Science.gov

Sample records for background individual sources

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. Individually Prescribed Instruction: Background Information and Research.

    ERIC Educational Resources Information Center

    DeRenzis, Joseph J.

    The effects of individually prescribed instruction (IPI) in reading as compared to the traditional mode of instruction are examined. The IPI model includes four components: analysis of subject matter content, diagnosis of student preinstructional behavior, sequencing of materials to facilitate learning, and evaluation strategies. Elementary…

  8. Ultraviolet background fluctuations with clustered sources

    NASA Astrophysics Data System (ADS)

    Desjacques, Vincent; Dizgah, Azadeh Moradinezhad; Biagetti, Matteo

    2014-11-01

    We develop a count-in-cells approach to the distribution of ultraviolet background fluctuations that includes source clustering. We demonstrate that an exact expression can be obtained if the clustering of ionizing sources follows the hierarchical ansatz. In this case, the intensity distribution depends solely on their two-point correlation function. We show that the void scaling function of high-redshift mock quasars is consistent with the negative binomial form, before applying our formalism to the description of He II-ionizing fluctuations at the end of helium reionization. The model inputs are the observed quasar luminosity function and two-point correlation at z ˜ 3. We find that, for an (comoving) attenuation length ≲55 Mpc, quasar clustering contributes less than 30 per cent of the variance of intensity fluctuations so long as the quasar correlation length does not exceed ˜15 Mpc. We investigate also the dependence of the intensity distribution on the large-scale environment. Differences in the mean He II-ionizing intensity between low- and high-density regions could be a factor of few if the sources are highly clustered. An accurate description of quasar demographics and their correlation with strong absorption systems is required to make more precise predictions.

  9. Extragalactic sources in Cosmic Microwave Background maps

    SciTech Connect

    Zotti, G. De; Castex, G.; González-Nuevo, J.; Cai, Z.-Y.; Delabrouille, J.; Herranz, D.; Bonavera, L.; Serjeant, S.; Bilicki, M.; Andreani, P. E-mail: gcastex@sissa.it E-mail: marcos.lopez.caniego@sciops.esa.int; and others

    2015-06-01

    We discuss the potential of a next generation space-borne CMB experiment for studies of extragalactic sources with reference to COrE+, a project submitted to ESA in response to the call for a Medium-size mission (M4). We consider three possible options for the telescope size: 1 m, 1.5 m and 2 m (although the last option is probably impractical, given the M4 boundary conditions). The proposed instrument will be far more sensitive than Planck and will have a diffraction-limited angular resolution. These properties imply that even the 1 m telescope option will perform substantially better than Planck for studies of extragalactic sources. The source detection limits as a function of frequency have been estimated by means of realistic simulations taking into account all the relevant foregrounds. Predictions for the various classes of extragalactic sources are based on up-to-date models. The most significant improvements over Planck results are presented for each option. COrE+ will provide much larger samples of truly local star-forming galaxies (by about a factor of 8 for the 1 m telescope, of 17 for 1.5 m, of 30 for 2 m), making possible analyses of the properties of galaxies (luminosity functions, dust mass functions, star formation rate functions, dust temperature distributions, etc.) across the Hubble sequence. Even more interestingly, COrE+ will detect, at |b| > 30°, thousands of strongly gravitationally lensed galaxies (about 2,000, 6,000 and 13,000 for the 1 m, 1.5 m and 2 m options, respectively). Such large samples are of extraordinary astrophysical and cosmological value in many fields. Moreover, COrE+ high frequency maps will be optimally suited to pick up proto-clusters of dusty galaxies, i.e. to investigate the evolution of large scale structure at larger redshifts than can be reached by other means. Thanks to its high sensitivity COrE+ will also yield a spectacular advance in the blind detection of extragalactic sources in polarization: we expect that

  10. Background and Source Term Identification in Active Neutron Interrogation Methods

    DTIC Science & Technology

    2011-03-24

    theory section, ring detector tallies (f5 – MCNP) provided both neutron and photon fluences [particles/cm2] as functions of their energies. Figure 19...BACKGROUND AND SOURCE TERM IDENTIFICATION IN ACTIVE NEUTRON INTERROGATION METHODS THESIS...M01 BACKGROUND AND SOURCE TERM IDENTIFICATION IN ACTIVE NEUTRON INTERROGATION METHODS THESIS Presented to the Faculty Department of

  11. Measurement of background translocation frequencies in individuals with clones

    SciTech Connect

    Wade, Marcelle J.

    1996-08-01

    In the leukemia case the unseparated B and T lymphocytes had a high translocation frequency even after 0.0014, respectively. After purging all clones from the data, the translocation frequencies for Bio 8 and Bio 23 were 0.00750.0014 and 0.0073 metaphases were scored for chromosomal aberrations,, specifically reciprocal translocations, using fluorescence in situ hybridization (FISH). Metaphase spreads were used from two healthy, unexposed individuals (not exposed to radiation, chemotherapy or radiotherapy) and one early B- precursor acute lymphocytic leukemia (ALL) patient (metaphase spreads from both separated T lymphocytes and unseparated B and T lymphocytes were scored). All three individuals had an abnormally high translocation frequency. The high translocation frequencies resulted from clonal expansion of specific translocated chromosomes. I show in this thesis that by purging (discounting or removing) clones from the data of unexposed individuals, one can obtain true background translocation frequencies. In two cases, Bio 8 and Bio 23, the measured translocation frequency for chromosomes 1, 2 and 4 was 0.0124 purging all of the clones from the data. This high translocation frequency may be due to a low frequency of some clones and may not be recognized. The separated T lymphocytes had a higher translocation frequency than expected.

  12. Acculturation: When Individuals and Groups of Different Cultural Backgrounds Meet.

    PubMed

    Sam, David L; Berry, John W

    2010-07-01

    In cross-cultural psychology, one of the major sources of the development and display of human behavior is the contact between cultural populations. Such intercultural contact results in both cultural and psychological changes. At the cultural level, collective activities and social institutions become altered, and at the psychological level, there are changes in an individual's daily behavioral repertoire and sometimes in experienced stress. The two most common research findings at the individual level are that there are large variations in how people acculturate and in how well they adapt to this process. Variations in ways of acculturating have become known by the terms integration, assimilation, separation, and marginalization. Two variations in adaptation have been identified, involving psychological well-being and sociocultural competence. One important finding is that there are relationships between how individuals acculturate and how well they adapt: Often those who integrate (defined as being engaged in both their heritage culture and in the larger society) are better adapted than those who acculturate by orienting themselves to one or the other culture (by way of assimilation or separation) or to neither culture (marginalization). Implications of these findings for policy and program development and for future research are presented. © The Author(s) 2010.

  13. 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.

  14. Background music for repetitive task performance of severely retarded individuals.

    PubMed

    Richman, J S

    1976-11-01

    Environmental manipulation in the form of specific tempo background music was used to assist in the habilitation of severely retarded persons. Thirty institutionalized retarded males were tested on a repetitive manual performance task judged to be similar to the type of tasks found in sheltered workshops. Each subject received each of the background treatments noncontingently: no music, slow tempo music, regular tempo music, fast tempo music. The results indicated that the regular tempo of background music facilitated the greatest improvement in performance, suggesting that the effect of music on performance is more complex than the issue of contingent presentation.

  15. Simulations of background sources in AMoRE-I experiment

    NASA Astrophysics Data System (ADS)

    Luqman, A.; Ha, D. H.; Lee, J. J.; Jeon, E. J.; Jo, H. S.; Kim, H. J.; Kim, Y. D.; Kim, Y. H.; Kobychev, V. V.; Lee, H. S.; Park, H. K.; Siyeon, K.; So, J. H.; Tretyak, V. I.; Yoon, Y. S.

    2017-05-01

    The first phase of the Advanced Mo-based Rare process Experiment (AMoRE-I), an experimental search for neutrinoless double beta decay (0 νββ) of 100Mo in calcium molybdate (40Ca100MoO4) crystal using cryogenic detection techniques, is in preparation at the YangYang underground laboratory (Y2L) in Korea. A GEANT4 based Monte Carlo simulation was performed for the first-phase AMoRE detector and shield configuration. Background sources such as 238U, 232Th, 235U, and 210Pb from inside the crystals, surrounding materials, outer shielding walls of the Y2L cavity were simulated. The estimated background rate in the region of interest was estimated to be < 1.5 ×10-3 counts/keV/kg/yr (ckky). The effects of random coincidences between backgrounds and two-neutrino double beta decays of 100Mo as a potential background source were estimated to be < 2.3 ×10-4 ckky.

  16. Characterization of the radiation background at the Spallation Neutron Source

    NASA Astrophysics Data System (ADS)

    DiJulio, Douglas D.; Cherkashyna, Nataliia; Scherzinger, Julius; Khaplanov, Anton; Pfeiffer, Dorothea; Cooper-Jensen, Carsten P.; Fissum, Kevin G.; Kanaki, Kalliopi; Kirstein, Oliver; Ehlers, Georg; Gallmeier, Franz X.; Hornbach, Donald E.; Iverson, Erik B.; Newby, Robert J.; Hall-Wilton, Richard J.; Bentley, Phillip M.

    2016-09-01

    We present a survey of the radiation background at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory, TN, USA during routine daily operation. A broad range of detectors was used to characterize primarily the neutron and photon fields throughout the facility. These include a WENDI-2 extended range dosimeter, a thermoscientific NRD, an Arktis 4He detector, and a standard NaI photon detector. The information gathered from the detectors was used to map out the neutron dose rates throughout the facility and also the neutron dose rate and flux profiles of several different beamlines. The survey provides detailed information useful for developing future shielding concepts at spallation neutron sources, such as the European Spallation Source (ESS), currently under construction in Lund, Sweden.

  17. Planets as background noise sources in free space optical communications

    NASA Technical Reports Server (NTRS)

    Katz, J.

    1986-01-01

    Background noise generated by planets is the dominant noise source in most deep space direct detection optical communications systems. Earlier approximate analyses of this problem are based on simplified blackbody calculations and can yield results that may be inaccurate by up to an order of magnitude. Various other factors that need to be taken into consideration, such as the phase angle and the actual spectral dependence of the planet albedo, in order to obtain a more accurate estimate of the noise magnitude are examined.

  18. 42 CFR 136.417 - May the IHS hire individuals pending completion of a background investigation?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... HEALTH Indian Child Protection and Family Violence Prevention § 136.417 May the IHS hire individuals... times prior to receipt of the background investigation during which children are in the care of...

  19. 42 CFR 136.417 - May the IHS hire individuals pending completion of a background investigation?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... HEALTH Indian Child Protection and Family Violence Prevention § 136.417 May the IHS hire individuals... times prior to receipt of the background investigation during which children are in the care of...

  20. IDENTIFYING POTENTIAL SOURCES OF BACKGROUND CONTAMINATION IN RT-PCR

    EPA Science Inventory

    Extraction of nucleic acids from low biomass samples, such as drinking water, is particularly sensitive to potential background contamination because the contaminating material is minimally diluted by the sample. The presence of bacterial DNA in Taq DNA polymerase is wel...

  1. IDENTIFYING POTENTIAL SOURCES OF BACKGROUND CONTAMINATION IN RT-PCR

    EPA Science Inventory

    Extraction of nucleic acids from low biomass samples, such as drinking water, is particularly sensitive to potential background contamination because the contaminating material is minimally diluted by the sample. The presence of bacterial DNA in Taq DNA polymerase is wel...

  2. Improvement of individual camouflage through background choice in ground-nesting birds.

    PubMed

    Stevens, Martin; Troscianko, Jolyon; Wilson-Aggarwal, Jared K; Spottiswoode, Claire N

    2017-09-01

    Animal camouflage is a longstanding example of adaptation. Much research has tested how camouflage prevents detection and recognition, largely focusing on changes to an animal's own appearance over evolution. However, animals could also substantially alter their camouflage by behaviourally choosing appropriate substrates. Recent studies suggest that individuals from several animal taxa could select backgrounds or positions to improve concealment. Here, we test whether individual wild animals choose backgrounds in complex environments, and whether this improves camouflage against predator vision. We studied nest site selection by nine species of ground-nesting birds (nightjars, plovers and coursers) in Zambia, and used image analysis and vision modeling to quantify egg and plumage camouflage to predator vision. Individual birds chose backgrounds that enhanced their camouflage, being better matched to their chosen backgrounds than to other potential backgrounds with respect to multiple aspects of camouflage. This occurred at all three spatial scales tested (a few cm and five meters from the nest, and compared to other sites chosen by conspecifics), and was the case for the eggs of all bird groups studied, and for adult nightjar plumage. Thus, individual wild animals improve their camouflage through active background choice, with choices highly refined across multiple spatial scales.

  3. Detection regimes of the cosmological gravitational wave background from astrophysical sources

    NASA Astrophysics Data System (ADS)

    Coward, David; Regimbau, Tania

    2006-09-01

    Key targets for gravitational wave (GW) observatories, such as LIGO and the next generation interferometric detector, Advanced LIGO, include core-collapse of massive stars and the final stage of coalescence of compact stellar remnants. The combined GW signal from such events occurring throughout the Universe will produce an astrophysical GW background (AGB), one that is fundamentally different from the GW background by very early Universe processes. One can classify contributions to the AGB for different classes of sources based on the strength of the GW emissions from the individual sources, their peak emission frequency, emission duration and their event rate density distribution. This article provides an overview of the detectability regimes of the AGB in the context of current and planned gravitational wave observatories. We show that there are two important AGB signal detection regimes, which we define as 'continuous' and 'popcorn noise'. We describe how the 'popcorn noise' AGB regime evolves with observation time and we discuss how this feature distinguishes it from the GW background produced from very early Universe processes.

  4. Is Low Empathy Related to Bullying after Controlling for Individual and Social Background Variables?

    ERIC Educational Resources Information Center

    Jolliffe, Darrick; Farrington, David P.

    2011-01-01

    This paper examines the relationship between low empathy and bullying while also controlling for the impact of a number of other individual and social background variables linked with bullying. This included the relationship to the prevalence of bullying, but also to the frequency and type of bullying. Questionnaires were completed by 720…

  5. Is Low Empathy Related to Bullying after Controlling for Individual and Social Background Variables?

    ERIC Educational Resources Information Center

    Jolliffe, Darrick; Farrington, David P.

    2011-01-01

    This paper examines the relationship between low empathy and bullying while also controlling for the impact of a number of other individual and social background variables linked with bullying. This included the relationship to the prevalence of bullying, but also to the frequency and type of bullying. Questionnaires were completed by 720…

  6. Probing cluster potentials through gravitational lensing of background X-ray sources

    NASA Technical Reports Server (NTRS)

    Refregier, A.; Loeb, A.

    1996-01-01

    The gravitational lensing effect of a foreground galaxy cluster, on the number count statistics of background X-ray sources, was examined. The lensing produces a deficit in the number of resolved sources in a ring close to the critical radius of the cluster. The cluster lens can be used as a natural telescope to study the faint end of the (log N)-(log S) relation for the sources which account for the X-ray background.

  7. Prevalence of long face pattern in Brazilian individuals of different ethnic backgrounds

    PubMed Central

    CARDOSO, Mauricio de Almeida; de CASTRO, Renata Cristina Faria Ribeiro; LI AN, Tien; NORMANDO, David; GARIB, Daniela Gamba; CAPELOZZA FILHO, Leopoldino

    2013-01-01

    Objective: The long face pattern is a facial deformity with increased anterior total facial height due to vertical excess of the lower facial third. Individuals with long face may present different degrees of severity in vertical excess, as well as malocclusions that are difficult to manage. The categorization of vertical excess is useful to determine the treatment prognosis. This survey assessed the distribution of ethnically different individuals with vertical excess according to three levels of severity and determined the prevalence of long face pattern. Material and Methods: The survey was comprised of 5,020 individuals of Brazilian ethnicity (2,480 females and 2,540 males) enrolled in middle schools in Bauru-SP, Brazil. The criterion for inclusion of individuals with vertically impaired facial relationships was based on lip incompetence, evaluated under natural light, in standing natural head position with the lips at rest. Once identified, the individuals were classified into three subtypes according to the severity: mild, moderate, and severe. Then the pooled sample was distributed according to ethnical background as White (Caucasoid), Black (African descent), Brown (mixed descent), Yellow (Asian descent) and Brazilian Indian (Brazilian native descent). The Chi-square (χ2) test was used (p<0.05) to compare the frequency ratios of individuals with vertically impaired facial relationships in the total sample and among different ethnicities, according to the three levels of severity. Results: The severe subtype was rare, except in Black individuals (7.32%), who also presented the highest relative frequency (45.53%) of moderate subtype, followed by Brown individuals (43.40%). In the mild subtype, Yellow (68.08%) and White individuals (62.21%) showed similar and higher relative frequency values. Conclusions: Black individuals had greater prevalence of long face pattern, followed by Brown, White and Yellow individuals. The prevalence of long face pattern was 14

  8. Investigation of background radical sources in a teflon-film irradiation chamber

    SciTech Connect

    Glasson, W.A.; Dunker, A.M. )

    1988-09-01

    In attempts to model hydrocarbon/NOx irradiations carried out in smog chambers, workers have found it necessary to postulate background free radical sources. Without such radical sources, it has not been possible to obtain agreement between the predictions of chemical mechanisms and the chamber data. The background radical sources appear to be specific to chambers and are not used when applying chemical mechanisms to simulate the atmosphere. Until recently, there were no experimental measurements of the radical sources, and as a result assumptions on the nature and magnitude of the sources varied. Differences in these assumptions are responsible for some of the differences in the predictions of chemical mechanisms in atmospheric simulations. Experimental determinations of the background radical sources in different chambers are, therefore, imperative for the effective use of chamber experiments in developing and evaluating chemical mechanisms for smog formation. In this work, they have conducted a detailed study of the background radical sources in a small Teflon-film chamber. The purpose was to determine the usefulness of such chambers for quantitative studies of smog formation. Values for the background radical sources were derived from the experimental data by simulations with a detailed chemical mechanism, and the uncertainties in these values were estimated as well. The effects of various parameters, such as light intensity and NO and NO{sub 2} concentrations, on the radical sources were studied to provide the necessary information for taking these sources into account in modeling future chamber experiments.

  9. Computational Assessment of Naturally Occurring Neutron and Photon Background Radiation Produced by Extraterrestrial Sources

    SciTech Connect

    Miller, Thomas Martin; de Wet, Wouter C.; Patton, Bruce W.

    2015-10-28

    In this study, a computational assessment of the variation in terrestrial neutron and photon background from extraterrestrial sources is presented. The motivation of this assessment is to evaluate the practicality of developing a tool or database to estimate background in real time (or near–real time) during an experimental measurement or to even predict the background for future measurements. The extraterrestrial source focused on during this assessment is naturally occurring galactic cosmic rays (GCRs). The MCNP6 transport code was used to perform the computational assessment. However, the GCR source available in MCNP6 was not used. Rather, models developed and maintained by NASA were used to generate the GCR sources. The largest variation in both neutron and photon background spectra was found to be caused by changes in elevation on Earth's surface, which can be as large as an order of magnitude. All other perturbations produced background variations on the order of a factor of 3 or less. The most interesting finding was that ~80% and 50% of terrestrial background neutrons and photons, respectively, are generated by interactions in Earth's surface and other naturally occurring and man-made objects near a detector of particles from extraterrestrial sources and their progeny created in Earth's atmosphere. In conclusion, this assessment shows that it will be difficult to estimate the terrestrial background from extraterrestrial sources without a good understanding of a detector's surroundings. Therefore, estimating or predicting background during a measurement environment like a mobile random search will be difficult.

  10. MAXIMUM NUMBER OF REPETITIONS, TOTAL WEIGHT LIFTED AND NEUROMUSCULAR FATIGUE IN INDIVIDUALS WITH DIFFERENT TRAINING BACKGROUNDS

    PubMed Central

    Azevedo, Neto R.M.; Julio, U.F.; Andreato, L.V.; Pinto e Silva, C.M.; Hardt, F.; Franchini, E.

    2013-01-01

    The aim of this study was to evaluate the performance, as well as neuromuscular activity, in a strength task in subjects with different training backgrounds. Participants (n = 26) were divided into three groups according to their training backgrounds (aerobic, strength or mixed) and submitted to three sessions: (1) determination of the maximum oxygen uptake during the incremental treadmill test to exhaustion and familiarization of the evaluation of maximum strength (1RM) for the half squat; (2) 1RM determination; and (3) strength exercise, four sets at 80% of the 1RM, in which the maximum number of repetitions (MNR), the total weight lifted (TWL), the root mean square (RMS) and median frequency (MF) of the electromyographic (EMG) activity for the second and last repetition were computed. There was an effect of group for MNR, with the aerobic group performing a higher MNR compared to the strength group (P = 0.045), and an effect on MF with a higher value in the second repetition than in the last repetition (P = 0.016). These results demonstrated that individuals with better aerobic fitness were more fatigue resistant than strength trained individuals. The absence of differences in EMG signals indicates that individuals with different training backgrounds have a similar pattern of motor unit recruitment during a resistance exercise performed until failure, and that the greater capacity to perform the MNR probably can be explained by peripheral adaptations. PMID:24744479

  11. Individual, family background, and contextual explanations of racial and ethnic disparities in youths' exposure to violence.

    PubMed

    Zimmerman, Gregory M; Messner, Steven F

    2013-03-01

    We used data from the Project on Human Development in Chicago Neighborhoods to examine the extent to which individual, family, and contextual factors account for the differential exposure to violence associated with race/ethnicity among youths. Logistic hierarchical item response models on 2344 individuals nested within 80 neighborhoods revealed that the odds of being exposed to violence were 74% and 112% higher for Hispanics and Blacks, respectively, than for Whites. Appreciable portions of the Hispanic-White gap (33%) and the Black-White gap (53%) were accounted for by family background factors, individual differences, and neighborhood factors. The findings imply that programs aimed at addressing the risk factors for exposure to violence and alleviating the effects of exposure to violence may decrease racial/ethnic disparities in exposure to violence and its consequences.

  12. Individual, Family Background, and Contextual Explanations of Racial and Ethnic Disparities in Youths’ Exposure to Violence

    PubMed Central

    Messner, Steven F.

    2013-01-01

    We used data from the Project on Human Development in Chicago Neighborhoods to examine the extent to which individual, family, and contextual factors account for the differential exposure to violence associated with race/ethnicity among youths. Logistic hierarchical item response models on 2344 individuals nested within 80 neighborhoods revealed that the odds of being exposed to violence were 74% and 112% higher for Hispanics and Blacks, respectively, than for Whites. Appreciable portions of the Hispanic–White gap (33%) and the Black–White gap (53%) were accounted for by family background factors, individual differences, and neighborhood factors. The findings imply that programs aimed at addressing the risk factors for exposure to violence and alleviating the effects of exposure to violence may decrease racial/ethnic disparities in exposure to violence and its consequences. PMID:23327266

  13. The relevance of individual genetic background and its role in animal models of epilepsy.

    PubMed

    Schauwecker, P Elyse

    2011-11-01

    Growing evidence has indicated that genetic factors contribute to the etiology of seizure disorders. Most epilepsies are multifactorial, involving a combination of additive and epistatic genetic variables. However, the genetic factors underlying epilepsy have remained unclear, partially due to epilepsy being a clinically and genetically heterogeneous syndrome. Similar to the human situation, genetic background also plays an important role in modulating both seizure susceptibility and its neuropathological consequences in animal models of epilepsy, which has too often been ignored or not been paid enough attention to in published studies. Genetic homogeneity within inbred strains and their general amenability to genetic manipulation have made them an ideal resource for dissecting the physiological function(s) of individual genes. However, the inbreeding that makes inbred mice so useful also results in genetic divergence between them. This genetic divergence is often unaccounted for but may be a confounding factor when comparing studies that have utilized distinct inbred strains. The purpose of this review is to discuss the effects of genetic background strain on epilepsy phenotypes of mice, to remind researchers that the background genetics of a knockout strain can have a profound influence on any observed phenotype, and outline the means by which to overcome potential genetic background effects in experimental models of epilepsy. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Invited article: Characterization of background sources in space-based time-of-flight mass spectrometers.

    PubMed

    Gilbert, J A; Gershman, D J; Gloeckler, G; Lundgren, R A; Zurbuchen, T H; Orlando, T M; McLain, J; von Steiger, R

    2014-09-01

    For instruments that use time-of-flight techniques to measure space plasma, there are common sources of background signals that evidence themselves in the data. The background from these sources may increase the complexity of data analysis and reduce the signal-to-noise response of the instrument, thereby diminishing the science value or usefulness of the data. This paper reviews several sources of background commonly found in time-of-flight mass spectrometers and illustrates their effect in actual data using examples from ACE-SWICS and MESSENGER-FIPS. Sources include penetrating particles and radiation, UV photons, energy straggling and angular scattering, electron stimulated desorption of ions, ion-induced electron emission, accidental coincidence events, and noise signatures from instrument electronics. Data signatures of these sources are shown, as well as mitigation strategies and design considerations for future instruments.

  15. Invited Article: Characterization of background sources in space-based time-of-flight mass spectrometers

    SciTech Connect

    Gilbert, J. A.; Gershman, D. J.; Gloeckler, G.; Lundgren, R. A.; Zurbuchen, T. H.; Orlando, T. M.; McLain, J.; Steiger, R. von

    2014-09-15

    For instruments that use time-of-flight techniques to measure space plasma, there are common sources of background signals that evidence themselves in the data. The background from these sources may increase the complexity of data analysis and reduce the signal-to-noise response of the instrument, thereby diminishing the science value or usefulness of the data. This paper reviews several sources of background commonly found in time-of-flight mass spectrometers and illustrates their effect in actual data using examples from ACE-SWICS and MESSENGER-FIPS. Sources include penetrating particles and radiation, UV photons, energy straggling and angular scattering, electron stimulated desorption of ions, ion-induced electron emission, accidental coincidence events, and noise signatures from instrument electronics. Data signatures of these sources are shown, as well as mitigation strategies and design considerations for future instruments.

  16. Background evaluation for the neutron sources in the Daya Bay experiment

    NASA Astrophysics Data System (ADS)

    Gu, W. Q.; Cao, G. F.; Chen, X. H.; Ji, X. P.; Li, G. S.; Ling, J. J.; Liu, J.; Qian, X.; Wang, W.

    2016-10-01

    We present an evaluation of the background induced by 241Am-13C neutron calibration sources in the Daya Bay reactor neutrino experiment. As a significant background for electron-antineutrino detection at 0.26 ± 0.12 per detector per day on average, it has been estimated by a Monte Carlo simulation that was benchmarked by a special calibration data set. This dedicated data set also provides the energy spectrum of the background.

  17. Background evaluation for the neutron sources in the Daya Bay experiment

    DOE PAGES

    Gu, W. Q.; Cao, G. F.; Chen, X. H.; ...

    2016-07-06

    Here, we present an evaluation of the background induced by 241Am–13C neutron calibration sources in the Daya Bay reactor neutrino experiment. Furthermore, as a significant background for electron-antineutrino detection at 0.26 ± 0.12 detector per day on average, it has been estimated by a Monte Carlo simulation that was benchmarked by a special calibration data set. This dedicated data set also provides the energy spectrum of the background.

  18. Acculturation and other risk factors of depressive disorders in individuals with Turkish migration backgrounds.

    PubMed

    Janssen-Kallenberg, Hanna; Schulz, Holger; Kluge, Ulrike; Strehle, Jens; Wittchen, Hans-Ulrich; Wolfradt, Uwe; Koch-Gromus, Uwe; Heinz, Andreas; Mösko, Mike; Dingoyan, Demet

    2017-07-19

    Acculturation is a long-term, multi-dimensional process occurring when subjects of different cultures stay in continuous contact. Previous studies have suggested that elevated rates of depression among different migrant groups might be due to patterns of acculturation and migration related risk factors. This paper focused on prevalence rates of depressive disorders and related risk factors among individuals with Turkish migration backgrounds. A population-based sample of 662 individuals with Turkish migration backgrounds were interviewed by bilingual interviewers using a standardised diagnostic interview for DSM-IV-TR and ICD-10 diagnoses (CIDI DIA-X Version 2.8). Associations between 12-month prevalence rates of depressive disorders with potential risk factors were assessed, including gender, age, socioeconomic status, acculturation status and migration status. 12-month prevalence rates of any depressive disorder were 29.0%, 14.4% of major depressive disorder (MDD) and 14.7% of dysthymia. Older age and low socioeconomic status were most consistently related to higher risks of depressive disorders. Acculturation status showed associations with subtypes of depressive disorder. Associations differed between men and women. Symptom severity of MDD was linked to gender, with females being more affected by severe symptoms. The prevalence of depressive disorders is high in individuals with Turkish migration backgrounds, which can be partly explained by older age, low socioeconomic status and acculturation pressures. Only a limited number of risk factors were assessed. Acculturation in particular is a complex process which might not be sufficiently represented by the applied measures. Further risk factors have to be identified in representative samples of this migrant group.

  19. Characterization of γ-ray background at IMAT beamline of ISIS Spallation Neutron Source

    NASA Astrophysics Data System (ADS)

    Festa, G.; Andreani, C.; Arcidiacono, L.; Burca, G.; Kockelmann, W.; Minniti, T.; Senesi, R.

    2017-08-01

    The environmental γ -ray background on the IMAT beamline at ISIS Spallation Neutron Source, Target Station 2, is characterized via γ spectroscopy. The measurements include gamma exposure at the imaging detector position, along with the gamma background inside the beamline. Present results are discussed and compared with previous measurements recorded at INES and VESUVIO beamlines operating at Target Station 1. They provide new outcome for expanding and optimizing the PGAA experimental capability at the ISIS neutron source for the investigation of materials, engineering components and cultural heritage objects at the ISIS neutron source.

  20. Common source-multiple load vs. separate source-individual load photovoltaic system

    NASA Technical Reports Server (NTRS)

    Appelbaum, Joseph

    1989-01-01

    A comparison of system performance is made for two possible system setups: (1) individual loads powered by separate solar cell sources; and (2) multiple loads powered by a common solar cell source. A proof for resistive loads is given that shows the advantage of a common source over a separate source photovoltaic system for a large range of loads. For identical loads, both systems perform the same.

  1. Computational Assessment of Naturally Occurring Neutron and Photon Background Radiation Produced by Extraterrestrial Sources

    DOE PAGES

    Miller, Thomas Martin; de Wet, Wouter C.; Patton, Bruce W.

    2015-10-28

    In this study, a computational assessment of the variation in terrestrial neutron and photon background from extraterrestrial sources is presented. The motivation of this assessment is to evaluate the practicality of developing a tool or database to estimate background in real time (or near–real time) during an experimental measurement or to even predict the background for future measurements. The extraterrestrial source focused on during this assessment is naturally occurring galactic cosmic rays (GCRs). The MCNP6 transport code was used to perform the computational assessment. However, the GCR source available in MCNP6 was not used. Rather, models developed and maintained bymore » NASA were used to generate the GCR sources. The largest variation in both neutron and photon background spectra was found to be caused by changes in elevation on Earth's surface, which can be as large as an order of magnitude. All other perturbations produced background variations on the order of a factor of 3 or less. The most interesting finding was that ~80% and 50% of terrestrial background neutrons and photons, respectively, are generated by interactions in Earth's surface and other naturally occurring and man-made objects near a detector of particles from extraterrestrial sources and their progeny created in Earth's atmosphere. In conclusion, this assessment shows that it will be difficult to estimate the terrestrial background from extraterrestrial sources without a good understanding of a detector's surroundings. Therefore, estimating or predicting background during a measurement environment like a mobile random search will be difficult.« less

  2. Ingestion of polonium ((210)Po) via dietary sources in high background radiation areas of south India.

    PubMed

    Arunachalam, Kantha Deivi; Baskaran, Kamesh Viswanathan; Rao, D D; Sathyapriya, R; Annamalai, Sathesh Kumar; Kuruva, Jaya Krishna; Hari, Shanmugamsundaram

    2014-10-01

    To study the distribution of Polonium ((210)Po) activity in dietary sources in the high background radiation zone of Puttetti in southern Tamil Nadu. (210)Po was analyzed in the food materials consumed by the male and female individual representatives living in the high background areas by 24-h Duplicate Diet Study (DDS) and Market Basket Study (MBS). The MBS was performed by collecting the food samples such as, cereals, fruits, leafy vegetables, roots and tubers, other vegetables, fish, meat and milk grown in the high background radiation zone of southern Tamil Nadu as a part of baseline study in this region. The DDS was done by collecting the food materials consumed including the beverages in 24 h from different age groups of male and female individuals living in the village of Puttetti. The intake and ingestion dose of the radionuclide (210)Po was estimated. The average concentration of (210)Po in DDS (n = 33) was found to be 74 mBq.kg(- 1) of fresh weight. The MBS was collected based on food consumption representing more than 85-95% of annual supply, and were divided into eight food groups. The average concentration of (210)Po in the eight food groups namely leafy vegetables was 2176 mBq.kg(- 1) (n = 3), vegetables 55 mBq.kg(- 1) (n = 10), roots and tubers 251 mBq.kg(- 1) (n = 4), fruits 65 mBq.kg(- 1) (n = 5), fish 345 mBq.kg(- 1) (n = 2), meat food 117 mBq.kg(- 1) (n = 3), milk 20 mBq.kg(- 1) (n = 1) and cereal 290 (n = 1) mBq.kg(- 1) of fresh weight, respectively. The annual intake and ingestion dose due to (210)Po was estimated by DDS and MBS in adults, adolescents and children. The overall results showed that the MBS was moderately higher than the DDS in all age groups. Moreover, a DDS approach may even be more realistic, as cooked foodstuffs are used for dietary exposure assessment. The study confirms that the current levels of (210)Po do not pose a significant radiological risk to the local inhabitants.

  3. GOODS-Herschel: identification of the individual galaxies responsible for the 80-290 μm cosmic infrared background

    NASA Astrophysics Data System (ADS)

    Leiton, R.; Elbaz, D.; Okumura, K.; Hwang, H. S.; Magdis, G.; Magnelli, B.; Valtchanov, I.; Dickinson, M.; Béthermin, M.; Schreiber, C.; Charmandaris, V.; Dole, H.; Juneau, S.; Le Borgne, D.; Pannella, M.; Pope, A.; Popesso, P.

    2015-07-01

    Aims: We propose a new method of pushing Herschel to its faintest detection limits using universal trends in the redshift evolution of the far infrared over 24 μm colours in the well-sampled GOODS-North field. An extension to other fields with less multi-wavelength information is presented. This method is applied here to raise the contribution of individually detected Herschel sources to the cosmic infrared background (CIRB) by a factor 5 close to its peak at 250 μm and more than 3 in the 350 and 500 μm bands. Methods: We produce realistic mock Herschel images of the deep PACS and SPIRE images of the GOODS-North field from the GOODS-Herschel key program and use them to quantify the confusion noise at the position of individual sources, i.e., estimate a "local confusion noise". Two methods are used to identify sources with reliable photometric accuracy extracted using 24 μm prior positions. The clean index (CI), previously defined but validated here with simulations, which measures the presence of bright 24 μm neighbours and the photometric accuracy index (PAI) directly extracted from the mock Herschel images. Results: Both methods converge to comparable depths and fractions of the CIRB resolved into sources individually detected with Herschel. After correction for completeness, thanks to our mock Herschel images, individually detected sources make up as much as 54% and 60% of the CIRB in the PACS bands down to 1.1 mJy at 100 μm and 2.2 mJy at 160 μm and 55, 33, and 13% of the CIRB in the SPIRE bands down to 2.5, 5, and 9 mJy at 250 μm, 350 μm, and 500 μm, respectively. The latter depths improve the detection limits of Herschel by factors of 5 at 250 μm, and 3 at 350 μm and 500 μm as compared to the standard confusion limit. Interestingly, the dominant contributors to the CIRB in all Herschel bands appear to be distant siblings of the Milky Way (z ~ 0.96 for λ< 300 μm) with a stellar mass of M⋆ ~ 9 × 1010M⊙.

  4. Is low empathy related to bullying after controlling for individual and social background variables?

    PubMed

    Jolliffe, Darrick; Farrington, David P

    2011-02-01

    This paper examines the relationship between low empathy and bullying while also controlling for the impact of a number of other individual and social background variables linked with bullying. This included the relationship to the prevalence of bullying, but also to the frequency and type of bullying. Questionnaires were completed by 720 adolescents (344 females, 376 males) aged 13-17 in three secondary schools in England. The results suggested that low affective empathy was independently related to bullying by males, but not females. There was no evidence that low cognitive empathy was independently related to bullying, but high impulsivity was related to all forms of male bullying and to female bullying. The implications of the findings for research and practice are discussed. Copyright © 2010 The Association for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  5. Effects of road traffic background noise on judgments of individual airplane noises. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Powell, C. A.

    1979-01-01

    Two laboratory experiments were conducted to investigate the effects of road-traffic background noise on judgments of individual airplane flyover noises. In the first experiment, 27 subjects judged a set of 16 airplane flyover noises in the presence of traffic-noise sessions of 30-min duration consisting of the combinations of 3 traffic-noise types and 3 noise levels. In the second experiment, 24 subjects judged the same airplane flyover noises in the presence of traffic-noise sessions of 10-min duration consisting of the combinations of 2 traffic-noise types and 4 noise levels. In both experiments the airplane noises were judged less annoying in the presence of high traffic-noise levels than in the presence of low traffic-noise levels.

  6. Structure and sources of the sporadic meteor background from video observations

    NASA Astrophysics Data System (ADS)

    Jakšová, Ivana; Porubčan, Vladimír; Klačka, Jozef

    2015-10-01

    We investigate and discuss the structure of the sporadic meteor background population in the near-Earth space based on video meteor orbits from the SonotaCo database (SonotaCo 2009, WGN, 37, 55). The selection of the shower meteors was done by the Southworth-Hawkins streams-search criterion (Southworth & Hawkins 1963, Smithson. Contr. Astrophys., 7, 261). Of a total of 117786 orbits, 69.34% were assigned to sporadic background meteors. Our analysis revealed all the known sporadic sources, such as the dominant apex source which is splitting into the northern and southern branch. Part of a denser ring structure about the apex source connecting the antihelion and north toroidal sources is also evident. We showed that the annual activity of the apex source is similar to the annual variation in activity of the whole sporadic background. The antihelion source exhibits a very broad maximum from July until January and the north toroidal source shows three maxima similar to the radar observations by the Canadian Meteor Orbit Radar (CMOR). Potential parent bodies of the sporadic population were searched for by comparison of the distributions of the orbital elements of sporadic meteors, minor planets and comets.

  7. Determining the Intensity of a Point-Like Source Observed on the Background of AN Extended Source

    NASA Astrophysics Data System (ADS)

    Kornienko, Y. V.; Skuratovskiy, S. I.

    2014-12-01

    The problem of determining the time dependence of intensity of a point-like source in case of atmospheric blur is formulated and solved by using the Bayesian statistical approach. A pointlike source is supposed to be observed on the background of an extended source with constant in time though unknown brightness. The equation system for optimal statistical estimation of the sequence of intensity values in observation moments is obtained. The problem is particularly relevant for studying gravitational mirages which appear while observing a quasar through the gravitational field of a far galaxy.

  8. Health care reform: understanding individuals' attitudes and information sources.

    PubMed

    Shue, Carolyn K; McGeary, Kerry Anne; Reid, Ian; Khubchandani, Jagdish; Fan, Maoyong

    2014-01-01

    Since passage of the Affordable Care Act (ACA) was signed into law by President Barrack Obama, little is known about state-level perceptions of residents on the ACA. Perceptions about the act could potentially affect implementation of the law to the fullest extent. This 3-year survey study explored attitudes about the ACA, the types of information sources that individuals rely on when creating those attitudes, and the predictors of these attitudes among state of Indiana residents. The respondents were split between favorable and unfavorable views of the ACA, yet the majority of respondents strongly supported individual components of the act. National TV news, websites, family members, and individuals' own reading of the ACA legislation were identified as the most influential information sources. After controlling for potential confounders, the respondent's political affiliation, age, sex, and obtaining ACA information from watching national television news were the most important predictors of attitudes about the ACA and its components. These results mirror national-level findings. Implications for implementing health care reform at the state-level are discussed.

  9. Health Care Reform: Understanding Individuals' Attitudes and Information Sources

    PubMed Central

    Shue, Carolyn K.; McGeary, Kerry Anne; Reid, Ian; Fan, Maoyong

    2014-01-01

    Since passage of the Affordable Care Act (ACA) was signed into law by President Barrack Obama, little is known about state-level perceptions of residents on the ACA. Perceptions about the act could potentially affect implementation of the law to the fullest extent. This 3-year survey study explored attitudes about the ACA, the types of information sources that individuals rely on when creating those attitudes, and the predictors of these attitudes among state of Indiana residents. The respondents were split between favorable and unfavorable views of the ACA, yet the majority of respondents strongly supported individual components of the act. National TV news, websites, family members, and individuals' own reading of the ACA legislation were identified as the most influential information sources. After controlling for potential confounders, the respondent's political affiliation, age, sex, and obtaining ACA information from watching national television news were the most important predictors of attitudes about the ACA and its components. These results mirror national-level findings. Implications for implementing health care reform at the state-level are discussed. PMID:25045705

  10. Output of acoustical sources. [effects of structural elements and background flow on immobile multipolar point radiation

    NASA Technical Reports Server (NTRS)

    Levine, H.

    1980-01-01

    Acoustic radiation from a source, here viewed as an immobile point singularity with periodic strength and a given multipolar nature, is affected by the presence of nearly structural elements (e.g., rigid or impedance surfaces) as well as that of a background flow in the medium. An alternative to the conventional manner of calculating the net source output by integrating the energy flux over a distant control surface is described; this involves a direct evaluation of the secondary wavefunction at the position of the primary source and obviates the need for a (prospectively difficult) flux integration. Various full and half-planar surface configurations with an adjacent source are analyzed in detail, and the explicit results obtained, in particular, for the power factor of a dipole brings out a substantial rise in its output as the source nears the sharp edge of a half-plane.

  11. Output of acoustical sources. [effects of structural elements and background flow on immobile multipolar point radiation

    NASA Technical Reports Server (NTRS)

    Levine, H.

    1980-01-01

    Acoustic radiation from a source, here viewed as an immobile point singularity with periodic strength and a given multipolar nature, is affected by the presence of nearly structural elements (e.g., rigid or impedance surfaces) as well as that of a background flow in the medium. An alternative to the conventional manner of calculating the net source output by integrating the energy flux over a distant control surface is described; this involves a direct evaluation of the secondary wavefunction at the position of the primary source and obviates the need for a (prospectively difficult) flux integration. Various full and half-planar surface configurations with an adjacent source are analyzed in detail, and the explicit results obtained, in particular, for the power factor of a dipole brings out a substantial rise in its output as the source nears the sharp edge of a half-plane.

  12. On syntheses of the X-ray background with power-law sources

    NASA Technical Reports Server (NTRS)

    Dezotti, G.; Boldt, E. A.; Cavaliere, A.; Danese, L.; Franceschini, A.; Marshall, F. E.; Swank, J. H.; Szymkowiak, A. E.

    1981-01-01

    The conditions under which the combined emission from power law sources can mimic the X-ray background (XRB) spectrum in the 3-50 keV range are considered in view of HEAO 1 A-2 experiment measurements, and it is confirmed that a good fit may be obtained. The required spectral properties of the component sources differ, however, from those observed for local active galactic nuclei. Constraints are deduced for both the low luminosity extension and evolution of such local objects, and it is shown that any other class of sources contributing to the X-ray background must be characterized by an energy spectral index lower than about 0.4, which is the mean index of the XRB, and exhibit sleeper spectra at higher energies.

  13. On syntheses of the X-ray background with power-law sources

    NASA Technical Reports Server (NTRS)

    De Zotti, G.; Boldt, E. A.; Marshall, F. E.; Swank, J. H.; Szymkowiak, A. E.; Cavaliere, A.; Danese, L.; Franceschini, A.

    1982-01-01

    The conditions under which the combined emission from power-law sources can mimic the X-ray background (XRB) spectrum in the 3-50 keV range are considered in view of HEAO 1 A-2 experiment measurements, and it is confirmed that a good fit may be obtained. The required spectral properties of the component sources differ, however, from those observed for local active galactic nuclei. Constraints are deduced for both the low-luminosity extension and evolution of such local objects, and it is shown that any other class of sources contributing to the X-ray background must be characterized by an energy spectral index lower than about 0.4, which is the mean index of the XRB, and exhibit steeper spectra at higher energies.

  14. Source apportionment of the summer time carbonaceous aerosol at Nordic rural background sites

    NASA Astrophysics Data System (ADS)

    Yttri, K. E.; Simpson, D.; Nøjgaard, J. K.; Kristensen, K.; Genberg, J.; Stenström, K.; Swietlicki, E.; Hillamo, R.; Aurela, M.; Bauer, H.; Offenberg, J. H.; Jaoui, M.; Dye, C.; Eckhardt, S.; Burkhart, J. F.; Stohl, A.; Glasius, M.

    2011-06-01

    In the present study, natural and anthropogenic sources of particulate organic carbon (OCp) and elemental carbon (EC) have been quantified based on weekly filter samples of PM10 collected at four Nordic rural background sites (Birkenes (Norway), Hyytiälä (Finland) Vavihill (Sweden), Lille Valby (Denmark)) during late summer (5 August-2 September 2009). Levels of source specific tracers, i.e. cellulose, levoglucosan, mannitol and the 14C/12C ratio of total carbon (TC), have been used as input for source apportionment of the carbonaceous aerosol, whereas Latin Hypercube Sampling (LHS) was used to statistically treat the multitude of possible combinations resulting from this approach. The carbonaceous aerosol (here: TCp; i.e. particulate TC) was totally dominated by natural sources (69-86 %), with biogenic secondary organic aerosol (BSOA) being the single most important source (48-57 %). Interestingly, primary biological aerosol particles (PBAP) were the second most important source (20-32 %). The anthropogenic contribution was mainly attributed to fossil fuel sources (OCff and ECff (10-24 %), whereas no more than 3-7 % was explained by combustion of biomass (OCbb and ECbb in this late summer campaign i.e. emissions from residential wood burning and/or wild/agricultural fires. Fossil fuel sources totally dominated the ambient EC loading, accounting for 4-12 % of TCp, whereas <1.5 % was attributed to combustion of biomass. The carbonaceous aerosol source apportionment showed only minor variation between the four selected sites. However, Hyytiälä and Birkenes showed greater resemblance to each other, as did Lille Valby and Vavihill, the two latter being somewhat more influenced by anthropogenic sources. Ambient levels of organosulphates and nitrooxy-organosulphates in the Nordic rural background environment are reported for the first time in the present study. The most abundant organosulphate compounds were an organosulphate of isoprene and nitrooxy

  15. THE NEXT GENERATION VIRGO CLUSTER SURVEY. XV. THE PHOTOMETRIC REDSHIFT ESTIMATION FOR BACKGROUND SOURCES

    SciTech Connect

    Raichoor, A.; Mei, S.; Huertas-Company, M.; Licitra, R.; Erben, T.; Hildebrandt, H.; Ilbert, O.; Boissier, S.; Boselli, A.; Ball, N. M.; Côté, P.; Ferrarese, L.; Gwyn, S. D. J.; Kavelaars, J. J.; Chen, Y.-T.; Cuillandre, J.-C.; Duc, P. A.; Guhathakurta, P.; and others

    2014-12-20

    The Next Generation Virgo Cluster Survey (NGVS) is an optical imaging survey covering 104 deg{sup 2} centered on the Virgo cluster. Currently, the complete survey area has been observed in the u*giz bands and one third in the r band. We present the photometric redshift estimation for the NGVS background sources. After a dedicated data reduction, we perform accurate photometry, with special attention to precise color measurements through point-spread function homogenization. We then estimate the photometric redshifts with the Le Phare and BPZ codes. We add a new prior that extends to i {sub AB} = 12.5 mag. When using the u* griz bands, our photometric redshifts for 15.5 mag ≤ i ≲ 23 mag or z {sub phot} ≲ 1 galaxies have a bias |Δz| < 0.02, less than 5% outliers, a scatter σ{sub outl.rej.}, and an individual error on z {sub phot} that increases with magnitude (from 0.02 to 0.05 and from 0.03 to 0.10, respectively). When using the u*giz bands over the same magnitude and redshift range, the lack of the r band increases the uncertainties in the 0.3 ≲ z {sub phot} ≲ 0.8 range (–0.05 < Δz < –0.02, σ{sub outl.rej} ∼ 0.06, 10%-15% outliers, and z {sub phot.err.} ∼ 0.15). We also present a joint analysis of the photometric redshift accuracy as a function of redshift and magnitude. We assess the quality of our photometric redshifts by comparison to spectroscopic samples and by verifying that the angular auto- and cross-correlation function w(θ) of the entire NGVS photometric redshift sample across redshift bins is in agreement with the expectations.

  16. The Next Generation Virgo Cluster Survey. XV. The Photometric Redshift Estimation for Background Sources

    NASA Astrophysics Data System (ADS)

    Raichoor, A.; Mei, S.; Erben, T.; Hildebrandt, H.; Huertas-Company, M.; Ilbert, O.; Licitra, R.; Ball, N. M.; Boissier, S.; Boselli, A.; Chen, Y.-T.; Côté, P.; Cuillandre, J.-C.; Duc, P. A.; Durrell, P. R.; Ferrarese, L.; Guhathakurta, P.; Gwyn, S. D. J.; Kavelaars, J. J.; Lançon, A.; Liu, C.; MacArthur, L. A.; Muller, M.; Muñoz, R. P.; Peng, E. W.; Puzia, T. H.; Sawicki, M.; Toloba, E.; Van Waerbeke, L.; Woods, D.; Zhang, H.

    2014-12-01

    The Next Generation Virgo Cluster Survey (NGVS) is an optical imaging survey covering 104 deg2 centered on the Virgo cluster. Currently, the complete survey area has been observed in the u*giz bands and one third in the r band. We present the photometric redshift estimation for the NGVS background sources. After a dedicated data reduction, we perform accurate photometry, with special attention to precise color measurements through point-spread function homogenization. We then estimate the photometric redshifts with the Le Phare and BPZ codes. We add a new prior that extends to i AB = 12.5 mag. When using the u* griz bands, our photometric redshifts for 15.5 mag <= i <~ 23 mag or z phot <~ 1 galaxies have a bias |Δz| < 0.02, less than 5% outliers, a scatter σoutl.rej., and an individual error on z phot that increases with magnitude (from 0.02 to 0.05 and from 0.03 to 0.10, respectively). When using the u*giz bands over the same magnitude and redshift range, the lack of the r band increases the uncertainties in the 0.3 <~ z phot <~ 0.8 range (-0.05 < Δz < -0.02, σoutl.rej ~ 0.06, 10%-15% outliers, and z phot.err. ~ 0.15). We also present a joint analysis of the photometric redshift accuracy as a function of redshift and magnitude. We assess the quality of our photometric redshifts by comparison to spectroscopic samples and by verifying that the angular auto- and cross-correlation function w(θ) of the entire NGVS photometric redshift sample across redshift bins is in agreement with the expectations.

  17. Psittacine cognition: Individual differences and sources of variation.

    PubMed

    Cussen, Victoria A

    2017-01-01

    Both the number and breadth of avian cognition studies have expanded in the past three decades. Parrots have a long history as subjects in avian cognition research. This paper summarizes results from a number of parrot species tested on basic learning, and physical & social cognitive processes, with an emphasis on individual differences. Early psittacine studies were aimed at demonstrating a particular cognitive ability existed in a given species. Because of this proof of capacity focus, early studies typically included only a single individual or a dyad of parrots. Existing reviews of parrot cognition tend to focus on a particular cognitive component in a single species, or even a single individual. Despite the narrow focus, results from increasing sample sizes show intraspecific variation across a variety of cognitive assessments and parrot species. Intraspecific variability in performance on cognitive tasks highlights the need for establishing a cognitive normal range for a given species and process. To accomplish this, large numbers of individuals need to be tested and non-cognitive sources of variability need to be controlled. Once species typical cognitive normal ranges are established, cognitive comparisons can be made between parrot species and between parrots and other taxa.

  18. Levels and potential sources of atmospheric organochlorine pesticides at Korea background sites

    NASA Astrophysics Data System (ADS)

    Jin, Guang-Zhu; Kim, Sang-Min; Lee, Su-Yeong; Park, Jin-Soo; Kim, Dong-Hoon; Lee, Min-Jin; Sim, Ki-Tae; Kang, Hak-Gu; Kim, Il-Gyu; Shin, Sun-Kyoung; Seok, Kwang-Seol; Hwang, Seung-Ryul

    2013-04-01

    Data are presented for 11 organochlorine pesticides (OCPs) measured by high volume air samplers at three background sites (monthly for one site, seasonally for two sites) in South Korea during June 2008 and December 2009, and levels, seasonal variations and potential sources of high levels of OCPs and impact of long-range transport (LRT) were discussed. Geometric mean (GM) concentrations of OCPs in air samples (pg m-3) were highest for HCB (80, 15.0-256), HCH (71, 10.8-547), a currently used pesticide, DDT (3.50, ND-56.5), and Chlordane (1.15, ND-10.5). Other chemicals regularly detected included, Heptachlor (0.41, ND-2.59), Drins (0.61, ND-4.36) and Mirex (0.04, ND-0.78). Seasonal variation of OCPs was featured by higher concentrations in summer and lower in winter period. This could be associated with their temperature-driven re-volatilization from historical source and recent application of some OCPs (such as dicofol, HCH etc). Ratios of specific OCPs isomers suggest that dominant source of air HCHs in Korea background sites is technical HCH with a little input of lindane in recent time, and dominant source of air DDT is old and used technical DDT with a little bit of dicofol type DDT, and current air chlordane in Korean background sites mainly come from the source of historically used chlordane. The results from this study will provide comparable and scientifically sound data of OCP in background air and will contribute to further long-term POPs monitoring program in East Asia.

  19. Comparing Imaging and Non-Imaging Techniques for Reducing Background Clutter and Resolving Distant Point Sources

    SciTech Connect

    Wurtz, R; Ziock, K; Fabris, L; Graham, R

    2005-11-10

    To reach maximum sensitivity, any method used to search for orphan sources must be insensitive to local variations of the background. Using imaging and non-imaging techniques, we analyzed the same data acquired by a search instrument deployed as a large-area, coded-mask imager. Data from many passes past a 1 mCi source at 65 m from the instrument were used to construct a model of the instrument response. We then used the model to ''hide'' the source in data taken in a light urban environment. We compared the success of detecting the hidden sources using imaging coded-mask methods, pseudo-imaging based on a zero-area matched filter, and non-imaging using simple thresholding. The results clearly indicate the superiority of imaging with the coded-mask techniques returning the best results.

  20. Phonological awareness and short-term memory in hearing and deaf individuals of different communication backgrounds.

    PubMed

    Koo, Daniel; Crain, Kelly; LaSasso, Carol; Eden, Guinevere F

    2008-12-01

    Previous work in deaf populations on phonological coding and working memory, two skills thought to play an important role in the acquisition of written language skills, have focused primarily on signers or did not clearly identify the subjects' native language and communication mode. In the present study, we examined the effect of sensory experience, early language experience, and communication mode on the phonological awareness skills and serial recall of linguistic items in deaf and hearing individuals of different communicative and linguistic backgrounds: hearing nonsigning controls, hearing users of ASL, deaf users of ASL, deaf oral users of English, and deaf users of cued speech. Since many current measures of phonological awareness skills are inappropriate for deaf populations on account of the verbal demands in the stimuli or response, we devised a nonverbal phonological measure that addresses this limitation. The Phoneme Detection Test revealed that deaf cuers and oral users, but not deaf signers, performed as well as their hearing peers when detecting phonemes not transparent in the orthography. The second focus of the study examined short-term memory skills and found that in response to the traditional digit span as well as an experimental visual version, digit-span performance was similar across the three deaf groups, yet deaf subjects' retrieval was lower than that of hearing subjects. Our results support the claim (Bavelier et al., 2006) that lexical items processed in the visual-spatial modality are not as well retained as information processed in the auditory channel. Together these findings show that the relationship between working memory, phonological coding, and reading may not be as tightly interwoven in deaf students as would have been predicted from work conducted in hearing students.

  1. Background studies for the COHERENT experiment at the Spallation Neutron Source

    NASA Astrophysics Data System (ADS)

    Markoff, Diane M.; COHERENT Collaboration

    2017-09-01

    The COHERENT experiment is designed for a first measurement and N2 dependence study of coherent elastic neutrino-nucleus scattering (CEvNS) at the Oak Ridge Spallation Neutron Source (SNS). CEvNS is a standard model process that is important in understanding supernova neutrinos, the structure of the weak interaction and backgrounds for dark matter searches. The COHERENT collaboration is placing a suite of detector technologies in a basement location at the SNS: 14 kg CsI[Na] crystals; 185 kg NaI crystals; 35 kg single-phase LAr; 10kg high-purity, point contact Ge. Previous attempts to measure the CEvNS process have grappled with very high background rates. One class of troublesome backgrounds is accelerator-correlated neutrons because a simple accelerator on/off background subtraction procedure fails to remove these events. The collaboration has completed a comprehensive background study in the basement region where the experiments are located. We conclude from these studies that the neutron background is sufficiently low for successful CEvNS measurement in the SNS basement region. Neutron measurements from the Indiana University SciBath detector and the Sandia Neutron Scatter Camera are presented here.

  2. Portuguese Coaches’ Perceptions of and Preferences for Knowledge Sources Related to their Professional Background

    PubMed Central

    Mesquita, Isabel; Isidro, Sofia; Rosado, António

    2010-01-01

    The purpose of this study was to analyse Portuguese coaches’ perceptions of, and preferences for, knowledge sources as related to professional background; namely academic education level, coach education level and coaching experience. The study’s participants comprised 336 Portuguese coaches from twenty-two sports. A questionnaire was used to identify coaches’ demographic characteristics and representations about their preferred sources of coaching knowledge. MANOVA using Tukey’s HSD test was used to compare groups. The results highlighted that coaches perceived that coaching knowledge is built from a broad range of sources from personal coaching and playing experiences to more explicit formal, informal and non-formal learning situations. Results indicated that the coaches ascribed more importance to experiential sources such as working with experts, learning by doing, interacting with peer coaches and attending informal seminars and clinics, than to the formal learning situations provided by the national coaching certification programs. Differences, however, were found in that coaches who had a greater background within higher education (physical) and sport valued informal and non-formal learning sources more than did coaches who were defined as not coming from an academic background. The findings point to the importance of developing new learning, experientially-based, opportunities within the Portuguese context, where curricula content continues to be delivered via didactic means. Key points Coaches recognized that learning is obtained from a broad range of sources of coaching knowledge and each source has a particular role in the development of a coach. Experiential guided sources reached more importance to coaches as working with experts, learning by doing, attending seminars/clinics outside of the formal system and interaction with peers were the most acknowledged. The only source that is related to formal learning, national certification programs

  3. Systematic investigation of background sources in neutron flux measurements with a proton-recoil silicon detector

    NASA Astrophysics Data System (ADS)

    Marini, P.; Mathieu, L.; Acosta, L.; Aïche, M.; Czajkowski, S.; Jurado, B.; Tsekhanovich, I.

    2017-01-01

    Proton-recoil detectors (PRDs), based on the well known standard H(n,p) elastic scattering cross section, are the preferred instruments to perform precise quasi-absolute neutron flux measurements above 1 MeV. The limitations of using a single silicon detector as PRD at a continuous neutron beam facility are investigated, with the aim of extending such measurements to neutron energies below 1 MeV. This requires a systematic investigation of the background sources affecting the neutron flux measurement. Experiments have been carried out at the AIFIRA facility to identify these sources. A study on the role of the silicon detector thickness on the background is presented and an energy limit on the use of a single silicon detector to achieve a neutron flux precision better than 1% is given.

  4. Chemical Source Localization Fusing Concentration Information in the Presence of Chemical Background Noise.

    PubMed

    Pomareda, Víctor; Magrans, Rudys; Jiménez-Soto, Juan M; Martínez, Dani; Tresánchez, Marcel; Burgués, Javier; Palacín, Jordi; Marco, Santiago

    2017-04-20

    We present the estimation of a likelihood map for the location of the source of a chemical plume dispersed under atmospheric turbulence under uniform wind conditions. The main contribution of this work is to extend previous proposals based on Bayesian inference with binary detections to the use of concentration information while at the same time being robust against the presence of background chemical noise. For that, the algorithm builds a background model with robust statistics measurements to assess the posterior probability that a given chemical concentration reading comes from the background or from a source emitting at a distance with a specific release rate. In addition, our algorithm allows multiple mobile gas sensors to be used. Ten realistic simulations and ten real data experiments are used for evaluation purposes. For the simulations, we have supposed that sensors are mounted on cars which do not have among its main tasks navigating toward the source. To collect the real dataset, a special arena with induced wind is built, and an autonomous vehicle equipped with several sensors, including a photo ionization detector (PID) for sensing chemical concentration, is used. Simulation results show that our algorithm, provides a better estimation of the source location even for a low background level that benefits the performance of binary version. The improvement is clear for the synthetic data while for real data the estimation is only slightly better, probably because our exploration arena is not able to provide uniform wind conditions. Finally, an estimation of the computational cost of the algorithmic proposal is presented.

  5. RESULTS OF BACKGROUND SUBTRACTION TECHNIQUES ON THE SPALLATION NEUTRON SOURCE BEAM LOSS MONITORS

    SciTech Connect

    Pogge, James R; Zhukov, Alexander P

    2010-01-01

    Recent improvements to the Spallation Neutron Source (SNS) beam loss monitor (BLM) designs have been made with the goal of significantly reducing background noise. This paper outlines this effort and analyzes the results. The significance of this noise reduction is the ability to use the BLM sensors [1], [2], [3] distributed throughout the SNS accelerator as a method to monitor activation of components as well as monitor beam losses.

  6. Chemical Source Localization Fusing Concentration Information in the Presence of Chemical Background Noise †

    PubMed Central

    Pomareda, Víctor; Magrans, Rudys; Jiménez-Soto, Juan M.; Martínez, Dani; Tresánchez, Marcel; Burgués, Javier; Palacín, Jordi; Marco, Santiago

    2017-01-01

    We present the estimation of a likelihood map for the location of the source of a chemical plume dispersed under atmospheric turbulence under uniform wind conditions. The main contribution of this work is to extend previous proposals based on Bayesian inference with binary detections to the use of concentration information while at the same time being robust against the presence of background chemical noise. For that, the algorithm builds a background model with robust statistics measurements to assess the posterior probability that a given chemical concentration reading comes from the background or from a source emitting at a distance with a specific release rate. In addition, our algorithm allows multiple mobile gas sensors to be used. Ten realistic simulations and ten real data experiments are used for evaluation purposes. For the simulations, we have supposed that sensors are mounted on cars which do not have among its main tasks navigating toward the source. To collect the real dataset, a special arena with induced wind is built, and an autonomous vehicle equipped with several sensors, including a photo ionization detector (PID) for sensing chemical concentration, is used. Simulation results show that our algorithm, provides a better estimation of the source location even for a low background level that benefits the performance of binary version. The improvement is clear for the synthetic data while for real data the estimation is only slightly better, probably because our exploration arena is not able to provide uniform wind conditions. Finally, an estimation of the computational cost of the algorithmic proposal is presented. PMID:28425926

  7. On the source function of the soft X-ray diffuse background

    NASA Technical Reports Server (NTRS)

    Burrows, David N.; Kraft, Ralph P.

    1993-01-01

    Radiation transfer theory has been used recently to derive the source function of the soft X-ray diffuse background, resulting in the claim of evidence for 10 exp 6 K gas in the Galactic halo. We show that this analysis has several errors that invalidate its conclusions. We argue that the case for an extensive hot halo remains open, pending further work, but may be settled by the continuing series of Rosat observations of high-latitude soft X-ray shadows.

  8. A novel multifrequency technique for the detection of point sources in cosmic microwave background maps

    NASA Astrophysics Data System (ADS)

    Herranz, D.; López-Caniego, M.; Sanz, J. L.; González-Nuevo, J.

    2009-03-01

    In this work we address the problem of simultaneous multifrequency detection of extragalactic point sources in the maps of the cosmic microwave background. We apply a new linear filtering technique, the `matched matrix filters', that incorporates full spatial information, including the cross-correlation among channels, without making any a priori assumption about the spectral behaviour of the sources. A substantial reduction of the background is achieved thanks to the optimal combination of filtered maps. We describe the new technique in detail and apply it to the detection of radio sources and estimation of their parameters in realistic all-sky Planck simulations at 30, 44, 70 and 100 GHz. Then, we compare the results with the single-frequency approach based on the standard matched filter, in terms of reliability, completeness and flux accuracy of the resulting point source catalogues. The new filters outperform the standard matched filters for all these indexes at 30, 44 and 70 GHz, whereas at 100 GHz both kinds of filters have a similar performance. We find a notable increment of the number of true detections for a fixed reliability level. In particular, for a 95 per cent reliability we practically double the number of detections at 30, 44 and 70 GHz.

  9. Background Studies at the Spallation Neutron Source for the COHERENT Experiment

    NASA Astrophysics Data System (ADS)

    Heath, Matthew; Coherent Collaboration

    2016-09-01

    The COHERENT experiment is attempting a first measurement of coherent elastic neutrino-nucleus scattering (CEvNS) at the Spallation Neutron Source (SNS) at Oak Ridge National Lab. CEvNS is a standard model process that is important in understanding supernova neutrinos, the structure of the weak interaction, and as a background for dark matter searches. COHERENT is placing a suite of four detector technologies in a basement location at the SNS: point contact germanium detectors, CsI[Na] crystals, NaI[Tl] crystals, and single phase liquid argon. Previous attempts to measure the CEvNS process have grappled with very high rates of backgrounds due to the low energy thresholds required. Accelerator-correlated neutrons are the most troublesome background for COHERENT because a simple accelerator on/off background subtraction procedure fails to remove them. To understand these backgrounds, COHERENT features measurements from the SciBath detector and the Sandia Neutron Scatter Camera (NSC). Important neutron measurements from both SciBath and the NSC, as well as gamma measurements from the SNS basement location where the four detector technologies for COHERENT will be placed will be discussed. COHERENT collaborators are supported by the U. S. Department of Energy Office of Science, the National Science Foundation, NASA, and the Sloan Foundation.

