. Displacements from each line-of-sight are collectively used to build a four-dimensional displacement field, which is a vector function structured similarly to the original light field captured in a raw plenoptic image. The displacement field is used to render focused BOS images, which qualitatively are narrow depth of field slices of the density gradient field. Unlike focused schlieren methods that require manually changing the focal plane during data collection, plenoptic BOS synthetically changes the focal plane position during post-processing, such that all focal planes are captured in a single snapshot. Through two different experiments, this work demonstrates that plenoptic BOS is capable of isolating narrow depth of field features, qualitatively inferring depth, and quantitatively estimating the location of disturbances in 3D space. Such results motivate future work to transition this single-camera technique towards quantitative reconstructions of 3D density fields.

  10. Neurobiological background of negative symptoms.

    PubMed

    Galderisi, Silvana; Merlotti, Eleonora; Mucci, Armida

    2015-10-01

    Studies investigating neurobiological bases of negative symptoms of schizophrenia failed to provide consistent findings, possibly due to the heterogeneity of this psychopathological construct. We tried to review the findings published to date investigating neurobiological abnormalities after reducing the heterogeneity of the negative symptoms construct. The literature in electronic databases as well as citations and major articles are reviewed with respect to the phenomenology, pathology, genetics and neurobiology of schizophrenia. We searched PubMed with the keywords "negative symptoms," "deficit schizophrenia," "persistent negative symptoms," "neurotransmissions," "neuroimaging" and "genetic." Additional articles were identified by manually checking the reference lists of the relevant publications. Publications in English were considered, and unpublished studies, conference abstracts and poster presentations were not included. Structural and functional imaging studies addressed the issue of neurobiological background of negative symptoms from several perspectives (considering them as a unitary construct, focusing on primary and/or persistent negative symptoms and, more recently, clustering them into factors), but produced discrepant findings. The examined studies provided evidence suggesting that even primary and persistent negative symptoms include different psychopathological constructs, probably reflecting the dysfunction of different neurobiological substrates. Furthermore, they suggest that complex alterations in multiple neurotransmitter systems and genetic variants might influence the expression of negative symptoms in schizophrenia. On the whole, the reviewed findings, representing the distillation of a large body of disparate data, suggest that further deconstruction of negative symptomatology into more elementary components is needed to gain insight into underlying neurobiological mechanisms.

  11. Technology Development for Cosmic Microwave Background Cosmology

    NASA Astrophysics Data System (ADS)

    Munson, Charles D.

    2017-05-01

    The Cosmic Microwave Background (CMB) offers a unique window into the early universe by probing thermal radiation remaining from the big bang. Due to its low temperature and bright foregrounds, its thorough characterization requires technological advancement beyond the current state-of-the-art. In this thesis, I present the development and fabrication of novel metamaterial silicon optics to improve the sensitivity of current and future CMB telescopes. By machining subwavelength features into the silicon surfaces, traditional antireflection coatings can be replaced by all-silicon metamaterials that significantly reduce reflections over previous approaches. I discuss the design of these structured surfaces and the design and construction of a sophisticated fabrication facility necessary to implement this technology on large diameter (30+ cm) lenses for the Atacama Cosmology Telescope Polarization project (ACTPol). I then apply this metamaterial technology to the development of improved free-space filters for millimeter and sub-millimeter wavelength imaging (focusing specifically on blocking infrared radiation, necessary for current cryogenic detector systems). This produces a highly effective infrared-blocking filter, blocking over 99% of the incident power from a 300 K blackbody while maintaining transmission of better than 99% in a target CMB observing band (between 70 and 170 GHz). I conclude with a discussion of the development of a real-space simulation framework to assist in better understanding current CMB results and forecasting for future experiments. By taking a CMB realization and adding to it accurate real-space modeling of the Sunyaev-Zel'dovich effect and weak lensing distortions (introduced by galaxy clusters), a better understanding of the impacts of large scale structure on the CMB can be obtained.

  12. Technology Development for Cosmic Microwave Background Cosmology

    NASA Astrophysics Data System (ADS)

    Munson, Charles D.

    The Cosmic Microwave Background (CMB) offers a unique window into the early universe by probing thermal radiation remaining from the big bang. Due to its low temperature and bright foregrounds, its thorough characterization requires technological advancement beyond the current state-of-the-art. In this thesis, I present the development and fabrication of novel metamaterial silicon optics to improve the sensitivity of current and future CMB telescopes. By machining subwavelength features into the silicon surfaces, traditional antireflection coatings can be replaced by all-silicon metamaterials that significantly reduce reflections over previous approaches. I discuss the design of these structured surfaces and the design and construction of a sophisticated fabrication facility necessary to implement this technology on large diameter (30+ cm) lenses for the Atacama Cosmology Telescope Polarization project (ACTPol). I then apply this metamaterial technology to the development of improved free-space filters for millimeter and sub-millimeter wavelength imaging (focusing specifically on blocking infrared radiation, necessary for current cryogenic detector systems). This produces a highly effective infrared-blocking filter, blocking over 99% of the incident power from a 300 K blackbody while maintaining transmission of better than 99% in a target CMB observing band (between 70 and 170 GHz). I conclude with a discussion of the development of a real-space simulation framework to assist in better understanding current CMB results and forecasting for future experiments. By taking a CMB realization and adding to it accurate real-space modeling of the Sunyaev-Zel'dovich effect and weak lensing distortions (introduced by galaxy clusters), a better understanding of the impacts of large scale structure on the CMB can be obtained.

  13. Radon-related Backgrounds in the LUX Dark Matter Search

    NASA Astrophysics Data System (ADS)

    Bradley, A.; Akerib, D. S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Bernard, E.; Bernstein, A.; Byram, D.; Cahn, S. B.; Carmona-Benitez, M. C.; Chan, C.; Chapman, J. J.; Chiller, A. A.; Chiller, C.; Coffey, T.; Currie, A.; de Viveiros, L.; Dobi, A.; Dobson, J.; Druszkiewicz, E.; Edwards, B.; Faham, C. H.; Fiorucci, S.; Flores, C.; Gaitskell, R. J.; Gehman, V. M.; Ghag, C.; Gibson, K. R.; Gilchriese, M. G. D.; Hall, C.; Hertel, S. A.; Horn, M.; Huang, D. Q.; Ihm, M.; Jacobsen, R. G.; Kazkaz, K.; Knoche, R.; Larsen, N. A.; Lee, C.; Lindote, A.; Lopes, M. I.; Malling, D. C.; Mannino, R.; McKinsey, D. N.; Mei, D.-M.; Mock, J.; Moongweluwan, M.; Morad, J.; Murphy, A. St. J.; Nehrkorn, C.; Nelson, H.; Neves, F.; Ott, R. A.; Pangilinan, M.; Parker, P. D.; Pease, E. K.; Pech, K.; Phelps, P.; Reichhart, L.; Shutt, T.; Silva, C.; Solovov, V. N.; Sorensen, P.; O'Sullivan, K.; Sumner, T. J.; Szydagis, M.; Taylor, D.; Tennyson, B.; Tiedt, D. R.; Tripathi, M.; Uvarov, S.; Verbus, J. R.; Walsh, N.; Webb, R.; White, J. T.; Witherell, M. S.; Wolfs, F. L. H.; Woods, M.; Zhang, C.

    The LUX detector is currently in operation at the Davis Campus at the 4850' level of the Sanford Underground Research Facility (SURF) in Lead, SD to directly search for WIMP dark matter. Knowing the type and rate of backgrounds is critical in a rare, low energy event search, and LUX was designed, constructed, and deployed to mitigate backgrounds, both internal and external. An important internal background are decays of radon and its daughters. These consist of alpha decays, which are easily tagged and are a tracer of certain backgrounds, and beta decays, some of which are not as readily tagged and present a background for the WIMP search. We report on studies of alpha decay and discuss implications for the WIMP search.

  14. Radon-related backgrounds in the LUX dark matter search

    DOE PAGES

    Bradley, A.; Akerib, D. S.; Araújo, H. M.; ...

    2015-01-01

    The LUX detector is currently in operation at the Davis Campus at the 4850’ level of the Sanford Underground Research Facility (SURF) in Lead, SD to directly search for WIMP dark matter. Knowing the type and rate of backgrounds is critical in a rare, low energy event search, and LUX was designed, constructed, and deployed to mitigate backgrounds, both internal and external. An important internal background are decays of radon and its daughters. These consist of alpha decays, which are easily tagged and are a tracer of certain backgrounds, and beta decays, some of which are not as readily taggedmore » and present a background for the WIMP search. We report on studies of alpha decay and discuss implications for the WIMP search.« less

  15. Radon-related backgrounds in the LUX dark matter search

    SciTech Connect

    Bradley, A.; Akerib, D. S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Bernard, E.; Bernstein, A.; Byram, D.; Cahn, S. B.; Carmona-Benitez, M. C.; Chan, C.; Chapman, J. J.; Chiller, A. A.; Chiller, C.; Coffey, T.; Currie, A.; de Viveiros, L.; Dobi, A.; Dobson, J.; Druszkiewicz, E.; Edwards, B.; Faham, C. H.; Fiorucci, S.; Flores, C.; Gaitskell, R. J.; Gehman, V. M.; Ghag, C.; Gibson, K. R.; Gilchriese, M. G.D.; Hall, C.; Hertel, S. A.; Horn, M.; Huang, D. Q.; Ihm, M.; Jacobsen, R. G.; Kazkaz, K.; Knoche, R.; Larsen, N. A.; Lee, C.; Lindote, A.; Lopes, M. I.; Malling, D. C.; Mannino, R.; McKinsey, D. N.; Mei, D. -M.; Mock, J.; Moongweluwan, M.; Morad, J.; Murphy, A. St.J.; Nehrkorn, C.; Nelson, H.; Neves, F.; Ott, R. A.; Pangilinan, M.; Parker, P. D.; Pease, E. K.; Pech, K.; Phelps, P.; Reichhart, L.; Shutt, T.; Silva, C.; Solovov, V. N.; Sorensen, P.; O'Sullivan, K.; Sumner, T. J.; Szydagis, M.; Taylor, D.; Tennyson, B.; Tiedt, D. R.; Tripathi, M.; Uvarov, S.; Verbus, J. R.; Walsh, N.; Webb, R.; White, J. T.; Witherell, M. S.; Wolfs, F. L.H.; Woods, M.; Zhang, C.

    2015-01-01

    The LUX detector is currently in operation at the Davis Campus at the 4850’ level of the Sanford Underground Research Facility (SURF) in Lead, SD to directly search for WIMP dark matter. Knowing the type and rate of backgrounds is critical in a rare, low energy event search, and LUX was designed, constructed, and deployed to mitigate backgrounds, both internal and external. An important internal background are decays of radon and its daughters. These consist of alpha decays, which are easily tagged and are a tracer of certain backgrounds, and beta decays, some of which are not as readily tagged and present a background for the WIMP search. We report on studies of alpha decay and discuss implications for the WIMP search.

  16. Cosmic Microwave Background Data Analysis

    NASA Astrophysics Data System (ADS)

    Paykari, Paniez; Starck, Jean-Luc Starck

    2012-03-01

    About 400,000 years after the Big Bang the temperature of the Universe fell to about a few thousand degrees. As a result, the previously free electrons and protons combined and the Universe became neutral. This released a radiation which we now observe as the cosmic microwave background (CMB). The tiny fluctuations* in the temperature and polarization of the CMB carry a wealth of cosmological information. These so-called temperature anisotropies were predicted as the imprints of the initial density perturbations which gave rise to the present large-scale structures such as galaxies and clusters of galaxies. This relation between the present-day Universe and its initial conditions has made the CMB radiation one of the most preferred tools to understand the history of the Universe. The CMB radiation was discovered by radio astronomers Arno Penzias and Robert Wilson in 1965 [72] and earned them the 1978 Nobel Prize. This discovery was in support of the Big Bang theory and ruled out the only other available theory at that time - the steady-state theory. The crucial observations of the CMB radiation were made by the Far-Infrared Absolute Spectrophotometer (FIRAS) instrument on the Cosmic Background Explorer (COBE) satellite [86]- orbited in 1989-1996. COBE made the most accurate measurements of the CMB frequency spectrum and confirmed it as being a black-body to within experimental limits. This made the CMB spectrum the most precisely measured black-body spectrum in nature. The CMB has a thermal black-body spectrum at a temperature of 2.725 K: the spectrum peaks in the microwave range frequency of 160.2 GHz, corresponding to a 1.9mmwavelength. The results of COBE inspired a series of ground- and balloon-based experiments, which measured CMB anisotropies on smaller scales over the next decade. During the 1990s, the first acoustic peak of the CMB power spectrum (see Figure 5.1) was measured with increasing sensitivity and by 2000 the BOOMERanG experiment [26] reported

  17. Firearm Acquisition Without Background Checks: Results of a National Survey.

    PubMed

    Miller, Matthew; Hepburn, Lisa; Azrael, Deborah

    2017-02-21

    In 1994, 40% of U.S. gun owners who had recently acquired a firearm did so without a background check. No contemporary estimates exist. To estimate the proportion of current U.S. gun owners who acquired their most recent firearm without a background check, by time since and manner of acquisition, for the nation as a whole and separately in states with and without legislation regulating private sales. Probability-based online survey. United States, 2015. 1613 adult gun owners. Current gun owners were asked where and when they acquired their last firearm; if they purchased the firearm; and whether, as part of that acquisition, they had a background check (or were asked to show a firearm license or permit). 22% (95% CI, 16% to 27%) of gun owners who reported obtaining their most recent firearm within the previous 2 years reported doing so without a background check. For firearms purchased privately within the previous 2 years (that is, other than from a store or pawnshop, including sales between individuals in person, online, or at gun shows), 50% (CI, 35% to 65%) were obtained without a background check. This percentage was 26% (CI, 5% to 47%) for owners residing in states regulating private firearm sales and 57% (CI, 40% to 75%) for those living in states without regulations on private firearm sales. Potential inaccuracies due to recall and social desirability bias. 22% of current U.S. gun owners who acquired a firearm within the past 2 years did so without a background check. Although this represents a smaller proportion of gun owners obtaining firearms without background checks than in the past, millions of U.S. adults continue to acquire guns without background checks, especially in states that do not regulate private firearm sales. Fund for a Safer Future and the Joyce Foundation.

  18. Current limiters

    SciTech Connect

    Loescher, D.H.; Noren, K.

    1996-09-01

    The current that flows between the electrical test equipment and the nuclear explosive must be limited to safe levels during electrical tests conducted on nuclear explosives at the DOE Pantex facility. The safest way to limit the current is to use batteries that can provide only acceptably low current into a short circuit; unfortunately this is not always possible. When it is not possible, current limiters, along with other design features, are used to limit the current. Three types of current limiters, the fuse blower, the resistor limiter, and the MOSFET-pass-transistor limiters, are used extensively in Pantex test equipment. Detailed failure mode and effects analyses were conducted on these limiters. Two other types of limiters were also analyzed. It was found that there is no best type of limiter that should be used in all applications. The fuse blower has advantages when many circuits must be monitored, a low insertion voltage drop is important, and size and weight must be kept low. However, this limiter has many failure modes that can lead to the loss of over current protection. The resistor limiter is simple and inexpensive, but is normally usable only on circuits for which the nominal current is less than a few tens of milliamperes. The MOSFET limiter can be used on high current circuits, but it has a number of single point failure modes that can lead to a loss of protective action. Because bad component placement or poor wire routing can defeat any limiter, placement and routing must be designed carefully and documented thoroughly.

  19. [Tobacco abuse: background and countermeasures].

    PubMed

    Bolliger, C T

    1998-01-14

    The extreme extent of world-wide tobacco consumption, mainly in the form of cigarette smoking, is a phenomenon of the 20th century and can be termed a pandemic. Partly due to the massive and uninhibited advertising of the tobacco companies smoking prevalence has dramatically increased until the mid-sixties. Since then thousands of reports on the damaging-effects of smoking have been published which has led to a change in attitude and to a decrease in smoking prevalence at least in industrialised countries. In Switzerland about 25% of the adult population smoke, but the percentage in the age group between 25 to 34 years is significantly higher. Smoking is the most important preventable cause of disease; this has been underlined by recent findings that about 50% of smokers will eventually die from their habit. Regular smokers-usually defined as regularly smoking more than 10-15 cigarettes daily-are nicotine dependent and do not smoke because they want to, but because they have to. Although 60-70% of smokers would like to quit, they fail without help. Nevertheless, smoking cessation is possible: the most important issue is the smoker's own motivation. Psychological counselling and nicotine replacement therapy (NRT) given as either patch, chewing gum, or nasal spray are merely aids to enhance success. With intensive counselling and NRT a maximum success rate of about 30% can be expected assessed 1 year after quit date. In general the use of NRT doubles the success rate of any chosen form of intervention. Cessation of smoking in young people is currently considered the best form of prevention.

  20. 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}

  1. The microwave background anisotropies: Observations

    PubMed Central

    Wilkinson, David

    1998-01-01

    Most cosmologists now believe that we live in an evolving universe that has been expanding and cooling since its origin about 15 billion years ago. Strong evidence for this standard cosmological model comes from studies of the cosmic microwave background radiation (CMBR), the remnant heat from the initial fireball. The CMBR spectrum is blackbody, as predicted from the hot Big Bang model before the discovery of the remnant radiation in 1964. In 1992 the cosmic background explorer (COBE) satellite finally detected the anisotropy of the radiation—fingerprints left by tiny temperature fluctuations in the initial bang. Careful design of the COBE satellite, and a bit of luck, allowed the 30 μK fluctuations in the CMBR temperature (2.73 K) to be pulled out of instrument noise and spurious foreground emissions. Further advances in detector technology and experiment design are allowing current CMBR experiments to search for predicted features in the anisotropy power spectrum at angular scales of 1° and smaller. If they exist, these features were formed at an important epoch in the evolution of the universe—the decoupling of matter and radiation at a temperature of about 4,000 K and a time about 300,000 years after the bang. CMBR anisotropy measurements probe directly some detailed physics of the early universe. Also, parameters of the cosmological model can be measured because the anisotropy power spectrum depends on constituent densities and the horizon scale at a known cosmological epoch. As sophisticated experiments on the ground and on balloons pursue these measurements, two CMBR anisotropy satellite missions are being prepared for launch early in the next century. PMID:9419320

  2. Data analysis of cosmic microwave background experiments

    NASA Astrophysics Data System (ADS)

    Abroe, Matthew Edmund

    2004-12-01

    The cosmic microwave background (CMB) is a powerful tool for determining and constraining the fundamental properties of our universe. In this thesis we present various computational and statistical techniques used to analyze datasets from CMB experiments, and apply them to both simulated and actual datasets. The algorithms presented in this thesis perform a variety of tasks in relation to the goal of extracting scientific information from CMB data sets. The CMB anisotropy power spectrum is sensitive to numerous parameters that determine the evolutionary and large scale properties of our universe. Now that numerous experiments have mapped the CMB intensity fluctuations on overlapping regions of the sky it is important to ensure that the various experiments are indeed observing the same signal. We cross-correlate the cosmic microwave background temperature anisotropy maps from the WMAP, MAXIMA-I, and MAXIMA-II experiments. The results conclusively show that the three experiments not only display the same statistical properties of the CMB anisotropy, but also detect the same features wherever the observed sky areas overlap. We conclude that the contribution of systematic errors to these maps is negligible and that MAXIMA and WMAP have accurately mapped the cosmic microwave background anisotropy. Due to a quadrapole anisotropy at last scattering it is predicted that the CMB photons should be linearly polarized, and that the polarization intensity will be roughly an order of magnitude lower than the intensity fluctuations. Two computationally intensive methods for simulating the CMB polarization signal on the sky are presented. Now that CMB polarization experiments are currently producing data sets new algorithms for analyzing polarization time stream data must be developed and tested. We demonstrate how to generate simulations of a polarization experiment in the temporal domain and apply these simulations to the MAXIPOL case. We develop a maximum likelihood map making

  3. Alpha Backgrounds in the SNO ^3He Proportional Counter Array

    NASA Astrophysics Data System (ADS)

    Stonehill, Laura

    2006-04-01

    The Sudbury Neutrino Observatory (SNO) has recently deployed an array of proportional counters known as Neutral Current Detectors (NCDs) to detect thermalized neutrons via the ^3He(n,p)^3H reaction. The primary physics background to the neutron-capture signal is alpha particle emission from uranium- and thorium-chain decays in the NCD walls. The expected capture rate of neutrons from the neutral-current neutrino reaction on deuterium is three per day and the intrinsic alpha background rate is approximately 250 alphas per day. Fewer than 10% of these alphas fall into the energy range where neutron-capture signals occur, and a substantial number of these can be eliminated by pulse-shape analysis. This talk will focus on measurements of the alpha backgrounds in the NCDs and the extent to which these alphas contaminate the neutron-capture signal region.

