WorldWideScience

Sample records for psr pacific-sierra research

  1. Nuclear Weapon Effect Research at PSR (Pacific-Sierra Research Corporation) - 1983. Acute Radiation Effects on Individual Crewmember Performance

    Science.gov (United States)

    1984-08-31

    a-l I 1- lI s~1ý u. -. IW xal .. 0 . N cr 2CL4.u I7 V~f 7uX r, I. a. L 7~ - - - - - - - - - - - ~~202 .I a I z N~ ~~~~ W S 0.I &I I , 4 Z ,a I m - a...ATZN-MP-Library ATTN: Commander 2 cys ATIN: ATZN-MP- TD 2 cys ATTN: Commandant Carrier Group 7 2 cys ATTN: Fhys Scty Committee ATTN: Commander US Army

  2. Nuclear Weapon Effect Research at PSR (Pacific-Sierra Research Corporation) - 1983. Symptomatology of Acute Radiation Effects in Humans after Exposure to Doses of 75 to 4500 Rads (cGy) Free-in-Air

    Science.gov (United States)

    1984-08-31

    Lhe end of the first postexposure week, infection is rampant from endogenous bacteria that have escaped from the injured gastrointestinal tract. The...Pancytopenia supervenes about 3 to 4 weeks later; it becomes complete at doses above 750 rads (cGy).t Purpura is evident, and bleeding may be uncontrolled...of the manifest-illness piiase. Under normal conditions, the integrity of the intestinal mucosa prevents the substantial escape of bacteria into the

  3. Research on the maximum utilization of PSR (Periodic Safety Review) results

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Tae Myung; Lee, Jae Kyung; Ahn, Jin Chul; Kim, G. U.; Ryu, Y. S.; Lee, G. B.; Park, D. H. [Chungju Univ., Cheongju (Korea, Republic of)

    2002-03-15

    This is the final report of 'research on the maximum utilization of PSR results' focused on linkage strategy of PSR with continued operation over design life of operating NPP. Study was mace mainly on the analysis of current status of continued operation over plant design life in foreign countries, analysis of domestic PSR implementation status and establishment of basic strategy for linking PSR with continued operation. The results of the study performed so far can be summarized as below, the recent worldwide trend of promoting efficiency of NPP operation is focused on life extension of the plants rather than building of new. Considering the fact that some developed countries have already implemented the plant life extension and not a few countries at least have invested a good amount of fund for R and D of plant life management, we can not disregard the owner's request for review of life extension application without any reasonable description. As a result of investigation and analysis for the current status of continued operation over plant design life in foreign countries, it is concluded that most countries tend to link PSR with continued operation over plant design life and the extended operation has already been implemented in some developed countries. From the point, it turned out to be more desirable to couple those two systems for continued operation over plant design life of Korean NPP. A less than 7 years left until the end of design life for the oldest NPP Kori unit 1, it is strongly recommended to establish institutional frame including a legal basis and regulatory guidelines for continued operation over plant design life before long. For the prioritization methods of corrective actions in consideration of safety significance of shortcomings picked up from PSR, some related systems are reviewed including IAEA guidelines, PSR implementation experience of UK and US prioritization system for GSI (Generic Safety Issue). Basic principles are

  4. SMEX03 Aircraft Polarimetric Scanning Radiometer (PSR) Data

    Data.gov (United States)

    National Aeronautics and Space Administration — The Polarimetric Scanning Radiometer (PSR) is an airborne microwave imaging radiometer developed and operated by the National Oceanic and Atmospheric Administration...

  5. SMEX02 Aircraft Polarimetric Scanning Radiometer (PSR) Data

    Data.gov (United States)

    National Aeronautics and Space Administration — The Polarimetric Scanning Radiometer (PSR) is an airborne microwave imaging radiometer developed and operated by the National Oceanic and Atmospheric Administration...

  6. Detection of pulsars PSR 1133 + 16 and PSR 2045-16 at low radio frequencies

    Science.gov (United States)

    Reyes, F.; Carr, T. D.; Oliver, J. P.; May, J.; Bitran, M.; Aparici, J.

    1981-12-01

    Two pulsars have been observed at low radio frequencies using a narrow bandwidth to avoid pulse dispersion problems, PSR 1133 + 16 was observed at 26.3 MHz using the University of Florida 640-dipole radiotelescope. PSR 2045-16 was observed at 45 MHz using the MaipuRadio Astronomy Observatory 528-dipole radiotelescope. Digital averaging and period-stacking techniques were used in order to increase the signal-to-noise ratio. Both pulsars were successfully detected by averaging typically 400 to 600 periods. The integrated pulse profile, pulse width and an estimate of the pulse flux density and energy were obtained. The systematic observation of pulsars using both radiotelescopes will be soon started.