  10. The Ultraluminous X-Ray Source X-37 Is a Background Quasar in the Antennae Galaxies

    NASA Astrophysics Data System (ADS)

    Clark, D. M.; Christopher, M. H.; Eikenberry, S. S.; Brandl, B. R.; Wilson, J. C.; Carson, J. C.; Henderson, C. P.; Hayward, T. L.; Barry, D. J.; Ptak, A. F.; Colbert, E. J. M.

    2005-10-01

    In this Letter we report that a bright, X-ray source in the Antennae galaxies (NGC 4038/9), previously identified as an ultraluminous X-ray source (ULX), is in fact a background quasar. We identify an isolated infrared and optical counterpart within 0.3" +/- 0.5" of the X-ray source X-37. After acquiring an optical spectrum of its counterpart, we use the narrow [O III] and broad Hα emission lines to identify X-37 as a quasar at a redshift of z=0.26. Through a U, V, and Ks photometric analysis, we demonstrate that most of the observable light along this line of sight is from the quasar. We discuss the implications of this discovery and the importance of acquiring spectra for optical and IR counterparts to ULXs.

  11. Conditioning Individual Mosquitoes to an Odor: Sex, Source, and Time

    PubMed Central

    Sanford, Michelle R.; Tomberlin, Jeffery K.

    2011-01-01

    Olfactory conditioning of mosquitoes may have important implications for vector-pathogen-host dynamics. If mosquitoes learn about specific host attributes associated with pathogen infection, it may help to explain the heterogeneity of biting and disease patterns observed in the field. Sugar-feeding is a requirement for survival in both male and female mosquitoes. It provides a starting point for learning research in mosquitoes that avoids the confounding factors associated with the observer being a potential blood-host and has the capability to address certain areas of close-range mosquito learning behavior that have not previously been described. This study was designed to investigate the ability of the southern house mosquito, Culex quinquefasciatus Say to associate odor with a sugar-meal with emphasis on important experimental considerations of mosquito age (1.2 d old and 3–5 d old), sex (male and female), source (laboratory and wild), and the time between conditioning and testing (<5 min, 1 hr, 2.5 hr, 5 hr, 10 hr, and 24 hr). Mosquitoes were individually conditioned to an odor across these different experimental conditions. Details of the conditioning protocol are presented as well as the use of binary logistic regression to analyze the complex dataset generated from this experimental design. The results suggest that each of the experimental factors may be important in different ways. Both the source of the mosquitoes and sex of the mosquitoes had significant effects on conditioned responses. The largest effect on conditioning was observed in the lack of positive response following conditioning for females aged 3–5 d derived from a long established colony. Overall, this study provides a method for conditioning experiments involving individual mosquitoes at close range and provides for future discussion of the relevance and broader questions that can be asked of olfactory conditioning in mosquitoes. PMID:21887384

  12. Source apportionment of the summer time carbonaceous aerosol at Nordic rural background sites

    NASA Astrophysics Data System (ADS)

    Yttri, K. E.; Simpson, D.; Nøjgaard, J. K.; Kristensen, K.; Genberg, J.; Stenström, K.; Swietlicki, E.; Hillamo, R.; Aurela, M.; Bauer, H.; Offenberg, J. H.; Jaoui, M.; Dye, C.; Eckhardt, S.; Burkhart, J. F.; Stohl, A.; Glasius, M.

    2011-12-01

    In the present study, natural and anthropogenic sources of particulate organic carbon (OCp) and elemental carbon (EC) have been quantified based on weekly filter samples of PM10 (particles with aerodynamic diameter <10 μm) collected at four Nordic rural background sites [Birkenes (Norway), Hyytiälä (Finland), Vavihill (Sweden), Lille Valby, (Denmark)] during late summer (5 August-2 September 2009). Levels of source specific tracers, i.e. cellulose, levoglucosan, mannitol and the 14C/12C ratio of total carbon (TC), have been used as input for source apportionment of the carbonaceous aerosol, whereas Latin Hypercube Sampling (LHS) was used to statistically treat the multitude of possible combinations resulting from this approach. The carbonaceous aerosol (here: TCp; i.e. particulate TC) was totally dominated by natural sources (69-86%), with biogenic secondary organic aerosol (BSOA) being the single most important source (48-57%). Interestingly, primary biological aerosol particles (PBAP) were the second most important source (20-32%). The anthropogenic contribution was mainly attributed to fossil fuel sources (OCff and ECff) (10-24%), whereas no more than 3-7% was explained by combustion of biomass (OCbb and ECbb) in this late summer campaign i.e. emissions from residential wood burning and/or wild/agricultural fires. Fossil fuel sources totally dominated the ambient EC loading, which accounted for 4-12% of TCp, whereas <1.5% of EC was attributed to combustion of biomass. The carbonaceous aerosol source apportionment showed only minor variation between the four selected sites. However, Hyytiälä and Birkenes showed greater resemblance to each other, as did Lille Valby and Vavihill, the two latter being somewhat more influenced by anthropogenic sources. Ambient levels of organosulphates and nitrooxy-organosulphates in the Nordic rural background environment are reported for the first time in the present study. The most abundant organosulphate compounds were an

  13. Upper limits on the total cosmic-ray luminosity of individual sources

    SciTech Connect

    Anjos, R.C.; De Souza, V.; Supanitsky, A.D. E-mail: vitor@ifsc.usp.br

    2014-07-01

    In this paper, upper limits on the total luminosity of ultra-high-energy cosmic-rays (UHECR) E > 10{sup 18} eV) are determined for five individual sources. The upper limit on the integral flux of GeV--TeV gamma-rays is used to extract the upper limit on the total UHECR luminosity of individual sources. The correlation between upper limit on the integral GeV--TeV gamma-ray flux and upper limit on the UHECR luminosity is established through the cascading process that takes place during propagation of the cosmic rays in the background radiation fields, as explained in reference [1]. Twenty-eight sources measured by FERMI-LAT, VERITAS and MAGIC observatories have been studied. The measured upper limit on the GeV--TeV gamma-ray flux is restrictive enough to allow the calculation of an upper limit on the total UHECR cosmic-ray luminosity of five sources. The upper limit on the UHECR cosmic-ray luminosity of these sources is shown for several assumptions on the emission mechanism. For all studied sources an upper limit on the ultra-high-energy proton luminosity is also set.

  14. Atmospheric aerosol compositions and sources at two national background sites in northern and southern China

    NASA Astrophysics Data System (ADS)

    Zhu, Qiao; He, Ling-Yan; Huang, Xiao-Feng; Cao, Li-Ming; Gong, Zhao-Heng; Wang, Chuan; Zhuang, Xin; Hu, Min

    2016-08-01

    Although China's severe air pollution has become a focus in the field of atmospheric chemistry and the mechanisms of urban air pollution there have been researched extensively, few field sampling campaigns have been conducted at remote background sites in China, where air pollution characteristics on a larger scale are highlighted. In this study, an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS), together with an Aethalometer, was deployed at two of China's national background sites in northern (Lake Hongze site; 33.23° N, 118.33° E; altitude 21 m) and southern (Mount Wuzhi site; 18.84° N, 109.49° E; altitude 958 m) China in the spring seasons in 2011 and 2015, respectively, in order to characterize submicron aerosol composition and sources. The campaign-average PM1 concentration was 36.8 ± 19.8 µg m-3 at the northern China background (NCB) site, which was far higher than that at the southern China background (SCB) site (10.9 ± 7.8 µg m-3). Organic aerosol (OA) (27.2 %), nitrate (26.7 %), and sulfate (22.0 %) contributed the most to the PM1 mass at NCB, while OA (43.5 %) and sulfate (30.5 %) were the most abundant components of the PM1 mass at SCB, where nitrate only constituted a small fraction (4.7 %) and might have contained a significant amount of organic nitrates (5-11 %). The aerosol size distributions and organic aerosol elemental compositions all indicated very aged aerosol particles at both sites. The OA at SCB was more oxidized with a higher average oxygen to carbon (O / C) ratio (0.98) than that at NCB (0.67). Positive matrix factorization (PMF) analysis was used to classify OA into three components, including a hydrocarbon-like component (HOA, attributed to fossil fuel combustion) and two oxygenated components (OOA1 and OOA2, attributed to secondary organic aerosols from different source areas) at NCB. PMF analysis at SCB identified a semi-volatile oxygenated component (SV-OOA) and a low-volatility oxygenated

  15. A 220Rn source for the calibration of low-background experiments

    NASA Astrophysics Data System (ADS)

    Lang, R. F.; Brown, A.; Brown, E.; Cervantes, M.; Macmullin, S.; Masson, D.; Schreiner, J.; Simgen, H.

    2016-04-01

    We characterize two 40 kBq sources of electrodeposited 228Th for use in low-background experiments. The sources efficiently emanate 220Rn, a noble gas that can diffuse in a detector volume. 220Rn and its daughter isotopes produce α-, β-, and γ-radiation, which may used to calibrate a variety of detector responses and features, before decaying completely in only a few days. We perform various tests to place limits on the release of other long-lived isotopes. In particular, we find an emanation of < 0.008 atoms/min/kBq (90% CL) for 228Th and (1.53 ± 0.04) atoms/min/kBq for 224Ra. The sources lend themselves in particular to the calibration of detectors employing liquid noble elements such as argon and xenon. With the source mounted in a noble gas system, we demonstrate that filters are highly efficient in reducing the activity of these longer-lived isotopes further. We thus confirm the suitability of these sources even for use in next-generation experiments, such as XENON1T/XENONnT, LZ, and nEXO.

  16. Estimation of source contribution of PM2.5 at a background area in Korea

    NASA Astrophysics Data System (ADS)

    Han, S.; Kim, Y. P.; Lee, J.; Jung, C. H.; Lee, J.; Heo, J.; Kim, E. S.

    2016-12-01

    Organic aerosols account for a large fraction (20-80 wt%) in the ambient particulate matter, especially, in PM2.5 (particulate matter less than or equal to 2.5 μm in aerodynamic diameter). PM2.5 has detrimental effects on human health as well as the environmental effects such as climate change. Thus, identification of major sources of organic aerosols in PM2.5 at a background area is necessary to understand the characteristics of the ambient air in Korea. The objectives of this study are (1) estimation and identification of sources of organic aerosols (polycyclic aromatic hydrocarbons, n-alkanes, n-alkanoic acids, dicarboxylic acids, and sugars) using the Positive Matrix Factorization (PMF) model for the data measured from Jul. 2015 to Apr. 2016 at Anmyeon island, a back ground station in Korea, and (2) comparison with the PMF modeling result at Seoul to understand the characteristics of background areas of Korea. Five sources were identified at Anmyeon island. The profiles of some factors were similar to the profiles of Seoul and the factors at both sites showed similar seasonal variation in daily contribution.

  17. A new method to probe the thermal electron content of the Galaxy through spectral analysis of background sources

    NASA Astrophysics Data System (ADS)

    Jones, D. I.; Igoshev, A. P.; Haverkorn, M.

    2016-08-01

    We present a new method for probing the thermal electron content of the Galaxy by spectral analysis of background point sources in the absorption-only limit to the radiative transfer equation. In this limit, calculating the spectral index, α, of these sources using a natural logarithm results in an additive factor, which we denote {α _EM}, resulting from the absorption of radiation due to the Galactic thermal electron population. We find that this effect is important at very low frequencies (ν ≲ 200 MHz), and that the frequency spacing is critical. We model this effect by calculating the emission measure across the sky. A (smooth) thermal electron model for the Galaxy does not fit the observed emission measure distribution, but a simple, cloud-based model to represent the clumpy nature of the warm interstellar medium does. This model statistically reproduces the Galactic emission measure distribution as obtained independently from Hα data well. We find that at the lowest frequencies (˜10-50 MHz), the observed spectral index for a large segment of the Galaxy below Galactic latitudes of ≲15° could be changed significantly (i.e. {α _EM}≳ 0.1). This method therefore provides a correction to low-frequency spectral index measurements of extragalactic sources, and provides a sensitive probe of the thermal electron distribution of the Galaxy using current and next-generation low-frequency radio telescopes. We show that this effect should be robustly detectable individually in the strongest sources, and statistically in source samples at a level of {α _EM}≳ 0.18,0.06, and 0.02 for source densities of 10, 100, and 1000 sources per square degree.

  18. Correlations between 21-cm radiation and the cosmic microwave background from active sources

    NASA Astrophysics Data System (ADS)

    Berndsen, Aaron; Pogosian, Levon; Wyman, Mark

    2010-09-01

    Neutral hydrogen is ubiquitous, absorbing and emitting 21-cm radiation throughout much of the Universe's history. Active sources of perturbations, such as cosmic strings, would generate simultaneous perturbations in the distribution of neutral hydrogen and in the cosmic microwave background (CMB) radiation from recombination. Moving strings would create wakes leading to 21-cm brightness fluctuations, while also perturbing CMB light via the Gott-Kaiser-Stebbins effect. This would lead to spatial correlations between the 21-cm and CMB anisotropies. Passive sources, like inflationary perturbations, predict no cross-correlations prior to the onset of reionization. Thus, observation of any cross-correlation between CMB and 21-cm radiation from dark ages would constitute evidence for new physics. We calculate the cosmic string-induced correlations between CMB and 21-cm radiation and evaluate their observability.

  19. Quantifying primary and secondary source contributions to ultrafine particles in the UK urban background

    NASA Astrophysics Data System (ADS)

    Hama, S. M. L.; Cordell, R. L.; Monks, P. S.

    2017-10-01

    Total particle number (TNC, ≥7 nm diameter), particulate matter (PM2.5), equivalent black carbon (eBC) and gaseous pollutants (NO, NO2, NOx, O3, CO) have been measured at an urban background site in Leicester over two years (2014 and 2015). A derived chemical climatology for the pollutants showed maximum concentrations for all pollutants during the cold period except O3 which peaked during spring. Quantification of primary and secondary sources of ultrafine particles (UFPs) was undertaken using eBC as a tracer for the primary particle number concentration in the Leicester urban area. At the urban background site, which is influenced by fresh vehicle exhaust emissions, TNC was segregated into two components, TNC = N1 + N2. The component N1 represents components directly emitted as particles and compounds which nucleate immediately after emission. The component N2 represents the particles formed during the dilution and cooling of vehicle exhaust emissions and by in situ new particle formation (NPF). The values of highest N1 (49%) were recorded during the morning rush hours (07:00-09:00 h), correlating with NOx, while the maximum contribution of N2 to TNC was found at midday (11:00-14:00 h), at around 62%, correlated with O3. Generally, the percentage of N2 (57%) was greater than the percentage of N1 (43%) for all days at the AURN site over the period of the study. For the first time the impact of wind speed and direction on N1 and N2 was explored. The overall data analysis shows that there are two major sources contributing to TNC in Leicester: primary sources (traffic emissions) and secondary sources, with the majority of particles being of secondary origin.

  20. CONTRIBUTION OF UNRESOLVED POINT SOURCES TO THE DIFFUSE X-RAY BACKGROUND BELOW 1 keV

    SciTech Connect

    Gupta, A.; Galeazzi, M.

    2009-09-01

    We present here the analysis of X-ray point sources detected in several observations available in the XMM-Newton public archive. We focused, in particular, on energies below 1 keV, which are of particular relevance to the understanding of the diffuse X-ray background (DXB). The average field of all the exposures is 0.09 deg{sup -2}. We reached an average flux sensitivity of 5.8 x 10{sup -16}ergs{sup -1}cm{sup -2} in the soft band (0.5-2.0 keV) and 2.5 x 10{sup -16}ergs{sup -1}cm{sup -2} in the very soft band (0.4-0.6 keV). In this paper, we discuss the log N-log S results, the contribution to the integrated X-ray sky flux, and the properties of the cumulative spectrum from all sources. In particular, we found an excess flux at around 0.5 keV in the composite spectrum of faint sources. The excess seems to be a general property of all the fields observed suggesting an additional class of weak sources is contributing to the X-ray emission at these energies. Combining our results with previous investigations, we have also quantified the contribution of the individual components of the DXB in the 3/4 keV band.

  1. Local and regional sources of fine and coarse particulate matter based on traffic and background monitoring

    NASA Astrophysics Data System (ADS)

    Dimitriou, Konstantinos; Kassomenos, Pavlos

    2014-05-01

    The aim of this study was to identify local and exogenous sources affecting particulate matter (PM) levels in five major cities of Northern Europe namely: London, Paris, Hamburg, Copenhagen and Stockholm. Besides local emissions, PM profile at urban and suburban areas of the European Union (EU) is also influenced by regional PM sources due to atmospheric transport, thus geographical city distribution is of a great importance. At each city, PM10, PM2.5, NO2, SO2, CO and O3 air pollution data from two air pollution monitoring stations of the EU network were used. Different background characteristics of the selected two sampling sites at each city facilitated comparisons, providing a more exact analysis of PM sources. Four source apportionment methods: Pearson correlations among the levels of particulates and gaseous pollutants, characterisation of primal component analysis components, long-range transport analysis and extrapolation of PM size distribution ratios were applied. In general, fine (PM2.5) and coarse (PM10) particles were highly correlated, thus common sources are suggested. Combustion-originated gaseous pollutants (CO, NO2, SO2) were strongly associated to PM10 and PM2.5, primarily at areas severely affected by traffic. On the contrary, at background stations neighbouring important natural sources of particles or situated in suburban areas with rural background, natural emissions of aerosols were indicated. Series of daily PM2.5/PM10 ratios showed that minimum fraction values were detected during warm periods, due to higher volumes of airborne biogenic PM coarse, mainly at stations with important natural sources of particles in their vicinity. Hybrid single-particle Lagrangian integrated trajectory model was used, in order to extract 4-day backward air mass trajectories that arrived in the five cities which are under study during days with recorded PM10 exceedances. At all five cities, a significantly large fraction of those trajectories were classified

  2. Potential sources of background contaminants in solid phase extraction and microextraction.

    PubMed

    Stiles, Robert; Yang, Ill; Lippincott, Robert Lee; Murphy, Eileen; Buckley, Brian

    2007-05-01

    A study to identify the sources of background contamination from SPE, using a C-18 sorbent, and solid-phase microextraction (SPME), using a 70 microm carbowax/divinylbenzene (CW/DVB) fiber, was carried out. To determine the source of contamination, each material used in the procedure was isolated and examined for their contribution. The solid-phase column components examined were: sorbent material and frits, column housings and each solvent used to elute analytes off the column. The components examined in the SPME procedure were: SPME fiber, SPME vials, water (HPLC grade), and salt (sodium chloride) used to increase the ionic strength. The majority of the background contaminants from SPE were found to be from the SPE sorbent material and frits. The class of contaminants extracted during a blank extraction were phthalates and other plasticizers used during the manufacturing process. All had blank levels corresponding to measured concentrations below 2 ng/ mL, except for undecane, which had a concentration of 5.4 ng/mL. The most prevalent contaminants in the SPME blank procedure are 1,9-nonanediol, a mixture of phthalates and highly bis-substituted phenols. All the concentrations were below 2 ng/mL, with the exception of bis (2-ethylhexyl) phthalate, which had concentrations ranging from 5 to 20 ng/mL.

  3. The Individual and Family Self-Management Theory: background and perspectives on context, process, and outcomes.

    PubMed

    Ryan, Polly; Sawin, Kathleen J

    2009-01-01

    Current evidence indicates that individuals and families who engage in self-management (SM) behaviors improve their health outcomes. While the results of these studies are promising, there is little agreement as to the critical components of SM or directions for future study. This article offers an organized perspective of similar and divergent ideas related to SM. Unique contributions of prior work are highlighted and findings from studies are summarized. A new descriptive mid-range theory, Individual and Family Self-management Theory, is presented; assumptions are identified, concepts defined, and proposed relationships are outlined. This theory adds to the literature on SM by focusing on individuals, dyads within the family, or the family unit as a whole; explicating process components of SM; and proposing use of proximal and distal outcomes.

  4. The Individual and Family Self-management Theory: Background and Perspectives on Context, Process, and Outcomes

    PubMed Central

    Ryan, Polly; Sawin, Kathleen J.

    2009-01-01

    Current evidence indicates that individuals and families who engage in self-management (SM) behaviors improve their health outcomes. While the results of these studies are promising, there is little agreement as to the critical components of SM or directions for future study. This paper offers an organized perspective of similar and divergent ideas related to SM. Unique contributions of prior work are highlighted and findings from studies are summarized. A new descriptive mid-range theory, Individual and Family Self-management Theory, is presented; assumptions identified, concepts defined, and proposed relationships outlined. This theory adds to the literature on self-management by focusing on individual, dyads within the family, or the family unit as a whole; explicating process components of self-management; and proposing use of proximal and distal outcomes. PMID:19631064

  5. Background of Individual Education Plans (IEPs) Policy in Some Countries: A Review

    ERIC Educational Resources Information Center

    Alkahtani, Mohammed Ali; Kheirallah, Sahar Abdelfattah

    2016-01-01

    This paper seeks to provide a cogent outline of the current policies that six separate countries have on Individual Education Plans (IEPs), identifying the key features in each system. The chosen countries are Australia (Queen Island), Canada (British Columbia), New Zealand, the United Kingdom, the United States of America, and Saudi Arabia. The…

  6. Individualized Education Programs (IEPs) and Barriers for Parents from Culturally and Linguistically Diverse Backgrounds

    ERIC Educational Resources Information Center

    Jung, Adrian Woo

    2011-01-01

    In spite of theoretical validation and legal mandates in special education for parent participation, many studies have indicated that parents' roles in the Individualized Education Programs (IEP) process are still not noticeable and influential and that too often they are not being treated as an equal partner with school professionals. In…

  7. Factors, origin and sources affecting PM1 concentrations and composition at an urban background site

    NASA Astrophysics Data System (ADS)

    Squizzato, Stefania; Masiol, Mauro; Agostini, Chiara; Visin, Flavia; Formenton, Gianni; Harrison, Roy M.; Rampazzo, Giancarlo

    2016-11-01

    PM1 is widely believed to provide better information on the anthropogenic fraction of particulate matter pollution than PM2.5. However, data on PM1 are still limited in Europe as well as comprehensive information about its chemical composition and source apportionment and this gap is more evident in the pollution hot-spots still remaining in Europe, such as the Po Valley (Northern Italy). Elemental and organic carbon, 7 water soluble inorganic ions and 17 elements were quantified in 117 PM1 samples collected at an urban background site in Venice-Mestre, a large city located in the eastern Po Valley, during winter (December 2013-February 2014) and summer (May-July 2014) periods. Results show a strong seasonality for PM1 mass concentration (averages ranging from 6 ± 2 in summer to 34 ± 24 μg m- 3 in winter) and for most of the analysed species. Components mainly related to road traffic, residential heating, biomass burning and secondary inorganic aerosol (ammonium nitrate) reached their highest levels in winter, while mineral dust and marine components were elevated in summer. PMF analysis revealed 7 potential sources. Secondary inorganic aerosol (33%) and biomass burning (33%) are the major contributor in winter followed by EC-primary emissions (16%), aged sulphate (6%), road traffic (7%), fossil fuel combustion (%) and marine aerosol (3%). During summer, these sources account for 12%, 14%, 20%, 22%, 8%, 14% and 10%, respectively. Some PM1 sources are located near the sampling site (residential area, traffic road, industrial area) but a major contribution of long range transport is observed when high pollution events occur. The results give useful insights into PM1 composition in an urban area and chemical profiles of sources helpful in the interpretation of receptor model results.

  8. Source origin of trace elements in PM from regional background, urban and industrial sites of Spain

    NASA Astrophysics Data System (ADS)

    Querol, X.; Viana, M.; Alastuey, A.; Amato, F.; Moreno, T.; Castillo, S.; Pey, J.; de la Rosa, J.; Sánchez de la Campa, A.; Artíñano, B.; Salvador, P.; García Dos Santos, S.; Fernández-Patier, R.; Moreno-Grau, S.; Negral, L.; Minguillón, M. C.; Monfort, E.; Gil, J. I.; Inza, A.; Ortega, L. A.; Santamaría, J. M.; Zabalza, J.

    Despite their significant role in source apportionment analysis, studies dedicated to the identification of tracer elements of emission sources of atmospheric particulate matter based on air quality data are relatively scarce. The studies describing tracer elements of specific sources currently available in the literature mostly focus on emissions from traffic or large-scale combustion processes (e.g. power plants), but not on specific industrial processes. Furthermore, marker elements are not usually determined at receptor sites, but during emission. In our study, trace element concentrations in PM 10 and PM 2.5 were determined at 33 monitoring stations in Spain throughout the period 1995-2006. Industrial emissions from different forms of metallurgy (steel, stainless steel, copper, zinc), ceramic and petrochemical industries were evaluated. Results obtained at sites with no significant industrial development allowed us to define usual concentration ranges for a number of trace elements in rural and urban background environments. At industrial and traffic hotspots, average trace metal concentrations were highest, exceeding rural background levels by even one order of magnitude in the cases of Cr, Mn, Cu, Zn, As, Sn, W, V, Ni, Cs and Pb. Steel production emissions were linked to high levels of Cr, Mn, Ni, Zn, Mo, Cd, Se and Sn (and probably Pb). Copper metallurgy areas showed high levels of As, Bi, Ga and Cu. Zinc metallurgy was characterised by high levels of Zn and Cd. Glazed ceramic production areas were linked to high levels of Zn, As, Se, Zr, Cs, Tl, Li, Co and Pb. High levels of Ni and V (in association) were tracers of petrochemical plants and/or fuel-oil combustion. At one site under the influence of heavy vessel traffic these elements could be considered tracers (although not exclusively) of shipping emissions. Levels of Zn-Ba and Cu-Sb were relatively high in urban areas when compared with industrialised regions due to tyre and brake abrasion, respectively.

  9. THE ABUNDANCE OF X-SHAPED RADIO SOURCES: IMPLICATIONS FOR THE GRAVITATIONAL WAVE BACKGROUND

    SciTech Connect

    Roberts, David H.; Saripalli, Lakshmi; Subrahmanyan, Ravi

    2015-09-01

    Coalescence of supermassive black holes (SMBHs) in galaxy mergers is potentially the dominant contributor to the low frequency gravitational wave background (GWB). It was proposed by Merritt and Ekers that X-shaped radio galaxies are signposts of such coalescences and that their abundance might be used to predict the magnitude of the GWB. In Roberts et al. we presented radio images of all 52 X-shaped radio source candidates out of the sample of 100 selected by Cheung for which archival VLA data were available. These images indicate that at most 21% of the candidates might be genuine X-shaped radio sources that were formed by a restarting of beams in a new direction following a major merger. This suggests that fewer than 1.3% of extended radio sources appear to be candidates for genuine axis reorientations (“spin flips”), much smaller than the 7% suggested by Leahy and Parma. Thus, the associated GWB may be substantially smaller than previous estimates. These results can be used to normalize detailed calculations of the SMBH coalescence rate and the GWB.

  10. MID-INFRARED PHOTOMETRIC ANALYSIS OF MAIN BELT ASTEROIDS: A TECHNIQUE FOR COLOR-COLOR DIFFERENTIATION FROM BACKGROUND ASTROPHYSICAL SOURCES

    SciTech Connect

    Bhattacharya, B.; Helou, G.; Noriega-Crespo, A.; Surace, J.; Capak, P.; Grillmair, C.; Rebull, L. M.; Penprase, B. E.; Meadows, V. S.; Salvato, M.; Aussel, H.; Ilbert, O.; Le Floc'h, E.; Looper, D.; Granvik, M.; Sanders, D. B.; Giorgini, J. D.; Hagen, A.; Reach, W. T.

    2010-09-01

    The Spitzer Space Telescope routinely detects asteroids in astrophysical observations near the ecliptic plane. For the galactic or extragalactic astronomer, these solar system bodies can introduce appreciable uncertainty into the source identification process. We discuss an infrared color discrimination tool that may be used to distinguish between solar system objects and extrasolar sources. We employ four Spitzer Legacy data sets, the First Look Survey-Ecliptic Plane Component (FLS-EPC), SCOSMOS, SWIRE, and GOODS. We use the Standard Thermal Model to derive FLS-EPC main belt asteroid (MBA) diameters of 1-4 km for the numbered asteroids in our sample and note that several of our solar system sources may have fainter absolute magnitude values than previously thought. A number of the MBAs are detected at flux densities as low as a few tens of {mu}Jy at 3.6 {mu}m. As the FLS-EPC provides the only 3.6-24.0 {mu}m observations of individual asteroids to date, we are able to use this data set to carry out a detailed study of asteroid color in comparison to astrophysical sources observed by SCOSMOS, SWIRE, and GOODS. Both SCOSMOS and SWIRE have identified a significant number of asteroids in their data, and we investigate the effectiveness of using relative color to distinguish between asteroids and background objects. We find a notable difference in color in the IRAC 3.6-8.0 mm and MIPS 24 {mu}m bands between the majority of MBAs, stars, galaxies, and active galactic nuclei, though this variation is less significant when comparing fluxes in individual bands. We find median colors for the FLS-EPC asteroids to be [F(5.8/3.6), F(8.0/4.5), F(24/8)] = (4.9 {+-} 1.8, 8.9 {+-} 7.4, 6.4 {+-} 2.3). Finally, we consider the utility of this technique for other mid-infrared observations that are sensitive to near-Earth objects, MBAs, and trans-Neptunian objects. We consider the potential of using color to differentiate between solar system and background sources for several space

  11. Reconstructing Emission from Pre-reionization Sources with Cosmic Infrared Background Fluctuation Measurements by the JWST

    NASA Astrophysics Data System (ADS)

    Kashlinsky, A.; Mather, J. C.; Helgason, K.; Arendt, R. G.; Bromm, V.; Moseley, S. H.

    2015-05-01

    We present new methodology to use cosmic infrared background (CIB) fluctuations to probe sources at 10≲ z≲ 30 from a James Webb Space Telescope (JWST)/NIRCam configuration that will isolate known galaxies to 28 AB mag at 0.5-5 μm. At present significant mutually consistent source-subtracted CIB fluctuations have been identified in the Spitzer and AKARI data at ˜2-5 μm, but we demonstrate internal inconsistencies at shorter wavelengths in the recent CIBER data. We evaluate CIB contributions from remaining galaxies and show that the bulk of the high-z sources will be in the confusion noise of the NIRCam beam, requiring CIB studies. The accurate measurement of the angular spectrum of the fluctuations and probing the dependence of its clustering component on the remaining shot noise power would discriminate between the various currently proposed models for their origin and probe the flux distribution of its sources. We show that the contribution to CIB fluctuations from remaining galaxies is large at visible wavelengths for the current instruments precluding probing the putative Lyman-break of the CIB fluctuations. We demonstrate that with the proposed JWST configuration such measurements will enable probing the Lyman-break. We develop a Lyman-break tomography method to use the NIRCam wavelength coverage to identify or constrain, via the adjacent two-band subtraction, the history of emissions over 10≲ z≲ 30 as the universe comes out of the “Dark Ages.” We apply the proposed tomography to the current Spitzer/IRAC measurements at 3.6 and 4.5 μm, to find that it already leads to interestingly low upper limit on emissions at z≳ 30.

  12. Faint Radio Source Constraints on the Origin of the Hard X-ray Background

    NASA Astrophysics Data System (ADS)

    Moran, E. C.; Helfand, D. J.

    1999-04-01

    ASCA and BeppoSAX have greatly expanded our understanding of the hard X-ray properties of nearby starburst and Seyfert galaxies, allowing, for the first time, detailed estimates of their respective contributions to the hard X-ray background (XRB) to be made. Unfortunately, the sensitivities of these instruments are insufficient to probe either population directly at intermediate and high redshifts, where the majority of the XRB originates. As a result, discrete-source XRB models must typically rely on highly uncertain assumptions about the evolution of potential contributors with cosmic time. Clearly, it would be helpful to identify an observational constraint that minimizes (or eliminates) the need for these assumptions. Since X-ray galaxies of all types produce radio emission in conjunction with their particular brand of activity, we propose that the faint radio source population may provide such a constraint. Existing deep radio surveys, which extend to the microjansky level, should contain both starburst and Seyfert galaxies at cosmological distances. However, optical identification programs carried out to date have revealed that the majority of sub-mJy radio sources are associated with star-forming galaxies rather than AGNs, suggesting that the starburst contribution to the XRB could be significant. By combining hard X-ray and radio data for nearby starburst galaxies with the measured log N--log S relation for sub-mJy radio sources, we estimate that starburst galaxies may produce as much as 15--45% of the 5 keV XRB. Preliminary results of a similar analysis for Seyfert galaxies are complimentary, indicating that these objects cannot be responsible for all of the hard XRB.

  13. Reconstructing Emission from Pre-Reionization Sources with Cosmic Infrared Background Fluctuation Measurements by the JWST

    NASA Technical Reports Server (NTRS)

    Kashlinsky, A.; Mather, J. C.; Helgason, K.; Arendt, R. G.; Bromm, V.; Moseley, S. H.

    2015-01-01

    We present new methodology to use cosmic infrared background (CIB) fluctuations to probe sources at 10 less than or approx. equal to z less than or approx. equal to 30 from a James Webb Space Telescope (JWST) NIRCam configuration that will isolate known galaxies to 28 AB mag at 0.55 m. At present significant mutually consistent source-subtracted CIB fluctuations have been identified in the Spitzer and AKARI data at 25 m, but we demonstrate internal inconsistencies at shorter wavelengths in the recent CIBER data. We evaluate CIB contributions from remaining galaxies and show that the bulk of the high-z sources will be in the confusion noise of the NIRCam beam, requiring CIB studies. The accurate measurement of the angular spectrum of the fluctuations and probing the dependence of its clustering component on the remaining shot noise power would discriminate between the various currently proposed models for their origin and probe the flux distribution of its sources. We show that the contribution to CIB fluctuations from remaining galaxies is large at visible wavelengths for the current instruments precluding probing the putative Lyman-break of the CIB fluctuations. We demonstrate that with the proposed JWST configuration such measurements will enable probing the Lyman-break. We develop a Lyman-break tomography method to use the NIRCam wavelength coverage to identify or constrain, via the adjacent two-band subtraction, the history of emissions over 10 less than or approx. equal to z less than or approx. equal to 30 as the universe comes out of the Dark Ages. We apply the proposed tomography to the current SpitzerIRAC measurements at 3.6 and 4.5 m, to find that it already leads to interestingly low upper limit on emissions at z greater than or approx. equal to 30.

  14. Local Group dSph radio survey with ATCA (I): observations and background sources

    NASA Astrophysics Data System (ADS)

    Regis, Marco; Richter, Laura; Colafrancesco, Sergio; Massardi, Marcella; de Blok, W. J. G.; Profumo, Stefano; Orford, Nicola

    2015-04-01

    Dwarf spheroidal (dSph) galaxies are key objects in near-field cosmology, especially in connection to the study of galaxy formation and evolution at small scales. In addition, dSphs are optimal targets to investigate the nature of dark matter. However, while we begin to have deep optical photometric observations of the stellar population in these objects, little is known so far about their diffuse emission at any observing frequency, and hence on thermal and non-thermal plasma possibly residing within dSphs. In this paper, we present deep radio observations of six local dSphs performed with the Australia Telescope Compact Array (ATCA) at 16 cm wavelength. We mosaicked a region of radius of about 1 deg around three `classical' dSphs, Carina, Fornax, and Sculptor, and of about half of degree around three `ultrafaint' dSphs, BootesII, Segue2, and Hercules. The rms noise level is below 0.05 mJy for all the maps. The restoring beams full width at half-maximum ranged from 4.2 arcsec × 2.5 arcsec to 30.0 arcsec × 2.1 arcsec in the most elongated case. A catalogue including the 1392 sources detected in the six dSph fields is reported. The main properties of the background sources are discussed, with positions and fluxes of brightest objects compared with the FIRST, NVSS, and SUMSS observations of the same fields. The observed population of radio emitters in these fields is dominated by synchrotron sources. We compute the associated source number counts at 2 GHz down to fluxes of 0.25 mJy, which prove to be in agreement with AGN count models.

  15. Microsatellites: Evolutionary and methodological background and empirical applications at individual, population, and phylogenetic levels

    USGS Publications Warehouse

    Scribner, Kim T.; Pearce, John M.; Baker, Allan J.

    2000-01-01

    The recent proliferation and greater accessibility of molecular genetic markers has led to a growing appreciation of the ecological and evolutionary inferences that can be drawn from molecular characterizations of individuals and populations (Burke et al. 1992, Avise 1994). Different techniques have the ability to target DNA sequences which have different patterns of inheritance, different modes and rates of evolution and, concomitantly, different levels of variation. In the quest for 'the right marker for the right job', microsatellites have been widely embraced as the marker of choice for many empirical genetic studies. The proliferation of microsatellite loci for various species and the voluminous literature compiled in very few years associated with their evolution and use in various research applications, exemplifies their growing importance as a research tool in the biological sciences.The ability to define allelic states based on variation at the nucleotide level has afforded unparalleled opportunities to document the actual mutational process and rates of evolution at individual microsatellite loci. The scrutiny to which these loci have been subjected has resulted in data that raise issues pertaining to assumptions formerly stated, but largely untestable for other marker classes. Indeed this is an active arena for theoretical and empirical work. Given the extensive and ever-increasing literature on various statistical methodologies and cautionary notes regarding the uses of microsatellites, some consideration should be given to the unique characteristics of these loci when determining how and under what conditions they can be employed.

  16. Decision-making in the critically ill neonate: cultural background v individual life experiences.

    PubMed Central

    Hammerman, C; Kornbluth, E; Lavie, O; Zadka, P; Aboulafia, Y; Eidelman, A I

    1997-01-01

    OBJECTIVES: In treating critically ill neonates, situations occasionally arise in which aggressive medical treatment prolongs the inevitable death rather than prolonging life. Decisions as to limitation of neonatal medical intervention remain controversial and the primary responsibility of the generally unprepared family. This research was designed to study response patterns of expectant mothers towards treatment of critically ill and/or malformed infants. DESIGN/SETTING: Attitudes were studied via comprehensive questionnaires divided into three sections: 1-Sociodemographic data and prior personal experience with perinatal problems; 2-Theoretical philosophical principles used in making medical ethical decisions; and 3-Hypothetical case scenarios with choices of treatment options. SUBJECTS AND RESULTS: Six hundred and fifty pregnant women were studied. Maternal birthplace (p = 0.005) and level of religious observance (p = 0.02) were strongly associated with the desire for maximally aggressive medical intervention in the hypothetical case scenario. Specific personal experiences such as infertility problems, previous children with serious mental or physical problems were not correlated with the selection of different treatment choices. Of the theoretical principles studied, only the desire to preserve life at all costs was significantly associated with the choice for maximal medical treatment (p = 0.003). CONCLUSIONS: Maternal ethnocultural background and philosophical principles more profoundly influenced medical ethical decision-making than did specific personal life experiences. PMID:9220330

  17. Prequantum classical statistical field theory: background field as a source of everything?

    NASA Astrophysics Data System (ADS)

    Khrennikov, Andrei

    2011-07-01

    Prequantum classical statistical field theory (PCSFT) is a new attempt to consider quantum mechanics (QM) as an emergent phenomenon, cf. with De Broglie's "double solution" approach, Bohmian mechanics, stochastic electrodynamics (SED), Nelson's stochastic QM and its generalization by Davidson, 't Hooft's models and their development by Elze. PCSFT is a comeback to a purely wave viewpoint on QM, cf. with early Schrodinger. There is no quantum particles at all, only waves. In particular, photons are simply wave-pulses of the classical electromagnetic field, cf. SED. Moreover, even massive particles are special "prequantum fields": the electron field, the neutron field, and so on. PCSFT claims that (sooner or later) people will be able to measure components of these fields: components of the "photonic field" (the classical electromagnetic field of low intensity), electronic field, neutronic field, and so on. At the moment we are able to produce quantum correlations as correlations of classical Gaussian random fields. In this paper we are interested in mathematical and physical reasons of usage of Gaussian fields. We consider prequantum signals (corresponding to quantum systems) as composed of a huge number of wave-pulses (on very fine prequantum time scale). We speculate that the prequantum background field (the field of "vacuum fluctuations") might play the role of a source of such pulses, i.e., the source of everything.

  18. Genetic and environmental sources of individual religiousness: the roles of individual personality traits and perceived environmental religiousness.

    PubMed

    Kandler, Christian; Riemann, Rainer

    2013-07-01

    In the current study, we examined the genetic and environmental sources of the links between individual religiousness and individual personality traits, perceived parental religiousness, and perceived peer religiousness. Data from 870 individuals (incl. 394 twin pairs) were analyzed. Variance in individual religiousness was significantly influenced by genetic effects, environmental influences shared by twins reared together, and individual-specific environmental influences. Individual religiousness showed significant associations with age, sex, specific personality traits (e.g., agreeableness, openness to values), and perceived religiousness of important social interaction partners, such as parents, best friends, and spouses. The links to personality traits were relatively small and primarily genetically mediated. The associations between individual religiousness and parental religiousness were substantial and mediated by shared environmental effects. These links significantly decreased across age accompanying a significant decrease of shared environmental influences on individual religiousness. The correlations between individual religiousness and perceived religiousness of spouses and best friends were relatively moderate but increased with age. These associations were mediated by genetic as well as nonshared environmental sources accompanying an increase of nonshared environmental influences on individual religiousness with age. The results suggest that inter-individual differences in religiousness are due to multiple sources.

  19. Effects of individual sound sources on the subjective loudness and acoustic comfort in underground shopping streets.

    PubMed

    Kang, Jian; Meng, Qi; Jin, Hong

    2012-10-01

    Previous studies have demonstrated that human evaluation of subjective loudness and acoustic comfort depends on a series of factors in a particular situation rather than only on sound pressure levels. In the present study, a large-scale subjective survey has been undertaken on underground shopping streets in Harbin, China, to determine how individual sound sources influence subjective loudness and acoustic comfort evaluation. Based on the analysis of case study results, it has been shown that all individual sound sources can increase subjective loudness to a certain degree. However, their levels of influence on acoustic comfort are different. Background music and the public address system can increase acoustic comfort, with a mean difference of 0.18 to 0.32 and 0.21 to 0.27, respectively, where a five-point bipolar category scale is used. Music from shops and vendor shouts can decrease acoustic comfort, with a mean difference of -0.11 to -0.38 and -0.39 to -0.62, respectively. The feasibility of improving acoustic comfort by changing certain sound sources is thus demonstrated.

  20. Evaluation of aerosol sources at European high altitude background sites with trajectory statistical methods

    NASA Astrophysics Data System (ADS)

    Salvador, P.; Artíñano, B.; Pio, C. A.; Afonso, J.; Puxbaum, H.; Legrand, M.; Hammer, S.; Kaiser, A.

    2009-04-01

    During the last years, the analysis of a great number of back-trajectories from receptor sites has turned out to be a valuable tool to identify sources and sinks areas of atmospheric particulate matter (PM) or to reconstruct their average spatial distribution. A number of works have applied different trajectory statistical methods (TSM), which allow working simultaneously with back-trajectories computed from one or several receptor points and PM concentration values registered there. In spite of these methods have many limitations, they are simple and effective methods to detect the relevant source regions and the air flow regimes which are connected with regional and large-scale air pollution transport. In this study 5-day backward air trajectories arriving over 3 monitoring sites, were utilised and analysed simultaneously with the PM levels and chemical composition values registered there. These sites are located in the centre of Europe and can be classified into natural continental background (Schauinsland-SIL in Germany (1205 m asl), Puy de Dôme-PDD in France (1450 m asl) and Sonnblick-SBO in Austria (3106 m asl)). In the framework of the CARBOSOL European project, weekly aerosol samples were collected with High Volume Samplers (DIGITEL DH77) and PM10 (SIL and PDD) or PM2.5 (SBO) inlets, on quartz fibre filters. Filter samples were treated and analyzed for determining the levels of major organic fractions (OC, EC) and inorganic ions. Additionally, analyses for specific organic compounds were also carried out whenever was possible (Pio et al., 2007). For each day of the sampling period, four trajectories ending at 00:00, 06:00, 12:00 and 18:00 h UTC have been computed by the Norwegian Institute for Air Research NILU (SIL and PDD) and the Central Institute for Meteorology and Geophysics of Austria (SBO) using the FLEXTRA model (Stohl et al., 1995). In all, more than 8000 complete trajectories were available for analysis, each with 40 endpoints. Firstly air mass

  1. Radiative Transfer in a Translucent Cloud Illuminated by an Extended Background Source

    NASA Astrophysics Data System (ADS)

    Biganzoli, Davide; Potenza, Marco A. C.; Robberto, Massimo

    2017-05-01

    We discuss the radiative transfer theory for translucent clouds illuminated by an extended background source. First, we derive a rigorous solution based on the assumption that multiple scatterings produce an isotropic flux. Then we derive a more manageable analytic approximation showing that it nicely matches the results of the rigorous approach. To validate our model, we compare our predictions with accurate laboratory measurements for various types of well-characterized grains, including purely dielectric and strongly absorbing materials representative of astronomical icy and metallic grains, respectively, finding excellent agreement without the need to add free parameters. We use our model to explore the behavior of an astrophysical cloud illuminated by a diffuse source with dust grains having parameters typical of the classic ISM grains of Draine & Lee and protoplanetary disks, with an application to the dark silhouette disk 114-426 in Orion Nebula. We find that the scattering term modifies the transmitted radiation, both in terms of intensity (extinction) and shape (reddening) of the spectral distribution. In particular, for small optical thickness, our results show that scattering makes reddening almost negligible at visible wavelengths. Once the optical thickness increases enough and the probability of scattering events becomes close to or larger than 1, reddening becomes present but is appreciably modified with respect to the standard expression for line-of-sight absorption. Moreover, variations of the grain refractive index, in particular the amount of absorption, also play an important role in changing the shape of the spectral transmission curve, with dielectric grains showing the minimum amount of reddening.

  2. Faraday rotation from magnesium II absorbers toward polarized background radio sources

    SciTech Connect

    Farnes, J. S.; O'Sullivan, S. P.; Corrigan, M. E.; Gaensler, B. M.

    2014-11-01

    Strong singly ionized magnesium (Mg II) absorption lines in quasar spectra typically serve as a proxy for intervening galaxies along the line of sight. Previous studies have found a correlation between the number of these Mg II absorbers and the Faraday rotation measure (RM) at ≈5 GHz. We cross-match a sample of 35,752 optically identified non-intrinsic Mg II absorption systems with 25,649 polarized background radio sources for which we have measurements of both the spectral index and RM at 1.4 GHz. We use the spectral index to split the resulting sample of 599 sources into flat-spectrum and steep-spectrum subsamples. We find that our flat-spectrum sample shows significant (∼3.5σ) evidence for a correlation between Mg II absorption and RM at 1.4 GHz, while our steep-spectrum sample shows no such correlation. We argue that such an effect cannot be explained by either luminosity or other observational effects, by evolution in another confounding variable, by wavelength-dependent polarization structure in an active galactic nucleus, by the Galactic foreground, by cosmological expansion, or by partial coverage models. We conclude that our data are most consistent with intervenors directly contributing to the Faraday rotation along the line of sight, and that the intervening systems must therefore have coherent magnetic fields of substantial strength ( B-bar =1.8±0.4 μG). Nevertheless, the weak nature of the correlation will require future high-resolution and broadband radio observations in order to place it on a much firmer statistical footing.

  3. Aspects of petrochemical pollution in southeastern Louisiana (USA): pre-Katrina background and source characterization.

    PubMed

    Iqbal, Javed; Gisclair, David; McMillin, Debra J; Portier, Ralph J

    2007-09-01

    Background petroleum pollution before Hurricane Katrina in southeastern Louisiana (USA) coastal sediments was evaluated at 320 locations in three consecutive years for polycyclic aromatic hydrocarbons (PAHs), saturated alkanes (nC9-nC35), and petroleum biomarker compounds (hopanes, steranes, pristane, and phytane). Approximately 90% of the sample locations had a total PAH concentration of less than 2.0 microg/g and total saturated alkane concentration of less than 17 microg/g, with 50% indicating a total PAH concentration of less than 200 ng/g. Upper limit or baseline high concentration for total PAHs was 1.5 microg/g, comparable to the 2.18 microg/g reported for the National Status and Trends (NST) Program of the National Oceanic and Atmospheric Administration (NOAA). Thus, 85% of sites were below the baseline high concentration. Baseline high total PAHs at 6% of the sites (described as land) was 5.1 microg/g, comparable to the 4 microg/g benchmark calculated for NST. The three-year average total PAH concentration for 95% of the sites was less than 7.5 microg/g, a defined limit of fivefold the baseline high concentration. Samples indicated petrogenic, pyrogenic, and natural/biogenic hydrocarbon inputs. Contaminant levels exceeded the state soil screening limits at only 3% of the 320 locations. Federal screening limits proposed by the NOAA for ecological effects were exceeded at only 18% of the sites (including those sites exceeding the state limit). Only 4% of the sites had concentrations exceeding the NOAA effect range-low (ER-L) in more than one collection year. At least 61% of the analytes exceeding the ER-L were pyrogenic source indicators. Source-fingerprint analysis of these selected samples showed 10 samples with notable petroleum contamination, whereas six indicated pyrogenic input. Of all samples collected, only one site showed relatively fresh/lightly weathered petroleum.

  4. Assessment of sources of error in Background Oriented Schlieren (BOS) measurements

    NASA Astrophysics Data System (ADS)

    Rajendran, Lalit; Singh, Bhavini; Giarra, Matthew; Bane, Sally; Vlachos, Pavlos

    2016-11-01

    Background Oriented Schlieren (BOS) is used to measure density gradients in a flow by tracking the apparent distortion of a target dot pattern. The quality of a BOS measurement depends on several factors such as the dot pattern, illumination, density gradients, optical system, cross-correlation algorithms and density reconstruction. To understand their contributions to the final error in the measurement and to develop an optimal set of design rules, we generate high fidelity synthetic images using ray tracing simulations. Past studies use ad-hoc models (or none) for simulating these effects and do not represent the issues introduced in a typical BOS setup, thereby limiting their utility. We have developed and implemented an image generation methodology based on ray tracing, where light rays emitted from a dot pattern are traced through the experimental setup including the density gradients, to generate high fidelity images representative of a real experiment. We apply this methodology to perform a comprehensive analysis of the various sources of error in the BOS technique and to better understand the issues involved in designing a successful experiment. The results of this study can guide future experiments and provide directions to improve the image analysis tools.

  5. Sources of Individual Differences in Spatial Visualization Ability.

    ERIC Educational Resources Information Center

    Salthouse, Timothy A.; And Others

    1990-01-01

    Three hypotheses accounting for individual differences in spatial visualization ability were investigated in 2 experiments with 142 male undergraduates at Georgia Institute of Technology (Atlanta). Support was found for the preservation-under-transformation hypothesis, suggesting that effectiveness of storage during concurrent information…

  6. Sources of Individual Differences in Children's Understanding of Fractions

    ERIC Educational Resources Information Center

    Vukovic, Rose K.; Fuchs, Lynn S.; Geary, David C.; Jordan, Nancy C.; Gersten, Russell; Siegler, Robert S.

    2014-01-01

    Longitudinal associations of domain-general and numerical competencies with individual differences in children's understanding of fractions were investigated. Children (n = 163) were assessed at 6 years of age on domain-general (nonverbal reasoning, language, attentive behavior, executive control, visual-spatial memory) and numerical (number…

  7. Sources of Individual Differences in Children's Understanding of Fractions

    ERIC Educational Resources Information Center

    Vukovic, Rose K.; Fuchs, Lynn S.; Geary, David C.; Jordan, Nancy C.; Gersten, Russell; Siegler, Robert S.

    2014-01-01

    Longitudinal associations of domain-general and numerical competencies with individual differences in children's understanding of fractions were investigated. Children (n = 163) were assessed at 6 years of age on domain-general (nonverbal reasoning, language, attentive behavior, executive control, visual-spatial memory) and numerical (number…

  8. Lifetime prevalence of mental disorders among first and second generation individuals with Turkish migration backgrounds in Germany.

    PubMed

    Dingoyan, Demet; Schulz, Holger; Kluge, Ulrike; Penka, Simone; Vardar, Azra; von Wolff, Alessa; Strehle, Jens; Wittchen, Hans-Ulrich; Koch, Uwe; Heinz, Andreas; Mösko, Mike

    2017-05-11

    This paper focuses on the lifetime prevalence of mental disorders in individuals with Turkish migration backgrounds in Germany, as there is a lack of reliable epidemiological data on this subject. In total, 662 adults with Turkish migration backgrounds were interviewed in Hamburg and Berlin by trained, bilingual interviewers using the computerized Composite International Diagnostic Interview (CIDI DIA-X Version 2.8) to assess diagnoses according to the DSM-IVTR. The analyses showed a weighted lifetime prevalence of 78.8% for any mental disorder, 21.6% for more than one and 7.3% for five or more disorders. Any mood disorder (41.9%), any anxiety disorder (35.7%) and any somatoform disorder/syndrome (33.7%) had the highest prevalences. Despite the sociodemographic differences between the first and second generations, there were no significant differences in the lifetime prevalence between generations, with the exception of any bipolar disorder. Female gender, older age and no current partnership were significantly associated with the occurrence of any mood disorder. Overall, the results indicate a high lifetime prevalence in individuals with Turkish migration backgrounds in Germany. These initial data are highly relevant to the German clinical and psychosocial healthcare system; however, the methodological limitations and potential biases should be considered when interpreting the results.

  9. Dimensions of Diversity and Perception of Having Learned From Individuals From Different Backgrounds: The Particular Importance of Racial Diversity.

    PubMed

    Morrison, Emory; Grbic, Douglas

    2015-07-01

    Selective higher education institutions that take race into account in admissions decisions must be able to demonstrate that their policy is justified by a compelling governmental interest, is narrowly tailored, and is the least restrictive means for achieving that interest. The authors thus investigate whether, among medical students, the association between racial diversity (as distinct from other forms of diversity) and learning from individuals from different backgrounds is unique. The authors examined six dimensions of diversity, including racial/ethnic diversity, among the 2010, 2011, and 2012 cohorts of fourth-year medical students in the United States. They also examined students' responses to two Medical Student Graduation Questionnaire items pertaining to learning from individuals from different backgrounds. They modeled the association between each of the school-level dimensions of diversity and the student-level responses to having learned from others with different backgrounds, and they assessed whether associations vary across different groups of students. Racial/ethnic diversity is unique in its very strong association with student perceptions of having learned from others who are different. The association between racial/ethnic diversity and student perceptions of having learned from others who are different is especially strong for members of historically underrepresented minority groups. Compared with other forms of diversity, racial/ethnic diversity has a unique association with students' perceptions of learning from others who are different. This association is of particular relevance to admissions and diversity policies in an era of strict scrutiny of these policies.

  10. Line-source simulation for shallow-seismic data. Part 1: theoretical background

    NASA Astrophysics Data System (ADS)

    Forbriger, Thomas; Groos, Lisa; Schäfer, Martin

    2014-09-01

    Equivalent line-source seismograms can be obtained from shallow seismic field recordings by (1) convolving the waveforms with √{t^{-1}}, (2) applying a √{t^{-1}} time-domain taper, where t is traveltime and (3) scaling the waveform with r_{offset}√{2}, where roffset is source-to-receiver offset. We require such a procedure when applying algorithms of 2-D adjoint full-waveform inversion (FWI) to shallow-seismic data. Although derived from solutions for acoustic waves in homogeneous full space this simple procedure performs surprisingly well when applied to vertical and radial components of shallow-seismic recordings from hammer blows or explosions. This is the case even in the near field of the force, although the procedure is derived from a far-field approximation. Similar approximative procedures recommended in literature are optimized for reflected waves and do not convert the amplitudes of all shallow seismic wavefield constituents equally well. We demonstrate the suitability of the proposed method for the viscoelastic case by numerical examples as well as analytical considerations. In contrast to the proposed single-trace procedure, integral-transform approaches are exact for all viscoelastic wavefield constituents of the near- and far-field in unknown 1-D-heterogeneous structure. Unfortunately, integral-transform approaches suffer from artefacts in applications to data sampled on 2-D structures. Here, we use the Fourier-Bessel integral transformation as a reference in 1-D heterogeneous structures. We unroll the wave-theoretical background of both approaches in order to demonstrate, why the simplistic single-trace simulation approach derived from the asymptotic acoustic case can perform so well when applied to the shallow elastic wavefield. Further we give recommendations for practical implementation and application to field data of the proposed simulation method and compare to the results of alternative conversion rules. The performance of the conversion

  11. Sources contributing to background surface ozone in the US Intermountain West

    NASA Astrophysics Data System (ADS)

    Zhang, L.; Jacob, D. J.; Yue, X.; Downey, N. V.; Wood, D. A.; Blewitt, D.

    2014-06-01

    We quantify the sources contributing to background surface ozone concentrations in the US Intermountain West by using the GEOS-Chem chemical transport model with 1 / 2° × 2 / 3° horizontal resolution to interpret the Clean Air Status and Trends Network (CASTNet) ozone monitoring data for 2006-2008. We isolate contributions from lightning, wildfires, the stratosphere, and California pollution. Lightning emissions are constrained by observations and wildfire emissions are estimated from daily fire reports. We find that lightning increases mean surface ozone in summer by 10 ppbv in the Intermountain West, with moderate variability. Wildfire plumes generate high-ozone events in excess of 80 ppbv in GEOS-Chem, but CASTNet ozone observations in the Intermountain West show no enhancements during these events nor do they show evidence of regional fire influence. Models may overestimate ozone production in fresh fire plumes because of inadequate chemistry and grid-scale resolution. The highest ozone concentrations observed in the Intermountain West (> 75 ppbv) in spring are associated with stratospheric intrusions. The model captures the timing of these intrusions but not their magnitude, reflecting numerical diffusion intrinsic to Eulerian models. This can be corrected statistically through a relationship between model bias and the model-diagnosed magnitude of stratospheric influence; with this correction, models may still be useful to forecast and interpret high-ozone events from stratospheric intrusions. We show that discrepancy between models in diagnosing stratospheric influence is due in part to differences in definition, i.e., whether stratospheric ozone is diagnosed as produced in the stratosphere (GEOS-Chem definition) or as transported from above the tropopause. The latter definition can double the diagnosed stratospheric influence in surface air by labeling as "stratospheric" any ozone produced in the troposphere and temporarily transported to the stratosphere

  12. Sources of individual differences in children's understanding of fractions.

    PubMed

    Vukovic, Rose K; Fuchs, Lynn S; Geary, David C; Jordan, Nancy C; Gersten, Russell; Siegler, Robert S

    2014-01-01

    Longitudinal associations of domain-general and numerical competencies with individual differences in children's understanding of fractions were investigated. Children (n = 163) were assessed at 6 years of age on domain-general (nonverbal reasoning, language, attentive behavior, executive control, visual-spatial memory) and numerical (number knowledge) competencies; at 7 years on whole-number arithmetic computations and number line estimation; and at 10 years on fraction concepts. Mediation analyses controlling for general mathematics ability and general academic ability revealed that numerical and mathematical competencies were direct predictors of fraction concepts, whereas domain-general competencies supported the acquisition of fraction concepts via whole-number arithmetic computations or number line estimation. Results indicate multiple pathways to fraction competence.

  13. Cultural regulation of emotion: individual, relational, and structural sources

    PubMed Central

    De Leersnyder, Jozefien; Boiger, Michael; Mesquita, Batja

    2013-01-01

    The most prevalent and intense emotional experiences differ across cultures. These differences in emotional experience can be understood as the outcomes of emotion regulation, because emotions that fit the valued relationships within a culture tend to be most common and intense. We review evidence suggesting that emotion regulation underlying cultural differences in emotional experience often takes place at the point of emotion elicitation through the promotion of situations and appraisals that are consistent with culturally valued relationships. These regulatory processes depend on individual tendencies, but are also co-regulated within relationships—close others shape people's environment and help them appraise events in culturally valued ways—and are afforded by structural conditions—people's daily lives “limit” the opportunities for emotion, and afford certain appraisals. The combined evidence suggests that cultural differences in emotion regulation go well beyond the effortful regulation based on display rules. PMID:23408753

  14. Events and the Ontology of Individuals: Verbs as a Source of Individuating Mass and Count Nouns

    ERIC Educational Resources Information Center

    Barner, David; Wagner, Laura; Snedeker, Jesse

    2008-01-01

    What does mass-count syntax contribute to the interpretation of noun phrases (NPs), and how much of NP meaning is contributed by lexical items alone? Many have argued that count syntax specifies reference to countable individuals (e.g., "cats") while mass syntax specifies reference to unindividuated entities (e.g., "water"). We evaluated this…

  15. Events and the Ontology of Individuals: Verbs as a Source of Individuating Mass and Count Nouns

    ERIC Educational Resources Information Center

    Barner, David; Wagner, Laura; Snedeker, Jesse

    2008-01-01

    What does mass-count syntax contribute to the interpretation of noun phrases (NPs), and how much of NP meaning is contributed by lexical items alone? Many have argued that count syntax specifies reference to countable individuals (e.g., "cats") while mass syntax specifies reference to unindividuated entities (e.g., "water"). We evaluated this…

  16. Signatures of anisotropic sources in the trispectrum of the cosmic microwave background

    SciTech Connect

    Shiraishi, Maresuke; Komatsu, Eiichiro; Peloso, Marco E-mail: komatsu@mpa-garching.mpg.de

    2014-04-01

    Soft limits of N-point correlation functions, in which one wavenumber is much smaller than the others, play a special role in constraining the physics of inflation. Anisotropic sources such as a vector field during inflation generate distinct angular dependence in all these correlators, and introduce a fix privileged direction in our sky. In this paper we focus on the four-point correlator (the trispectrum T). We adopt a parametrization motivated by models in which the inflaton φ is coupled to a vector field through a I{sup 2}(φ)F{sup 2} interaction, namely T{sub ζ}(k{sub 1},k{sub 2},k{sub 3},k{sub 4})≡∑{sub n}d{sub n}[P{sub n}( k-circumflex {sub 1}⋅ k-circumflex {sub 3})+P{sub n}( k-circumflex {sub 1}⋅ k-circumflex {sub 12})+P{sub n}( k-circumflex {sub 3}⋅ k-circumflex {sub 12})]P{sub ζ}(k{sub 1})P{sub ζ}(k{sub 3})P{sub ζ}(k{sub 12})+(23perm), where P{sub n} denotes the Legendre polynomials. This shape is enhanced when the wavenumbers of the diagonals of the quadrilateral are much smaller than the sides, k{sub i}. The coefficient of the isotropic part, d{sub 0}, is equal to τ{sub NL}/6 discussed in the literature. A I{sup 2}(φ)F{sup 2} interaction generates d{sub 2} = 2d{sub 0} which is, in turn, related to the quadrupole modulation parameter of the power spectrum, g{sub *}, as d{sub 2} ≈ 14|g{sub *}|N{sup 2} with N ≈ 60. We show that d{sub 0} and d{sub 2} can be equally well-constrained: the expected 68% CL error bars on these coefficients from a cosmic-variance-limited experiment measuring temperature anisotropy of the cosmic microwave background up to ℓ{sub max} = 2000 are δd{sub 2} ≈ 4δd{sub 0} = 105. Therefore, we can reach |g{sub *}| = 10{sup −3} by measuring the angle-dependent trispectrum. The current upper limit on τ{sub NL} from the Planck temperature maps yields |g{sub *}| < 0.02 (95% CL)

  17. Signatures of anisotropic sources in the squeezed-limit bispectrum of the cosmic microwave background

    SciTech Connect

    Shiraishi, Maresuke; Komatsu, Eiichiro; Peloso, Marco; Barnaby, Neil E-mail: komatsu@mpa-garching.mpg.de E-mail: barnaby@physics.umn.edu

    2013-05-01

    The bispectrum of primordial curvature perturbations in the squeezed configuration, in which one wavenumber, k{sub 3}, is much smaller than the other two, k{sub 3} << k{sub 1} ≈ k{sub 2}, plays a special role in constraining the physics of inflation. In this paper we study a new phenomenological signature in the squeezed-limit bispectrum: namely, the amplitude of the squeezed-limit bispectrum depends on an angle between k{sub 1} and k{sub 3} such that B{sub ζ}(k{sub 1},k{sub 2},k{sub 3}) → 2Σ{sub L}c{sub L}P{sub L}( k-circumflex {sub 1}· k-circumflex {sub 3})P{sub ζ}(k{sub 1})P{sub ζ}(k{sub 3}), where P{sub L} are the Legendre polynomials. While c{sub 0} is related to the usual local-form f{sub NL} parameter as c{sub 0} = 6f{sub NL}/5, the higher-multipole coefficients, c{sub 1}, c{sub 2}, etc., have not been constrained by the data. Primordial curvature perturbations sourced by large-scale magnetic fields generate non-vanishing c{sub 0}, c{sub 1}, and c{sub 2}. Inflation models whose action contains a term like I(φ){sup 2}F{sup 2} generate c{sub 2} = c{sub 0}/2. A recently proposed ''solid inflation'' model generates c{sub 2} >> c{sub 0}. A cosmic-variance-limited experiment measuring temperature anisotropy of the cosmic microwave background up to l{sub max} = 2000 is able to measure these coefficients down to δc{sub 0} = 4.4, δc{sub 1} = 61, and δc{sub 2} = 13 (68% CL). We also find that c{sub 0} and c{sub 1}, and c{sub 0} and c{sub 2}, are nearly uncorrelated. Measurements of these coefficients will open up a new window into the physics of inflation such as the existence of vector fields during inflation or non-trivial symmetry structure of inflaton fields. Finally, we show that the original form of the Suyama-Yamaguchi inequality does not apply to the case involving higher-spin fields, but a generalized form does.