  4. Methods and reagents. Reducing background colonies with positive selection vectors.

    PubMed

    Hengen, P N

    1997-03-01

    Methods and reagents is a unique monthly column that highlights current discussions in the newsgroup bionet.molbio.methds-reagnts, available on the Internet. This month's column discusses the pros and cons of eliminating unwanted background colonies by using the positive selection vector pZErO. For details on how to partake in the newsgroup, see the accompanying box.

  5. The cosmic microwave background - A probe of particle physics

    NASA Technical Reports Server (NTRS)

    Silk, Joseph

    1990-01-01

    The current status of spectral distortions and angular anisotropies in the cosmic microwave background is reviewed, with emphasis on the role played by weakly interacting particle dark matter. Theoretical predictions and recent observational results are described, and prospects for future progress are summarized.

  6. Second Language Comprehensibility Revisited: Investigating the Effects of Learner Background

    ERIC Educational Resources Information Center

    Crowther, Dustin; Trofimovich, Pavel; Saito, Kazuya; Isaacs, Talia

    2015-01-01

    The current study investigated first language (L1) effects on listener judgment of comprehensibility and accentedness in second language (L2) speech. The participants were 45 university-level adult speakers of English from three L1 backgrounds (Chinese, Hindi, Farsi), performing a picture narrative task. Ten native English listeners used…

  7. The cosmic microwave background - A probe of particle physics

    NASA Technical Reports Server (NTRS)

    Silk, Joseph

    1990-01-01

    The current status of spectral distortions and angular anisotropies in the cosmic microwave background is reviewed, with emphasis on the role played by weakly interacting particle dark matter. Theoretical predictions and recent observational results are described, and prospects for future progress are summarized.

  8. Background Materials on Collective Bargaining for Teachers. A Conference Guide.

    ERIC Educational Resources Information Center

    Nolte, M. Chester; Linn, John Phillip

    Intended as background material for the annual meeting of the Education Commission of the States, this document attempts to answer basic questions inherent in teacher negotiations. The first section discusses teacher militancy, current status of legislation, and contents of teacher negotiation laws. The second section considers issues facing…

  9. Center background shows two fortyhorsepower directcurrent electric motors installed in ...

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

    Center background shows two forty-horsepower direct-current electric motors installed in 1904 to provide power to two drive shafts for first floor machine shops. - Thomas A. Edison Laboratories, Building No. 5, Main Street & Lakeside Avenue, West Orange, Essex County, NJ

  10. Second Language Comprehensibility Revisited: Investigating the Effects of Learner Background

    ERIC Educational Resources Information Center

    Crowther, Dustin; Trofimovich, Pavel; Saito, Kazuya; Isaacs, Talia

    2015-01-01

    The current study investigated first language (L1) effects on listener judgment of comprehensibility and accentedness in second language (L2) speech. The participants were 45 university-level adult speakers of English from three L1 backgrounds (Chinese, Hindi, Farsi), performing a picture narrative task. Ten native English listeners used…

  11. 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.

  12. Product Aspect Clustering by Incorporating Background Knowledge for Opinion Mining.

    PubMed

    Chen, Yiheng; Zhao, Yanyan; Qin, Bing; Liu, Ting

    2016-01-01

    Product aspect recognition is a key task in fine-grained opinion mining. Current methods primarily focus on the extraction of aspects from the product reviews. However, it is also important to cluster synonymous extracted aspects into the same category. In this paper, we focus on the problem of product aspect clustering. The primary challenge is to properly cluster and generalize aspects that have similar meanings but different representations. To address this problem, we learn two types of background knowledge for each extracted aspect based on two types of effective aspect relations: relevant aspect relations and irrelevant aspect relations, which describe two different types of relationships between two aspects. Based on these two types of relationships, we can assign many relevant and irrelevant aspects into two different sets as the background knowledge to describe each product aspect. To obtain abundant background knowledge for each product aspect, we can enrich the available information with background knowledge from the Web. Then, we design a hierarchical clustering algorithm to cluster these aspects into different groups, in which aspect similarity is computed using the relevant and irrelevant aspect sets for each product aspect. Experimental results obtained in both camera and mobile phone domains demonstrate that the proposed product aspect clustering method based on two types of background knowledge performs better than the baseline approach without the use of background knowledge. Moreover, the experimental results also indicate that expanding the available background knowledge using the Web is feasible.

  13. Product Aspect Clustering by Incorporating Background Knowledge for Opinion Mining

    PubMed Central

    Chen, Yiheng; Zhao, Yanyan; Qin, Bing; Liu, Ting

    2016-01-01

    Product aspect recognition is a key task in fine-grained opinion mining. Current methods primarily focus on the extraction of aspects from the product reviews. However, it is also important to cluster synonymous extracted aspects into the same category. In this paper, we focus on the problem of product aspect clustering. The primary challenge is to properly cluster and generalize aspects that have similar meanings but different representations. To address this problem, we learn two types of background knowledge for each extracted aspect based on two types of effective aspect relations: relevant aspect relations and irrelevant aspect relations, which describe two different types of relationships between two aspects. Based on these two types of relationships, we can assign many relevant and irrelevant aspects into two different sets as the background knowledge to describe each product aspect. To obtain abundant background knowledge for each product aspect, we can enrich the available information with background knowledge from the Web. Then, we design a hierarchical clustering algorithm to cluster these aspects into different groups, in which aspect similarity is computed using the relevant and irrelevant aspect sets for each product aspect. Experimental results obtained in both camera and mobile phone domains demonstrate that the proposed product aspect clustering method based on two types of background knowledge performs better than the baseline approach without the use of background knowledge. Moreover, the experimental results also indicate that expanding the available background knowledge using the Web is feasible. PMID:27561001

  14. 25 CFR 556.4 - Background investigations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 2 2012-04-01 2012-04-01 false Background investigations. 556.4 Section 556.4 Indians NATIONAL INDIAN GAMING COMMISSION, DEPARTMENT OF THE INTERIOR GAMING LICENSES AND BACKGROUND INVESTIGATIONS FOR KEY EMPLOYEES AND PRIMARY MANAGEMENT OFFICIALS BACKGROUND INVESTIGATIONS FOR PRIMARY MANAGEMENT...

  15. 25 CFR 556.4 - Background investigations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false Background investigations. 556.4 Section 556.4 Indians NATIONAL INDIAN GAMING COMMISSION, DEPARTMENT OF THE INTERIOR GAMING LICENSES AND BACKGROUND INVESTIGATIONS FOR KEY EMPLOYEES AND PRIMARY MANAGEMENT OFFICIALS BACKGROUND INVESTIGATIONS FOR PRIMARY MANAGEMENT...

  16. 45 CFR 650.16 - Background rights.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Background rights. 650.16 Section 650.16 Public... Background rights. The Foundation will acquire rights to a research performer's pre-existing technology only... of the cognizant Program Manager, will negotiate a background rights provision. If the...

  17. 16 CFR 1101.1 - General background.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 2 2011-01-01 2011-01-01 false General background. 1101.1 Section 1101.1 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS INFORMATION DISCLOSURE UNDER SECTION 6(b) OF THE CONSUMER PRODUCT SAFETY ACT Background § 1101.1 General background....

  18. 16 CFR 1101.1 - General background.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false General background. 1101.1 Section 1101.1 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS INFORMATION DISCLOSURE UNDER SECTION 6(b) OF THE CONSUMER PRODUCT SAFETY ACT Background § 1101.1 General background. (a) Basic purpose. This rule sets...

  19. Current Titles

    SciTech Connect

    Various

    2006-06-01

    This booklet is published for those interested in current research being conducted at the National Center for Electron Microscopy. The NCEM is a DOE-designated national user facility and is available at no charge to qualified researchers. Access is controlled by an external steering committee. Interested researchers may contact Jane Cavlina, Administrator, at 510/486-6036.

  20. Probing Inflation via Cosmic Microwave Background Polarimetry

    NASA Technical Reports Server (NTRS)

    Chuss, David T.

    2008-01-01

    The Cosmic Microwave Background (CMB) has been a rich source of information about the early Universe. Detailed measurements of its spectrum and spatial distribution have helped solidify the Standard Model of Cosmology. However, many questions still remain. Standard Cosmology does not explain why the early Universe is geometrically flat, expanding, homogenous across the horizon, and riddled with a small anisotropy that provides the seed for structure formation. Inflation has been proposed as a mechanism that naturally solves these problems. In addition to solving these problems, inflation is expected to produce a spectrum of gravitational waves that will create a particular polarization pattern on the CMB. Detection of this polarized signal is a key test of inflation and will give a direct measurement of the energy scale at which inflation takes place. This polarized signature of inflation is expected to be -9 orders of magnitude below the 2.7 K monopole level of the CMB. This measurement will require good control of systematic errors, an array of many detectors having the requisite sensitivity, and a reliable method for removing polarized foregrounds, and nearly complete sky coverage. Ultimately, this measurement is likely to require a space mission. To this effect, technology and mission concept development are currently underway.

  1. Observations and Modeling of Seismic Background Noise

    USGS Publications Warehouse

    Peterson, Jon R.

    1993-01-01

    INTRODUCTION The preparation of this report had two purposes. One was to present a catalog of seismic background noise spectra obtained from a worldwide network of seismograph stations. The other purpose was to refine and document models of seismic background noise that have been in use for several years. The second objective was, in fact, the principal reason that this study was initiated and influenced the procedures used in collecting and processing the data. With a single exception, all of the data used in this study were extracted from the digital data archive at the U.S. Geological Survey's Albuquerque Seismological Laboratory (ASL). This archive dates from 1972 when ASL first began deploying digital seismograph systems and collecting and distributing digital data under the sponsorship of the Defense Advanced Research Projects Agency (DARPA). There have been many changes and additions to the global seismograph networks during the past twenty years, but perhaps none as significant as the current deployment of very broadband seismographs by the U.S. Geological Survey (USGS) and the University of California San Diego (UCSD) under the scientific direction of the IRIS consortium. The new data acquisition systems have extended the bandwidth and resolution of seismic recording, and they utilize high-density recording media that permit the continuous recording of broadband data. The data improvements and continuous recording greatly benefit and simplify surveys of seismic background noise. Although there are many other sources of digital data, the ASL archive data were used almost exclusively because of accessibility and because the data systems and their calibration are well documented for the most part. Fortunately, the ASL archive contains high-quality data from other stations in addition to those deployed by the USGS. Included are data from UCSD IRIS/IDA stations, the Regional Seismic Test Network (RSTN) deployed by Sandia National Laboratories (SNL), and the

  2. 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.

  3. Vlasov simulations of collisionless magnetic reconnection without background density

    NASA Astrophysics Data System (ADS)

    Schmitz, H.; Grauer, R.

    2008-02-01

    A standard starting point for the simulation of collisionless reconnection is the Harris equilibrium which is made up of a current sheet that separates two regions of opposing magnetic field. Magnetohydrodynamic simulations of collisionless reconnection usually include a homogeneous background density for reasons of numerical stability. While, in some cases, this is a realistic assumption, the background density may introduce new effects both due to the more involved structure of the distribution function or due to the fact that the Alfvèn speed remains finite far away from the current sheet. We present a fully kinetic Vlasov simulation of the perturbed Harris equilibrium using a Vlasov code. Parameters are chosen to match the Geospace Environment Modeling (GEM) Magnetic Reconnection Challenge but excluding the background density. This allows to compare with earlier simulations [Schmitz H, Grauer R. Kinetic Vlasov simulations of collisionless magnetic reconnection. Phys Plasmas 2006;13:092309] which include the background density. It is found that the absence of a background density causes the reconnection rate to be higher. On the other hand, the time until the onset of reconnection is hardly affected. Again the off diagonal elements of the pressure tensor are found to be important on the X-line but with modified importance for the individual terms.

  4. The transport of photochemical pollutants to the background troposphere

    NASA Technical Reports Server (NTRS)

    Bazzell, C. C.; Peters, L. K.

    1981-01-01

    The considered investigation is concerned with the phenomena occurring as a chemically reacting plume, with specific initial concentrations of NO, NO2, O3, and hydrocarbons, emerges from an urban area and is advected to the background troposphere. A better understanding of the global NOx and hydrocarbon budgets can be realized by determining the fractions of NOx and hydrocarbons that are transported to distances far enough to be considered background. The investigation makes use of a 56-step, lumped kinetic mechanism for photochemical smog, which includes current information on pertinent chemical reactions and rate constants for the reactions.

  5. Delayed offset detection on figures relative to backgrounds.

    PubMed

    Hecht, Lauren N; Vecera, Shaun P

    2011-11-17

    Recent research suggests that perceptual processing begins earlier for figures than for background regions (B. D. Lester, L. N. Hecht, & S. P. Vecera, 2009). This "prior entry" effect begins to account for reported figural benefits. However, another difference in perceptual processing may also contribute to these observed reports: Figures may also be afforded additional perceptual processing. The current experiments examined this claim and provide evidence that targets presented on figures are perceived as offsetting later than targets appearing on grounds, suggesting extended processing of figures relative to background regions.

  6. Big bang nucleosynthesis, cosmic microwave background anisotropies and dark energy

    NASA Astrophysics Data System (ADS)

    Signore, Monique; Puy, Denis

    2002-05-01

    Over the last decade, cosmological observations have attained a level of precision which allows for very detailed comparison with theoretical predictions. We are beginning to learn the answers to some fundamental questions, using information contained in Cosmic Microwave Background Anisotropy (CMBA) data. In this talk, we briefly review some studies of the current and prospected constraints imposed by CMBA measurements on the neutrino physics and on the dark energy. As it was already announced by Scott [1], we present some possible new physics from the Cosmic Microwave Background (CMB). .

  7. Reducing background effects in orchards through spectral vegetation index correction

    NASA Astrophysics Data System (ADS)

    Van Beek, Jonathan; Tits, Laurent; Somers, Ben; Deckers, Tom; Janssens, Pieter; Coppin, Pol

    2015-02-01

    Satellite remote sensing provides an alternative to time-consuming and labor intensive in situ measurements of biophysical variables in agricultural crops required for precision agriculture applications. In orchards, however, the spatial resolution causes mixtures of canopies and background (i.e. soil, grass and shadow), hampering the estimation of these biophysical variables. Furthermore, variable background mixtures obstruct meaningful comparisons between different orchard blocks, rows or within each row. Current correction methodologies use spectral differences between canopies and background, but struggle with a vegetated orchard floor. This background influence and the lack of a generic solution are addressed in this study. Firstly, the problem was demonstrated in a controlled environment for vegetation indices sensitive to chlorophyll content, water content and leaf area index. Afterwards, traditional background correction methods (i.e. soil-adjusted vegetation indices and signal unmixing) were compared to the proposed vegetation index correction. This correction was based on the mixing degree of each pixel (i.e. tree cover fraction) to rescale the vegetation indices accordingly and was applied to synthetic and WorldView-2 satellite imagery. Through the correction, the effect of background admixture for vegetation indices was reduced, and the estimation of biophysical variables was improved (ΔR2 = 0.2-0.31).

  8. Student criminal background checks in colleges of allied health.

    PubMed

    Wyatt, Diane; Aziz, Hassan; Mahoney, Sherry; Gilman, Frances H

    2008-01-01

    The demand that criminal background checks be performed for students in allied health schools and programs has soared in recent years. The need for criminal background checks on students entering the health care professions has emerged as a critical issue largely due to requirements by clinical affiliate training sites. The Joint Commission published a standard stating, "for staff, students and volunteers who work in the same capacity as staff who provide care, treatment, and services, at Elements of Performance 5 states criminal background checks are verified when required by law and regulation and organization policy." More simply stated, this means that criminal background check records must be verifiable if required by some authoritative entity such as state law. However, whether by misinterpretation of the standard or through conscious decision by organization policy makers, many health care organizations suddenly began to require criminal background checks as part of their affiliation agreements with health related schools or programs. The focus of this study was to identify current practices of allied health institutions regarding their conduct of criminal background checks on students entering the allied health professions.

  9. Current titles

    SciTech Connect

    1995-07-01

    This booklet is published for those interested in current research being conducted at the National Center for Electron Microscopy. The NCEM is a DOE-designated national user facility and is available at no charge to qualified researchers. Access is controlled by an external steering committee. Interested researchers may contact Gretchen Hermes at (510) 486-5006 or address below for a User`s Guide. Copies of available papers can be ordered from: Theda Crawford National Center for Electron Microscopy, Lawrence Berkeley Laboratory, One Cyclotron Rd., MS72, Berkeley, California, USA 94720.

  10. The neuromuscular impact of symptomatic SMN restoration in a mouse model of spinal muscular atrophy

    PubMed Central

    Arnold, W. David; McGovern, Vicki L.; Sanchez, Benjamin; Li, Jia; Corlett, Kaitlyn M.; Kolb, Stephen J.; Rutkove, Seward B.; Burghes, Arthur H.

    2016-01-01

    Background Significant advances in the development of SMN-restoring therapeutics have occurred since 2010 when very effective biological treatments were reported in mouse models of spinal muscular atrophy. As these treatments are applied in human clinical trials, there is pressing need to define quantitative assessments of disease progression, treatment stratification, and therapeutic efficacy. The electrophysiological measures Compound Muscle Action Potential and Motor Unit Number Estimation are reliable measures of nerve function. In both the SMNΔ7 mouse and a pig model of spinal muscular atrophy, early SMN restoration results in preservation of electrophysiological measures. Currently, clinical trials are underway in patients at post-symptomatic stages of disease progression. In this study, we present results from both early and delayed SMN restoration using clinically-relevant measures including electrical impedance myography, compound muscle action potential, and motor unit number estimation to quantify the efficacy and time-sensitivity of SMN-restoring therapy. Methods SMAΔ7 mice were treated via intracerebroventricular injection with antisense oligonucleotides targeting ISS-N1 to increase SMN protein from the SMN2 gene on postnatal day 2, 4, or 6 and compared with sham-treated spinal muscular atrophy and control mice. Compound muscle action potential and motor unit number estimation of the triceps surae muscles were performed at day 12, 21, and 30 by a single evaluator blinded to genotype and treatment. Similarly, electrical impedance myography was measured on the biceps femoris muscle at 12 days for comparison. Results Electrophysiological measures and electrical impedance myography detected significant differences at 12 days between control and late-treated (4 or 6 days) and sham-treated spinal muscular atrophy mice, but not in mice treated at 2 days(p<0.01). EIM findings paralleled and correlated with compound muscle action potential and motor unit

  11. Generalized duality in curved string backgrounds

    NASA Astrophysics Data System (ADS)

    Giveon, Amit; Roček, Martin

    1992-08-01

    The elements of O(d, d, Z) are shown to be discrete symmetries of the space of curved string backgrounds that are independent of d coordinates. The explicit action of the symmetries on the backgrounds is described. Particular attention is paid to the dilaton transformation. Such symmetries identify different cosmological solutions and other (possibly) singular backgrounds; for example, it is shown that a compact black string is dual to a charged black hole. The extension to the heterotic string is discussed.