  7. Similarity of PSR J1906+0746 TO PSR J0737-3039: A Candidate of a New Double Pulsar System?

    Science.gov (United States)

    Yang, Yi-Yan; Zhang, Cheng-Min; Li, Di; Wang, De-Hua; Pan, Yuan-Yue; Lingfu, Rong-Feng; Zhou, Zhu-Wen

    2017-02-01

    PSR J1906+0746 is a nonrecycled strong magnetic field neutron star (NS), sharing the properties of the secondary-formed NS PSR J0737-3039B in the double pulsar system PSR J0737-3039AB. By comparing the orbital parameters of PSR J1906+0746 with those of PSR J0737-3039AB, we conclude that both systems have a similar origin and evolution history, involving an e-capture process for forming the second-born NS, like in the case of PSR J0737-3039B. We expect the companion of PSR J1906+0746 to be a long-lived recycled pulsar with radio beams that currently cannot be observed from Earth. We suggest possible ways to detect its presence. To compare PSR J1906+0746 with PSR J0737-3039, we also present the mass distribution of eight pairs of double NSs and find that in double NSs the mass of the recycled pulsar is usually larger than that of the nonrecycled one, which may be the result of accretion.

  8. Gamma radiation from PSR B1055-52

    DEFF Research Database (Denmark)

    Thompson, D.J.; Bailes, M.; Bertsch, D.L.

    1999-01-01

    The telescopes on the Compton Gamma Ray Observatory (CGRO) have observed PSR B1055-52 a number of times between 1991 and 1998. From these data a more detailed picture of the gamma radiation from this source has been developed, showing several characteristics that distinguish this pulsar: the light...

  9. Optical counterparts of two Fermi millisecond pulsars: PSR J1301+0833 and PSR J1628–3205

    Energy Technology Data Exchange (ETDEWEB)

    Li, Miao; Halpern, Jules P. [Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027 (United States); Thorstensen, John R., E-mail: miao@astro.columbia.edu [Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755 (United States)

    2014-11-10

    Using the 1.3 m and 2.4 m Telescopes of the MDM Observatory, we identified the close companions of two eclipsing millisecond radio pulsars that were discovered by the Green Bank Telescope in searches of Fermi Gamma-ray Space Telescope sources, and measured their light curves. PSR J1301+0833 is a black widow pulsar in a 6.5 hr orbit whose companion star is strongly heated on the side facing the pulsar. It varies from R = 21.8 to R > 24 around the orbit. PSR J1628–3205 is a 'redback', a nearly Roche-lobe-filling system in a 5.0 hr orbit whose optical modulation in the range 19.0 < R < 19.4 is dominated by strong ellipsoidal variations, indicating a large orbital inclination angle. PSR J1628–3205 also shows evidence for a long-term variation of about 0.2 mag, and an asymmetric temperature distribution possibly due to either off-center heating by the pulsar wind, or large starspots. Modeling of its light curve restricts the inclination angle to i > 55°, the mass of the companion to 0.16 < M{sub c} < 0.30 M {sub ☉}, and the effective temperature to 3560 < T {sub eff} < 4670 K. As is the case for several redbacks, the companion of PSR J1628–3205 is less dense and hotter than a main-sequence star of the same mass.

  10. Vacuum gaps in pulsars and PSR J2144-3933

    CERN Document Server

    Gil, J; Gil, Janusz; Mitra, Dipanjan

    2001-01-01

    In this paper we revisit the radio pulsar death line problem within the framework of curvature radiation and/or inverse compton scattering induced vacuum gap model above neutron star polar caps. Our special interest is in the recently detected pulsar PSR J2144-3933 with extremal period 8.5 seconds, which lies far beyond conventional death lines. We argue, that formation of vacuum gaps requires a complicated multipolar surface magnetic field, with a strenght $B_s$ much higher than the surface dipolar component $B_d$, and radii of curvature ${\\cal R}$ much smaller than the neutron star radius $R=10^6$ cm. Such a multipolar surface field is also consistent with death lines including the extremal pulsar PSR J2144-3933. Since vacuum gap models produce sparks, our paper naturally supports the spark related models of subpulse drift phenomenon as well as to the spark associated models of coherent pulsar radio emission.