  18. Assessment of ambient background concentrations of elements in soil using combined survey and open-source data.

    PubMed

    Mikkonen, Hannah G; Clarke, Bradley O; Dasika, Raghava; Wallis, Christian J; Reichman, Suzie M

    2017-02-15

    Understanding ambient background concentrations in soil, at a local scale, is an essential part of environmental risk assessment. Where high resolution geochemical soil surveys have not been undertaken, soil data from alternative sources, such as environmental site assessment reports, can be used to support an understanding of ambient background conditions. Concentrations of metals/metalloids (As, Mn, Ni, Pb and Zn) were extracted from open-source environmental site assessment reports, for soils derived from the Newer Volcanics basalt, of Melbourne, Victoria, Australia. A manual screening method was applied to remove samples that were indicated to be contaminated by point sources and hence not representative of ambient background conditions. The manual screening approach was validated by comparison to data from a targeted background soil survey. Statistical methods for exclusion of contaminated samples from background soil datasets were compared to the manual screening method. The statistical methods tested included the Median plus Two Median Absolute Deviations, the upper whisker of a normal and log transformed Tukey boxplot, the point of inflection on a cumulative frequency plot and the 95th percentile. We have demonstrated that where anomalous sample results cannot be screened using site information, the Median plus Two Median Absolute Deviations is a conservative method for derivation of ambient background upper concentration limits (i.e. expected maximums). The upper whisker of a boxplot and the point of inflection on a cumulative frequency plot, were also considered adequate methods for deriving ambient background upper concentration limits, where the percentage of contaminated samples is <25%. Median ambient background concentrations of metals/metalloids in the Newer Volcanic soils of Melbourne were comparable to ambient background concentrations in Europe and the United States, except for Ni, which was naturally enriched in the basalt-derived soils of

  19. Events and the ontology of individuals: verbs as a source of individuating mass and count nouns.

    PubMed

    Barner, David; Wagner, Laura; Snedeker, Jesse

    2008-02-01

    What does mass-count syntax contribute to the interpretation of noun phrases (NPs), and how much of NP meaning is contributed by lexical items alone? Many have argued that count syntax specifies reference to countable individuals (e.g., cats) while mass syntax specifies reference to unindividuated entities (e.g., water). We evaluated this claim using the quantity judgment method, and tested the interpretation of words used in mass and count syntax that described either protracted, "durative" events (e.g., mass: some dancing; count: a dance), or instantaneous, "punctual" events (e.g., mass: some jumping; count: a jump). For durative words, participants judged, for example, that six brief dances are more dances but less dancing than two long dances, thus showing a significant difference in their interpretation of the count and mass usages. However, for punctual words, participants judged, for example, that six small jumps are both more jumps and more jumping than two long jumps, resulting in no difference due to mass-count syntax. Further, when asked which dimensions are important for comparing quantities of durative and punctual events, participants ranked number as first in importance for durative and punctual words presented in count syntax, but also for punctual words presented in mass syntax. These results indicate that names for punctual events individuate when used in either mass or count syntax, and thus provide evidence against the idea that mass syntax forces an unindividuated construal. They also indicate that event punctuality as encoded by verbs is importantly linked to the individuation of NPs, and may access a common underlying ontology of individuals.

  20. Total annoyance from an industrial noise source with a main spectral component combined with a background noise.

    PubMed

    Alayrac, M; Marquis-Favre, C; Viollon, S

    2011-07-01

    When living close to an industrial plant, people are exposed to a combination of industrial noise sources and a background noise composed of all the other noise sources in the environment. As a first step, noise annoyance indicators in laboratory conditions are proposed for a single exposure to an industrial noise source. The second step detailed in this paper involves determining total annoyance indicators in laboratory conditions for ambient noises composed of an industrial noise source and a background noise. Two types of steady and permanent industrial noise sources are studied: low frequency noises with a main spectral component at 100 Hz, and noises with a main spectral component in middle frequencies. Five background noises are assessed so as to take into account different sound environments which can usually be heard by people living around an industrial plant. One main conclusion of this study is that two different analyses are necessary to determine total annoyance indicators for this type of ambient noise, depending on the industrial noise source composing it. Therefore, two total annoyance indicators adapted to the ambient noises studied are proposed. © 2011 Acoustical Society of America

  1. Background gas density and beam losses in NIO1 beam source

    NASA Astrophysics Data System (ADS)

    Sartori, E.; Veltri, P.; Cavenago, M.; Serianni, G.

    2016-02-01

    NIO1 (Negative Ion Optimization 1) is a versatile ion source designed to study the physics of production and acceleration of H- beams up to 60 keV. In ion sources, the gas is steadily injected in the plasma source to sustain the discharge, while high vacuum is maintained by a dedicated pumping system located in the vessel. In this paper, the three dimensional gas flow in NIO1 is studied in the molecular flow regime by the Avocado code. The analysis of the gas density profile along the accelerator considers the influence of effective gas temperature in the source, of the gas temperature accommodation by collisions at walls, and of the gas particle mass. The calculated source and vessel pressures are compared with experimental measurements in NIO1 during steady gas injection.

  2. Background gas density and beam losses in NIO1 beam source

    SciTech Connect

    Sartori, E. Veltri, P.; Serianni, G.; Cavenago, M.

    2016-02-15

    NIO1 (Negative Ion Optimization 1) is a versatile ion source designed to study the physics of production and acceleration of H- beams up to 60 keV. In ion sources, the gas is steadily injected in the plasma source to sustain the discharge, while high vacuum is maintained by a dedicated pumping system located in the vessel. In this paper, the three dimensional gas flow in NIO1 is studied in the molecular flow regime by the Avocado code. The analysis of the gas density profile along the accelerator considers the influence of effective gas temperature in the source, of the gas temperature accommodation by collisions at walls, and of the gas particle mass. The calculated source and vessel pressures are compared with experimental measurements in NIO1 during steady gas injection.

  3. Background information on sources of low-level radionuclide emissions to air

    SciTech Connect

    Corbit, C.D.; Herrington, W.N.; Higby, D.P.; Stout, L.A.; Corley, J.P.

    1983-09-01

    This report provides a general description and reported emissions for eight low-level radioactive source categories, including facilties that are licensed by the Nuclear Regulatory Commission (NRC) and Agreement States, and non-Department of Energy (DOE) federal facilities. The eight categories of low-level radioactive source facilities covered by this report are: research and test reactors, accelerators, the radiopharmaceutical industry, source manufacturers, medical facilities, laboratories, naval shipyards, and low-level commercial waste disposal sites. Under each category five elements are addressed: a general description, a facility and process description, the emission control systems, a site description, and the radionuclides released to air (from routine operations).

  4. On Compton reflection in the sources of the cosmic X-ray background

    NASA Technical Reports Server (NTRS)

    Zdziarski, Andrzej A.; Zycki, Piotr T.; Svensson, Roland; Boldt, Elihu

    1993-01-01

    Consideration is given to recent models for the cosmic X-ray background that assume that it originates from unresolved AGN emitting spectra due to enhanced Compton reflection of a power-law photon spectrum incident on cold matter. The parameter space of the Compton reflection model is studied, and the allowed parameter space is found to be severely constrained by physical and cosmological effects. For an incident power-law energy index alpha is greater than about 1, the X-ray peak in the observed spectrum from a population of AGN is necessarily at an energy less than that of the observed peak. Two examples of improved fits to the X-ray background are shown. It is concluded that the Compton reflection models proposed to date do not provide a straightforward explanation of the X-ray background spectrum.

  5. How Far Away Are the Sources of IceCube Neutrinos? Constraints from the Diffuse Teraelectronvolt Gamma-ray Background

    NASA Astrophysics Data System (ADS)

    Chang, Xiao-Chuan; Liu, Ruo-Yu; Wang, Xiang-Yu

    2016-07-01

    The nearly isotropic distribution of teraelectronvolt to petaelectronvolt neutrinos recently detected by the IceCube Collaboration suggests that they come from sources at a distance beyond our Galaxy, but how far away they are is largely unknown because of a lack of any associations with known sources. In this paper, we propose that the cumulative TeV gamma-ray emission accompanying the production of neutrinos can be used to constrain the distance of these neutrino sources, since the opacity of TeV gamma rays due to absorption by the extragalactic background light depends on the distance these TeV gamma rays have traveled. As the diffuse extragalactic TeV background measured by Fermi is much weaker than the expected cumulative flux associated with IceCube neutrinos, the majority of IceCube neutrinos, if their sources are transparent to TeV gamma rays, must come from distances larger than the horizon of TeV gamma rays. We find that above 80% of the IceCube neutrinos should come from sources at redshift z > 0.5. Thus, the chance of finding nearby sources correlated with IceCube neutrinos would be small. We also find that, to explain the flux of neutrinos under the TeV gamma-ray emission constraint, the redshift evolution of neutrino source density must be at least as fast as the cosmic star formation rate.

  6. Analysis of XMM-Newton Data from Extended Sources and the Diffuse X-Ray Background

    NASA Technical Reports Server (NTRS)

    Snowden, Steven

    2011-01-01

    Reduction of X-ray data from extended objects and the diffuse background is a complicated process that requires attention to the details of the instrumental response as well as an understanding of the multiple background components. We present methods and software that we have developed to reduce data from XMM-Newton EPIC imaging observations for both the MOS and PN instruments. The software has now been included in the Science Analysis System (SAS) package available through the XMM-Newton Science Operations Center (SOC).

  7. Food sources of individual plasma phospholipid trans fatty acid isomers: the Cardiovascular Health Study12345

    PubMed Central

    King, Irena B; Lemaitre, Rozenn N; Rimm, Eric B; Sacks, Frank; Song, Xiaoling; Siscovick, David S; Mozaffarian, Dariush

    2010-01-01

    Background: The overall consumption of trans fatty acids (TFAs) increases the risk of coronary artery disease. However, multiple TFA isomers exist, each with potentially different health effects. Different food sources of these specific TFA isomers are not well established. Objective: Our objective was to determine the major independent food sources of specific TFA isomers. Design: We investigated relations of major potential food sources of TFAs, as assessed by serial food-frequency questionnaires, with 10 plasma phospholipid TFA isomers [5 trans (t-) 18:1, 3 t-18:2, and 2 t-16:1] in 3330 older adults in the Cardiovascular Health Study, a community-based multicenter cohort. Stepwise regression was used to identify independent major food sources of individual plasma phospholipid TFA isomers, which were adjusted for demographic, lifestyle, and dietary factors. Results: All 5 t-18:1 isomers were similarly associated with foods commonly made with partially hydrogenated vegetable oils (PHVOs), including biscuits (0.51 higher SD of total 18:1 fatty acid concentrations per serving/d, P < 0.01), chips and/or popcorn (0.33 higher SD per serving/d, P = 0.02), margarine (0.32 higher SD per serving/d, P < 0.001), fried foods (0.32 higher SD per serving/d, P = 0.04), and bakery foods (0.23 higher SD per serving/d, P = 0.02). Each of the t-18:2 isomers were associated only with bakery foods (0.50 higher SD of total 18:2 fatty acid concentrations per serving/d, P < 0.001). Ruminant foods were major correlates of t-16:1n−7, including red meats (0.72 higher SD per serving/d, P < 0.001), butter (0.43 higher SD per serving/d, P < 0.001), and higher-fat dairy (0.37 higher SD per serving/d, P < 0.001). In contrast, t-16:1n−9 were derived mainly from margarine (0.31 higher SD per serving/d, P < 0.001). Conclusions: t-18:1 Isomers are similarly derived from multiple PHVO-containing foods. In contrast, t-18:2 and t-16:1n−9 isomers are derived from more-specific types of PHVO

  8. Inverse Source Problem in Non-homogeneous and Metamaterial Background Media: Antenna Synthesis and Performance Bounds

    DTIC Science & Technology

    2009-02-28

    each one), as governed by a for- mally tractable source-energy cost function that is physically motivated by ohmic loss control . The derived theory ...The main accomplishments of this work are: • The development of a new theory of the full vector electromagnetic inverse source problem in non...plus reactive power tun- ing). • The demonstration, via many computer simulations, of the effective- ness of this theory as a tool for antenna

  9. Sources and levels of background noise in the NASA Ames 40- by 80-foot wind tunnel

    NASA Technical Reports Server (NTRS)

    Soderman, Paul T.

    1988-01-01

    Background noise levels are measured in the NASA Ames Research Center 40- by 80-Foot Wind Tunnel following installation of a sound-absorbent lining on the test-section walls. Results show that the fan-drive noise dominated the empty test-section background noise at airspeeds below 120 knots. Above 120 knots, the test-section broadband background noise was dominated by wind-induced dipole noise (except at lower harmonics of fan blade-passage tones) most likely generated at the microphone or microphone support strut. Third-octave band and narrow-band spectra are presented for several fan operating conditions and test-section airspeeds. The background noise levels can be reduced by making improvements to the microphone wind screen or support strut. Empirical equations are presented relating variations of fan noise with fan speed or blade-pitch angle. An empirical expression for typical fan noise spectra is also presented. Fan motor electric power consumption is related to the noise generation. Preliminary measurements of sound absorption by the test-section lining indicate that the 152 mm thick lining will adequately absorb test-section model noise at frequencies above 300 Hz.

  10. Rater Language Background as a Source of Measurement Error in the Testing of English Language Learners

    ERIC Educational Resources Information Center

    Kachchaf, Rachel; Solano-Flores, Guillermo

    2012-01-01

    We examined how rater language background affects the scoring of short-answer, open-ended test items in the assessment of English language learners (ELLs). Four native English and four native Spanish-speaking certified bilingual teachers scored 107 responses of fourth- and fifth-grade Spanish-speaking ELLs to mathematics items administered in…

  11. Source Apportionment of the Summer Time Carbonaceous Aerosol at Nordic Rural Background Sites

    EPA Science Inventory

    In the present study, natural and anthropogenic sources of particulate organic carbon (OCp) and elemental carbon (EC) have been quantified based on weekly filter samples of PM10 (particles with aerodynamic diameter <10µ collected at four Nordic rural backgro...

  12. Source Apportionment of the Summer Time Carbonaceous Aerosol at Nordic Rural Background Sites

    EPA Science Inventory

    In the present study, natural and anthropogenic sources of particulate organic carbon (OCp) and elemental carbon (EC) have been quantified based on weekly filter samples of PM10 (particles with aerodynamic diameter <10µ collected at four Nordic rural backgro...

  13. Background pressure effects on EUV source efficiency and produced debris characteristics

    NASA Astrophysics Data System (ADS)

    Sizyuk, Tatyana

    2017-03-01

    The cost of future computer chips, among other things, will depend on the performance of EUV sources and on the duration of the efficient operation and lifetime of nanolithography devices. While the efficiency of the sources is continuously being improved, their operational cycle is still highly restricted due to optical mirrors degradation as well as necessity of cleaning chamber environment and components. One of the potential problems of EUV sources for high volume manufacture (HVM) regimes can be related to the contamination of chamber environment by products of preceding laser pulse/droplet interactions. Implementation of high, 100 kHz and higher, repetition rate of devices for Sn droplets and laser pulses generation can cause high accumulation of tin in the chamber in the form of vapor/clusters. Possible tin accumulation in the chamber in dependence on laser parameters and mitigation system efficiency was evaluated. Then, the effects of various pressures of tin vapor on the CO2 and Nd:YAG laser beams propagation and on the size, the intensity, and the efficiency of EUV sources produced were studied.

  14. Financial Information Source, Knowledge, and Practices of College Students from Diverse Backgrounds

    ERIC Educational Resources Information Center

    Mimura, Yoko; Koonce, Joan; Plunkett, Scott W.; Pleskus, Lindsey

    2015-01-01

    Using cross-sectional data, we examined the financial information sources, financial knowledge, and financial practices of young adults, many of whom are first generation college students, ethnic minorities, and immigrants or children of immigrants. Participants (n = 1,249) were undergraduate students at a large regional comprehensive university.…

  15. The Fermi -Lat High-Latitude Survey: Source Count Distributions And The Origin Of The Extragalactic Diffuse Background

    DOE PAGES

    Abdo, A. A.

    2010-08-11

    This is the first of a series of papers aimed at characterizing the populations detected in the high-latitude sky of the Fermi-LAT survey. In this work, we focus on the intrinsic spectral and flux properties of the source sample. We show that when selection effects are properly taken into account, Fermi sources are on average steeper than previously found (e.g., in the bright source list) with an average photon index of 2.40 ± 0.02 over the entire 0.1-100 GeV energy band. We confirm that flat spectrum radio quasars have steeper spectra than BL Lacertae objects with an average index ofmore » 2.48 ± 0.02 versus 2.18 ± 0.02. Using several methods, we build the deepest source count distribution at GeV energies, deriving that the intrinsic source (i.e., blazar) surface density at F 100 ≥ 10–9 ph cm–2 s–1 is 0.12+0.03 –0.02 deg–2. The integration of the source count distribution yields that point sources contribute 16(±1.8)% (±7% systematic uncertainty) of the GeV isotropic diffuse background. At the fluxes currently reached by LAT, we can rule out the hypothesis that pointlike sources (i.e., blazars) produce a larger fraction of the diffuse emission.« less

  16. Urban background levels of particle number concentration and sources in Vilnius, Lithuania

    NASA Astrophysics Data System (ADS)

    Byčenkienė, Steigvilė; Plauškaitė, Kristina; Dudoitis, Vadimas; Ulevicius, Vidmantas

    2014-06-01

    This study presents results of research on urban aerosol particles with a focus on the aerosol particle number concentration (PNC) and the particle size distribution. The real time measurements of aerosol PNC (> 4.5 nm) and number size distributions (9-840 nm) were performed. The seasonal variations essentially comprised the minimum monthly mean in October 2010 (3400 ± 3000 cm- 3) and the maximum in April 2011 (19,000 ± 15,000 cm- 3). The mean annual PNC was 10,000 ± 8000 cm- 3 with an average mode size of 30-50 nm. The presence of strong diurnal patterns in aerosol PNC was evident as a direct effect of three sources of aerosol particles (nucleation, traffic, and residential heating). Hybrid receptor modeling potential source contribution function (PSCF) and concentration weighted trajectory (CWT) were used by incorporating 72-h backward trajectories and measurements of PNC in Vilnius. The results of trajectory clustering and the PSCF method demonstrated that possible additional source areas contributing to the elevated particle number concentration in Vilnius could be industrial areas in central Europe. Principal component analysis (PCA) revealed highest loadings for PNC, PM10, NOx, NO, NO2 and SO2 concentrations, indicating combustion processes occurring in vehicle engines and use of sulfur-containing fossil fuels for residential heating.

  17. LSO background radiation as a transmission source using time of flight.

    PubMed

    Rothfuss, Harold; Panin, Vladimir; Moor, Andrew; Young, John; Hong, Inki; Michel, Christian; Hamill, James; Casey, Michael

    2014-09-21

    LSO scintillators (Lu2Sio5:Ce) have a background radiation which originates from the isotope Lu-176 that is present in natural occurring lutetium. The decay that occurs in this isotope is a beta decay that is in coincidence with cascade gamma emissions with energies of 307,202 and 88 keV. The coincidental nature of the beta decay with the gamma emissions allow for separation of emission data originating from a positron annihilation event from transmission type data from the Lu-176 beta decay. By using the time of flight information, and information of the chord length between two LSO pixels in coincidence as a result of a beta emission and emitted gamma, a second time window can be set to observe transmission events simultaneously to emission events. Using the time when the PET scanner is not actively acquiring positron emission data, a continuous blank can be acquired and used to reconstruct a transmission image. With this blank and the measured transmission data, a transmission image can be reconstructed. This reconstructed transmission image can be used to perform emission data corrections such as attenuation correction and scatter corrections or starting images for algorithms that estimate emission and attenuation simultaneously. It is observed that the flux of the background activity is high enough to create useful transmission images with an acquisition time of 10 min.

  18. LSO background radiation as a transmission source using time of flight

    NASA Astrophysics Data System (ADS)

    Rothfuss, Harold; Panin, Vladimir; Moor, Andrew; Young, John; Hong, Inki; Michel, Christian; Hamill, James; Casey, Michael

    2014-09-01

    LSO scintillators (Lu2Sio5:Ce) have a background radiation which originates from the isotope Lu-176 that is present in natural occurring lutetium. The decay that occurs in this isotope is a beta decay that is in coincidence with cascade gamma emissions with energies of 307,202 and 88 keV. The coincidental nature of the beta decay with the gamma emissions allow for separation of emission data originating from a positron annihilation event from transmission type data from the Lu-176 beta decay. By using the time of flight information, and information of the chord length between two LSO pixels in coincidence as a result of a beta emission and emitted gamma, a second time window can be set to observe transmission events simultaneously to emission events. Using the time when the PET scanner is not actively acquiring positron emission data, a continuous blank can be acquired and used to reconstruct a transmission image. With this blank and the measured transmission data, a transmission image can be reconstructed. This reconstructed transmission image can be used to perform emission data corrections such as attenuation correction and scatter corrections or starting images for algorithms that estimate emission and attenuation simultaneously. It is observed that the flux of the background activity is high enough to create useful transmission images with an acquisition time of 10 min.

  19. Vapor intrusion attenuation factors relative to subslab and source, reconsidered in light of background data

    PubMed Central

    Yao, Yijun; Wu, Yun; Suuberg, Eric M.; Provoost, Jeroen; shen, Rui; Ma, Jianqing; Liu, Jing

    2016-01-01

    The basis upon which recommended attenuation factors for vapor intrusion (VI) have been derived are reconsidered. By making a fitting curve to the plot showing the dependence of observed indoor air concentration (cin) on subslab concentration (css) for residences in EPA database, an analytical equation is obtained to identify the relationship among cin, css and the averaged background level. The new relationship indicates that subslab measurements may serve as a useful guide only if css is above 500 μg / m3. Otherwise, cin is independent of css, with a distribution in good agreements with other studies of background levels. Therefore, employing this screening value (500 μg / m3), new contaminant concentration attenuation factors are proposed for VI, and the values for groundwater-to-indoor and subslab-to-indoor air concentration attenuation factors are 0.004 and 0.02, respectively. The former is applied to examining the reported temporal variations of cin obtained during a long-term monitoring study. The results show that using this new groundwater-to-indoor air concentration attenuation factor also provides a reasonably conservative estimate of cin. PMID:25618001

  20. Background PM2.5 source apportionment in the remote Northwestern United States

    NASA Astrophysics Data System (ADS)

    Hadley, Odelle L.

    2017-10-01

    This study used the Environmental Protection Agency's positive matrix factorization model (EPA PMF5.0) to identify five primary source factors contributing to the ambient PM2.5 concentrations at Cheeka Peak Atmospheric Observatory (CPO), Neah Bay WA between January 2011 and December 2014. CPO is home to both an IMPROVE (Interagency Monitoring for Protected Visual Environments) and a NCore multi-pollutant monitoring site. Chemically resolved particulate data from the IMPROVE site was the input data to EPA PMF5.0 and the resulting source factors were derived solely from these data. Solutions from the model were analyzed in context with trace gas and meteorological data collected at the NCore site located roughly 10 m away. Seasonal and long-term trends were analyzed for all five factors and provide the first complete source apportionment analysis of PM2.5 at this remote location. The first factor, identified as marine-traffic residual fuel oil (RFO), was the highest contributor to PM2.5 during late summer. Over the 4-year analysis, the RFO percent contribution to total PM2.5 declined. This is consistent with previous studies and may be attributed to regulations restricting the sulfur content of ship fuel. Biomass combustion emissions (BMC) and sea salt were the largest PM2.5 sources observed at CPO in winter, accounting for over 80% of the fine particulate. BMC accounted for a large percent of the fine particulate pollution when winds were easterly, or continental. Sea salt was the dominant winter factor when winds blew from the west. Measured trace carbon monoxide (CO) and reactive nitrogen species (NOy) were most strongly correlated with the BMC factor and continental winds. The fourth factor was identified as aged crustal material, or dust. In all three years, dust peaked in the spring and was associated exclusively with north-easterly winds. The last factor was identified as aged sea salt mixed with nitrate, sulfate, and other components common to RFO and BMC

  1. Extra-individual sources of social support as described by adults with mild intellectual disabilities.

    PubMed

    Lunsky, Yona; Neely, Lynn C

    2002-08-01

    The extra-individual social support responses provided by adults with intellectual disabilities on a social support survey were examined. Felton and Berry (1992) argued that extra-individual social support, support from larger than individual entities, is a valid source of social support for older adults. We hypothesized that extra-individual support would also be relevant to adults with intellectual disabilities. Results showed that 43% of participants with intellectual disabilities listed extra-individual support sources in their social networks or as providers of one of several support functions. The most popular forms of extra-individual support were those from "staff" and "work." Findings are discussed in terms of implications for social support measurement for persons with intellectual disabilities.

  2. Stray light test station for measuring point source transmission and thermal background of visible and infrared sensors

    NASA Astrophysics Data System (ADS)

    Peterson, Gary L.

    2008-08-01

    Breault Research Organization has designed and built a stray light test station. The station measures the point source transmission and background thermal irradiance of visible and infrared sensors. Two beam expanders, including a large 0.89 meter spherical mirror, expand and collimate light from laser sources at 0.658 and 10.6 µm. The large mirror is mounted on a gimbal to illuminate sensors at off-axis angles from 0° to 10°, and azimuths from 0° to 180°. Sensors with apertures as large as 0.3 meters can be tested with the existing facility. The large mirror is placed within a vacuum chamber so cryogenic infrared sensors can be tested in a vacuum environment. A dark cryogenic cold plate can be translated into the field of view of a sensor to measure its background thermal irradiance.

  3. Flat-spectrum radio source C1 in M33 is a background radio galaxy

    SciTech Connect

    Reynolds, S.P.; Fix, J.D.

    1988-10-01

    A candidate Crab-like supernova remnant in M33 discovered in a high-resolution survey of compact radio sources (Reynolds and Fix, 1987) has been observed. VLA observations at 1465 and 4885 MHz show that it is simply the flat-spectrum core of a completely normal double-lobed radio galaxy. This eliminates the last candidate Crab-like object in M33 whose size and brightness do not at all resemble those of the Crab Nebula, and confirms the dearth of Crab-like supernova remnants reported earlier. 7 references.

  4. Lignin-derived phenols in Houston aerosols: implications for natural background sources.

    PubMed

    Shakya, Kabindra M; Louchouarn, Patrick; Griffin, Robert J

    2011-10-01

    Solvent-extractable monomeric methoxyphenols in aerosol samples conventionally have been used to indicate the influence of biomass combustion. In addition, the presence of lignin oxidation products (LOP), derived from the CuO oxidation of vascular plant organic matter, can help trace the source and inputs of primary biological particles in aerosols. Ambient aerosols (coarse and fine) collected in Houston during summer 2010 were analyzed by gas chromatography-mass spectrometry to characterize monomeric and polymeric sources of LOPs. This is the first time polymeric forms of the LOPs have been characterized in ambient aerosols. The absence or small concentrations of solvent-extractable monomeric LOPs and levoglucosan isomers point to the limited influence of biomass burning during the sampling period. The trace levels of anhydrosugar concentrations most likely result from long-range transport. This observation is supported by the absence of co-occurring lignin monomers that undergo photochemical degradation during transport. The larger concentration (142 ng m(-3)) of lignin polymers in coarse aerosols shows the relative importance of primary biological aerosol particles, even in the urban atmosphere. The LOP parameters suggest a predominant influence from woody tissue of angiosperms, with minor influence from soft tissues, gymnosperms, and soil organic matter.

  5. An extended galactic population of low-luminosity x-ray sources (CVs?) and the diffuse x-ray background

    NASA Technical Reports Server (NTRS)

    Maoz, Eyal; Grindlay, Jonathan E.

    1995-01-01

    The incompatibility of the properties of the X-ray background (XRB) with active galactic nuclei (AGNs) contributing approximately greater than 60% at energies of a few keV has often been interpreted as being due to a substantial contribution of a new population of yet unrecognized X-ray sources. The existence of such population has been recently suggested also by an analysis of very deep ROSAT observations which revealed a considerable excess of faint X-ray sources over that expected from QSO evolution models, and that the average spectrum of the resolved sources becomes harder with decreasing flux limit. These sources could be extragalactic in origin, but if they make a substantial contribution to the XRB then they must exhibit much weaker clustering than galaxies or QSOs in order to be consistent with the stringent constraints on source clustering imposed by autocorrelation analyses of the unresolved XRB. We investigate the possibility that the indicated new population of X-ray sources is Galactic in origin. Examining spherical halo and thick disk distributions, we derive the allowed properties of such populations which would resolve the discrepancy found in the number counts of faint sources and be consistent with observational constraints on the total background intensity, the XRB anisotropy, the number of unidentified bright sources, the Galaxy's total X-ray luminosity, and with the results of fluctuation analyses of the unresolved XRB. We find that a flattened Galactic halo (or a thick disk) distribution with a scale height of a few kpc is consistent with all the above requirements. The typical X-ray luminosity of the sources is approximately equal to 10(exp 30-31)ergs/s in the 0.5-2 keV band, the number density of sources in the solar vicinity is approximately 10(exp -4.5)pc(exp -3), their total number in the Galaxy is approximately 10(exp 8.5), and their total contribution to the Galaxy's X-ray luminosity is approximately 10(exp 39) ergs/s. We discuss the

  6. Determination of the health hazards due to background radiation sources in the city of Adapazari, Northwestern Turkey.

    PubMed

    Kapdan, Enis; Altinsoy, Nesrin; Karahan, Gursel; Taskin, Halim

    2011-03-01

    Human body is exposed to ionising radiations both internally and externally by mainly high-energy cosmic ray particles incident on the earth's atmosphere and radioactive nuclides that originated in the earth's crust. The main objective of this study is to assess the health hazards due to environmental radiation sources in the city of Adapazari, one of the most important industrial cities of the country, Northwestern Turkey. For this purpose, natural radiation sources, external terrestrial radiations, cosmic radiations, and inhalation exposures have been investigated. The annual average external terrestrial radiation doses were determined as 0.08 and 0.35 mSv at outdoor and indoor atmospheres, respectively. The annual average cosmic radiation doses were found to be 0.08 and 0.05 mSv for directly ionising photon components and neutron components, respectively. The annual average inhalation exposure doses due to radon and thoron were obtained as 1.42 and 0.19 mSv, respectively, in the region. The annual average effective dose due to natural radiation sources was determined as a total of 2.35 mSv with the predetermined ingestion radiation dose. The lifetime cancer risk due to the background ionising radiations has been determined as 0.9×10(-2) for the residents of the Adapazari city, with the average lifespan of 70 years. The results of the effective doses due to background radiation sources in the region and the worldwide averages were discussed.

  7. Sources and mixing state of summertime background aerosol in the north-western Mediterranean basin

    NASA Astrophysics Data System (ADS)

    Arndt, Jovanna; Sciare, Jean; Mallet, Marc; Roberts, Greg C.; Marchand, Nicolas; Sartelet, Karine; Sellegri, Karine; Dulac, François; Healy, Robert M.; Wenger, John C.

    2017-06-01

    An aerosol time-of-flight mass spectrometer (ATOFMS) was employed to provide real-time single particle mixing state and thereby source information for aerosols impacting the western Mediterranean basin during the ChArMEx-ADRIMED and SAF-MED campaigns in summer 2013. The ATOFMS measurements were made at a ground-based remote site on the northern tip of Corsica. Twenty-seven distinct ATOFMS particle classes were identified and subsequently grouped into eight general categories: EC-rich (elemental carbon), K-rich, Na-rich, amines, OC-rich (organic carbon), V-rich, Fe-rich and Ca-rich particles. Mass concentrations were reconstructed for the ATOFMS particle classes and found to be in good agreement with other co-located quantitative measurements (PM1, black carbon (BC), organic carbon, sulfate mass and ammonium mass). Total ATOFMS reconstructed mass (PM2. 5) accounted for 70-90 % of measured PM10 mass and was comprised of regionally transported fossil fuel (EC-rich) and biomass burning (K-rich) particles. The accumulation of these transported particles was favoured by repeated and extended periods of air mass stagnation over the western Mediterranean during the sampling campaigns. The single particle mass spectra proved to be valuable source markers, allowing the identification of fossil fuel and biomass burning combustion sources, and was therefore highly complementary to quantitative measurements made by Particle into Liquid Sampler ion chromatography (PILS-IC) and an aerosol chemical speciation monitor (ACSM), which have demonstrated that PM1 and PM10 were comprised predominantly of sulfate, ammonium and OC. Good temporal agreement was observed between ATOFMS EC-rich and K-rich particle mass concentrations and combined mass concentrations of BC, sulfate, ammonium and low volatility oxygenated organic aerosol (LV-OOA). This combined information suggests that combustion of fossil fuels and biomass produced primary EC- and OC-containing particles, which then

  8. Diversity of Students' background as a source for improving teaching Physics at a Liberal Arts Institution

    NASA Astrophysics Data System (ADS)

    Agrest, Mikhail

    2001-11-01

    Presented work is dedicated to improvement of teaching-learning process and classroom time utilization. What should students carry with them from the classroom? Enthusiasm of their teacher, understanding of the basic concepts, understanding of what they should work on at home and, of course, some notes Teaching materials, which relate concepts of Physics to each other and to a variety of concepts in other areas of knowledge and human activity were developed. This approach is based on my experience of interacting with students with diversity of backgrounds, educational goals and objectives. Those include Business and Politics, Literature and Media, everyday family and College life, etc. A supplement workbook based on teaching materials was developed to be available for students to make notes during the lectures. This method was tested in Introductory Physics classes at the College of Charleston during some past years. The teaching-learning effectiveness has been increased and positive feedback was received from students and faculty at the College and some other Universities.

  9. First assessment on NOx sources for a regional background site of North China using isotopic analysis linked with modelling

    NASA Astrophysics Data System (ADS)

    Zong, Zheng; Wang, Xiaoping; Tian, Chongguo

    2017-04-01

    Nitrogen oxides (NOx, including NO and NO2) play an important role in the formation of new particles. Thus NOx emission reduction is one of the most critical steps to improve the air quality, especially in severe air-polluted areas (e.g. the North China). In this study, the sources and conversion mechanisms of NOx were explored at Beihuangcheng Island (BH), a regional background site in North China. Results showed humidity and oxidants were important promoters for the conversion of NOx to nitrate (NO3-) in the atmosphere. Based on nitrogen isotope and an improved Bayesian mixing model, 61.85 ± 2.50%, 24.46 ± 4.02% and 13.69 ± 3.18% of NOx could be attributed to mobile source, coal combustion and biomass burning, respectively, which indicated that mobile source was the primary source for NOx on BH. Seasonally, mobile source was dominant contributor in summer (75.24 ± 5.29%), spring (61.53 ± 4.66%) and autumn (58.72 ± 4.17%). While residential coal combustion confirmed by Mann-Kendall test and moving simulation contributed a main portion of 71.75 ± 11.35% in winter. This work indicated that isotope-modelling is a promising tool for partitioning NOx sources, and provided policy maker with the valuable insight into the NOx reduction in North China.

  10. 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

  11. The emerging source of polycyclic aromatic hydrocarbons from mining in the Tibetan Plateau: Distributions and contributions in background soils.

    PubMed

    Li, Jun; Yuan, Guo-Li; Li, Ping; Sun, Yong; Yu, Hong-Hui; Wang, Gen-Hou

    2017-04-15

    The Tibetan Plateau (TP) serves as the background for persistent organic pollutants around the world. In addition to outside sources, local sources greatly contribute to the environment of the TP in recent decades. Mining activity could serve as an emerging source of polycyclic aromatic hydrocarbons (PAHs), although this issue has been neglected in the TP until now. To investigate the distributions and contributions of PAHs transported from mining activity, forty-one surface soil samples along six sampling directions were collected at a regular distance from the Jiama mining area (JMA) of the TP at altitudes between 3726 and 4863m. The total concentration of 16 PAHs was 52.34±22.58ng/g. The result of the source identification suggested that mining activity represented the primary source for heavy molecular weight (HMW) PAHs in soils, while light molecular weight (LMW) and middle molecular weight (MMW) PAHs were contributed by multiple sources. For HMW PAHs, the concentrations and proportions decreased logarithmically with transport distance from the JMA. Furthermore, the transport distance of HMW PAHs was found to be affected by the prevailing wind direction. In addition to transport from the source area, the distributions of LMW and MMW PAHs were also influenced by the altitude. In the impact area of Jiama mining activity, the soil mass inventory was estimated to be 6.4±0.8tons for HMW PAHs. In future decades, HMW PAHs emitted from Jiama mining activity are projected to exceed 5% of the annual local emission in the TP. Our study evidenced that Tibetan mining activity serves as an important emerging source of PAHs, which would be transported within the TP and threaten the fragile ecosystem of the TP.

  12. Size-resolved source apportionment of ambient particles by positive matrix factorization at Gosan background site in East Asia

    NASA Astrophysics Data System (ADS)

    Han, J. S.; Moon, K. J.; Lee, S. J.; Kim, Y. J.; Ryu, S. Y.; Cliff, S. S.; Yi, S. M.

    2006-01-01

    Size- and time-resolved aerosol samples were collected using an eight-stage Davis rotating unit for monitoring (DRUM) sampler from 29 March to 29 May in 2002 at Gosan, Jeju Island, Korea, which is one of the representative background sites in East Asia. These samples were analyzed using synchrotron X-ray fluorescence for 3-h average concentrations of 19 elements consisting of S, Si, Al, Fe, Ca, Cl, Cu, Zn, Ti, K, Mn, Pb, Ni, V, Se, As, Rb, Cr, Br. The size-resolved data sets were then analyzed using the positive matrix factorization (PMF) technique in order to identify possible sources and estimate their contribution to particulate matter mass. PMF analysis uses the uncertainty of the measured data to provide an optimal weighting. Fifteen sources were resolved in eight size ranges (0.07~12 μm) and included continental soil, local soil, sea salt, biomass/biofuel burning, coal combustion, oil heating furnace, residual oil fired boiler, municipal incineration, nonferrous metal source, ferrous metal source, gasoline vehicle, diesel vehicle, copper smelter and volcanic emission. PMF analysis of size-resolved source contributions showed that natural sources represented by local soil, sea salt and continental soil contributed about 79% to the predicted primary particulate matter (PM) mass in the coarse size range (1.15~12 μm). On the other hand, anthropogenic sources such as coal combustion and biomass/biofuel burning contributed about 60% in the fine size range (0.56~2.5 μm). The diesel vehicle source contributed the most in the ultra-fine size range (0.07~0.56 μm) and was responsible for about 52% of the primary PM mass.

  13. Investigation of neutron-induced background in Magnetic-Recoil-Spectrometer CR-39 data using a DT neutron source and MCNP simulations

    NASA Astrophysics Data System (ADS)

    Milanese, Lucio M.; Frenje, Johan; Gatu Johnson, Maria; Lahmann, Brandon; Sio, Hong; Petrasso, Richard

    2015-11-01

    The Magnetic Recoil neutron Spectrometers (MRS) installed on the OMEGA laser facility and the National Ignition Facility (NIF) are routinely used to measure neutron yield, areal density and ion temperatures from DT implosions. The observed background in the lower-energy part of MRS spectra is significantly higher than expected from analysis of neutron-induced background data obtained in stand-alone CR-39 experiments at OMEGA. A possible explanation relates to the scattering of neutrons in the MRS housing vessel, which is not accounted for in current modeling. To test experimentally the impact of individual vessel components on the observed background, parts of the MRS housing have been mocked up and CR-39 data have been collected employing a DT neutron source. The experimental results are contrasted to MCNP simulations to improve our understanding of the mechanism behind the enhanced neutron background. The results will be used to correct measured spectra from OMEGA and the NIF to allow detailed analysis of lower energy data. This work was supported in part by NLUF, US DOE, and LLE.

  14. Background concentrations and source apportionment of polycyclic aromatic hydrocarbons in south-eastern Finland

    NASA Astrophysics Data System (ADS)

    Vestenius, Mika; Leppänen, Sirkka; Anttila, Pia; Kyllönen, Katriina; Hatakka, Juha; Hellén, Heidi; Hyvärinen, Antti-Pekka; Hakola, Hannele

    2011-07-01

    Polycyclic aromatic hydrocarbons (PAH compounds) were measured in the PM 10 fraction [from ambient air] at Virolahti, Finland. The sampling site is located in a rural area in the south-eastern corner of Finland, near the Russian border. Altogether, 51 daily and 85 weekly filter samples were collected in 2007-2008. The yearly average concentration of benzo(a)pyrene at Virolahti in 2007 was 0.21 ng m -3, which is well below the annual target value of 1 ng m -3 set by the European Union. The positive matrix factorization (PMF) method was applied in source apportionment for daily PAH data combined with other pollutant data. A three-factor solution of the PMF analysis with 28 components was chosen. These three factors were identified as long-range transported secondary particles (F1), combustion (F2) and a sea-salt factor (F3). The conditional probability function (CPF) was used to combine wind direction sectors with the PMF factors. In cases F1 and F2, pollutants mainly originated from the south-east, whereas pollutants in F3 came from the south-western sector. PAHs entered into the combustion factor 2 together with SO 2, NO x, black carbon and potassium. This suggests that the PAHs at Virolahti originated from traffic and industrial pollution, as well as biomass burning. Elevated concentrations occurred throughout the winter period and most frequently originated from the south-eastern sector between 90°-135°. This sector includes, among other transboundary areas, the metropolis of St. Petersburg at a distance of 160 km.

  15. Sources of machine-induced background in the ATLAS and CMS detectors at the CERN Large Hadron Collider

    SciTech Connect

    Bruce, R.; et al.,

    2013-11-21

    One source of experimental background in the CERN Large Hadron Collider (LHC) is particles entering the detectors from the machine. These particles are created in cascades, caused by upstream interactions of beam protons with residual gas molecules or collimators. We estimate the losses on the collimators with SixTrack and simulate the showers with FLUKA and MARS to obtain the flux and distribution of particles entering the ATLAS and CMS detectors. We consider some machine configurations used in the first LHC run, with focus on 3.5 TeV operation as in 2011. Results from FLUKA and MARS are compared and a very good agreement is found. An analysis of logged LHC data provides, for different processes, absolute beam loss rates, which are used together with further simulations of vacuum conditions to normalize the results to rates of particles entering the detectors. We assess the relative importance of background from elastic and inelastic beam-gas interactions, and the leakage out of the LHC collimation system, and show that beam-gas interactions are the dominating source of machine-induced background for the studied machine scenarios. Our results serve as a starting point for the experiments to perform further simulations in order to estimate the resulting signals in the detectors.

  16. Sources of machine-induced background in the ATLAS and CMS detectors at the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Bruce, R.; Assmann, R. W.; Boccone, V.; Bregliozzi, G.; Burkhardt, H.; Cerutti, F.; Ferrari, A.; Huhtinen, M.; Lechner, A.; Levinsen, Y.; Mereghetti, A.; Mokhov, N. V.; Tropin, I. S.; Vlachoudis, V.

    2013-11-01

    One source of experimental background in the CERN Large Hadron Collider (LHC) is particles entering the detectors from the machine. These particles are created in cascades, caused by upstream interactions of beam protons with residual gas molecules or collimators. We estimate the losses on the collimators with SixTrack and simulate the showers with FLUKA and MARS to obtain the flux and distribution of particles entering the ATLAS and CMS detectors. We consider some machine configurations used in the first LHC run, with focus on 3.5 TeV operation as in 2011. Results from FLUKA and MARS are compared and a very good agreement is found. An analysis of logged LHC data provides, for different processes, absolute beam loss rates, which are used together with further simulations of vacuum conditions to normalize the results to rates of particles entering the detectors. We assess the relative importance of background from elastic and inelastic beam-gas interactions, and the leakage out of the LHC collimation system, and show that beam-gas interactions are the dominating source of machine-induced background for the studied machine scenarios. Our results serve as a starting point for the experiments to perform further simulations in order to estimate the resulting signals in the detectors.

  17. [Characteristics of atmospheric CO2 concentration and variation of carbon source & sink at Lin'an regional background station].

    PubMed

    Pu, Jing-Jiao; Xu, Hong-Hui; Kang, Li-Li; Ma, Qian-Li

    2011-08-01

    Characteristics of Atmospheric CO2 concentration obtained by Flask measurements were analyzed at Lin'an regional background station from August 2006 to July 2009. According to the simulation results of carbon tracking model, the impact of carbon sources and sinks on CO2 concentration was evaluated in Yangtze River Delta. The results revealed that atmospheric CO2 concentrations at Lin'an regional background station were between 368.3 x 10(-6) and 414.8 x 10(-6). The CO2 concentration varied as seasons change, with maximum in winter and minimum in summer; the annual difference was about 20.5 x 10(-6). The long-term trend of CO2 concentration showed rapid growth year by year; the average growth rate was about 3.2 x 10(-6)/a. CO2 flux of Yangtze River Delta was mainly contributed by fossil fuel burning, terrestrial biosphere exchange and ocean exchange, while the contribution of fire emission was small. CO2 flux from fossil fuel burning played an important role in carbon source; terrestrial biosphere and ocean were important carbon sinks in this area. Seasonal variations of CO2 concentration at Lin'an regional background station were consistent with CO2 fluxes from fossil fuel burning and terrestrial biosphere exchange.

  18. Changes in background aerosol composition in Finland during polluted and clean periods studied by TEM/EDX individual particle analysis

    NASA Astrophysics Data System (ADS)

    Niemi, J. V.; Saarikoski, S.; Tervahattu, H.; Mäkelä, T.; Hillamo, R.; Vehkamäki, H.; Sogacheva, L.; Kulmala, M.

    2006-07-01

    Aerosol samples were collected at a rural background site in southern Finland in May 2004. The elemental composition, morphology and mixing state of individual aerosol particles in three size fractions were studied using transmission electron microscopy (TEM) coupled with energy dispersive X-ray (EDX) microanalyses. The TEM/EDX results were complemented with the size-segregated bulk chemical measurements of selected ions and organic and elemental carbon. Many of the particles in PM0.2-1 and PM1-3.3 size fractions were strongly internally mixed with S, C and/or N. The major particle types in all PM0.2-1 samples were ammonium sulphates with/without carbon and dark inclusion(s) (number proportion of particles 54-86%), carbon/sulphate mixture with dark inclusions(s) (4-10%), internally mixed soot/sulphate particles (2-22%), soot (0-12%) and K-rich particles with S and/or C (0-9%). During the pollution episode (PM1.6~18 μg m-3, the proportion of Ca-rich particles was very high (26-48%) in the PM1-3.3 and PM3.3-11 samples, while the PM0.2-1 and PM1-3.3 samples contained elevated proportions of silicates (22-33%, also fly ash particles), metal oxides/hydroxides (1-9%) and tar balls (1-4%). These aerosols originated mainly from polluted areas of Eastern Europe, and some open biomass burning smoke was also brought by long-range transport. During the clean period (PM1.6~2 μg m-3, when air masses arrived from the Arctic Ocean, PM1-3.3 samples contained mainly sea salt particles (67-89%) with a variable rate of Cl substitution (mainly by NO3-. During the intermediate period (PM1.6~5 μg m-3, the PM1-3.3 sample contained porous (sponge-like) Na-rich particles (35%) with abundant S, K and O. They might originate from the burning of wood pulp wastes of paper industry. The proportion of biological particles and C-rich fragments (probably also biological origin) were highest in the PM3.3-11 samples (0-81% and 0-22%, respectively). The origin of different particle types and the

  19. Changes in background aerosol composition in Finland during polluted and clean periods studied by TEM/EDX individual particle analysis

    NASA Astrophysics Data System (ADS)

    Niemi, J. V.; Saarikoski, S.; Tervahattu, H.; Mäkelä, T.; Hillamo, R.; Vehkamäki, H.; Sogacheva, L.; Kulmala, M.

    2006-11-01

    Aerosol samples were collected at a rural background site in southern Finland in May 2004 during pollution episode (PM1~16 µg m-3, backward air mass trajectories from south-east), intermediate period (PM1~5 µg m-3, backtrajectories from north-east) and clean period (PM1~2 µg m-3, backtrajectories from north-west/north). The elemental composition, morphology and mixing state of individual aerosol particles in three size fractions were studied using transmission electron microscopy (TEM) coupled with energy dispersive X-ray (EDX) microanalyses. The TEM/EDX results were complemented with the size-segregated bulk chemical measurements of selected ions and organic and elemental carbon. Many of the particles in PM0.2-1 and PM1-3.3 size fractions were strongly internally mixed with S, C and/or N. The major particle types in PM0.2-1 samples were 1) soot and 2) (ammonium)sulphates and their mixtures with variable amounts of C, K, soot and/or other inclusions. Number proportions of those two particle groups in PM0.2-1 samples were 0-12% and 83-97%, respectively. During the pollution episode, the proportion of Ca-rich particles was very high (26-48%) in the PM1-3.3 and PM3.3-11 samples, while the PM0.2-1 and PM1-3.3 samples contained elevated proportions of silicates (22-33%), metal oxides/hydroxides (1-9%) and tar balls (1-4%). These aerosols originated mainly from polluted areas of Eastern Europe, and some open biomass burning smoke was also brought by long-range transport. During the clean period, when air masses arrived from the Arctic Ocean, PM1-3.3 samples contained mainly sea salt particles (67-89%) with a variable rate of Cl substitution (mainly by NO3-). During the intermediate period, the PM1-3.3 sample contained porous (sponge-like) Na-rich particles (35%) with abundant S, K and O. They might originate from the burning of wood pulp wastes of paper industry. The proportion of biological particles and C-rich fragments (probably also biological origin) were highest

  20. Detecting black bear source-sink dynamics using individual-based genetic graphs.

    PubMed

    Draheim, Hope M; Moore, Jennifer A; Etter, Dwayne; Winterstein, Scott R; Scribner, Kim T

    2016-07-27

    Source-sink dynamics affects population connectivity, spatial genetic structure and population viability for many species. We introduce a novel approach that uses individual-based genetic graphs to identify source-sink areas within a continuously distributed population of black bears (Ursus americanus) in the northern lower peninsula (NLP) of Michigan, USA. Black bear harvest samples (n = 569, from 2002, 2006 and 2010) were genotyped at 12 microsatellite loci and locations were compared across years to identify areas of consistent occupancy over time. We compared graph metrics estimated for a genetic model with metrics from 10 ecological models to identify ecological factors that were associated with sources and sinks. We identified 62 source nodes, 16 of which represent important source areas (net flux > 0.7) and 79 sink nodes. Source strength was significantly correlated with bear local harvest density (a proxy for bear density) and habitat suitability. Additionally, resampling simulations showed our approach is robust to potential sampling bias from uneven sample dispersion. Findings demonstrate black bears in the NLP exhibit asymmetric gene flow, and individual-based genetic graphs can characterize source-sink dynamics in continuously distributed species in the absence of discrete habitat patches. Our findings warrant consideration of undetected source-sink dynamics and their implications on harvest management of game species.

  1. Self-reported information sources and perceived knowledge in individuals with lymphedema.

    PubMed

    Deng, J; Fu, M R; Armer, J M; Cormier, J N; Radina, E; Thiadens, S R J; Dietrich, M S; Weiss, J; Tuppo, C M; Ridner, S H

    2013-12-01

    Currently, a limited number of studies have been conducted that examine sources of information and knowledge level in individuals with lymphedema. This study aimed (1) to examine self-reported information sources and perceived lymphedema knowledge among individuals with lymphedema; and (2) to examine differences in self-reported information sources and perceived lymphedema knowledge among individuals with primary or secondary lymphedema; and with upper or lower extremity lymphedema. The National Lymphedema Network (NLN) conducted a survey to collect self-report data from March 2006 to January 2010. Overall, participants preferred a variety of sources of information. Participants reported low levels of knowledge about the types of lymphedema, treatment approaches and methods, and self-administrated therapies. In comparison to participants with secondary or upper extremity lymphedema, participants with primary or lower extremity lymphedema reported lower knowledge level regarding causes of lymphedema, risks for and complications of lymphedema, treatment approaches and methods for lymphedema, and self-administered therapies. Opportunities exist to expand lymphedema information sources. Healthcare professionals should focus on delivering high quality information about treatment and self-care management to individuals with lymphedema.

  2. Analysis of multi-source metabolomic data using joint and individual variation explained (JIVE).

    PubMed

    Kuligowski, Julia; Pérez-Guaita, David; Sánchez-Illana, Ángel; León-González, Zacarías; de la Guardia, Miguel; Vento, Máximo; Lock, Eric F; Quintás, Guillermo

    2015-07-07

    Metabolic profiling is increasingly being used for understanding biological processes but there is no single analytical technique that provides a complete quantitative or qualitative profiling of the metabolome. Data fusion (i.e. joint analysis of data from multiple sources) has the potential to circumvent this issue facilitating knowledge discovery and reliable biomarker identification. Another field of application of data fusion is the simultaneous analysis of metabolomic changes through several biofluids or tissues. However, metabolomics typically deals with large datasets, with hundreds to thousands of variables and the identification of shared and individual factors or structures across multiple sources is challenging due to the high variable to sample ratios and differences in intensity and noise range. In this work we apply a recent method, Joint and Individual Variation Explained (JIVE), for the integrated unsupervised analysis of metabolomic profiles from multiple data sources. This method separates the shared patterns among data sources (i.e. the joint structure) from the individual structure of each data source that is unrelated to the joint structure. Two examples are described to show the applicability of JIVE for the simultaneous analysis of multi-source data using: (i) plasma samples subjected to different analytical techniques, sample treatment and measurement conditions; and (ii) plasma and urine samples subjected to liquid chromatography-mass spectrometry measured using two ionization conditions.

  3. Simulating variable source problems via post processing of individual particle tallies

    SciTech Connect

    Bleuel, D.L.; Donahue, R.J.; Ludewigt, B.A.; Vujic, J.

    2000-10-20

    Monte Carlo is an extremely powerful method of simulating complex, three dimensional environments without excessive problem simplification. However, it is often time consuming to simulate models in which the source can be highly varied. Similarly difficult are optimization studies involving sources in which many input parameters are variable, such as particle energy, angle, and spatial distribution. Such studies are often approached using brute force methods or intelligent guesswork. One field in which these problems are often encountered is accelerator-driven Boron Neutron Capture Therapy (BNCT) for the treatment of cancers. Solving the reverse problem of determining the best neutron source for optimal BNCT treatment can be accomplished by separating the time-consuming particle-tracking process of a full Monte Carlo simulation from the calculation of the source weighting factors which is typically performed at the beginning of a Monte Carlo simulation. By post-processing these weighting factors on a recorded file of individual particle tally information, the effect of changing source variables can be realized in a matter of seconds, instead of requiring hours or days for additional complete simulations. By intelligent source biasing, any number of different source distributions can be calculated quickly from a single Monte Carlo simulation. The source description can be treated as variable and the effect of changing multiple interdependent source variables on the problem's solution can be determined. Though the focus of this study is on BNCT applications, this procedure may be applicable to any problem that involves a variable source.

  4. Expert and crowd-sourced validation of an individualized sleep spindle detection method employing complex demodulation and individualized normalization.

    PubMed

    Ray, Laura B; Sockeel, Stéphane; Soon, Melissa; Bore, Arnaud; Myhr, Ayako; Stojanoski, Bobby; Cusack, Rhodri; Owen, Adrian M; Doyon, Julien; Fogel, Stuart M

    2015-01-01

    A spindle detection method was developed that: (1) extracts the signal of interest (i.e., spindle-related phasic changes in sigma) relative to ongoing "background" sigma activity using complex demodulation, (2) accounts for variations of spindle characteristics across the night, scalp derivations and between individuals, and (3) employs a minimum number of sometimes arbitrary, user-defined parameters. Complex demodulation was used to extract instantaneous power in the spindle band. To account for intra- and inter-individual differences, the signal was z-score transformed using a 60 s sliding window, per channel, over the course of the recording. Spindle events were detected with a z-score threshold corresponding to a low probability (e.g., 99th percentile). Spindle characteristics, such as amplitude, duration and oscillatory frequency, were derived for each individual spindle following detection, which permits spindles to be subsequently and flexibly categorized as slow or fast spindles from a single detection pass. Spindles were automatically detected in 15 young healthy subjects. Two experts manually identified spindles from C3 during Stage 2 sleep, from each recording; one employing conventional guidelines, and the other, identifying spindles with the aid of a sigma (11-16 Hz) filtered channel. These spindles were then compared between raters and to the automated detection to identify the presence of true positives, true negatives, false positives and false negatives. This method of automated spindle detection resolves or avoids many of the limitations that complicate automated spindle detection, and performs well compared to a group of non-experts, and importantly, has good external validity with respect to the extant literature in terms of the characteristics of automatically detected spindles.

  5. Source contributions to PM2.5 and PM10 at an urban background and a street location

    NASA Astrophysics Data System (ADS)

    Keuken, M. P.; Moerman, M.; Voogt, M.; Blom, M.; Weijers, E. P.; Röckmann, T.; Dusek, U.

    2013-06-01

    The contribution of regional, urban and traffic sources to PM2.5 and PM10 in an urban area was investigated in this study. The chemical composition of PM2.5 and PM10 was measured over a year at a street location and up- and down-wind of the city of Rotterdam, the Netherlands. The 14C content in EC and OC concentrations was also determined, to distinguish the contribution from "modern" carbon (e.g., biogenic emissions, biomass burning and wildfires) and fossil fuel combustion. It was concluded that the urban background of PM2.5 and PM10 is dominated by the regional background, and that primary and secondary PM emission by urban sources contribute less than 15%. The 14C analysis revealed that 70% of OC originates from modern carbon and 30% from fossil fuel combustion. The corresponding percentages for EC are, respectively 17% and 83%. It is concluded that in particular the urban population living in street canyons with intense road traffic has potential health risks. This is due to exposure to elevated concentrations of a factor two for EC from exhaust emissions in PM2.5 and a factor 2-3 for heavy metals from brake and tyre wear, and re-suspended road dust in PM10. It follows that local air quality management may focus on local measures to street canyons with intense road traffic.

  6. Probing Large-scale Coherence between Spitzer IR and Chandra X-Ray Source-subtracted Cosmic Backgrounds

    NASA Astrophysics Data System (ADS)

    Cappelluti, N.; Arendt, R.; Kashlinsky, A.; Li, Y.; Hasinger, G.; Helgason, K.; Urry, M.; Natarajan, P.; Finoguenov, A.

    2017-09-01

    We present new measurements of the large-scale clustering component of the cross-power spectra of the source-subtracted Spitzer-IRAC cosmic infrared background and Chandra-ACIS cosmic X-ray background surface brightness fluctuations Our investigation uses data from the Chandra Deep Field South, Hubble Deep Field North, Extended Groth Strip/AEGIS field, and UDS/SXDF surveys, comprising 1160 Spitzer hours and ∼12 Ms of Chandra data collected over a total area of 0.3 deg2. We report the first (>5σ) detection of a cross-power signal on large angular scales >20″ between [0.5–2] keV and the 3.6 and 4.5 μm bands, at ∼5σ and 6.3σ significance, respectively. The correlation with harder X-ray bands is marginally significant. Comparing the new observations with existing models for the contribution of the known unmasked source population at z < 7, we find an excess of about an order of magnitude at 5σ confidence. We discuss possible interpretations for the origin of this excess in terms of the contribution from accreting early black holes (BHs), including both direct collapse BHs and primordial BHs, as well as from scattering in the interstellar medium and intra-halo light.

  7. Radiation Optimized Dual-source Dual-energy Computed Tomography Pulmonary Angiography: Intra-individual and Inter-individual Comparison.

    PubMed

    Li, Xie; Chen, Guo Zhong; Zhao, Yan E; Schoepf, U Joseph; Albrecht, Moritz H; Bickford, Matthew W; Gu, Hai Feng; Zhang, Long Jiang; Lu, Guang Ming

    2017-01-01

    This study aimed to intra-individually and inter-individually compare image quality, radiation dose, and diagnostic accuracy of dual-source dual-energy computed tomography pulmonary angiography (CTPA) protocols in patients with suspected pulmonary embolism (PE). Thirty-three patients with suspected PE underwent initial and follow-up dual-energy CTPA at 80/Sn140 kVp (group A) or 100/Sn140 kVp (group B), which were assigned based on tube voltages. Subjective and objective CTPA image quality and lung perfusion map image quality were evaluated. Diagnostic accuracies of CTPA and perfusion maps were assessed by two radiologists independently. Effective dose (ED) was calculated and compared. Mean computed tomography (CT) values of pulmonary arteries were higher in group A than group B (P = .006). There was no difference in signal-to-noise ratio and contrast-to-noise ratio between the two groups (both P > .05). Interobserver agreement for evaluating subjective image quality of CTPA and color-coded perfusion images was either good (κ = 0.784) or excellent (κ = 0.887). Perfusion defect scores and diagnostic accuracy of CTPA showed no difference between both groups (both P > .05). Effective dose of group A was reduced by 45.8% compared to group B (P < .001). Second-generation dual-source dual-energy CTPA with 80/Sn140 kVp allows for sufficient image quality and diagnostic accuracy for detecting PE while substantially reducing radiation dose. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  8. Project TIES: Tracing Individual Ethnic Sources. Activities, Grades 10-12.

    ERIC Educational Resources Information Center

    Allegheny Intermediate Unit, Pittsburgh, PA.

    Tracing Individual Ethnic Sources (Project TIES) offers students a chance to explore the area of ethnicity by first examining their own family and cultural heritage and then comparing their history to that of others in the hope of reinforcing the universality of culture, promoting the acceptance of ethnic diversity, and restraining cultural…

  9. Spectro-refractometry of individual microscopic objects using swept-source quantitative phase imaging.

    PubMed

    Jung, Jae-Hwang; Jang, Jaeduck; Park, Yongkeun

    2013-11-05

    We present a novel spectroscopic quantitative phase imaging technique with a wavelength swept-source, referred to as swept-source diffraction phase microscopy (ssDPM), for quantifying the optical dispersion of microscopic individual samples. Employing the swept-source and the principle of common-path interferometry, ssDPM measures the multispectral full-field quantitative phase imaging and spectroscopic microrefractometry of transparent microscopic samples in the visible spectrum with a wavelength range of 450-750 nm and a spectral resolution of less than 8 nm. With unprecedented precision and sensitivity, we demonstrate the quantitative spectroscopic microrefractometry of individual polystyrene beads, 30% bovine serum albumin solution, and healthy human red blood cells.

  10. [Evaluation on the Impacts of Different Background Determination Methods on CO2 Sources and Sinks Estimation and Seasonal Variations].

    PubMed

    Zhang, Fang; Zhou, Ling-xi; Wang, Yu-zhao

    2015-07-01

    To accurately determine background conditions or extract sources and sinks information from the observed atmospheric carbon dioxide (CO2) concentration is crucial for quantitative estimation of regional and global carbon budget and future trends of atmospheric CO2. In this study, the synchronized observed surface winds and carbon monoxide (CO) concentration have been examined to test their effectiveness as filter factors to determine CO2 background conditions at Waliguan site. The results show that the surface winds and CO concentrations can be used as filter factor in winter, but they are not very effective in summer. Three statistical methods, robust estimation of background signal (REBS), Fourier transform algorithm (FTA) and a new developed moving average filtering (MAF), are applied to atmospheric CO2 background selection. The result suggested that our new developed MAF method, which can well estimate the elevated and sequestered CO2 concentrations due to using changing and adjusting filter criteria at every two-week fitting window, is thus better than the other two statistical methods. A good consistency is indicated by the three methods for estimating the elevated CO2 caused by local or regional emissions, but it showed large discrepancies when determining the sequestered CO2. The result suggested that the three methods can reasonable extract those anthropogenic influenced episodes, but only MAF method would well identify those episodes due to terrestrial CO2 fluxes. Mean seasonal amplitude of atmospheric CO2 at Waliguan during 1995-2008 is 10. 3 x 10(-6) estimated by MAF method, which is in good agreement with previous studies. Whereas, the seasonal amplitudes derived by REBS method are much lower, only with a value of ~9. 1 x 10(-6) during 1995-2008, which will result in an underestimation of regional or global CO2 fluxes.

  11. Source Apportionment of Background PAHs in the Peace-Athabasca Delta (Alberta, Canada) Using Molecular Level Radiocarbon Analysis.

    PubMed

    Jautzy, Josué J; Ahad, Jason M E; Hall, Roland I; Wiklund, Johan A; Wolfe, Brent B; Gobeil, Charles; Savard, Martine M

    2015-08-04

    The downstream accumulation of polycyclic aromatic hydrocarbons (PAHs) in the Peace-Athabasca Delta (PAD), an ecologically important landscape, is a key issue of concern given the rapid development of the oil sands industry in Northern Alberta, Canada. In addition to PAHs derived from industrial activity (i.e., oil sands mining) within the Athabasca watershed, however, forest fires and erosion of fossil fuel deposits within both the Athabasca and Peace watersheds are two potentially important natural sources of PAHs delivered to the PAD. Consequently, evaluating the environmental impact of mining activities requires a quantitative understanding of natural, background PAHs. Here, we utilize molecular-level natural-abundance radiocarbon measurements on an amalgamated sediment record from a Peace River flood-susceptible oxbow lake in the northern Peace sector of the PAD to quantitatively discriminate sources of naturally occurring alkylated PAHs (fossil and modern biomass). A radiocarbon mass balance quantified a predominantly natural petrogenic source (93% petrogenic, 7% forest fire) for alkylated PAHs during the past ∼50 years. Additionally, a significant petrogenic component determined for retene, a compound usually considered a biomarker for softwood combustion, suggests that its use as a unique forest fire indicator may not be suitable in PAD sediments receiving Peace watershed-derived fluvial inputs.