  12. Background removal procedure for rapid scan EPR.

    PubMed

    Tseitlin, Mark; Czechowski, Tomasz; Quine, Richard W; Eaton, Sandra S; Eaton, Gareth R

    2009-01-01

    In rapid scan EPR the changing magnetic field creates a background signal with components at the scan frequency and its harmonics. The amplitude of the background signal increases with scan width and is more significant for weak EPR signals such as are obtained in the presence of magnetic field gradients. A procedure for distinguishing this background from the EPR signal is proposed, mathematically described, and tested for various experimental conditions.

  13. Cosmic Background Explorer (COBE) press kit

    NASA Technical Reports Server (NTRS)

    1989-01-01

    COBE, the Cosmic Background Explorer spacecraft, and its mission are described. COBE was designed to study the origin and dynamics of the universe including the theory that the universe began with a cataclysmic explosion referred to as the Big Bang. To this end, earth's cosmic background - the infrared radiation that bombards earth from every direction - will be measured by three sophisticated instruments: the Differential Microwave Radiometer (DMR), the Far Infrared Absolute Spectrophotometer (FIRAS), and the Diffuse Infrared Background Experiment (DIRBE).

  14. Review of Monte Carlo simulations for backgrounds from radioactivity

    SciTech Connect

    Selvi, Marco

    2013-08-08

    For all experiments dealing with the rare event searches (neutrino, dark matter, neutrino-less double-beta decay), the reduction of the radioactive background is one of the most important and difficult tasks. There are basically two types of background, electron recoils and nuclear recoils. The electron recoil background is mostly from the gamma rays through the radioactive decay. The nuclear recoil background is from neutrons from spontaneous fission, (α, n) reactions and muoninduced interactions (spallations, photo-nuclear and hadronic interaction). The external gammas and neutrons from the muons and laboratory environment, can be reduced by operating the detector at deep underground laboratories and by placing active or passive shield materials around the detector. The radioactivity of the detector materials also contributes to the background; in order to reduce it a careful screening campaign is mandatory to select highly radio-pure materials. In this review I present the status of current Monte Carlo simulations aimed to estimate and reproduce the background induced by gamma and neutron radioactivity of the materials and the shield of rare event search experiment. For the electromagnetic background a good level of agreement between the data and the MC simulation has been reached by the XENON100 and EDELWEISS experiments, using the GEANT4 toolkit. For the neutron background, a comparison between the yield of neutrons from spontaneous fission and (α, n) obtained with two dedicated softwares, SOURCES-4A and the one developed by Mei-Zhang-Hime, show a good overall agreement, with total yields within a factor 2 difference. The energy spectra from SOURCES-4A are in general smoother, while those from MZH presents sharp peaks. The neutron propagation through various materials has been studied with two MC codes, GEANT4 and MCNPX, showing a reasonably good agreement, inside 50% discrepancy.

  15. Review of Monte Carlo simulations for backgrounds from radioactivity

    NASA Astrophysics Data System (ADS)

    Selvi, Marco

    2013-08-01

    For all experiments dealing with the rare event searches (neutrino, dark matter, neutrino-less double-beta decay), the reduction of the radioactive background is one of the most important and difficult tasks. There are basically two types of background, electron recoils and nuclear recoils. The electron recoil background is mostly from the gamma rays through the radioactive decay. The nuclear recoil background is from neutrons from spontaneous fission, (α, n) reactions and muoninduced interactions (spallations, photo-nuclear and hadronic interaction). The external gammas and neutrons from the muons and laboratory environment, can be reduced by operating the detector at deep underground laboratories and by placing active or passive shield materials around the detector. The radioactivity of the detector materials also contributes to the background; in order to reduce it a careful screening campaign is mandatory to select highly radio-pure materials. In this review I present the status of current Monte Carlo simulations aimed to estimate and reproduce the background induced by gamma and neutron radioactivity of the materials and the shield of rare event search experiment. For the electromagnetic background a good level of agreement between the data and the MC simulation has been reached by the XENON100 and EDELWEISS experiments, using the GEANT4 toolkit. For the neutron background, a comparison between the yield of neutrons from spontaneous fission and (α, n) obtained with two dedicated softwares, SOURCES-4A and the one developed by Mei-Zhang-Hime, show a good overall agreement, with total yields within a factor 2 difference. The energy spectra from SOURCES-4A are in general smoother, while those from MZH presents sharp peaks. The neutron propagation through various materials has been studied with two MC codes, GEANT4 and MCNPX, showing a reasonably good agreement, inside 50% discrepancy.

  16. Measurement of Acceptable Noise Level with Background Music

    PubMed Central

    Ahn, Hyun-Jung; Bahng, Junghwa

    2015-01-01

    Background and Objectives Acceptable noise level (ANL) is a measure of the maximum background noise level (BNL) that a person is willing to tolerate while following a target story. Although researchers have used various sources of target sound in ANL measures, a limited type of background noise has been used. Extending the previous study of Gordon-Hickey & Moore (2007), the current study determined the effect of music genre and tempo on ANLs as possible factors affecting ANLs. We also investigated the relationships between individual ANLs and the familiarity of music samples and between music ANLs and subjective preference. Subjects and Methods Forty-one participants were seperated into two groups according to their ANLs, 29 low-ANL listeners and 12 high-ANL listeners. Using Korean ANL material, the individual ANLs were measured based on the listeners' most comfortable listening level and BNL. The ANLs were measured in six conditions, with different music tempo (fast, slow) and genre (K-pop, pop, classical) in a counterbalanced order. Results Overall, ANLs did not differ by the tempo of background music, but music genre significantly affected individual ANLs. We observed relatively higher ANLs with K-pop music and relatively lower ANLs with classical music. This tendency was similar in both low-ANL and high-ANL groups. However, the subjective ratings of music familiarity and preference affected ANLs differently for low-ANL and high-ANL groups. In contrast to the low-ANL listeners, the ANLs of the high-ANL listeners were significantly affected by music familiarity and preference. Conclusions The genre of background music affected ANLs obtained using background music. The degree of music familiarity and preference appears to be associated with individual susceptibility to background music only for listeners who are greatly annoyed by background noise (high-ANL listeners). PMID:26413573

  17. Primordial helium and the cosmic background radiation

    SciTech Connect

    Steigman, Gary

    2010-04-01

    The products of primordial nucleosynthesis, along with the cosmic microwave background (CMB) photons, are relics from the early evolution of the Universe whose observations probe the standard model of cosmology and provide windows on new physics beyond the standard models of cosmology and of particle physics. According to the standard, hot big bang cosmology, long before any stars have formed a significant fraction ( ∼ 25%) of the baryonic mass in the Universe should be in the form of helium-4 nuclei. Since current observations of {sup 4}He are restricted to low redshift regions where stellar nucleosynthesis has occurred, an observation of high redshift, prestellar, truly primordial {sup 4}He would constitute a fundamental test of the hot, big bang cosmology. At recombination, long after big bang nucleosynthesis (BBN) has ended, the temperature anisotropy spectrum imprinted on the CMB depends on the {sup 4}He abundance through its connection to the electron density and the effect of the electron density on Silk damping. Since the relic abundance of {sup 4}He is relatively insensitive to the universal density of baryons, but is sensitive to a non-standard, early Universe expansion rate, the primordial mass fraction of {sup 4}He, Yp, offers a test of the consistency of the standard models of BBN and the CMB and, provides constraints on non-standard physics. Here, the WMAP seven year data (supplemented by other CMB experiments), which lead to an indirect determination of Yp at high redshift, are compared to the BBN predictions and to the independent, direct observations of {sup 4}He in low redshift, extragalactic HII regions. At present, given the very large uncertainties in the CMB-determined primordial {sup 4}He abundance (as well as for the helium abundances inferred from HII region observations), any differences between the BBN predictions and the CMB observations are small, at a level ∼<1.5σ.

  18. Hanford Site background: Part 1, Soil background for nonradioactive analytes. Revision 1, Volume 2

    SciTech Connect

    Not Available

    1993-04-01

    Volume two contains the following appendices: Description of soil sampling sites; sampling narrative; raw data soil background; background data analysis; sitewide background soil sampling plan; and use of soil background data for the detection of contamination at waste management unit on the Hanford Site.

  19. Analysis of Alpha Backgrounds in DarkSide-50

    NASA Astrophysics Data System (ADS)

    Monte, Alissa; DarkSide Collaboration

    2017-01-01

    DarkSide-50 is the current phase of the DarkSide direct dark matter search program, operating underground at the Laboratori Nazionali del Gran Sasso in Italy. The detector is a dual-phase argon Time Projection Chamber (TPC), designed for direct detection of Weakly Interacting Massive Particles, and housed within an active veto system of liquid scintillator and water Cherenkov detectors. Since switching to a target of low radioactivity argon extracted from underground sources in April, 2016, the background is no longer dominated by naturally occurring 39Ar. However, alpha backgrounds from radon and its daughters remain, both from the liquid argon bulk and internal detector surfaces. I will present details of the analysis used to understand and quantify alpha backgrounds, as well as to understand other types of radon contamination that may be present, and our sensitivity to them.

  20. Background processes in the KATRIN main spectrometer

    NASA Astrophysics Data System (ADS)

    Fraenkle, F. M.; KATRIN collaboration

    2017-09-01

    The KArlsruhe TRItium Neutrino (KATRIN) experiment is a large-scale experiment which aims for the model-independent determination of the effective mass of electron anti-neutrinos with a sensitivity of 200 meV/c2. It investigates the kinematics of electrons from tritium β-decay close to the endpoint of the energy spectrum. Low statistics at the endpoint requires an equally low background rate below 0.01 counts per second. The measurement setup consists of a high luminosity windowless gaseous molecular tritium source (WGTS), a differential and cryogenic pumped electron transport and tritium retention section, a tandem spectrometer section (pre-spectrometer and main spectrometer) for energy analysis, followed by a detector system for counting transmitted beta decay electrons. The background characteristics of the KATRIN main spectrometer were investigated in detail during two commissioning measurement phases. Of particular interest were backgrounds due to the decay of radon in the volume of the spectrometer, cosmic-muon-induced backgrounds, backgrounds due to natural radioactivity and Penning-discharge-related backgrounds. This proceeding will present results of the commissioning measurements and focuses on different background processes and their contribution to the overall background of the KATRIN experiment.

  1. 45 CFR 650.16 - Background rights.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 3 2012-10-01 2012-10-01 false Background rights. 650.16 Section 650.16 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION PATENTS § 650.16 Background rights. The Foundation will acquire rights to a research performer's pre-existing technology...

  2. 47 CFR 201.0 - Background.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Background. 201.0 Section 201.0 Telecommunication OFFICE OF SCIENCE AND TECHNOLOGY POLICY AND NATIONAL SECURITY COUNCIL EXECUTIVE POLICY § 201.0 Background. National policy with respect to the conservation, allocation and use of the...

  3. 47 CFR 201.0 - Background.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Background. 201.0 Section 201.0 Telecommunication OFFICE OF SCIENCE AND TECHNOLOGY POLICY AND NATIONAL SECURITY COUNCIL EXECUTIVE POLICY § 201.0 Background. National policy with respect to the conservation, allocation and use of the...

  4. Multiple Scatters in Single Site Gamma Backgrounds

    SciTech Connect

    Brodsky, J. P.

    2016-09-16

    nEXO aims to reduce its gamma backgrounds by taking advantage of the fact that a large number of gammas that would otherwise be backgrounds will undergo multiple compton scattering in the TPC and produce spatially distinct signals. These multi-sited (MS) events can be excluded from the 0νββ search.

  5. 47 CFR 32.1 - Background.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Background. 32.1 Section 32.1 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES UNIFORM SYSTEM OF ACCOUNTS FOR TELECOMMUNICATIONS COMPANIES Preface § 32.1 Background. The revised Uniform System of Accounts (USOA) is a...

  6. 47 CFR 32.1 - Background.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Background. 32.1 Section 32.1 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES UNIFORM SYSTEM OF ACCOUNTS FOR TELECOMMUNICATIONS COMPANIES Preface § 32.1 Background. The revised Uniform System of Accounts (USOA) is a...

  7. 47 CFR 32.1 - Background.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Background. 32.1 Section 32.1 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES UNIFORM SYSTEM OF ACCOUNTS FOR TELECOMMUNICATIONS COMPANIES Preface § 32.1 Background. The revised Uniform System of Accounts (USOA) is a...

  8. 40 CFR 761.380 - Background.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Background. 761.380 Section 761.380 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT....380 Background. This subpart provides self-implementing criteria for validating the conditions for...

  9. 32 CFR 763.3 - Background.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 5 2011-07-01 2011-07-01 false Background. 763.3 Section 763.3 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY ISLANDS UNDER NAVY JURISDICTION RULES GOVERNING PUBLIC ACCESS Entry Regulations for Kaho'olawe Island, Hawaii § 763.3 Background. (a) Kaho'olawe Island...

  10. 32 CFR 763.3 - Background.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 5 2010-07-01 2010-07-01 false Background. 763.3 Section 763.3 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY ISLANDS UNDER NAVY JURISDICTION RULES GOVERNING PUBLIC ACCESS Entry Regulations for Kaho'olawe Island, Hawaii § 763.3 Background. (a) Kaho'olawe Island...

  11. 47 CFR 201.0 - Background.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Background. 201.0 Section 201.0 Telecommunication OFFICE OF SCIENCE AND TECHNOLOGY POLICY AND NATIONAL SECURITY COUNCIL EXECUTIVE POLICY § 201.0 Background. National policy with respect to the conservation, allocation and use of the...

  12. 47 CFR 201.0 - Background.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Background. 201.0 Section 201.0 Telecommunication OFFICE OF SCIENCE AND TECHNOLOGY POLICY AND NATIONAL SECURITY COUNCIL EXECUTIVE POLICY § 201.0 Background. National policy with respect to the conservation, allocation and use of the...

  13. 32 CFR 732.1 - Background.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 5 2011-07-01 2011-07-01 false Background. 732.1 Section 732.1 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY PERSONNEL NONNAVAL MEDICAL AND DENTAL CARE General § 732.1 Background. When a U.S. Navy or Marine Corps member or a Canadian Navy or Marine Corps member...

  14. 32 CFR 732.1 - Background.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 5 2013-07-01 2013-07-01 false Background. 732.1 Section 732.1 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY PERSONNEL NONNAVAL MEDICAL AND DENTAL CARE General § 732.1 Background. When a U.S. Navy or Marine Corps member or a Canadian Navy or Marine Corps member...

  15. 32 CFR 732.1 - Background.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 5 2012-07-01 2012-07-01 false Background. 732.1 Section 732.1 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY PERSONNEL NONNAVAL MEDICAL AND DENTAL CARE General § 732.1 Background. When a U.S. Navy or Marine Corps member or a Canadian Navy or Marine Corps member...

  16. 32 CFR 732.1 - Background.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 5 2014-07-01 2014-07-01 false Background. 732.1 Section 732.1 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY PERSONNEL NONNAVAL MEDICAL AND DENTAL CARE General § 732.1 Background. When a U.S. Navy or Marine Corps member or a Canadian Navy or Marine Corps member...

  17. 47 CFR 201.0 - Background.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Background. 201.0 Section 201.0 Telecommunication OFFICE OF SCIENCE AND TECHNOLOGY POLICY AND NATIONAL SECURITY COUNCIL EXECUTIVE POLICY § 201.0 Background. National policy with respect to the conservation, allocation and use of the...

  18. Child Care: State Requirements for Background Checks.

    ERIC Educational Resources Information Center

    Fagnoni, Cynthia

    Background checks involve gathering information from state and federal databases to determine if child care providers have a history of child abuse or other criminal convictions that would make them unacceptable for working with children. Background checks include state criminal history checks, state child abuse registry checks, and Federal Bureau…

  19. 36 CFR 401.3 - Background.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 3 2012-07-01 2012-07-01 false Background. 401.3 Section 401.3 Parks, Forests, and Public Property AMERICAN BATTLE MONUMENTS COMMISSION MONUMENTS AND MEMORIALS § 401.3 Background. Following World War I many American individuals, organizations and governmental...

  20. 36 CFR 401.3 - Background.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 3 2014-07-01 2014-07-01 false Background. 401.3 Section 401.3 Parks, Forests, and Public Property AMERICAN BATTLE MONUMENTS COMMISSION MONUMENTS AND MEMORIALS § 401.3 Background. Following World War I many American individuals, organizations and governmental...

  1. 36 CFR § 401.3 - Background.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 3 2013-07-01 2012-07-01 true Background. § 401.3 Section § 401.3 Parks, Forests, and Public Property AMERICAN BATTLE MONUMENTS COMMISSION MONUMENTS AND MEMORIALS § 401.3 Background. Following World War I many American individuals, organizations and governmental...

  2. 22 CFR 305.3 - Background investigations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 2 2014-04-01 2014-04-01 false Background investigations. 305.3 Section 305.3 Foreign Relations PEACE CORPS ELIGIBILITY AND STANDARDS FOR PEACE CORPS VOLUNTEER SERVICE § 305.3 Background investigations. Section 22 of the Peace Corps Act states that to ensure enrollment of a Volunteer...

  3. 22 CFR 305.3 - Background investigations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 2 2013-04-01 2009-04-01 true Background investigations. 305.3 Section 305.3 Foreign Relations PEACE CORPS ELIGIBILITY AND STANDARDS FOR PEACE CORPS VOLUNTEER SERVICE § 305.3 Background investigations. Section 22 of the Peace Corps Act states that to ensure enrollment of a Volunteer...

  4. 40 CFR 761.380 - Background.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Background. 761.380 Section 761.380... POLYCHLORINATED BIPHENYLS (PCBs) MANUFACTURING, PROCESSING, DISTRIBUTION IN COMMERCE, AND USE PROHIBITIONS....380 Background. This subpart provides self-implementing criteria for validating the conditions for use...

  5. Women's Health Initiative (WHI) Background and Overview

    MedlinePlus

    ... chronic diseases are the major causes of death, disability and frailty in older women of all races and socioeconomic backgrounds. This multi- ... CDC), and the National Institutes of Health. Eight University-based Prevention ... encouraged women of all races and socioeconomic backgrounds to adopt ...

  6. 32 CFR 732.1 - Background.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 5 2010-07-01 2010-07-01 false Background. 732.1 Section 732.1 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY PERSONNEL NONNAVAL MEDICAL AND DENTAL CARE General § 732.1 Background. When a U.S. Navy or Marine Corps member or a Canadian Navy or Marine Corps member...

  7. Characterization and Prediction of the SPI Background

    NASA Technical Reports Server (NTRS)

    Teegarden, B. J.; Jean, P.; Knodlseder, J.; Skinner, G. K.; Weidenspointer, G.

    2003-01-01

    The INTEGRAL Spectrometer, like most gamma-ray instruments, is background dominated. Signal-to-background ratios of a few percent are typical. The background is primarily due to interactions of cosmic rays in the instrument and spacecraft. It characteristically varies by +/- 5% on time scales of days. This variation is caused mainly by fluctuations in the interplanetary magnetic field that modulates the cosmic ray intensity. To achieve the maximum performance from SPI it is essential to have a high quality model of this background that can predict its value to a fraction of a percent. In this poster we characterize the background and its variability, explore various models, and evaluate the accuracy of their predictions.

  8. The research of moving object detection based on background difference compensation

    NASA Astrophysics Data System (ADS)

    Song, Yan-bin; Ying, Jie; Lu, Lin-li

    2013-08-01

    Moving object detection was implemented in dynamic background based on background difference compensation. Background differential can effectively segment the moving object in static background. But in moving video, the camera motion causes corresponding movement of the target and background, which makes the prospect moving object hard to separate from the background. In order to detect moving object, we can compensate the movement of the background and transfer the dynamic background to static. Moving object detection in static background image was implemented using a new weights updating method that the weights were updated during a certain period. This method based on classical Gaussian mixture model improved the efficiency of image segmentation greatly. Moving object detection in dynamic background was realized using background differential compensation. The global motion of the background was established according to the affined parameters model. The model parameters were estimated by feature points matching based on the search strategy. Invalid matching points were eliminated using the method of distance consistency. Backward mapping was used to get the motion parameters of the background. After compensation of the background with the global motion parameters, frame difference between the current frame and the background can detect moving objects effectively. Experiments were done on computer with the programming tools of VS2010 and MATLAB. Experimental results showed that the algorithm based on differential compensation was effective.