  11. The orbital light curve of PSR 1957 + 20

    Science.gov (United States)

    Callanan, Paul J.; van Paradijs, Jan; Rengelink, Roeland

    1995-02-01

    We make a detailed study of the optical light curve of PSR 1957 + 20. We show that the deep, smooth, and symmetrical modulation can be successfully modeled by a higl irradiated secondary. Two types of models are consistent with the data: (] a secondary close to filling its Rochhe lobe with 10%-20% of the incident flux converted to optical emission, and (2) a secondary considerably underfilling its Roche lobe, with a high degree of beaming of the neutron star flux. however, the second model canbe rejected on the basis of current estimates of the extinction toward 1957 + 20. The proximity of the photosphere of the secondary to its Roche lobe facilitates mass loss by irradiation. Our ignorance of the (nonirradiated) luminosity of the secondary allows us to place only weak constraints on the inclination -50-80 deg. There is no evidence in the light curve for optical emission from any source in PSR 1957 + 20 other than the secondary itself.

  12. SMEX03 Aircraft Polarimetric Scanning Radiometer (PSR) Data, Alabama, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — The Polarimetric Scanning Radiometer (PSR) is an airborne microwave imaging radiometer developed and operated by the National Oceanic and Atmospheric Administration...

  13. Current Status of Periodic Safety Review of HANARO Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Minjin; Ahn, Guk-Hoon; Lee, Choong Sung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    A PSR for a research reactor became a legal requirement as the Nuclear Safety Act was amended and came into effect in 2014. This paper describes the current status and methodology of the first Periodic Safety Review (PSR) of HANARO that is being performed. The legal requirements, work plan, and process of implementing a PSR are described. Because this is the first PSR for a research reactor, it is our understating that the operating organization and regulatory body should communicate well with each other to complete the PSR in a timely manner. The first PSR of HANARO is under way. In order to achieve a successful result, activities of the operation organization such as scheduling, maintaining consistency in input data for review, and reviewing the PSR reports that will require intensive resources should be well planned. This means the operating organization needs to incorporate appropriate measures to ensure the transfer of knowledge and expertise arising from the PSR via a contractor to the operation organization. It is desirable for the Regulatory Body to be involved in all stage of the PSR to prevent any waste of resources and minimize the potential for a reworking of the PSR and the need for an additional assessment and review as recommended by foreign experts.

  14. Radio Imaging Observations of PSR J1023+0038 in an LMXB State

    NARCIS (Netherlands)

    Deller, A.T.; Moldon, J.; Miller-Jones, J.C.A.; Patruno, A.; Hessels, J.W.T.; Archibald, A.M.; Paragi, Z.; Heald, G.; Vilchez, N.

    2015-01-01

    The transitional millisecond pulsar (MSP) binary system PSR J1023+0038 re-entered an accreting state in 2013 June in which it bears many similarities to low-mass X-ray binaries (LMXBs) in quiescence or near-quiescence. At a distance of just 1.37 kpc, PSR J1023+0038 offers an unsurpassed ability to

  15. On the nature of the intermittent pulsar PSR B1931+24

    NARCIS (Netherlands)

    Rea, N.; Kramer, M.; Stella, L.; Bassa, C. G.; Groot, P. J.; Israel, G. L.; Mendez, M.; Possenti, A.; Lyne, A.; Jonker, P.G.

    2008-01-01

    PSR B1931+24 is the first intermittent radio pulsar discovered to date, characterized by a 0.8-s pulsation, which turns on and off quasi-periodically every similar to 35 d, with a duty cycle of similar to 10 per cent. Here, we present X-ray and optical observations of PSR B1931+24 performed with the

  16. Phenotypic fitness effects of the selfish B chromosome, paternal sex ratio (PSR) in the parasitic wasp Nasonia vitripennis

    NARCIS (Netherlands)

    Beukeboom, Leo W.