  12. PM10 concentration levels at an urban and background site in Cyprus: the impact of urban sources and dust storms.

    PubMed

    Achilleos, Souzana; Evans, John S; Yiallouros, Panayiotis K; Kleanthous, Savvas; Schwartz, Joel; Koutrakis, Petros

    2014-12-01

    Air quality in Cyprus is influenced by both local and transported pollution, including desert dust storms. We examined PM10 concentration data collected in Nicosia (urban representative) from April 1, 1993, through December 11, 2008, and in Ayia Marina (rural background representative) from January 1, 1999, through December 31, 2008. Measurements were conducted using a Tapered Element Oscillating Micro-balance (TEOM). PM10 concentrations, meteorological records, and satellite data were used to identify dust storm days. We investigated long-term trends using a Generalized Additive Model (GAM) after controlling for day of week, month, temperature, wind speed, and relative humidity. In Nicosia, annual PM10 concentrations ranged from 50.4 to 63.8 μg/m3 and exceeded the EU annual standard limit enacted in 2005 of 40 μg/m3 every year A large, statistically significant impact of urban sources (defined as the difference between urban and background levels) was seen in Nicosia over the period 2000-2008, and was highest during traffic hours, weekdays, cold months, and low wind conditions. Our estimate of the mean (standard error) contribution of urban sources to the daily ambient PM10 was 24.0 (0.4) μg/m3. The study of yearly trends showed that PM10 levels in Nicosia decreased from 59.4 μg/m3 in 1993 to 49.0 μg/m3 in 2008, probably in part as a result of traffic emission control policies in Cyprus. In Ayia Marina, annual concentrations ranged from 27.3 to 35.6 μg/m3, and no obvious time trends were observed. The levels measured at the Cyprus background site are comparable to background concentrations reported in other Eastern Mediterranean countries. Average daily PM10 concentrations during desert dust storms were around 100 μg/m3 since 2000 and much higher in earlier years. Despite the large impact ofdust storms and their increasing frequency over time, dust storms were responsible for a small fraction of the exceedances of the daily PM10 limit. Implications: This

  13. PM10 Concentration levels at an urban and background site in Cyprus: The impact of urban sources and dust storms

    PubMed Central

    Achilleos, Souzana; Evans, John S.; Yiallouros, Panayiotis K.; Kleanthous, Savvas; Schwartz, Joel; Koutrakis, Petros

    2016-01-01

    Air quality in Cyprus is influenced by both local and transported pollution including desert dust storms. We examined PM10 concentration data collected in Nicosia (urban representative) from April 1, 1993 through December 11, 2008, and Ayia Marina (rural background representative) from January 1, 1999 through December 31, 2008. Measurements were conducted using a Tapered Element Oscillating Micro-balance (TEOM). PM10 concentrations, meteorological records and satellite data were used to identify dust storm days. We investigated long term trends using a Generalized Additive Model (GAM) after controlling for day of week, month, temperature, wind speed, and relative humidity. In Nicosia, annual PM10 concentrations ranged from 50.4 to 63.8 μg/m3 and exceeded the EU annual standard limit enacted in 2005 of 40 μg/m3 every year. A large, statistically significant impact of urban sources (defined as the difference between urban and background levels) was seen in Nicosia over the period 2000–2008, and was highest during traffic hours, weekdays, cold months, and low wind conditions. Our estimate of the mean (standard error) contribution of urban sources to the daily ambient PM10 was 24.0 (0.4) μg/m3. The study of yearly trends showed that PM10 levels in Nicosia decreased from 59.4 μg/m3 in 1993 to 49.0 μg/m3 in 2008, probably in part as a result of traffic emission control policies in Cyprus. In Ayia Marina, annual concentrations ranged from 27.3 to 35.6 μg/m3, and no obvious time trends were observed. The levels measured at the Cyprus background site are comparable to background concentrations reported in other Eastern Mediterranean countries. Average daily PM10 concentrations during desert dust storms were around 100 μg/m3 since 2000 and much higher in earlier years. Despite the large impact of dust storms and their increasing frequency over time, dust storms were responsible for a small fraction of the exceedances of the daily PM10 limit. PMID:25562931

  14. A Survey of Information Source Preferences of Parents of Individuals with Autism Spectrum Disorder.

    PubMed

    Gibson, Amelia N; Kaplan, Samantha; Vardell, Emily

    2017-07-01

    For parents of children with an Autism spectrum disorder (ASD), high quality, easily accessible information and a strong peer network can be the key to raising a happy, healthy child, and maintaining family well-being and emotional resilience. This article reports the findings of an anonymous survey examining the information source preferences for 935 parents of individuals with ASDs in North Carolina. Data indicates that parents show similar information seeking patterns across the age spectrum, that availability of information (as indicated by overall information source selection) decrease as children age. It also shows that parents rely heavily on local sources of information, preferring them to nonlocal sources (such as the internet) for many types of information.

  15. The impact of individual materials parameters on color temperature reproducibility among phosphor converted LED sources

    NASA Astrophysics Data System (ADS)

    Schweitzer, Susanne; Nemitz, Wolfgang; Sommer, Christian; Hartmann, Paul; Fulmek, Paul; Nicolics, Johann; Pachler, Peter; Hoschopf, Hans; Schrank, Franz; Langer, Gregor; Wenzl, Franz P.

    2014-09-01

    For a systematic approach to improve the white light quality of phosphor converted light-emitting diodes (LEDs) for general lighting applications it is imperative to get the individual sources of error for color temperature reproducibility under control. In this regard, it is imperative to understand how compositional, optical and materials properties of the color conversion element (CCE), which typically consists of phosphor particles embedded in a transparent matrix material, affect the constancy of a desired color temperature of a white LED source. In this contribution we use an LED assembly consisting of an LED die mounted on a printed circuit board (PCB) by chip-on-board technology and a CCE with a glob-top configuration as a model system and discuss the impact of potential sources for color temperature deviation among individual devices. Parameters that are investigated include imprecisions in the amount of materials deposition, deviations from the target value for the phosphor concentration in the matrix material, deviations from the target value for the particle sizes of the phosphor material, deviations from the target values for the refractive indexes of phosphor and matrix material as well as deviations from the reflectivity of the substrate surface. From these studies, some general conclusions can be drawn which of these parameters have the largest impact on color deviation and have to be controlled most precisely in a fabrication process in regard of color temperature reproducibility among individual white LED sources.

  16. Personal Best (PB) Goal Structure, Individual PB Goals, Engagement, and Achievement: A Study of Chinese- and English-Speaking Background Students in Australian Schools

    ERIC Educational Resources Information Center

    Martin, Andrew J.; Collie, Rebecca J.; Mok, Magdalena M. C.; McInerney, Dennis M.

    2016-01-01

    Background: Prior cross-cultural research with students in different national contexts (Australia and China) has shown consistency in the extent to which individual personal best (PB) goals are associated with engagement at school. Aims: This study extends this work to a multicultural context, assessing perceived PB goal structure in school and…

  17. Personal Best (PB) Goal Structure, Individual PB Goals, Engagement, and Achievement: A Study of Chinese- and English-Speaking Background Students in Australian Schools

    ERIC Educational Resources Information Center

    Martin, Andrew J.; Collie, Rebecca J.; Mok, Magdalena M. C.; McInerney, Dennis M.

    2016-01-01

    Background: Prior cross-cultural research with students in different national contexts (Australia and China) has shown consistency in the extent to which individual personal best (PB) goals are associated with engagement at school. Aims: This study extends this work to a multicultural context, assessing perceived PB goal structure in school and…

  18. EXPOSURE VERSION 2 - A COMPUTER MODEL FOR ANALYZING THE EFFECTS OF INDOOR AIR POLLUTANT SOURCES ON INDIVIDUAL EXPOSURE

    EPA Science Inventory

    The report presents a model for calculating individual exposure to indoor pollutants from sources. The model calculates exposure due to individual, as opposed to population, activity patterns and source use. The model uses data on source emissions, room- to- room air flows, air e...

  19. Contribution from individual nearby sources to the spectrum of high-energy cosmic-ray electrons

    NASA Astrophysics Data System (ADS)

    Sedrati, R.; Attallah, R.

    2014-04-01

    In the last few years, very important data on high-energy cosmic-ray electrons and positrons from high-precision space-born and ground-based experiments have attracted a great deal of interest. These particles represent a unique probe for studying local comic-ray accelerators because they lose energy very rapidly. These energy losses reduce the lifetime so drastically that high-energy cosmic-ray electrons can attain the Earth only from rather local astrophysical sources. This work aims at calculating, by means of Monte Carlo simulation, the contribution from some known nearby astrophysical sources to the cosmic-ray electron/positron spectra at high energy (≥ 10 GeV). The background to the electron energy spectrum from distant sources is determined with the help of the GALPROP code. The obtained numerical results are compared with a set of experimental data.

  20. An Updated Calibration of the ROSAT PSPC Particle Background for the Analysis of Diffuse and Extended Sources

    NASA Astrophysics Data System (ADS)

    Plucinsky, P. P.; Snowden, S. L.; Briel, U. G.; Hasinger, G.; Pfeffermann, E.

    1993-11-01

    In order to permit quantitative studies of the cosmic diffuse X-ray background (DXRB) and of extended X-ray sources, we present updated calibrations of the particle-induced background of the Position Sensitive Proportional Counters (PSPCs) on board the Röntgen Satellite (ROSAT). We present new parameterizations of the temporal, spectral, and spatial distributions of the particle-induced events following closely the analysis discussed in Snowden et al. (1992). The ROSAT Guest Observer (GO) may find a step-by-step method for applying these parameterizations to a GO observation in § 3.4. Except for a variable contamination which is present in channels ≤ 18 and a change in our understanding of the externally produced components, the current parameterizations are quite similar to the previous results. We have used the spectral information available on the variable contamination to formulate a method for determining the level of this contamination in a given observation. The PSPC rejection efficiency for particle background events in the pulse-height range 18 ≤ CH ≤ 249 is 99.90%, with a typical count rate of 4 × 10-6 counts s-1 arcmin-2 keV-1. During typical conditions, the count rate of residual events is well correlated with the Master Veto count rate. The spectrum in the pulse-height range 18 ≤ CH ≤ 249 is well described by a power law, a flat component, and an Al Kα line at 1.5 keV. The spatial distribution of counts with pulse heights ≥ 18 is uniform over the field of view except for a small radial gradient and shadowing of the Al Kα line and part of the flat continuum by the window support structure. During an astronomical observation in low-gain mode (after 1991 October 11), the particle background can also be monitored by the count rate in channels 260 ≤ CH ≤ 370, since in most cases all these events are produced by particles. We have used a 54 ks observation of the Ursa Major region to verify the accuracy of our model. We have also

  1. Improved dark energy detection through the polarization-assisted cross correlation of the cosmic microwave background with radio sources

    SciTech Connect

    Liu, Guo-Chin; Ng, Kin-Wang; Pen, Ue-Li

    2011-03-15

    Integrated Sachs-Wolfe (ISW) effect can be estimated by cross-correlating the cosmic microwave background (CMB) sky with tracers of the local matter distribution. At late cosmic time, the dark energy-induced decay of gravitation potential generates a cross correlation signal on large angular scales. The dominant noise is the intrinsic CMB anisotropies from the inflationary epoch. In this paper we use CMB polarization to reduce this intrinsic noise. We cross-correlate the microwave sky observed by Wilkinson Microwave Anisotropy Probe (WMAP) with the radio source catalog compiled by NRAO VLA Sky Survey (NVSS) to study the efficiency of the noise suppression. We find that the error bars are reduced by about 4 to 14% and the statistical power in the signal is improved.

  2. Vocal individuality cues in the African penguin (Spheniscus demersus): a source-filter theory approach.

    PubMed

    Favaro, Livio; Gamba, Marco; Alfieri, Chiara; Pessani, Daniela; McElligott, Alan G

    2015-11-25

    The African penguin is a nesting seabird endemic to southern Africa. In penguins of the genus Spheniscus vocalisations are important for social recognition. However, it is not clear which acoustic features of calls can encode individual identity information. We recorded contact calls and ecstatic display songs of 12 adult birds from a captive colony. For each vocalisation, we measured 31 spectral and temporal acoustic parameters related to both source and filter components of calls. For each parameter, we calculated the Potential of Individual Coding (PIC). The acoustic parameters showing PIC ≥ 1.1 were used to perform a stepwise cross-validated discriminant function analysis (DFA). The DFA correctly classified 66.1% of the contact calls and 62.5% of display songs to the correct individual. The DFA also resulted in the further selection of 10 acoustic features for contact calls and 9 for display songs that were important for vocal individuality. Our results suggest that studying the anatomical constraints that influence nesting penguin vocalisations from a source-filter perspective, can lead to a much better understanding of the acoustic cues of individuality contained in their calls. This approach could be further extended to study and understand vocal communication in other bird species.

  3. Vocal individuality cues in the African penguin (Spheniscus demersus): a source-filter theory approach

    PubMed Central

    Favaro, Livio; Gamba, Marco; Alfieri, Chiara; Pessani, Daniela; McElligott, Alan G.

    2015-01-01

    The African penguin is a nesting seabird endemic to southern Africa. In penguins of the genus Spheniscus vocalisations are important for social recognition. However, it is not clear which acoustic features of calls can encode individual identity information. We recorded contact calls and ecstatic display songs of 12 adult birds from a captive colony. For each vocalisation, we measured 31 spectral and temporal acoustic parameters related to both source and filter components of calls. For each parameter, we calculated the Potential of Individual Coding (PIC). The acoustic parameters showing PIC ≥ 1.1 were used to perform a stepwise cross-validated discriminant function analysis (DFA). The DFA correctly classified 66.1% of the contact calls and 62.5% of display songs to the correct individual. The DFA also resulted in the further selection of 10 acoustic features for contact calls and 9 for display songs that were important for vocal individuality. Our results suggest that studying the anatomical constraints that influence nesting penguin vocalisations from a source-filter perspective, can lead to a much better understanding of the acoustic cues of individuality contained in their calls. This approach could be further extended to study and understand vocal communication in other bird species. PMID:26602001

  4. Carbon Isotopes of Methane in the Atlantic Realm: Links Between Background Station Data and Emission Source Regions

    NASA Astrophysics Data System (ADS)

    Lowry, D.; Fisher, R. E.; Lanoisellé, M.; Nisbet, E. G.

    2011-12-01

    Large networks of cavity ring-down spectroscopy (CRDS) instruments to measure mixing ratios of greenhouse gases are currently being developed in wealthier populated regions. However, many major natural source regions are remote from wealthy nations, and there are often great logistical obstacles to setting up and maintaining continuous monitoring of these sources. Thus flux assessments in many regions of the world rely on a few unequally spaced 'background' stations, plus satellite interpolation. This limited network can be supplemented to great effect by methane isotope data to identify emissions from different sources and their region of emission. Ideally both carbon and hydrogen isotope signatures are needed for maximum separation of source groups. However the more complex analytical procedure and larger sample requirements for D/H measurement mean that resources are currently better utilized for high-precision carbon isotope (δ13C) measurement of methane. In particular, NOAA maintains an invaluable isotopic measurement network. Since 2008 the greenhouse gas group at Royal Holloway and partners have been measuring methane in and around the Atlantic region, currently measuring mixing ratios by CRDS at Barra (Scotland), Ascension, and E. Falklands. In addition, regular flask sampling for δ13C of CH4 is underway at these sites, plus Cape Point, South Africa, and Ny-Alesund, Spitzbergen, supplemented by collection at Sable Island, Canada, and sampling campaigns on-board the British Antarctic Survey ship, RRS James Clark Ross, between 50°S and 80°N. Methane mixing ratio and δ13C, when combined with back trajectory analysis, help to identify sources over which the air masses have passed. While the South Atlantic shows little N-S variation in δ13C (predominantly -47.2 to -46.8%) it is punctuated by emission plumes from sources in South America and Africa, and although infrequently sampled, they can in some instances be compared with the isotopic characteristics

  5. Ambient air benzene at background sites in China's most developed coastal regions: exposure levels, source implications and health risks.

    PubMed

    Zhang, Zhou; Wang, Xinming; Zhang, Yanli; Lü, Sujun; Huang, Zhonghui; Huang, Xinyu; Wang, Yuesi

    2015-04-01

    Benzene is a known human carcinogen causing leukemia, yet ambient air quality objectives for benzene are not available in China. The ambient benzene levels at four background sites in China's most developed coastal regions were measured from March 2012 to February 2013. The sites are: SYNECP, in the Northeast China Plain (NECP); YCNCP, in the North China Plain (NCP); THYRD, in the Yangtze River Delta (YRD) and DHPRD, in the Pearl River Delta (PRD). It was found that the mean annual benzene levels (578-1297 ppt) at the background sites were alarmingly higher, especially when compared to those of 60-480 pptv monitored in 28 cities in the United States. Wintertime benzene levels were significantly elevated at both sites (SYNECP and YCNCP) in northern China due to heating with coal/biofuels. Even at these background sites, the lifetime cancer risks of benzene (1.7-3.7E-05) all exceeded 1E-06 set by USEPA as acceptable for adults. At both sites in northern China, good correlations between benzene and CO or chloromethane, together with much lower toluene/benzene (T/B) ratios, suggested that benzene was largely related to coal combustion and biomass/biofuel burning. At the DHPRD site in the PRD, benzene revealed a highly significant correlation with methyl tert-butyl ether (MTBE), indicating that its source was predominantly from vehicle emissions. At the THYRD site in the YRD, higher T/B ratios and correlations between benzene and tetrachloroethylene, or MTBE, implied that benzene levels were probably affected by both traffic-related and industrial emissions.

  6. Probing Individual Sources during Reionization and Cosmic Dawn using Square Kilometre Array HI 21-cm Observations

    NASA Astrophysics Data System (ADS)

    Datta, Kanan K.; Ghara, Raghunath; Majumdar, Suman; Choudhury, T. Roy; Bharadwaj, Somnath; Roy, Himadri; Datta, Abhirup

    2016-12-01

    Detection of individual luminous sources during the reionization epoch and cosmic dawn through their signatures in the HI 21-cm signal is one of the direct approaches to probe the epoch. Here, we summarize our previous works on this and present preliminary results on the prospects of detecting such sources using the SKA1-low experiment. We first discuss the expected HI 21-cm signal around luminous sources at different stages of reionization and cosmic dawn. We then introduce two visibility based estimators for detecting such signals: one based on the matched filtering technique and the other relies on simply combing the visibility signal from different baselines and frequency channels. We find that the SKA1-low should be able to detect ionized bubbles of radius Rb ≳ 10 Mpc with ˜100 h of observations at redshift z˜8 provided that the mean outside neutral hydrogen fraction x_{ {HI}} ≳ 0.5. We also investigate the possibility of detecting HII regions around known bright QSOs such as around ULASJ1120+0641 discovered by Mortlock et al. ( Nature 474, 7353 (2011)). We find that a 5 σ detection is possible with 600 h of SKA1-low observations if the QSO age and the outside xHI are at least ˜2×107 Myr and ˜0.2 respectively. Finally, we investigate the possibility of detecting the very first X-ray and Ly- α sources during the cosmic dawn. We consider mini-QSOs like sources which emits in X-ray frequency band. We find that with a total ˜ 1000 h of observations, SKA1-low should be able to detect those sources individually with a ˜ 9 σ significance at redshift z=15. We summarize how the SNR changes with various parameters related to the source properties.

  7. 2010 August 1-2 Sympathetic Eruptions. I. Magnetic Topology of the Source-surface Background Field

    NASA Astrophysics Data System (ADS)

    Titov, V. S.; Mikic, Z.; Török, T.; Linker, J. A.; Panasenco, O.

    2012-11-01

    A sequence of apparently coupled eruptions was observed on 2010 August 1-2 by Solar Dynamics Observatory and STEREO. The eruptions were closely synchronized with one another, even though some of them occurred at widely separated locations. In an attempt to identify a plausible reason for such synchronization, we study the large-scale structure of the background magnetic configuration. The coronal field was computed from the photospheric magnetic field observed at the appropriate time period by using the potential field source-surface model. We investigate the resulting field structure by analyzing the so-called squashing factor calculated at the photospheric and source-surface boundaries, as well as at different coronal cross-sections. Using this information as a guide, we determine the underlying structural skeleton of the configuration, including separatrix and quasi-separatrix surfaces. Our analysis reveals, in particular, several pseudo-streamers in the regions where the eruptions occurred. Of special interest to us are the magnetic null points and separators associated with the pseudo-streamers. We propose that magnetic reconnection triggered along these separators by the first eruption likely played a key role in establishing the assumed link between the sequential eruptions. The present work substantiates our recent simplified magnetohydrodynamic model of sympathetic eruptions and provides a guide for further deeper study of these phenomena. Several important implications of our results for the S-web model of the slow solar wind are also addressed.

  8. 2010 AUGUST 1-2 SYMPATHETIC ERUPTIONS. I. MAGNETIC TOPOLOGY OF THE SOURCE-SURFACE BACKGROUND FIELD

    SciTech Connect

    Titov, V. S.; Mikic, Z.; Toeroek, T.; Linker, J. A.; Panasenco, O.

    2012-11-01

    A sequence of apparently coupled eruptions was observed on 2010 August 1-2 by Solar Dynamics Observatory and STEREO. The eruptions were closely synchronized with one another, even though some of them occurred at widely separated locations. In an attempt to identify a plausible reason for such synchronization, we study the large-scale structure of the background magnetic configuration. The coronal field was computed from the photospheric magnetic field observed at the appropriate time period by using the potential field source-surface model. We investigate the resulting field structure by analyzing the so-called squashing factor calculated at the photospheric and source-surface boundaries, as well as at different coronal cross-sections. Using this information as a guide, we determine the underlying structural skeleton of the configuration, including separatrix and quasi-separatrix surfaces. Our analysis reveals, in particular, several pseudo-streamers in the regions where the eruptions occurred. Of special interest to us are the magnetic null points and separators associated with the pseudo-streamers. We propose that magnetic reconnection triggered along these separators by the first eruption likely played a key role in establishing the assumed link between the sequential eruptions. The present work substantiates our recent simplified magnetohydrodynamic model of sympathetic eruptions and provides a guide for further deeper study of these phenomena. Several important implications of our results for the S-web model of the slow solar wind are also addressed.

  9. Source regions and transport pathways of PM2.5 at a regional background site in East China

    NASA Astrophysics Data System (ADS)

    Zhang, Yanru; Zhang, Hongliang; Deng, Junjun; Du, Wenjiao; Hong, Youwei; Xu, Lingling; Qiu, Yuqing; Hong, Zhenyu; Wu, Xin; Ma, Qianli; Yao, Jie; Chen, Jinsheng

    2017-10-01

    PM2.5 samples were collected daily at the Lin'an regional background station (LA) in Zhejiang, China during 2014-2015 and the major chemical components including organic carbon (OC), elemental carbon (EC) and water-soluble inorganic ions (WSII) were determined. Backward trajectory clustering and potential source contribution function (PSCF) were adopted for identifying the transport pathways and potential source regions of PM2.5 at LA. The annual mean concentration was 68.9 ± 28.3 μg m-3, indicating severe pollution in East China. Obvious seasonal variations were found, with highest level in winter and lowest in summer. Carbonaceous aerosols and WSII were the predominant compositions, accounting for 30.7% and 53.5% of PM2.5, respectively. Secondary inorganic ions (SO42-, NO3-, and NH4+) made a total contribution of 45.2% to PM2.5. Heterogeneous formation played a dominant role in SO42- formation and NH4+ formation promoted NO3- formation. Stationary sources played a more important role than mobile sources based on NO3-/SO42- ratio of 0.53. Aerosol environment at LA was ammonium-poor and SO42- was only neutralized sufficiently by NH4+ with the predominant production of (NH4)2SO4 in winter. Four major transport pathways of air masses at LA were found based on trajectory clustering. Air masses from the northwest Gobi areas passing over the heavily polluted regions in North and Central China had the highest levels of PM2.5, followed by the air masses from Central China. PSCF results suggested that surrounding areas in the Yangtze River Delta region were major regional origins of PM2.5 and its major components. Northern region was an important origin for carbonaceous components, and southwestern region was significant for secondary inorganic ions. This study helps understand PM2.5 characteristics, identify potential source regions and effectively control PM2.5 in East China.

  10. Antioxidant Activity of Individual Steryl Ferulates from Various Cereal Grain Sources.

    PubMed

    Zhu, Dan; Sánchez-Ferrer, Antoni; Nyström, Laura

    2016-02-26

    Steryl ferulates (SFs) are a subclass of bioactive lipids contributing to the health-promoting effects of whole grains. Most related studies focus on γ-oryzanol, a SF mixture from rice, since individual steryl ferulates are not commercially available. There is little evidence that individual SFs may vary in their bioactivity. The aim of this study was to evaluate the antioxidant activity of eight individual SFs by determining their radical scavenging capacity. Additional molecular properties of the individual SFs were determined by molecular simulation in order to identify correlations with their antioxidant activities. Our study demonstrates that individual SFs exhibit 1,1-diphenyl-2-picrylhydrazyl radical, hydroxyl radical, and superoxide anion radical scavenging abilities with subtle differences that were highly dependent on the kind of reaction taking place. The grouping of SFs by principle component analysis was mainly attributed to molecular properties, not antioxidant activities. Solvation energy was significantly correlated with some experimental observations. To our knowledge, this is the first study to evaluate the antioxidant activity of eight individual steryl ferulates from different sources. Results of this work will provide better insight into the antioxidant activity of SFs and the health benefits of whole grains.

  11. The multidimensional background of malnutrition among rural older individuals in Bangladesh--a challenge for the Millennium Development Goal.

    PubMed

    Ferdous, Tamanna; Kabir, Zarina Nahar; Wahlin, Ake; Streatfield, Kim; Cederholm, Tommy

    2009-12-01

    To investigate the associations and relative impact of illness, socio-economic and social indicators for nutritional status among elderly persons in rural Bangladesh. A multidisciplinary, cross-sectional study employing home interviews to collect information on demographic, socio-economic and social status; clinical examination to classify medical diagnoses; and Mini Nutritional Assessment (MNA) to assess the nutritional status of each participant. Matlab, Bangladesh. A total of 625 randomly selected individuals (>or=60 years of age) participated in home interviews and 473 underwent clinical examination. Complete information on nutritional status was available for 457 individuals, median age 68 years, 55 % women. Twenty-six per cent of the elderly participants were undernourished and 62 % were at risk of malnutrition according to MNA. More than three-quarters of the participants had acute infections, 66 % suffered from chronic illnesses, 36 % had sensory impairments and 81 % were suffering from gastrointestinal disorders. Acute infections (P < 0.001), gastrointestinal disorders (P < 0.01), depressive symptoms (P < 0.001) and impaired cognitive function (P < 0.01) were significantly and independently associated with poorer nutritional status. Moreover, female gender (P < 0.05), having no income (P < 0.01), being illiterate (P < 0.01) and not receiving regular financial support (P < 0.05) were also independently associated with poor nutritional status. Malnutrition among elderly people in rural Bangladesh is associated with female gender, medical, psychological, socio-economic and social indicators. A multidimensional approach is probably needed to reduce undernutrition in older populations in low-income countries like Bangladesh.

  12. Infrared-faint radio sources: a cosmological view. AGN number counts, the cosmic X-ray background and SMBH formation

    NASA Astrophysics Data System (ADS)

    Zinn, P.-C.; Middelberg, E.; Ibar, E.

    2011-07-01

    Context. Infrared-faint radio sources (IFRS) are extragalactic emitters clearly detected at radio wavelengths but barely detected or undetected at optical and infrared wavelengths, with 5σ sensitivities as low as 1 μJy. Aims: Spectral energy distribution (hereafter SED) modelling and analyses of their radio properties indicate that IFRS are consistent with a population of (potentially extremely obscured) high-redshift AGN at 3 ≤ z ≤ 6. We demonstrate some astrophysical implications of this population and compare them to predictions from models of galaxy evolution and structure formation. Methods: We compiled a list of IFRS from four deep extragalactic surveys and extrapolated the IFRS number density to a survey-independent value of (30.8 ± 15.0) deg-2. We computed the IFRS contribution to the total number of AGN in the Universe to account for the cosmic X-ray background. By estimating the black hole mass contained in IFRS, we present conclusions for the SMBH mass density in the early universe and compare it to relevant simulations of structure formation after the Big Bang. Results: The number density of AGN derived from the IFRS density was found to be ~310 deg-2, which is equivalent to a SMBH mass density of the order of 103 M⊙ Mpc-3 in the redshift range 3 ≤ z ≤ 6. This produces an X-ray flux of 9 × 10-16 W m-2 deg-2 in the 0.5-2.0 keV band and 3 × 10-15 W m-2 deg-2 in the 2.0-10 keV band, in agreement with the missing unresolved components of the Cosmic X-ray Background. To address SMBH formation after the Big Bang we invoke a scenario involving both halo gas accretion and major mergers.

  13. Sizing up the individual market for health insurance: a comparison of survey and administrative data sources.

    PubMed

    Abraham, Jean M; Karaca-Mandic, Pinar; Boudreaux, Michel

    2013-08-01

    Provisions within the Affordable Care Act, including the introduction of subsidized, Exchange-based coverage for lower income Americans lacking access to employer coverage, are expected to greatly expand the size and importance of the individual market. Using multiple federal surveys and administrative data from the National Association of Insurance Commissioners, we generate national-, regional-, and state-level estimates of the individual market. In 2009, the number of nonelderly persons with individual coverage ranged from 9.55 million in the Medical Expenditure Panel Survey to 25.3 million in the American Community Survey. Notable differences also exist between survey estimates and National Association of Insurance Commissioners administrative counts, an outcome likely driven by variation in the type and measurement of individual coverage considered by surveys relative to administrative data. Future research evaluating the impact of the Affordable Care Act coverage provisions must be mindful of differences across surveys and administrative sources as it relates to the measurement of individual market coverage.

  14. Seismic data collection from water gun and industrial background sources in the Chicago Sanitary and Ship Canal area, Illinois, 2011

    USGS Publications Warehouse

    Morrow, William S.; Carpenter, Phillip J.; Adams, Ryan F.

    2015-01-01

    The water gun is a tool adapted from deep marine geophysical surveys that is being evaluated for use as an acoustic fish deterrent to control the movement of invasive marine species. The water gun creates a seismic signal by using a compressed air discharge to move a piston rapidly within the water, resulting in an implosion. This energy pulse may be able to modify fish behavior or destroy marine life, such as the Asian carp, at some distance. The effects of this energy pulse on structures in the Chicago Sanitary and Ship Canal (CSSC), such as canal walls, shore lines, and lock structures, are not known. The potential effects of the use of a water gun on structures was identified as a concern in the CSSC and was assessed relative to existing background sources during this study. During September 2011, two water guns with piston sizes of 80 and 343 cubic inches, respectively, were tested in the CSSC at varying pressures and distances from a canal wall consisting of dolomite and dolomite setblock. Seismic data were collected during these water gun firings using geophones on land, in boreholes, and at the canal wall interface. Data were collected at varying depths in the canal water using hydrophones. Seismic data were also collected during the occurrences of barge traffic, railroad traffic located near the electric fish barrier in Lemont, and coal-loading operations at a coal power plant near the electric fish barrier. In general, energy produced by barge and railroad sources was less than energy created by the water gun. Energy levels produced by coal-loading operations at least 200 feet from geophones were approximately four times lower than energy levels measured during water gun operations.

  15. Localizing epileptogenic regions in partial epilepsy using three-dimensional statistical parametric maps of background EEG source spectra.

    PubMed

    Alper, Kenneth; Raghavan, Manoj; Isenhart, Robert; Howard, Bryant; Doyle, Werner; John, Roy; Prichep, Leslie

    2008-02-01

    This preliminary study sought to localize epileptogenic regions in patients with partial epilepsy by analysis of interictal EEG activity utilizing variable resolution electromagnetic tomography (VARETA), a three-dimensional quantitative electroencephalographic (QEEG) frequency-domain distributed source modeling technique. The very narrow band (VNB) spectra spanned the frequency range 0.39 Hz to 19.1 Hz, in 0.39 Hz steps. These VNB spectra were compared to normative data and transformed to provide Z-scores for every scalp derivation, and the spatial distributions of the probable EEG generators of the most abnormal values were displayed on slices from a probabilistic MRI atlas. Each voxel was color-coded to represent the significance of the deviation relative to age appropriate normative values. We compared the resulting three-dimensional images to the localization of epileptogenic regions based on invasive intracranial EEG recordings of seizure onsets. The VARETA image indicated abnormal interictal spectral power values in regions of seizure onset identified by invasive monitoring, mainly in delta and theta range (1.5 to 8.0 Hz). The VARETA localization of the most abnormal voxel was congruent with the epileptogenic regions identified by intracranial recordings with regard to hemisphere in all 6 cases, and with regard to lobe in 5 cases. In contrast, abnormal findings with routine EEG agreed with invasive monitoring with regard to hemisphere in 3 cases and with regard to lobe in 2 cases. These results suggest that analysis of background interictal EEG utilizing distributed source models should be investigated further in clinical epilepsy.

  16. Radio source calibration for the Very Small Array and other cosmic microwave background instruments at around 30 GHz

    NASA Astrophysics Data System (ADS)

    Hafez, Yaser A.; Davies, Rod D.; Davis, Richard J.; Dickinson, Clive; Battistelli, Elia S.; Blanco, Francisco; Cleary, Kieran; Franzen, Thomas; Genova-Santos, Ricardo; Grainge, Keith; Hobson, Michael P.; Jones, Michael E.; Lancaster, Katy; Lasenby, Anthony N.; Padilla-Torres, Carmen P.; Rubiño-Martin, José Alberto; Rebolo, Rafael; Saunders, Richard D. E.; Scott, Paul F.; Taylor, Angela C.; Titterington, David; Tucci, Marco; Watson, Robert A.

    2008-08-01

    Accurate calibration of data is essential for the current generation of cosmic microwave background (CMB) experiments. Using data from the Very Small Array (VSA), we describe procedures which will lead to an accuracy of 1 per cent or better for experiments such as the VSA and CBI. Particular attention is paid to the stability of the receiver systems, the quality of the site and frequent observations of reference sources. At 30 GHz the careful correction for atmospheric emission and absorption is shown to be essential for achieving 1 per cent precision. The sources for which a 1 per cent relative flux density calibration was achieved included Cas A, Cyg A, Tau A and NGC 7027 and the planets Venus, Jupiter and Saturn. A flux density, or brightness temperature in the case of the planets, was derived at 33 GHz relative to Jupiter which was adopted as the fundamental calibrator. A spectral index at ~30 GHz is given for each. Cas A, Tau A, NGC 7027 and Venus were examined for variability. Cas A was found to be decreasing at 0.394 +/- 0.019 per cent yr-1 over the period 2001 March to 2004 August. In the same period Tau A was decreasing at 0.22 +/- 0.07 per cent yr-1. A survey of the published data showed that the planetary nebula NGC 7027 decreased at 0.16 +/- 0.04 per cent yr-1 over the period 1967-2003. Venus showed an insignificant (1.5 +/- 1.3 per cent) variation with Venusian illumination. The integrated polarization of Tau A at 33 GHz was found to be 7.8 +/- 0.6 per cent at position angle =148° +/- 3°.

  17. Source apportionment of submicron organic aerosol at an urban background and a road site in Barcelona, Spain

    NASA Astrophysics Data System (ADS)

    Alier, M.; van Drooge, B. L.; Dall'Osto, M.; Querol, X.; Grimalt, J. O.; Tauler, R.

    2013-04-01

    This study investigates the contribution of potential sources to the sub-micron (PM1) organic aerosol (OA) simultaneously detected at an urban background (UB) and a road site (RS) in Barcelona during the 30 days of the intensive field campaign of SAPUSS (Solving Aerosol Problems by Using Synergistic Strategies, September-October 2010). 103 filters at 12 h sampling time resolution were collected at both sites. Thirty-six neutral and polar organic compounds of known emission sources and photo-chemical transformation processes were analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). The concentrations of the trace chemical compounds analyzed are herein presented and discussed. Additionally, OA source apportionment was performed by Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) and six OA components were identified at both sites: two were of primary anthropogenic OA origin, three of secondary OA origin while a sixth one was not clearly defined. Primary organics from emissions of local anthropogenic activities (Urban primary organic aerosol, Urban POA) contributed for 43% (1.5 μg OC m-3) and 18% (0.4 μg OC m-3) to OA in RS and UB, respectively. A secondary primary source - biomass burning (BBOA) - was found in all the samples (average values 7% RS; 12% UB; 0.3 μg OC m-3), but this component was substantially contributing to OA only when the sampling sites were under influence of regional air mass circulation. Three Secondary Organic Aerosol (SOA) components (describing overall 60% of the variance) were observed in the urban ambient PM1. Products of isoprene oxidation (SOA ISO), i.e. 2-methylglyceric acid, C5 alkene triols and 2-methyltetrols, showed the highest abundance at both sites when the city was under influence of inland air masses. The overall concentrations of SOA ISO were similar at both sites (0.4 and 0.3 μg m-3, 16% and 7%, at UB and RS, respectively). By contrast, a SOA biogenic component attributed to α-pinene oxidation (SOA

  18. Source apportionment of submicron organic aerosol at an urban background and a road site in Barcelona (Spain) during SAPUSS

    NASA Astrophysics Data System (ADS)

    Alier, M.; van Drooge, B. L.; Dall'Osto, M.; Querol, X.; Grimalt, J. O.; Tauler, R.

    2013-10-01

    This study investigates the contribution of potential sources to the submicron (PM1) organic aerosol (OA) simultaneously detected at an urban background (UB) and a road site (RS) in Barcelona during the 30 days of the intensive field campaign of SAPUSS (Solving Aerosol Problems by Using Synergistic Strategies, September-October 2010). A total of 103 filters at 12 h sampling time resolution were collected at both sites. Thirty-six neutral and polar organic compounds of known emission sources and photo-chemical transformation processes were analyzed by gas chromatography-mass spectrometry (GC-MS). The concentrations of the trace chemical compounds analyzed are herein presented and discussed. Additionally, OA source apportionment was performed by multivariate curve resolution-alternating least squares (MCR-ALS) and six OA components were identified at both sites: two were of primary anthropogenic OA origin and three of secondary OA origin, while a sixth one was not clearly defined. Primary organics from emissions of local anthropogenic activities (urban primary organic aerosol, or POA Urban), mainly traffic emissions but also cigarette smoke, contributed 43% (1.5 μg OC m-3) and 18% (0.4 μg OC m-3) to OA at RS and UB, respectively. A secondary primary source - biomass burning (BBOA) - was found in all the samples (average values 7% RS; 12% UB; 0.3 μg OC m-3), but this component was substantially contributing to OA only when the sampling sites were under influence of regional air mass circulation (REG.). Three secondary organic aerosol (SOA) components (describing overall 60% of the variance) were observed in the urban ambient PM1. Products of isoprene oxidation (SOA ISO) - i.e. 2-methylglyceric acid, C5 alkene triols and 2-methyltetrols - showed the highest abundance at both sites when the city was under influence of inland air masses. The overall concentrations of SOA ISO were similar at both sites (0.4 and 0.3 μg m-3, or 16% and 7%, at UB and RS, respectively

  19. Global lung cancer risk from PAH exposure highly depends on emission sources and individual susceptibility

    PubMed Central

    Shen, Huizhong; Tao, Shu; Liu, Junfeng; Huang, Ye; Chen, Han; Li, Wei; Zhang, Yanyan; Chen, Yuanchen; Su, Shu; Lin, Nan; Xu, Yinyin; Li, Bengang; Wang, Xilong; Liu, Wenxin

    2014-01-01

    The health impacts of polycyclic aromatic hydrocarbons (PAHs), the most concerning organic pollutants, depend not only on the locations and strengths of emission sources, but also on individual susceptibility. Moreover, trans-boundary transport makes them a global concern. In this study, a comprehensive analysis of the global health impacts of polycyclic aromatic hydrocarbons (PAHs) in ambient air is presented. Model resolution is critical in exposure modelling. Globally, incremental lifetime lung cancer risk (ILCR) induced by ambient PAH exposure is 3.1 × 10−5. If the individual susceptibility was not taken into consideration, the overall risk would be underestimated by 55% and the proportion of highly vulnerable population would be underestimated by more than 90%. Emphasizing on individual susceptibility, our study provides an instrumental revision of current risk assessment methodology. In terms of lung cancer risk, the most important sources are combustion of biomass fuels (40%) and fossil fuels (14%) in the residential/commercial sector, coke (13%) and aluminium (12%) production, and motor vehicles (9%). PAHs can travel long distance globally especially within the Eurasian continent. Still, the risk is dominantly contributed by local. PMID:25297709

  20. Global lung cancer risk from PAH exposure highly depends on emission sources and individual susceptibility

    NASA Astrophysics Data System (ADS)

    Shen, Huizhong; Tao, Shu; Liu, Junfeng; Huang, Ye; Chen, Han; Li, Wei; Zhang, Yanyan; Chen, Yuanchen; Su, Shu; Lin, Nan; Xu, Yinyin; Li, Bengang; Wang, Xilong; Liu, Wenxin

    2014-10-01

    The health impacts of polycyclic aromatic hydrocarbons (PAHs), the most concerning organic pollutants, depend not only on the locations and strengths of emission sources, but also on individual susceptibility. Moreover, trans-boundary transport makes them a global concern. In this study, a comprehensive analysis of the global health impacts of polycyclic aromatic hydrocarbons (PAHs) in ambient air is presented. Model resolution is critical in exposure modelling. Globally, incremental lifetime lung cancer risk (ILCR) induced by ambient PAH exposure is 3.1 × 10-5. If the individual susceptibility was not taken into consideration, the overall risk would be underestimated by 55% and the proportion of highly vulnerable population would be underestimated by more than 90%. Emphasizing on individual susceptibility, our study provides an instrumental revision of current risk assessment methodology. In terms of lung cancer risk, the most important sources are combustion of biomass fuels (40%) and fossil fuels (14%) in the residential/commercial sector, coke (13%) and aluminium (12%) production, and motor vehicles (9%). PAHs can travel long distance globally especially within the Eurasian continent. Still, the risk is dominantly contributed by local.

  1. Global lung cancer risk from PAH exposure highly depends on emission sources and individual susceptibility.

    PubMed

    Shen, Huizhong; Tao, Shu; Liu, Junfeng; Huang, Ye; Chen, Han; Li, Wei; Zhang, Yanyan; Chen, Yuanchen; Su, Shu; Lin, Nan; Xu, Yinyin; Li, Bengang; Wang, Xilong; Liu, Wenxin

    2014-10-09

    The health impacts of polycyclic aromatic hydrocarbons (PAHs), the most concerning organic pollutants, depend not only on the locations and strengths of emission sources, but also on individual susceptibility. Moreover, trans-boundary transport makes them a global concern. In this study, a comprehensive analysis of the global health impacts of polycyclic aromatic hydrocarbons (PAHs) in ambient air is presented. Model resolution is critical in exposure modelling. Globally, incremental lifetime lung cancer risk (ILCR) induced by ambient PAH exposure is 3.1 × 10(-5). If the individual susceptibility was not taken into consideration, the overall risk would be underestimated by 55% and the proportion of highly vulnerable population would be underestimated by more than 90%. Emphasizing on individual susceptibility, our study provides an instrumental revision of current risk assessment methodology. In terms of lung cancer risk, the most important sources are combustion of biomass fuels (40%) and fossil fuels (14%) in the residential/commercial sector, coke (13%) and aluminium (12%) production, and motor vehicles (9%). PAHs can travel long distance globally especially within the Eurasian continent. Still, the risk is dominantly contributed by local.

  2. Wavelength-Tunable Electroluminescent Light Sources from Individual Ga-Doped ZnO Microwires.

    PubMed

    Jiang, Mingming; He, Gaohang; Chen, Hongyu; Zhang, Zhenzhong; Zheng, Lingxia; Shan, Chongxin; Shen, Dezhen; Fang, Xiaosheng

    2017-03-07

    Electrically driven wavelength-tunable light emission from biased individual Ga-doped ZnO microwires (ZnO:Ga MWs) is demonstrated. Single crystalline ZnO:Ga MWs with different Ga-doping concentrations have been synthesized using a one-step chemical vapor deposition method. Strong electrically driven light emission from individual ZnO:Ga MW based devices is realized with tunable colors, and the emission region is localized toward the center of the wires. Increasing Ga-doping concentration in the MWs can lead to the redshift of electroluminescent emissions in the visible range. Interestingly, owing to the lack of rectification characteristics, relevant electrical measurement results show that the alternating current-driven light emission functions excellently on the ZnO:Ga MWs. Consequently, individual ZnO:Ga MWs, which can be analogous to incandescent sources, offer unique possibilities for future electroluminescence light sources. This typical multicolor emitter can be used to rival and complement other conventional semiconductor devices in displays and lighting.

  3. An inter-comparison of PM2.5 at urban and urban background sites: Chemical characterization and source apportionment

    NASA Astrophysics Data System (ADS)

    Cesari, D.; Donateo, A.; Conte, M.; Merico, E.; Giangreco, A.; Giangreco, F.; Contini, D.

    2016-06-01

    A measurement campaign was performed between 04/03/2013 and 17/07/2013 for simultaneous collection of PM2.5 samples in two nearby sites in southeastern Italy: an urban site and an urban background site. PM2.5 at the two sites were similar; however, the chemical composition and the contributions of the main sources were significantly different. The coefficients of divergence (CODs) showed spatial heterogeneity of EC (higher at the urban site because of traffic emissions) and of all metals. Major ions (NH4+, Na+, and SO42 -) and OC had low CODs, suggesting a homogeneous distribution of sea spray, secondary sulfate, and secondary organic matter (SOM = 1.6*OCsec, where OCsec is the secondary OC). The strong correlations between Na+ and Cl-, and the low Cl-/Na+ ratios, suggested the presence of aged sea spray with chloride depletion (about 79% of Cl-) and formation of sodium nitrate at both sites. In both sites, the non-sea-salt sulfate was about 97% of sulfate, and the strong correlation between SO42 - and NH4+ indicated that ammonium was present as ammonium sulfate. However, during advection of Saharan Dust, calcium sulfate was present rather than ammonium sulfate. The source apportionment was performed using the Positive Matrix Factorization comparing outputs of model EPA PMF 3.0 and 5.0 version. Six aerosol sources were identified at both sites: traffic, biomass burning, crustal-resuspended dust, secondary nitrate, marine aerosol, and secondary sulfate. The PMF3.0 model was not completely able, in these sites, to separate marine contribution from secondary nitrate and secondary sulfate from OC, underestimating the marine contribution and overestimating the secondary sulfate with respect to stoichiometric calculations. The application of specific constraints on PMF5.0 provided cleaner profiles, improving the comparison with stoichiometric calculations. The seasonal trends revealed larger biomass burning contributions during the cold period at both sites due to

  4. Stigma: a Unique Source of Distress for Family Members of Individuals with Mental Illness.

    PubMed

    Muralidharan, Anjana; Lucksted, Alicia; Medoff, Deborah; Fang, Li Juan; Dixon, Lisa

    2016-07-01

    To distinguish the impact of mental illness stigma from that of other negative caregiving experiences, this study examined the unique relationships between stigma and caregiver/family functioning. Adult relatives (n = 437) of individuals with mental illness completed questionnaires regarding caregiving experiences, distress, empowerment, and family functioning, as part of a larger study. Regression analyses examined the relationship between stigma and caregiver/family variables, while controlling for other negative caregiving experiences. Stigma was uniquely associated with caregiver distress, empowerment, and family functioning. Mental illness stigma is a potent source of distress for families and an important target of family services.

  5. Regional background aerosols over the Balearic Islands over the last 3 years: ground-based concentrations, atmospheric deposition and sources

    NASA Astrophysics Data System (ADS)

    Cerro, Jose Carlos; Pey, Jorge; Bujosa, Carles; Caballero, Sandra; Alastuey, Andres; Sicard, Michael; Artiñano, Begoña; Querol, Xavier

    2013-04-01

    In the context of the ChArMEx (The Chemistry-Aerosol Mediterranean Experiment, https://charmex.lsce.ipsl.fr) initiative, a 3-year study over a regional background environment (Can Llompart, CLP) in Mallorca has been conducted. Ground-based PM mass concentrations, gaseous pollutants and meteorological parameters were continuously registered from 2010 to 2012. Since the beginning of the campaign, PM10 daily samples for chemical determinations were obtained every 4 days, and dry and wet deposition samples were collected every week. Moreover, additional instruments (condensation particle counter, multi-angle absorption photometer, airpointer, sequential high and low volume samplers) were deployed during intensive filed campaigns in 2011 and 2012, as well as the sampling frequency was intensified. In the laboratory, PM samples were analyzed for inorganic compounds, and organic and elemental carbon following different approaches. In addition, n-alkanes, iso-alkanes, antiso-alkanes, levoglucosan, alkanoic acids and cholesterol were determined by GC-MS chromatography in a selection of 30 samples. Mean PM10, PM2.5 and PM1 concentrations in the period 2010-2012 reached 17, 11, and 8 µg/m3 respectively. Mass concentrations displayed marked seasonal trends, with much higher background levels in summer due to stagnant conditions over the western Mediterranean and increased frequency of Saharan dust events. Likewise, diverse-intensity peaks of coarse PM due to African dust inputs were observed along the year. On average, African dust in PM10 accounted for 1.0-1.5 µg/m3. Sporadic pollution events, characterized by most of the particles in the fine mode, were related to the transport of anthropogenic polluted air masses from central and eastern Europe. Wet and dry atmospheric deposition samples are being analyzed to quantify the deposition fluxes for different soluble and insoluble compounds. On average, PM10 composition is made up of organic matter (23%), mineral components (17

  6. CHANG-ES. III. UGC 10288—An edge-on galaxy with a background double-lobed radio source

    SciTech Connect

    Irwin, Judith; Krause, Marita; Beck, Rainer; English, Jayanne; Murphy, Eric; Wiegert, Theresa; Heald, George; Walterbos, Rene; Rand, Richard J.; Porter, Troy E-mail: mkrause@mpifr-bonn.mpg.de E-mail: jayanne_english@umanitoba.ca E-mail: twiegert@astro.queensu.ca E-mail: rwalterb@nmsu.edu E-mail: tporter@stanford.edu

    2013-12-01

    This third paper in the Continuum Halos in Nearby Galaxies—an EVLA Survey (CHANG-ES) series shows the first results from our regular data taken with the Karl G. Jansky Very Large Array. The edge-on galaxy, UGC 10288, has been observed in the B, C, and D configurations at L band (1.5 GHz) and in the C and D configurations at C band (6 GHz) in all polarization products. We show the first spatially resolved images of this galaxy in these bands, the first polarization images, and the first composed image at an intermediate frequency (4.1 GHz) which has been formed from a combination of all data sets. A surprising new result is the presence of a strong, polarized, double-lobed extragalactic radio source (CHANG-ES A) almost immediately behind the galaxy and perpendicular to its disk. The core of CHANG-ES A has an optical counterpart (SDSS J161423.28–001211.8) at a photometric redshift of z {sub phot} = 0.39; the southern radio lobe is behind the disk of UGC 10288 and the northern lobe is behind the halo region. This background ''probe'' has allowed us to do a preliminary Faraday rotation analysis of the foreground galaxy, putting limits on the regular magnetic field and electron density in the halo of UGC 10288 in regions in which there is no direct detection of a radio continuum halo. We have revised the flux densities of the two sources individually as well as the star formation rate (SFR) for UGC 10288. The SFR is low (0.4-0.5 M {sub ☉} yr{sup –1}) and the galaxy has a high thermal fraction (44% at 6 GHz), as estimated using both the thermal and non-thermal SFR calibrations of Murphy et al. UGC 10288 would have fallen well below the CHANG-ES flux density cutoff, had it been considered without the brighter contribution of the background source. UGC 10288 shows discrete high-latitude radio continuum features, but it does not have a global radio continuum halo (exponential scale heights are typically ≈1 kpc averaged over regions with and without extensions

  7. Cross-correlating Cosmic IR and X-ray Background Fluctuations: Evidence of Significant Black Hole Populations Among the CIB Sources

    NASA Technical Reports Server (NTRS)

    Cappelluti, N.; Kashlinsky, A.; Arendt, R. G.; Comastri, A.; Fazio, G. G.; Finoguenov, A.; Hasinger, G.; Mather, J. C.; Miyaji, T; Moseley, S. H.

    2013-01-01

    In order to understand the nature of the sources producing the recently uncovered cosmic infrared background (CIB) fluctuations, we study cross-correlations between the fluctuations in the source-subtracted CIB from Spitzer/IRAC data and the unresolved cosmic X-ray background from deep Chandra observations. Our study uses data from the EGS/AEGIS field, where both data sets cover an approx = 8' x 45' region of the sky. Our measurement is the cross-power spectrum between the IR and X-ray data. The cross-power signal between the IRAC maps at 3.6 micron and 4.5 micron and the Chandra [0.5-2] keV data has been detected, at angular scales approx >20'', with an overall significance of approx = 3.8 sigma and approx. = 5.6 sigma, respectively. At the same time we find no evidence of significant cross-correlations at the harder Chandra bands. The cross-correlation signal is produced by individual IR sources with 3.6 micron and 4.5 micron magnitudes m(sub AB) approx. > 25-26 and [0.5-2] keV X-ray fluxes << 7 × 10(exp -177 erg sq. cm/ s. We determine that at least 15%-25% of the large scale power of the CIB fluctuations is correlated with the spatial power spectrum of the X-ray fluctuations. If this correlation is attributed to emission from accretion processes at both IR and X-ray wavelengths, this implies a much higher fraction of accreting black holes than among the known populations. We discuss the various possible origins for the cross-power signal and show that neither local foregrounds nor the known remaining normal galaxies and active galactic nuclei can reproduce the measurements. These observational results are an important new constraint on theoretical modeling of the near-IR CIB fluctuations. local foregrounds, nor the known remaining normal galaxies and active galactic nuclei (AGN) can reproduce the measurements. These observational results are an important new constraint on theoretical modeling of the near-IR CIB fluctuations

  8. CROSS-CORRELATING COSMIC INFRARED AND X-RAY BACKGROUND FLUCTUATIONS: EVIDENCE OF SIGNIFICANT BLACK HOLE POPULATIONS AMONG THE CIB SOURCES

    SciTech Connect

    Cappelluti, N.; Comastri, A.; Kashlinsky, A.; Mather, J. C.; Moseley, S. H.; Arendt, R. G.; Finoguenov, A.; Fazio, G. G.; Hasinger, G.; Miyaji, T.

    2013-05-20

    In order to understand the nature of the sources producing the recently uncovered cosmic infrared background (CIB) fluctuations, we study cross-correlations between the fluctuations in the source-subtracted CIB from Spitzer/IRAC data and the unresolved cosmic X-ray background from deep Chandra observations. Our study uses data from the EGS/AEGIS field, where both data sets cover an {approx_equal} 8' Multiplication-Sign 45' region of the sky. Our measurement is the cross-power spectrum between the IR and X-ray data. The cross-power signal between the IRAC maps at 3.6 {mu}m and 4.5 {mu}m and the Chandra [0.5-2] keV data has been detected, at angular scales {approx}> 20'', with an overall significance of {approx_equal} 3.8{sigma} and {approx_equal} 5.6{sigma}, respectively. At the same time we find no evidence of significant cross-correlations at the harder Chandra bands. The cross-correlation signal is produced by individual IR sources with 3.6 {mu}m and 4.5 {mu}m magnitudes m{sub AB} {approx}> 25-26 and [0.5-2] keV X-ray fluxes <<7 Multiplication-Sign 10{sup -17} erg cm{sup 2} s{sup -1}. We determine that at least 15%-25% of the large scale power of the CIB fluctuations is correlated with the spatial power spectrum of the X-ray fluctuations. If this correlation is attributed to emission from accretion processes at both IR and X-ray wavelengths, this implies a much higher fraction of accreting black holes than among the known populations. We discuss the various possible origins for the cross-power signal and show that neither local foregrounds nor the known remaining normal galaxies and active galactic nuclei can reproduce the measurements. These observational results are an important new constraint on theoretical modeling of the near-IR CIB fluctuations.

  9. Do individual Spitzer young stellar object candidates enclose multiple UKIDSS sources?

    NASA Astrophysics Data System (ADS)

    Morales, Esteban F. E.; Robitaille, Thomas P.

    2017-02-01

    Aims: We analyze United Kingdom Infrared Deep Sky Survey (UKIDSS) observations of a sample of 8325 objects taken from a catalog of intrinsically red sources selected in the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE). Given the differences in angular resolution (factor >2 better in UKIDSS), our aim is to investigate whether there are multiple UKIDSS sources that might all contribute to the GLIMPSE flux, or whether there is only one dominant UKIDSS counterpart. We then study possible corrections to estimates of the star formation rate (SFR) based on counts of GLIMPSE young stellar objects (YSOs). This represents an exploratory work toward the construction of a hierarchical YSO catalog. Methods: After performing PSF fitting photometry in the UKIDSS data, we implemented a technique to recognize the dominant UKIDSS sources automatically by evaluating their match with the spectral energy distribution (SED) of the associated GLIMPSE red sources. This is a generic method that could be robustly applied for matching SEDs across gaps at other wavelengths. Results: We found that most (87.0 ± 1.6%) of the candidate YSOs from the GLIMPSE red source catalog have only one dominant UKIDSS counterpart that matches the mid-infrared SED (fainter associated UKIDSS sources might still be present). Although at first sight this could seem surprising, given that YSOs are typically in clustered environments, we argue that within the mass range covered by the GLIMPSE YSO candidates (intermediate to high masses), clustering with objects with comparable mass is unlikely at the GLIMPSE resolution. Indeed, by performing simple clustering experiments based on a population synthesis model of Galactic YSOs, we found that although 60% of the GLIMPSE YSO enclose at least two UKIDSS sources, in general only one dominates the flux. Conclusions: No significant corrections are needed for estimates of the SFR of the Milky Way based on the assumption that the GLIMPSE YSOs

  10. [Experimental study on methane potentials of source-separated BMW and individual waste materials].

    PubMed

    Feng, Lei; Li, Run-dong; Li, Yan-ji; Ke, Xin; Wei, Li-hong; Luo, Xiao-song

    2008-08-01

    A laboratory procedure is described for measuring methane potentials of source-separated bio-organic municipal waste (BMW). Triplicate reactors with about 20 grams fresh material were incubated at 37 degrees C with 300 mL inoculum from Shenyang wastewater treatment plant and the methane production was followed over a 50 d period by regular measurement of methane on a gas chromatograph. At 37 degrees C, the methane production efficiency of source-separated BMW and individual waste materials was: starch > BMW > protein > food oil > fat > paper. For the source-separated BMW,starch,protein,food oil,fat and paper, the methane potential (CH4/VS) of 218.15, 209.11, 194.20, 238.86, 257.82 and 131.41 mL/g were found,and ultimate biodegradability of 6 difference materials were 67.73%, 72.88%, 65.84%, 78.38%, 74.11% and 47.98%, respectively.

  11. The spectroscopy of individual terrestrial gamma-ray flashes: Constraining the source properties

    NASA Astrophysics Data System (ADS)

    Mailyan, B. G.; Briggs, M. S.; Cramer, E. S.; Fitzpatrick, G.; Roberts, O. J.; Stanbro, M.; Connaughton, V.; McBreen, S.; Bhat, P. N.; Dwyer, J. R.

    2016-11-01

    We report on the spectral analysis of individual terrestrial gamma-ray flashes (TGFs) observed with the Fermi Gamma-ray Burst Monitor (GBM). The large GBM TGF sample provides 46 events suitable for individual spectral analysis: sufficiently bright, localized by ground-based radio, and with the gamma rays reaching a detector unobstructed. These TGFs exhibit diverse spectral characteristics that are hidden when using summed analysis methods. We account for the low counts in individual TGFs by using Poisson likelihood, and we also consider instrumental effects. The data are fit with models obtained from Monte Carlo simulations of the large-scale Relativistic Runaway Electron Avalanche (RREA) model, including propagation through the atmosphere. Source altitudes ranging from 11.6 to 20.2 km are simulated. Two beaming geometries were considered: In one, the photons retain the intrinsic distribution from scattering (narrow), and in the other, the photons are smeared into a wider beam (wide). Several TGFs are well fit only by narrow-beam models, while others favor wide-beam models. Large-scale RREA models can accommodate both narrow and wide beams, with narrow beams suggest large-scale RREA in organized electric fields while wide beams may imply converging or diverging electric fields. Wide beams are also consistent with acceleration in the electric fields of lightning leaders, but the TGFs that favor narrow-beam models appear inconsistent with some lightning leader models.

  12. Characteristics, sources and evolution of fine aerosol (PM1) at urban, coastal and forest background sites in Lithuania

    NASA Astrophysics Data System (ADS)

    Masalaite, A.; Holzinger, R.; Remeikis, V.; Röckmann, T.; Dusek, U.

    2017-01-01

    The chemical and isotopic composition of organic aerosol (OA) samples collected on PM1 filters was determined as a function of desorption temperature to investigate the main sources of organic carbon and the effects of photochemical processing on atmospheric aerosol. The filter samples were collected at an urban (54°38‧ N, 25°18‧ E), coastal (55°55‧ N, 21°00‧ E) and forest (55°27‧ N, 26°00' E) site in Lithuania in March 2013. They can be interpreted as winter-time samples because the monthly averaged temperature was -4 °C. The detailed chemical composition of organic compounds was analysed with a thermal desorption PTR-MS. The mass concentration of organic aerosol at the forest site was roughly by a factor of 30 lower than at the urban and coastal site. This fact could be an indication that in this cold month the biogenic secondary organic aerosol (SOA) formation was very low. Moreover, the organic aerosol collected at the forest site was more refractory and contained a larger fraction of heavy molecules with m/z > 200. The isotopic composition of the aerosol was used to differentiate the two main sources of organic aerosol in winter, i.e. biomass burning (BB) and fossil fuel (FF) combustion. Organic aerosol from biomass burning is enriched in 13C compared to OA from fossil fuel emissions. δ13COC values of the OA samples showed a positive correlation with the mass fraction of several individual organic compounds. Most of these organic compounds contained nitrogen indicating that organic nitrogen compounds formed during the combustion of biomass may be indicative of BB. Other compounds that showed negative correlations with δ13COC were possibly indicative of FF. These compounds included heavy hydrocarbons and were on the average less oxidized than the bulk organic carbon. The correlation of δ13COC and the O/C ratio was positive at low but negative at high desorption temperatures at the forest site. We propose that this might be due to

  13. High prevalence of enteric viruses in untreated individual drinking water sources and surface water in Slovenia.

    PubMed

    Steyer, Andrej; Torkar, Karmen Godič; Gutiérrez-Aguirre, Ion; Poljšak-Prijatelj, Mateja

    2011-09-01

    Waterborne infections have been shown to be important in outbreaks of gastroenteritis throughout the world. Although improved sanitary conditions are being progressively applied, fecal contaminations remain an emerging problem also in developed countries. The aim of our study was to investigate the prevalence of fecal contaminated water sources in Slovenia, including surface waters and groundwater sources throughout the country. In total, 152 water samples were investigated, of which 72 samples represents groundwater from individual wells, 17 samples from public collection supplies and 63 samples from surface stream waters. Two liters of untreated water samples were collected and concentrated by the adsorption/elution technique with positively charged filters followed by an additional ultracentrifugation step. Group A rotaviruses, noroviruses (genogroups I and II) and astroviruses were detected with real-time RT-PCR method in 69 (45.4%) out of 152 samples collected, of which 31/89 (34.8%) drinking water and 38/63 (60.3%) surface water samples were positive for at least one virus tested. In 30.3% of drinking water samples group A rotaviruses were detected (27/89), followed by noroviruses GI (2.2%; 2/89) and astroviruses (2.2%; 2/89). In drinking groundwater samples group A rotaviruses were detected in 27 out of 72 tested samples (37.5%), genogroup I noroviruses in two (2.8%), and human astroviruses in one (1.4%) samples. In surface water samples norovirus genogroup GII was the most frequently detected (41.3%; 26/63), followed by norovirus GI (33.3%; 21/63), human astrovirus (27.0%; 17/63) and group A rotavirus (17.5%; 11/63). Our study demonstrates relatively high percentage of groundwater contamination in Slovenia and, suggests that raw groundwater used as individual drinking water supply may constitute a possible source of enteric virus infections. In the future, testing for enteric viruses should be applied for drinking water sources in waterborne outbreaks

  14. Sweep-free brillouin optical time domain analysis using two individual laser sources

    NASA Astrophysics Data System (ADS)

    Tsuji, Kenichiro; Noda, Hitoshi; Onodera, Noriaki

    2012-11-01

    We propose a sweep-free measurement technique for distributed Brillouin frequency shift in optical fibers applicable to distributed strain/temperature monitoring systems, using two sets of pump-probe lights generated by two individual laser sources. This technique utilizes the Brillouin gain ratio measured at both the upper and lower side slopes of two different Brillouin spectra induced by two pump lights with different wavelengths. The proposed method offers high-speed measurement due to the combination of the frequency-sweep-free operation and the polarization-insensitive measurement scheme without polarization scramblers. A measurement accuracy of 17.3 μ ɛ with a spatial resolution of 5m over 2.6 km sensing length and a capability of kHz sampling rate are experimentally demonstrated.

  15. Source apportionment of fine and coarse particles at a roadside and urban background site in London during the 2012 summer ClearfLo campaign.