  9. The efficiency of reading around learned backgrounds

    NASA Astrophysics Data System (ADS)

    Eckstein, Miguel P.; Pham, Binh T.; Abbey, Craig K.; Zhang, Yani

    2006-03-01

    Most metrics of medical image quality typically treat all variability components of the background as a Gaussian noise process. This includes task based model observers (non-prewhitening matched filter without and with an eye filter, NPW and NPWE; Hotelling and Channelized Hotelling) as well as Fourier metrics of medical image quality based on the noise power spectra. However, many investigators have observed that unlike many of the models/metrics, physicians often can discount signal-looking structures that are part of the normal anatomic background. This process has been referred to as reading around the background or noise. The purpose of this paper is to develop an experimental framework to systematically study the ability of human observers to read around learned backgrounds and compare their ability to that of an optimal ideal observer which has knowledge of the background. We measured human localization performance of one of twelve targets in the presence of a fixed background consisting of randomly placed Gaussians with random contrasts and sizes, and white noise. Performance was compared to a condition in which the test images contained only white noise but with higher contrast. Human performance was compared to standard model observers that treat the background as a Gaussian noise process (NPW, NPWE and Hotelling), a Fourier-based prewhitening matched filter, and an ideal observer. The Hotelling, NPW, NPWE models as well as the Fourier-based prewhitening matched filter predicted higher performance for the white noise test images than the background plus white noise. In contrast, ideal and human performance was higher for the background plus white noise condition. Furthermore, human performance exceeded that of the NPW, NPWE and Hotelling models and reached an efficiency of 19% relative to the ideal observer. Our results demonstrate that for some types of images human signal localization performance is consistent with use of knowledge about the high order

  10. Low-background Gamma Spectroscopy at Sanford Underground Laboratory

    NASA Astrophysics Data System (ADS)

    Chiller, Christopher; Alanson, Angela; Mei, Dongming

    2014-03-01

    Rare-event physics experiments require the use of material with unprecedented radio-purity. Low background counting assay capabilities and detectors are critical for determining the sensitivity of the planned ultra-low background experiments. A low-background counting, LBC, facility has been built at the 4850-Level Davis Campus of the Sanford Underground Research Facility to perform screening of material and detector parts. Like many rare event physics experiments, our LBC uses lead shielding to mitigate background radiation. Corrosion of lead brick shielding in subterranean installations creates radon plate-out potential as well as human risks of ingestible or respirable lead compounds. Our LBC facilities employ an exposed lead shield requiring clean smooth surfaces. A cleaning process of low-activity silica sand blasting and borated paraffin hot coating preservation was employed to guard against corrosion due to chemical and biological exposures. The resulting lead shield maintains low background contribution integrity while fully encapsulating the lead surface. We report the performance of the current LBC and a plan to develop a large germanium well detector for PMT screening. Support provided by Sd governors research center-CUBED, NSF PHY-0758120 and Sanford Lab.

  11. Ultra-low background measurements of decayed aerosol filters.

    PubMed

    Aalseth, Craig; Andreotti, Erica; Arnold, Dirk; Cabeza, Joan-Albert Sanchez; Degering, Detlev; Giuliani, Andrea; de Orduña, Raquel Gonzales; Gurriaran, Rodolfo; Hult, Mikael; Keillor, Martin; Laubenstein, Matthias; le Petit, Gilbert; Margineanu, Romul Mircea; Matthews, Murray; Miley, Harry; Osvath, Iolanda; Pellicciari, Monica; Plastino, Wolfango; Simgen, Hardy; Weber, Marc; Werzi, Robert

    Aerosol samples collected on filter media were analyzed using HPGe detectors employing varying background-reduction techniques in order to experimentally evaluate the opportunity to apply ultra-low background measurement methods to samples collected, for instance, by the Comprehensive Test Ban Treaty International Monitoring System (IMS). In this way, realistic estimates of the impact of low-background methodology on the sensitivity obtained in systems such as the IMS were assessed. The current detectability requirement of stations in the IMS is 30 μBq/m(3) of air for (140)Ba, which would imply ~10(6) fissions per daily sample. Importantly, this is for a fresh aerosol filter. One week of decay reduces the intrinsic background from radon daughters in the sample allowing much higher sensitivity measurement of relevant isotopes, including (131)I. An experiment was conducted in which decayed filter samples were measured at a variety of underground locations using Ultra-Low Background (ULB) gamma spectroscopy technology. The impacts of the decay and ULB are discussed.

  12. Background Noise Contributes to Organic Solvent Induced Brain Dysfunction

    PubMed Central

    Guthrie, O'neil W.; Wong, Brian A.; McInturf, Shawn M.; Reboulet, James E.; Ortiz, Pedro A.; Mattie, David R.

    2016-01-01

    Occupational exposure to complex blends of organic solvents is believed to alter brain functions among workers. However, work environments that contain organic solvents are also polluted with background noise which raises the issue of whether or not the noise contributed to brain alterations. The purpose of the current study was to determine whether or not repeated exposure to low intensity noise with and without exposure to a complex blend of organic solvents would alter brain activity. Female Fischer344 rats served as subjects in these experiments. Asynchronous volume conductance between the midbrain and cortex was evaluated with a slow vertex recording technique. Subtoxic solvent exposure, by itself, had no statistically significant effects. However, background noise significantly suppressed brain activity and this suppression was exacerbated with solvent exposure. Furthermore, combined exposure produced significantly slow neurotransmission. These abnormal neurophysiologic findings occurred in the absence of hearing loss and detectable damage to sensory cells. The observations from the current experiment raise concern for all occupations where workers are repeatedly exposed to background noise or noise combined with organic solvents. Noise levels and solvent concentrations that are currently considered safe may not actually be safe and existing safety regulations have failed to recognize the neurotoxic potential of combined exposures. PMID:26885406

  13. Measurement of Acceptable Noise Level with Background Music.

    PubMed

    Ahn, Hyun-Jung; Bahng, Junghwa; Lee, Jae Hee

    2015-09-01

    Acceptable noise level (ANL) is a measure of the maximum background noise level (BNL) that a person is willing to tolerate while following a target story. Although researchers have used various sources of target sound in ANL measures, a limited type of background noise has been used. Extending the previous study of Gordon-Hickey & Moore (2007), the current study determined the effect of music genre and tempo on ANLs as possible factors affecting ANLs. We also investigated the relationships between individual ANLs and the familiarity of music samples and between music ANLs and subjective preference. Forty-one participants were seperated into two groups according to their ANLs, 29 low-ANL listeners and 12 high-ANL listeners. Using Korean ANL material, the individual ANLs were measured based on the listeners' most comfortable listening level and BNL. The ANLs were measured in six conditions, with different music tempo (fast, slow) and genre (K-pop, pop, classical) in a counterbalanced order. Overall, ANLs did not differ by the tempo of background music, but music genre significantly affected individual ANLs. We observed relatively higher ANLs with K-pop music and relatively lower ANLs with classical music. This tendency was similar in both low-ANL and high-ANL groups. However, the subjective ratings of music familiarity and preference affected ANLs differently for low-ANL and high-ANL groups. In contrast to the low-ANL listeners, the ANLs of the high-ANL listeners were significantly affected by music familiarity and preference. The genre of background music affected ANLs obtained using background music. The degree of music familiarity and preference appears to be associated with individual susceptibility to background music only for listeners who are greatly annoyed by background noise (high-ANL listeners).

  14. Effect of background electrolytes on gypsum dissolution

    NASA Astrophysics Data System (ADS)

    Burgos-Cara, Alejandro; Putnis, Christine; Ruiz-Agudo, Encarnacion

    2015-04-01

    Knowledge of the dissolution behaviour of gypsum (CaSO4· 2H2O) in aqueous solutions is of primary importance in many natural and technological processes (Pachon-Rodriguez and Colombani, 2007), including the weathering of rocks and gypsum karst formations, deformation of gypsum-bearing rocks, the quality of drinking water, amelioration of soil acidity, scale formation in the oil and gas industry or measurement of water motion in oceanography. Specific ions in aqueous solutions can play important but very different roles on mineral dissolution. For example, the dissolution rates and the morphology of dissolution features may be considerably modified by the presence of the foreign ions in the solution, which adsorb at the surface and hinder the detachment of the ions building the crystal. Dissolution processes in the aqueous environment are closely related to the rearrangement of water molecules around solute ions and the interaction between the solvent molecules themselves. The rearrangement of water molecules with respect to solute species has been recognized as the main kinetic barrier for crystal dissolution in many systems (Davis, 2000; De Yoreo and Dove 2004; Wasylenki et al. 2005). Current research suggest that the control that electrolytes exert on water structure is limited to the local environment surrounding the ions and is not related to long-range electric fields emanating from the ions but results from effects associated with the hydration shell(s) of the ions (Collins et al. 2007) and the ions' capacity to break or structure water (i.e. chaotropic and kosmotropic ions, respectively). These effects will ultimately affect the kinetics of crystal dissolution, and could be correlated with the water affinity of the respective background ions following a trend known as the lyotropic or Hofmeister series (Kunz et al. 2004; Dove and Craven, 2005). In situ macroscopic and Atomic Force Microscopy (AFM) flow-through dissolution experiments were conducted at a

  15. Extragalactic background light measurements and applications

    PubMed Central

    Cooray, Asantha

    2016-01-01

    This review covers the measurements related to the extragalactic background light intensity from γ-rays to radio in the electromagnetic spectrum over 20 decades in wavelength. The cosmic microwave background (CMB) remains the best measured spectrum with an accuracy better than 1%. The measurements related to the cosmic optical background (COB), centred at 1 μm, are impacted by the large zodiacal light associated with interplanetary dust in the inner Solar System. The best measurements of COB come from an indirect technique involving γ-ray spectra of bright blazars with an absorption feature resulting from pair-production off of COB photons. The cosmic infrared background (CIB) peaking at around 100 μm established an energetically important background with an intensity comparable to the optical background. This discovery paved the way for large aperture far-infrared and sub-millimetre observations resulting in the discovery of dusty, starbursting galaxies. Their role in galaxy formation and evolution remains an active area of research in modern-day astrophysics. The extreme UV (EUV) background remains mostly unexplored and will be a challenge to measure due to the high Galactic background and absorption of extragalactic photons by the intergalactic medium at these EUV/soft X-ray energies. We also summarize our understanding of the spatial anisotropies and angular power spectra of intensity fluctuations. We motivate a precise direct measurement of the COB between 0.1 and 5 μm using a small aperture telescope observing either from the outer Solar System, at distances of 5 AU or more, or out of the ecliptic plane. Other future applications include improving our understanding of the background at TeV energies and spectral distortions of CMB and CIB. PMID:27069645

  16. Extragalactic background light measurements and applications.

    PubMed

    Cooray, Asantha

    2016-03-01

    This review covers the measurements related to the extragalactic background light intensity from γ-rays to radio in the electromagnetic spectrum over 20 decades in wavelength. The cosmic microwave background (CMB) remains the best measured spectrum with an accuracy better than 1%. The measurements related to the cosmic optical background (COB), centred at 1 μm, are impacted by the large zodiacal light associated with interplanetary dust in the inner Solar System. The best measurements of COB come from an indirect technique involving γ-ray spectra of bright blazars with an absorption feature resulting from pair-production off of COB photons. The cosmic infrared background (CIB) peaking at around 100 μm established an energetically important background with an intensity comparable to the optical background. This discovery paved the way for large aperture far-infrared and sub-millimetre observations resulting in the discovery of dusty, starbursting galaxies. Their role in galaxy formation and evolution remains an active area of research in modern-day astrophysics. The extreme UV (EUV) background remains mostly unexplored and will be a challenge to measure due to the high Galactic background and absorption of extragalactic photons by the intergalactic medium at these EUV/soft X-ray energies. We also summarize our understanding of the spatial anisotropies and angular power spectra of intensity fluctuations. We motivate a precise direct measurement of the COB between 0.1 and 5 μm using a small aperture telescope observing either from the outer Solar System, at distances of 5 AU or more, or out of the ecliptic plane. Other future applications include improving our understanding of the background at TeV energies and spectral distortions of CMB and CIB.

  17. Cosmic Coincidences: Investigations for Neutron Background Suppression

    PubMed Central

    Heimbach, Craig R.

    2007-01-01

    Two experimental investigations were made in order to reduce background counts in neutron detectors. Each investigation relied upon the fact that neutron background is largely due to cosmic ray interactions with the air and ground. The first attempt was to look at neutron arrival times. Neutron events close in time were taken to have been of a common origin due to cosmic rays. The second investigation was similar, but based on coincident neutron/muon events. The investigations showed only a small effect, not practical for the suppression of neutron background. PMID:27110457

  18. Cosmic Coincidences: Investigations for Neutron Background Suppression.

    PubMed

    Heimbach, Craig R

    2007-01-01

    Two experimental investigations were made in order to reduce background counts in neutron detectors. Each investigation relied upon the fact that neutron background is largely due to cosmic ray interactions with the air and ground. The first attempt was to look at neutron arrival times. Neutron events close in time were taken to have been of a common origin due to cosmic rays. The second investigation was similar, but based on coincident neutron/muon events. The investigations showed only a small effect, not practical for the suppression of neutron background.

  19. 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

  20. Exploiting background knowledge in automated discovery

    SciTech Connect

    Aronis, J.M.; Buchanan, B.G.; Provost, F.J.

    1996-12-31

    Prior work in automated scientific discovery has been successful in finding patterns in data, given that a reasonably small set of mostly relevant features is specified. The work described in this paper places data in the context of large bodies of background knowledge. Specifically, data items are connected to multiple databases of background knowledge represented as inheritance networks. The system has made a practical impact on botanical toxicology research, which required linking examples of cases of plant exposures to databases of botanical, geographical, and climate background knowledge.

  1. 16 CFR 1406.2 - Background.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... APPLIANCES-NOTIFICATION OF PERFORMANCE AND TECHNICAL DATA § 1406.2 Background. (a) Fire data analyzed by the... mechanical defects or excessive deposits of flammable creosote. (b) After considering the available data...

  2. Activating Background Knowledge in Reading Comprehension Assessment.

    ERIC Educational Resources Information Center

    Rowe, Deborah Wells; Rayford, Lawrence

    1987-01-01

    Indicates that a broad age range of students can use some purpose questions as cues to activate background knowledge. Suggest topic familiarity, amount of information presented, and the presence of genre clues as text features affecting schema activation. (NKA)

  3. High-energy radiation background in space

    NASA Astrophysics Data System (ADS)

    Rester, A. C., Jr.; Trombka, J. I.

    The radiation environment of near-earth space and its effects on biological and hardware systems are examined in reviews and reports. Sections are devoted to particle interactions and propagation, data bases, instrument background and dosimetry, detectors and experimental progress, biological effects, and future needs and strategies. Particular attention is given to angular distributions and spectra of geomagnetically trapped protons in LEO, bremsstrahlung production by electrons, nucleon-interaction data bases for background estimates, instrumental and atmospheric background lines observed by the SMM gamma-ray spectrometer, the GRAD high-altitude balloon flight over Antarctica, space protons and brain tumors, a new radioprotective antioxidative agent, LEO radiation measurements on the Space Station, and particle-background effects on the Hubble Space Telescope and the Lyman FUV Spectroscopic Explorer.

  4. 32 CFR 770.42 - Background.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ACCESS TO PARTICULAR INSTALLATIONS Base Entry Regulations for Naval Submarine Base New London, Groton, Connecticut § 770.42 Background. Naval Submarine Base New London maintains and operates facilities to...

  5. The cosmic X-ray background

    NASA Technical Reports Server (NTRS)

    Boldt, Elihu A.

    1987-01-01

    The present knowledge about the overall spectrum of the isotropic extragalactic background of electromagnetic radiation is summarized. The role of the HEAO program is discussed. Spectral measurements from HEAO are examined.

  6. 32 CFR 770.37 - Background.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ACCESS TO PARTICULAR INSTALLATIONS Entry Regulations for Naval Installations and Property in Puerto Rico § 770.37 Background. In accordance with 32 CFR 765.4, Naval installations and properties in Puerto Rico...

  7. 32 CFR 770.37 - Background.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ACCESS TO PARTICULAR INSTALLATIONS Entry Regulations for Naval Installations and Property in Puerto Rico § 770.37 Background. In accordance with 32 CFR 765.4, Naval installations and properties in Puerto Rico...

  8. Background music: effects on attention performance.

    PubMed

    Shih, Yi-Nuo; Huang, Rong-Hwa; Chiang, Hsin-Yu

    2012-01-01

    Previous studies indicate that noise may affect worker attention. However, some background music in the work environment can increase worker satisfaction and productivity. This study compared how music with, and without, lyrics affects human attention. One hundred and two participants, aged 20-24 years, were recruited into this study. Fifty-six males and 46 females participated in this study. Background music with, and without lyrics, was tested for effects on listener concentration in attention testing using a randomized controlled trial (RCT) study. The comparison results revealed that background music with lyrics had significant negative effects on concentration and attention. The findings suggest that, if background music is played in the work environment, music without lyrics is preferable because songs with lyrics are likely to reduce worker attention and performance.

  9. 38 CFR 200.2 - Background.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... permit high standards of living and a wide sharing of life's amenities; and (6) Enhance the quality of... NATIONAL ENVIRONMENTAL POLICY ACT § 200.2 Background. (a) The NEPA and the Council on Environmental...

  10. High-energy radiation background in space

    NASA Technical Reports Server (NTRS)

    Rester, A. C., Jr. (Editor); Trombka, J. I. (Editor)

    1989-01-01

    The radiation environment of near-earth space and its effects on biological and hardware systems are examined in reviews and reports. Sections are devoted to particle interactions and propagation, data bases, instrument background and dosimetry, detectors and experimental progress, biological effects, and future needs and strategies. Particular attention is given to angular distributions and spectra of geomagnetically trapped protons in LEO, bremsstrahlung production by electrons, nucleon-interaction data bases for background estimates, instrumental and atmospheric background lines observed by the SMM gamma-ray spectrometer, the GRAD high-altitude balloon flight over Antarctica, space protons and brain tumors, a new radioprotective antioxidative agent, LEO radiation measurements on the Space Station, and particle-background effects on the Hubble Space Telescope and the Lyman FUV Spectroscopic Explorer.

  11. Physics of the Cosmic Microwave Background Radiation

    NASA Astrophysics Data System (ADS)

    Wands, David; Piattella, Oliver F.; Casarini, Luciano

    The cosmic microwave background (CMB) radiation provides a remarkable window onto the early universe, revealing its composition and structure. In these lectures we review and discuss the physics underlying the main features of the CMB.

  12. Charged Hadron Properties in Background Electric Fields

    SciTech Connect

    William Detmold, Brian C. Tiburzi, Andre Walker-Loud

    2010-02-01

    We report on a lattice calculation demonstrating a novel new method to extract the electric polarizability of charged pseudo-scalar mesons by analyzing two point correlation functions computed in classical background electric fields.