    1994-01-01

    B chromosomes are often considered genomic parasites. Paternal sex ratio (PSR) is an extreme example of a parasitic B chromosome in the parasitoid wasp Nasonia vitripennis. PSR is transmitted through the sperm of carrier males and destroys the other paternal chromosomes in early fertilized eggs. PSR

  17. Phylogenetic distribution and membrane topology of the LytR-CpsA-Psr protein family

    Directory of Open Access Journals (Sweden)

    Berger-Bächi Brigitte

    2008-12-01

    Full Text Available Abstract Background The bacterial cell wall is the target of many antibiotics and cell envelope constituents are critical to host-pathogen interactions. To combat resistance development and virulence, a detailed knowledge of the individual factors involved is essential. Members of the LytR-CpsA-Psr family of cell envelope-associated attenuators are relevant for β-lactam resistance, biofilm formation, and stress tolerance, and they are suggested to play a role in cell wall maintenance. However, their precise function is still unknown. This study addresses the occurrence as well as sequence-based characteristics of the LytR-CpsA-Psr proteins. Results A comprehensive list of LytR-CpsA-Psr proteins was established, and their phylogenetic distribution and clustering into subgroups was determined. LytR-CpsA-Psr proteins were present in all Gram-positive organisms, except for the cell wall-deficient Mollicutes and one strain of the Clostridiales. In contrast, the majority of Gram-negatives did not contain LytR-CpsA-Psr family members. Despite high sequence divergence, the LytR-CpsA-Psr domains of different subclusters shared a highly similar, predicted mixed a/β-structure, and conserved charged residues. PhoA fusion experiments, using MsrR of Staphylococcus aureus, confirmed membrane topology predictions and extracellular location of its LytR-CpsA-Psr domain. Conclusion The LytR-CpsA-Psr domain is unique to bacteria. The presence of diverse subgroups within the LytR-CpsA-Psr family might indicate functional differences, and could explain variations in phenotypes of respective mutants reported. The identified conserved structural elements and amino acids are likely to be important for the function of the domain and will help to guide future studies of the LytR-CpsA-Psr proteins.

  18. PSR 0943+10: A Bare Strange Star?

    Science.gov (United States)

    Xu, R. X.; Qiao, G. J.; Zhang, Bing

    1999-09-01

    Recent work by Rankin & Deshpande strongly suggests that there exist strong ``microstorms'' rotating around the magnetic axis of the 1.1 s pulsar PSR 0943+10. Such a feature hints that most probably the large-voltage vacuum gap proposed by Ruderman & Sutherland (RS) does exist in the pulsar polar cap. However, there are severe arguments against the formation of the RS-type gap in pulsars, since the binding energies of both the 56Fe ions and the electrons in a neutron star's surface layer are too small to prevent thermionic ejection of the particles from the surface. Here we propose that PSR 0943+10 (and probably also all of the other ``drifting'' pulsars) might be bare strange stars rather than normal neutron stars, in which the ``binding energy'' at the surface is merely infinity for the case of either a ``pulsar'' or an ``antipulsar.'' It is further proposed that identifying a drifting pulsar as an antipulsar is the key criterion for distinguishing strange stars from neutron stars.

  19. High-energy Variability of PSR J1311-3430

    Science.gov (United States)

    An, Hongjun; Romani, Roger W.; Johnson, Tyrel; Kerr, Matthew; Clark, Colin J.

    2017-11-01

    We have studied the variability of the black-widow-type binary millisecond pulsar PSR J1311-3430 from optical to gamma-ray energies. We confirm evidence for orbital modulation in the weak off-pulse ≳200 MeV emission, with a peak at {φ }B≈ 0.8, following pulsar inferior conjunction. The peak has a relatively hard spectrum, extending above ˜1 GeV. XMM-Newton and Swift UV observations also show that this source’s strong X-ray flaring activity is associated with optical/UV flares. With a duty cycle of ˜7%-19%, this flaring is quite prominent with an apparent power-law intensity distribution. Flares are present at all orbital phases, with a slight preference for {φ }B=0.5{--}0.7. We explore possible connections of these variabilities with the intrabinary shock and magnetic activity on the low-mass secondary.

  20. The PSR 1800-21/G8.7-0.1 association: A view from ROSAT

    Science.gov (United States)

    Finley, John P.; Oegelman, Hakki

    1994-01-01

    We present the first imaging X-ray observation of the W30 complex which contains the Galactic SNR G8.7-0.1 and the young radio pulsar PSR 1800-21 as well as a number of discrete ultracompact H II regions. The pulsar PSR 1800-21 is detected as a count rate of 1.5 +/- 0.5/ks and diffuse emission from the northern extent of G8.7-0.1 observed. The data support an association of G8.7-0.1 and PSR 1800-21, and the peculiar morphology can be explained if the supernova which gave birth to PSR 1800-21 occurred within, or very near, a molecular cloud. The suggested scenario removes the requirement of a large transverse velocity for the pulsar, one of the greatest dificulties with the association.