    PubMed

    Crilley, Leigh R; Lucarelli, Franco; Bloss, William J; Harrison, Roy M; Beddows, David C; Calzolai, Giulia; Nava, Silvia; Valli, Gianluigi; Bernardoni, Vera; Vecchi, Roberta

    2017-01-01

    London, like many major cities, has a noted air pollution problem, and a better understanding of the sources of airborne particles in the different size fractions will facilitate the implementation and effectiveness of control strategies to reduce air pollution. Thus, the trace elemental composition of the fine and coarse fraction were analysed at hourly time resolution at urban background (North Kensington, NK) and roadside (Marylebone Road, MR) sites within central London. Unlike previous work, the current study focuses on measurements during the summer providing a snapshot of contributing sources, utilising the high time resolution to improve source identification. Roadside enrichment was observed for a large number of elements associated with traffic emissions (Al, S, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Rb and Zr), while those elements that are typically from more regional sources (e.g. Na, Cl, S and K) were not found to have an appreciable increment. Positive Matrix Factorization (PMF) was applied for the source apportionment of the particle mass at both sites with similar sources being identified, including sea salt, airborne soil, traffic emissions, secondary inorganic aerosols and a Zn-Pb source. In the fine fraction, traffic emissions was the largest contributing source at MR (31.9%), whereas it was incorporated within an "urban background" source at NK, which had contributions from wood smoke, vehicle emissions and secondary particles. Regional sources were the major contributors to the coarse fraction at both sites. Secondary inorganic aerosols (which contained influences from shipping emissions and coal combustion) source factors accounted for around 33% of the PM10 at NK and were found to have the highest contributions from regional sources, including from the European mainland. Exhaust and non-exhaust sources both contribute appreciably to PM10 levels at the MR site, highlighting the continuing importance of vehicle-related air pollutants at

  16. On background radiation gradients--the use of airborne surveys when searching for orphan sources using mobile gamma-ray spectrometry.

    PubMed

    Kock, Peder; Rääf, Christopher; Samuelsson, Christer

    2014-02-01

    Systematic background radiation variations can lead to both false positives and failures to detect an orphan source when searching using car-borne mobile gamma-ray spectrometry. The stochastic variation at each point is well described by Poisson statistics, but when moving in a background radiation gradient the mean count rate will continually change, leading to inaccurate background estimations. Airborne gamma spectrometry (AGS) surveys conducted on the national level, usually in connection to mineral exploration, exist in many countries. These data hold information about the background radiation gradients which could be used at the ground level. This article describes a method that aims to incorporate the systematic as well as stochastic variations of the background radiation. We introduce a weighted moving average where the weights are calculated from existing AGS data, supplied by the Geological Survey of Sweden. To test the method we chose an area with strong background gradients, especially in the thorium component. Within the area we identified two roads which pass through the high-variability locations. The proposed method is compared with an unweighted moving average. The results show that the weighting reduces the excess false positives in the positive background gradients without introducing an excess of failures to detect a source during passage in negative gradients.

  17. Classification of Single Normal and Alzheimer's Disease Individuals from Cortical Sources of Resting State EEG Rhythms.

    PubMed

    Babiloni, Claudio; Triggiani, Antonio I; Lizio, Roberta; Cordone, Susanna; Tattoli, Giacomo; Bevilacqua, Vitoantonio; Soricelli, Andrea; Ferri, Raffaele; Nobili, Flavio; Gesualdo, Loreto; Millán-Calenti, José C; Buján, Ana; Tortelli, Rosanna; Cardinali, Valentina; Barulli, Maria Rosaria; Giannini, Antonio; Spagnolo, Pantaleo; Armenise, Silvia; Buenza, Grazia; Scianatico, Gaetano; Logroscino, Giancarlo; Frisoni, Giovanni B; Del Percio, Claudio

    2016-01-01

    Previous studies have shown abnormal power and functional connectivity of resting state electroencephalographic (EEG) rhythms in groups of Alzheimer's disease (AD) compared to healthy elderly (Nold) subjects. Here we tested the best classification rate of 120 AD patients and 100 matched Nold subjects using EEG markers based on cortical sources of power and functional connectivity of these rhythms. EEG data were recorded during resting state eyes-closed condition. Exact low-resolution brain electromagnetic tomography (eLORETA) estimated the power and functional connectivity of cortical sources in frontal, central, parietal, occipital, temporal, and limbic regions. Delta (2-4 Hz), theta (4-8 Hz), alpha 1 (8-10.5 Hz), alpha 2 (10.5-13 Hz), beta 1 (13-20 Hz), beta 2 (20-30 Hz), and gamma (30-40 Hz) were the frequency bands of interest. The classification rates of interest were those with an area under the receiver operating characteristic curve (AUROC) higher than 0.7 as a threshold for a moderate classification rate (i.e., 70%). Results showed that the following EEG markers overcame this threshold: (i) central, parietal, occipital, temporal, and limbic delta/alpha 1 current density; (ii) central, parietal, occipital temporal, and limbic delta/alpha 2 current density; (iii) frontal theta/alpha 1 current density; (iv) occipital delta/alpha 1 inter-hemispherical connectivity; (v) occipital-temporal theta/alpha 1 right and left intra-hemispherical connectivity; and (vi) parietal-limbic alpha 1 right intra-hemispherical connectivity. Occipital delta/alpha 1 current density showed the best classification rate (sensitivity of 73.3%, specificity of 78%, accuracy of 75.5%, and AUROC of 82%). These results suggest that EEG source markers can classify Nold and AD individuals with a moderate classification rate higher than 80%.

  18. Classification of Single Normal and Alzheimer's Disease Individuals from Cortical Sources of Resting State EEG Rhythms

    PubMed Central

    Babiloni, Claudio; Triggiani, Antonio I.; Lizio, Roberta; Cordone, Susanna; Tattoli, Giacomo; Bevilacqua, Vitoantonio; Soricelli, Andrea; Ferri, Raffaele; Nobili, Flavio; Gesualdo, Loreto; Millán-Calenti, José C.; Buján, Ana; Tortelli, Rosanna; Cardinali, Valentina; Barulli, Maria Rosaria; Giannini, Antonio; Spagnolo, Pantaleo; Armenise, Silvia; Buenza, Grazia; Scianatico, Gaetano; Logroscino, Giancarlo; Frisoni, Giovanni B.; del Percio, Claudio

    2016-01-01

    Previous studies have shown abnormal power and functional connectivity of resting state electroencephalographic (EEG) rhythms in groups of Alzheimer's disease (AD) compared to healthy elderly (Nold) subjects. Here we tested the best classification rate of 120 AD patients and 100 matched Nold subjects using EEG markers based on cortical sources of power and functional connectivity of these rhythms. EEG data were recorded during resting state eyes-closed condition. Exact low-resolution brain electromagnetic tomography (eLORETA) estimated the power and functional connectivity of cortical sources in frontal, central, parietal, occipital, temporal, and limbic regions. Delta (2–4 Hz), theta (4–8 Hz), alpha 1 (8–10.5 Hz), alpha 2 (10.5–13 Hz), beta 1 (13–20 Hz), beta 2 (20–30 Hz), and gamma (30–40 Hz) were the frequency bands of interest. The classification rates of interest were those with an area under the receiver operating characteristic curve (AUROC) higher than 0.7 as a threshold for a moderate classification rate (i.e., 70%). Results showed that the following EEG markers overcame this threshold: (i) central, parietal, occipital, temporal, and limbic delta/alpha 1 current density; (ii) central, parietal, occipital temporal, and limbic delta/alpha 2 current density; (iii) frontal theta/alpha 1 current density; (iv) occipital delta/alpha 1 inter-hemispherical connectivity; (v) occipital-temporal theta/alpha 1 right and left intra-hemispherical connectivity; and (vi) parietal-limbic alpha 1 right intra-hemispherical connectivity. Occipital delta/alpha 1 current density showed the best classification rate (sensitivity of 73.3%, specificity of 78%, accuracy of 75.5%, and AUROC of 82%). These results suggest that EEG source markers can classify Nold and AD individuals with a moderate classification rate higher than 80%. PMID:26941594

  19. Source and mixing state of iron-containing particles in Shanghai by individual particle analysis.

    PubMed

    Zhang, Guohua; Bi, Xinhui; Lou, Shengrong; Li, Lei; Wang, Hongli; Wang, Xinming; Zhou, Zhen; Sheng, Guoying; Fu, Jiamo; Chen, Changhong

    2014-01-01

    Bioavailable iron (Fe) is an essential nutrient that can control oceanic productivity, thereby impacting the global carbon budget and climate. Therefore it is of vital importance to identify chemical species and mixing state of Fe-containing particles in the air, which are demonstrated to pose substantial impact on bioavailability of Fe. Using a single particle aerosol mass spectrometer (SPAMS), ~2,000,000 individual particles with mass spectra were collected in Shanghai for nearly 22d during the winter of 2011. Number fraction of Fe-containing particles (NfFe) varied in a wide range (<1-15%) throughout the measurement. Fe-containing particles were mainly clustered into four chemical groups, comprising of Fe-rich, K-rich, Dust and V-containing particle types. Analysis of mass spectra and mixing state suggests that Fe-containing particles correspond to various sources in Shanghai, especially anthropogenic sources iron/steel industrial activities, and fly ashes from both biomass burning and coal combustion, accounting for ~55% and ~18%, respectively. However, invasion of dust from northern desert areas is suspected to be more responsible for the spikes of NfFe (>10%), when Dust particle type contributed to >50% of Fe-containing particles. It is also revealed that Fe-containing particles were internally mixed with secondary species (e.g., sulfate and nitrate). Anthropogenic K-rich and Fe-rich particles tended to associate with both sulfate and nitrate, and thus might lead to more fraction of soluble Fe, compared to Dust particles. These results imply that atmospheric processing of Fe-containing particles from various sources might vary and thus would change the bioavailability of atmospheric Fe.

  20. Sleep-disordered breathing in Hispanic/Latino individuals of diverse backgrounds. The Hispanic Community Health Study/Study of Latinos.

    PubMed

    Redline, Susan; Sotres-Alvarez, Daniela; Loredo, Jose; Hall, Martica; Patel, Sanjay R; Ramos, Alberto; Shah, Neomi; Ries, Andrew; Arens, Raanan; Barnhart, Janice; Youngblood, Marston; Zee, Phyllis; Daviglus, Martha L

    2014-02-01

    Hispanic/Latino populations have a high prevalence of cardiovascular risk factors and may be at risk for sleep-disordered breathing (SDB). An understanding of SDB among these populations is needed given evidence that SDB increases cardiovascular risk. To quantify SDB prevalence in the U.S. Hispanic/Latino population and its association with symptoms, risk factors, diabetes, and hypertension; and to explore variation by sex and Hispanic/Latino background. Cross-sectional analysis from the baseline examination of the Hispanic Community Health Study/Study of Latinos. The apnea-hypopnea index (AHI) was derived from standardized sleep tests; diabetes and hypertension were based on measurement and history. The sample of 14,440 individuals had an age-adjusted prevalence of minimal SDB (AHI ≥ 5), moderate SDB (AHI ≥ 15), and severe SDB (AHI ≥ 30) of 25.8, 9.8, and 3.9%, respectively. Only 1.3% of participants reported a sleep apnea diagnosis. Moderate SDB was associated with being male (adjusted odds ratio, 2.7; 95% confidence interval, 2.3-3.1), obese (16.8; 11.6-24.4), and older. SDB was associated with an increased adjusted odds of impaired glucose tolerance (1.7; 1.3-2.1), diabetes (2.3; 1.8-2.9), and hypertension. The association with hypertension varied across background groups with the strongest associations among individuals of Puerto Rican and Central American background. SDB is prevalent in U.S. Latinos but rarely associated with a clinical diagnosis. Associations with diabetes and hypertension suggest a large burden of disease may be attributed to untreated SDB, supporting the development and evaluation of culturally relevant detection and treatment approaches.

  1. Non-methane hydrocarbons in the atmosphere of a Metropolitan City and a background site in South Korea: Sources and health risk potentials

    NASA Astrophysics Data System (ADS)

    Choi, Eunhwa; Choi, Kyungho; Yi, Seung-Muk

    2011-12-01

    Hourly concentrations of non-methane hydrocarbons (NMHCs) were collected at a background monitoring site between April of 2004 and March of 2005 and at suburban and urban sites between March and December of 2006. The sources of NMHCs were identified and associated health risks through the inhalation pathway were evaluated. Positive matrix factorization (PMF) results showed that solvent sources account for the largest portion of the total NMHCs at suburban and urban areas in South Korea, and the risk assessment combined with the PMF results indicated that risk-weighted contributions of solvent sources were enhanced compared to the absolute contribution (from 52% to 68% in suburban areas and from 47% to 80% in urban areas). Carcinogenic risk due to benzene exposure exceeded the one-in-a-million (i.e., 10 -6) cancer benchmark at all three study sites, and the fractions of the population with greater than the benchmark level were 87%, 99%, and 98% in the background, suburban, and urban sites, respectively. Common benzene sources of three study sites were predicted to be Shandong in China based on the 120 h potential source contribution function (PSCF) analysis. To prioritize management options for NMHC sources, risk term may give more meaningful information than amount term. This study suggests that controlling solvent sources would be better option for the mitigation of non-carcinogenic health risk from airborne NMHCs. In addition, the identification of benzene sources using PSCF can be used to assist policymakers in developing regional measures to reduce benzene.

  2. EFFECTS OF DIFFUSE BACKGROUND EMISSION AND SOURCE CROWDING ON PHOTOMETRIC COMPLETENESS IN SPITZER SPACE TELESCOPE IRAC SURVEYS: THE GLIMPSE CATALOGS AND ARCHIVES

    SciTech Connect

    Kobulnicky, Henry A.; Alexander, Michael J.; Babler, Brian L.; Meade, Marilyn R.; Whitney, Barbara A.; Churchwell, Edward B. E-mail: malexan9@uwyo.edu E-mail: meade@astro.wisc.edu E-mail: ebc@astro.wisc.edu

    2013-07-01

    We characterize the completeness of point source lists from Spitzer Space Telescope surveys in the four Infrared Array Camera (IRAC) bandpasses, emphasizing the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) programs (GLIMPSE I, II, 3D, 360; Deep GLIMPSE) and their resulting point source Catalogs and Archives. The analysis separately addresses effects of incompleteness resulting from high diffuse background emission and incompleteness resulting from point source confusion (i.e., crowding). An artificial star addition and extraction analysis demonstrates that completeness is strongly dependent on local background brightness and structure, with high-surface-brightness regions suffering up to five magnitudes of reduced sensitivity to point sources. This effect is most pronounced at the IRAC 5.8 and 8.0 {mu}m bands where UV-excited polycyclic aromatic hydrocarbon emission produces bright, complex structures (photodissociation regions). With regard to diffuse background effects, we provide the completeness as a function of stellar magnitude and diffuse background level in graphical and tabular formats. These data are suitable for estimating completeness in the low-source-density limit in any of the four IRAC bands in GLIMPSE Catalogs and Archives and some other Spitzer IRAC programs that employ similar observational strategies and are processed by the GLIMPSE pipeline. By performing the same analysis on smoothed images we show that the point source incompleteness is primarily a consequence of structure in the diffuse background emission rather than photon noise. With regard to source confusion in the high-source-density regions of the Galactic Plane, we provide figures illustrating the 90% completeness levels as a function of point source density at each band. We caution that completeness of the GLIMPSE 360/Deep GLIMPSE Catalogs is suppressed relative to the corresponding Archives as a consequence of rejecting stars that lie in the point

  3. Expert and crowd-sourced validation of an individualized sleep spindle detection method employing complex demodulation and individualized normalization

    PubMed Central

    Ray, Laura B.; Sockeel, Stéphane; Soon, Melissa; Bore, Arnaud; Myhr, Ayako; Stojanoski, Bobby; Cusack, Rhodri; Owen, Adrian M.; Doyon, Julien; Fogel, Stuart M.

    2015-01-01

    A spindle detection method was developed that: (1) extracts the signal of interest (i.e., spindle-related phasic changes in sigma) relative to ongoing “background” sigma activity using complex demodulation, (2) accounts for variations of spindle characteristics across the night, scalp derivations and between individuals, and (3) employs a minimum number of sometimes arbitrary, user-defined parameters. Complex demodulation was used to extract instantaneous power in the spindle band. To account for intra- and inter-individual differences, the signal was z-score transformed using a 60 s sliding window, per channel, over the course of the recording. Spindle events were detected with a z-score threshold corresponding to a low probability (e.g., 99th percentile). Spindle characteristics, such as amplitude, duration and oscillatory frequency, were derived for each individual spindle following detection, which permits spindles to be subsequently and flexibly categorized as slow or fast spindles from a single detection pass. Spindles were automatically detected in 15 young healthy subjects. Two experts manually identified spindles from C3 during Stage 2 sleep, from each recording; one employing conventional guidelines, and the other, identifying spindles with the aid of a sigma (11–16 Hz) filtered channel. These spindles were then compared between raters and to the automated detection to identify the presence of true positives, true negatives, false positives and false negatives. This method of automated spindle detection resolves or avoids many of the limitations that complicate automated spindle detection, and performs well compared to a group of non-experts, and importantly, has good external validity with respect to the extant literature in terms of the characteristics of automatically detected spindles. PMID:26441604

  4. The PM2.5 chemical composition in an industrial zone included in a large urban settlement: main sources and local background.

    PubMed

    Squizzato, Stefania; Masiol, Mauro; Visin, Flavia; Canal, Andrea; Rampazzo, Giancarlo; Pavoni, Bruno

    2014-08-01

    Chemical analyses, receptor modeling and meteorological data were combined to determine the composition and sources of PM2.5 sampled daily in a large area in Italy characterized by a high number of heterogeneous industrial emissions and contiguous to a major urban center. The PM2.5 local background in the area, i.e. the common basic composition and concentrations of PM2.5, was determined. Factor analysis-multiple linear regression analysis (FA-MLRA) was used to identify and quantify the main PM sources. Groups of samples with similar source contributions were then sorted using cluster analysis. The potential source location and the influence of long range transport were investigated by using the conditional probability function (CPF) and the potential source contribution function (PSCF) respectively. On an annual basis, five sources of PM were found relevant. Industrial emissions accounted for 3% of PM mass, whereas the main contribution to PM was related to a combination of ammonium nitrate, combustion (54%) and road traffic (36%), mainly related to urban emissions. The PM2.5 background was estimated to account for 20 μg m(-3). It comprises contributions of 55% ammonium nitrate and combustion, 46% road traffic, 6% fossil fuel combustion and 3% industrial emissions. Source contributions are influenced by both local atmospheric circulation and regional transport.

  5. Variation in background intensity affects PET-based gross tumor volume delineation in non-small-cell lung cancer: the need for individualized information.

    PubMed

    Chen, Guan-hao; Yao, Zhi-feng; Fan, Xing-wen; Zhang, Ying-jian; Gao, Hui-quan; Qian, Wei; Wu, Kai-liang; Jiang, Guo-liang

    2013-10-01

    Efficient tumor volume delineation by the combined use of PET/CT scanning is necessary for the proper treatment of non-small cell lung cancer (NSCLC). To understand the effect of variation in background intensity on PET-based gross tumor volume (GTV) delineation, we determined the background standard uptake values (SUVs) in normal lung, aorta (blood pool), and liver tissues and determined GTVs using different methods. Thirty-seven previously untreated patients with pathologically confirmed NSCLC underwent PET/CT scanning with (18)F-fluorodeoxyglucose ((18)F-FDG). To obtain (18)F-FDG uptake values in normal tissues, regions of interest in the lung lobes (left upper, left lower, right upper, right middle, and right lower), aorta, and liver zones (left, intermediate, and right) were measured. The coefficient of variation (CV) of the SUV was measured for each normal structure. The CT-based GTV (GTV(CT)) was considered as the standard to which all PET-based GTVs were compared, and the correlation coefficient was analyzed to compare GTV obtained by the various delineation methods. Linear and logarithmic regression analyses were used to determine the relationship between GTV(CT) and GTV(PET). Normal lung tissue showed a significantly lower SUV and less stability than tissue of the aorta or liver. For the lung, aorta, and liver, the maximum SUV (SUV(max)) was 0.82 ± 0.32, 2.35 ± 0.37, and 3.24 ± 0.50 (CV: 38.79%, 15.82%, and 15.30%) and average SUV (SUV(ave)) was 0.49 ± 0.18, 1.68 ± 0.32, and 2.34 ± 0.36 (CV: 36.38%, 18.92%, and 15.44%), respectively. The SUVs of the lung varied from lobe to lobe. The GTV delineation method using the SUV(ave) of the lung lobe in which the tumor was found as background in the source-to-background ratio (SBR) method showed the best correlation with the volume of CT-based GTV (r=0.81). Our results show vast variation in the SUV among normal tissues, as well as in the different lung lobes. The tumor volume delineated using the SBR method

  6. Prevalence of Major Cardiovascular Risk Factors and Cardiovascular Diseases Among Hispanic/Latino Individuals of Diverse Backgrounds in the United States

    PubMed Central

    Daviglus, Martha L.; Talavera, Gregory A.; Avilés-Santa, M. Larissa; Allison, Matthew; Cai, Jianwen; Criqui, Michael H.; Gellman, Marc; Giachello, Aida L.; Gouskova, Natalia; Kaplan, Robert C.; LaVange, Lisa; Penedo, Frank; Perreira, Krista; Pirzada, Amber; Schneiderman, Neil; Wassertheil-Smoller, Sylvia; Sorlie, Paul D.; Stamler, Jeremiah

    2013-01-01

    Context Major cardiovascular diseases (CVDs) are leading causes of mortality among US Hispanic and Latino individuals. Comprehensive data are limited regarding the prevalence of CVD risk factors in this population and relations of these traits to socioeconomic status (SES) and acculturation. Objectives To describe prevalence of major CVD risk factors and CVD (coronary heart disease [CHD] and stroke) among US Hispanic/Latino individuals of different backgrounds, examine relationships of SES and acculturation with CVD risk profiles and CVD, and assess cross-sectional associations of CVD risk factors with CVD. Design, Setting, and Participants Multicenter, prospective, population-based Hispanic Community Health Study/Study of Latinos including individuals of Cuban (n =2201), Dominican (n = 1400), Mexican (n=6232), Puerto Rican (n=2590), Central American (n=1634), and South American backgrounds (n = 1022) aged 18 to 74 years. Analyses involved 15 079 participants with complete data enrolled between March 2008 and June 2011. Main Outcome Measures Adverse CVD risk factors defined using national guidelines for hypercholesterolemia, hypertension, obesity, diabetes, and smoking. Prevalence of CHD and stroke were ascertained from self-reported data. Results Age-standardized prevalence of CVD risk factors varied by Hispanic/Latino background; obesity and current smoking rates were highest among Puerto Rican participants (for men, 40.9% and 34.7%; for women, 51.4% and 31.7%, respectively); hypercholesterolemia prevalence was highest among Central American men (54.9%) and Puerto Rican women (41.0%). Large proportions of participants (80% of men, 71% of women) had at least 1 risk factor. Age- and sex-adjusted prevalence of 3 or more risk factors was highest in Puerto Rican participants (25.0%) and significantly higher (P<.001) among participants with less education (16.1%), those who were US-born (18.5%), those who had lived in the United States 10 years or longer (15.7%), and

  7. Year-round radiocarbon-based source apportionment of carbonaceous aerosols at two background sites in South Asia

    NASA Astrophysics Data System (ADS)

    Sheesley, Rebecca J.; Kirillova, Elena; Andersson, August; Krusâ, Martin; Praveen, P. S.; Budhavant, Krishnakant; Safai, P. D.; Rao, P. S. P.; Gustafsson, Örjan

    2012-05-01

    Atmospheric Brown Clouds (ABC), regional-scale haze events, are a significant concern for both human cardiopulmonary health and regional climate impacts. In order to effectively mitigate this pollution-based phenomenon, it is imperative to understand the magnitude, scope and source of ABC in regions such as South Asia. Two sites in S. Asia were chosen for a 15-month field campaign focused on isotope-based source apportionment of carbonaceous aerosols in 2008-2009. Both the Maldives Climate Observatory in Hanimaadhoo (MCOH) and a mountaintop site in Sinhagad, India (SINH) act as regionally mixed receptor sites. Annual radiocarbon-based source apportionment for soot elemental carbon (SEC) at MCOH and SINH revealed 73 ± 6% and 59 ± 5% contribution from biomass combustion, respectively (remainder from fossil fuel). The contributions from biogenic/biomass combustion to total organic carbon were similar between MCOH and SINH (69 ± 5% and 64 ± 5, respectively). The biomass combustion contribution for SEC in the current study, especially the results from MCOH, shows good agreement with published black carbon emissions inventories for India. Geographic source assessment, including clustered back trajectory analysis and carbon contribution by source region, indicated that the highest SEC/TOC loads originated from the W. Indian coastal margin, including the coastal city of Mumbai, India. The winter dry season 14C-based source apportionment of the BC-tracing SEC fraction for 2006, 2008, 2009 were not statistically different (p = 0.7) and point to a near-constant two-thirds contribution from biomass combustion practices, including wood and other biofuels as well as burning of agricultural crop residues.

  8. C5-C12 volatile organic compounds at roadside, residential, and background locations in Ankara, Turkey: temporal and spatial variations and sources.

    PubMed

    Kuntasal, Oznur Oğuz; Kilavuz, Seda Aslan; Karman, Deniz; Wang, Daniel; Tuncel, Gürdal

    2013-10-01

    Concentrations of 91 volatile organic compounds (VOCs) ranging from C5 to C12 were measured at three sites in Ankara, the capital of Turkey, in the summer of 2003 and winter of 2004. Samples were collected at roadside, residential and background stations at consecutive 4-hr intervals over a 24-hr period for six weeks in each season. Air samples were collected onto cartridges packed with Tenax TA and Carbopack B resins and analyzed by thermal desorption, followed by gas chromatography coupled to a mass selective detector (GC/MSD). Time resolved data provided information on ambient levels, temporal and spatial variations and sources of VOCs in Ankara. Toluene is the most abundant compound at all sites with and average concentration of 13.1 ?g m(-3). The mean concentrations of benzene are 12.6, 5.2, and 2.4 ?g m(-3) during winter at roadside, residential and background stations, respectively. Diurnal variation in the data together with toluene to benzene concentration ratio (T:B) that is close to 2.0 indicated the influence of traffic related emissions at residential and roadside stations during winter season. Higher T:B ratio observed at residential and background stations during summer period and correlation analysis indicated additional VOC sources. Temporal variations and low m,p-xylene to ethylbenzene ratio (mpX:E) indicated that transported air mass is the major VOC source influencing VOC concentrations measured at the background station.

  9. Identifying sediment sources and delivery mechanisms using background level polycyclic aromatic hydrocarbons in the Waiapu River watershed, New Zealand

    NASA Astrophysics Data System (ADS)

    Thompson, C. E.; Nichols, E. G.; Johnson, G.; Blair, N. E.; Leithold, E. L.; Palmer, A. S.; Baisden, W. T.

    2009-12-01

    The significant contribution of small mountainous river systems to the global fluvial sediment supply motivates investigation into the processes that influence the composition of the organic carbon that they carry. Organic matter preserved in continental margin sediments originates from terrestrial sources, such as kerogen and fresh and aged soil carbon, as well as marine sources. The identification of specific terrestrial fractions buried can facilitate interpretation of the organic geochemical record and enable reconstruction of watershed history. Carbon isotopic analyses have been used to apportion terrestrial carbon fractions preserved in marine environments; however, they have been generally limited to resolving modern C and kerogen. In this study, the use of polycyclic aromatic hydrocarbons (PAHs) to examine sediment production in the Waiapu watershed, New Zealand has been investigated. A suite of 42 alkylated and non-alkylated PAH concentrations establish chemical fingerprints for likely terrestrial sources of organic matter feeding the river and margin. Principal component analysis reveals chemical similarity between source and sink based on the degree of weathering and the relative inputs of petrogenic and pyrogenic PAHs. The primary sources of terrestrial organic matter buried over recent history on the continental shelf are Cretaceous bedrock, raw riverbank soils, and pastoral topsoils. Polytopic vector analysis of marine sediment establishes PAH end-member profiles, allowing sedimentary carbon on the shelf to be apportioned to contributing sources. These end-member model profiles confirm the PCA results, corresponding to PAH fingerprints of potential terrestrial sources including (1) bedrock composed of ancient kerogen, (2) soils from riverbank profiles that are composed of mixtures of ancient, aged, and modern carbon, and (3) topsoils typically composed of modern carbon from plant or fire-derived organic matter. Resolution of these sources suggests

  10. 14C-Based source assessment of soot aerosols in Stockholm and the Swedish EMEP-Aspvreten regional background site

    NASA Astrophysics Data System (ADS)

    Andersson, August; Sheesley, Rebecca J.; Kruså, Martin; Johansson, Christer; Gustafsson, Örjan

    2011-01-01

    Combustion-derived soot or black carbon (BC) in the atmosphere has a strong influence on both climate and human health. In order to propose effective mitigation strategies for BC emissions it is of importance to investigate geographical distributions and seasonal variations of BC emission sources. Here, a radiocarbon methodology is used to distinguish between fossil fuel and biomass burning sources of soot carbon (SC). SC is isolated for subsequent off-line 14C quantification with the chemothermal oxidation method at 375 °C (CTO-375 method), which reflects a recalcitrant portion of the BC continuum known to minimize inadvertent inclusion of any non-pyrogenic organic matter. Monitored wind directions largely excluded impact from the Stockholm metropolitan region at the EMEP-Aspvreten rural station 70 km to the south-west. Nevertheless, the Stockholm city and the rural stations yielded similar relative source contributions with fraction biomass ( fbiomass) for fall and winter periods in the range of one-third to half. Large temporal variations in 14C-based source apportionment was noted for both the 6 week fall and the 4 month winter observations. The fbiomass appeared to be related to the SC concentration suggesting that periods of elevated BC levels may be caused by increased wood fuel combustion. These results for the largest metropolitan area in Scandinavia combine with other recent 14C-based studies of combustion-derived aerosol fractions to suggest that biofuel combustion is contributing a large portion of the BC load to the northern European atmosphere.

  11. Individually Ventilated Cages Impose Cold Stress on Laboratory Mice: A Source of Systemic Experimental Variability

    PubMed Central

    David, John M; Knowles, Scott; Lamkin, Donald M; Stout, David B

    2013-01-01

    Individual ventilated cages (IVC) are increasing in popularity. Although mice avoid IVC in preference testing, they show no aversion when provided additional nesting material or the cage is not ventilated. Given the high ventilation rate in IVC, we developed 3 hypotheses: that mice housed in IVC experience more cold stress than do mice housed in static cages; that IVC-induced cold stress affects the results of experiments using mice; and that, when provided shelters, mice behaviorally thermoregulate and thereby rescue the cold-stress effects of IVC. To test these hypotheses, we housed mice in IVC, IVC with shelters, and static cages maintained at 20 to 21 °C. We quantified the cold stress of each housing system on mice by assessing nonshivering thermogenesis and brown adipose vacuolation. To test housing effects in a common, murine model of human disease, we implanted mice with subcutaneous epidermoid carcinoma cells and quantified tumor growth, tumor metabolism, and adrenal weight. Mice housed in IVC had histologic signs of cold stress and significantly higher nonshivering thermogenesis, smaller subcutaneous tumors, lower tumor metabolism, and larger adrenal weights than did mice in static cages. Shelters rescued IVC-induced nonshivering thermogenesis, adrenal enlargement, and phenotype-dependent cold-mediated histologic changes in brown adipose tissue and tumor size. IVC impose chronic cold stress on mice, alter experimental results, and are a source of systemic confounders throughout rodent-dependent research. Allowing mice to exhibit behavioral thermoregulation through seeking shelter markedly rescues the experiment-altering effects of housing-imposed cold stress, improves physiologic uniformity, and increases experimental reproducibility across housing systems. PMID:24351762

  12. Active Detection of Shielded Special Nuclear Material in the Presence of Variable High Backgrounds Using a Mixed Photon-Neutron Source

    NASA Astrophysics Data System (ADS)

    Martin, Philip N.; Clemett, Ceri D.; Hill, Cassie; O'Malley, John; Campbell, Ben

    This paper describes and compares two approaches to the analysis of active interrogation data containing high photon backgrounds associated with mixed photon-neutron source flash active interrogation. Results from liquid scintillation detectors (EJ301/EJ309) fielded at the Naval Research Laboratory (NRL), in collaboration with the Atomic Weapons Establishment (AWE), using the NRL Mercury Inductive Voltage Adder (IVA) operating in both a photon and mixed photon-neutron mode at a Depleted Uranium (DU) target are presented. The standard approach applying a Figure of Merit (FOM) consisting of background sigma above background is compared with an approach looking to fit only the time-decaying photon signal with standard delayed photon emission from ∼10-MeV end-point-energy Bremsstrahlung photofission of DU. Examples where each approach does well and less well are presented together with a discussion of the relative limitations of both approaches to the type of mixed photon-neutron flash active interrogation being considered.

  13. Bayesian nitrate source apportionment to individual groundwater wells in the Central Valley by use of elemental and isotopic tracers

    USGS Publications Warehouse

    Ransom, Katherine M; Grote, Mark N.; Deinhart, Amanda; Eppich, Gary; Kendall, Carol; Sanborn, Matthew E.; Sounders, A. Kate; Wimpenny, Joshua; Yin, Qing-zhu; Young, Megan B.; Harter, Thomas

    2016-01-01

    Groundwater quality is a concern in alluvial aquifers that underlie agricultural areas, such as in the San Joaquin Valley of California. Shallow domestic wells (less than 150 m deep) in agricultural areas are often contaminated by nitrate. Agricultural and rural nitrate sources include dairy manure, synthetic fertilizers, and septic waste. Knowledge of the relative proportion that each of these sources contributes to nitrate concentration in individual wells can aid future regulatory and land management decisions. We show that nitrogen and oxygen isotopes of nitrate, boron isotopes, and iodine concentrations are a useful, novel combination of groundwater tracers to differentiate between manure, fertilizers, septic waste, and natural sources of nitrate. Furthermore, in this work, we develop a new Bayesian mixing model in which these isotopic and elemental tracers were used to estimate the probability distribution of the fractional contributions of manure, fertilizers, septic waste, and natural sources to the nitrate concentration found in an individual well. The approach was applied to 56 nitrate-impacted private domestic wells located in the San Joaquin Valley. Model analysis found that some domestic wells were clearly dominated by the manure source and suggests evidence for majority contributions from either the septic or fertilizer source for other wells. But, predictions of fractional contributions for septic and fertilizer sources were often of similar magnitude, perhaps because modeled uncertainty about the fraction of each was large. For validation of the Bayesian model, fractional estimates were compared to surrounding land use and estimated source contributions were broadly consistent with nearby land use types.

  14. A method for environmental acoustic analysis improvement based on individual evaluation of common sources in urban areas.

    PubMed

    López-Pacheco, María G; Sánchez-Fernández, Luis P; Molina-Lozano, Herón

    2014-01-15

    Noise levels of common sources such as vehicles, whistles, sirens, car horns and crowd sounds are mixed in urban soundscapes. Nowadays, environmental acoustic analysis is performed based on mixture signals recorded by monitoring systems. These mixed signals make it difficult for individual analysis which is useful in taking actions to reduce and control environmental noise. This paper aims at separating, individually, the noise source from recorded mixtures in order to evaluate the noise level of each estimated source. A method based on blind deconvolution and blind source separation in the wavelet domain is proposed. This approach provides a basis to improve results obtained in monitoring and analysis of common noise sources in urban areas. The method validation is through experiments based on knowledge of the predominant noise sources in urban soundscapes. Actual recordings of common noise sources are used to acquire mixture signals using a microphone array in semi-controlled environments. The developed method has demonstrated great performance improvements in identification, analysis and evaluation of common urban sources. © 2013 Elsevier B.V. All rights reserved.

  15. Bayesian nitrate source apportionment to individual groundwater wells in the Central Valley by use of elemental and isotopic tracers

    NASA Astrophysics Data System (ADS)

    Ransom, Katherine M.; Grote, Mark N.; Deinhart, Amanda; Eppich, Gary; Kendall, Carol; Sanborn, Matthew E.; Souders, A. Kate; Wimpenny, Joshua; Yin, Qing-zhu; Young, Megan; Harter, Thomas

    2016-07-01

    Groundwater quality is a concern in alluvial aquifers that underlie agricultural areas, such as in the San Joaquin Valley of California. Shallow domestic wells (less than 150 m deep) in agricultural areas are often contaminated by nitrate. Agricultural and rural nitrate sources include dairy manure, synthetic fertilizers, and septic waste. Knowledge of the relative proportion that each of these sources contributes to nitrate concentration in individual wells can aid future regulatory and land management decisions. We show that nitrogen and oxygen isotopes of nitrate, boron isotopes, and iodine concentrations are a useful, novel combination of groundwater tracers to differentiate between manure, fertilizers, septic waste, and natural sources of nitrate. Furthermore, in this work, we develop a new Bayesian mixing model in which these isotopic and elemental tracers were used to estimate the probability distribution of the fractional contributions of manure, fertilizers, septic waste, and natural sources to the nitrate concentration found in an individual well. The approach was applied to 56 nitrate-impacted private domestic wells located in the San Joaquin Valley. Model analysis found that some domestic wells were clearly dominated by the manure source and suggests evidence for majority contributions from either the septic or fertilizer source for other wells. But, predictions of fractional contributions for septic and fertilizer sources were often of similar magnitude, perhaps because modeled uncertainty about the fraction of each was large. For validation of the Bayesian model, fractional estimates were compared to surrounding land use and estimated source contributions were broadly consistent with nearby land use types.

  16. Lung deposited surface area in Leicester urban background site/UK: Sources and contribution of new particle formation

    NASA Astrophysics Data System (ADS)

    Hama, Sarkawt M. L.; Ma, Nan; Cordell, Rebecca L.; Kos, Gerard P. A.; Wiedensohler, Alfred; Monks, Paul S.

    2017-02-01

    Lung Deposited Surface Area (LDSA) has been identified as a potential metric for the correlation of a physical aerosol particle properties with health outcomes. Currently, there is little urban LDSA data. As a case study, we investigated measurements of LDSA (alveolar) concentrations in a mid-size European city. LDSA and associated measurements were carried out over 1.5 years at an urban background site in Leicester, UK. Average LDSA concentrations in the cold (November-April) and warm (May-October) seasons of UK were 37 and 23 μm2 cm-3, respectively. LDSA correlates well (R2 = 0.65-0.7, r = 0.77-0.8) with traffic related pollutants, such as equivalent black carbon (eBC) and NOX. We also report for the first time in the UK the correlation between an empirically derived LDSA and eBC. Furthermore, the effect of wind speed and direction on the LDSA was explored. Higher LDSA concentrations are observed at low wind speeds (1-2 m s-1), owing to local traffic emissions. In addition, the diurnal variation of LDSA showed a second peak in the afternoon under warm and relatively clean atmospheric conditions, which can be attributed to photochemical new particle formation (NPF) and growth into the Aitken mode range. These NPF events increased the average background LDSA concentrations from 15.5 to 35.5 μm2 cm-3, although they might not be health-relevant. Overall, the results support the notion that local traffic emissions are a major contributor to observed LDSA concentrations with a clear seasonal pattern with higher values during winter.

  17. Comparison of sex-linked dwarf genes in chickens from two sources when introgressed into unrelated genetic backgrounds.

    PubMed

    Dunnington, E A; Siegel, P B

    1998-05-01

    1. Sex-linked dwarfing genes from 2 broiler stock origins (EU and US) were each introgressed into 2 White Leghorn populations that had been divergently selected for antibody response to sheep erythrocytes. 2. When the resulting backcrossed populations were 87.5% of their respective. White Leghorn line, non-dwarf pullets were assessed for body weights, shank lengths, immunoresponsiveness, age and body weight at sexual maturity, egg production, average egg weight, and duration of fertility. For measurements where there were no differences between non-dwarf pullets from the 2 origins of the dwarfing genes, then the dwarf pullets (which were full sisters to the non-dwarfs) were compared. 3. Shank length at 8 weeks of age and mature (24-week) body weights were higher for dwarf pullets from EU than US dwarf origin. Immune response and several egg production traits were higher for dwarf pullets from the high antibody backcross than from those of the low antibody backcross. 4. There were few differences in expression of the dwarfing genes from 2 origins in the unrelated backcross populations used in this study. Also each of the dwarfing genes, when introgressed into different genomic backgrounds, was not discernibly different in its expression in terms of antibody response or egg production characteristics.

  18. Identification of source velocities on 3D structures in non-anechoic environments: Theoretical background and experimental validation of the inverse patch transfer functions method

    NASA Astrophysics Data System (ADS)

    Aucejo, M.; Totaro, N.; Guyader, J.-L.

    2010-08-01

    In noise control, identification of the source velocity field remains a major problem open to investigation. Consequently, methods such as nearfield acoustical holography (NAH), principal source projection, the inverse frequency response function and hybrid NAH have been developed. However, these methods require free field conditions that are often difficult to achieve in practice. This article presents an alternative method known as inverse patch transfer functions, designed to identify source velocities and developed in the framework of the European SILENCE project. This method is based on the definition of a virtual cavity, the double measurement of the pressure and particle velocity fields on the aperture surfaces of this volume, divided into elementary areas called patches and the inversion of impedances matrices, numerically computed from a modal basis obtained by FEM. Theoretically, the method is applicable to sources with complex 3D geometries and measurements can be carried out in a non-anechoic environment even in the presence of other stationary sources outside the virtual cavity. In the present paper, the theoretical background of the iPTF method is described and the results (numerical and experimental) for a source with simple geometry (two baffled pistons driven in antiphase) are presented and discussed.

  19. Dynamic Systems for Individual Tracking via Heterogeneous Information Integration and Crowd Source Distributed Simulation

    DTIC Science & Technology

    2015-12-04

    Tracking the movement of individuals in complex urban environments using mobile sensors is a challenging, but important problem in applications such...collection and analysis of energy usage of distributed simulations. 6 1   DDDAS System Overview Tracking the movement of vehicles in...recognition, scene analysis, and trajectory detection and prediction. This project focused on tracking the movement of individuals traveling in vehicles

  20. Assessing the efficacy of candidate mosquito repellents against the background of an attractive source that mimics a human host.

    PubMed

    Menger, D J; Van Loon, J J A; Takken, W

    2014-12-01

    Mosquito repellents are used around the globe to protect against nuisance biting and disease-transmitting mosquitoes. Recently, there has been renewed interest in the development of repellents as tools to control the transmission of mosquito-borne diseases. We present a new bioassay for the accurate assessment of candidate repellent compounds, using a synthetic odour that mimics the odour blend released by human skin. Using DEET (N,N-diethyl-meta-toluamide) and PMD (p-menthane-3,8-diol) as reference compounds, nine candidate repellents were tested, of which five showed significant repellency to the malaria mosquito Anopheles gambiae sensu stricto (Diptera: Culicidae). These included: 2-nonanone; 6-methyl-5-hepten-2-one; linalool; δ-decalactone, and δ-undecalactone. The lactones were also tested on the yellow fever mosquito Aedes aegypti (Stegomyia aegypti) (Diptera: Culicidae), against which they showed similar degrees of repellency. We conclude that the lactones are highly promising repellents, particularly because these compounds are pleasant-smelling, natural products that are also present in human food sources. © 2014 The Royal Entomological Society.

  1. The Fermi -Lat High-Latitude Survey: Source Count Distributions And The Origin Of The Extragalactic Diffuse Background

    SciTech Connect

    Abdo, A. A.

    2010-08-11

    This is the first of a series of papers aimed at characterizing the populations detected in the high-latitude sky of the Fermi-LAT survey. In this work, we focus on the intrinsic spectral and flux properties of the source sample. We show that when selection effects are properly taken into account, Fermi sources are on average steeper than previously found (e.g., in the bright source list) with an average photon index of 2.40 ± 0.02 over the entire 0.1-100 GeV energy band. We confirm that flat spectrum radio quasars have steeper spectra than BL Lacertae objects with an average index of 2.48 ± 0.02 versus 2.18 ± 0.02. Using several methods, we build the deepest source count distribution at GeV energies, deriving that the intrinsic source (i.e., blazar) surface density at F 100 ≥ 10–9 ph cm–2 s–1 is 0.12+0.03 –0.02 deg–2. The integration of the source count distribution yields that point sources contribute 16(±1.8)% (±7% systematic uncertainty) of the GeV isotropic diffuse background. At the fluxes currently reached by LAT, we can rule out the hypothesis that pointlike sources (i.e., blazars) produce a larger fraction of the diffuse emission.

  2. A spatial individual-based model predicting a great impact of copious sugar sources and resting sites on survival of Anopheles gambiae and malaria parasite transmission

    USGS Publications Warehouse

    Zhu, Lin; Qualls, Whitney A.; Marshall, John M; Arheart, Kris L.; DeAngelis, Don; McManus, John W.; Traore, Sekou F.; Doumbia, Seydou; Schlein, Yosef; Muller, Gunter C.; Beier, John C.

    2015-01-01

    BackgroundAgent-based modelling (ABM) has been used to simulate mosquito life cycles and to evaluate vector control applications. However, most models lack sugar-feeding and resting behaviours or are based on mathematical equations lacking individual level randomness and spatial components of mosquito life. Here, a spatial individual-based model (IBM) incorporating sugar-feeding and resting behaviours of the malaria vector Anopheles gambiae was developed to estimate the impact of environmental sugar sources and resting sites on survival and biting behaviour.MethodsA spatial IBM containing An. gambiae mosquitoes and humans, as well as the village environment of houses, sugar sources, resting sites and larval habitat sites was developed. Anopheles gambiae behaviour rules were attributed at each step of the IBM: resting, host seeking, sugar feeding and breeding. Each step represented one second of time, and each simulation was set to run for 60 days and repeated 50 times. Scenarios of different densities and spatial distributions of sugar sources and outdoor resting sites were simulated and compared.ResultsWhen the number of natural sugar sources was increased from 0 to 100 while the number of resting sites was held constant, mean daily survival rate increased from 2.5% to 85.1% for males and from 2.5% to 94.5% for females, mean human biting rate increased from 0 to 0.94 bites per human per day, and mean daily abundance increased from 1 to 477 for males and from 1 to 1,428 for females. When the number of outdoor resting sites was increased from 0 to 50 while the number of sugar sources was held constant, mean daily survival rate increased from 77.3% to 84.3% for males and from 86.7% to 93.9% for females, mean human biting rate increased from 0 to 0.52 bites per human per day, and mean daily abundance increased from 62 to 349 for males and from 257 to 1120 for females. All increases were significant (P < 0.01). Survival was greater when sugar sources were randomly

  3. Studies on geological background and source of fluorine in drinking water in the North China Plate fluorosis areas

    USGS Publications Warehouse

    Luo, K.; Feng, F.; Li, H.; Chou, C.-L.; Feng, Z.; Yunshe, D.

    2008-01-01

    Endemic fluorosis in northern China is usually produced by high fluorine (F) content in drinking water. Thirty-one samples of drinking waters, mainly well waters and nearly 200 samples of rocks, loess, and coal were analyzed for F content using the combustion hydrolysis-fluoride-ion selective electrode (ISE) method. The geologic cross sections of two well-known fluorosis basins were studied. The solubility of F in different rock types collected from fluorosis areas was determined. Results showed that areas of endemic fluorosis in northern China are located in coal-bearing basins which are comprised of three stratagraphic portions. The lowest portion is Precambrian granitic rocks or Cambrian-Ordovician carbonates. The middle portion consists of Permo-Carboniferous or Jurassic coal-bearing sequences. The upper portion is 0-400 m Pleistocene loess. Flourine content in the Precambrian granite-gneiss contained (a) 1090-1460 ppm, in the Cambrian-Ordovician limestone and dolomite, (b) 52-133 ppm, in black shales and coal gob of Permo-Carboniferous coal-bearing strata, (c) 200-700 ppm, and (d) Pleistocene loess 454-542 ppm. The solubility of F in black shales of coal-bearing sequences was higher than in Precambrian granitic rocks, and both were more soluble than loess. F solubility from Precambrian granitic rocks was moderate, but Precambrian granitic rocks have high F content and thus contribute an appreciable amount of ion to the shallow groundwater (well water). Varying F content in shallow groundwater is controlled by geological conditions. The sources of F in the shallow groundwater from fluorosis areas in northern China are mainly derived from black shales of coal-bearing sequences and Precambrian granitic basement in the basins of northern China. ?? 2008 Taylor & Francis.

  4. Better constraints on sources of carbonaceous aerosols using a combined 14C - macro tracer analysis in a European rural background site

    NASA Astrophysics Data System (ADS)

    Gilardoni, S.; Vignati, E.; Cavalli, F.; Putaud, J. P.; Larsen, B. R.; Karl, M.; Stenström, K.; Genberg, J.; Henne, S.; Dentener, F.

    2011-06-01

    The source contributions to carbonaceous PM2.5 aerosol were investigated at a European background site at the edge of the Po Valley, in Northern Italy, during the period January-December 2007. Carbonaceous aerosol was described as the sum of 8 source components: primary (1) and secondary (2) biomass burning organic carbon, biomass burning elemental carbon (3), primary (4) and secondary (5) fossil organic carbon, fossil fuel burning elemental carbon (6), primary (7) and secondary (8) biogenic organic carbon. The mass concentration of each component was quantified using a set of macro tracers (organic carbon OC, elemental carbon EC, and levoglucosan), micro tracers (arabitol and mannitol), and 14C measurements. This was the first time that 14C measurements covered a full annual cycle with daily resolution. This set of 6 tracers, together with assumed uncertainty ranges of the ratios of OC-to-EC, and the reference fraction of modern carbon in the 8 source categories, provides strong constraints to the source contributions to carbonaceous aerosol. The uncertainty of contributions was assessed with a Quasi-Monte Carlo (QMC) method accounting for the variability of OC and EC emission factors, the uncertainty of reference fractions of modern carbon, and the measurement uncertainty. During winter, biomass burning composed 64 % (±15 %) of the total carbon (TC) concentration, while in summer secondary biogenic OC accounted for 50 % (±16 %) of TC. The contribution of primary biogenic aerosol particles was negligible during the entire year. Moreover, aerosol associated with fossil sources represented 27 % (±16 %) and 41 % (±26 %) of TC in winter and summer, respectively. The contribution of secondary organic aerosol (SOA) to the organic mass (OM) was significant during the entire year. SOA accounted for 30 % (±16 %) and 85 % (±12 %) of OM during winter and summer, respectively. While the summer SOA was dominated by biogenic sources, winter SOA was mainly due to biomass

  5. Bayesian Nitrate Source Apportionment to Individual Groundwater Wells in the Central Valley by Use of Elemental and Isotopic Tracers

    NASA Astrophysics Data System (ADS)

    Ransom, K.; Grote, M. N.; Deinhart, A.; Eppich, G.; Kendall, C.; Sanborn, M.; Souders, K.; Wimpenny, J.; Yin, Q. Z.; Young, M. B.; Harter, T.

    2015-12-01

    Groundwater quality is a concern in alluvial aquifers that underlie agricultural areas, such as in the San Joaquin Valley of California. Nitrate from fertilizers and animal waste can leach to groundwater and contaminate drinking water resources. Dairy manure and synthetic fertilizers are prevailing sources of nitrate in groundwater for the San Joaquin Valley with septic waste contributing as a major source in some areas. The rural population in the San Joaquin Valley relies almost exclusively on shallow domestic wells (less than 150 m deep), of which many have been affected by nitrate. Knowledge of the proportion of each of the three main nitrate sources (manure, synthetic fertilizer, and septic waste) contributing to individual well nitrate can aid future regulatory decisions. Mixing models quantify the proportional contributions of sources to a mixture by using the concentration of conservative tracers within each source as a source signature. Deterministic mixing models are common, but do not allow for variability in the tracer source concentration or overlap of tracer concentrations between sources. In contrast, Bayesian mixing models treat source contributions probabilistically, building statistical variation into the inferences for each well. The authors developed a Bayesian mixing model on a pilot network of 56 private domestic wells in the San Joaquin Valley for which nitrogen, oxygen, and boron isotopes as well as nitrate and iodine were measured. Nitrogen, oxygen, and boron isotopes as well as iodine can be used as tracers to differentiate between manure, fertilizers, septic waste, and natural sources of nitrate (which can contribute nitrate in concentrations up to 4 mg/L). In this work, the isotopic and elemental tracers were used to estimate the proportional contribution of manure, fertilizers, septic waste, and natural sources to overall groundwater nitrate concentration in individual wells. Prior distributions for the four tracers for each of the four

  6. Atmospheric carbon tetrachloride in rural background and industry surrounded urban areas in Northern Iberian Peninsula: Mixing ratios, trends, and potential sources.

    PubMed

    de Blas, Maite; Uria-Tellaetxe, Iratxe; Gomez, Maria Carmen; Navazo, Marino; Alonso, Lucio; García, Jose Antonio; Durana, Nieves; Iza, Jon; Ramón, Jarol Derley

    2016-08-15

    Latest investigations on atmospheric carbon tetrachloride (CTC) are focused on its ozone depleting potential, adverse effects on the human health, and radiative efficiency and Global Warming Potential as a greenhouse gas. CTC mixing ratios have been thoroughly studied since its restriction under the Montreal Protocol, mostly in remote areas with the aim of reporting long-term trends after its banning. The observed decrease of the CTC background mixing ratio, however, was not as strong as expected. In order to explain this behavior CTC lifetime should be adjusted by estimating the relative significance of its sinks and by identifying ongoing potential sources. Looking for possible sources, CTC was measured with high-time resolution in two sites in Northern Spain, using auto-GC systems and specifically developed acquisition and processing methodologies. The first site, Bilbao, is an urban area influenced by the surrounding industry, where measurements were performed with GC-MSD for a one-year period (2007-2008). The second site, at Valderejo Natural Park (VNP), is a rural background area where measurements were carried out with GC-FID and covering CTC data a nonsuccessive five-year period (2003-2005, 2010-2011, and 2014-2015years). Median yearly CTC mixing ratios were slightly higher in the urban area (120pptv) than in VNP (80-100pptv). CTC was reported to be well mixed in the atmosphere and no sources were noticed to impact the rural site. The observed long-term trend in VNP was in agreement with the estimated global CTC emissions. In the urban site, apart from industrial and commercial CTC sources, chlorine-bleach products used as cleaning agents were reported as promotors of indoor sources.

  7. Combining Positive Matrix Factorization and Radiocarbon Measurements for Source Apportionment of PM2.5 from a National Background Site in North China.

    PubMed

    Wang, Xiaoping; Zong, Zheng; Tian, Chongguo; Chen, Yingjun; Luo, Chunling; Li, Jun; Zhang, Gan; Luo, Yongming

    2017-09-06

    To explore the utility of combining positive matrix factorization (PMF) with radiocarbon ((14)C) measurements for source apportionment, we applied PM2.5 data collected for 14 months at a national background station in North China to PMF models. The solutions were compared to (14)C results of four seasonally averaged samples and three outlier samples. Comparing the most readily interpretable PMF solutions and (14)C results revealed that PMF modeling was well able to capture the source patterns of PM2.5 with two and three irrelevant source classifications for the seasonal and outlier samples. The contribution of sources that could not be classified as either fossil or non-fossil sources in the PMF solution, and the errors between the modeled and measured concentrations weakened the effectiveness of the comparison. Based on these two factors, we developed an index for selecting the most suitable (14)C measurement samples for combining with the PMF model. Then we examined the potential for coupling PMF modeling and (14)C data with a constrained PMF run using the (14)C data as a priori information. The restricted run could provide a more reliable solution; however, the PMF model must provide a flexible dialog to input the priori restrictions for executing the constraint simulation.

  8. Investigating patients with an immigration background in Canada: relationships between individual immigrant attitudes, the doctor-patient relationship, and health outcomes.

    PubMed

    Whittal, Amanda; Lippke, Sonia

    2016-01-12

    Increasing immigration in the world today leads to more intercultural interactions. This is a particularly crucial fact in doctor-patient relationships, which often become more complex and suboptimal within an intercultural context. Since acculturation is a particularly important factor in this process, and the doctor-patient relationship is a key component in patient health outcomes, this study investigates the interrelation of individual immigrant acculturation orientations with the quality of the doctor-immigrant patient relationship, the patients' perceived quality of care, and how this relates to immigrant health behaviours and quality of life of the patients. 171 immigrant patients of various backgrounds participated in a paper and pencil questionnaire to assess the role of acculturation orientations (AO) on patients' perceived expectations of their doctor, perceived quality of care (PQOC), health behaviours and quality of life. Data were analyzed using ANOVA, regression and correlation procedures with SPSS statistical software. Significant correlations were found between all AOs and measures of the participant feeling connected to the host or home culture, thereby verifying the measure of AO. All four AOs were significantly interrelated directly with the patient's perception of what the doctor expects of him/her, and the patients' quality of life. Patients' perceived expectations of their doctors were significantly related to the patients' PQOC, and PQOC was associated with improved health behaviours (adherence to doctor recommendations, physical activity maintenance self-efficacy). AO may be an important factor in the doctor-immigrant patient relationship, via a complex process involving the patients' perceptions of doctors' expectations and perceived quality of care. This has important implications, since such an understanding can be used to create interventions for both doctors and immigrant patients to learn about their own AO, how it can relate to the

  9. Electrophysiological Correlates of Emotional Source Memory in High-Trait-Anxiety Individuals

    PubMed Central

    Cui, Lixia; Shi, Guangyuan; He, Fan; Zhang, Qin; Oei, Tian P. S.; Guo, Chunyan

    2016-01-01

    The interaction between recognition memory and emotion has become a research hotspot in recent years. Dual process theory posits that familiarity and recollection are two separate processes contributing to recognition memory, but further experimental evidence is needed. The present study explored the emotional context effects on successful and unsuccessful source retrieval amongst 15 high-trait-anxiety college students by using event-related potentials (ERPs) measurement. During study, a happy, fearful, or neutral face picture first was displayed, then a Chinese word was superimposed centrally on the picture and subjects were asked to remember the word and the corresponding type of picture. During the test participants were instructed to press one of four buttons to indicate whether the displayed word was an old or new word. And then, for the old word, indicate whether it had been shown with a fearful, happy, or neutral face during the study. ERPs were generally more positive for remembered words than for new words and the ERP difference was termed as an old/new effect. It was found that, for successful source retrieval (it meant both the item and the source were remembered accurately) between 500 and 700 ms (corresponding to a late positive component, LPC), there were significant old/new effects in all contexts. However, for unsuccessful source retrieval (it meant the correct recognition of old items matched with incorrect source attribution), there were no significant old/new effects in happy and neutral contexts, though significant old/new effects were observed in the fearful context. Between 700 and 1200 ms (corresponding to a late slow wave, LSW), there were significant old/new effects for successful source retrieval in happy and neutral contexts. However, in the fearful context, the old/new effects were reversed, ERPs were more negative for successful source retrieval compared to correct rejections. Moreover, there were significant emotion effects for

  10. Improved western U.S. background ozone estimates via constraining nonlocal and local source contributions using Aura TES and OMI observations

    NASA Astrophysics Data System (ADS)

    Huang, Min; Bowman, Kevin W.; Carmichael, Gregory R.; Lee, Meemong; Chai, Tianfeng; Spak, Scott N.; Henze, Daven K.; Darmenov, Anton S.; da Silva, Arlindo M.

    2015-04-01

    Western U.S. near-surface ozone (O3) concentrations are sensitive to transported background O3 from the eastern Pacific free troposphere, as well as U.S. anthropogenic and natural emissions. The current 75 ppbv U.S. O3 primary standard may be lowered soon, hence accurately estimating O3 source contributions, especially background O3 in this region has growing policy-relevant significance. In this study, we improve the modeled total and background O3, via repartitioning and redistributing the contributions from nonlocal and local anthropogenic/wildfires sources in a multi-scale satellite data assimilation system containing global Goddard Earth Observing System-Chemistry model (GEOS-Chem) and regional Sulfur Transport and dEposition Model (STEM). Focusing on NASA's ARCTAS (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites) field campaign period in June-July 2008, we first demonstrate that the negative biases in GEOS-Chem free simulation in the eastern Pacific at 400-900 hPa are reduced via assimilating Aura-Tropospheric Emission Spectrometer (TES) O3 profiles. Using the TES-constrained boundary conditions, we then assimilated into STEM the tropospheric nitrogen dioxide (NO2) columns from Aura-Ozone Monitoring Instrument to indicate U.S. nitrogen oxides (NOx = NO2 + NO) emissions at 12 × 12 km2 grid scale. Improved model skills are indicated from cross validation against independent ARCTAS measurements. Leveraging Aura observations, we show anomalously high wildfire NOx emissions in this summer in Northern California and the Central Valley while lower anthropogenic emissions in multiple urban areas than those representing the year of 2005. We found strong spatial variability of the daily maximum 8 h average background O3 and its contribution to the modeled total O3, with the mean value of 48 ppbv ( 77% of the total).

  11. Better constraints on sources of carbonaceous aerosols using a combined 14C - macro tracer analysis in a European rural background site

    NASA Astrophysics Data System (ADS)

    Gilardoni, S.; Vignati, E.; Cavalli, F.; Putaud, J. P.; Larsen, B. R.; Karl, M.; Stenström, K.; Genberg, J.; Henne, S.; Dentener, F.

    2011-01-01

    The source contributions to carbonaceous PM2.5 aerosol were investigated at a European background site at the edge of the Po Valley, in Northern Italy, during the period January-December 2007. Carbonaceous aerosol was described as the sum of eight source components: primary (1) and secondary (2) biomass burning organic carbon, biomass burning elemental carbon (3), primary (4) and secondary (5) fossil fuel burning organic carbon, fossil fuel burning elemental carbon (6), primary (7) and secondary (8) biogenic organic carbon. The concentration of each component was quantified using a set of macro tracers (organic carbon OC, elemental carbon EC, and levoglucosan), micro tracers (arabitol and mannitol), and 14C measurements. This was the first time that 14C measurements were performed on a long time series of data able to represent the entire annual cycle. This set of 6 tracers, together with assumed uncertainty ranges of the ratios of OC-to-EC, and the fraction of modern carbon in the 8 source categories, provides strong constraints to the source contributions to carbonaceous aerosol. The uncertainty of contributions was assessed with a Quasi-Monte Carlo (QMC) method accounting for the variability of OC and EC emission factors, and the uncertainty of reference fractions of modern carbon. During winter biomass burning composed 50% of the total carbon (TC) concentration, while in summer secondary biogenic OC accounted for 45% of TC. The contribution of primary biogenic aerosol particles was negligible during the entire year. Moreover, aerosol associated with fossil fuel burning represented 26% and 43% of TC in winter and summer, respectively. The comparison of source apportionment results in different urban and rural areas showed that the sampling site was mainly affected by local aerosol sources during winter and regional air masses from the nearby Po Valley in summer. This observation was further confirmed by back-trajectory analysis applying the Potential Source

  12. Individuals with low working memory spans show greater interference from irrelevant information because of poor source monitoring, not greater activation.

    PubMed

    Lilienthal, Lindsey; Rose, Nathan S; Tamez, Elaine; Myerson, Joel; Hale, Sandra

    2015-04-01

    Although individuals with high and low working memory (WM) span appear to differ in the extent to which irrelevant information interferes with their performance on WM tasks, the locus of this interference is not clear. The present study investigated whether, when performing a WM task, high- and low-span individuals differ in the activation of formerly relevant, but now irrelevant items, and/or in their ability to correctly identify such irrelevant items. This was done in two experiments, both of which used modified complex WM span tasks. In Experiment 1, the span task included an embedded lexical decision task designed to obtain an implicit measure of the activation of both currently and formerly relevant items. In Experiment 2, the span task included an embedded recognition judgment task designed to obtain an explicit measure of both item and source recognition ability. The results of these experiments indicate that low-span individuals do not hold irrelevant information in a more active state in memory than high-span individuals, but rather that low-span individuals are significantly poorer at identifying such information as irrelevant at the time of retrieval. These results suggest that differences in the ability to monitor the source of information, rather than differences in the activation of irrelevant information, are the more important determinant of performance on WM tasks.

  13. First results of a simultaneous measurement of tritium and 14C in an ultra-low-background proportional counter for environmental sources of methane

    SciTech Connect

    Mace, Emily K.; Aalseth, Craig E.; Day, Anthony R.; Hoppe, Eric W.; Keillor, Martin E.; Moran, James J.; Panisko, Mark E.; Seifert, Allen; Tatishvili, Gocha; Williams, Richard M.

    2016-02-01

    Abstract Simultaneous measurement of tritium and 14C would provide an added tool for tracing organic compounds through environmental systems and is possible via beta energy spectroscopy of sample-derived methane in internal-source gas proportional counters. Since the mid-1960’s atmospheric tritium and 14C have fallen dramatically as the isotopic injections from above-ground nuclear testing have been diluted into the ocean and biosphere. In this work, the feasibility of simultaneous tritium and 14C measurements via proportional counters is revisited in light of significant changes in both the atmospheric and biosphere isotopics and the development of new ultra-low-background gas proportional counting capabilities for small samples (roughly 50 cc methane). A Geant4 Monte Carlo model of a Pacific Northwest National Laboratory (PNNL) proportional counter response to tritium and 14C is used to analyze small samples of two different methane sources to illustrate the range of applicability of contemporary simultaneous measurements and their limitations. Because the two methane sources examined were not sample size limited, we could compare the small-sample measurements performed at PNNL with analysis of larger samples performed at a commercial laboratory. The dual-isotope simultaneous measurement is well matched for methane samples that are atmospheric or have an elevated source of tritium (i.e. landfill gas). For samples with low/modern tritium isotopics (rainwater), commercial separation and counting is a better fit.

  14. First results of a simultaneous measurement of tritium and (14)C in an ultra-low-background proportional counter for environmental sources of methane.