  13. Military Retirement: Background and Recent Developments

    DTIC Science & Technology

    2014-01-27

    Military Retirement: Background and Recent Developments David F. Burrelli Specialist in Military Manpower Policy Barbara Salazar Torreon...COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Military Retirement: Background and Recent Developments 5a. CONTRACT NUMBER 5b. GRANT NUMBER...Recent Developments Congressional Research Service Summary The military retirement system is a noncontributory, defined benefit system that has

  14. BKGE: Fermi-LAT Background Estimator

    NASA Astrophysics Data System (ADS)

    Vasileiou, Vlasios

    2014-11-01

    The Fermi-LAT Background Estimator (BKGE) is a publicly available open-source tool that can estimate the expected background of the Fermi-LAT for any observational conguration and duration. It produces results in the form of text files, ROOT files, gtlike source-model files (for LAT maximum likelihood analyses), and PHA I/II FITS files (for RMFit/XSpec spectral fitting analyses). Its core is written in C++ and its user interface in Python.

  15. Supermembrane actions for Gaiotto-Maldacena backgrounds

    NASA Astrophysics Data System (ADS)

    Stefański, Bogdan

    2014-06-01

    We write down the supermembrane actions for M-theory backgrounds dual to general N=2 four-dimensional superconformal field theories. The actions are given to all orders in fermions and are in a particular κ-gauge. When an extra U(1) isometry is present, our actions reduce to κ-gauge fixed Green-Schwarz actions for the corresponding Type IIA backgrounds.

  16. Estimating radiological background using imaging spectroscopy

    SciTech Connect

    Bernacki, Bruce E.; Schweppe, John E.; Stave, Sean C.; Jordan, David V.; Kulisek, Jonathan A.; Stewart, Trevor N.; Seifert, Carolyn E.

    2014-06-13

    Optical imaging spectroscopy is investigated as a method to estimate radiological background by spectral identification of soils, sediments, rocks, minerals and building materials derived from natural materials and assigning tabulated radiological emission values to these materials. Radiological airborne surveys are undertaken by local, state and federal agencies to identify the presence of radiological materials out of regulatory compliance. Detection performance in such surveys is determined by (among other factors) the uncertainty in the radiation background; increased knowledge of the expected radiation background will improve the ability to detect low-activity radiological materials. Radiological background due to naturally occurring radiological materials (NORM) can be estimated by reference to previous survey results, use of global 40K, 238U, and 232Th (KUT) values, reference to existing USGS radiation background maps, or by a moving average of the data as it is acquired. Each of these methods has its drawbacks: previous survey results may not include recent changes, the global average provides only a zero-order estimate, the USGS background radiation map resolutions are coarse and are accurate only to 1 km – 25 km sampling intervals depending on locale, and a moving average may essentially low pass filter the data to obscure small changes in radiation counts. Imaging spectroscopy from airborne or spaceborne platforms can offer higher resolution identification of materials and background, as well as provide imaging context information. AVIRIS hyperspectral image data is analyzed using commercial exploitation software to determine the usefulness of imaging spectroscopy to identify qualitative radiological background emissions when compared to airborne radiological survey data.

  17. The pregalactic cosmic gravitational wave background

    NASA Technical Reports Server (NTRS)

    Matzner, Richard A.

    1989-01-01

    An outline is given that estimates the expected gravitational wave background, based on plausible pregalactic sources. Some cosmologically significant limits can be put on incoherent gravitational wave background arising from pregalactic cosmic evolution. The spectral region of cosmically generated and cosmically limited radiation is, at long periods, P greater than 1 year, in contrast to more recent cosmological sources, which have P approx. 10 to 10(exp -3).

  18. Low background screening capability in the UK

    SciTech Connect

    Ghag, Chamkaur

    2015-08-17

    Low background rare event searches in underground laboratories seeking observation of direct dark matter interactions or neutrino-less double beta decay have the potential to profoundly advance our understanding of the physical universe. Successful results from these experiments depend critically on construction from extremely radiologically clean materials and accurate knowledge of subsequent low levels of expected background. The experiments must conduct comprehensive screening campaigns to reduce radioactivity from detector components, and these measurements also inform detailed characterisation and quantification of background sources and their impact, necessary to assign statistical significance to any potential discovery. To provide requisite sensitivity for material screening and characterisation in the UK to support our rare event search activities, we have re-developed our infrastructure to add ultra-low background capability across a range of complementary techniques that collectively allow complete radioactivity measurements. Ultra-low background HPGe and BEGe detectors have been installed at the Boulby Underground Laboratory, itself undergoing substantial facility re-furbishment, to provide high sensitivity gamma spectroscopy in particular for measuring the uranium and thorium decay series products. Dedicated low-activity mass spectrometry instrumentation has been developed at UCL for part per trillion level contaminant identification to complement underground screening with direct U and Th measurements, and meet throughput demands. Finally, radon emanation screening at UCL measures radon background inaccessible to gamma or mass spectrometry techniques. With this new capability the UK is delivering half of the radioactivity screening for the LZ dark matter search experiment.

  19. Modeling background intensity in DNA microarrays

    NASA Astrophysics Data System (ADS)

    Kroll, K. M.; Barkema, G. T.; Carlon, E.

    2008-06-01

    DNA microarrays are devices that are able, in principle, to detect and quantify the presence of specific nucleic acid sequences in complex biological mixtures. The measurement consists in detecting fluorescence signals from several spots on the microarray surface onto which different probe sequences are grafted. One of the problems of the data analysis is that the signal contains a noisy background component due to nonspecific binding. We present a physical model for background estimation in Affymetrix Genechips. It combines two different approaches. The first is based on the sequence composition, specifically its sequence-dependent hybridization affinity. The second is based on the strong correlation of intensities from locations which are the physical neighbors of a specific spot on the chip. Both effects are incorporated in a background estimator which contains 24 free parameters, fixed by minimization on a training data set. In all data analyzed the sequence-specific parameters, obtained by minimization, are found to strongly correlate with empirically determined stacking free energies for RNA-DNA hybridization in solution. Moreover, there is an overall agreement with experimental background data and we show that the physics-based model that we propose performs on average better than purely statistical approaches for background calculations. The model thus provides an interesting alternative method for background subtraction schemes in Affymetrix Genechips.

  20. Background simulations for the Large Area Detector onboard LOFT

    NASA Astrophysics Data System (ADS)

    Campana, Riccardo; Feroci, Marco; Del Monte, Ettore; Mineo, Teresa; Lund, Niels; Fraser, George W.

    2013-12-01

    The Large Observatory For X-ray Timing (LOFT), currently in an assessment phase in the framework the ESA M3 Cosmic Vision programme, is an innovative medium-class mission specifically designed to answer fundamental questions about the behaviour of matter, in the very strong gravitational and magnetic fields around compact objects and in supranuclear density conditions. Having an effective area of ˜10 m2 at 8 keV, LOFT will be able to measure with high sensitivity very fast variability in the X-ray fluxes and spectra. A good knowledge of the in-orbit background environment is essential to assess the scientific performance of the mission and optimize the design of its main instrument, the Large Area Detector (LAD). In this paper the results of an extensive Geant-4 simulation of the instrumentwillbe discussed, showing the main contributions to the background and the design solutions for its reduction and control. Our results show that the current LOFT/LAD design is expected to meet its scientific requirement of a background rate equivalent to 10 mCrab in 2‒30 keV, achieving about 5 mCrab in the most important 2-10 keV energy band. Moreover, simulations show an anticipated modulation of the background rate as small as 10 % over the orbital timescale. The intrinsic photonic origin of the largest background component also allows for an efficient modelling, supported by an in-flight active monitoring, allowing to predict systematic residuals significantly better than the requirement of 1 %, and actually meeting the 0.25 % science goal.

  1. The study of diffuse soft X-ray background

    NASA Astrophysics Data System (ADS)

    Gupta, Anjali

    The cosmic X-ray background was discovered at the dawn of the X-ray astronomy: during the first successful rocket flight launched to study the X-ray emission from the Moon, the presence of a residual diffuse emission was also "serendipitously" revealed. In the intervening decades, observations with improving angular and spectral resolution have enhanced our understanding of the components that make up this background. Above 1 keV, the emission is highly isotropic on large angular scales, has extragalactic origin, and about ~80 percent has been resolved into discrete sources (Mushotzky et al. 2000, Hasinger et al. 1998). Our current interpretation of the diffuse X-ray emission below 1 keV uses a combination of 5 components, solar wind charge exchange, Local Bubble, Galactic halo, intergalactic gas, and unresolved point sources. Resolving the different components is made particularly difficult by the similar spectral emission of most components, X-ray lines of heavily ionized metals, which are poorly resolved by the energy resolution of CCD cameras onboard current X-ray satellites with typical observing times. The goal of this investigation is to assess the integral emission of the major components of the diffuse Soft X-Ray Background. In the first part of my project, I analyzed the shadow observations performed with XMM-Newton and Suzaku X-ray observatories. Shadow observations offer a tool to separate the fore ground component, due to the Local Bubble and, possibly, charge exchange within the solar system, from the background component, due primarily to the Galactic Halo and unidentified point sources. In the second part of my project, I studied the contribution of unresolved point sources and intergalactic medium to the diffuse Soft X-ray Background.

  2. Stochastic gravitational wave background from light cosmic strings

    SciTech Connect

    DePies, Matthew R.; Hogan, Craig J.

    2007-06-15

    Spectra of the stochastic gravitational wave backgrounds from cosmic strings are calculated and compared with present and future experimental limits. Motivated by theoretical expectations of light cosmic strings in superstring cosmology, improvements in experimental sensitivity, and recent demonstrations of large, stable loop formation from a primordial network, this study explores a new range of string parameters with masses lighter than previously investigated. A standard 'one-scale' model for string loop formation is assumed. Background spectra are calculated numerically for dimensionless string tensions G{mu}/c{sup 2} between 10{sup -7} and 10{sup -18}, and initial loop sizes as a fraction of the Hubble radius {alpha} from 0.1 to 10{sup -6}. The spectra show a low frequency power-law tail, a broad spectral peak due to loops decaying at the present epoch (including frequencies higher than their fundamental mode, and radiation associated with cusps), and a flat (constant energy density) spectrum at high frequencies due to radiation from loops that decayed during the radiation-dominated era. The string spectrum is distinctive and unlike any other known source. The peak of the spectrum for light strings appears at high frequencies, significantly affecting predicted signals. The spectra of the cosmic string backgrounds are compared with current millisecond pulsar limits and Laser Interferometer Space Antenna (LISA) sensitivity curves. For models with large stable loops ({alpha}=0.1), current pulsar-timing limits exclude G{mu}/c{sup 2}>10{sup -9}, a much tighter limit on string tension than achievable with other techniques, and within the range of current models based on brane inflation. LISA may detect a background from strings as light as G{mu}/c{sup 2}{approx_equal}10{sup -16}, corresponding to field theory strings formed at roughly 10{sup 11} GeV.

  3. A review on natural background radiation

    PubMed Central

    Shahbazi-Gahrouei, Daryoush; Gholami, Mehrdad; Setayandeh, Samaneh

    2013-01-01

    The world is naturally radioactive and approximately 82% of human-absorbed radiation doses, which are out of control, arise from natural sources such as cosmic, terrestrial, and exposure from inhalation or intake radiation sources. In recent years, several international studies have been carried out, which have reported different values regarding the effect of background radiation on human health. Gamma radiation emitted from natural sources (background radiation) is largely due to primordial radionuclides, mainly 232Th and 238U series, and their decay products, as well as 40K, which exist at trace levels in the earth's crust. Their concentrations in soil, sands, and rocks depend on the local geology of each region in the world. Naturally occurring radioactive materials generally contain terrestrial-origin radionuclides, left over since the creation of the earth. In addition, the existence of some springs and quarries increases the dose rate of background radiation in some regions that are known as high level background radiation regions. The type of building materials used in houses can also affect the dose rate of background radiations. The present review article was carried out to consider all of the natural radiations, including cosmic, terrestrial, and food radiation. PMID:24223380

  4. On conformal higher spins in curved background

    NASA Astrophysics Data System (ADS)

    Grigoriev, M.; Tseytlin, A. A.

    2017-03-01

    We address the question of how to represent an interacting action for a tower of conformal higher spin fields in a form covariant with respect to a background metric. We use the background metric to define the star product which plays a central role in the definition of the corresponding gauge transformations. By analogy with the kinetic term in the 4-derivative Weyl gravity action expanded near an on-shell background one expects that the kinetic term in such an action should be gauge-invariant in a Bach-flat metric. We demonstrate this fact to first order in expansion in powers of the curvature of the background metric. This generalizes the result of arXiv:1404.7452 for spin 3 case to all conformal higher spins. We also comment on a possibility of extending this claim to terms quadratic in the curvature and discuss the appearance of background-dependent mixing terms in the quadratic part of the conformal higher spin action.

  5. Measurements of the cosmic background radiation

    NASA Technical Reports Server (NTRS)

    Weiss, R.

    1980-01-01

    Measurements of the attributes of the 2.7-K microwave background radiation (CBR) are reviewed, with emphasis on the analytic phase of CBR studies. Methods for the direct measurement of the CBR spectrum are discussed; attention is given to receivers, antennas, absolute receiver calibration, atmospheric emission and absorption, the galactic background contribution, the analysis of LF measurements, and recent HF observations of the CBR spectrum. Measurements of the large-angular-scale intensity distribution of the CBR (the most convincing evidence that the radiation is of cosmological origin) are examined, along with limits on the linear polarization of the CBR. A description is given of the NASA-sponsored Cosmic Background Explorer (COBE) satellite mission. The results of the COBE mission will be a set of sky maps showing, in the wave number range from 1 to 10,000 kaysers, the galactic background radiation due to synchrotron emission from galactic cosmic rays, to diffuse thermal emission from H II regions, and to diffuse thermal emission from interstellar and interplanetary dust, as well as a residue consisting of the CBR and whatever other cosmological background might exist.

  6. Measurements of the cosmic background radiation

    SciTech Connect

    Weiss, R.

    1980-01-01

    Measurements of the attributes of the 2.7-K microwave background radiation (CBR) are reviewed, with emphasis on the analytic phase of CBR studies. Methods for the direct measurement of the CBR spectrum are discussed. Attention is given to receivers, antennas, absolute receiver calibration, atmospheric emission and absorption, the galactic background contribution, the analysis of LF measurements, and recent HF observations of the CBR spectrum. Measurements of the large-angular-scale intensity distribution of the CBR (the most convincing evidence that the radiation is of cosmological origin) are examined, along with limits on the linear polarization of the CBR. A description is given of the NASA-sponsored Cosmic Background Explorer (COBE) satellite mission. The results of the COBE mission will be a set of sky maps showing, in the wave number range from 1 to 10,000 kaysers, the galactic background radiation due to synchrotron emission from galactic cosmic rays, to diffuse thermal emission from H II regions, and to diffuse thermal emission from interstellar and interplanetary dust, as well as a residue consisting of the CBR and whatever other cosmological background might exist.

  7. Integrated background monitoring in the USSR.

    PubMed

    Izrael, Y A; Rovinsky, F Y

    1988-01-01

    The whole biosphere of the Earth is faced with an increasing anthropogenic pressure. Mankind uses natural resources for its physical and spiritual demands so widely that undesirable effects appear not only in separate regions but embrace the whole biosphere as well. As a rule, such processes develop slowly. They have an irreversible character and to avoid them, preventive decisions are needed. For that purpose, comprehensive and systematic information on the state of the biosphere is needed.The integrated background monitoring system has been implemented and is in operation in the USSR. Structurally, the integrated background monitoring system is divided into three groups: background stations on land; background stations on fresh water; and background stations on inland and periphery seas.All of the data received from these stations are analyzed and correlated at the Natural Environment and Climate Monitoring Laboratory of the USSR State Committee for Hydrometeorology and Control of the Natural Environment, the USSR Academy of Sciences, and in other scientific institutes of the State Committee. The information serves for the assessment of the state of the environment, prediction of anthropogenic effects, and for evaluation of the measures taken to prevent pollution of the biosphere at national and international levels.The information is shared in a wide international exchange within the framework of several international organizations (UNEP, WMO, UNESCO, ECE, CMEA, and others) and of the bilateral agreements on cooperation in the field of environmental protection (USA, France, Sweden, FRG, CMEA Member Countries).

  8. Modeled summer background concentration nutrients and ...

    EPA Pesticide Factsheets

    We used regression models to predict background concentration of four water quality indictors: total nitrogen (N), total phosphorus (P), chloride, and total suspended solids (TSS), in the mid-continent (USA) great rivers, the Upper Mississippi, the Lower Missouri, and the Ohio. From best-model linear regressions of water quality indicators with land use and other stressor variables, we determined the concentration of the indicators when the land use and stressor variables were all set to zero the y-intercept. Except for total P on the Upper Mississippi River and chloride on the Ohio River, we were able to predict background concentration from significant regression models. In every model with more than one predictor variable, the model included at least one variable representing agricultural land use and one variable representing development. Predicted background concentration of total N was the same on the Upper Mississippi and Lower Missouri rivers (350 ug l-1), which was much lower than a published eutrophication threshold and percentile-based thresholds (25th percentile of concentration at all sites in the population) but was similar to a threshold derived from the response of sestonic chlorophyll a to great river total N concentration. Background concentration of total P on the Lower Missouri (53 ug l-1) was also lower than published and percentile-based thresholds. Background TSS concentration was higher on the Lower Missouri (30 mg l-1) than the other ri

  9. Modeling background radiation in Southern Nevada.

    PubMed

    Haber, Daniel A; Burnley, Pamela C; Adcock, Christopher T; Malchow, Russell L; Marsac, Kara E; Hausrath, Elisabeth M

    2017-02-06

    Aerial gamma ray surveys are an important tool for national security, scientific, and industrial interests in determining locations of both anthropogenic and natural sources of radioactivity. There is a relationship between radioactivity and geology and in the past this relationship has been used to predict geology from an aerial survey. The purpose of this project is to develop a method to predict the radiologic exposure rate of the geologic materials by creating a high resolution background model. The intention is for this method to be used in an emergency response scenario where the background radiation environment is unknown. Two study areas in Southern Nevada have been modeled using geologic data, images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), geochemical data, and pre-existing low resolution aerial surveys from the National Uranium Resource Evaluation (NURE) Survey. Using these data, geospatial areas that are homogenous in terms of K, U, and Th, referred to as background radiation units, are defined and the gamma ray exposure rate is predicted. The prediction is compared to data collected via detailed aerial survey by the Department of Energy's Remote Sensing Lab - Nellis, allowing for the refinement of the technique. By using geologic units to define radiation background units of exposed bedrock and ASTER visualizations to subdivide and define radiation background units within alluvium, successful models have been produced for Government Wash, north of Lake Mead, and for the western shore of Lake Mohave, east of Searchlight, NV.

  10. Stellar background EUV as a source of Titan's nightside ionosphere

    NASA Astrophysics Data System (ADS)

    Moore, Luke; O'Donoghue, James; Mendillo, Michael

    2016-10-01

    Stellar background EUV photons can ionize molecular species in planetary atmospheres, and in fact are the dominant source of the terrestrial E region at night. Recent modeling efforts based on in situ measurements of Titan's upper atmosphere by the Cassini spacecraft have proposed a range of possible sources of Titan's nightside ionosphere, including: persistence of ions created on the dayside, transport of dayside ions, and ionization due to precipitation of energetic particles from Saturn's magnetosphere. All of these sources are likely present, but the additional source of ionization due to stellar background EUV - which is also present - has thus far been neglected. Consequently, the currently modeled sources of nightside ionization have likely been overestimated in order to match observed densities. Moreover, there are uncertainties associated with each of the currently treated sources - such as complicated photochemistry, or precipitating energy fluxes and energies - that may be reduced by inclusion of this additional source of ionization.We present calculated ion production rates at Titan based on an updated estimate of the stellar background EUV radiation field as well as preliminary 1D ionospheric modeling that includes a representative set of Titan photochemical reactions.