  1. Large glitch from PSR 0355+54 and its post-glitch relaxation

    Energy Technology Data Exchange (ETDEWEB)

    Alpar, M.A.; Cheng, K.S.; Pines, David; Shaham, Jacob

    1988-07-01

    The recently observed large glitch of PSR 0355 + 54 and its post-glitch relaxation are interpreted within the vortex creep model applied previously to the post-glitch timing data for the Crab and Vela pulsars and for PSR 0525 + 21. A linear response regime of vortex creep is shown to explain the post-glitch observations and is likely to be operative in parts of the neutron star crust superfluid.

  2. A 1.05 M{sub ☉} companion to PSR J2222–0137: The coolest known white dwarf?

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, David L. [Department of Physics, University of Wisconsin-Milwaukee, 1900 East Kenwood Boulevard, Milwaukee, WI 53211 (United States); Boyles, Jason; McLaughlin, Maura A.; Lorimer, Duncan R. [Department of Physics and Astronomy, West Virginia University, White Hall, Box 6315, Morgantown, WV 26506-6315 (United States); Dunlap, Bart H. [Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC 27599-3255 (United States); Tendulkar, Shriharsh P. [Space Radiation Laboratory, California Institute of Technology, 1200 East California Boulevard, MC 249-17, Pasadena, CA 91125 (United States); Deller, Adam T. [ASTRON, P.O. Box 2, 7990 AA Dwingeloo (Netherlands); Ransom, Scott M. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475 (United States); Stairs, Ingrid H., E-mail: kaplan@uwm.edu [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia V6T 1Z1 (Canada)

    2014-07-10

    The recycled pulsar PSR J2222–0137 is one of the closest known neutron stars (NSs) with a parallax distance of 267{sub −0.9}{sup +1.2} pc and an edge-on orbit. We measure the Shapiro delay in the system through pulsar timing with the Green Bank Telescope, deriving a low pulsar mass (1.20 ± 0.14 M{sub ☉}) and a high companion mass (1.05 ± 0.06 M{sub ☉}) consistent with either a low-mass NS or a high-mass white dwarf. We can largely reject the NS hypothesis on the basis of the system's extremely low eccentricity (3 × 10{sup –4})—too low to have been the product of two supernovae under normal circumstances. However, despite deep optical and near-infrared searches with Southern Astrophysical Research and the Keck telescopes we have not discovered the optical counterpart of the system. This is consistent with the white dwarf hypothesis only if the effective temperature is <3000 K, a limit that is robust to distance, mass, and atmosphere uncertainties. This would make the companion to PSR J2222–0137 one of the coolest white dwarfs ever observed. For the implied age to be consistent with the age of the Milky Way requires the white dwarf to have already crystallized and entered the faster Debye-cooling regime.

  3. A 1.05 M ⊙ Companion to PSR J2222-0137: The Coolest Known White Dwarf?

    Science.gov (United States)

    Kaplan, David L.; Boyles, Jason; Dunlap, Bart H.; Tendulkar, Shriharsh P.; Deller, Adam T.; Ransom, Scott M.; McLaughlin, Maura A.; Lorimer, Duncan R.; Stairs, Ingrid H.

    2014-07-01

    The recycled pulsar PSR J2222-0137 is one of the closest known neutron stars (NSs) with a parallax distance of 267_{-0.9}^{+1.2} pc and an edge-on orbit. We measure the Shapiro delay in the system through pulsar timing with the Green Bank Telescope, deriving a low pulsar mass (1.20 ± 0.14 M ⊙) and a high companion mass (1.05 ± 0.06 M ⊙) consistent with either a low-mass NS or a high-mass white dwarf. We can largely reject the NS hypothesis on the basis of the system's extremely low eccentricity (3 × 10-4)—too low to have been the product of two supernovae under normal circumstances. However, despite deep optical and near-infrared searches with Southern Astrophysical Research and the Keck telescopes we have not discovered the optical counterpart of the system. This is consistent with the white dwarf hypothesis only if the effective temperature is <3000 K, a limit that is robust to distance, mass, and atmosphere uncertainties. This would make the companion to PSR J2222-0137 one of the coolest white dwarfs ever observed. For the implied age to be consistent with the age of the Milky Way requires the white dwarf to have already crystallized and entered the faster Debye-cooling regime.