    PubMed

    Mace, E K; Aalseth, C E; Day, A R; Hoppe, E W; Keillor, M E; Moran, J J; Panisko, M E; Seifert, A; Tatishvili, G; Williams, R M

    2016-05-01

    Simultaneous measurement of tritium and (14)C would provide an added tool for tracing organic compounds through environmental systems and is possible via beta energy spectroscopy of sample-derived methane in internal-source gas proportional counters. Since the mid-1960's atmospheric tritium and (14)C have fallen dramatically as the isotopic injections from aboveground nuclear testing have been diluted into the ocean and biosphere. In this work, the feasibility of simultaneous tritium and (14)C measurements via proportional counters is revisited in light of significant changes in both the atmospheric and biosphere isotopics and the development of new ultra-low-background gas proportional counting capabilities for small samples (roughly 50 cc methane). A Geant4 Monte Carlo model of a Pacific Northwest National Laboratory (PNNL) proportional counter response to tritium and (14)C is used to analyze small samples of two different methane sources to illustrate the range of applicability of contemporary simultaneous measurements and their limitations. Because the two methane sources examined were not sample size limited, we could compare the small-sample measurements performed at PNNL with analysis of larger samples performed at a commercial laboratory. These first results show that the dual-isotope simultaneous measurement is well matched for methane samples that are atmospheric or have an elevated source of tritium (i.e. landfill gas). However, for samples with low/modern tritium isotopics (rainwater), commercial separation and counting is a better fit.

  15. A Survey of Information Source Preferences of Parents of Individuals with Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Gibson, Amelia N.; Kaplan, Samantha; Vardell, Emily

    2017-01-01

    For parents of children with an Autism spectrum disorder (ASD), high quality, easily accessible information and a strong peer network can be the key to raising a happy, healthy child, and maintaining family well-being and emotional resilience. This article reports the findings of an anonymous survey examining the information source preferences for…

  16. Sources of HIV-Prevention Information for Individuals at High Risk.

    ERIC Educational Resources Information Center

    Sagrestano, Lynda M.; Heiss-Wendt, Renate M.; Mizan, Ainon N.; Kittleson, Mark J.; Sarvela, Paul D.

    2001-01-01

    Identified the best methods of reaching people at high risk with HIV-prevention messages. Data from men who had sex with men, injection drug users, sex workers, HIV-positive people, heterosexuals, migrant workers, and perinatal women indicated that over 70 percent were exposed to HIV-prevention messages, though sources of exposure varied by risk…

  17. The Role and Sources of Individual Differences in Critical-Analytic Thinking: A Capsule Overview

    ERIC Educational Resources Information Center

    Bolger, Donald J.; Mackey, Allyson P.; Wang, Min; Grigorenko, Elena L.

    2014-01-01

    Critical-analytic thinking is typically conceived as a meta-construct that arises at the junction of a problem state (i.e., a situation that requires analysis that challenges previous assumptions) and an individual (i.e., an entity with the capacity to exercise critical-analytic thinking). With regard to the latter, there is a substantial body of…

  18. The Role and Sources of Individual Differences in Critical-Analytic Thinking: A Capsule Overview

    ERIC Educational Resources Information Center

    Bolger, Donald J.; Mackey, Allyson P.; Wang, Min; Grigorenko, Elena L.

    2014-01-01

    Critical-analytic thinking is typically conceived as a meta-construct that arises at the junction of a problem state (i.e., a situation that requires analysis that challenges previous assumptions) and an individual (i.e., an entity with the capacity to exercise critical-analytic thinking). With regard to the latter, there is a substantial body of…

  19. The diffuse source at the center of LMC SNR 0509–67.5 is a background galaxy at z = 0.031

    SciTech Connect

    Pagnotta, Ashley; Walker, Emma S.; Schaefer, Bradley E.

    2014-06-20

    Type Ia supernovae (SNe Ia) are well-known for their use in the measurement of cosmological distances, but our continuing lack of concrete knowledge about their progenitor stars is both a matter of debate and a source of systematic error. In our attempts to answer this question, we presented unambiguous evidence that LMC SNR 0509–67.5, the remnant of an SN Ia that exploded in the Large Magellanic Cloud 400 ± 50 yr ago, did not have any point sources (stars) near the site of the original supernova explosion, from which we concluded that this particular supernova must have had a progenitor system consisting of two white dwarfs. There is, however, evidence of nebulosity near the center of the remnant, which could have been left over detritus from the less massive WD, or could have been a background galaxy unrelated to the supernova explosion. We obtained long-slit spectra of the central nebulous region using GMOS on Gemini South to determine which of these two possibilities is correct. The spectra show Hα emission at a redshift of z = 0.031, which implies that the nebulosity in the center of LMC SNR 0509–67.5 is a background galaxy, unrelated to the supernova.

  20. Aircraft noise reduction technology. [to show impact on individuals and communities, component noise sources, and operational procedures to reduce impact

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Aircraft and airport noise reduction technology programs conducted by NASA are presented. The subjects discussed are: (1) effects of aircraft noise on individuals and communities, (2) status of aircraft source noise technology, (3) operational procedures to reduce the impact of aircraft noise, and (4) NASA relations with military services in aircraft noise problems. References to more detailed technical literature on the subjects discussed are included.

  1. Sources of variation in HPG axis reactivity and individually consistent elevation of sex steroids in a female songbird

    PubMed Central

    Rosvall, Kimberly A.; Burns, Christine M. Bergeon; Hahn, Thomas P.; Ketterson, Ellen D.

    2013-01-01

    Understanding sources of individual differences in steroid hormone production has important implications for the evolution of reproductive and social behaviors. In females in particular, little is known about the mechanistic sources of these individual differences, despite established linkages between sex steroids and a variety of fitness-related traits. Using captive female dark-eyed juncos (Junco hyemalis) from two subspecies, we asked how variation in different components of the hypothalamo-pituitary-gonadal (HPG) axis related to variation in testosterone production among females, and we compared females to males in multiple components of the HPG axis. We demonstrated consistent individual differences in testosterone elevation in response to challenges with luteinizing hormone (LH) and gonadotropin-releasing hormone (GnRH). These hormone challenges led to more LH production but less testosterone production in females than males, and the sexes differed in some but not all measures of sensitivity to hormones along the HPG axis. Similar to findings in males, variation in testosterone production among females was not related to variation in LH production, gonadal LH-receptor mRNA abundance, or hypothalamic abundance of androgen receptor mRNA or aromatase mRNA. Rather, the primary source of individual variation in circulating steroids appears to the gonad, a conclusion further supported by positive correlations between testosterone and estradiol production. Unlike males, females did not differ by subspecies in any of the endocrine parameters that we assessed, suggesting some degree of independent evolution between the two sexes. Our results highlight the sources of physiological variation that may underlie the evolution of hormone-mediated phenotypes in females. PMID:24090613

  2. Individual variation in the swimming performance of fishes: An overlooked source of variation in toxicity studies

    SciTech Connect

    Kolok, A.S. ||; Plaisance, E.P.; Abdelghani, A.

    1998-02-01

    A commonly used indicator of sublethal stress in fish is impaired swimming performance. Analysis of performance data usually employs a simple comparison, in which the mean of a stressed group of fish is compared to that of a control group. Although such a comparison is satisfactory in many cases, a comparison emphasizing individual variation in performance can yield valuable information unattainable by a means comparison. In this experiment, the authors determined critical swimming speeds of subadult male fathead minnows before and after exposure to contaminated sediments from Devil`s Swamp, Louisiana, USA. The data were then analyzed using a means comparison and an individual approach to illustrate the differences in explanatory power between the two approaches.

  3. Personality as a Source of Individual Differences in Cognition among Older African Americans

    PubMed Central

    Aiken-Morgan, Adrienne T.; Bichsel, Jacqueline; Allaire, Jason C.; Savla, Jyoti; Edwards, Christopher L.; Whitfield, Keith E.

    2012-01-01

    Previous research suggests that demographic factors are important correlates of cognitive functioning in African Americans; however, less attention has been given to the influence of personality. The present study explored how dimensions and facets of personality predicted individual variability in cognition in a sample of older African Americans from the Baltimore Study of Black Aging. Cognition was assessed by verbal learning and attention/working memory measures. Personality was measured by the NEO Personality Inventory. Linear regressions controlling for demographic factors showed that Neuroticism, Openness, and Agreeableness were significant regression predictors of cognitive performance. Individual facets of all five personality dimensions were also associated with cognitive performance. These findings suggest personality is important in understanding variability in cognition among older African Americans. PMID:22962505

  4. The contribution of z ≲ 6 sources to the spatial coherence in the unresolved cosmic near-infrared and X-ray backgrounds

    SciTech Connect

    Helgason, K.; Ricotti, M.; Cappelluti, N.; Hasinger, G.; Kashlinsky, A.

    2014-04-10

    A spatial clustering signal has been established in Spitzer/IRAC measurements of the unresolved cosmic near-infrared background (CIB) out to large angular scales, ∼1°. This CIB signal, while significantly exceeding the contribution from the remaining known galaxies, was further found to be coherent at a highly statistically significant level with the unresolved soft cosmic X-ray background (CXB). This measurement probes the unresolved CXB to very faint source levels using deep near-IR source subtraction. We study contributions from extragalactic populations at low to intermediate redshifts to the measured positive cross-power signal of the CIB fluctuations with the CXB. We model the X-ray emission from active galactic nuclei (AGNs), normal galaxies, and hot gas residing in virialized structures, calculating their CXB contribution including their spatial coherence with all infrared emitting counterparts. We use a halo model framework to calculate the auto and cross-power spectra of the unresolved fluctuations based on the latest constraints of the halo occupation distribution and the biasing of AGNs, galaxies, and diffuse emission. At small angular scales (≲ 1'), the 4.5 μm versus 0.5-2 keV coherence can be explained by shot noise from galaxies and AGNs. However, at large angular scales (∼10'), we find that the net contribution from the modeled populations is only able to account for ∼3% of the measured CIB×CXB cross-power. The discrepancy suggests that the CIB×CXB signal originates from the same unknown source population producing the CIB clustering signal out to ∼1°.

  5. The Contribution of z < or Approx. 6 Sources to the Spatial Coherence in the Unresolved Cosmic Near-Infrared and X-Ray Backgrounds

    NASA Technical Reports Server (NTRS)

    Helgason, K.; Cappelluti, N.; Hasinger, G.; Kashlinsky, A.; Ricotti, M.

    2014-01-01

    A spatial clustering signal has been established in Spitzer/IRAC measurements of the unresolved cosmic near-infrared background (CIB) out to large angular scales, approx. 1deg. This CIB signal, while significantly exceeding the contribution from the remaining known galaxies, was further found to be coherent at a highly statistically significant level with the unresolved soft cosmic X-ray background (CXB). This measurement probes the unresolved CXB to very faint source levels using deep near-IR source subtraction.We study contributions from extragalactic populations at low to intermediate redshifts to the measured positive cross-power signal of the CIB fluctuations with the CXB. We model the X-ray emission from active galactic nuclei (AGNs), normal galaxies, and hot gas residing in virialized structures, calculating their CXB contribution including their spatial coherence with all infrared emitting counterparts. We use a halo model framework to calculate the auto and cross-power spectra of the unresolved fluctuations based on the latest constraints of the halo occupation distribution and the biasing of AGNs, galaxies, and diffuse emission. At small angular scales (1), the 4.5microns versus 0.5-2 keV coherence can be explained by shot noise from galaxies and AGNs. However, at large angular scales (approx.10), we find that the net contribution from the modeled populations is only able to account for approx. 3% of the measured CIB×CXB cross-power. The discrepancy suggests that the CIB×CXB signal originates from the same unknown source population producing the CIB clustering signal out to approx. 1deg.

  6. Bone marrow plasma cells are a primary source of serum HIV-1-specific antibodies in chronically infected individuals.

    PubMed

    Montezuma-Rusca, Jairo M; Moir, Susan; Kardava, Lela; Buckner, Clarisa M; Louie, Aaron; Kim, Leo J Y; Santich, Brian H; Wang, Wei; Fankuchen, Olivia R; Diaz, Gabriella; Daub, Janine R; Rosenzweig, Sergio D; Chun, Tae-Wook; Li, Yuxing; Braylan, Raul C; Calvo, Katherine R; Fauci, Anthony S

    2015-03-15

    Several potent and broadly neutralizing Abs to HIV-1 have been isolated recently from peripheral blood B cells of infected individuals, based on prescreening of Ab activity in the serum. However, little is known regarding the cells that make the Abs that circulate in the blood. Accordingly, we investigated the most likely source, the bone marrow, of chronically HIV-1-infected individuals who were not receiving antiretroviral therapy. Increased frequencies of plasma cells, as well as B cell precursors, namely preB-I and preB-II, and decreased frequencies of mature B cells were observed in bone marrow aspirates of these individuals compared with HIV-negative counterparts. Increased frequencies of bone marrow plasma cells are consistent with known hallmarks of HIV-1 infection, namely hypergammaglobulinemia and increased frequencies of peripheral blood plasmablasts. Levels of HIV-1 envelope (Env)-binding and HIV-1-neutralizing Abs were measured in serum, and corresponding frequencies of Ab-secreting or Env-binding cells were measured in the blood (plasmablasts and memory B cells) and in the bone marrow (plasma cells). A strong correlation was observed between serum HIV-1-specific Abs and Env-specific bone marrow-derived plasma cells, but not circulating plasmablasts or memory B cells. These findings demonstrate that, despite HIV-1-induced phenotypic and functional B cell dysregulation in the peripheral blood and secondary lymphoid tissues, bone marrow plasma cells remain a primary source for circulating HIV-1-specific Abs in HIV-1-infected individuals.

  7. X-ray background studies with Ariel 5 and Copernicus observations of the X-ray source: OAO1653-40

    NASA Astrophysics Data System (ADS)

    Pollard, G. S. G.

    1980-05-01

    The MSSL/UCL X-ray proportional counter onboard the Ariel 5 satellite has been used to examine the spectra of the 2 to 20 keV X-ray background in order to search for any line emissions. A review of the history and possible production mechanisms of the X-ray background is presented. In particular a critical analysis of the published data, which have shown there to be a possible break at 20 - 30 keV in the background, is included. A description of normal (i.e. stellar) data analysis techniques is given with an extension describing modifications which have allowed the analysis of the data so as to extract the X-ray background. Spectra of the 2 - 20 keV background are presented along with upper limits to any line emission. The analysis of these data includes an extensive 'post-launch' spectral calibration of the instrument. In particular, higher energy photon losses in multi-wire proportional counters is described. An examination of the spacecraft's environment is also presented and much discussion is given as to the possible methods of eliminating the contaminating effect that charged particles have on the proportional counter data. Using these methods, attempts have been made to predict charged particle intensities by use of various models involving spacecraft and experiment parameters. One chapter of this dissertation is devoted to the study of X-ray background spatial intensity fluctuations. A novel method of fluctuations analysis, which uses the experiment C quadrant mode of data collection, is described. Fluctuation limits derived by 'standard' analysis techniques and by this 'quadrant subtraction' technique are given. The final chapter describes the X-ray data obtained from the Copernicus MSSL/UCL 2.5 - 10 keV proportional counter which have led to the conclusion that the stellar binary system V861 Sco is a variable X-ray source. The combination of this result and the known limits for the mass of the system indicate that the secondary is a compact object and is

  8. Characterization of a heterogeneous DNAPL source zone in the Borden aquifer using partitioning and interfacial tracers: residual morphologies and background sorption.

    PubMed

    Hartog, Niels; Cho, Jaehyun; Parker, Beth L; Annable, Michael D

    2010-06-25

    A partitioning interwell tracer test (PITT) was performed in the Borden sand aquifer to characterize an aged heterogeneous DNAPL source zone. This zone evolved during 5 years of natural groundwater flow following the infiltration of 50 L chlorinated solvents DNAPL. To assess the lateral variability of remaining DNAPL mass and morphology, four sweepzones were analyzed. The low saturation residual nature of the source zone required correction of tracer breakthrough data for natural background sorption. Corrected estimates of the DNAPL percentage remaining (total 13.2-16.6%), average saturation (0.05-0.18%) and distribution across the sweepzones were in good agreement with previous findings based on detailed transect monitoring, core analyses and ground-penetrating radar reflection. Using a newly defined metric "average spherical radius equivalent (ASRE)", sweepzone estimates of the average size of DNAPL presence indicated the dominance of single pore DNAPL blobs and suggested the absence of DNAPL pools. Tracer tests indicated that DNAPL presence in the most DNAPL depleted sweepzone was potentially overestimated due to increased sediment sorption by residualized Sudan IV that was added to the DNAPL infiltrate. As hydrophobic compounds are normally present in spent solvent DNAPL, this suggests that additional sorption needs to be considered when using PITTs to characterize aged DNAPL source zones.

  9. Observations of organic trace gases during ITCT: Characterization of sources, background, and long-range transport to the US West coast and eastern Pacific atmosphere

    NASA Astrophysics Data System (ADS)

    Atlas, E.; Donnelly, S.; Stroud, V.; Schauffler, S.; Johnson, K.; Schwaller, N.; Hubler, G.; Parrish, D.; Holloway, J.; Trainer, M.

    2002-12-01

    The NOAA ITCT (Intercontinental Transport and Chemical Transformation) mission examined the processes that impact the chemical composition of the atmosphere in the eastern North Pacific Ocean and along the West Coast of the United States. The mission took place during April - May, 2002, when long-range transport to the US West Coast from downwind sources in Asia and beyond is most favorable. As part of the atmospheric chemistry payload on the NOAA P3 aircraft, whole air samples were collected for analysis of a variety of organic trace gases, including methane, NMHC, halocarbons, organic nitrates, and selected sulfur species. Mission flight tracks were designed to examine regions characteristic of the background atmosphere, and regions impacted by specific point sources, larger urban sources, and long-range transport. In this presentation we summarize the organic trace gas measurements and relationships from the whole air samples, characterize signatures of emissions from the west coast urban areas, and identify signatures of long-range trans-Pacific transport.

  10. Queueing analysis of synchronous time division multiplexing with individual source buffering

    NASA Technical Reports Server (NTRS)

    Clare, L.

    1982-01-01

    Synchronous time division multiplexing is analyzed. Packets of information arrive at the system as a compound Poisson process, and are transmitted only during individual periodic intervals. Packet arrivals are blocked (lost) if the system has a finite capacity and is congested. Using the theory of semiregenerative processes, the distribution of the number of packets in the system (system size) is found. This nonstationary distribution is used to determine the complete system behavior, including the delay distributions, the blocking probability, and the density of the system size at arrival instants. Numerical examples illustrate applications of the results given.

  11. PrestOMIC, an open source application for dissemination of proteomic datasets by individual laboratories.

    PubMed

    Howes, Charles G; Foster, Leonard J

    2007-06-06

    Technological advances in mass spectrometry and other detection methods are leading to larger and larger proteomics datasets. However, when papers describing such information are published the enormous volume of data can typically only be provided as supplementary data in a tabular form through the journal website. Several journals in the proteomics field, together with the Human Proteome Organization's (HUPO) Proteomics Standards Initiative and institutions such as the Institute for Systems Biology are working towards standardizing the reporting of proteomics data, but just defining standards is only a means towards an end for sharing data. Data repositories such as ProteomeCommons.org and the Open Proteomics Database allow for public access to proteomics data but provide little, if any, interpretation. Here we describe PrestOMIC, an open source application for storing mass spectrometry-based proteomic data in a relational database and for providing a user-friendly, searchable and customizable browser interface to share one's data with the scientific community. The underlying database and all associated applications are built on other existing open source tools, allowing PrestOMIC to be modified as the data standards evolve. We then use PrestOMIC to present a recently published dataset from our group through our website.

  12. Chronologically sampled flight feathers permits recognition of individual molt-migrants due to varying protein sources

    PubMed Central

    Fox, Anthony D.; Daniel, Thomas; Kelly, Jeffrey F.

    2015-01-01

    This is a proof of concept paper based on chronological samples of growing feathers from geese thought to be molt-migrants. When molt-migrant birds initiate molt shortly after migrating to a new isoscape, isotope values measured along the length of their feathers should change continuously. To assess long-term changes and daily cycling in δ15N and δ13C values, we serially sampled a growing primary from three presumed molt-migrant geese. Two showed changing δ15N signatures along the length of their growing primary, indicating they were molt-migrants, while the third, presumably a resident, showed no change. We then resampled these feathers at closer intervals for evidence of the predicted diel cycle in the use of exogenous and endogenous protein for feather growth, generated by the diel feeding cycle of these geese. As predicted, a periodicity of ca. 24 h in δ15N values was found along the primary of the two equilibrating geese, but not in the other goose that was probably a resident. Our results demonstrate that chronological sampling along the length of individual primaries holds great potential for identifying individuals that are molt-migrants. PMID:25649835

  13. Day-night differences in the composition and sources of carbonaceous aerosol at a polluted regional background site in the Netherlands

    NASA Astrophysics Data System (ADS)

    Dusek, Ulrike; Broekema, Elise; Holzinger, Rupert; Röckmann, Thomas; Meijer, Harro

    2017-04-01

    the summer, when biomass combustion is a small source, its relative contribution increases between 19:00 and 07:00. However, the diurnal changes in source contributions are relatively moderate (e.g., the biomass burning contribution to TC increased from 31% to 43% for the winter sample with the most distinct day-night difference.) This highlights the importance of long-range transport as a source of the carbonaceous aerosol in this region. First results from chemical composition measurements on four of the samples show that the concentration of less refractory organic carbon (desorption temperature up to 200 °C) increases at night-time much more strongly than the concentration of the more refractory carbon. Similarly, the concentration of small organic compounds with m/z < 100 also increases more strongly than heavier compounds. This indicates partitioning of semi-volatile OC as a possible additional night-time source. The chemical composition will be studied in more detail, focusing on diurnal changes in O/C ratios, individual compounds and compound classes, such as hydrocarbons or organic acids. Dusek, U., Meusinger, C., Oyama, B., Ramon, W., de Wilde, P., Holzinger, R., and Röckmann, T.: A thermal desorption system for measuring δ 13 C ratios on organic aerosol, Journal of aerosol science, 66, 72-82, 2013. Holzinger, R., Williams, J., Herrmann, F., Lelieveld, J., Donahue, N., Röckmann, T., 2010. Aerosol analysis using a Thermal-Desorption Proton-Transfer-Reaction Mass Spectrometer (TD-PTR-MS): a new approach to study processing of organic aerosols. Atmospheric chemistry and physics 10, 2257-2267.

  14. An upper limit on the cosmic-ray luminosity of individual sources from gamma-ray observations

    SciTech Connect

    Supanitsky, A.D.; Souza, V. de E-mail: vitor@ifsc.usp.br

    2013-12-01

    Different types of extragalactic objects are known to produce TeV gamma-rays. Some of these objects are the most probable candidates to accelerate cosmic rays up to 10{sup 20} eV. It is very well known that gamma-rays can be produced as a result of the cosmic ray propagation through the intergalactic medium. These gamma-rays contribute to the total flux observed in the direction of the source. In this paper we propose a new method to derive an upper limit on the cosmic-ray luminosity of an individual source based on the measured upper limit on the integral flux of GeV-TeV gamma-rays. We show how it is possible to calculate an upper limit on the cosmic-ray luminosity of a particular source and we explore the parameter space in which the current GeV-TeV gamma-ray measurements can offer a useful determination. We study in detail two particular sources, Pictor A and NGC 7469, and we calculate the upper limit on the proton luminosity of each source based on the upper limit on the integral gamma-ray flux measured by the H.E.S.S. telescopes.

  15. Vulnerability Assessment of Groundwater Resources by Nutrient Source Apportionment to Individual Groundwater Wells: A Case Study in North Carolina

    NASA Astrophysics Data System (ADS)

    Ayub, R.; Obenour, D. R.; Keyworth, A. J.; Genereux, D. P.; Mahinthakumar, K.

    2016-12-01

    Groundwater contamination by nutrients (nitrogen and phosphorus) is a major concern in water table aquifers that underlie agricultural areas in the mid-Atlantic Coastal Plain of the United States. High nutrient concentrations leaching into shallow groundwater can lead to human health problems and eutrophication of receiving surface waters. Liquid manure from concentrated animal feeding operations (CAFOs) stored in open-air lagoons and applied to spray fields can be a significant source of nutrients to groundwater, along with septic waste. In this study, we developed a model-based methodology for source apportionment and vulnerability assessment using sparse groundwater quality sampling measurements for Duplin County, North Carolina (NC), obtained by the NC Department of Environmental Quality (NC DEQ). This model provides information relevant to management by estimating the nutrient transport through the aquifer from different sources and addressing the uncertainty of nutrient contaminant propagation. First, the zones of influence (dependent on nutrient pathways) for individual groundwater monitoring wells were identified using a two-dimensional vertically averaged groundwater flow and transport model incorporating geologic uncertainty for the surficial aquifer system. A multiple linear regression approach is then applied to estimate the contribution weights for different nutrient source types using the nutrient measurements from monitoring wells and the potential sources within each zone of influence. Using the source contribution weights and their uncertainty, a probabilistic vulnerability assessment of the study area due to nutrient contamination is performed. Knowledge of the contribution of different nutrient sources to contamination at receptor locations (e.g., private wells, municipal wells, stream beds etc.) will be helpful in planning and implementation of appropriate mitigation measures.

  16. Source apportionment of PM2.5 at a regional background site in North China using PMF linked with radiocarbon analysis: insight into the contribution of biomass burning

    NASA Astrophysics Data System (ADS)

    Zong, Zheng; Wang, Xiaoping; Tian, Chongguo; Chen, Yingjun; Qu, Lin; Ji, Ling; Zhi, Guorui; Li, Jun; Zhang, Gan

    2016-09-01

    Source apportionment of fine particles (PM2.5) at a background site in North China in the winter of 2014 was done using statistical analysis, radiocarbon (14C) measurement and positive matrix factorization (PMF) modeling. Results showed that the concentration of PM2.5 was 77.6 ± 59.3 µg m-3, of which sulfate (SO42-) concentration was the highest, followed by nitrate (NO3-), organic carbon (OC), elemental carbon (EC) and ammonium (NH4+). As demonstrated by backward trajectory, more than half of the air masses during the sampling period were from the Beijing-Tianjin-Hebei (BTH) region, followed by Mongolia and the Shandong Peninsula. Cluster analysis of chemical species suggested an obvious signal of biomass burning in the PM2.5 from the Shandong Peninsula, while the PM2.5 from the BTH region showed a vehicle emission pattern. This finding was further confirmed by the 14C measurement of OC and EC in two merged samples. The 14C result indicated that biogenic and biomass burning emission contributed 59 ± 4 and 52 ± 2 % to OC and EC concentrations, respectively, when air masses originated from the Shandong Peninsula, while the contributions fell to 46 ± 4 and 38 ± 1 %, respectively, when the prevailing wind changed and came from the BTH region. The minimum deviation between source apportionment results from PMF and 14C measurement was adopted as the optimal choice of the model exercises. Here, two minor overestimates with the same range (3 %) implied that the PMF result provided a reasonable source apportionment of the regional PM2.5 in this study. Based on the PMF modeling, eight sources were identified; of these, coal combustion, biomass burning and vehicle emission were the main contributors of PM2.5, accounting for 29.6, 19.3 and 15.9 %, respectively. Compared with overall source apportionment, the contributions of vehicle emission, mineral dust, coal combustion and biomass burning increased when air masses came from the BTH region, Mongolia and the Shandong

  17. Limits on the strength of individual gravitational wave sources using high-cadence observations of PSR B1937+21

    NASA Astrophysics Data System (ADS)

    Yi, Shuxu; Stappers, Benjamin W.; Sanidas, Sotirios A.; Bassa, Cees G.; Janssen, Gemma H.; Lyne, Andrew G.; Kramer, Michael; Zhang, Shuang-Nan

    2014-12-01

    We present the results of a search for gravitational waves (GWs) from individual sources using high-cadence observations of PSR B1937+21. The data were acquired from an intensive observation campaign with the Lovell telescope at Jodrell Bank, between 2011 June and 2013 May. The almost daily cadence achieved allowed us to be sensitive to GWs with frequencies up to 4.98 × 10-6 Hz, extending the upper bound of the typical frequency range probed by pulsar timing arrays. We used observations taken at three different radio frequencies with the Westerbork Synthesis Radio Telescope in order to correct for dispersion measure effects and scattering variances. The corrected timing residuals exhibited an unmodelled periodic noise with an amplitude of 150 ns and a frequency of 3.4 yr-1. As the signal is not present in the entire data set, we attributed it to the rotational behaviour of the pulsar, ruling out the possibilities of being either due to a GW or an asteroid as the cause. After removing this noise component, we placed limits on the GW strain of individual sources equalling to hs = 1.53 × 10-11 and hs = 4.99 × 10-14 at 10-7 Hz for random and optimal sources locations, respectively.

  18. Mixing state and sources of submicron regional background aerosols in the northern Qinghai-Tibet Plateau and the influence of biomass burning

    NASA Astrophysics Data System (ADS)

    Li, W. J.; Chen, S. R.; Xu, Y. S.; Guo, X. C.; Sun, Y. L.; Yang, X. Y.; Wang, Z. F.; Zhao, X. D.; Chen, J. M.; Wang, W. X.

    2015-12-01

    Transmission electron microscopy (TEM) was employed to obtain morphology, size, composition, and mixing state of background aerosols with diameter less than 1 μm in the northern Qinghai-Tibet Plateau (QTP) during 15 September to 15 October 2013. Individual aerosol particles mainly contained secondary inorganic aerosols (SIA - sulfate and nitrate) and organics during clean periods (PM2.5 mass concentration less than 2.5 μg m-3). The presence of K-Na-Cl associated with organics and an increase in soot particles suggest that an intense biomass burning event caused the highest PM2.5 concentrations (> 30 μg m-3) during the study. A large number fraction of the fly-ash-containing particles (21.73 %) suggests that coal combustion emissions in the QTP significantly contributed to air pollutants at the medium pollution level (PM2.5: 10-30 μg m-3). We concluded that emissions from biomass burning and from coal combustion both constantly contribute to anthropogenic particles in the QTP atmosphere. Based on size distributions of individual particles at different pollution levels, we found that gas condensation on existing particles is an important chemical process for the formation of SIA with organic coating. TEM observations show that refractory aerosols (e.g., soot, fly ash, and visible organic particles) likely adhere to the surface of SIA particles larger than 200 nm due to coagulation. Organic coating and soot on surface of the aged particles likely influence their hygroscopic and optical properties, respectively, in the QTP. To our knowledge, this study reports the first microscopic analysis of fine particles in the background QTP air.

  19. Long term observations of halogenated greenhouse gases in a European continental background station for assessing atmospheric trends, annual growth rates and emission sources

    NASA Astrophysics Data System (ADS)

    Maione, M.; Arduini, J.; Uguccioni, F.; Giostra, U.; Furlani, F.; Belfiore, L.; Cava, D.

    2009-04-01

    Climate altering halocarbons are continuously monitored at the atmospheric research station "O. Vittori" located on the top of Monte Cimone, Northern Apennines, Italy ( 2165 m asl), in the frame of the SOGE (System for Observation of halogenated Greenhouse gases in Europe) network, an integrated system based on a combination of observations and models aimed at assessing atmospheric trends, annual growth rates and at estimating European halocarbon emissions. The use of such a top-down approach is useful to ascertain compliance to International Protocols regulating production/emission of halogenated greenhouse gases. Establishing the baseline is essential both for estimating annual growth rates and because back attribution techniques are based on the clear identification of "above the background" data. That is particularly challenging in a Station like Monte Cimone characterised by a complex meteorological and source field. The approach proposed is based on the identification of the lowest concentration values in a given temporal range to which a ∆c representing variation due to instrumental error is added. Trends are evaluated by using a non-linear regression function, able to take into account both annual and seasonal variation. In order to identify source, regions baseline data are subtracted from the full data set and an inversion modelling cascade, which makes use of MM5 model to reproduce meteorological fields and of FLEXPART to simulate tracer dispersion, is used to find the best emissions map that fits the observations.

  20. The use of levoglucosan and radiocarbon for source apportionment of PM(2.5) carbonaceous aerosols at a background site in East China.

    PubMed

    Liu, Di; Li, Jun; Zhang, Yanlin; Xu, Yue; Liu, Xiang; Ding, Ping; Shen, Chengde; Chen, Yingjun; Tian, Chongguo; Zhang, Gan

    2013-09-17

    Samples of fine particulate matter (PM2.5) were collected during July 2009 to March 2010 at a regional background site in East China. The mass concentrations of organic carbon (OC) and elemental carbon (EC) were characterized by the highest levels in winter (December to February) and the lowest abundances in summer (June to August). Conversely, the concentrations of levoglucosan were higher in summer than in winter. The observations were associated to the anthropogenic air pollutions (predominantly fossil-fuel combustions) transport from the center and north China with the northwest winds in winter and large contribution of the open biomass burning activities in South China and East China in summer, which was evident by air-mass trajectories and MODIS satellite fire counts. To assign fossil and nonfossil contributions of carbonaceous matters, the radiocarbon contents in water-insoluble OC (WINSOC) and EC in 4 combined samples representing four seasons were analyzed using the isolation system established in China. The results indicated that biomass burning and biogenic sources (59%) were the major contribution to the WINSOC, whereas fossil fuel (78%) was the dominant contributor to the refractory EC at this site. The source variation obtained by radiocarbon was consistent with other indicators, such as the OC/EC ratios and the levoglucosan concentration. Biomass burning and biogenic emissions were found to predominate in the summer and autumn, whereas fossil fuel emissions predominate in winter and spring.

  1. Long-term quantitative field study of New Particle Formation (NPF) events as a source of Cloud Condensation Nuclei (CCN) in the urban background of Vienna

    NASA Astrophysics Data System (ADS)

    Dameto de España, C.; Wonaschütz, A.; Steiner, G.; Rosati, B.; Demattio, A.; Schuh, H.; Hitzenberger, R.

    2017-09-01

    Many studies have indicated New Particle Formation (NPF) events as an important source of CCN in the atmosphere. However, most of these studies are based on indirect determination of CCN concentrations or were of rather short duration. In this study, we present long-term measurements of CCN concentrations and particle number size distributions performed in the urban background of Vienna, Austria, spanning a period of two years. NPF events occurred on 70 of the 539 measurement days. For 38 of these events, concurrent CCN concentrations (measured at 0.5% supersaturation) are available. Direct comparisons of absolute CCN concentrations before and after an event, however, are inconclusive as other influences can lead to changes in CCN concentrations. In this study, we developed criteria to take local emissions of ultrafine particles, atmospheric mixing conditions and changes in air mass into account. A new normalization procedure (CCN/PM2.5) is introduced to account for dilution and concentration effects due to changes in boundary layer height. Other possible influences, such as weather conditions and traffic emissions were accounted for by tracking wind direction and velocity, as well as black carbon (BC) mass concentrations. On 15 event days, all criteria to exclude other influences were met. On 14 days, NPF was found to be a source of CCN (at 0.5% supersaturation), with concentration increases by up to 143%.

  2. Quantifying the contribution of individual dust sources to the summertime dust hotspot in the central and western Sahara

    NASA Astrophysics Data System (ADS)

    Ashpole, Ian; Washington, Richard; Engelstaedter, Sebastian

    2014-05-01

    The central and western Sahara (CWS), a huge area encompassing parts of Algeria, Niger, Mali and Mauritania, is the dustiest place on Earth during the northern hemisphere summer. This dust is known to come from a large number of disperse sources across the region, which have been identified predominantly from satellite observations. We utilise an automated scheme that tracks individual dust plumes in data from the spaceborne Spinning Enhanced Visible and Infrared Imager (SEVIRI), available every 15 minutes at ~0.03° spatial resolution, to quantify the contribution of dust plumes from known sources to the overall CWS dust hotspot in terms of 1) frequency of dust detection and 2) total plume Aerosol Optical Depth (also derived from SEVIRI data). Results show that dust sources in the south of the region, whose activation is strongly linked to the dynamics of the West African Monsoon and convective processes, make a significantly greater contribution to the dust hotspot than sources in central Algeria and northwest Mali that, while equally or even more frequently active, give rise to plumes that are much more spatially constricted and short lived.

  3. Source and thermal maturity of bitumen in Precambrian Nonesuch Formation inferred from isotopic compositions of individual normal alkanes

    SciTech Connect

    Hieshima, G.B. )

    1991-03-01

    As part of a continuing study of organic geochemistry of the 1.05 Ga Nonesuch Formation in the North American Mid-Continents rift, isotopic compositions of individual normal alkanes were measured using compound-specific isotopic analysis. This is a relatively new technique that can be used in conjunction with traditional biomarker analysis in interpretation of thermal maturity, oil-source rock correlation, and paleoecologic reconstruction. Carbon-isotopic compositions of individual normal alkanes from C{sub 15} to C{sub 25} in five bitumens and one oil from Nonesuch strata vary from {minus}28.8 to {minus}34.5{per thousand} (versus PDB). Within a given sample, isotopic compositions of n-alkanes span a range of 2 to 4 {per thousand}%. Homologues from C{sub 15} to C{sub 19} are isotopically light (depleted) by approximately 0.5{per thousand} relative to higher homologues from C{sub 20} to C{sub 25}. Two sources of normal alkanes are interpreted from the distribution of isotopic compositions. Based on chain length, the series from C{sub 15} to C{sub 19} may have been derived from algal components. Isotopically heavy, higher homologues are suspected to have been derived from bacterial sources. The pattern of isotopic compositions of bitumens is similar to that of the oil, demonstrating an oil-source rock relationship. Superimposed upon this primary, bimodal distribution of normal alkanes is the influence of thermal maturity on isotopic composition. Normal alkanes in samples of higher thermal maturity are enriched isotopically by 0.25 to 2{per thousand} relative to those of lower thermal maturity. Isotopic enrichment with increasing thermal maturity is interpreted to be the result of either addition of isotopically heavy components derived from kerogen and/or preferential loss through cracking of isotopically light components in bitumen.

  4. Examining sources of variation in HPG axis function among individuals and populations of the dark-eyed junco.

    PubMed

    Bergeon Burns, Christine M; Rosvall, Kimberly A; Hahn, Thomas P; Demas, Gregory E; Ketterson, Ellen D

    2014-02-01

    Gonadal steroids are important mediators of traits relevant to fitness, and thus may be targets of selection. However, more knowledge is needed about sources of variation along the endocrine axes that may contribute to functional variation in steroid levels. In a controlled captive environment, we studied males of two closely related subspecies of the dark-eyed junco (Junco hyemalis) that differ in testosterone-related phenotype, asking whether they also differ in testosterone (T), and assessing the contribution of the sequential links of the hypothalamic-pituitary-gonadal axis. When males of both subspecies were challenged with gonadotropin-releasing hormone (GnRH), they were similar in circulating luteinizing hormone (LH) and T responses. When challenged with exogenous LH, they again produced levels of T similar to one another, and to the levels produced in response to GnRH. However, the smaller, less ornamented, and less aggressive subspecies had greater abundance of mRNA for LH receptor in the testes and for androgen receptor in the rostral hypothalamus, suggesting potential differences in regulatory feedback. We suggest that circulating hormone levels may be less prone to evolutionary change than the responsiveness of individual hormone targets. Among individuals, T titers were highly repeatable whether males were challenged with GnRH or with LH, but LH produced in response to GnRH did not covary with T produced in response to LH. Testis mass, but not LH receptor transcript abundance, predicted individual variation in T responses. These data implicate the gonad, but not the pituitary, as an important source of individual variation in T production.

  5. Examining sources of variation in HPG axis function among individuals and populations of the dark-eyed junco

    PubMed Central

    Rosvall, Kimberly A.; Hahn, Thomas P.; Demas, Gregory E.; Ketterson, Ellen D.

    2013-01-01

    Gonadal steroids are important mediators of traits relevant to fitness, and thus may be targets of selection. However, more knowledge is needed about sources of variation along the endocrine axes that may contribute to functional variation in steroid levels. In a controlled captive environment, we studied males of two closely related subspecies of the dark-eyed junco (Junco hyemalis) that differ in testosterone-related phenotype, asking whether they also differ in testosterone (T), and assessing the contribution of the sequential links of the hypothalamo-pituitary-gonadal axis. When males of both subspecies were challenged with gonadotropin-releasing hormone (GnRH), they were similar in circulating luteinizing hormone (LH) and T responses. When challenged with exogenous LH, they again produced levels of T similar to one another, and to the levels produced in response to GnRH. However, the smaller, less ornamented, and less aggressive subspecies had greater abundance of mRNA for LH receptor in the testes and for androgen receptor in the rostral hypothalamus, suggesting potential differences in regulatory feedback. We suggest that circulating hormone levels may be less prone to evolutionary change than the responsiveness of individual hormone targets. Among individuals, T titers were highly repeatable whether males were challenged with GnRH or with LH, but LH produced in response to GnRH did not covary with T produced in response to LH. Testis mass, but not LH receptor transcript abundance, predicted individual variation in T responses. These data implicate the gonad, but not the pituitary, as an important source of individual variation in T production. PMID:24140626

  6. Predominant anthropogenic sources and rates of atmospheric mercury accumulation in southern Ontario recorded by peat cores from three bogs: comparison with natural "background" values (past 8000 years).

    PubMed

    Givelet, Nicolas; Roos-Barraclough, Fiona; Shotyk, William

    2003-12-01

    Peat cores from three bogs in southern Ontario provide a complete, quantitative record of net rates of atmospheric Hg accumulation since pre-industrial times. For comparison with modern values, a peat core extending back 8000 years was used to quantify the natural variations in Hg fluxes for this region, and their dependence on climatic change and land use history. The net mercury accumulation rates were separated into "natural" and "excess" components by comparing the Hg/Br ratios of modern samples with the long-term, pre-anthropogenic average Hg/Br. The average background mercury accumulation rate during the pre-anthropogenic period (from 5700 years BC to 1470 AD) was 1.4 +/- 1.0 microg m(-2) per year (n = 197). The beginning of Hg contamination from anthropogenic sources dates from AD 1475 at the Luther Bog, corresponding to biomass burning for agricultural activities by Native North Americans. During the late 17th and 18th centuries, deposition of anthropogenic Hg was at least equal to that of Hg from natural sources. Anthropogenic inputs of Hg to the bogs have dominated continuously since the beginning of the 19th century. The maximum Hg accumulation rates decrease in the order Sifton Bog, in the City of London, Ontario (141 microg Hg m(-2) per year), Luther Bog in an agricultural region (89 microg Hg m(-2) per year), and Spruce Bog which is in a comparatively remote, forested region (54 microg Hg m(-2) per year). Accurate age dating of recent peat samples using the bomb pulse curve of 14C shows that the maximum rate of atmospheric Hg accumulation occurred during AD 1956 and 1959 at all sites. In these (modern) samples, the Hg concentration profiles resemble those of Pb, an element which is known to be immobile in peat bogs. The correlation between these two metals, together with sulfur, suggests that the predominant anthropogenic source of Hg (and Pb) was coal burning. While Hg accumulation rates have gone into strong decline since the late 1950's, Hg

  7. On the determination of the cosmic infrared background radiation from the high-energy spectrum of extragalactic gamma-ray sources

    NASA Technical Reports Server (NTRS)

    Dwek, Eli; Slavin, Jonathan

    1994-01-01

    In a recent paper Stecker, De Jager, & Salamon have suggested using the observed approximately MeV to TeV spectra of extragalactic gamma-ray sources as probes of the local density of the cosmic infrared background radiation (CIBR) and have subsequently claimed a first possible measurement of the CIBR from the analysis of the gamma-ray spectrum of Mrk 421 (De Jager, Stecker, & Salamon). The CIBR from normal galaxies consists of two components: a stellar emission component (CIBRs), and a thermal dust emission component (CIBRd). Photons with energies in the approximately 0.1-2 TeV range interact primarily with the CIBRs, whereas interactions with CIBRd dominate the absorption of photons in the approximately 2-100 TeV energy range. SDS 92 and DSS94 considered only the interaction of the gamma-rays with the dust emission component of the CIBR. We present here an improved analysis of the absorption of extragalactic TeV gamma rays by the CIBR, taking the dual nature of its origin into account. Applying the analysis to the observed gamma-ray spectrum of Mrk 421, a BL Lac object at z = 0.031, we find agreement with DSS94 tentative evidence for absorption by the CINRs. Our analysis therefore limits the detection of the CIBR to the approximately 15-40 micron wavelength regime which, considering the uncertainties in the highest energy (greater than 4 TeV) data and ion the possibility of absorption inside the source, many turn out to be an upper limit on its energy density. At shorter wavelengths (lambda approximately = 1-15 microns), where the gamma-ray interactions are dominated by the CIBRs, our analysis definitely yields only an upper limit on the energy density of the CIBR. In contrast, DSS94 have claimed a possible first measurement of the CIBR over the entire 1-120 micron wavelength region. The upper limit on the CIBRs and tentative detection of the CIBRd are consistent with normal galaxies contributing most of the energy to the CIBR, and constrain the contribution of

  8. On the determination of the cosmic infrared background radiation from the high-energy spectrum of extragalactic gamma-ray sources

    NASA Technical Reports Server (NTRS)

    Dwek, Eli; Slavin, Jonathan

    1994-01-01

    In a recent paper Stecker, De Jager, & Salamon have suggested using the observed approximately MeV to TeV spectra of extragalactic gamma-ray sources as probes of the local density of the cosmic infrared background radiation (CIBR) and have subsequently claimed a first possible measurement of the CIBR from the analysis of the gamma-ray spectrum of Mrk 421 (De Jager, Stecker, & Salamon). The CIBR from normal galaxies consists of two components: a stellar emission component (CIBRs), and a thermal dust emission component (CIBRd). Photons with energies in the approximately 0.1-2 TeV range interact primarily with the CIBRs, whereas interactions with CIBRd dominate the absorption of photons in the approximately 2-100 TeV energy range. SDS 92 and DSS94 considered only the interaction of the gamma-rays with the dust emission component of the CIBR. We present here an improved analysis of the absorption of extragalactic TeV gamma rays by the CIBR, taking the dual nature of its origin into account. Applying the analysis to the observed gamma-ray spectrum of Mrk 421, a BL Lac object at z = 0.031, we find agreement with DSS94 tentative evidence for absorption by the CINRs. Our analysis therefore limits the detection of the CIBR to the approximately 15-40 micron wavelength regime which, considering the uncertainties in the highest energy (greater than 4 TeV) data and ion the possibility of absorption inside the source, many turn out to be an upper limit on its energy density. At shorter wavelengths (lambda approximately = 1-15 microns), where the gamma-ray interactions are dominated by the CIBRs, our analysis definitely yields only an upper limit on the energy density of the CIBR. In contrast, DSS94 have claimed a possible first measurement of the CIBR over the entire 1-120 micron wavelength region. The upper limit on the CIBRs and tentative detection of the CIBRd are consistent with normal galaxies contributing most of the energy to the CIBR, and constrain the contribution of

  9. Measurement Invariance and Latent Mean Differences in the Reynolds Intellectual Assessment Scales (RIAS): Does the German Version of the RIAS Allow a Valid Assessment of Individuals with a Migration Background?

    PubMed Central

    Gygi, Jasmin T.; Fux, Elodie; Grob, Alexander; Hagmann-von Arx, Priska

    2016-01-01

    This study examined measurement invariance and latent mean differences in the German version of the Reynolds Intellectual Assessment Scales (RIAS) for 316 individuals with a migration background (defined as speaking German as a second language) and 316 sex- and age-matched natives. The RIAS measures general intelligence (single-factor structure) and its two components, verbal and nonverbal intelligence (two-factor structure). Results of a multi-group confirmatory factor analysis showed scalar invariance for the two-factor and partial scalar invariance for the single-factor structure. We conclude that the two-factor structure of the RIAS is comparable across groups. Hence, verbal and nonverbal intelligence but not general intelligence should be considered when comparing RIAS test results of individuals with and without a migration background. Further, latent mean differences especially on the verbal, but also on the nonverbal intelligence index indicate language barriers for individuals with a migration background, as subtests corresponding to verbal intelligence require higher skills in German language. Moreover, cultural, environmental, and social factors that have to be taken into account when assessing individuals with a migration background are discussed. PMID:27846270

  10. Measurement Invariance and Latent Mean Differences in the Reynolds Intellectual Assessment Scales (RIAS): Does the German Version of the RIAS Allow a Valid Assessment of Individuals with a Migration Background?

    PubMed

    Gygi, Jasmin T; Fux, Elodie; Grob, Alexander; Hagmann-von Arx, Priska

    2016-01-01

    This study examined measurement invariance and latent mean differences in the German version of the Reynolds Intellectual Assessment Scales (RIAS) for 316 individuals with a migration background (defined as speaking German as a second language) and 316 sex- and age-matched natives. The RIAS measures general intelligence (single-factor structure) and its two components, verbal and nonverbal intelligence (two-factor structure). Results of a multi-group confirmatory factor analysis showed scalar invariance for the two-factor and partial scalar invariance for the single-factor structure. We conclude that the two-factor structure of the RIAS is comparable across groups. Hence, verbal and nonverbal intelligence but not general intelligence should be considered when comparing RIAS test results of individuals with and without a migration background. Further, latent mean differences especially on the verbal, but also on the nonverbal intelligence index indicate language barriers for individuals with a migration background, as subtests corresponding to verbal intelligence require higher skills in German language. Moreover, cultural, environmental, and social factors that have to be taken into account when assessing individuals with a migration background are discussed.

  11. Individual Differences in Neural Mechanisms of Selective Auditory Attention in Preschoolers from Lower Socioeconomic Status Backgrounds: An Event-Related Potentials Study

    ERIC Educational Resources Information Center

    Isbell, Elif; Wray, Amanda Hampton; Neville, Helen J.

    2016-01-01

    Selective attention, the ability to enhance the processing of particular input while suppressing the information from other concurrent sources, has been postulated to be a foundational skill for learning and academic achievement. The neural mechanisms of this foundational ability are both vulnerable and enhanceable in children from lower…

  12. Carbonaceous aerosol source apportionment using the Aethalometer model - evaluation by radiocarbon and levoglucosan analysis at a rural background site in southern Sweden

    NASA Astrophysics Data System (ADS)

    Martinsson, Johan; Azeem, Hafiz Abdul; Sporre, Moa K.; Bergström, Robert; Ahlberg, Erik; Öström, Emilie; Kristensson, Adam; Swietlicki, Erik; Eriksson Stenström, Kristina

    2017-03-01

    source apportionment. A performed sensitivity analysis suggests that this discrepancy can be explained by interference of non-light-absorbing biogenic carbon during winter. In summary, the Aethalometer model offers a cost-effective yet robust high-time-resolution source apportionment at rural background stations compared to a radiocarbon and levoglucosan alternative.

  13. Highlight on the indigenous organic molecules detected on Mars by SAM and potential sources of artifacts and backgrounds generated by the sample preparation

    NASA Astrophysics Data System (ADS)

    Buch, A.; Belmahdi, I.; Szopa, C.; Freissinet, C.; Glavin, D. P.; Coll, P. J.; Cabane, M.; Millan, M.; Eigenbrode, J. L.; Navarro-Gonzalez, R.; Stern, J. C.; Pinnick, V. T.; Coscia, D.; Teinturier, S.; Stambouli, M.; Dequaire, T.; Mahaffy, P. R.

    2015-12-01

    Among the experiments which explore the martian soil aboard the Curiosity Rover, SAM experiment is mainly dedicated to the search for indigenous organic compounds. To reach its goals SAM can operate in different analysis modes: Pyrolysis-GC-MS and Pyrolysis-MS (EGA). In addition SAM includes wet chemistry experiments [1] to supports extraction of polar organic compounds from solid samples that improves their detection either by increasing the release of chemical species from solid sample matrices, or by changing their chemical structure to make compounds more amenable to gas chromatography mass spectrometry (GCMS). The two wet chemistry experimental capabilities of SAM provide alternatives to the nominal inert-thermal desorption/pyrolysis analytical protocol and are more aptly suited for polar components: MTBSTFA derivatization [2-3] and TMAH thermochemolysis [4-5]. Here we focus on the MTBSTFA derivatization experiment. In order to build a support used to help the interpretation of SAM results, we have investigated the artifacts and backgrounds sources generated by the all analysis process: Solid sample were heated up to approximately 840°C at a rate of 35°C/min under He flow. For GC analyses, the majority of the gas released was trapped on a hydrocarbon trap (Tenax®) over a specific temperature range. Adsorbed volatiles on the GC injection trap (IT) were then released into the GC column (CLP-MXT 30m x 0.25mm x 0.25μm) by rapidly heating the IT to 300°C. Then, in order better understand the part of compounds detected coming from internal reaction we have performed several lab experiments to mimic the SAM device: Among the sources of artifact, we test: (1) the thermal stability and the organic material released during the degradation of Tenax® and carbosieve, (2) the impact of MTBSTFA and a mixture of DMF and MTBSTFA on the adsorbent, (3) the reaction between the different adsorbents (Tenax® and Carbosieve) and calcium perchlorate and then (4) the sources

  14. Accumulation, sources and health risks of trace metals in elevated geochemical background soils used for greenhouse vegetable production in southwestern China.

    PubMed

    Zhang, Haidong; Huang, Biao; Dong, Linlin; Hu, Wenyou; Akhtar, Mohammad Saleem; Qu, Mingkai

    2017-03-01

    Greenhouse vegetable cultivation with substantive manure and fertilizer input on soils with an elevated geochemical background can accumulate trace metals in soils and plants leading to human health risks. Studies on trace metal accumulation over a land use shift duration in an elevated geochemical background scenario are lacking. Accumulation characteristics of seven trace metals in greenhouse soil and edible plants were evaluated along with an assessment of the health risk to the consumers. A total of 118 greenhouse surface soils (0-20cm) and 30 vegetables were collected from Kunming City, Yunnan Province, southwestern China, and analyzed for total Cd, Pb, Cu, Zn, As, Hg, and Cr content by ICP-MS and AFS. The trace metals were ordered Cu>Cd>Hg>Zn>Pb>As>Cr in greenhouse soils accumulation level, and the geo-accumulation index suggested the soil more severely polluted with Cd, Cu, Hg and Zn. The greenhouse and open-field soils had significant difference in Cd, Cr and Zn. The duration of shift from paddy to greenhouse land-use significantly influenced trace metal accumulation with a dramatic change during five to ten year greenhouse land-use, and continuous increase of Cd and Hg. A spatial pattern from north to south for Cd and Hg and a zonal pattern for Cu and Zn were found. An anthropogenic source primarily caused trace metal accumulation, where the principal component analysis/multiple linear regression indicated a contribution 61.2%. While the assessment showed no potential risk for children and adults, the hazard health risks index was greater than one for adolescents. The extended duration of land use as greenhouses caused the trace metal accumulation, rotation in land use should be promoted to reduce the health risks.

  15. The 13C(α,n)16O reaction: A background source for underground astrophysics measurements and geo-neutrino measurements

    NASA Astrophysics Data System (ADS)

    Febbraro, Michael; Toomey, Rebecca; Deboer, James; Pain, Steven; Peters, William; Smith, Karl; Becchetti, Fred; Wiescher, Michael

    2016-09-01

    In this study, we present results for a neutron spectroscopic study of the 13C(α,n)16O reaction between E α = 3 . 5 and 7.5 MeV performed at the University of Notre Dame Nuclear Science Laboratory. The neutron spectroscopy measurement was performed with deuterated liquid scintillator detectors capable of extracting neutron energy spectra without neutron time-of-flight measurement using spectral unfolding technique. This permitted extraction of the ground state contribution as well as excited state contributions to the total reaction cross section. The usefulness of this technique for the measurement of beam-induced neutron background sources in deep underground nuclear astrophysics measurements will be shown. Results showing the contributions of excited state components to the total cross section will be given and their implication to geo-neutrino measurements will be discussed. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, NSF Grant PHY0969456, PHY1401343, and Defense Nuclear Nonproliferation R&D (NA-22).

  16. 1-hour time resolution data of PM2.5 composition and gaseous precursors in background Milan: pollution sources and atmospheric processes, and their implications for air quality.

    NASA Astrophysics Data System (ADS)

    Bigi, Alessandro; Bianchi, Federico; De Gennaro, Gianluigi; Di Gilio, Alessia; Fermo, Paola; Ghermandi, Grazia; Prévôt, André; Urbani, Monia; Valli, Gianluigi; Vecchi, Roberta; Piazzalunga, Andrea

    2017-04-01

    Aim of this study is the investigation of processes leading to atmospheric pollutants formation and ageing in Milan, Po valley, i.e. one of the main hotspot region in Europe. Few 1-hour time resolution campaigns were accomplished in Milan urban area and none of these dealt with simultaneous characterization of atmospheric pollutants in both gas and particle phase. The present study is based on a thorough analysis of hourly data of atmospheric pollutants and of main PM2.5 compounds, and it includes several soluble inorganic aerosols (Cl-, NO2-, NO3-, SO42-, K+, Mg2+, Ca2+, Na+, NH4+), gases (HCl, HNO2, HNO3, NH3, NO, NO2, O3, SO2) organic, elemental and black carbon and meteorological parameters. The data proceed from an intensive sampling campaign in urban background Milan in summer 2012 (Bigi et al., 2017). Data analysis methods used include mean diurnal pattern on weekdays and Sundays, pollution roses, bivariate polar plots and statistical models using backtrajectories. Results show how nitrous acid (HONO) was mainly formed heterogeneously at nighttime, with a dependence of its formation rate on NO2 consistent with observations during the last HONO campaign in Milan in summer 1998, although since 1998 a drop in HONO levels occurred following to the decrease of its precursors. Nitrate showed two main formation mechanisms: one occurring through N2O5 at nighttime and leading to nitrate formation onto existing particles; another occurring both daytime and nighttime following the homogeneous reaction of ammonia gas with nitric acid gas. Air masses reaching Milan influenced nitrate formation depending on their content in ammonia and the timing of arrival. Notwithstanding the low level of SO2 in Milan, its peaks were associated to point source emissions in the Po valley or shipping and power plant emissions SW of Milan, beyond the Apennines. A distinctive pattern for HCl was observed, featured by an afternoon peak and a morning minimum, and best correlated to

  17. Unemployment as a source of mental distress to individuals and their family: Unemployed parents' perceptions during the economic recession.

    PubMed

    Frasquilho, Diana; de Matos, Margarida Gaspar; Santos, Teresa; Gaspar, Tânia; Caldas de Almeida, J M

    2016-08-01

    Due to the economic recession, several people in Europe became unemployed. This situation may risk their mental health. This study explored parents' perceptions about their unemployment's effects in daily life during the recession. A total of 59 unemployed parents (40.7% fathers and 59.3% mothers), ageing 44.4 years (±6.2), answer a question on how the unemployment affected their family lives. Thematic analysis was used to analyse data. The findings suggest that unemployment is a source of adult and youth mental distress and of economic hardship and changes in family relations. Support to unemployed individuals and their families could benefit from these insights when granting the needed financial and socioemotional assistance. © The Author(s) 2016.

  18. Individual differences affecting caffeine intake. Analysis of consumption behaviours for different times of day and caffeine sources.

    PubMed

    Penolazzi, Barbara; Natale, Vincenzo; Leone, Luigi; Russo, Paolo Maria

    2012-06-01

    The main purpose of the present study was to investigate the individual variables contributing to determine the high variability in the consumption behaviours of caffeine, a psychoactive substance which is still poorly investigated in comparison with other drugs. The effects of a large set of specific personality traits (i.e., Impulsivity, Sensation Seeking, Anxiety, Reward Sensitivity and Circadian Preference) were compared along with some relevant socio-demographic variables (i.e., gender and age) and cigarette smoking behaviour. Analyses revealed that daily caffeine intake was significantly higher for males, older people, participants smoking more cigarettes and showing higher scores on Impulsivity, Sensation Seeking and a facet of Reward Sensitivity. However, more detailed analyses showed that different patterns of individual variables predicted caffeine consumption when the times of day and the caffeine sources were considered. The present results suggest that such detailed analyses are required to detect the critical predictive variables that could be obscured when only total caffeine intake during the entire day is considered. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Variability in the carbon isotope composition of individual amino acids in plant proteins from different sources: 1 Leaves.

    PubMed

    Lynch, Anthony H; Kruger, Nicholas J; Hedges, Robert E M; McCullagh, James S O

    2016-05-01

    The natural carbon isotope composition of individual amino acids from plant leaf proteins has been measured to establish potential sources of variability. The plant leaves studied, taken from a range of plant groups (forbs, trees, grasses, and freshwater aquatic plants), showed no significant influence of either season or environment (water and light availability) on their Δδ(13)C values. Plant groups did, however, differ in carbon isotope composition, although no consistent differences were identified at the species level. A discriminant analysis model was constructed which allowed leaves from (1) nettles, (2) Pooideae, (3) other Poales, (4) trees and (5) freshwater higher plants to be distinguished from each other on the basis of their natural abundance (13)C/(12)C ratios of individual amino acids. Differences in carbon isotope composition are known to be retained, to some extent, in the tissues of their consumers, and hence an understanding of compound-specific variation in (13)C/(12)C fractional abundance in plants has the potential to provide dietary insights of value in archaeological and ecological studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Use of Multiple Data Sources and Individual Case Investigation to Refine Surveillance-Based Estimates of the HIV Care Continuum

    PubMed Central

    Dombrowski, Julia C.; Buskin, Susan E.; Bennett, Amy; Thiede, Hanne; Golden, Matthew R.

    2014-01-01

    Objectives To assess the HIV care continuum among HIV-infected persons residing in Seattle & King County, Washington at the end of 2011 and compare estimates of viral suppression derived from different population-based data sources. Methods We derived estimates for the HIV care continuum using a combination of HIV case and laboratory surveillance data supplemented with individual investigation of cases that appeared to be unlinked to or not retained in HIV care, a jurisdiction-wide population-based retrospective chart review, and local data from the CDC's Medical Monitoring Project and National HIV Behavioral Surveillance. Results Adjusting for in- and out-migration of persons diagnosed with HIV, laboratory surveillance data supplemented with individual case investigation suggest that 67% of persons diagnosed with HIV and 57% of all HIV-infected persons living in King County at the end of 2011 were virally suppressed (plasma HIV RNA <200 copies/mL). The viral suppression estimates we derived from a population-based chart review and adjusted local Medical Monitoring Project data were similar to the surveillance-derived estimate and identical to each other (59% viral suppression among all HIV-infected persons). Conclusions The level of viral suppression in King County is more than twice the national estimate and exceeds estimates of control for other major chronic diseases in the U.S. Our findings suggest that national care continuum estimates may be substantially too pessimistic, and highlight the need to improve HIV surveillance data. PMID:25140904

  1. Variations in the chemical composition of the submicron aerosol and in the sources of the organic fraction at a regional background site of the Po Valley (Italy)

    NASA Astrophysics Data System (ADS)

    Bressi, Michael; Cavalli, Fabrizia; Belis, Claudio A.; Putaud, Jean-Philippe; Fröhlich, Roman; Martins dos Santos, Sebastiao; Petralia, Ettore; Prévôt, André S. H.; Berico, Massimo; Malaguti, Antonella; Canonaco, Francesco

    2016-10-01

    Fine particulate matter (PM) levels and resulting impacts on human health are in the Po Valley (Italy) among the highest in Europe. To build effective PM abatement strategies, it is necessary to characterize fine PM chemical composition, sources and atmospheric processes on long timescales (> months), with short time resolution (< day), and with particular emphasis on the predominant organic fraction. Although previous studies have been conducted in this region, none of them addressed all these aspects together. For the first time in the Po Valley, we investigate the chemical composition of nonrefractory submicron PM (NR-PM1) with a time resolution of 30 min at the regional background site of Ispra during 1 full year, using the Aerodyne Aerosol Chemical Speciation Monitor (ACSM) under the most up-to-date and stringent quality assurance protocol. The identification of the main components of the organic fraction is made using the Multilinear-Engine 2 algorithm implemented within the latest version of the SoFi toolkit. In addition, with the aim of a potential implementation of ACSM measurements in European air quality networks as a replacement of traditional filter-based techniques, parallel multiple offline analyses were carried out to assess the performance of the ACSM in the determination of PM chemical species regulated by air quality directives. The annual NR-PM1 level monitored at the study site (14.2 µg m-3) is among the highest in Europe and is even comparable to levels reported in urban areas like New York City and Tokyo. On the annual basis, submicron particles are primarily composed of organic aerosol (OA, 58 % of NR-PM1). This fraction was apportioned into oxygenated OA (OOA, 66 %), hydrocarbon-like OA (HOA, 11 % of OA) and biomass burning OA (BBOA, 23 %). Among the primary sources of OA, biomass burning (23 %) is thus bigger than fossil fuel combustion (11 %). Significant contributions of aged secondary organic aerosol (OOA) are observed throughout the

  2. Online laser desorption-multiphoton postionization mass spectrometry of individual aerosol particles: molecular source indicators for particles emitted from different traffic-related and wood combustion sources.

    PubMed

    Bente, Matthias; Sklorz, Martin; Streibel, Thorsten; Zimmermann, Ralf

    2008-12-01

    Direct inlet aerosol mass spectrometry plays an increasingly important role in applied and fundamental aerosol and nanoparticle research. Laser desorption/ionization (LDI) based techniques for single particle time-of-flight mass spectrometry (LDI-SP-TOFMS) are a promising approach in the chemical analysis of single aerosol particles, especially for the detection of inorganic species and distinction of particle classes. However, until now the detection of molecular organic compounds on a single particle basis has been difficult due to the high laser power densities which are required for the LDI process as well as due to the inherent matrix effects associated with this ionization technique. By the application of a two-step approach, where an IR desorption laser pulse is applied to perform a gentle desorption of organic material from the single particle surface and a second UV-laser performs the soft ionization of the desorbed species, this drawback of laser based single particles mass spectrometry can be overcome. The postionization of the desorbed molecules has been accomplished in this work by resonance enhanced multiphoton ionization (REMPI) using a KrF excimer laser (248 nm). REMPI allows an almost fragmentation free trace analysis of polycyclic aromatic hydrocarbons (PAHs) and their derivatives from individual single particles (laser desorption-REMPI postionization-single particle-time-of-flight mass spectrometry or LD-REMPI-SP-TOFMS). Crucial system parameters of the home-built aerosol mass spectrometer such as the power densities and the relative timing of both lasers were optimized with respect to the detectability of particle source specific organic signatures using well characterized standard particles. In a second step, the LD-REMPI-SP-TOFMS system was applied to analyze different real world aerosols (spruce wood combustion, gasoline car exhaust, beech wood combustion, and diesel car exhaust). It was possible to distinguish the particles from different

  3. Identification and mapping stripe rust resistance gene YrLM168a using extreme individuals and recessive phenotype class in a complicate genetic background.