  11. Pythia Jet Finding Study with Trento Backgrounds

    SciTech Connect

    Simpson, Joseph; Soltz, Ron

    2016-06-22

    We present results applying the Pythia SlowJet Finder to Pythia generated QCD and QED hard processes in the presence of simulated heavy ion backgrounds. The hard process events are generated with Pythia version 8.219 for √sNN=200 GeV proton-proton collisions and the backgrounds are generated by the Reduced Thickness Event-by-event Nuclear Topology model TRENTo for Au-Au collisions with a nucleon-nucleon cross-section of 4.23 fm2. The TRENTo model is used to calculate the initial entropy and ellipticity from which the total charged particle multiplicity and elliptic ow are determined. We report results in the form of event displays, total pT distributions, and fragmentation distributions for SlowJet applied to Pythia events with and without the simulated heavy ion backgrounds.

  12. 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

  13. 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.

  14. X-Ray Background Survey Spectrometer (XBSS)

    NASA Technical Reports Server (NTRS)

    Sanders, W. T. (Principal Investigator); Paulos, R. J.

    1996-01-01

    The objective of this investigation was to perform a spectral survey of the low energy diffuse X-ray background using the X-ray Background Survey Spectrometer (XBSS) on board the Space Station Freedom (SSF). XBSS obtains spectra of the X-ray diffuse background in the 11-24 A and 44-84 A wavelength intervals over the entire sky with 15 deg spatial resolution. These X-rays are almost certainly from a very hot (10(exp 6) K) component of the interstellar medium that is contained in regions occupying a large fraction of the interstellar volume near the Sun. Astrophysical plasmas near 10(exp 6) K are rich in emission lines, and the relative strengths of these lines, besides providing information about the physical conditions of the emitting gas, also provide information about its history and heating mechanisms.

  15. Background modeling for the GERDA experiment

    SciTech Connect

    Becerici-Schmidt, N.; Collaboration: GERDA Collaboration

    2013-08-08

    The neutrinoless double beta (0νββ) decay experiment GERDA at the LNGS of INFN has started physics data taking in November 2011. This paper presents an analysis aimed at understanding and modeling the observed background energy spectrum, which plays an essential role in searches for a rare signal like 0νββ decay. A very promising preliminary model has been obtained, with the systematic uncertainties still under study. Important information can be deduced from the model such as the expected background and its decomposition in the signal region. According to the model the main background contributions around Q{sub ββ} come from {sup 214}Bi, {sup 228}Th, {sup 42}K, {sup 60}Co and α emitting isotopes in the {sup 226}Ra decay chain, with a fraction depending on the assumed source positions.

  16. Enhancements to the MCNP6 background source

    DOE PAGES

    McMath, Garrett E.; McKinney, Gregg W.

    2015-10-19

    The particle transport code MCNP has been used to produce a background radiation data file on a worldwide grid that can easily be sampled as a source in the code. Location-dependent cosmic showers were modeled by Monte Carlo methods to produce the resulting neutron and photon background flux at 2054 locations around Earth. An improved galactic-cosmic-ray feature was used to model the source term as well as data from multiple sources to model the transport environment through atmosphere, soil, and seawater. A new elevation scaling feature was also added to the code to increase the accuracy of the cosmic neutronmore » background for user locations with off-grid elevations. Furthermore, benchmarking has shown the neutron integral flux values to be within experimental error.« less

  17. Enhancements to the MCNP6 background source

    SciTech Connect

    McMath, Garrett E.; McKinney, Gregg W.

    2015-10-19

    The particle transport code MCNP has been used to produce a background radiation data file on a worldwide grid that can easily be sampled as a source in the code. Location-dependent cosmic showers were modeled by Monte Carlo methods to produce the resulting neutron and photon background flux at 2054 locations around Earth. An improved galactic-cosmic-ray feature was used to model the source term as well as data from multiple sources to model the transport environment through atmosphere, soil, and seawater. A new elevation scaling feature was also added to the code to increase the accuracy of the cosmic neutron background for user locations with off-grid elevations. Furthermore, benchmarking has shown the neutron integral flux values to be within experimental error.

  18. Background compensation for a radiation level monitor

    DOEpatents

    Keefe, D.J.

    1975-12-01

    Background compensation in a device such as a hand and foot monitor is provided by digital means using a scaler. With no radiation level test initiated, a scaler is down-counted from zero according to the background measured. With a radiation level test initiated, the scaler is up-counted from the previous down-count position according to the radiation emitted from the monitored object and an alarm is generated if, with the scaler having crossed zero in the positive going direction, a particular number is exceeded in a specific time period after initiation of the test. If the test is initiated while the scale is down-counting, the background count from the previous down- count stored in a memory is used as the initial starting point for the up-count.

  19. The homogeneity conjecture for supergravity backgrounds

    NASA Astrophysics Data System (ADS)

    Figueroa-O'Farrill, José Miguel

    2009-06-01

    These notes record three lectures given at the workshop "Higher symmetries in Physics", held at the Universidad Complutense de Madrid in November 2008. In them we explain how to construct a Lie (super)algebra associated to a spin manifold, perhaps with extra geometric data, and a notion of privileged spinors. The typical examples are supersymmetric supergravity backgrounds; although there are more classical instances of this construction. We focus on two results: the geometric constructions of compact real forms of the simple Lie algebras of type B4, F4 and E8 from S7, S8 and S15, respectively; and the construction of the Killing superalgebra of eleven-dimensional supergravity backgrounds. As an application of this latter construction we show that supersymmetric supergravity backgrounds with enough supersymmetry are necessarily locally homogeneous.

  20. Automated FingerPrint Background removal: FPB.

    PubMed

    Scalabrin, Simone; Morgante, Michele; Policriti, Alberto

    2009-04-30

    The construction of a whole-genome physical map has been an essential component of numerous genome projects initiated since the inception of the Human Genome Project. Its usefulness has been proved for whole-genome shotgun projects as a post-assembly validation and recently it has also been used in the assembly step to constrain on BACs positions. Fingerprinting is usually the method of choice for construction of physical maps. A clone fingerprint is composed of true peaks representing real fragments and background peaks, mainly composed of E. coli genomic DNA, partial digestions, star activity by-products, and machine background. High-throughput fingerprinting leads to the production of thousands of BAC clone fingerprints per day. That is why background peaks removal has become an important issue and needs to be automatized, especially in capillary electrophoresis based fingerprints. At the moment, the only tools available for such a task are GenoProfiler and its descendant FPMiner. The large variation in the quality of fingerprints that is usually present in large fingerprinting projects represents a major difficulty in the correct removal of background peaks that has only been partially addressed by the methods so far adopted that all require a long manual optimization of parameters. Thus, we implemented a new data-independent tool, FPB (FingerPrint Background removal), suitable for large scale projects as well as mapping of few clones. FPB is freely available at http://www.appliedgenomics.org/tools.php. FPB was used to remove the background from all fingerprints of three grapevine physical map projects. The first project consists of about 50,000 fingerprints, the second one consists of about 70,000 fingerprints, and the third one consists of about 45,000 fingerprints. In all cases a successful assembly was built.

  1. Background Tsunamis off the coast of Japan

    NASA Astrophysics Data System (ADS)

    Watada, S.

    2016-12-01

    JMA has been monitoring tsunamis at the outer rise of the Japan trench in real time since 2012 by using three DART stations separated about 100 km apart. Continuous tsunami data from Bottom Pressure Recorders (BPR) have been recovered and investigated for the background tsunamis, or long period surface gravity waves. Cross-correlation of two-hour-long records from two stations were computed and stacked for every month in 1.5 years. Each month, the cross-correlated ocean bottom pressure records starts with 1mm amplitude at zero time lag, indicating background tsunami wavelength can be as long as 200 km. The cross-correlation amplitude gradually increases up to 2mm at a time lag corresponding to the arrival time of the surface gravity waves with sharp pressure decrease due to the ocean depth. The wave period at the amplitude maximum is about 400 sec independent from station distance. Dispersed surface gravity waves follow after the amplitude peak. Seasonal variation of the amplitude the background tsunami is not clear, i.e., at one pair shows a larger amplitude in summer season by about 20% but other pairs do not. To look at the background tsunami propagation of longer distance, cross-correlations between DART 21413 (ESE Tokyo) and 21418 (NE Tokyo) have been computed operated by NOAA. Two stations are separated about 900 km. A one-year stack of the one-day-long cross-correlated records enhances weaker background tsunami waveforms with similar features but with a much smaller amplitude at zero time lag, indicating that background tsunami wavelength is smaller than 900km The merit of cross-correlation analysis of continuously recorded tsunamis is that the tsunami propagation can be obtained by the cross-correlation of observed data without a tsunami simulation.

  2. Elastic lattice in an incommensurate background

    SciTech Connect

    Dickman, R.; Chudnovsky, E.M. )

    1995-01-01

    We study a harmonic triangular lattice, which relaxes in the presence of an incommensurate short-wavelength potential. Monte Carlo simulations reveal that the elastic lattice exhibits only short-ranged translational correlations, despite the absence of defects in either lattice. Extended orientational order, however, persists in the presence of the background. Translational correlation lengths exhibit approximate power-law dependence upon cooling rate and background strength. Our results may be relevant to Wigner crystals, atomic monolayers on crystals surfaces, and flux-line and magnetic bubble lattices.

  3. Cosmic microwave background probes models of inflation

    NASA Technical Reports Server (NTRS)

    Davis, Richard L.; Hodges, Hardy M.; Smoot, George F.; Steinhardt, Paul J.; Turner, Michael S.

    1992-01-01

    Inflation creates both scalar (density) and tensor (gravity wave) metric perturbations. We find that the tensor-mode contribution to the cosmic microwave background anisotropy on large-angular scales can only exceed that of the scalar mode in models where the spectrum of perturbations deviates significantly from scale invariance. If the tensor mode dominates at large-angular scales, then the value of DeltaT/T predicted on 1 deg is less than if the scalar mode dominates, and, for cold-dark-matter models, bias factors greater than 1 can be made consistent with Cosmic Background Explorer (COBE) DMR results.

  4. Gamma radiation background measurements from Spacelab 2

    NASA Technical Reports Server (NTRS)

    Paciesas, William S.; Gregory, John C.; Fishman, Gerald J.

    1988-01-01

    A Nuclear Radiation Monitor incorporating a NaI(Tl) scintillation detector was flown as part of the verification flight instrumentation on the Spacelab 2 mission, July 29 to August 6, 1985. Gamma-ray spectra were measured with better than 20 s resolution throughout most of the mission in the energy range 0.1 to 30 MeV. Knowledge of the decay characteristics and the geomagnetic dependence of the counting rates enable measurement of the various components of the Spacelab gamma-ray background: prompt secondary radiation, Earth albedo, and delayed induced radioactivity. The status of the data analysis and present relevant examples of typical background behavior are covered.

  5. Gamma radiation background measurements from Spacelab 2

    NASA Technical Reports Server (NTRS)

    Paciesas, William S.; Gregory, John C.; Fishman, Gerald J.

    1989-01-01

    A Nuclear Radiation Monitor incorporating a NaI(Tl) scintillation detector was flown as part of the verification flight instrumentation on the Spacelab 2 mission, July 29 to August 6, 1985. Gamma-ray spectra were measured with better than 20 s resolution throughout most of the mission in the energy range 0.1 to 30 MeV. Knowledge of the decay characteristics and the geomagnetic dependence of the counting rates enable measurement of the various components of the Spacelab gamma-ray background: prompt secondary radiation, earth albedo, and delayed induced radioactivity. The status of the data analysis and present relevant examples of typical background behavior are covered.

  6. Experimental limits of the extreme ultraviolet background

    NASA Technical Reports Server (NTRS)

    Wulf-Mathies, C.; Grewing, M.; Kraemer, G.; Schulz-Luepertz, E.; Kimble, R.; Bixler, J.; Bowyer, S.

    1983-01-01

    Photometric observations of the diffuse extreme ultraviolet background with two photometers having bandpasses of 750-940 A and 1040-1080 A are reported. The payload, which was flown aboard an ARIES sounding rocket in June 1982, is described, including the electron detectors, filters, and calibration. The operation of the probe during the experiment, including its motions, are described. The primary experiment involved spectroscopic observation of the hot white dwarf HZ43. The photometer count rate is shown and the measurements of the diffuse background are compared with theoretical predictions. Despite the lower limits obtained using a narrowband detector, the measurements are not sensitive enough to draw any relevant astrophysical conclusions.

  7. Cognitive test performance and background music.

    PubMed

    Cockerton, T; Moore, S; Norman, D

    1997-12-01

    This study examined the effects of background music on test performance. In a repeated-measures design 30 undergraduates completed two cognitive tests, one in silence and the other with background music. Analysis suggested that music facilitated cognitive performance compared with the control condition of no music: more questions were completed and more answers were correct. There was no difference in heart rate under the two conditions. The improved performance under the music condition might be directly related to the type of music used.

  8. Compensatable muon collider calorimeter with manageable backgrounds

    SciTech Connect

    Raja, Rajendran

    2015-02-17

    A method and system for reducing background noise in a particle collider, comprises identifying an interaction point among a plurality of particles within a particle collider associated with a detector element, defining a trigger start time for each of the pixels as the time taken for light to travel from the interaction point to the pixel and a trigger stop time as a selected time after the trigger start time, and collecting only detections that occur between the start trigger time and the stop trigger time in order to thereafter compensate the result from the particle collider to reduce unwanted background detection.

  9. Macroeconomic Policies to Reduce the Current-Account Deficit: Technical Background

    DTIC Science & Technology

    1989-08-01

    interest rates .7 In Table 1, domestic absorption (equations 1 and 17... interest rate normalized from money demand function r = f ( mj/p, q ) where irij = n*m 12. Long-term interest rate rl = rlXO + O/O + rl6))󈧝 13...term interest rate normalized from money demand function r* = f ( m\\/p\\ q ) where • • * m j = n «m 28. Long-term interest rate rl’ = rl^.ai + r’VCl +

  10. The United States Navy and Israeli Navy: Background, Current Issues, Scenarios, and Prospects

    DTIC Science & Technology

    2012-02-01

    navies of both countries, together with the U. S. Navy, held joint search and rescue exercises termed “Reliant Mermaid .”111 The exercises also enabled...Turkey postponed the Reliant Mermaid exercise scheduled for November 2000 due to growing strife between Israel and the Palestinians. The exercise

  11. A wasting syndrome in Swedish moose (Alces alces): background and current hypotheses.

    PubMed

    Broman, Emil; Wallin, Kjell; Stéen, Margareta; Cederlund, Göran

    2002-08-01

    In the 1980s, people in Sweden frequently responded to moose (Alces alces) found dead or in poor physical condition. The number of moose submitted for routine investigations to the National Veterinary Institute (SVA) increased tenfold and the hunters in Alvsborg County were especially concerned. Later, a complex wasting syndrome was described and reports of moose suffering from the syndrome have been collected since 1991. Today, there is no definitive answer as to the underlying causel(s) of the syndrome, but there are several plausible hypotheses that can be divided into two groups: food-related and host-parasite related. The food-related hypotheses are postulated to have any of the following ultimate causes: acidification/liming, browser density/food production or pollution. Our view is that few of the hypotheses have been critically tested. Most of the hypotheses are supported by some observations, which is to be expected because these are post-hoc attempts to explain these very observations.

  12. Bovine spongiform encephalopathy and variant Creutzfeldt-Jakob disease: background, evolution, and current concerns.

    PubMed Central

    Brown, P.; Will, R. G.; Bradley, R.; Asher, D. M.; Detwiler, L.

    2001-01-01

    The epidemic of bovine spongiform encephalopathy (BSE) in the United Kingdom, which began in 1986 and has affected nearly 200,000 cattle, is waning to a conclusion, but leaves in its wake an outbreak of human Creutzfeldt-Jakob disease, most probably resulting from the consumption of beef products contaminated by central nervous system tissue. Although averaging only 10-15 cases a year since its first appearance in 1994, its future magnitude and geographic distribution (in countries that have imported infected British cattle or cattle products, or have endogenous BSE) cannot yet be predicted. The possibility that large numbers of apparently healthy persons might be incubating the disease raises concerns about iatrogenic transmissions through instrumentation (surgery and medical diagnostic procedures) and blood and organ donations. Government agencies in many countries continue to implement new measures to minimize this risk. PMID:11266289

  13. Effects of Toroidal Forces in Current Loops Embedded in a Background Plasma.

    DTIC Science & Technology

    1987-12-29

    loop in stable MHD equilibrium described by c’V x B - Vp = 0 where the major radial forces as well as the minor e radial forces arc explicitly...dimensional semi-toroidal equilibria previously identified. ’’It is found that somec equilibrium loops are u~nstable jo such perturbations. resulting in...pressure gradient and drag force due to the ambient gas. For the equilibrium loops studied, the motion is found to be subsonic. Time evolution of the

  14. Development of Social Work Education in China: Background, Current Status, and Prospects

    ERIC Educational Resources Information Center

    Li, Yingsheng; Han, Wen-Jui; Huang, Chien-Chung

    2012-01-01

    China's social work education dates back to the 1920s, but the profession disappeared for 36 years after the establishment of the People's Republic of China. Not until the late 1980s was social work education in China revived. At the turn of the new century, the Central Committee of the Chinese Communist Party and the State Council supported the…

  15. Charge and current neutralization in the formation of ion rings in a background plasma

    SciTech Connect

    Oliver, B.V.; Ryutov, D.D.; Sudan, R.N. )

    1994-10-01

    For typical field-reversed ion ring experiments, an intense ion beam is injected across a plasma-filled magnetic cusp and propagated into a solenoidal field downstream. The characteristic time [tau] satisfies 2[pi]/[Omega][sub [ital e

  16. Development of Social Work Education in China: Background, Current Status, and Prospects

    ERIC Educational Resources Information Center

    Li, Yingsheng; Han, Wen-Jui; Huang, Chien-Chung

    2012-01-01

    China's social work education dates back to the 1920s, but the profession disappeared for 36 years after the establishment of the People's Republic of China. Not until the late 1980s was social work education in China revived. At the turn of the new century, the Central Committee of the Chinese Communist Party and the State Council supported the…

  17. Issues Affecting Crime Victims: Background, Current Status, and Implications for Older Persons.

    ERIC Educational Resources Information Center

    American Association of Retired Persons, Washington, DC.

    This packet contains summaries of issues concerning provisions of law affecting victims and their involvement in the criminal justice system. The packet opens by stating that unless victims and witnesses come forward and report criminal activity to law enforcement authorities and are subsequently willing to testify and endure cross-examination in…

  18. Mumps: a current epidemiologic pattern as a necessary background for the choice of a vaccination strategy.

    PubMed

    Zotti, C; Ossola, O; Barberis, R; Castella, A; Ruggenini, A M

    1999-08-01

    Before the measles mumps rubella (MMR) vaccination was widely offered, the epidemiologic data about mumps (morbidity, immunization level, vaccine coverage) were analyzed in Piedmont region (Italy). The disease had a 3- to 5-year epidemic recurrence with morbidity rate between 40 and 150/100,000; the surveillance conducted by 'sentinel' pediatricians showed that the notifications underestimated the real data by about 5- to 7-fold. The 12-year-old subjects showed an immunization level (reached by the disease or the vaccination) of about 50% and their parents tended to refuse the MMR vaccination. Only 54% of the 3- to 5-year-old children received the MMR vaccine in the second year of life and the frequency of the vaccination failure was about 10%. The strategy of vaccination should take into account this epidemiologic pattern, to program an offer adequate to reach mumps control/elimination; the strategy of our region should include the active offer in the second year of life to reach higher coverage, a second offer at 4-6 and/or 12 years of life, when other vaccinations are given and the choice of a highly efficacious vaccine. The improvement of the notification system could also allow a more sensitive surveillance of epidemiologic patterns.