    PubMed

    Feng, Junyan; Chen, Guoyue; Wei, Yuming; Liu, Yaxi; Jiang, Qiantao; Li, Wei; Pu, Zhien; Lan, Xiujin; Dai, Shoufen; Zhang, Min; Zheng, Youliang

    2015-12-01

    The identification and characterization of resistance genes effective against stripe rust of wheat is beneficial for modern wheat breeding programs. Molecular markers to such genes facilitate their deployment. The variety Milan has resistance that is effective against the predominant stripe rust races in the Sichuan region. Two resistant and two susceptible F8 lines from a cross between Milan and the susceptible variety Chuannong 16 were used to investigate inheritance of the Milan resistance. Three F2 populations were developed from crosses between the resistant lines and their susceptible sibling lines (LM168a × LM168c, LM168c × LM168a, LM168b × LM168d) and used for genetic analysis and molecular mapping of the genes for resistance. The stripe rust resistance in LM168a and LM168b was conferred by a single dominant gene, temporarily designated as YrLM168a. Forty-five extreme susceptible plants from the F2 families of LM168d × LM168b were genotyped with 836 simple sequence repeat (SSR) markers to map YrLM168a. YrLM168a was mapped in chromosome 6BL. The nearest flanking markers Xwmc756 and Xbarc146 were 4.6 and 4.6 cM away from the gene at both sides, respectively. The amplification results of twenty extreme resistant (IT 0) and susceptible (IT 4) F2 plants of LM168c × LM168a and LM168a × LM168c with marker Xwmc756 further validated the mapping results. The study suggested that extreme individuals and recessive phenotype class can be successfully used for mapping genes, which should be efficient and reliable. In addition, the flanking markers near YrLM168a should be helpful in marker-assisted breeding.

  4. Airborne particulate polycyclic aromatic hydrocarbon (PAH) pollution in a background site in the North China Plain: concentration, size distribution, toxicity and sources.

    PubMed

    Zhu, Yanhong; Yang, Lingxiao; Yuan, Qi; Yan, Chao; Dong, Can; Meng, Chuanping; Sui, Xiao; Yao, Lan; Yang, Fei; Lu, Yaling; Wang, Wenxing

    2014-01-01

    The size-fractionated characteristics of particulate polycyclic aromatic hydrocarbons (PAHs) were studied from January 2011 to October 2011 using a Micro-orifice Uniform Deposit Impactor (MOUDI) at the Yellow River Delta National Nature Reserve (YRDNNR), a background site located in the North China Plain. The average annual concentration of total PAHs in the YRDNNR (18.95 ± 16.51 ng/m(3)) was lower than that in the urban areas of China; however, it was much higher than that in other rural or remote sites in developed countries. The dominant PAHs, which were found in each season, were fluorene (5.93%-26.80%), phenanthrene (8.17%-26.52%), fluoranthene (15.23%-27.12%) and pyrene (9.23%-16.31%). A bimodal distribution was found for 3-ring PAHs with peaks at approximately 1.0-1.8 μm and 3.2-5.6 μm; however, 4-6 ring PAHs followed a nearly unimodal distribution, with the highest peak in the 1.0-1.8 μm range. The mass median diameter (MMD) values for the total PAHs averaged 1.404, 1.467, 1.218 and 0.931 μm in spring, summer, autumn and winter, respectively. The toxicity analysis indicated that the carcinogenic potency of particulate PAHs existed primarily in the <1.8 μm size range. Diagnostic ratios and PCA analysis indicated that the PAHs in aerosol particles were mainly derived from coal combustion. In addition, back-trajectory calculations demonstrated that atmospheric PAHs were produced primarily by local anthropogenic sources.

  5. The impact of the in-orbit background and the X-ray source intensity on the centroiding accuracy of the Swift X-ray telescope

    NASA Astrophysics Data System (ADS)

    Ambrosi, R. M.; Hutchinson, I. B.; Hill, J.; Cheruvu, C.; Abbey, A. F.; Short, A. D. T.

    2002-11-01

    The optical components of the Swift Gamma Ray Burst Explorer X-ray Telescope (XRT), consisting of the JET-X spare flight mirror and a charge coupled device of the type used in the EPIC program, were used in a re-calibration study carried out at the Panter facility, which is part of the Max Plank Institute for Extraterrestrial Physics. The objective of this study was to check the focal length and the off axis performance of the mirrors and to show that the half energy width (HEW) of the on-axis point spread function (PSF) was of the order of 16arcsec at 1.5keV (Nucl. Instr. and Meth. A 488 (2002) 543; SPIE 4140 (2000) 64) and that a centroiding accuracy better that 1arcsec could be achieved within the 4arcmin sampling area designated by the Burst Alert Telescope (Nucl. Instr. and Meth. A 488 (2002) 543). The centroiding accuracy of the Swift XRT's optical components was tested as a function of distance from the focus and off axis position of the PSF (Nucl. Instr. and Meth. A 488 (2002) 543). The presence of background events in the image frame introduced errors in the centroiding process, making the choice of centroiding algorithm important (Nucl. Instr. and Meth. A 488 (2002) 543). Since the objective of Swift is to rapidly investigate the X-ray afterglows of Gamma Ray Bursts the possibility of detecting a bright source with intensity greater than 25 Crab could not be excluded and therefore the impact of a saturated PSF core on the centroiding accuracy was investigated by experimental methods.

  6. Dietary Intake of Individual (Free and Intrinsic) Sugars and Food Sources in the Spanish Population: Findings from the ANIBES Study

    PubMed Central

    Ruiz, Emma; Rodriguez, Paula; Valero, Teresa; Ávila, José M.; Aranceta-Bartrina, Javier; Gil, Ángel; González-Gross, Marcela; Ortega, Rosa M.; Serra-Majem, Lluis; Varela-Moreiras, Gregorio

    2017-01-01

    The consumption of total and individual sugars is controversial and little is known about consumption and dietary sources in Spain. The purpose was to examine free and intrinsic sugar intake and food and beverage sources. The ANIBES Study (Anthropometry, Intake and Energy Balance in Spain), a cross-sectional study of a representative sample of the Spanish population (9–75 years old; n = 2009) carried out in 2013, was used. Food and beverage records were obtained by a three-day dietary record by using a tablet device. The median total sugar intake was 71.5 g/day (17% Total Energy, TE), the intrinsic sugar intake was 38.3 g/day (9.6% TE), and the free sugar was 28.8 g/day (7.3% TE). Total sugar intake (free and intrinsic) was higher in men than in women for all age groups, although in terms of the contribution to total energy intake, the opposite was observed. Differences were observed for free sugar consumption dependent on age and marked differences (up to two-fold) were observed when considering the percent TE, which was much higher in children and adolescents. For the intrinsic sugar, however, a higher contribution to TE was observed in the elderly. The major sources of intrinsic sugars were fruits (31.8%), milks (19.6%), juices and nectars (11.1%), vegetables (9.89%), yogurt and fermented milk (7.18%), low-alcohol-content beverages (4,94%), bread (2.91%), and sugar soft drinks (2.24%), greater than 90% from diet contribution. As for free sugars, sources were sugar soft drinks (25.5%), sugar (17.8%), bakery and pastry items (15.2%), chocolates (11.4%), yogurt and fermented milk (6.44%), other dairy products (5.99%), jams (3.58%), juices and nectars (2.91%), and breakfast cereals and cereal bars (2.78%), summing up to 90% of the contribution. The present study demonstrates that only a moderate percentage of the Spanish population adhered to the present recommendations for total sugar intake, and urgent efforts are needed to improve diet quality in the youngest

  7. Dietary Intake of Individual (Free and Intrinsic) Sugars and Food Sources in the Spanish Population: Findings from the ANIBES Study.

    PubMed

    Ruiz, Emma; Rodriguez, Paula; Valero, Teresa; Ávila, José M; Aranceta-Bartrina, Javier; Gil, Ángel; González-Gross, Marcela; Ortega, Rosa M; Serra-Majem, Lluis; Varela-Moreiras, Gregorio

    2017-03-14

    The consumption of total and individual sugars is controversial and little is known about consumption and dietary sources in Spain. The purpose was to examine free and intrinsic sugar intake and food and beverage sources. The ANIBES Study (Anthropometry, Intake and Energy Balance in Spain), a cross-sectional study of a representative sample of the Spanish population (9-75 years old; n = 2009) carried out in 2013, was used. Food and beverage records were obtained by a three-day dietary record by using a tablet device. The median total sugar intake was 71.5 g/day (17% Total Energy, TE), the intrinsic sugar intake was 38.3 g/day (9.6% TE), and the free sugar was 28.8 g/day (7.3% TE). Total sugar intake (free and intrinsic) was higher in men than in women for all age groups, although in terms of the contribution to total energy intake, the opposite was observed. Differences were observed for free sugar consumption dependent on age and marked differences (up to two-fold) were observed when considering the percent TE, which was much higher in children and adolescents. For the intrinsic sugar, however, a higher contribution to TE was observed in the elderly. The major sources of intrinsic sugars were fruits (31.8%), milks (19.6%), juices and nectars (11.1%), vegetables (9.89%), yogurt and fermented milk (7.18%), low-alcohol-content beverages (4,94%), bread (2.91%), and sugar soft drinks (2.24%), greater than 90% from diet contribution. As for free sugars, sources were sugar soft drinks (25.5%), sugar (17.8%), bakery and pastry items (15.2%), chocolates (11.4%), yogurt and fermented milk (6.44%), other dairy products (5.99%), jams (3.58%), juices and nectars (2.91%), and breakfast cereals and cereal bars (2.78%), summing up to 90% of the contribution. The present study demonstrates that only a moderate percentage of the Spanish population adhered to the present recommendations for total sugar intake, and urgent efforts are needed to improve diet quality in the youngest

  8. Analysis of the Upper Respiratory Tract Microbiotas as the Source of the Lung and Gastric Microbiotas in Healthy Individuals

    PubMed Central

    Bassis, Christine M.; Erb-Downward, John R.; Dickson, Robert P.; Freeman, Christine M.; Schmidt, Thomas M.; Young, Vincent B.; Beck, James M.; Curtis, Jeffrey L.

    2015-01-01

    ABSTRACT No studies have examined the relationships between bacterial communities along sites of the upper aerodigestive tract of an individual subject. Our objective was to perform an intrasubject and intersite analysis to determine the contributions of two upper mucosal sites (mouth and nose) as source communities for the bacterial microbiome of lower sites (lungs and stomach). Oral wash, bronchoalveolar lavage (BAL) fluid, nasal swab, and gastric aspirate samples were collected from 28 healthy subjects. Extensive analysis of controls and serial intrasubject BAL fluid samples demonstrated that sampling of the lungs by bronchoscopy was not confounded by oral microbiome contamination. By quantitative PCR, the oral cavity and stomach contained the highest bacterial signal levels and the nasal cavity and lungs contained much lower levels. Pyrosequencing of 16S rRNA gene amplicon libraries generated from these samples showed that the oral and gastric compartments had the greatest species richness, which was significantly greater in both than the richness measured in the lungs and nasal cavity. The bacterial communities of the lungs were significantly different from those of the mouth, nose, and stomach, while the greatest similarity was between the oral and gastric communities. However, the bacterial communities of healthy lungs shared significant membership with the mouth, but not the nose, and marked subject-subject variation was noted. In summary, microbial immigration from the oral cavity appears to be the significant source of the lung microbiome during health, but unlike the stomach, the lungs exhibit evidence of selective elimination of Prevotella bacteria derived from the upper airways. PMID:25736890

  9. Characterisation of the biochemical methane potential (BMP) of individual material fractions in Danish source-separated organic household waste.

    PubMed

    Naroznova, Irina; Møller, Jacob; Scheutz, Charlotte

    2016-04-01

    This study is dedicated to characterising the chemical composition and biochemical methane potential (BMP) of individual material fractions in untreated Danish source-separated organic household waste (SSOHW). First, data on SSOHW in different countries, available in the literature, were evaluated and then, secondly, laboratory analyses for eight organic material fractions comprising Danish SSOHW were conducted. No data were found in the literature that fully covered the objectives of the present study. Based on laboratory analyses, all fractions were assigned according to their specific properties in relation to BMP, protein content, lipids, lignocellulose biofibres and easily degradable carbohydrates (carbohydrates other than lignocellulose biofibres). The three components in lignocellulose biofibres, i.e. lignin, cellulose and hemicellulose, were differentiated, and theoretical BMP (TBMP) and material degradability (BMP from laboratory incubation tests divided by TBMP) were expressed. Moreover, the degradability of lignocellulose biofibres (the share of volatile lignocellulose biofibre solids degraded in laboratory incubation tests) was calculated. Finally, BMP for average SSOHW composition in Denmark (untreated) was calculated, and the BMP contribution of the individual material fractions was then evaluated. Material fractions of the two general waste types, defined as "food waste" and "fibre-rich waste," were found to be anaerobically degradable with considerable BMP. Material degradability of material fractions such as vegetation waste, moulded fibres, animal straw, dirty paper and dirty cardboard, however, was constrained by lignin content. BMP for overall SSOHW (untreated) was 404 mL CH4 per g VS, which might increase if the relative content of material fractions, such as animal and vegetable food waste, kitchen tissue and dirty paper in the waste, becomes larger.

  10. A simplified approach for solving coagulation-diffusion equation to estimate atmospheric background particle number loading factors contributed by emissions from localized sources

    NASA Astrophysics Data System (ADS)

    Anand, S.; Mayya, Y. S.

    2011-08-01

    Coagulation and condensation/evaporation combined with atmospheric dispersion are the main processes responsible for the evolution of aerosol particle size distributions and number concentrations emitted from localized sources. A crucial question is: what fraction of freshly emitted particles survive intra-coagulation effect to persist in the atmosphere and become available for further interaction with background aerosols?. The difficulty in estimating this quantity, designated as the number survival fraction, arises due chiefly to the joint action of atmospheric diffusion with nonlinear coagulation effects which are computationally intensive to handle. We provide a simplified approach to evaluate this quantity in the context of instantaneous (puff) and continuous (plume) releases based on a reduction of the respective coagulation-diffusion equations under the assumption of a constant coagulation kernel ( K). The condensation/evaporation processes, being number conserving, are not included in the study. The approach consists of constructing moment equations for the evolution of number concentration and variance of the spatial extension of puff or plume in terms of either time or downstream distance. The puff model, applicable to instantaneous releases is solved within a 3-D, spherically symmetric framework, under an additional assumption of a constant diffusion coefficient ( D) which renders itself amenable to a closed form solution that provides a benchmark for developing the solution to the plume model. The latter case, corresponding to continuous releases, is discussed within a 2-D framework under the assumptions of constant advection velocity ( U) and space dependent diffusion coefficient expressed in terms of turbulent energy dissipation rate ( ɛ). The study brings out the special effect of the coagulation-induced flattening of the spatial concentration profiles because of which particle sizes will be larger at the centre of a Gaussian puff. For a puff of

  11. Sources of individual variability: miRNAs that predispose to neuropathic pain identified using genome-wide sequencing

    PubMed Central

    2014-01-01

    Background We carried out a genome-wide study, using microRNA sequencing (miRNA-seq), aimed at identifying miRNAs in primary sensory neurons that are associated with neuropathic pain. Such scans usually yield long lists of transcripts regulated by nerve injury, but not necessarily related to pain. To overcome this we tried a novel search strategy: identification of transcripts regulated differentially by nerve injury in rat lines very similar except for a contrasting pain phenotype. Dorsal root ganglia (DRGs) L4 and 5 in the two lines were excised 3 days after spinal nerve ligation surgery (SNL) and small RNAs were extracted and sequenced. Results We identified 284 mature miRNA species expressed in rat DRGs, including several not previously reported, and 3340 unique small RNA sequences. Baseline expression of miRNA was nearly identical in the two rat lines, consistent with their shared genetic background. In both lines many miRNAs were nominally up- or down-regulated following SNL, but the change was similar across lines. Only 3 miRNAs that were expressed abundantly (rno-miR-30d-5p, rno-miR-125b-5p) or at moderate levels (rno-miR-379-5p) were differentially regulated. This makes them prime candidates as novel PNS determinants of neuropathic pain. The first two are known miRNA regulators of the expression of Tnf, Bdnf and Stat3, gene products intimately associated with neuropathic pain phenotype. A few non-miRNA, small noncoding RNAs (sncRNAs) were also differentially regulated. Conclusions Despite its genome-wide coverage, our search strategy yielded a remarkably short list of neuropathic pain-related miRNAs. As 2 of the 3 are validated regulators of important pro-nociceptive compounds, it is likely that they contribute to the orchestration of gene expression changes that determine individual variability in pain phenotype. Further research is required to determine whether some of the other known or predicted gene targets of these miRNAs, or of the differentially

  12. Selective, but Only if It Is Free: Children Trust Inaccurate Individuals More When Alternative Sources Are Costly

    ERIC Educational Resources Information Center

    Brosseau-Liard, Patricia E.

    2014-01-01

    The present research examines the effect of the costliness of an information source on children's selective learning. In three experiments (total N?=?112), 4-to 7-year-olds were given the opportunity to acquire and endorse information from one of two sources. One source, a computer, was described as always accurate; the other source, a…

  13. Selective, but Only if It Is Free: Children Trust Inaccurate Individuals More When Alternative Sources Are Costly

    ERIC Educational Resources Information Center

    Brosseau-Liard, Patricia E.

    2014-01-01

    The present research examines the effect of the costliness of an information source on children's selective learning. In three experiments (total N?=?112), 4-to 7-year-olds were given the opportunity to acquire and endorse information from one of two sources. One source, a computer, was described as always accurate; the other source, a…

  14. Identify and Quantify the Mechanistic Sources of Sensor Performance Variation Between Individual Sensors SN1 and SN2

    SciTech Connect

    Diaz, Aaron A.; Baldwin, David L.; Cinson, Anthony D.; Jones, Anthony M.; Larche, Michael R.; Mathews, Royce; Mullen, Crystal A.; Pardini, Allan F.; Posakony, Gerald J.; Prowant, Matthew S.; Hartman, Trenton S.; Edwards, Matthew K.

    2014-08-06

    This Technical Letter Report satisfies the M3AR-14PN2301022 milestone, and is focused on identifying and quantifying the mechanistic sources of sensor performance variation between individual, 22-element, linear phased-array sensor prototypes, SN1 and SN2, respectively. This effort constitutes an iterative evolution that supports the longer term goal of producing and demonstrating a pre-manufacturing prototype ultrasonic probe that possesses the fundamental performance characteristics necessary to enable the development of a high-temperature sodium-cooled fast reactor inspection system. The scope of the work for this portion of the PNNL effort conducted in FY14 includes performing a comparative evaluation and assessment of the performance characteristics of the SN1 and SN2 22 element PA-UT probes manufactured at PNNL. Key transducer performance parameters, such as sound field dimensions, resolution capabilities, frequency response, and bandwidth are used as a metric for the comparative evaluation and assessment of the SN1 and SN2 engineering test units.

  15. Hydrogen isotopic composition of individual n-alkanes as an intrinsic tracer for bioremediation and source identification of petroleum contamination.

    PubMed

    Pond, Kristy L; Huang, Yongsong; Wang, Yi; Kulpa, Charles F

    2002-02-15

    The isotopic signatures of crude oil hydrocarbons are potentially powerful intrinsic tracers to their origins and the processes by which the oils are modified in the environment. Stable carbon isotopic data are of limited use for studying petroleum contaminants because of the relatively small amount of isotopic fractionation that occurs during natural processes. Hydrogen isotopes, in contrast, are commonly fractionated to a much greater extent and as a result display larger variations in delta values. We studied the effect of in vitro aerobic biodegradation on the hydrogen isotopic composition of individual n-alkanes from crude oil. The isotopic analysis was conducted using gas chromatography-thermal conversion-isotope ratio mass spectrometry. In general, biodegradation rates decreased with increasing hydrocarbon chain length, consistent with previous studies. More importantly the n-alkanes that were degraded at the fastest rates (n-C15 to n-C18) also showed the largest overall isotopic fractionation (approximately 12-25 per thousand deuterium enrichment), suggesting that the lower molecular weight n-alkanes can be used to monitor in-situ bioremediation of crude oil contamination. The hydrogen isotopic compositions of the longer chain alkanes (n-C19 to n-C27) were relatively stable during biodegradation (<5%o overall deuterium enrichment), indicating that these compounds are effective tracers for oil-source identification studies.

  16. Fungal nutrient allocation in common mycorrhizal networks is regulated by the carbon source strength of individual host plants.

    PubMed

    Fellbaum, Carl R; Mensah, Jerry A; Cloos, Adam J; Strahan, Gary E; Pfeffer, Philip E; Kiers, E Toby; Bücking, Heike

    2014-07-01

    Common mycorrhizal networks (CMNs) of arbuscular mycorrhizal (AM) fungi in the soil simultaneously provide multiple host plants with nutrients, but the mechanisms by which the nutrient transport to individual host plants within one CMN is controlled are unknown. Using radioactive and stable isotopes, we followed the transport of phosphorus (P) and nitrogen (N) in the CMNs of two fungal species to plants that differed in their carbon (C) source strength, and correlated the transport to the expression of mycorrhiza-inducible plant P (MtPt4) and ammonium (1723.m00046) transporters in mycorrhizal roots. AM fungi discriminated between host plants that shared a CMN and preferentially allocated nutrients to high-quality (nonshaded) hosts. However, the fungus also supplied low-quality (shaded) hosts with nutrients and maintained a high colonization rate in these plants. Fungal P transport was correlated to the expression of MtPt4. The expression of the putative ammonium transporter 1723.m00046 was dependent on the fungal nutrient supply and was induced when the CMN had access to N. Biological market theory has emerged as a tool with which the strategic investment of competing partners in trading networks can be studied. Our work demonstrates how fungal partners are able to retain bargaining power, despite being obligately dependent on their hosts.

  17. 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.

  18. Regional Scale Variability in Background and Source δ13C of Methane in the Atlantic, Europe and the Arctic: Cautionary Tales for Isotopic Modeling

    NASA Astrophysics Data System (ADS)

    Lowry, D.; Fisher, R. E.; France, J. L.; Lanoiselle, M.; Zazzeri, G.; Nisbet, E. G.

    2013-12-01

    Modeling studies of methane δ13C, both of modern atmosphere and glacial palaeoclimates have used a global isotopic signature for each of the main source categories, whereas detailed studies of source fluxes, such as boreal wetlands, suggest that on the centimeter to meter scale there is very great variability. In recent years we have been reassessing the usefulness of using a generic source value from source up to regional scale through sampling campaigns in the European Arctic, the UK and onboard ships sailing the Atlantic up to the Arctic Ocean. Currently the boreal wetland source of methane dominates above 60°N. Within Finland this source varies at the wetland scale from -74 to -66‰ depending on wetland type and seasonal variability in temperature and water table. Lapland road trips and ship sampling suggest that these emissions are homogenized to -70 to -67‰ in the well-mixed regional atmosphere. An infrequent boreal forest fire emission adds a -30 to -26‰ component into the mix, and such inputs have been observed in the Mace Head (Ireland) isotopic record of 2002. The story is much more complex once the latitudes of heavily urbanized and agricultural areas of Northern Europe are reached. Isotopic signatures applied to UK and EC inventories suggest that national emissions can vary from -42 to -60‰ depending on source mix, but even this is too simplified. Fugitive emissions from gas distribution systems vary based on the source of the gas, with biogenic-dominated supplies from west Siberia at -50‰ to thermogenic gas of the Southern North Sea fields at -32‰. Coal emissions are also source-dependent and have a similar range to gas, but unlike pipeline-homogenized gas can vary from one mine to the next. Emissions from ruminants vary due to C3 and C4 plant diets, with C4 closer to -50‰ while C3 emissions are in the low -60's. A recent whole barn experiment in the UK recorded -66‰. Landfill signatures also vary. Sites engineered in the last decade

  19. 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.

  20. Sources and formation mechanisms of carbonaceous aerosol at a regional background site in the Netherlands: insights from a year-long radiocarbon study

    NASA Astrophysics Data System (ADS)

    Dusek, Ulrike; Hitzenberger, Regina; Kasper-Giebl, Anne; Kistler, Magdalena; Meijer, Harro A. J.; Szidat, Sönke; Wacker, Lukas; Holzinger, Rupert; Röckmann, Thomas

    2017-03-01

    We measured the radioactive carbon isotope 14C (radiocarbon) in various fractions of the carbonaceous aerosol sampled between February 2011 and March 2012 at the Cesar Observatory in the Netherlands. Based on the radiocarbon content in total carbon (TC), organic carbon (OC), water-insoluble organic carbon (WIOC), and elemental carbon (EC), we estimated the contribution of major sources to the carbonaceous aerosol. The main source categories were fossil fuel combustion, biomass burning, and other contemporary carbon, which is mainly biogenic secondary organic aerosol material (SOA). A clear seasonal variation is seen in EC from biomass burning (ECbb), with lowest values in summer and highest values in winter, but ECbb is a minor fraction of EC in all seasons. WIOC from contemporary sources is highly correlated with ECbb, indicating that biomass burning is a dominant source of contemporary WIOC. This suggests that most biogenic SOA is water soluble and that water-insoluble carbon stems mainly from primary sources. Seasonal variations in other carbon fractions are less clear and hardly distinguishable from variations related to air mass history. Air masses originating from the ocean sector presumably contain little carbonaceous aerosol from outside the Netherlands, and during these conditions measured carbon concentrations reflect regional sources. In these situations absolute TC concentrations are usually rather low, around 1.5 µg m-3, and ECbb is always very low ( ˜ 0.05 µg m-3), even in winter, indicating that biomass burning is not a strong source of carbonaceous aerosol in the Netherlands. In continental air masses, which usually arrive from the east or south and have spent several days over land, TC concentrations are on average by a factor of 3.5 higher. ECbb increases more strongly than TC to 0.2 µg m-3. Fossil EC and fossil WIOC, which are indicative of primary emissions, show a more moderate increase by a factor of 2.5 on average. An interesting case is

  1. Seasonal variability of PM2.5 and PM10 composition and sources in an urban background site in Southern Italy.

    PubMed

    Cesari, D; De Benedetto, G E; Bonasoni, P; Busetto, M; Dinoi, A; Merico, E; Chirizzi, D; Cristofanelli, P; Donateo, A; Grasso, F M; Marinoni, A; Pennetta, A; Contini, D

    2017-08-26

    Comparison of fine and coarse fractions in terms of sources and dynamics is scarce in southeast Mediterranean countries; differences are relevant because of the importance of natural sources like sea spray and Saharan dust advection, because most of the monitoring networks are limited to PM10. In this work, the main seasonal variabilities of sources and processes involving fine and coarse PM (particulate matter) were studied at the Environmental-Climate Observatory of Lecce (Southern Italy). Simultaneous PM2.5 and PM10 samples were collected between July 2013 and July 2014 and chemically analysed to determine concentrations of several species: OC (organic carbon) and EC (elemental carbon) via thermo-optical analysis, 9 major ions via IC, and 23 metals via ICP-MS. Data was processed through mass closure analysis and Positive Matrix Factorization (PMF) receptor model characterizing seasonal variabilities of nine sources contributions. Organic and inorganic secondary aerosol accounts for 43% of PM2.5 and 12% of PM2.5-10 with small seasonal changes. SIA (secondary inorganic aerosol) seasonal pattern is opposite to that of SOC (secondary organic carbon). SOC is larger during the cold period, sulphate (the major contributor to SIA) is larger during summer. Two forms of nitrate were identified: NaNO3, correlated with chloride depletion and aging of sea-spray, mainly present in PM2.5-10; NH4NO3 more abundant in PM2.5. Biomass burning is a relevant source with larger contribution during autumn and winter because of the influence of domestic heating, however, is not negligible in spring and summer, because of the contributions of fires and agricultural practices. Mass closure analysis and PMF results identify two soil sources: crustal associated to long range transport and carbonates associated to local resuspended dust. Both sources contributes to the coarse fraction and have different dynamics with crustal source contributing mainly in high winds from SE conditions and

  2. A comparison of the cosmic microwave and cosmic X-ray backgrounds - Constraints on local sources of the fluctuations observed by COBE

    NASA Technical Reports Server (NTRS)

    Boughn, S. P.; Jahoda, K.

    1993-01-01

    It has been suggested by Hogan (1992) that the microwave background anisotropy detected by the COBE DMR experiment (Smoot et al., 1992) might be produced by inverse Compton scattering from hot diffuse clouds of electrons in nearby superclusters. If the COBE fluctuations are due to this mechanism, then the absence of anticorrelations between maps of the cosmic microwave and cosmic X-ray backgrounds constrains the temperature (16 keV) and density (less than 2 x 10 exp -6/cu cm) of the ionized supercluster gas. Since the COBE limits on spectral distortion indicate that the temperature of the intergalactic medium is less than 10 keV, we conclude that the fluctuations observed by COBE are probably not produced by this mechanism.

  3. Dietary Sodium Intakes and Food Sources of Sodium in Canadian-Born and Asian-Born Individuals of Chinese Ethnicity at a Canadian University Campus

    ERIC Educational Resources Information Center

    Yu, Yan Han; Farmer, Anna; Mager, Diana; Willows, Noreen

    2014-01-01

    Objective: To document the sodium intake and food sources of sodium of Canadian-born Chinese (CBC) and Asian-born Chinese (ABC) individuals at a Canadian university campus. Participants: Healthy adults aged 18-58 years originating from Canada, China, Hong Kong, or Taiwan were recruited from the University of Alberta (n = 40 CBC, n = 41 ABC)…

  4. Dietary Sodium Intakes and Food Sources of Sodium in Canadian-Born and Asian-Born Individuals of Chinese Ethnicity at a Canadian University Campus

    ERIC Educational Resources Information Center

    Yu, Yan Han; Farmer, Anna; Mager, Diana; Willows, Noreen

    2014-01-01

    Objective: To document the sodium intake and food sources of sodium of Canadian-born Chinese (CBC) and Asian-born Chinese (ABC) individuals at a Canadian university campus. Participants: Healthy adults aged 18-58 years originating from Canada, China, Hong Kong, or Taiwan were recruited from the University of Alberta (n = 40 CBC, n = 41 ABC)…

  5. Bayesian Nitrate Source Apportionment to Individual Groundwater Wells in the Central Valley by use of Nitrogen, Oxygen, and Boron Isotopic Tracers

    NASA Astrophysics Data System (ADS)

    Lockhart, K.; Harter, T.; Grote, M.; Young, M. B.; Eppich, G.; Deinhart, A.; Wimpenny, J.; Yin, Q. Z.

    2014-12-01

    Groundwater quality is a concern in alluvial aquifers underlying agricultural areas worldwide, an example of which is the San Joaquin Valley, California. Nitrate from land applied fertilizers or from animal waste can leach to groundwater and contaminate drinking water resources. Dairy manure and synthetic fertilizers are the major sources of nitrate in groundwater in the San Joaquin Valley, however, septic waste can be a major source in some areas. As in other such regions around the world, the rural population in the San Joaquin Valley relies almost exclusively on shallow domestic wells (≤150 m deep), of which many have been affected by nitrate. Consumption of water containing nitrate above the drinking water limit has been linked to major health effects including low blood oxygen in infants and certain cancers. Knowledge of the proportion of each of the three main nitrate sources (manure, synthetic fertilizer, and septic waste) contributing to individual well nitrate can aid future regulatory decisions. Nitrogen, oxygen, and boron isotopes can be used as tracers to differentiate between the three main nitrate sources. Mixing models quantify the proportional contributions of sources to a mixture by using the concentration of conservative tracers within each source as a source signature. Deterministic mixing models are common, but do not allow for variability in the tracer source concentration or overlap of tracer concentrations between sources. Bayesian statistics used in conjunction with mixing models can incorporate variability in the source signature. We developed a Bayesian mixing model on a pilot network of 32 private domestic wells in the San Joaquin Valley for which nitrate as well as nitrogen, oxygen, and boron isotopes were measured. Probability distributions for nitrogen, oxygen, and boron isotope source signatures for manure, fertilizer, and septic waste were compiled from the literature and from a previous groundwater monitoring project on several

  6. The chemical composition of tropospheric aerosols and their contributing sources to a continental background site in northern Zimbabwe from 1994 to 2000

    NASA Astrophysics Data System (ADS)

    Nyanganyura, Daniel; Maenhaut, Willy; Mathuthu, Manny; Makarau, Amos; Meixner, Franz X.

    Atmospheric aerosols were collected in separate coarse (2-10 μm diameter) and fine (diameter less than 2 μm) size fractions at Rukomechi Research Station (16.1°S, 29.4°E), Zimbabwe, in the central part of southern Africa, from September 1994 to January 2000. The samples were analysed for the particulate mass (PM), black carbon, and 47 elements. The overall data set and the separate wet and dry season data sets were examined with absolute principal component analysis (APCA). Natural and anthropogenic aerosol sources were identified in both seasons, but the sources and their contributions to the total PM were found to vary between seasons and between size fractions. Crustal matter, sea salt (SS), a mixed biogenic (BIO) emission/biomass burning (BB) component, and a copper component were identified for the coarse aerosols during the wet season. APCA attributed 29% of the total wet season coarse PM to the mixed BIO/BB component, and 32% to SS. The copper component is likely due to the copper smelters in the Zambian Copperbelt. The dry season coarse PM originated from crustal matter, BB, BIO, and SS sources, with the major contribution (32%) coming from BB. Four components (crustal matter, BB, non-ferrous smelters, and SS) were identified for the fine particles for both the wet and dry seasons. The BB component provided the major contribution to the total fine PM, accounting for 44% and 79% in the wet and dry seasons, respectively. The relative contributions to the total PM (both fine and coarse) for all sources were greater in the dry season than the wet season, except for SS.

  7. Abnormal cortical sources of resting state electroencephalographic rhythms in single treatment-naïve HIV individuals: A statistical z-score index.

    PubMed

    Babiloni, Claudio; Pennica, Alfredo; Del Percio, Claudio; Noce, Giuseppe; Cordone, Susanna; Muratori, Chiara; Ferracuti, Stefano; Donato, Nicole; Di Campli, Francesco; Gianserra, Laura; Teti, Elisabetta; Aceti, Antonio; Soricelli, Andrea; Viscione, Magdalena; Limatola, Cristina; Andreoni, Massimo; Onorati, Paolo

    2016-03-01

    This study tested a simple statistical procedure to recognize single treatment-naïve HIV individuals having abnormal cortical sources of resting state delta (<4 Hz) and alpha (8-13 Hz) electroencephalographic (EEG) rhythms with reference to a control group of sex-, age-, and education-matched healthy individuals. Compared to the HIV individuals with a statistically normal EEG marker, those with abnormal values were expected to show worse cognitive status. Resting state eyes-closed EEG data were recorded in 82 treatment-naïve HIV (39.8 ys.±1.2 standard error mean, SE) and 59 age-matched cognitively healthy subjects (39 ys.±2.2 SE). Low-resolution brain electromagnetic tomography (LORETA) estimated delta and alpha sources in frontal, central, temporal, parietal, and occipital cortical regions. Ratio of the activity of parietal delta and high-frequency alpha sources (EEG marker) showed the maximum difference between the healthy and the treatment-naïve HIV group. Z-score of the EEG marker was statistically abnormal in 47.6% of treatment-naïve HIV individuals with reference to the healthy group (p<0.05). Compared to the HIV individuals with a statistically normal EEG marker, those with abnormal values exhibited lower mini mental state evaluation (MMSE) score, higher CD4 count, and lower viral load (p<0.05). This statistical procedure permitted for the first time to identify single treatment-naïve HIV individuals having abnormal EEG activity. This procedure might enrich the detection and monitoring of effects of HIV on brain function in single treatment-naïve HIV individuals. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  8. Background reduction by a getter pump around the ionization volume of a Lamb-shift polarimeter and possible improvements of polarized ion sources

    SciTech Connect

    Engels, R.; Emmerich, R.; Grigoryev, K.; Paetz gen Schieck, H.; Ley, J.; Mikirtychyants, M.; Rathmann, F.; Sarkadi, J.; Seyfarth, H.; Tenckhoff, G.; Vasilyev, A.

    2005-05-15

    The Koeln-Juelich Lamb-shift polarimeter is used to measure the nuclear polarization of the hydrogen or deuterium beam produced with the atomic-beam source for the polarized target at the ANKE spectrometer at COSY-Juelich. The precision of the earlier results had been dominated by the recombination of atoms in the ionizer. Protons or deuterons from the dissociative ionization of unpolarized recombined H{sub 2} or D{sub 2} molecules had strongly contributed to the extracted ion beam. To suppress this effect, in the new ionizer a nonevaporable getter pump of about 2000 l/s H{sub 2} or D{sub 2} pumping speed surrounds the ionization volume. It reduces the extracted current of unpolarized ions, produced from the recombined molecular gas, by a factor of about 20 compared with the earlier value, which reduces the error of the polarization measurements to about 0.5%. Now the H{sub 2} or D{sub 2} molecules in the ionization volume predominantly are those which are contained in the incoming beam from the atomic beam source. This allows the measurement of the fraction of unpolarized molecules in the polarized atomic H-vector or D-vector beam. The improvement achieved is a valuable step toward the measurement of the nuclear polarization of a gas sample, extracted from the storage cell of the polarized internal gas target for the spectrometer ANKE in the COSY-Juelich storage ring with the Lamb-shift polarimeter. Furthermore, the results show that the polarization of proton or deuteron beams would be increased by the installation of such a pump around the ionization volume of atomic-beam ion sources with an electron-impact ionizer. For ECR ionizers the recombined H{sub 2} or D{sub 2} molecules would be absorbed, whereas the noble gases, used as buffer, are not pumped by the getter material.

  9. Temperature Measurement of a Miniature Ceramic Heater in the Presence of an Extended Interfering Background Radiation Source Using a Multiwavelength Pyrometer

    NASA Technical Reports Server (NTRS)

    Ng, Daniel

    1999-01-01

    Temperature measurement of small (millimeter size) objects is generally difficult and demanding. Measurement involving ceramic materials using the traditional one- and two-color pyrometer is difficult because of their complex optical properties, such as low emissivity which may vary with both temperature and wavelength. Pyrometry applications in an environment with an interfering radiation source of extended dimension adds extra complexity to the process. We show that the multiwavelength pyrometer successfully measured the temperatures of a millimeter (mm) size ceramic heater under these demanding conditions.

  10. Fungal nutrient allocation in common mycorrhizal networks is regulated by the carbon source strength of individual host plants

    USDA-ARS?s Scientific Manuscript database

    • The common mycorrhizal networks (CMN) of arbuscular mycorrhizal (AM) fungi in the soil provide multiple host plants with nutrients, but the mechanisms by which the nutrient transport to individual host plants within one CMN is controlled, are currently unknown. • We followed by radioactive and st...

  11. Sources of Individual Differences in L2 Narrative Production: The Contribution of Input, Processing, and Output Anxiety

    ERIC Educational Resources Information Center

    Trebits, Anna

    2016-01-01

    The aim of this study was to investigate the effects of cognitive task complexity and individual differences in input, processing, and output anxiety (IPOA) on L2 narrative production. The participants were enrolled in a bilingual secondary educational program. They performed two narrative tasks in speech and writing. The participants' level of…

  12. Sources of Individual Differences in L2 Narrative Production: The Contribution of Input, Processing, and Output Anxiety

    ERIC Educational Resources Information Center

    Trebits, Anna

    2016-01-01

    The aim of this study was to investigate the effects of cognitive task complexity and individual differences in input, processing, and output anxiety (IPOA) on L2 narrative production. The participants were enrolled in a bilingual secondary educational program. They performed two narrative tasks in speech and writing. The participants' level of…

  13. Primordial non-Gaussianity with μ-type and y-type spectral distortions: exploiting Cosmic Microwave Background polarization and dealing with secondary sources

    NASA Astrophysics Data System (ADS)

    Ravenni, Andrea; Liguori, Michele; Bartolo, Nicola; Shiraishi, Maresuke

    2017-09-01

    Cross-correlations between Cosmic Microwave Background (CMB) temperature and y-spectral distortion anisotropies have been previously proposed as a way to measure the local bispectrum parameter fNLloc. in a range of scales inaccessible to either CMB (T, E) bispectra or μ T correlations. This is useful e.g. to test scale dependence of primordial non-Gaussianity. Unfortunately, the primordial y T signal is strongly contaminated by the late-time correlation between the Integrated Sachs Wolfe and Sunyaev-Zel'dovich (SZ) effects. Moreover, SZ itself generates a large noise contribution in the y-parameter map. We consider two original ways to address these issues. In order to remove the bias due to the SZ-CMB temperature coupling, while also providing additional signal, we include in the analysis the cross-correlation between y-distortions and CMB polarization. In order to reduce the noise, we propose to clean the y-map by subtracting a SZ template, reconstructed via cross-correlation with external tracers (CMB and galaxy-lensing signals). We combine this SZ template subtraction with the previously suggested solution of directly masking detected clusters. Our final forecasts show that, using y-distortions, a PRISM-like survey can achieve 1σ(fNLloc.) = 300, while an ideal experiment will achieve 1σ(fNLloc.) = 130 with improvements of a factor between 2.1 and 3.8, depending on the considered survey, from adding the y E signal, and a further 20–30 % from template cleaning. These forecasts are much worse than current fNLloc. boundaries from Planck, but we stress that they refer to completely different scales.

  14. Sources of self-categorization as minority for mixed-race individuals: Implications for affirmative action entitlement.

    PubMed

    Good, Jessica J; Chavez, George F; Sanchez, Diana T

    2010-10-01

    Multiracial individuals are in the unique position of being able to categorize themselves as members of multiple racial groups. Drawing on self-categorization theory, we suggest that similarity to the minority ingroup depends on self-perceptions of physical appearance and connectedness to the minority ingroup. Moreover, we argue that similarity to the ingroup determines self-categorization as minority, which predicts category-based entitlements such as perceived eligibility for minority resources (e.g., affirmative action). Using path analysis, we found support for this model on a convenience sample of 107 mixed-race minority-White participants. The results suggest that affective processes rather than observable characteristics such as prototypical physical appearance better predict self-categorization among mixed-race individuals. PsycINFO Database Record (c) 2010 APA, all rights reserved

  15. Formation of manganese nanoclusters in a sputtering/aggregation source and the roles of individual operating parameters

    NASA Astrophysics Data System (ADS)

    Khojasteh, Malak; Kresin, Vitaly V.

    2016-12-01

    We describe the production of size selected manganese nanoclusters using a dc magnetron sputtering/aggregation source. Since nanoparticle production is sensitive to a range of overlapping operating parameters (in particular, the sputtering discharge power, the inert gas flow rates, and the aggregation length) we focus on a detailed map of the influence of each parameter on the average nanocluster size. In this way it is possible to identify the main contribution of each parameter to the physical processes taking place within the source. The discharge power and argon flow supply the atomic vapor, and argon also plays the crucial role in the formation of condensation nuclei via three-body collisions. However, neither the argon flow nor the discharge power have a strong effect on the average nanocluster size in the exiting beam. Here the defining role is played by the source residence time, which is governed by the helium supply and the aggregation path length. The size of mass selected nanoclusters was verified by atomic force microscopy of deposited particles.

  16. A spatial individual-based model predicting a great impact of copious sugar sources and resting sites on survival of Anopheles gambiae and malaria parasite transmission.

    PubMed

    Zhu, Lin; Qualls, Whitney A; Marshall, John M; Arheart, Kris L; DeAngelis, Donald L; McManus, John W; Traore, Sekou F; Doumbia, Seydou; Schlein, Yosef; Müller, Günter C; Beier, John C

    2015-02-05

    Agent-based modelling (ABM) has been used to simulate mosquito life cycles and to evaluate vector control applications. However, most models lack sugar-feeding and resting behaviours or are based on mathematical equations lacking individual level randomness and spatial components of mosquito life. Here, a spatial individual-based model (IBM) incorporating sugar-feeding and resting behaviours of the malaria vector Anopheles gambiae was developed to estimate the impact of environmental sugar sources and resting sites on survival and biting behaviour. A spatial IBM containing An. gambiae mosquitoes and humans, as well as the village environment of houses, sugar sources, resting sites and larval habitat sites was developed. Anopheles gambiae behaviour rules were attributed at each step of the IBM: resting, host seeking, sugar feeding and breeding. Each step represented one second of time, and each simulation was set to run for 60 days and repeated 50 times. Scenarios of different densities and spatial distributions of sugar sources and outdoor resting sites were simulated and compared. When the number of natural sugar sources was increased from 0 to 100 while the number of resting sites was held constant, mean daily survival rate increased from 2.5% to 85.1% for males and from 2.5% to 94.5% for females, mean human biting rate increased from 0 to 0.94 bites per human per day, and mean daily abundance increased from 1 to 477 for males and from 1 to 1,428 for females. When the number of outdoor resting sites was increased from 0 to 50 while the number of sugar sources was held constant, mean daily survival rate increased from 77.3% to 84.3% for males and from 86.7% to 93.9% for females, mean human biting rate increased from 0 to 0.52 bites per human per day, and mean daily abundance increased from 62 to 349 for males and from 257 to 1120 for females. All increases were significant (P < 0.01). Survival was greater when sugar sources were randomly distributed in the whole

  17. Workflow for high-content, individual cell quantification of fluorescent markers from universal microscope data, supported by open source software.

    PubMed

    Stockwell, Simon R; Mittnacht, Sibylle

    2014-12-16

    Advances in understanding the control mechanisms governing the behavior of cells in adherent mammalian tissue culture models are becoming increasingly dependent on modes of single-cell analysis. Methods which deliver composite data reflecting the mean values of biomarkers from cell populations risk losing subpopulation dynamics that reflect the heterogeneity of the studied biological system. In keeping with this, traditional approaches are being replaced by, or supported with, more sophisticated forms of cellular assay developed to allow assessment by high-content microscopy. These assays potentially generate large numbers of images of fluorescent biomarkers, which enabled by accompanying proprietary software packages, allows for multi-parametric measurements per cell. However, the relatively high capital costs and overspecialization of many of these devices have prevented their accessibility to many investigators. Described here is a universally applicable workflow for the quantification of multiple fluorescent marker intensities from specific subcellular regions of individual cells suitable for use with images from most fluorescent microscopes. Key to this workflow is the implementation of the freely available Cell Profiler software(1) to distinguish individual cells in these images, segment them into defined subcellular regions and deliver fluorescence marker intensity values specific to these regions. The extraction of individual cell intensity values from image data is the central purpose of this workflow and will be illustrated with the analysis of control data from a siRNA screen for G1 checkpoint regulators in adherent human cells. However, the workflow presented here can be applied to analysis of data from other means of cell perturbation (e.g., compound screens) and other forms of fluorescence based cellular markers and thus should be useful for a wide range of laboratories.

  18. Soy and legume seeds as sources of isoflavones: selected individual determinants of their consumption in a group of perimenopausal women

    PubMed Central

    2014-01-01

    The aim of this study The aim of this study was to analyze selected individual determinants of consumption of soy products and legumes by menopausal women. The analyzed individual characteristics included the level of general self-efficacy, optimism, and satisfaction with life. The study, using a questionnaire for the assessment of food product consumption frequency, and psychological tests (GSES, LOT-R, SWLS), was conducted in a group of 320 women aged between 45 and 55 years. Spearman's coefficient of rank correlation and the Kruskal-Wallis test with the Dunn test for multiple comparisons were used for statistical analysis (p < 0.05). Material and methods The analyzed 45-55-year-old women consumed legume seeds several times a month on average, while the frequency of soy/soy product consumption was lower than once a month. Statistical analysis revealed that the frequency of soy product consumption increased with the level of self-efficacy, optimism and satisfaction with life (p < 0.01). Also the increased frequency of legume seed consumption was associated with higher level of optimism and satisfaction with life (p < 0.01). Results Intergroup comparisons of the average consumption frequency of these products confirmed that legume seeds were significantly more frequently chosen by women characterized by high rather than low levels of optimism (3.36 vs. 2.62, p < 0.001) and satisfaction with life (3.36 vs. 2.65, p < 0.01). Also soy products were preferred significantly more often by women with higher levels of optimism (2.00 vs. 1.38, p < 0.05) and satisfaction with life (2.02 vs. 1.39, p < 0.05). Conclusions The consumption of legume seeds, and especially soy products, was revealed to be very low among perimenopausal women, and varied depending on the analyzed individual traits, with a tendency to more frequent ingestion by individuals with higher levels of self-efficacy, optimism, and satisfaction with life. PMID:26327825

  19. Three-coil inductively coupled plasma (ICP) source with individually controlled coil currents supplied from a single power generator

    NASA Astrophysics Data System (ADS)

    Dorf, Leonid; Rauf, Shahid; Liu, Jonathan; Kenney, Jason; Lane, Steven; Nguyen, Andrew; Ramaswamy, Kartik; Collins, Ken

    2013-09-01

    As requirements on plasma uniformity get more stringent in the semiconductor industry, an ICP source with 3 coils becomes warranted. Designing a power distribution/50 Ω-tuning network (PDN) that delivers the power from a single generator to 3 coils is complicated, due to inductive coupling between the coils, and between coils and plasma. Our PDN comprises several capacitors, including 2 variable ones, C1,2, connected in parallel to 2 coils. A set of equations for coils/plasma currents was solved over a wide parameter space to determine practical values/ranges for all capacitors. It was shown that by moving along a pre-determined programming path in C1,2 space, one can attain various coil current ratios (CCR) without crossing resonance curves. The latter causes coil current reversal, which may result in plasma instabilities and affect uniformity. Based on modeling results, the PDN was built and tested using a specially made 3-coil source. A wide range of CCR was achieved by varying C1,2, including maxima or minima in any 2 coils. With slight adjustments (to account for parasitics and actual plasma coupling), the model correctly predicted experimentally observed CCR for each tested C1,2 pair. Likewise, the theoretical resonance structure was reproduced experimentally with good agreement.

  20. 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…

  1. Small-scale fluctuations and angular correlations of the X-ray background in the HEAO 1 A-2 energy band - Constraints on clustering of X-ray sources

    NASA Technical Reports Server (NTRS)

    Martin-Mirones, J. M.; De Zotti, G.; Franceschini, A.; Boldt, E. A.; Marshall, F. E.; Danese, L.; Persic, M.

    1991-01-01

    HEAO 1 A-2 all-sky survey data have been used to determine the amplitude of intensity fluctuations of the extragalactic 2-10 keV X-ray background (XRB) over an effective solid angle of 1.84 sq deg and their angular correlation function on angular scales of less than 3 deg. A good empirical fit to the data is obtained assuming that the integral counts in the A-2 band have a slope of 1.65 + 0.06 or - 0.07. Alternatively, the data may imply a significant clustering of extragalactic X-ray sources.

  2. Treatment-naive individuals are the major source of transmitted HIV-1 drug resistance in men who have sex with men in the Swiss HIV Cohort Study.

    PubMed

    Drescher, Sara M; von Wyl, Viktor; Yang, Wan-Lin; Böni, Jürg; Yerly, Sabine; Shah, Cyril; Aubert, Vincent; Klimkait, Thomas; Taffé, Patrick; Furrer, Hansjakob; Battegay, Manuel; Ambrosioni, Juan; Cavassini, Matthias; Bernasconi, Enos; Vernazza, Pietro L; Ledergerber, Bruno; Günthard, Huldrych F; Kouyos, Roger D

    2014-01-01

    Human immunodeficiency virus type 1 (HIV-1) transmitted drug resistance (TDR) can compromise antiretroviral therapy (ART) and thus represents an important public health concern. Typically, sources of TDR remain unknown, but they can be characterized with molecular epidemiologic approaches. We used the highly representative Swiss HIV Cohort Study (SHCS) and linked drug resistance database (SHCS-DRDB) to analyze sources of TDR. ART-naive men who have sex with men with infection date estimates between 1996 and 2009 were chosen for surveillance of TDR in HIV-1 subtype B (N = 1674), as the SHCS-DRDB contains pre-ART genotypic resistance tests for >69% of this surveillance population. A phylogeny was inferred using pol sequences from surveillance patients and all subtype B sequences from the SHCS-DRDB (6934 additional patients). Potential sources of TDR were identified based on phylogenetic clustering, shared resistance mutations, genetic distance, and estimated infection dates. One hundred forty of 1674 (8.4%) surveillance patients carried virus with TDR; 86 of 140 (61.4%) were assigned to clusters. Potential sources of TDR were found for 50 of 86 (58.1%) of these patients. ART-naive patients constitute 56 of 66 (84.8%) potential sources and were significantly overrepresented among sources (odds ratio, 6.43 [95% confidence interval, 3.22-12.82]; P < .001). Particularly large transmission clusters were observed for the L90M mutation, and the spread of L90M continued even after the near cessation of antiretroviral use selecting for that mutation. Three clusters showed evidence of reversion of K103N or T215Y/F. Many individuals harboring viral TDR belonged to transmission clusters with other Swiss patients, indicating substantial domestic transmission of TDR in Switzerland. Most TDR in clusters could be linked to sources, indicating good surveillance of TDR in the SHCS-DRDB. Most TDR sources were ART naive. This, and the presence of long TDR transmission chains, suggests

  3. Investigating the source of hepatitis C virus infection among individuals whose route of infection is undefined: a study of ten cases.

    PubMed

    Roy, Kirsty M; Goldberg, David; Taylor, Avril; Mills, Peter

    2003-01-01

    Hepatitis C virus (HCV) transmission is predominantly parenteral via infected blood products or shared injecting equipment. Many infected individuals, however, deny these risk factors. This study set out to determine whether an in-depth interview would determine the likely source of infection for those whose route of infection was undefined. Between May 1999 and July 1999, risk factor information was sought, through in-depth interview, from 10 patients whose source of hepatitis C infection was undefined. The clinical notes of the patients were scrutinized to complement the information provided through the questionnaire. Despite undertaking an in-depth interview, it was not possible to establish the likely route of infection for 9 of the 10 individuals studied as they reported several risk events. There is little benefit to interviewing routinely those HCV-infected people who have no history of injecting drugs or having received a contaminated blood/blood product transfusion, to ascertain their likely source or time of infection; at best, such effort might only increase one's confidence that infection was acquired through means other than these 2 routes.

  4. 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.

  5. Properties and sources of individual particles and some chemical species in the aerosol of a metropolitan underground railway station

    NASA Astrophysics Data System (ADS)

    Salma, Imre; Pósfai, Mihály; Kovács, Kristóf; Kuzmann, Ernő; Homonnay, Zoltán; Posta, József

    Aerosol samples in PM 10-2.0 and PM 2.0 size fractions were collected on the platform of a metropolitan underground railway station in central Budapest. Individual aerosol particles were studied using atomic force microscopy, scanning electron microscopy and transmission electron microscopy with energy-dispersive X-ray spectrometry and electron diffraction. The bulk aerosol samples were investigated by 57Fe Mössbauer spectroscopy, and they were subjected to chemical speciation analysis for Cr. The particles were classified into groups of iron oxides and iron, carbonates, silicates, quartz and carbonaceous debris. Electron micrographs showed that the Fe-rich particles in the PM 2.0 size fraction typically consisted of aggregates of nano-sized hematite crystals that were randomly oriented, had round shapes and diameters of 5-15 nm. In addition to hematite, a minor fraction of the iron oxide particles also contained magnetite. In addition, the PM 2.0-fraction particles typically had a rugged surface with layered or granular morphologies. Mössbauer spectroscopy suggested that hematite was a major Fe-bearing species in the PM 10-2.0 size fraction; its mass contribution to the Fe was 36%. Further constituents (ferrite, carbides and FeOOH) were also identified. The water soluble amounts of Cr for the underground railway station and city center were similar. In the PM 10-2.0 size fraction, practically all dissolved Cr had an oxidation state of three, which corresponds to ambient conditions. In the PM 2.0 size fraction, however, approximately 7% of the dissolved Cr was present as Cr(VI), which was different from that for the urban aerosol. It is suggested that the increased adverse health effects of aerosol particles in metros with respect to ambient outdoor particles is linked to the differences in the oxidation states, surface properties or morphologies.

  6. Sources of variation in innate immunity in great tit nestlings living along a metal pollution gradient: an individual-based approach.

    PubMed

    Vermeulen, Anke; Müller, Wendt; Matson, Kevin D; Tieleman, B Irene; Bervoets, Lieven; Eens, Marcel

    2015-03-01

    Excessive deposition of metals in the environment is a well-known example of pollution worldwide. Chronic exposure of organisms to metals can have a detrimental effect on reproduction, behavior, health and survival, due to the negative effects on components of the immune system. However, little is known about the effects of chronic sublethal metal exposure on immunity, especially for wildlife. In our study, we examined the constitutive innate immunity of great tit (Parus major) nestlings (N=234) living in four populations along a metal pollution gradient. For each nestling, we determined the individual metal concentrations (lead, cadmium, arsenic) present in the red blood cells and measured four different innate immune parameters (agglutination, lysis, haptoglobin concentrations and nitric oxide concentrations) to investigate the relationship between metal exposure and immunological condition. While we found significant differences in endogenous metal concentrations among populations with the highest concentrations closest to the pollution source, we did not observe corresponding patterns in our immune measures. However, when evaluating relationships between metal concentrations and immune parameters at the individual level, we found negative effects of lead and, to a lesser extent, arsenic and cadmium on lysis. In addition, high arsenic concentrations appear to elicit inflammation, as reflected by elevated haptoglobin concentrations. Thus despite the lack of a geographic association between pollution and immunity, this type of association was present at the individual level at a very early life stage. The high variation in metal concentrations and immune measures observed within populations indicates a high level of heterogeneity along an existing pollution gradient. Interestingly, we also found substantial within nest variation, for which the sources remain unclear, and which highlights the need of an individual-based approach. Copyright © 2014 Elsevier B.V. All

  7. Background Perchlorate Source Identification Technical Guidance

    DTIC Science & Technology

    2013-12-01

    on results generated using the U.S. Army Corps of Engineers’ Hydrologic Modeling System , a computer program designed to simulate the precipitation... System at each approach end as well as lighted carrier deck landing areas at both ends so pilots can simulate carrier landings. NAF-El Centro is the...K. W. Edwards, 1976. “ Methods for Determination of Radioactive Substances in Water and Fluvial Sediments .” In Techniques of Water-Resources

  8. Effects of background noise on total noise annoyance

    NASA Technical Reports Server (NTRS)

    Willshire, K. F.

    1987-01-01

    Two experiments were conducted to assess the effects of combined community noise sources on annoyance. The first experiment baseline relationships between annoyance and noise level for three community noise sources (jet aircraft flyovers, traffic and air conditioners) presented individually. Forty eight subjects evaluated the annoyance of each noise source presented at four different noise levels. Results indicated the slope of the linear relationship between annoyance and noise level for the traffic noise was significantly different from that of aircraft and of air conditioner noise, which had equal slopes. The second experiment investigated annoyance response to combined noise sources, with aircraft noise defined as the major noise source and traffic and air conditioner noise as background noise sources. Effects on annoyance of noise level differences between aircraft and background noise for three total noise levels and for both background noise sources were determined. A total of 216 subjects were required to make either total or source specific annoyance judgements, or a combination of the two, for a wide range of combined noise conditions.

  9. Individual particles of cryoconite deposited on the mountain glaciers of the Tibetan Plateau: Insights into chemical composition and sources

    NASA Astrophysics Data System (ADS)

    Dong, Zhiwen; Qin, Dahe; Kang, Shichang; Liu, Yajun; Li, Yang; Huang, Jie; Qin, Xiang

    2016-08-01

    Cryoconite deposited on mountain glacier surfaces is significant for understanding regional atmospheric environments, which could influence the albedo and energy balance of the glacier basins, and maintain the glacial microbiology system. Field observations were conducted on the glaciers of western China, including Laohugou Glacier No.12 (LHG), Tanggula Dongkemadi Glacier (TGL), Zhadang Glacier (ZD), and Baishui Glacier No.1 in the Yulong Mountains (YL), as well as Urumqi Glacier No.1 in the Tianshan Mountains (TS) for comparison with locations in the Tibetan Plateau, in addition to laboratory TEM-EDX analysis of the individual cryoconite particles filtered on lacey carbon (LC) and calcium-coated carbon (Ca-C) TEM grids. This work provided information on the morphology and chemical composition, as well as a unique record of the particle's physical state, of cryoconite deposition on the Tibetan Plateau. The result showed that there is a large difference in the cryoconite particle composition between various locations on the Tibetan Plateau. In total, mineral dust particles were dominant (>50%) in the cryoconite at all locations. However, more anthropogenic particles (e.g., black carbon (BC) and fly ash) were found in YL (38%) and ZD (22%) in the Ca-C grids in the southern locations. In TGL, many NaCl and MCS particles (>10%), as well as few BC and biological particles (<5%), were found in cryoconite in addition to mineral dust. In TS, the cryoconite is composed primarily of mineral dust, as well as BC (<5%). Compared with other sites, the LHG cryoconite shows a more complex composition of atmospheric deposition with sufficient NaCl, BC, fly ash and biological particles (6% in LC grid). The higher ratio of anthropogenic particles in the southern Tibetan Plateau is likely caused by atmospheric pollutant transport from the south Asia to the Tibetan Plateau. Cryoconite in the northern locations (e.g., TGL, LHG, and TS) with higher dust and salt particle ratio are

  10. Evaluation of the organic matter sources using the δ13C composition of individual n-alkanes in sediments from Brazilian estuarine systems by GC/C/IRMS

    NASA Astrophysics Data System (ADS)

    Maioli, Otávio Luiz Gusso; de Oliveira, Cristiane Rossi; Dal Sasso, Marco Aurélio; Madureira, Luiz Augusto dos Santos; Azevedo, Débora de Almeida; de Aquino Neto, Francisco Radler

    2012-12-01

    The δ13C composition of individual n-alkanes (from C16 to C34) was measured from surface sediments of five Brazilian estuarine systems affected by different organic matter sources, such as harbor area, industries, urban centers and sugar cane crops, in order to determine the origins of the organic matter. The aliphatic hydrocarbon fraction was analyzed by gas chromatography-combustion-isotope ratio mass spectrometry (GC/C/IRMS). The levels of n-alkanes in the studied areas ranged from 0.34 to 18.14 μg kg-1, being relatively low in comparison to high polluted environments. The Carbon Preference Index (CPI) calculated in the C23-C34 range indicates that n-alkanes are mainly inherited from cuticular waxes of higher plants. The δ13C composition of all n-alkanes detected in the sediment samples ranged from -39.6 to -18.3‰ showing different sources for the studied estuarine systems. Through Principal Component Analysis (PCA) it was possible to verify the petrogenic influence in the n-alkane sources, especially in the Paraíba do Sul sediment samples. Differences up to 15‰ of the δ13C values between n-alkanes of odd and even carbon number (C26 and C27) also indicated mixture of petrogenic and biogenic sources in Paraíba do Sul River. High (less negative) δ13C n-alkane values of odd carbon number were obtained from two sampling sites located close to an ethanol plant, indicating residues discharge of sugar cane (C4 plant). Influence of C3 plants that are the main components of dense ombrophile forest was observed in the Itajaí-Açu sediments by the decrease of δ13C (about 10‰ compared to the Paraíba do Sul River δ13C).

  11. Correction of structured molecular background by means of high-resolution continuum source electrothermal atomic absorption spectrometry--determination of antimony in sediment reference materials using direct solid sampling.

    PubMed

    Araujo, Rennan G O; Welz, Bernhard; Vignola, Fabiola; Becker-Ross, Helmut

    2009-12-15

    A simple, fast and accurate procedure is proposed for the determination of antimony in certified sediment reference materials using direct solid sampling high-resolution continuum source electrothermal atomic absorption spectrometry and iridium as a permanent modifier. The less sensitive resonance line at 231.147 nm has been used in order to allow the introduction of larger sample mass. Six certified reference materials, one river, one estuarine and four marine sediments have been analyzed. The use of iridium as a permanent modifier caused an increase of 30% in sensitivity and stabilized antimony in the sediment to a pyrolysis temperature of 1100 degrees C. Significant background absorption with pronounced rotational fine structure was observed at the optimum atomization temperature of 2100 degrees C, which coincided with the analyte atomic absorption in time. This background was found to be due to the electron excitation spectra of mostly the SiO and in part the PO molecules, and could be eliminated by applying a least-squares background correction algorithm. A characteristic mass of 28 pg Sb was obtained, and the limit of detection (3sigma, n=10) was 0.02 microg g(-1), calculated for 0.2 mg of sample. The results obtained for six certified reference materials with concentrations between 0.40 and 11.6+/-2.6 microg g(-1) Sb were in agreement with the certified values according to a Student's t-test for a 95% confidence level, using aqueous standards for calibration. The precision, expressed as relative standard deviation, ranged between 7% and 17% (n=5).

  12. 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

  13. 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.

  14. The Individual and Ethnic Identity: An Evaluation Report.

    ERIC Educational Resources Information Center

    Brownstein, Henry H.; And Others

    An evaluation of a student sourcebook which contains quotations of 51 individuals from varying ethnic backgrounds and with varying degrees of ethnicity is reported. The primary objective of the source book is to illustrate that people who identify with ethnic groups are individuals and not merely members of the group. Separate sections of the…

  15. Molecular Individual-Based Approach on Triatoma brasiliensis: Inferences on Triatomine Foci, Trypanosoma cruzi Natural Infection Prevalence, Parasite Diversity and Feeding Sources.