  19. The Supplemental Educational Opportunity Grant Program: Background and Current Issues. CRS Report for Congress.

    ERIC Educational Resources Information Center

    Redd, Kenneth

    The Supplemental Educational Opportunity Grant (SEOG) program provides financial assistance to low-income undergraduate students attending postsecondary education institutions and is authorized by Title IV of the Higher Education Act. The program is administered on the campus of each participating postsecondary education institution which uses…

  20. Global modes in Saturn’s main rings. Theoretical background and current issues

    NASA Astrophysics Data System (ADS)

    Longaretti, Pierre-Yves

    2017-06-01

    The dynamics of dense ring systems may conveniently be divided into two main topics: local structures, mostly driven be local, incoherent instabilities (most prominently, self-gravitational wakes and local viscous overstabilities) and global structures, involving in particular non-axisymmetric features over the whole extent in azimuth. The latter include density and bending waves, global narrow ring modes and edge modes; these structures can be globally viscously overstable.All global modes have a common dynamical origin and can be described in a unified dynamical framework, which will be reviewed in the first part of the talk. In particular, all planar narrow ring modes and edge modes can be described as trapped density waves and theoretically investigated as a nonlinear eigenvalue problem.The second part of the talk will focus on salient problems, some of which were discovered and characterized during the Cassini mission. These include, e.g., the numerous edge modes observed at gap edges and narrow ring edges, the peculiar structure of the B ring edge and the alternating series of gaps and rings populating the Cassini division. The possible dynamical origin of these structures will be reviewed; if available at the time of the conference, new numerical simulations investigating the dynamics of the B ring edge will be presented.

  1. The Journey of Elastography: Background, Current Status, and Future Possibilities in Breast Cancer Diagnosis.

    PubMed

    Faruk, Tasnuva; Islam, Md Kafiul; Arefin, Sams; Haq, Md Zahurul

    2015-10-01

    Elastography is a promising way to assess tissue differences regarding stiffness or elasticity for what was historically assessed manually by palpation. Combined with conventional imaging modalities (eg, ultrasonography [US]), elastography can potentially evaluate the stiffness of a breast lesion and consequently help to detect malignant breast tumor from benign ones. Recent studies show that ultrasonographic elastography (USE) provides higher image quality compared with conventional B-mode US or mammography during breast cancer diagnosis, which eventually helps to reduce false-positive results (ie, increased specificity) and therefore is useful in avoiding breast biopsy. This article reviews the basics of elastography technique, classifications, diagnosis results obtained from clinical studies to date for differentiating malignant breast tumors from benign lesions, and its future possibilities. In addition, this article generalizes different elastography methods, modes, and associated imaging modalities in a simpler way and attempts to identify misconceptions and confusion related to existing elastography techniques. It also makes an effort to identify the gaps of information that need to be filled so that interested researchers can get an overall idea of elastography-based methods in a convenient way to carry out their research on breast elastography for prospective future applications, eg, breast cancer diagnosis or even in intraoperative breast tumor localization.

  2. Stochastic gravitational wave background from cold dark matter halos

    SciTech Connect

    Carbone, Carmelita; Baccigalupi, Carlo; Matarrese, Sabino

    2006-03-15

    The current knowledge of cosmological structure formation suggests that Cold Dark Matter (CDM) halos possess a nonspherical density profile, implying that cosmic structures can be potential sources of gravitational waves via power transfer from scalar perturbations to tensor metric modes in the nonlinear regime. By means of a previously developed mathematical formalism and a triaxial collapse model, we numerically estimate the stochastic gravitational-wave background generated by CDM halos during the fully nonlinear stage of their evolution. Our results suggest that the energy density associated with this background is comparable to that produced by primordial tensor modes at frequencies {nu}{approx_equal}10{sup -18}-10{sup -17} Hz if the energy scale of inflation is V{sup 1/4}{approx_equal}1-2x10{sup 15} GeV, and that these gravitational waves could give rise to several cosmological effects, including secondary CMB anisotropy and polarization.

  3. Background-Limited Infrared-Submillimeter Spectroscopy (BLISS)

    NASA Technical Reports Server (NTRS)

    Bradford, Charles Matt

    2004-01-01

    The bulk of the cosmic far-infrared background light will soon be resolved into its individual sources with Spitzer, Astro-F, Herschel, and submm/mm ground-based cameras. The sources will be dusty galaxies at z approximately equal to 1-4. Their physical conditions and processes in these galaxies are directly probed with moderate-resolution spectroscopy from 20 micrometers to 1 mm. Currently large cold telescopes are being combined with sensitive direct detectors, offering the potential for mid-far-IR spectroscopy at the background limit (BLISS). The capability will allow routine observations of even modest high-redshift galaxies in a variety of lines. The BLISS instrument's capabilities are described in this presentation.

  4. Cosmic microwave background observables of small field models of inflation

    SciTech Connect

    Ben-Dayan, Ido; Brustein, Ram E-mail: ramyb@bgu.ac.il

    2010-09-01

    We construct a class of single small field models of inflation that can predict, contrary to popular wisdom, an observable gravitational wave signal in the cosmic microwave background anisotropies. The spectral index, its running, the tensor to scalar ratio and the number of e-folds can cover all the parameter space currently allowed by cosmological observations. A unique feature of models in this class is their ability to predict a negative spectral index running in accordance with recent cosmic microwave background observations. We discuss the new class of models from an effective field theory perspective and show that if the dimensionless trilinear coupling is small, as required for consistency, then the observed spectral index running implies a high scale of inflation and hence an observable gravitational wave signal. All the models share a distinct prediction of higher power at smaller scales, making them easy targets for detection.

  5. The faint galaxy contribution to the diffuse extragalactic background light

    NASA Technical Reports Server (NTRS)

    Cole, Shaun; Treyer, Marie-Agnes; Silk, Joseph

    1992-01-01

    Models of the faint galaxy contribution to the diffuse extragalactic background light are presented, which are consistent with current data on faint galaxy number counts and redshifts. The autocorrelation function of surface brightness fluctuations in the extragalactic diffuse light is predicted, and the way in which these predictions depend on the cosmological model and assumptions of biasing is determined. It is confirmed that the recent deep infrared number counts are most compatible with a high density universe (Omega-0 is approximately equal to 1) and that the steep blue counts then require an extra population of rapidly evolving blue galaxies. The faintest presently detectable galaxies produce an interesting contribution to the extragalactic diffuse light, and still fainter galaxies may also produce a significant contribution. These faint galaxies still only produce a small fraction of the total optical diffuse background light, but on scales of a few arcminutes to a few degrees, they produce a substantial fraction of the fluctuations in the diffuse light.

  6. Cutting Balloon: Review on Principles and Background of Use in Peripheral Arteries

    SciTech Connect

    Cejna, Manfred

    2005-05-15

    This review describes peripheral use of cutting balloon (CB) angioplasty (CBA), its characteristics, and its distinction from conventional BA and describes the experimental and clinical background of its current use in peripheral arteries.

  7. Merit or Family Background? Problems in Research Policy Initiatives in Japan.

    ERIC Educational Resources Information Center

    LeTendre, Gerald K.; Rohlen, Thomas P.; Zeng, Kangmin

    1998-01-01

    Studied national educational datasets in Japan during the post-World War II era. Found that current datasets do not contain questions about family background or rank of school attended that are detailed enough to permit an analysis of the impact of family background on educational attainment. (SLD)

  8. THE COSMIC INFRARED BACKGROUND EXPERIMENT (CIBER): A SOUNDING ROCKET PAYLOAD TO STUDY THE NEAR INFRARED EXTRAGALACTIC BACKGROUND LIGHT

    SciTech Connect

    Zemcov, M.; Bock, J.; Hristov, V.; Levenson, L. R.; Mason, P.; Arai, T.; Matsumoto, T.; Matsuura, S.; Tsumura, K.; Wada, T.; Battle, J.; Cooray, A.; Keating, B.; Renbarger, T.; Kim, M. G.; Lee, D. H.; Nam, U. W.; Sullivan, I.; Suzuki, K.

    2013-08-15

    The Cosmic Infrared Background Experiment (CIBER) is a suite of four instruments designed to study the near infrared (IR) background light from above the Earth's atmosphere. The instrument package comprises two imaging telescopes designed to characterize spatial anisotropy in the extragalactic IR background caused by cosmological structure during the epoch of reionization, a low resolution spectrometer to measure the absolute spectrum of the extragalactic IR background, and a narrow band spectrometer optimized to measure the absolute brightness of the zodiacal light foreground. In this paper we describe the design and characterization of the CIBER payload. The detailed mechanical, cryogenic, and electrical design of the system are presented, including all system components common to the four instruments. We present the methods and equipment used to characterize the instruments before and after flight, and give a detailed description of CIBER's flight profile and configurations. CIBER is designed to be recoverable and has flown four times, with modifications to the payload having been informed by analysis of the first flight data. All four instruments performed to specifications during the subsequent flights, and the scientific data from these flights are currently being analyzed.

  9. The Cosmic Infrared Background Experiment (CIBER): A Sounding Rocket Payload to Study the near Infrared Extragalactic Background Light

    NASA Astrophysics Data System (ADS)

    Zemcov, M.; Arai, T.; Battle, J.; Bock, J.; Cooray, A.; Hristov, V.; Keating, B.; Kim, M. G.; Lee, D. H.; Levenson, L. R.; Mason, P.; Matsumoto, T.; Matsuura, S.; Nam, U. W.; Renbarger, T.; Sullivan, I.; Suzuki, K.; Tsumura, K.; Wada, T.

    2013-08-01

    The Cosmic Infrared Background Experiment (CIBER) is a suite of four instruments designed to study the near infrared (IR) background light from above the Earth's atmosphere. The instrument package comprises two imaging telescopes designed to characterize spatial anisotropy in the extragalactic IR background caused by cosmological structure during the epoch of reionization, a low resolution spectrometer to measure the absolute spectrum of the extragalactic IR background, and a narrow band spectrometer optimized to measure the absolute brightness of the zodiacal light foreground. In this paper we describe the design and characterization of the CIBER payload. The detailed mechanical, cryogenic, and electrical design of the system are presented, including all system components common to the four instruments. We present the methods and equipment used to characterize the instruments before and after flight, and give a detailed description of CIBER's flight profile and configurations. CIBER is designed to be recoverable and has flown four times, with modifications to the payload having been informed by analysis of the first flight data. All four instruments performed to specifications during the subsequent flights, and the scientific data from these flights are currently being analyzed.

  10. Study of robot landmark recognition with complex background

    NASA Astrophysics Data System (ADS)

    Huang, Yuqing; Yang, Jia

    2007-12-01

    It's of great importance for assisting robot in path planning, position navigating and task performing by perceiving and recognising environment characteristic. To solve the problem of monocular-vision-oriented landmark recognition for mobile intelligent robot marching with complex background, a kind of nested region growing algorithm which fused with transcendental color information and based on current maximum convergence center is proposed, allowing invariance localization to changes in position, scale, rotation, jitters and weather conditions. Firstly, a novel experiment threshold based on RGB vision model is used for the first image segmentation, which allowing some objects and partial scenes with similar color to landmarks also are detected with landmarks together. Secondly, with current maximum convergence center on segmented image as each growing seed point, the above region growing algorithm accordingly starts to establish several Regions of Interest (ROI) orderly. According to shape characteristics, a quick and effectual contour analysis based on primitive element is applied in deciding whether current ROI could be reserved or deleted after each region growing, then each ROI is judged initially and positioned. When the position information as feedback is conveyed to the gray image, the whole landmarks are extracted accurately with the second segmentation on the local image that exclusive to landmark area. Finally, landmarks are recognised by Hopfield neural network. Results issued from experiments on a great number of images with both campus and urban district as background show the effectiveness of the proposed algorithm.

  11. CBI2: Current Status

    NASA Astrophysics Data System (ADS)

    Sievers, Jonathan L.; CBI Collaboration

    2006-12-01

    The Cosmic Background Imager is a sensitive 13-element radio interferometer operating at 5070m in the Chilean Andes (the future ALMA site). We have upgraded the CBI's 0.9m dishes with 1.4m dishes, effectively doubling the sensitivity. CBI2's primary science goal is a better measurement of the CMB power spectrum in the ell 2000-3000 range, where previous CBI measurements found an excess of power at 30 GHz over what was expected. We will also observe galaxy clusters and diffuse emission in the Milky Way with CBI2. We present the current status of CBI2, the errors on the CMB spectrum we expect to achieve, and hopefully early results. The CBI is a collaboration between Caltech, CITA, NRAO, MPI-Radioastronomie, Oxford, Manchester, Universidad de Chile, and Universidad de Concepcion.

  12. ESTIMATION OF BACKGROUND LEVELS OF CONTAMINANTS

    EPA Science Inventory

    Samples from hazardous waste site investigations frequently come from two or more statistical populations. Assessment of "background" levels of contaminants can be a significant problem. This problem is being investigated at the US EPA's EMSL in Las Vegas. This paper describes a ...

  13. 32 CFR 770.42 - Background.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ACCESS TO PARTICULAR INSTALLATIONS Base Entry Regulations for Naval Submarine Base New London, Groton, Connecticut § 770.42 Background. Naval Submarine Base New London maintains and operates facilities to support training and experimental operations of the submarine force including providing support to...

  14. 32 CFR 770.42 - Background.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ACCESS TO PARTICULAR INSTALLATIONS Base Entry Regulations for Naval Submarine Base New London, Groton, Connecticut § 770.42 Background. Naval Submarine Base New London maintains and operates facilities to support training and experimental operations of the submarine force including providing support to...

  15. 32 CFR 770.42 - Background.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ACCESS TO PARTICULAR INSTALLATIONS Base Entry Regulations for Naval Submarine Base New London, Groton, Connecticut § 770.42 Background. Naval Submarine Base New London maintains and operates facilities to support training and experimental operations of the submarine force including providing support to...

  16. 32 CFR 770.42 - Background.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ACCESS TO PARTICULAR INSTALLATIONS Base Entry Regulations for Naval Submarine Base New London, Groton, Connecticut § 770.42 Background. Naval Submarine Base New London maintains and operates facilities to support training and experimental operations of the submarine force including providing support to...

  17. 28 CFR 23.2 - Background.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... of intelligence data necessary to support control of serious criminal activity may represent potential threats to the privacy of individuals to whom such data relates, policy guidelines for Federally... Administration DEPARTMENT OF JUSTICE CRIMINAL INTELLIGENCE SYSTEMS OPERATING POLICIES § 23.2 Background. It is...

  18. 28 CFR 23.2 - Background.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... of intelligence data necessary to support control of serious criminal activity may represent potential threats to the privacy of individuals to whom such data relates, policy guidelines for Federally... Administration DEPARTMENT OF JUSTICE CRIMINAL INTELLIGENCE SYSTEMS OPERATING POLICIES § 23.2 Background. It is...

  19. 28 CFR 23.2 - Background.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... of intelligence data necessary to support control of serious criminal activity may represent potential threats to the privacy of individuals to whom such data relates, policy guidelines for Federally... Administration DEPARTMENT OF JUSTICE CRIMINAL INTELLIGENCE SYSTEMS OPERATING POLICIES § 23.2 Background. It is...

  20. 28 CFR 23.2 - Background.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... of intelligence data necessary to support control of serious criminal activity may represent potential threats to the privacy of individuals to whom such data relates, policy guidelines for Federally... Administration DEPARTMENT OF JUSTICE CRIMINAL INTELLIGENCE SYSTEMS OPERATING POLICIES § 23.2 Background. It is...

  1. 28 CFR 23.2 - Background.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... of intelligence data necessary to support control of serious criminal activity may represent potential threats to the privacy of individuals to whom such data relates, policy guidelines for Federally... Administration DEPARTMENT OF JUSTICE CRIMINAL INTELLIGENCE SYSTEMS OPERATING POLICIES § 23.2 Background. It is...

  2. 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.

  3. 32 CFR 735.2 - Background.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 5 2012-07-01 2012-07-01 false Background. 735.2 Section 735.2 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY PERSONNEL REPORTING BIRTHS AND DEATHS IN COOPERATION...) policy is that military services will require their members to make official record of births,...

  4. 32 CFR 735.2 - Background.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 5 2014-07-01 2014-07-01 false Background. 735.2 Section 735.2 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY PERSONNEL REPORTING BIRTHS AND DEATHS IN COOPERATION...) policy is that military services will require their members to make official record of births,...

  5. 32 CFR 735.2 - Background.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 5 2011-07-01 2011-07-01 false Background. 735.2 Section 735.2 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY PERSONNEL REPORTING BIRTHS AND DEATHS IN COOPERATION...) policy is that military services will require their members to make official record of births,...

  6. 32 CFR 735.2 - Background.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 5 2013-07-01 2013-07-01 false Background. 735.2 Section 735.2 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY PERSONNEL REPORTING BIRTHS AND DEATHS IN COOPERATION...) policy is that military services will require their members to make official record of births,...

  7. ESTIMATION OF BACKGROUND LEVELS OF CONTAMINANTS

    EPA Science Inventory

    Samples from hazardous waste site investigations frequently come from two or more statistical populations. Assessment of "background" levels of contaminants can be a significant problem. This problem is being investigated at the US EPA's EMSL in Las Vegas. This paper describes a ...

  8. 33 CFR 236.4 - Background.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... control, beach erosion control and hurricane protection, hydroelectric power, recreation, water supply... Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE WATER... QUALITY § 236.4 Background. (a) The role of the Corps of Engineers in the development of water and...

  9. Contemporary Rhetoric: A Conceptual Background with Readings.

    ERIC Educational Resources Information Center

    Winterowd, W. Ross, Ed.

    Designed for use by composition students as well as teachers, the essays and background discussions in this book address themselves to questions of theory and practice in rhetoric. The book is divided into sections on invention, form, and style, and contains articles by such authors as Janet Emig, Wayne C. Booth, Richard L. Larson, Kenneth Burke,…

  10. Does Social Background Influence Political Science Grades?

    ERIC Educational Resources Information Center

    Tiruneh, Gizachew

    2013-01-01

    This paper tests a hypothesized linear relationship between social background and final grades in several political science courses that I taught at the University of Central Arkansas. I employ a cross-sectional research design and ordinary least square (OLS) estimators to test the foregoing hypothesis. Relying on a sample of up to 204…

  11. Social Background Differences in Early Family Behavior

    ERIC Educational Resources Information Center

    Schoen, Robert; Landale, Nancy S.; Daniels, Kimberly; Cheng, Yen-Hsin Alice

    2009-01-01

    Social background has historically been recognized as a major factor influencing family behavior, though recent work has largely emphasized racial/ethnic influences. Here we use 1994 - 1995 and 2001 - 2002 Add Health data to examine the cohabitation, first marriage, and first birth experience of young women. In a multi state life table context,…

  12. Light incoherence due to background space fluctuations

    NASA Astrophysics Data System (ADS)

    Maziashvili, Michael

    2016-12-01

    Working by analogy, we use the description of light fluctuations due to random collisions of the radiating atoms to figure out why the reduction of the coherence for light propagating a cosmological distance in the fluctuating background space is negligibly small to be observed by the stellar interferometry.

  13. Does Social Background Influence Political Science Grades?

    ERIC Educational Resources Information Center

    Tiruneh, Gizachew

    2013-01-01

    This paper tests a hypothesized linear relationship between social background and final grades in several political science courses that I taught at the University of Central Arkansas. I employ a cross-sectional research design and ordinary least square (OLS) estimators to test the foregoing hypothesis. Relying on a sample of up to 204…

  14. Background Oriented Schlieren Using Celestial Objects

    NASA Technical Reports Server (NTRS)

    Haering, Edward, A., Jr. (Inventor); Hill, Michael A (Inventor)

    2017-01-01

    The present invention is a system and method of visualizing fluid flow around an object, such as an aircraft or wind turbine, by aligning the object between an imaging system and a celestial object having a speckled background, taking images, and comparing those images to obtain fluid flow visualization.

  15. Employment and Training Legislation-1968; Background Information.

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. Senate Committee on Labor and Public Welfare.