    PubMed

    Almeida, Carlos Eduardo; Faucher, Leslie; Lavina, Morgane; Costa, Jane; Harry, Myriam

    2016-02-01

    We used an individual-based molecular multisource approach to assess the epidemiological importance of Triatoma brasiliensis collected in distinct sites and ecotopes in Rio Grande do Norte State, Brazil. In the semi-arid zones of Brazil, this blood sucking bug is the most important vector of Trypanosoma cruzi--the parasite that causes Chagas disease. First, cytochrome b (cytb) and microsatellite markers were used for inferences on the genetic structure of five populations (108 bugs). Second, we determined the natural T. cruzi infection prevalence and parasite diversity in 126 bugs by amplifying a mini-exon gene from triatomine gut contents. Third, we identified the natural feeding sources of 60 T. brasiliensis by using the blood meal content via vertebrate cytb analysis. Demographic inferences based on cytb variation indicated expansion events in some sylvatic and domiciliary populations. Microsatellite results indicated gene flow between sylvatic and anthropic (domiciliary and peridomiciliary) populations, which threatens vector control efforts because sylvatic population are uncontrollable. A high natural T. cruzi infection prevalence (52-71%) and two parasite lineages were found for the sylvatic foci, in which 68% of bugs had fed on Kerodon rupestris (Rodentia: Caviidae), highlighting it as a potential reservoir. For peridomiciliary bugs, Galea spixii (Rodentia: Caviidae) was the main mammal feeding source, which may reinforce previous concerns about the potential of this animal to link the sylvatic and domiciliary T. cruzi cycles.

  16. Human-Induced Pluripotent Stem Cell-Derived Mesenchymal Stem Cells as an Individual-Specific and Renewable Source of Adult Stem Cells.

    PubMed

    Sequiera, Glen Lester; Saravanan, Sekaran; Dhingra, Sanjiv

    2017-01-01

    This chapter deals with the employment of human-induced pluripotent stem cells (hiPSCs) as a candidate to differentiate into mesenchymal stem cells (MSCs). This would enable to help establish a regular source of human MSCs with the aim of avoiding the problems associated with procuring the MSCs either from different healthy individuals or patients, limited extraction potentials, batch-to-batch variations or from diverse sources such as bone marrow or adipose tissue. The procedures described herein allow for a guided and ensured approach for the regular maintenance of hiPSCs and their subsequent differentiation into MSCs using the prescribed medium. Subsequently, an easy protocol for the successive isolation and purification of the hiPSC-differentiated MSCs is outlined, which is carried out through passaging and can be further sorted through flow cytometry. Further, the maintenance and expansion of the resultant hiPSC-differentiated MSCs using appropriate characterization techniques, i.e., Reverse-transcription PCR and immunostaining is also elaborated. The course of action has been deliberated keeping in mind the awareness and the requisites available to even beginner researchers who mostly have access to regular consumables and medium components found in the general laboratory.

  17. Molecular Individual-Based Approach on Triatoma brasiliensis: Inferences on Triatomine Foci, Trypanosoma cruzi Natural Infection Prevalence, Parasite Diversity and Feeding Sources

    PubMed Central

    Almeida, Carlos Eduardo; Faucher, Leslie; Lavina, Morgane; Costa, Jane; Harry, Myriam

    2016-01-01

    We used an individual-based molecular multisource approach to assess the epidemiological importance of Triatoma brasiliensis collected in distinct sites and ecotopes in Rio Grande do Norte State, Brazil. In the semi-arid zones of Brazil, this blood sucking bug is the most important vector of Trypanosoma cruzi—the parasite that causes Chagas disease. First, cytochrome b (cytb) and microsatellite markers were used for inferences on the genetic structure of five populations (108 bugs). Second, we determined the natural T. cruzi infection prevalence and parasite diversity in 126 bugs by amplifying a mini-exon gene from triatomine gut contents. Third, we identified the natural feeding sources of 60 T. brasiliensis by using the blood meal content via vertebrate cytb analysis. Demographic inferences based on cytb variation indicated expansion events in some sylvatic and domiciliary populations. Microsatellite results indicated gene flow between sylvatic and anthropic (domiciliary and peridomiciliary) populations, which threatens vector control efforts because sylvatic population are uncontrollable. A high natural T. cruzi infection prevalence (52–71%) and two parasite lineages were found for the sylvatic foci, in which 68% of bugs had fed on Kerodon rupestris (Rodentia: Caviidae), highlighting it as a potential reservoir. For peridomiciliary bugs, Galea spixii (Rodentia: Caviidae) was the main mammal feeding source, which may reinforce previous concerns about the potential of this animal to link the sylvatic and domiciliary T. cruzi cycles. PMID:26891047

  18. Dietary sodium intakes and food sources of sodium in Canadian-born and Asian-born individuals of Chinese ethnicity at a Canadian university campus.

    PubMed

    Yu, Yan Han; Farmer, Anna; Mager, Diana; Willows, Noreen

    2014-01-01

    To document the sodium intake and food sources of sodium of Canadian-born Chinese (CBC) and Asian-born Chinese (ABC) individuals at a Canadian university campus. Healthy adults aged 18-58 years originating from Canada, China, Hong Kong, or Taiwan were recruited from the University of Alberta (n=40 CBC, n=41 ABC) between May and December 2010. Two in-person multipass 24-hour dietary recall interviews were administered for 1 weekday and 1 weekend day. The mean sodium intake was 3,623±1,406 mg/day. The major food sources of sodium were commercially prepared and processed foods for both CBC and ABC (59.9% and 54.7% of sodium, respectively). Condiments contributed substantially to dietary sodium intake of CBC and ABC (27.8% and 35.1% of sodium, respectively). Efforts to reduce dietary sodium among students and other adults of Chinese ethnicity should focus on limiting consumption of commercially processed foods and moderation in discretionary use of salt and soy sauce.

  19. 2. 8--0. 57 Ga individual detrital zircons from carboniferous rocks of the Ouachita orogen, Arkansas: A northern or southern source

    SciTech Connect

    Hutson, F.E.; Walker, N.W.; Land, L.S. . Dept. of Geological Sciences); Sutton, S.J. . Dept. of Earth Resources)

    1993-02-01

    The Late Paleozoic Ouachita orogen developed in response to collision of the North American craton with an unknown, now rifted, land mass. Rocks of the orogen are composed chiefly of synorogenic sediments that were imbricated in northwest vergent thrust sheets. In order to address the question of ages of source rocks, the dated individual zircons from turbiditic sandstones of the Mississippian Stanley Group and from the Pennsylvanian Atoka Formation. The samples are fine-grained, poorly sorted sublitharenites composed of subrounded quartz, plagioclase, untwinned feldspar, white mica, zircon, titanite, and epidote. Lithic fragments include shale, slate, phyllite, and chert. The heterogeneous color and morphology of extracted zircons implies derivation from multiple sources and their subrounded to well-rounded character suggests a multicycle history. Zircon U-Pb ages are concordant to moderately discordant. Stanley Group zircons are 0.57, 0.59, 0.92, 0.93, 1.73, and 2.81 Ga whereas those from the Atoka Formation are 1.03, 1.06, 1.08, 1.32, 1.74, 2.50, and 2.75 Ga. These ages are comparable to known U-Pb ages of the North American basement. The authors note, however, the absence of 1.35--1.40 Ga zircon ages that characterize the midcontinent Granite-Rhyolite terrain. The range of zircon ages is not inconsistent with derivation from Central American and South American sources, but the lack of well-constrained basement ages in these regions preclude direct correlations.

  20. Background subtraction and transient timing with Bayesian Blocks

    NASA Astrophysics Data System (ADS)

    Worpel, H.; Schwope, A. D.

    2015-06-01

    Aims: We aim to incorporate background subtraction into the Bayesian Blocks algorithm so that transient events can be timed accurately and precisely even in the presence of a substantial, rapidly variable background. Methods: We developed several modifications to the algorithm and tested them on a simulated XMM-Newton observation of a bursting and eclipsing object. Results: We found that bursts can be found to good precision for almost all background-subtraction methods, but eclipse ingresses and egresses present problems for most methods. We found one method that recovered these events with precision comparable to the interval between individual photons, in which both source- and background-region photons are combined into a single list and weighted according to the exposure area. We also found that adjusting the Bayesian Blocks change points nearer to blocks with higher count rate removes a systematic bias towards blocks of low count rate.

  1. 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…

  2. Effect of different precursors on generation of reference spectra for structural molecular background correction by solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry: Determination of antimony in cosmetics.

    PubMed

    Barros, Ariane Isis; Victor de Babos, Diego; Ferreira, Edilene Cristina; Gomes Neto, José Anchieta

    2016-12-01

    Different precursors were evaluated for the generation of reference spectra and correction of the background caused by SiO molecules in the determination of Sb in facial cosmetics by high-resolution continuum source graphite furnace atomic absorption spectrometry employing direct solid sample analysis. Zeolite and mica were the most effective precursors for background correction during Sb determination using the 217.581nm and 231.147nm lines. Full 2(3) factorial design and central composite design were used to optimize the atomizer temperature program. The optimum pyrolysis and atomization temperatures were 1500 and 2100°C, respectively. A Pd(NO3)2/Mg(NO3)2 mixture was employed as the chemical modifier, and calibration was performed at 217.581nm with aqueous standards containing Sb in the range 0.5-2.25ng, resulting in a correlation coefficient of 0.9995 and a slope of 0.1548s ng(-1). The sample mass was in the range 0.15-0.25mg. The accuracy of the method was determined by analysis of Montana Soil (II) certified reference material, together with addition/recovery tests. The Sb concentration found was in agreement with the certified value, at a 95% confidence level (paired t-test). Recoveries of Sb added to the samples were in the range 82-108%. The limit of quantification was 0.9mgkg(-1) and the relative standard deviation (n=3) ranged from 0.5% to 7.1%. From thirteen analyzed samples, Sb was not detected in ten samples (blush, eye shadow and compact powder); three samples (two blush and one eye shadow) presented Sb concentration in the 9.1-14.5mgkg(-1) range.

  3. 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.

  4. 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).

  5. 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.

  6. On the social background of the most prominent astronomers of the 20th century - a sociological analysis of the Source Book of Astronomy and Astrophysics. (German Title: Über die soziale Herkunft der bedeutenden Astronomen des 20. Jahrhunderts - Eine soziologische Analyse des Source Book of Astronomy and Astrophysics )

    NASA Astrophysics Data System (ADS)

    Herrmann, Dieter B.

    2011-08-01

    The study investigates the social background of the most successful astronomers, astrophysicists and physicists of the 20th century. The basis for the assessment of their importance was made on grounds of their work in the "Source book of Astronomy and Astrophysics 1900-1975". The data collected presents the social situation of 202 protagonists at the time of the beginning of their career. It was gathered from relevant biographic dictionaries as well as from personal interviews. The social classification follows the "three-layers model" by Engel, Blackwell and Kellat. As a result it becomes apparent that most of the extraordinary astronomers have their roots in the upper middle class.

  7. Dietary intake and food sources of whole grains among US children and adolescents: data from the 1994-1996 Continuing Survey of Food Intakes by Individuals.

    PubMed

    Harnack, Lisa; Walters, Shelley-Ann H; Jacobs, David R

    2003-08-01

    This study characterizes whole grain consumption among a nationally representative sample of US children and adolescents. Data used in this study were collected as part of the 1994-1996 US Department of Agriculture Continuing Survey of Food Intakes by Individuals (CSFII). CSFII was designed to obtain a nationally representative sample of noninstitutionalized persons of all ages residing in the United States. Analyses reported in this article are limited to participants aged 2 to 18 years with two days of dietary recall data (n=4,802). Foods reported in the survey were quantified in servings as defined by the Food Guide Pyramid using the US Department of Agriculture Pyramid Servings Database, which contains reference data for each food reported in CSFII in servings per 100 g for 30 Pyramid food groups, including whole grain and total grain. Means, frequencies, and logistic regression analyses were conducted as appropriate. Average whole grain intake ranged from 0.8 servings per day for preschool-aged children to 1.0 servings per day for adolescents. Ready-to-eat cereals, corn and other chips, and yeast breads were found to be the major food sources of whole grains accounting for 30.9%, 21.7%, and 18.1% of whole grain intake respectively among those aged two to 18 years. Given the apparent low level of whole grain intake among most children and adolescents in the United States, interventions are needed to increase intake of whole-grain foods.

  8. 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

  9. Constraints on the noble gas composition of the Icelandic plume source by laser analyses of individual vesicles in the volcanic glass DICE 11

    NASA Astrophysics Data System (ADS)

    Colin, A. P.; Moreira, M. A.; Gautheron, C.; Burnard, P.

    2014-12-01

    obtained on individual vesicles represent the mantle source values, not contaminated by air, we can precisely correct the Ne isotopic analyses obtained by crushing from air contamination; the corrected values are consistent with the value of neon-B, i.e. favour the hypothesis that the neon in OIB has an irradiated meteorite origin rather than purely solar.

  10. 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.

  11. 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

  12. 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)

  13. 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)

  14. 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.

  15. Correlators in nontrivial backgrounds

    SciTech Connect

    Mello Koch, Robert de; Ives, Norman; Stephanou, Michael

    2009-01-15

    Operators in N=4 super Yang-Mills theory with an R-charge of O(N{sup 2}) are dual to backgrounds which are asymtotically AdS{sub 5}xS{sup 5}. In this article we develop efficient techniques that allow the computation of correlation functions in these backgrounds. We find that (i) contractions between fields in the string words and fields in the operator creating the background are the field theory accounting of the new geometry, (ii) correlation functions of probes in these backgrounds are given by the free field theory contractions but with rescaled propagators and (iii) in these backgrounds there are no open string excitations with their special end point interactions; we have only closed string excitations.

  16. The EPIC-MOS Particle-Induced Background Spectrum

    NASA Technical Reports Server (NTRS)

    Kuntz, K. D.; Snowden, S. L.

    2006-01-01

    We have developed a method for constructing a spectrum of the particle-induced instrumental background of the XMM-Newton EPIC MOS detectors that can be used for observations of the diffuse background and extended sources that fill a significant fraction of the instrument field of view. The strength and spectrum of the particle-induced background, that is, the background due to the interaction of particles with the detector and the detector surroundings, is temporally variable as well as spatially variable over individual chips. Our method uses a combination of the filter-wheel-closed data and a database of unexposed-region data to construct a spectrum of the "quiescent" background. We show that, using this method of background subtraction, the differences between independent observations of the same region of "blank sky" are consistent with the statistical uncertainties except when there is clear evidence of solar wind charge exchange emission. We use the blank sky observations to show that contamination by SWCX emission is a strong function of the solar wind proton flux, and that observations through the flanks of the magnetosheath appear to be contaminated only at much higher solar wind fluxes. We have also developed a spectral model of the residual soft proton flares, which allows their effects to be removed to a substantial degree during spectral fitting.

  17. 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.

  18. 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).

  19. 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.

  20. 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.

  1. 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...

  2. 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...

  3. 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...

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. Contribution of quasar-driven outflows to the extragalactic gamma-ray background

    NASA Astrophysics Data System (ADS)

    Wang, Xiawei; Loeb, Abraham

    2016-12-01

    The origin of the extragalactic γ-ray background permeating throughout the Universe remains a mystery forty years after its discovery. The extrapolated population of blazars can account for only half of the background radiation in the energy range of ~0.1-10 GeV (refs ,). Here we show that quasar-driven outflows generate relativistic protons that produce the missing component of the extragalactic γ-ray background and naturally match its spectral fingerprint, with a generic break above ~1 GeV. The associated γ-ray sources are too faint to be detected individually, explaining why they had not been identified so far. However, future radio observations may image their shock fronts directly. Our best fit to the Fermi-LAT observations of the extragalactic γ-ray background spectrum provides constraints on the outflow parameters that agree with observations of these outflows and theoretical predictions. Although our model explains the data, there might be additional contributing sources.

  10. Conducting Source Water Assessments

    EPA Pesticide Factsheets

    This page presents background information on the source water assessment steps, the four steps of a source wter assessment, and how to use the results of an assessment to protect drinking water sources.

  11. THE INDIVIDUAL, SOCIETY AND SEX. BACKGROUND READINGS FOR SEX EDUCATORS.

    ERIC Educational Resources Information Center

    BRODERICK, CARLFRED B.; AND OTHERS

    THIS BOOK IS DESIGNED AS A TEXT PRIMARILY FOR COLLEGE STUDENTS PREPARING TO TEACH SEX EDUCATION OR "EDUCATION IN THE NATURE OF HUMAN SEXUALITY AND THE RELATIONS BETWEEN THE SEXES" IN ELEMENTARY AND SECONDARY SCHOOLS. AN ATTEMPT IS MADE BY THE 13 WRITERS, MOST OF THEM SOCIOLOGISTS OR PSYCHOLOGISTS, TO DISTINGUISH BETWEEN THE KNOWLEDGE WHICH THE…

  12. Criminal History Background Checks on Individuals in Child Care Services

    DTIC Science & Technology

    1993-01-19

    subsection (aX1). by striking out Ś manths after the date of enactaent of this chater , and no additional staW and insertirig in lieu thenf "May 29, 1991...those-equivalent in’scope to checks conducted on- U.S. citizens: a. Host-government law enforcement and security agency -hecks at the city , State...for form Criminal Records Division Name Check State Highway Patrol Department of Public S3fety COMM: 314-751-3313 P.O. Box 568 Jefferson City , MO

  13. 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.

  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. Berkeley Low Background Facility

    NASA Astrophysics Data System (ADS)

    Thomas, K. J.; Smith, A. R.; Poon, A. W. P.; Chan, Y. D.; Norman, E. B.; Lesko, K. T.

    2015-08-01

    The Berkeley Low Background Facility (BLBF) at Lawrence Berkeley National Laboratory (LBNL) in Berkeley, California provides low background gamma spectroscopy services to a wide array of experiments and projects. The analysis of samples takes place within two unique facilities; locally within a carefully-constructed, low background laboratory on the surface at LBNL and at the Sanford Underground Research Facility (SURF) in Lead, SD. These facilities provide a variety of gamma spectroscopy services to low background experiments primarily in the form of passive material screening for primordial radioisotopes (U, Th, K) or common cosmogenic/anthropogenic products; active screening via neutron activation analysis for U,Th, and K as well as a variety of stable isotopes; and neutron flux/beam characterization measurements through the use of monitors. A general overview of the facilities, services, and sensitivities will be presented. Recent activities and upgrades will also be described including an overview of the recently installed counting system at SURF (recently relocated from Oroville, CA in 2014), the installation of a second underground counting station at SURF in 2015, and future plans. The BLBF is open to any users for counting services or collaboration on a wide variety of experiments and projects.

  18. Building Background Knowledge

    ERIC Educational Resources Information Center

    Fisher, Douglas; Ross, Donna; Grant, Maria

    2010-01-01

    Too often, students enter our classrooms with insufficient knowledge of physical science. As a result, they have a difficult time understanding content in texts, lectures, and laboratory activities. This lack of background knowledge can have an impact on their ability to ask questions and wonder--both key components of inquiry. In this article,…

  19. Berkeley Low Background Facility

    SciTech Connect

    Thomas, K. J.; Norman, E. B.; Smith, A. R.; Poon, A. W. P.; Chan, Y. D.; Lesko, K. T.

    2015-08-17

    The Berkeley Low Background Facility (BLBF) at Lawrence Berkeley National Laboratory (LBNL) in Berkeley, California provides low background gamma spectroscopy services to a wide array of experiments and projects. The analysis of samples takes place within two unique facilities; locally within a carefully-constructed, low background laboratory on the surface at LBNL and at the Sanford Underground Research Facility (SURF) in Lead, SD. These facilities provide a variety of gamma spectroscopy services to low background experiments primarily in the form of passive material screening for primordial radioisotopes (U, Th, K) or common cosmogenic/anthropogenic products; active screening via neutron activation analysis for U,Th, and K as well as a variety of stable isotopes; and neutron flux/beam characterization measurements through the use of monitors. A general overview of the facilities, services, and sensitivities will be presented. Recent activities and upgrades will also be described including an overview of the recently installed counting system at SURF (recently relocated from Oroville, CA in 2014), the installation of a second underground counting station at SURF in 2015, and future plans. The BLBF is open to any users for counting services or collaboration on a wide variety of experiments and projects.

  20. Nonthermal cosmic neutrino background

    NASA Astrophysics Data System (ADS)

    Chen, Mu-Chun; Ratz, Michael; Trautner, Andreas

    2015-12-01

    We point out that, for Dirac neutrinos, in addition to the standard thermal cosmic neutrino background (C ν B ), there could also exist a nonthermal neutrino background with comparable number density. As the right-handed components are essentially decoupled from the thermal bath of standard model particles, relic neutrinos with a nonthermal distribution may exist until today. The relic density of the nonthermal (nt) background can be constrained by the usual observational bounds on the effective number of massless degrees of freedom Neff and can be as large as nν nt≲0.5 nγ. In particular, Neff can be larger than 3.046 in the absence of any exotic states. Nonthermal relic neutrinos constitute an irreducible contribution to the detection of the C ν B and, hence, may be discovered by future experiments such as PTOLEMY. We also present a scenario of chaotic inflation in which a nonthermal background can naturally be generated by inflationary preheating. The nonthermal relic neutrinos, thus, may constitute a novel window into the very early Universe.

  1. Foregrounding the Background.

    ERIC Educational Resources Information Center

    Robbins, Bruce

    1998-01-01

    Argues that when introductory activities to the classics begin with background information, it can upstage or confine the life of the story, and shows little faith in the students as readers or in the literature itself. Suggests sometimes letting the literature begin, and then helping students make sense of it. Discusses examples from "To Kill a…

  2. China: Background Notes Series.

    ERIC Educational Resources Information Center

    Reams, Joanne Reppert

    Concise background information on the People's Republic of China is provided. The publication begins with a profile of the country, outlining the people, geography, economy, and membership in international organizations. The bulk of the document then discusses in more detail China's people, geography, history, government, education, economy, and…

  3. Building Background Knowledge

    ERIC Educational Resources Information Center

    Fisher, Douglas; Ross, Donna; Grant, Maria

    2010-01-01

    Too often, students enter our classrooms with insufficient knowledge of physical science. As a result, they have a difficult time understanding content in texts, lectures, and laboratory activities. This lack of background knowledge can have an impact on their ability to ask questions and wonder--both key components of inquiry. In this article,…

  4. 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.

  5. INDOOR AND OUTDOOR SOURCE CONTRIBUTIONS TO PERSONAL PM2.5 FOR A PANEL OF INDIVIDUALS WITH CARDIOVASCULAR DISEASE OR COPD LIVING IN BOSTON, MA

    EPA Science Inventory

    Repeated personal, home indoor, home outdoor, and ambient particulate and gaseous pollutant levels were characterized for individuals with cardiovascular disease or COPD and their partners living in the Boston area. Health status was determined by self-reported history of myoc...

  6. INDOOR AND OUTDOOR SOURCE CONTRIBUTIONS TO PERSONAL PM2.5 FOR A PANEL OF INDIVIDUALS WITH CARDIOVASCULAR DISEASE OR COPD LIVING IN BOSTON, MA

    EPA Science Inventory

    Repeated personal, home indoor, home outdoor, and ambient particulate and gaseous pollutant levels were characterized for individuals with cardiovascular disease or COPD and their partners living in the Boston area. Health status was determined by self-reported history of myoc...

  7. Sources of organic carbon for Rimicaris hybisae: Tracing individual fatty acids at two hydrothermal vent fields in the Mid-Cayman rise

    NASA Astrophysics Data System (ADS)

    Streit, Kathrin; Bennett, Sarah A.; Van Dover, Cindy L.; Coleman, Max

    2015-06-01

    Hydrothermal vents harbor ecosystems mostly decoupled from organic carbon synthesized with the energy of sunlight (photosynthetic carbon source) but fueled instead by oxidation of reduced compounds to generate a chemosynthetic carbon source. Our study aimed to disentangle photosynthetic and chemosynthetic organic carbon sources for the shrimp species Rimicaris hybisae, a primary consumer presumed to obtain its organic carbon mainly from ectosymbiotic chemoautotrophic bacteria living on its gill cover membrane. To provide ectosymbionts with ideal conditions for chemosynthesis, these shrimp live in dense clusters around vent chimneys; they are, however, also found sparsely distributed adjacent to diffuse vent flows, where they might depend on alternative food sources. Densely and sparsely distributed shrimp were sampled and dissected into abdominal tissue and gill cover membrane, covered with ectosymbiotic bacteria, at two hydrothermal vent fields in the Mid-Cayman rise that differ in vent chemistry. Fatty acids (FA) were extracted from shrimp tissues and their carbon isotopic compositions assessed. The FA data indicate that adult R. hybisae predominantly rely on bacteria for their organic carbon needs. Their FA composition is dominated by common bacterial FA of the n7 family (~41%). Bacterial FA of the n4 FA family are also abundant and found to constitute good biomarkers for gill ectosymbionts. Sparsely distributed shrimp contain fractions of n4 FA in gill cover membranes ~4% lower than densely packed ones (~18%) and much higher fractions of photosynthetic FA in abdominal tissues, ~4% more (compared with 1.6%), suggesting replacement of ectosymbionts along with exoskeletons (molt), while they take up alternative diets of partly photosynthetic organic carbon. Abdominal tissues also contain photosynthetic FA from a second source taken up presumably during an early dispersal phase and still present to c. 3% in adult shrimp. The contribution of photosynthetic carbon to

  8. 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

  9. Chemical Signals of Critical Zone Processing: Quantification of Water and Sediment Sources During Individual Storm Events in the Christina River Critical Zone Observatory

    NASA Astrophysics Data System (ADS)

    Karwan, D. L.; Aufdenkampe, A. K.; Aalto, R. E.; Lazareva, O.; Marquard, J.; Pizzuto, J. E.; Sawyer, A. H.

    2014-12-01

    Chemical signals of water and materials in catchment exports have long been studied as proxies for within-watershed processing. In the Christina River Critical Zone Observatory, we use the chemistry of water, in particular the oxygen-18 and chloride concentrations, and hydrograph separation to evaluate the contributions of different water sources to the stream discharge during a series of five storm events in 2011 and 2012. These events varied in magnitude, from 44 to 168 mm total precipitation, and precipitation chemistry, with δ18O values ranging from -5.38 to -11.06 ‰. The contribution of old water during the storm peak, determined by isotope hydrograph separation, varied from 0% in a spring storm of annual magnitude to 76% during Hurricane Sandy. Soil moisture data, available for all but one of our storms, indicates higher old water contribution at peak flow when the catchment has higher antecedent soil moisture. Understanding differences in water sourcing to the stream during different events provides a basis on which we analyze the movement of critical zone processing with regard to erosion and the source of exported sediment. For example, sediment fingerprinting with fallout radioisotopes indicated variation in sediment source between events. For example, suspended sediment samples taken during Hurricane Irene (28 August 2011) contained between 0 and 11.4 Bq/kg cesium-137 (137Cs) and 175 - 698 Bq/kg of beryllium-7 (7Be), indicating some level of recent surface erosion. Suspended sediment samples taken during Hurricane Sandy (29 October 2012) did not contain measureable activities of either 137Cs or 7Be.

  10. 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.

  11. 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.

  12. 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

  13. Direct comparison of the impact of head tracking, reverberation, and individualized head-related transfer functions on the spatial perception of a virtual speech source

    NASA Technical Reports Server (NTRS)

    Begault, D. R.; Wenzel, E. M.; Anderson, M. R.

    2001-01-01

    A study of sound localization performance was conducted using headphone-delivered virtual speech stimuli, rendered via HRTF-based acoustic auralization software and hardware, and blocked-meatus HRTF measurements. The independent variables were chosen to evaluate commonly held assumptions in the literature regarding improved localization: inclusion of head tracking, individualized HRTFs, and early and diffuse reflections. Significant effects were found for azimuth and elevation error, reversal rates, and externalization.

  14. Direct comparison of the impact of head tracking, reverberation, and individualized head-related transfer functions on the spatial perception of a virtual speech source

    NASA Technical Reports Server (NTRS)

    Begault, D. R.; Wenzel, E. M.; Anderson, M. R.

    2001-01-01

    A study of sound localization performance was conducted using headphone-delivered virtual speech stimuli, rendered via HRTF-based acoustic auralization software and hardware, and blocked-meatus HRTF measurements. The independent variables were chosen to evaluate commonly held assumptions in the literature regarding improved localization: inclusion of head tracking, individualized HRTFs, and early and diffuse reflections. Significant effects were found for azimuth and elevation error, reversal rates, and externalization.

  15. Direct comparison of the impact of head tracking, reverberation, and individualized head-related transfer functions on the spatial perception of a virtual speech source.

    PubMed

    Begault, D R; Wenzel, E M; Anderson, M R

    2001-10-01

    A study of sound localization performance was conducted using headphone-delivered virtual speech stimuli, rendered via HRTF-based acoustic auralization software and hardware, and blocked-meatus HRTF measurements. The independent variables were chosen to evaluate commonly held assumptions in the literature regarding improved localization: inclusion of head tracking, individualized HRTFs, and early and diffuse reflections. Significant effects were found for azimuth and elevation error, reversal rates, and externalization.

  16. Ontogenetic de novo copy number variations (CNVs) as a source of genetic individuality: studies on two families with MZD twins for schizophrenia.

    PubMed

    Maiti, Sujit; Kumar, Kiran Halagur Bhoge Gowda; Castellani, Christina A; O'Reilly, Richard; Singh, Shiva M

    2011-03-02

    Genetic individuality is the foundation of personalized medicine, yet its determinants are currently poorly understood. One issue is the difference between monozygotic twins that are assumed identical and have been extensively used in genetic studies for decades. Here, we report genome-wide alterations in two nuclear families each with a pair of monozygotic twins discordant for schizophrenia evaluated by the Affymetrix 6.0 human SNP array. The data analysis includes characterization of copy number variations (CNVs) and single nucleotide polymorphism (SNPs). The results have identified genomic differences between twin pairs and a set of new provisional schizophrenia genes. Samples were found to have between 35 and 65 CNVs per individual. The majority of CNVs (~80%) represented gains. In addition, ~10% of the CNVs were de novo (not present in parents), of these, 30% arose during parental meiosis and 70% arose during developmental mitosis. We also observed SNPs in the twins that were absent from both parents. These constituted 0.12% of all SNPs seen in the twins. In 65% of cases these SNPs arose during meiosis compared to 35% during mitosis. The developmental mitotic origin of most CNVs that may lead to MZ twin discordance may also cause tissue differences within individuals during a single pregnancy and generate a high frequency of mosaics in the population. The results argue for enduring genome-wide changes during cellular transmission, often ignored in most genetic analyses.

  17. 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.

  18. 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.

  19. 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.

  20. Social Individualism.

    ERIC Educational Resources Information Center

    Cornille, Thomas A.; Harrigan, John

    Relationships between individuals and society have often been presented from the perspective of the social institution. Social psychology has addressed the variables that affect the individual in relationships with larger groups. Social individualism is a conceptual framework that explores the relationship of the individual and society from the…

  1. Extragalactic Backgrounds after Planck

    NASA Astrophysics Data System (ADS)

    Dore, Olivier

    Among the potentially most important results of cosmology in the last decade is the realization that the star formation rate at redshifts greater than 1 is higher than at present by about an order of magnitude, and that half of the energy produced since the surface of last scattering has been absorbed and reemitted by dust. Most of the light produced by stars at high redshifts thus reaches us in the far infrared. This radiation is referred to as the cosmic infrared background (CIB) and is emitted primarily by dusty, star-forming galaxies at redshift z=1-4. Embedded in far infrared emission of the CIB is the history of star formation, dust production, and the growth of large scale structures. Our research project aims at shedding new light on several extragalactic backgrounds investigated by NASA surveys, in light of recent observational progresses in mapping the CIB. Most lately, two new missions, Planck and Herschel, released ground-breaking measurements of the CIB. These measurements are an order of magnitude deeper and wider than previous ones, and they are literally revolutionizing the field. Our understanding of these data is now advanced enough for us to leverage our measurement of the CIB in Planck and Herschel, in order to extract new scientific insights from past missions. We propose to combine Planck and Herschel public data with archival data from WISE, GALEX, Chandra and Fermi. Not only original, the impact of our research project should be immediate. Using the CIB as a full sky, bright, high redshift reference extragalactic background, we will exploit the underlying physical connection among these various cosmological datasets. We expect new insights about the CIB, but also about the multiple extragalactic backgrounds probed in combination with it. In particular, we will investigate the cosmic star formation history at a period where it peaks, and because the clustering of matter is driven by dark matter, the measurement of the CIB clustering also

  2. 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.

  3. [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.

  4. Sources of excessive saturated fat, trans fat and sugar consumption in Brazil: an analysis of the first Brazilian nationwide individual dietary survey

    PubMed Central

    Pereira, Rosangela A; Duffey, Kiyah J; Sichieri, Rosely; Popkin, Barry M

    2013-01-01

    Objective To examine the patterns of consumption of foods high in Solid Fats and Added Sugars (SoFAS) in Brazil. Design Cross-sectional study; individual dietary intake survey. Food intake was assessed by means of two non-consecutive food records. Foods providing >9.1% of energy from SAFA, or >1.3% of energy from TFA, or >13% of energy from added sugars per 100g were classified as high in SoFAS. Setting Brazilian nationwide survey, 2008-09. Subjects ≥10 years old individuals. Results Mean energy intake was 8,037 kJ [1,921kcal], 52% of calories came from SoFAS foods. Contribution of SoFAS foods to total energy intake was higher among women (52%) and adolescents (54%). Subjects in rural areas (43%) and in the lowest quartile of per capita family income (43%) reported the smallest contribution of SoFAS foods to total energy intake. SoFAS foods were large contributors to total SAFA (87%), TFA (89%), added sugar (98%), and total sugar (96%) consumption. The SoFAS food groups that contributed most to total energy intake were the meats and beverages. Top SoFAS foods contributing to SAFA and TFA intakes were meats and fats and oils. Most of the added and total sugar in the diet was supplied by SoFAS beverages and sweets and desserts. Conclusions SoFAS foods play an important role in the Brazilian diet. This study identifies options for improving the Brazilian diet and reducing nutrition-related non communicable chronic diseases, but also points out some limitations of the nutrient-based criteria. PMID:23190560

  5. Sources of excessive saturated fat, trans fat and sugar consumption in Brazil: an analysis of the first Brazilian nationwide individual dietary survey.

    PubMed

    Pereira, Rosangela A; Duffey, Kiyah J; Sichieri, Rosely; Popkin, Barry M

    2014-01-01

    To examine the patterns of consumption of foods high in solid fats and added sugars (SoFAS) in Brazil. Cross-sectional study; individual dietary intake survey. Food intake was assessed by means of two non-consecutive food records. Foods providing >9·1% of energy from saturated fat, or >1·3% of energy from trans fat, or >13% of energy from added sugars per 100 g were classified as high in SoFAS. Brazilian nationwide survey, 2008-2009. Individuals aged ≥10 years old. Mean daily energy intake was 8037 kJ (1921 kcal), 52% of energy came from SoFAS foods. Contribution of SoFAS foods to total energy intake was higher among women (52%) and adolescents (54%). Participants in rural areas (43%) and in the lowest quartile of per capita family income (43%) reported the smallest contribution of SoFAS foods to total energy intake. SoFAS foods were large contributors to total saturated fat (87%), trans fat (89%), added sugar (98%) and total sugar (96%) consumption. The SoFAS food groups that contributed most to total energy intake were meats and beverages. Top SoFAS foods contributing to saturated fat and trans fat intakes were meats and fats and oils. Most of the added and total sugar in the diet was supplied by SoFAS beverages and sweets and desserts. SoFAS foods play an important role in the Brazilian diet. The study identifies options for improving the Brazilian diet and reducing nutrition-related non-communicable chronic diseases, but also points out some limitations of the nutrient-based criteria.

  6. Retrospective source attribution for source-oriented sampling

    NASA Astrophysics Data System (ADS)

    Bein, K. J.; Zhao, Y.; Wexler, A. S.

    2015-10-01

    Previous work successfully implemented a novel system that uses a single particle mass spectrometer to conditionally sample size-segregated, source-oriented particles from the ambient atmosphere in real-time. The underlying hypothesis is that the composition of individual particles is a metric of particle source and thus sampling particles based on composition should be synonymous with sampling based on source. System operation relies on real-time pattern recognition to control the actuation of different ChemVol samplers, where each ChemVol is associated with a unique composition signature. In the current work, a synthesis of data collected during these studies is used in retrospect to reconcile the actual source combinations contributing to the particles collected by each ChemVol. Source attribution is based on correlations between ChemVol sampling periods and coincident wind direction and temporal emissions patterns, coupled to knowledge of single particle composition and surrounding sources. Residential and commercial cooking, vehicular emissions, residential heating and highly processed regional background PM were identified as the major sources. Results show that real-time patterns in single particle mixing state correctly identified specific sources and that these sources were successfully separated into different ChemVols for both summer and winter seasons.

  7. Atmospheric mercury concentration and chemical speciation at Nam Co (4730 m a.s.l), a highland background site in the inland Tibetan Plateau: implications of mercury emission sources

    NASA Astrophysics Data System (ADS)

    Yin, X.; Kang, S.; Zhang, G.; Tong, Y.; de Foy, B.; Schauer, J. J.; Wang, X.; Zhang, W.; Zhang, Q.

    2016-12-01

    A field campaign was conducted from 1 November 2014 to 22 March 2015 at Nam Co (Tibet, China) using a set of Automatic Atmospheric Mercury Speciation Analyzers (Tekran 2537B with 1130 and 1135 units) for the measurements of gaseous elemental mercury (GEM), reactive gaseous mercury (RGM) and particulate mercury (HgP). This study is one of the first attempts to present the valuable data sets of continuous measurements of atmospheric mercury species in the inland of the TP. Average concentrations of GEM, HgP and RGM were 0.94±0.19 ng m-3, 50.61±26.74 pg m-3 and 3.15±2.79 pg m-3 (mean±SD), respectively. On an average, the atmospheric mercury apportioned as follows: GEM (94.59%)>HgP (5.09%)>RGM (0.32%). The results showed large fluctuation of GEM, RGM and HgP (GEM: 0.39-1.66 ng m-3; HgP: 4.88-157.84 pg m-3 and RGM: 0.18-29.73 pg m-3). As a whole, GEM and RGM were relatively stable during monitoring, and HgP concentrations are larger in wintertime than in later autumn and early spring. Hourly variations were observed for the mercury species. Maximum GEM concentrations was measured normally after sunrise whereas HgP reached its maximum before sunrise and RGM was maximum in the afternoon. The backward trajectory model showed that atmospheric mercury sources from South Asia and local sources contributed to the Nam Co atmospheric mercury contamination.

  8. X-ray microprobe studies of Hungarian background and urban aerosols

    SciTech Connect

    Toeroek, S.; Sandor, S. . Central Research Inst. for Physics); Xhoffer, C.; Van Grieken, R. . Dept. of Chemistry); Jones, K.W. ); Sutton, S.R.; Rivers, M.L. )

    1991-10-01

    In order to determine the polluting atmospheric sources in urban and background areas source apportionment of the air particulate matter is necessary. Hitherto these studies were mostly based on bulk composition measurements of the aerosol. Source profiles, i.e. the concentrations of several elements for air particulate matter originating from one source, can be deduced from the receptor data using a number of multivariate techniques among which the chemical mass balance. The application is limited by the large number of observations that must be made for each of the variables. Often an elaborated sample preparation is necessary for fractionating the sample into several sub samples, according to the density, particle diameter or other relevant properties. Often this may results in poorly resolved source profiles. The aim of the present work is to find the relative abundance of the particle types originating from two different background monitoring stations in the middle of the Great Hungarian Plain. In urban areas most pollutants originate from traffic and municipal waste incineration. Since heavy metals play an important role in these samples the highly sensitive x-ray microscope (XRM) of the National Synchrotron Light Source (NSLS) of the Brookhaven National Laboratory was used. A feasibility study on individual aerosol particles sampled at the above background stations and in the urban area of Budapest is discussed.

  9. 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

  10. Tracking the provenance of Greenland-sourced, Holocene aged, individual sand-sized ice-rafted debris using the Pb-isotope compositions of feldspars and 40Ar/39Ar ages of hornblendes

    NASA Astrophysics Data System (ADS)

    White, Lee F.; Bailey, Ian; Foster, Gavin L.; Allen, Georgina; Kelley, Simon P.; Andrews, John T.; Hogan, Kelly; Dowdeswell, Julian A.; Storey, Craig D.

    2016-01-01

    The provenance of sand-sized ice-rafted debris (IRD) sourced from Greenland is currently difficult to determine. Such knowledge, if it could be ascertained with a high degree of certainty, could be applied to the Greenland-proximal marine records to improve both our understanding of modern-day spatial patterns of iceberg rafting and the past history of the Greenland Ice Sheet (GIS). Recent studies have highlighted the utility of the Pb-isotope composition of individual sand-sized feldspars and the 40Ar/39Ar ages of individual sand-sized hornblendes in this regard. However, before any such provenance toolkit can be applied to the palaeo-record, it is necessary first to determine whether this approach can be used to track the sources of known recent Greenland-proximal IRD deposition. To this end we present new records of the Pb-isotope composition and the 40Ar/39Ar ages of individual sand-sized grains of feldspars and hornblendes, respectively, from modern Greenland glacifluvial and fjord sands and Holocene to modern Greenland-proximal marine sediments. These new data demonstrate that sand-sized feldspars and hornblendes glacially eroded by the GIS exhibit distinct intra- and inter-tectonic terrane differences in their Pb-isotope compositions and ages and that these differences are clearly expressed in the geochemistry and geochronology of sand-sized IRD deposited in marine sediments around Greenland. Although overlap exists between some Greenland-proximal IRD 'source fields' defined by these data, our approach has the potential to both better understand spatial patterns of Greenland-derived IRD in the modern day as well as during past episodes of iceberg calving.

  11. Background Radioactivity in River and Reservoir Sediments near Los Alamos, New Mexico

    SciTech Connect

    S.G.McLin; D.W. Lyons

    2002-05-05

    As part of its continuing Environmental Surveillance Program, regional river and lake-bottom sediments have been collected annually by Los Alamos National Laboratory (the Laboratory) since 1974 and 1979, respectively. These background samples are collected from three drainage basins at ten different river stations and five reservoirs located throughout northern New Mexico and southern Colorado. Radiochemical analyses for these sediments include tritium, strontium-90, cesium-137, total uranium, plutonium-238, plutonium-239,-240, americium-241, gross alpha, gross beta, and gross gamma radioactivity. Detection-limit radioactivity originates as worldwide fallout from aboveground nuclear weapons testing and satellite reentry into Earth's atmosphere. Spatial and temporal variations in individual analyte levels originate from atmospheric point-source introductions and natural rate differences in airborne deposition and soil erosion. Background radioactivity values on sediments reflect this variability, and grouped river and reservoir sediment samples show a range of statistical distributions that appear to be analyte dependent. Traditionally, both river and reservoir analyte data were blended together to establish background levels. In this report, however, we group background sediment data according to two criteria. These include sediment source (either river or reservoir sediments) and station location relative to the Laboratory (either upstream or downstream). These grouped data are statistically evaluated through 1997, and background radioactivity values are established for individual analytes in upstream river and reservoir sediments. This information may be used to establish the existence and areal extent of trace-level environmental contamination resulting from historical Laboratory research activities since the early 1940s.

  12. 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

  13. The Quest for the astrophysical background with Advanced LIGO/Virgo

    NASA Astrophysics Data System (ADS)

    Regimbau, Tania; LIGO Virgo Collaboration Collaboration

    2016-03-01

    In addition to the cosmological background, an astrophysical background may have resulted from the superposition of a large number of unresolved sources since the beginning of stellar activity. This astrophysical contribution could be a foreground masking the cosmological background but it can also provide very interesting informations, not only about the physical properties of the respective astrophysical populations, complementing individual GW detections, but also about the evolution of these objects with redshift, the star formation history or the metallicity. In this talk, predictions of the gravitational wave background formed by all the compact binary coalescences at cosmological distances will be given, as well as a discussion of their accessibility with the network of Advanced LIGO/Virgo detectors. Finally, the expected astrophysical and cosmological constraints to be made by Advanced LIGO/Virgo will be presented.

  14. Biological Individuality of Man

    DTIC Science & Technology

    1974-12-01

    RECIPIENT’S CAT * LOO NUMBER Biological Individuality of Man 5 TlrPE OF REPORT a PERIOD COVERED Technical « PERFORMING ORO REPORT...Variability 13 A. Background , 13 B. Slatistictl Approaches to Biological Variability 13 C. Genetic Aspects of Biological Variability . 14 III...ioiological determinants of individuality. Only recently, have genetic infaienccs been investigated and the potentialities for future control of bio

  15. 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.

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. Source Water Quality Monitoring

    EPA Science Inventory

    Presentation will provide background information on continuous source water monitoring using online toxicity monitors and cover various tools available. Conceptual and practical aspects of source water quality monitoring will be discussed.

  3. European Spallation Source

    NASA Astrophysics Data System (ADS)

    Eshraqi, Mohammad; McGinnis, David; Lindroos, Mats

    The following sections are included: * Neutron usage and historical background * Spallation * History of spallation sources * The ESS facility * The ESS linac * Beam physics * The front-end and the normal conducting linac * Superconducting linac * RF sources * Summary * References

  4. Source Water Quality Monitoring

    EPA Science Inventory

    Presentation will provide background information on continuous source water monitoring using online toxicity monitors and cover various tools available. Conceptual and practical aspects of source water quality monitoring will be discussed.

  5. Intake estimation of total and individual flavan-3-ols, proanthocyanidins and theaflavins, their food sources and determinants in the European Prospective Investigation into Cancer and Nutrition (EPIC) study.

    PubMed

    Knaze, Viktoria; Zamora-Ros, Raul; Luján-Barroso, Leila; Romieu, Isabelle; Scalbert, Augustin; Slimani, Nadia; Riboli, Elio; van Rossum, Caroline T M; Bueno-de-Mesquita, H Bas; Trichopoulou, Antonia; Dilis, Vardis; Tsiotas, Konstantinos; Skeie, Guri; Engeset, Dagrun; Quirós, J Ramón; Molina, Esther; Huerta, José María; Crowe, Francesca; Wirfäl, Elisabet; Ericson, Ulrika; Peeters, Petra H M; Kaaks, Rudolf; Teucher, Birgit; Johansson, Gerd; Johansson, Ingegerd; Tumino, Rosario; Boeing, Heiner; Drogan, Dagmar; Amiano, Pilar; Mattiello, Amalia; Khaw, Kay-Tee; Luben, Robert; Krogh, Vittorio; Ardanáz, Eva; Sacerdote, Carlotta; Salvini, Simonetta; Overvad, Kim; Tjønneland, Anne; Olsen, Anja; Boutron-Ruault, Marie-Christine; Fagherazzi, Guy; Perquier, Florence; González, Carlos A

    2012-09-28

    Epidemiological studies suggest health-protective effects of flavan-3-ols and their derived compounds on chronic diseases. The present study aimed to estimate dietary flavan-3-ol, proanthocyanidin (PA) and theaflavin intakes, their food sources and potential determinants in the European Prospective Investigation into Cancer and Nutrition (EPIC) calibration cohort. Dietary data were collected using a standardised 24 h dietary recall software administered to 36 037 subjects aged 35-74 years. Dietary data were linked with a flavanoid food composition database compiled from the latest US Department of Agriculture and Phenol-Explorer databases and expanded to include recipes, estimations and retention factors. Total flavan-3-ol intake was the highest in UK Health-conscious men (453·6 mg/d) and women of UK General population (377·6 mg/d), while the intake was the lowest in Greece (men: 160·5 mg/d; women: 124·8 mg/d). Monomer intake was the highest in UK General population (men: 213·5 mg/d; women: 178·6 mg/d) and the lowest in Greece (men: 26·6 mg/d in men; women: 20·7 mg/d). Theaflavin intake was the highest in UK General population (men: 29·3 mg/d; women: 25·3 mg/d) and close to zero in Greece and Spain. PA intake was the highest in Asturias (men: 455·2 mg/d) and San Sebastian (women: 253 mg/d), while being the lowest in Greece (men: 134·6 mg/d; women: 101·0 mg/d). Except for the UK, non-citrus fruits (apples/pears) were the highest contributors to the total flavan-3-ol intake. Tea was the main contributor of total flavan-3-ols in the UK. Flavan-3-ol, PA and theaflavin intakes were significantly different among all assessed groups. This study showed heterogeneity in flavan-3-ol, PA and theaflavin intake throughout the EPIC countries.

  6. 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.

  7. Summary of the Workshop on Ultraviolet Cosmic Background Radiation

    NASA Technical Reports Server (NTRS)

    Henry, R. C.

    1981-01-01

    The relationship of the ultraviolet background radiation to the X-ray background is shown. The ultraviolet background, which is four orders of magnitude brighter than the x-ray background, is much less well determined. The relationship of the ultraviolet background to the EUV background and an excellent summary of the discordant ultraviolet observations at high galactic latitudes are given. A picture of the universe from the point of view of those who study ultraviolet background radiation, with emphasis on the various sources of noise that can affect the measurements is presented. The altitudes of various observing platforms are also indicated.

  8. Slurry sampling high-resolution continuum source electrothermal atomic absorption spectrometry for direct beryllium determination in soil and sediment samples after elimination of SiO interference by least-squares background correction.

    PubMed

    Husáková, Lenka; Urbanová, Iva; Šafránková, Michaela; Šídová, Tereza

    2017-12-01

    In this work a simple, efficient, and environmentally-friendly method is proposed for determination of Be in soil and sediment samples employing slurry sampling and high-resolution continuum source electrothermal atomic absorption spectrometry (HR-CS-ETAAS). The spectral effects originating from SiO species were identified and successfully corrected by means of a mathematical correction algorithm. Fractional factorial design has been employed to assess the parameters affecting the analytical results and especially to help in the development of the slurry preparation and optimization of measuring conditions. The effects of seven analytical variables including particle size, concentration of glycerol and HNO3 for stabilization and analyte extraction, respectively, the effect of ultrasonic agitation for slurry homogenization, concentration of chemical modifier, pyrolysis and atomization temperature were investigated by a 2(7-3) replicate (n = 3) design. Using the optimized experimental conditions, the proposed method allowed the determination of Be with a detection limit being 0.016mgkg(-1) and characteristic mass 1.3pg. Optimum results were obtained after preparing the slurries by weighing 100mg of a sample with particle size < 54µm and adding 25mL of 20% w/w glycerol. The use of 1μg Rh and 50μg citric acid was found satisfactory for the analyte stabilization. Accurate data were obtained with the use of matrix-free calibration. The accuracy of the method was confirmed by analysis of two certified reference materials (NIST SRM 2702 Inorganics in Marine Sediment and IGI BIL-1 Baikal Bottom Silt) and by comparison of the results obtained for ten real samples by slurry sampling with those determined after microwave-assisted extraction by inductively coupled plasma time of flight mass spectrometry (TOF-ICP-MS). The reported method has a precision better than 7%. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. 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

  10. Background Information Framework for the National Assessment of Educational Progress.

    ERIC Educational Resources Information Center

    National Assessment Governing Board, Washington, DC.

    This framework will define the purpose and scope of NAEP's system of collecting background information, including background questionnaires and other sources of non-cognitive data. It will establish criteria for reporting background information as part of the National Assessment. The approach it suggests provides for asking various groups of…

  11. Applied Music (Individual Study).

    ERIC Educational Resources Information Center

    Texas Education Agency, Austin.

    Background information and resources to help students in grades 9-12 in Texas pursue an individual study contract in applied music is presented. To fulfill a contract students must publicly perform from memory, with accompaniment as specified, three selections from a list of approved music for their chosen field (instrument or voice). Material…

  12. Applied Music (Individual Study).

    ERIC Educational Resources Information Center

    Texas Education Agency, Austin.

    Background information and resources to help students in grades 9-12 in Texas pursue an individual study contract in applied music is presented. To fulfill a contract students must publicly perform from memory, with accompaniment as specified, three selections from a list of approved music for their chosen field (instrument or voice). Material…

  13. Reduction of background clutter in structured lighting systems

    DOEpatents

    Carlson, Jeffrey J.; Giles, Michael K.; Padilla, Denise D.; Davidson, Jr., Patrick A.; Novick, David K.; Wilson, Christopher W.

    2010-06-22

    Methods for segmenting the reflected light of an illumination source having a characteristic wavelength from background illumination (i.e. clutter) in structured lighting systems can comprise pulsing the light source used to illuminate a scene, pulsing the light source synchronously with the opening of a shutter in an imaging device, estimating the contribution of background clutter by interpolation of images of the scene collected at multiple spectral bands not including the characteristic wavelength and subtracting the estimated background contribution from an image of the scene comprising the wavelength of the light source and, placing a polarizing filter between the imaging device and the scene, where the illumination source can be polarized in the same orientation as the polarizing filter. Apparatus for segmenting the light of an illumination source from background illumination can comprise an illuminator, an image receiver for receiving images of multiple spectral bands, a processor for calculations and interpolations, and a polarizing filter.

  14. 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.

  15. 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.

  16. Individual Education.

    ERIC Educational Resources Information Center

    Corsini, Raymond

    1981-01-01

    Paper presented at the 66th Convention of the International Association of Pupil Personnel Workers, October 20, 1980, Baltimore, Maryland, describes individual education based on the principles of Alfred Adler. Defines six advantages of individual education, emphasizing student responsibility, mutual respect, and allowing students to progress at…

  17. Individual Education.

    ERIC Educational Resources Information Center

    Corsini, Raymond

    1981-01-01

    Paper presented at the 66th Convention of the International Association of Pupil Personnel Workers, October 20, 1980, Baltimore, Maryland, describes individual education based on the principles of Alfred Adler. Defines six advantages of individual education, emphasizing student responsibility, mutual respect, and allowing students to progress at…

  18. 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.

  19. Source of Individual Differences in Digit Span

    DTIC Science & Technology

    1975-09-01

    University of Oregon Eugene , Oiigon 97403 " CONTROLLING orriCC N AMI AND ADONKM Personnel and Training Research Programs Office of Naval...the Graduate School, University of Oregon Eugene , Oregon tS. RIV WORDS ’ConKnu» on r»y»’t* iltt :I ntcftf ■»<< UtnAty .y Sleek numbt...0004 1 April 1974 - 30 Sept. 1975 Principal Investigator: Steven W. Keele Department of Psychology University of Oregon Eugene , Oregon (503

  20. Optical and infrared backgrounds from the Hubble Space Telescope

    NASA Astrophysics Data System (ADS)

    Dolch, Timothy

    The sum total of the energy released by the earliest era of star formation should show up today within the diffuse extragalactic background light (EBL), its signature peaking in the near-infrared. There is considerable controversy over estimates of the average EBL per steradian at optical and infrared wavelengths, over measurements of background fluctuations, and over the interpretation of the measurements. Resolving this controversy is important because the EBL constrains the history of galaxy evolution. The fluctuations and their colors may also contain important information about Population III stars and the earliest era of star formation. We compare number counts from recent galaxy surveys, correcting for their differing passbands. With some assumptions about galaxy sizes and surface-brightness profiles, we account for the light missed in standard photometric estimates, integrating the resulting corrected counts to estimate the total EBL due to resolved galaxies as well as undetected galaxies. We then present an analysis of background fluctuations in observations of the HUDF, the GOODS field, and the CANDELS fields obtained with WFC3. The fluctuation signal provides a constraint on the slope of galaxy counts fainter than the levels of individual detection, as well as their typical angular sizes. The color dependence of the fluctuations provides a constraint on the redshift distribution of these very faint sources. The spatial and spectral information from these anisotropies, even in their non-detection, provide valuable information about the era of reionization, when the first stars and galaxies formed. Via various analysis tools such as power spectra and P(D) fitting, best-fit models to faint sources can be obtained.

  1. 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.

  2. 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

  3. Apparatus for reducing solvent luminescence background emissions

    DOEpatents

    Affleck, Rhett L.; Ambrose, W. Patrick; Demas, James N.; Goodwin, Peter M.; Johnson, Mitchell E.; Keller, Richard A.; Petty, Jeffrey T.; Schecker, Jay A.; Wu, Ming

    1998-01-01

    The detectability of luminescent molecules in solution is enhanced by reducing the background luminescence due to impurity species also present in the solution. A light source that illuminates the solution acts to photolyze the impurities so that the impurities do not luminesce in the fluorescence band of the molecule of interest. Molecules of interest may be carried through the photolysis region in the solution or may be introduced into the solution after the photolysis region.

  4. Apparatus for reducing solvent luminescence background emissions

    DOEpatents

    Affleck, R.L.; Ambrose, W.P.; Demas, J.N.; Goodwin, P.M.; Johnson, M.E.; Keller, R.A.; Petty, J.T.; Schecker, J.A.; Wu, M.

    1998-11-10

    The detectability of luminescent molecules in solution is enhanced by reducing the background luminescence due to impurity species also present in the solution. A light source that illuminates the solution acts to photolyze the impurities so that the impurities do not luminesce in the fluorescence band of the molecule of interest. Molecules of interest may be carried through the photolysis region in the solution or may be introduced into the solution after the photolysis region. 6 figs.

  5. 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.

  6. Individual Instruction: A Bibliography.

    ERIC Educational Resources Information Center

    Dirr, Peter J.

    The bibliography lists 58 references (1969-74) on individualized instruction. Topics covered include computer assisted instruction, diagnostic teaching, and instructional materials, for handicapped as well as nonhandicapped children. Entries are listed in alphabetical order by author (or source) and usually include name of publisher, date, and…

  7. Soudan Low Background Counting Facility (SOLO)

    SciTech Connect

    Attisha, Michael; Viveiros, Luiz de; Gaitksell, Richard; Thompson, John-Paul

    2005-09-08

    The Soudan Low Background Counting Facility (SOLO) has been in operation at the Soudan Mine, MN since March 2003. In the past two years, we have gamma-screened samples for the Majorana, CDMS and XENON experiments. With individual sample exposure times of up to two weeks we have measured sample contamination down to the 0.1 ppb level for 238U / 232Th, and down to the 0.25 ppm level for 40K.

  8. Signal and background in the underwater neutrino telescope ANTARES

    NASA Astrophysics Data System (ADS)

    de Vries-Uiterweerd, G.

    2007-05-01

    bioluminescent activity. The main method of detecting cosmic neutrino sources is to reconstruct muon tracks caused by neutrino interactions. At low energies, this method is inefficient, because not enough light is produced. A new method has been devised to search for a low-energy neutrino flux from a given direction, without reconstructing individual muon tracks. This velocity filter is based on the asymmetry in the patterns of photon arrival times caused by a muon. The velocity filter was tested on simulated data, assuming a neutrino flux as is expected from Supernova Remnant RX J1713.7-3946 (~ 10-4 (E/GeV)-2.2 m-2 s-1 GeV-1). The neutrino signal cannot be detected, partly due to the large systematic uncertainty on the flux of atmospheric muons, but mainly because the expected neutrino flux is too low to be detectable above the statistical error on the background. A neutrino flux about three orders of magnitude larger than the flux expected from RX J1713.7-3946 can be detected at the 5σ level. In larger detectors and with less optical background, the velocity filter may be able to detect cosmic neutrino sources.

  9. 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.

  10. 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.

  11. Visual signal detection in structured backgrounds. II. Effects of contrast gain control, background variations, and white noise

    NASA Technical Reports Server (NTRS)

    Eckstein, M. P.; Ahumada, A. J. Jr; Watson, A. B.

    1997-01-01

    Studies of visual detection of a signal superimposed on one of two identical backgrounds show performance degradation when the background has high contrast and is similar in spatial frequency and/or orientation to the signal. To account for this finding, models include a contrast gain control mechanism that pools activity across spatial frequency, orientation and space to inhibit (divisively) the response of the receptor sensitive to the signal. In tasks in which the observer has to detect a known signal added to one of M different backgrounds grounds due to added visual noise, the main sources of degradation are the stochastic noise in the image and the suboptimal visual processing. We investigate how these two sources of degradation (contrast gain control and variations in the background) interact in a task in which the signal is embedded in one of M locations in a complex spatially varying background (structured background). We use backgrounds extracted from patient digital medical images. To isolate effects of the fixed deterministic background (the contrast gain control) from the effects of the background variations, we conduct detection experiments with three different background conditions: (1) uniform background, (2) a repeated sample of structured background, and (3) different samples of structured background. Results show that human visual detection degrades from the uniform background condition to the repeated background condition and degrades even further in the different backgrounds condition. These results suggest that both the contrast gain control mechanism and the background random variations degrade human performance in detection of a signal in a complex, spatially varying background. A filter model and added white noise are used to generate estimates of sampling efficiencies, an equivalent internal noise, an equivalent contrast-gain-control-induced noise, and an equivalent noise due to the variations in the structured background.

  12. Visual signal detection in structured backgrounds. II. Effects of contrast gain control, background variations, and white noise

    NASA Technical Reports Server (NTRS)

    Eckstein, M. P.; Ahumada, A. J. Jr; Watson, A. B.

    1997-01-01

    Studies of visual detection of a signal superimposed on one of two identical backgrounds show performance degradation when the background has high contrast and is similar in spatial frequency and/or orientation to the signal. To account for this finding, models include a contrast gain control mechanism that pools activity across spatial frequency, orientation and space to inhibit (divisively) the response of the receptor sensitive to the signal. In tasks in which the observer has to detect a known signal added to one of M different backgrounds grounds due to added visual noise, the main sources of degradation are the stochastic noise in the image and the suboptimal visual processing. We investigate how these two sources of degradation (contrast gain control and variations in the background) interact in a task in which the signal is embedded in one of M locations in a complex spatially varying background (structured background). We use backgrounds extracted from patient digital medical images. To isolate effects of the fixed deterministic background (the contrast gain control) from the effects of the background variations, we conduct detection experiments with three different background conditions: (1) uniform background, (2) a repeated sample of structured background, and (3) different samples of structured background. Results show that human visual detection degrades from the uniform background condition to the repeated background condition and degrades even further in the different backgrounds condition. These results suggest that both the contrast gain control mechanism and the background random variations degrade human performance in detection of a signal in a complex, spatially varying background. A filter model and added white noise are used to generate estimates of sampling efficiencies, an equivalent internal noise, an equivalent contrast-gain-control-induced noise, and an equivalent noise due to the variations in the structured background.

  13. 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.

  14. Students' Daily Emotions in the Classroom: Intra-Individual Variability and Appraisal Correlates

    ERIC Educational Resources Information Center

    Ahmed, Wondimu; van der Werf, Greetje; Minnaert, Alexander; Kuyper, Hans

    2010-01-01

    Background: Recent literature on emotions in education has shown that competence- and value-related beliefs are important sources of students' emotions; nevertheless, the role of these antecedents in students' daily functioning in the classroom is not yet well-known. More importantly, to date we know little about intra-individual variability in…

  15. Using Administrative Health Data to Identify Individuals with Intellectual and Developmental Disabilities: A Comparison of Algorithms

    ERIC Educational Resources Information Center

    Lin, E.; Balogh, R.; Cobigo, V.; Ouellette-Kuntz, H.; Wilton, A. S.; Lunsky, Y.

    2013-01-01

    Background: Individuals with intellectual and developmental disabilities (IDD) experience high rates of physical and mental health problems; yet their health care is often inadequate. Information about their characteristics and health services needs is critical for planning efficient and equitable services. A logical source of such information is…

  16. Using Administrative Health Data to Identify Individuals with Intellectual and Developmental Disabilities: A Comparison of Algorithms

    ERIC Educational Resources Information Center

    Lin, E.; Balogh, R.; Cobigo, V.; Ouellette-Kuntz, H.; Wilton, A. S.; Lunsky, Y.

    2013-01-01

    Background: Individuals with intellectual and developmental disabilities (IDD) experience high rates of physical and mental health problems; yet their health care is often inadequate. Information about their characteristics and health services needs is critical for planning efficient and equitable services. A logical source of such information is…

  17. Individualizing Medicare.

    PubMed

    Chollet, D J

    1999-05-01

    Despite the enactment of significant changes to the Medicare program in 1997, Medicare's Hospital Insurance trust fund is projected to be exhausted just as the baby boom enters retirement. To address Medicare's financial difficulties, a number of reform proposals have been offered, including several to individualize Medicare financing and benefits. These proposals would attempt to increase Medicare revenues and reduce Medicare expenditures by having individuals bear risk--investment market risk before retirement and insurance market risk after retirement. Many fundamental aspects of these proposals have yet to be worked out, including how to guarantee a baseline level of saving for health insurance after retirement, how retirees might finance unanticipated health insurance price increases after retirement, the potential implications for Medicaid of inadequate individual saving, and whether the administrative cost of making the system fair and adequate ultimately would eliminate any rate-of-return advantages from allowing workers to invest their Medicare contributions in corporate stocks and bonds.

  18. Z > 6 Galaxy Signatures in the Infrared Background and the 21-cm background

    NASA Astrophysics Data System (ADS)

    Cooray, A.

    2006-08-01

    We will discuss the signatures of the high-redshift galaxy formation in the near-infrared background. Ionizing sources at high redshift generically imprint a distinctive Lyman-cutoff feature and a unique spatial anisotropy signature to the IRB, both of which may be detectable in a short rocket flight. We will discuss the Cosmic Infrared Background ExpeRiment (CIBER), a rocket-borne instrument to probe the absolute spectrum and spatial anisotropy of the extragalactic InfraRed Background (IRB) optimized for detection of the integrated spatial anisotropies in the IR background from high-redshift galaxies. We will also discuss the signatures of first galaxies in the low radio frequency 21-cm background from the neutral Hydrogen distribution at z > 6; When combined with arcminute-scale temperature anisotropy and the polarization of the cosmic microwave background, the 21-cm background will allow a determination of inhomogeneous distribution of Lyman-alpha photons from first galaxies. We will discuss these and other possibilities to understand the first galaxy population with IR, 21-cm, and CMB backgrounds.

  19. 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.

  20. 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 decou