    This volume supplied background information for employment and training legislation for the Committee on Labor and Public Welfare of the United States Senate for 1968. It includes: (1) excerpts from reports and recommendations of national committees and commissions on civil disorders, rural poverty, technology and automation, food and fiber, and…

  16. Argon-39 Background in DUNE Photon Detectors

    NASA Astrophysics Data System (ADS)

    Sinev, Gleb; DUNE Collaboration

    2016-03-01

    The Deep Underground Neutrino Experiment (DUNE) is a 40-kt liquid argon detector that will be constructed 5000 ft underground in the Sanford Underground Research Facility in order to study neutrino and proton decay physics. Instrumenting liquid argon with photon detectors to record scintillation in addition to the ionization signal can significantly improve time and energy resolution of the experiment. Argon produces light with wavelength of 128 nm. The reference design for the photon detectors includes acrylic bars covered in wavelength shifter, where the scintillation light can be captured and reemitted with longer wavelengths, then detected using silicon photomultipliers. Radiological backgrounds may noticeably deteriorate the photon detection system performance, especially for low-energy interactions. A particularly important background comes from argon-39 decays, because argon-39 is present in natural argon that will be used in DUNE and the background rate increases with the size of the experiment. The effect of the argon-39 background has been studied and is presented in this talk.

  17. 28 CFR 61.1 - Background.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Administration DEPARTMENT OF JUSTICE (CONTINUED) PROCEDURES FOR IMPLEMENTING THE NATIONAL ENVIRONMENTAL POLICY ACT General § 61.1 Background. (a) The National Environmental Policy Act of 1969 (NEPA), 42 U.S.C... environmental effects of their proposed actions in their decisionmaking and to prepare detailed environmental...

  18. 32 CFR 1290.5 - Background.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Background. 1290.5 Section 1290.5 National Defense Other Regulations Relating to National Defense DEFENSE LOGISTICS AGENCY MISCELLANEOUS PREPARING... those rare violations in which military discipline is the paramount consideration, or where the Federal...

  19. 32 CFR 1290.5 - Background.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Background. 1290.5 Section 1290.5 National Defense Other Regulations Relating to National Defense DEFENSE LOGISTICS AGENCY MISCELLANEOUS PREPARING... those rare violations in which military discipline is the paramount consideration, or where the Federal...

  20. 32 CFR 1290.5 - Background.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Background. 1290.5 Section 1290.5 National Defense Other Regulations Relating to National Defense DEFENSE LOGISTICS AGENCY MISCELLANEOUS PREPARING... those rare violations in which military discipline is the paramount consideration, or where the Federal...

  1. 32 CFR 1290.5 - Background.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Background. 1290.5 Section 1290.5 National Defense Other Regulations Relating to National Defense DEFENSE LOGISTICS AGENCY MISCELLANEOUS PREPARING... those rare violations in which military discipline is the paramount consideration, or where the Federal...

  2. THE TEMPERATURE OF THE COSMIC MICROWAVE BACKGROUND

    SciTech Connect

    Fixsen, D. J.

    2009-12-20

    The Far InfraRed Absolute Spectrophotometer data are independently recalibrated using the Wilkinson Microwave Anisotropy Probe data to obtain a cosmic microwave background (CMB) temperature of 2.7260 +- 0.0013. Measurements of the temperature of the CMB are reviewed. The determination from the measurements from the literature is CMB temperature of 2.72548 +- 0.00057 K.

  3. 44 CFR 350.3 - Background.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Background. 350.3 Section 350.3 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND... coordinate civil emergency planning, management and assistance functions and to represent the President in...

  4. 16 CFR 1402.2 - Background.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... ANTENNAS, TV ANTENNAS, AND SUPPORTING STRUCTURES § 1402.2 Background. As a result of numerous... and their supporting structures so that consumers can be made aware of the hazards involved and of... antennas, outside TV antennas, and supporting structures due to contact with overhead powerlines....

  5. 16 CFR 1402.2 - Background.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... ANTENNAS, TV ANTENNAS, AND SUPPORTING STRUCTURES § 1402.2 Background. As a result of numerous... and their supporting structures so that consumers can be made aware of the hazards involved and of... antennas, outside TV antennas, and supporting structures due to contact with overhead powerlines....

  6. 16 CFR 1402.2 - Background.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... ANTENNAS, TV ANTENNAS, AND SUPPORTING STRUCTURES § 1402.2 Background. As a result of numerous... and their supporting structures so that consumers can be made aware of the hazards involved and of... antennas, outside TV antennas, and supporting structures due to contact with overhead powerlines....

  7. 16 CFR 1402.2 - Background.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... ANTENNAS, TV ANTENNAS, AND SUPPORTING STRUCTURES § 1402.2 Background. As a result of numerous... and their supporting structures so that consumers can be made aware of the hazards involved and of... antennas, outside TV antennas, and supporting structures due to contact with overhead powerlines....

  8. 16 CFR 1402.2 - Background.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... ANTENNAS, TV ANTENNAS, AND SUPPORTING STRUCTURES § 1402.2 Background. As a result of numerous... and their supporting structures so that consumers can be made aware of the hazards involved and of... antennas, outside TV antennas, and supporting structures due to contact with overhead powerlines....

  9. Building for Reauthorization: Background and Analysis.

    ERIC Educational Resources Information Center

    National Association of Student Financial Aid Administrators, Washington, DC.

    The report provides background information on the next reauthorization of the federal Higher Education Act, and is intended for college and university financial aid officers. An introductory section chronicles the history of federal legislation for student financial aid. The next section outlines the congressional reauthorization process,…

  10. 32 CFR 735.2 - Background.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 5 2010-07-01 2010-07-01 false Background. 735.2 Section 735.2 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY PERSONNEL REPORTING BIRTHS AND DEATHS IN COOPERATION...) policy is that military services will require their members to make official record of births, deaths...

  11. Tonic vibration reflexes and background force level

    NASA Technical Reports Server (NTRS)

    Lackner, James R.; Dizio, Paul; Fisk, John

    1992-01-01

    On earth, the functional stretch reflex is an important component in the maintenance of posture and muscle tone. In parabolic flight experiments, it is evaluated whether the functional stretch reflex, as reflected in the tonic vibration reflex, adjusts appropriately for changes in background gravitoinertial force level. Virtually immediate alterations of appropriate sign occurred.

  12. 32 CFR 770.27 - Background.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ACCESS TO PARTICULAR INSTALLATIONS Base Entry Regulations for Naval Installations in the State of Hawaii § 770.27 Background. (a) Naval installations in Hawaii constitute a significant element of the national... only. (f) These entry regulations are being promulgated under the authority of Commander, Naval...

  13. 32 CFR 770.49 - Background.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ACCESS TO PARTICULAR INSTALLATIONS Base Entry Regulations for Puget Sound Naval Shipyard, Bremerton, Washington § 770.49 Background. (a) Puget Sound Naval Shipyard is a major naval ship repair facility, with operational requirements to complete repairs and overhaul of conventionally powered and nuclear powered...

  14. Effect of Communicator Background on Credibility

    ERIC Educational Resources Information Center

    Panzica, Norman

    1973-01-01

    To help assess the effect of a communicator's perceived background on his credibility, students were asked to rate a speaker on drug abuse. Half the students were led to believe that the speaker had himself used psychotropic drugs regularly. The others were told he had used no such drugs. Differences in mean ratings did not show statistical…

  15. Thermal neutron background measurement in CJPL

    NASA Astrophysics Data System (ADS)

    Zeng, Z. M.; Gong, H.; Yue, Q.; Li, J. M.

    2015-12-01

    This paper describes the measurement of thermal neutron flux in the CJPL underground laboratory in the proximity of the CDEX experiment. A low background thermal neutron detection system is designed which applies a combination of a 3He proportional tube and a 4He proportional tube as the detector. Thermal neutrons can be captured by the 3He proportional tube while the 4He proportional tube is for the purpose of background measurement. The tube wall is made up of oxygen-free copper to reduce the background due to radioactivity of the wall material. The electronics readout system has been developed to store triggered events' waveforms so as to get the amplitude spectrum and monitor the data quality. We observed an average thermal neutron flux of Φ = 4.00 ± 0.08 ×10-6 /cm2 s in the CJPL experiment hall in the proximity of CDEX experiment and the neutron and background events both distribute uniformly along the tube.

  16. Background independent duals of the harmonic oscillator.

    PubMed

    Husain, Viqar

    2006-06-09

    We show that a class of topological field theories are quantum duals of the harmonic oscillator. This is demonstrated by establishing a correspondence between the creation and annihilation operators and nonlocal gauge invariant observables of the topological field theory. The example is used to discuss some issues concerning background independence and the relation of vacuum energy to the problem of time in quantum gravity.

  17. 32 CFR 1290.5 - Background.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Background. 1290.5 Section 1290.5 National Defense Other Regulations Relating to National Defense DEFENSE LOGISTICS AGENCY MISCELLANEOUS PREPARING... laws to all personnel while on Federal property (section 13, title 18 U.S.C., Assimilative Crimes Act). ...

  18. Can one measure the Cosmic Neutrino Background?

    NASA Astrophysics Data System (ADS)

    Faessler, Amand; Hodák, Rastislav; Kovalenko, Sergey; Šimkovic, Fedor

    The Cosmic Microwave Background (CMB) yields information about our Universe at around 380,000 years after the Big Bang (BB). Due to the weak interaction of the neutrinos with matter, the Cosmic Neutrino Background (CNB) should give information about a much earlier time of our Universe, around one second after the BB. Probably, the most promising method to "see" the CNB is the capture of the electron neutrinos from the Background by Tritium, which then decays into 3He and an electron with the energy of the the Q-value = 18.562 keV plus the electron neutrino rest mass. The "KArlsruhe TRItium Neutrino" (KATRIN) experiment, which is in preparation, seems presently the most sensitive proposed method for measuring the electron antineutrino mass. At the same time, KATRIN can also look by the reaction νe(˜1.95K) + 3H → 3He + e-(Q = 18.6keV + mνec2). The capture of the Cosmic Background Neutrinos (CNB) should show in the electron spectrum as a peak by the electron neutrino rest mass above Q. Here, the possibility to see the CNB with KATRIN is studied. A detection of the CNB by KATRIN seems not to be possible at the moment. But KATRIN should be able to determine an upper limit for the local electron neutrino density of the CNB.

  19. 16 CFR 1031.17 - Background.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Background. 1031.17 Section 1031.17 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION GENERAL COMMISSION PARTICIPATION AND COMMISSION... that it was launching a pilot program to open CPSC staff activities for public review and comment....

  20. 32 CFR 770.49 - Background.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 5 2014-07-01 2014-07-01 false Background. 770.49 Section 770.49 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY MISCELLANEOUS RULES RULES LIMITING PUBLIC ACCESS TO PARTICULAR INSTALLATIONS Base Entry Regulations for Puget Sound Naval Shipyard,...

  1. 32 CFR 770.49 - Background.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 5 2011-07-01 2011-07-01 false Background. 770.49 Section 770.49 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY MISCELLANEOUS RULES RULES LIMITING PUBLIC ACCESS TO PARTICULAR INSTALLATIONS Base Entry Regulations for Puget Sound Naval Shipyard,...

  2. 32 CFR 770.49 - Background.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 5 2012-07-01 2012-07-01 false Background. 770.49 Section 770.49 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY MISCELLANEOUS RULES RULES LIMITING PUBLIC ACCESS TO PARTICULAR INSTALLATIONS Base Entry Regulations for Puget Sound Naval Shipyard,...

  3. 32 CFR 770.49 - Background.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 5 2013-07-01 2013-07-01 false Background. 770.49 Section 770.49 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY MISCELLANEOUS RULES RULES LIMITING PUBLIC ACCESS TO PARTICULAR INSTALLATIONS Base Entry Regulations for Puget Sound Naval Shipyard,...

  4. 38 CFR 200.2 - Background.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2013-07-01 2013-07-01 false Background. 200.2 Section 200.2 Pensions, Bonuses, and Veterans' Relief ARMED FORCES RETIREMENT HOME COMPLIANCE WITH THE..., and variety of individual choice; (5) Achieve a balance between population and resource use which will...

  5. 10 CFR 37.25 - Background investigations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Background investigations. 37.25 Section 37.25 Energy NUCLEAR REGULATORY COMMISSION PHYSICAL PROTECTION OF CATEGORY 1 AND CATEGORY 2 QUANTITIES OF RADIOACTIVE... at a minimum: (1) Fingerprinting and an FBI identification and criminal history records check...

  6. 38 CFR 200.2 - Background.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the fullest extent possible, analyses and consultations required by other environmental laws be... NATIONAL ENVIRONMENTAL POLICY ACT § 200.2 Background. (a) The NEPA and the Council on Environmental Quality... prescribe procedures to be followed. Other laws, executive orders, and regulations provide related...

  7. 38 CFR 200.2 - Background.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... the fullest extent possible, analyses and consultations required by other environmental laws be... NATIONAL ENVIRONMENTAL POLICY ACT § 200.2 Background. (a) The NEPA and the Council on Environmental Quality... prescribe procedures to be followed. Other laws, executive orders, and regulations provide related...

  8. 38 CFR 200.2 - Background.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the fullest extent possible, analyses and consultations required by other environmental laws be... NATIONAL ENVIRONMENTAL POLICY ACT § 200.2 Background. (a) The NEPA and the Council on Environmental Quality... prescribe procedures to be followed. Other laws, executive orders, and regulations provide related...

  9. 33 CFR 236.4 - Background.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... QUALITY § 236.4 Background. (a) The role of the Corps of Engineers in the development of water and related..., water quality, fish and wildlife and low-flow augmentation. Laws, executive orders, and national... preserve or enhance critical habitat for fish and wildlife; maintain or enhance water quality;...

  10. Can one measure the Cosmic Neutrino Background?

    NASA Astrophysics Data System (ADS)

    Faessler, Amand; Hodák, Rastislav; Kovalenko, Sergey; Šimkovic, Fedor

    The Cosmic Microwave Background (CMB) yields information about our Universe at around 380,000 years after the Big Bang (BB). Due to the weak interaction of the neutrinos with matter, the Cosmic Neutrino Background (CNB) should give information about a much earlier time of our Universe, around one second after the BB. Probably, the most promising method to “see” the CNB is the capture of the electron neutrinos from the Background by Tritium, which then decays into 3He and an electron with the energy of the the Q-value = 18.562keV plus the electron neutrino rest mass. The “KArlsruhe TRItium Neutrino” (KATRIN) experiment, which is in preparation, seems presently the most sensitive proposed method for measuring the electron antineutrino mass. At the same time, KATRIN can also look by the reaction νe(˜ 1.95K) +3H →3He + e‑(Q = 18.6keV + m νec2). The capture of the Cosmic Background Neutrinos (CNB) should show in the electron spectrum as a peak by the electron neutrino rest mass above Q. Here, the possibility to see the CNB with KATRIN is studied. A detection of the CNB by KATRIN seems not to be possible at the moment. But KATRIN should be able to determine an upper limit for the local electron neutrino density of the CNB.

  11. 14 CFR 1214.302 - Background.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Background. 1214.302 Section 1214.302 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT Payload Specialists for Space... dedicated space flight training, allowing them to concentrate their efforts on the accomplishment of...

  12. 14 CFR 1214.302 - Background.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Background. 1214.302 Section 1214.302 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT Payload Specialists for Space... dedicated space flight training, allowing them to concentrate their efforts on the accomplishment of...

  13. 23 CFR 777.3 - Background.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... NATURAL HABITAT § 777.3 Background. (a) Executive Order 11990 (42 FR 26961, 3 CFR, 1977 Comp., p. 121... natural habitats which result from projects funded pursuant to title 23, U.S. Code, as eligible for... consultation procedures relative to impacts to species listed under the authority of the Act and their habitats...

  14. 23 CFR 777.3 - Background.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... NATURAL HABITAT § 777.3 Background. (a) Executive Order 11990 (42 FR 26961, 3 CFR, 1977 Comp., p. 121... natural habitats which result from projects funded pursuant to title 23, U.S. Code, as eligible for... consultation procedures relative to impacts to species listed under the authority of the Act and their habitats...

  15. 23 CFR 777.3 - Background.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... NATURAL HABITAT § 777.3 Background. (a) Executive Order 11990 (42 FR 26961, 3 CFR, 1977 Comp., p. 121... natural habitats which result from projects funded pursuant to title 23, U.S. Code, as eligible for... consultation procedures relative to impacts to species listed under the authority of the Act and their habitats...

  16. Criminal background checks for home care aides.

    PubMed

    Arrindell, D M

    1997-04-01

    The Health Care Financing Administration recently proposed a rule requiring criminal background checks for all home care aides as a condition of employment. The purpose of the rule is to safeguard against the potential for fraud and abuse in home care, but is it the only solution? And should it be limited to just home care aides?

  17. The ROSAT X-ray background dipole

    NASA Astrophysics Data System (ADS)

    Plionis, M.; Georgantopoulos, I.

    1999-06-01

    We estimate the dipole of the diffuse 1.5-keV X-ray background from the ROSAT all-sky survey map of Snowden et al. We first subtract the diffuse Galactic emission by fitting an exponential scaleheight, finite-radius, disc model to the data. We further exclude regions of low galactic latitudes, of local X-ray emission (e.g. the North Polar Spur) and model them using two different methods. We find that the ROSAT X-ray background dipole points towards (l,b) ~ (288 deg 25 deg) +/- 19 deg in consistency with the cosmic microwave background (within ~ 30 deg) its direction is also in good agreement with the HEAO-1 X-ray dipole at harder energies. The normalized amplitude of the ROSAT XRB dipole is ~ 1.7 per cent. Subtracting from the ROSAT map the expected X-ray background dipole resulting from the reflex motion of the observer with respect to the cosmic rest frame (Compton-Getting effect) we find the large-scale dipole of the X-ray emitting extragalactic sources having an amplitude D_LSS ~ 0.9 D_XRB, in general agreement with the predictions of Lahav et al. We finally estimate that the Virgo cluster is responsible for ~ 20 per cent of the total measured XRB dipole amplitude.

  18. Model-based target and background characterization

    NASA Astrophysics Data System (ADS)

    Mueller, Markus; Krueger, Wolfgang; Heinze, Norbert

    2000-07-01

    Up to now most approaches of target and background characterization (and exploitation) concentrate solely on the information given by pixels. In many cases this is a complex and unprofitable task. During the development of automatic exploitation algorithms the main goal is the optimization of certain performance parameters. These parameters are measured during test runs while applying one algorithm with one parameter set to images that constitute of image domains with very different domain characteristics (targets and various types of background clutter). Model based geocoding and registration approaches provide means for utilizing the information stored in GIS (Geographical Information Systems). The geographical information stored in the various GIS layers can define ROE (Regions of Expectations) and may allow for dedicated algorithm parametrization and development. ROI (Region of Interest) detection algorithms (in most cases MMO (Man- Made Object) detection) use implicit target and/or background models. The detection algorithms of ROIs utilize gradient direction models that have to be matched with transformed image domain data. In most cases simple threshold calculations on the match results discriminate target object signatures from the background. The geocoding approaches extract line-like structures (street signatures) from the image domain and match the graph constellation against a vector model extracted from a GIS (Geographical Information System) data base. Apart from geo-coding the algorithms can be also used for image-to-image registration (multi sensor and data fusion) and may be used for creation and validation of geographical maps.

  19. Building Background Knowledge within Literature Circles

    ERIC Educational Resources Information Center

    Barone, Diane; Barone, Rebecca

    2012-01-01

    The authors examined the strength of literature circles in developing background knowledge--an acknowledged sticking point in the development of understanding for middle graders--with a special focus on the literature circle role of "investigator," where it is student initiative and not teacher direction that guides comprehension. Observing…

  20. 22 CFR 305.3 - Background investigations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Foreign Relations PEACE CORPS ELIGIBILITY AND STANDARDS FOR PEACE CORPS VOLUNTEER SERVICE § 305.3 Background investigations. Section 22 of the Peace Corps Act states that to ensure enrollment of a Volunteer is consistent with the national interest, no applicant is eligible for Peace Corps Volunteer service...