  4. Fermi LAT Detection of Pulsed Gamma-Rays From the Vela-Like Pulsars PSR J1048-5832 and PSR J2229+6114

    Energy Technology Data Exchange (ETDEWEB)

    Abdo, A.A.; /Naval Research Lab, Wash., D.C. /Federal City Coll.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Atwood, W.B.; /UC, Santa Cruz; Axelsson, M.; /Stockholm U. /Stockholm U., OKC; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, G.; /INFN, Trieste /Trieste U.; Baring, M.G.; /Rice U.; Bastieri, D.; /INFN, Padua /Padua U.; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, R.; /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, E.D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Columbia U. /IASF, Milan /Milan Polytechnic /DAPNIA, Saclay /INFN, Perugia /Perugia U. /Naval Research Lab, Wash., D.C. /George Mason U. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /LPCE, Orleans /Montpellier U. /Stockholm U. /Stockholm U., OKC /INFN, Trieste /Bari U. /INFN, Bari /UC, Santa Cruz /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /CENBG, Gradignan /CENBG, Gradignan /Montpellier U. /Bari U. /INFN, Bari /INFN, Trieste /Arecibo Observ. /Hiroshima U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Bari U. /INFN, Bari /INFN, Bari /NASA, Goddard /Maryland U. /INFN, Perugia /Perugia U.; /more authors..

    2012-03-29

    We report the detection of {gamma}-ray pulsations ({ge}0.1 GeV) from PSR J2229+6114 and PSR J1048-5832, the latter having been detected as a low-significance pulsar by EGRET. Data in the {gamma}-ray band were acquired by the Large Area Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope, while the radio rotational ephemerides used to fold the {gamma}-ray light curves were obtained using the Green Bank Telescope, the Lovell telescope at Jodrell Bank, and the Parkes Telescope. The two young radio pulsars, located within the error circles of the previously unidentified EGRET sources 3EG J1048-5840 and 3EG J2227+6122, present spin-down characteristics similar to the Vela pulsar. PSR J1048-5832 shows two sharp peaks at phases 0.15 {+-} 0.01 and 0.57 {+-} 0.01 relative to the radio pulse confirming the EGRET light curve, while PSR J2229+6114 presents a very broad peak at phase 0.49 {+-} 0.01. The {gamma}-ray spectra above 0.1 GeV of both pulsars are fit with power laws having exponential cutoffs near 3 GeV, leading to integral photon fluxes of (2.19 {+-} 0.22 {+-} 0.32) x 10{sup -7} cm{sup -2} s{sup -1} for PSR J1048-5832 and (3.77 {+-} 0.22 {+-} 0.44) x 10{sup -7} cm{sup -2} s{sup -1} for PSR J2229+6114. The first uncertainty is statistical and the second is systematic. PSR J1048-5832 is one of the two LAT sources which were entangled together as 3EG J1048-5840. These detections add to the growing number of young {gamma}-ray pulsars that make up the dominant population of GeV {gamma}-ray sources in the Galactic plane.

  5. Deletion analysis of the selfish B chromosome, Paternal Sex Ratio (PSR), in the parasitic wasp Nasonia vitripennis

    NARCIS (Netherlands)

    Beukeboom, Leo W.; Werren, John H.

    1993-01-01

    Paternal Sex Ratio (PSR) is a “selfish” B chromosome in the parasitoid wasp Nasonia vitripennis. It is transmitted via sperm, but causes supercondensation and destruction of the paternal chromosomes in early fertilized eggs. Because this wasp has haplodiploid sex determination, the effect of PSR is

  6. Pulsed high-energy gamma rays from PSR 1055-52

    Science.gov (United States)

    Fierro, J. M.; Bertsch, D. L.; Brazier, K. T.; Chiang, J.; D'Amico, N.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Johnston, S.; Kanbach, G.

    1993-01-01

    The Energetic Gamma Ray Experiment Telescope (EGRET) aboard the Compton Gamma Ray Observatory has detected a high-energy gamma-ray source at a position coincident with that of the radio pulsar PSR 1055-52. Analysis of the EGRET data at the radio pulsar period of 197 ms has revealed pulsed gamma-radiation at energies above 300 MeV, making PSR 1055-52 the fifth detected high-energy gamma-ray pulsar. The pulsed radiation from PSR 1055-52 has a very hard photon spectral index of -1.18 +/- 0.16 and a high efficiency for converting its rotational energy into gamma-rays. No unpulsed emission was observed.

  7. Modelling time variable and total eclipses of the millisecond pulsar PSR 1744-24A

    Science.gov (United States)

    Tavani, Marco; Brookshaw, Leigh

    1993-01-01

    The 11 ms pulsar PSR 1744-24A in the globular clusters Terzan 5 is the first and only known example of a binary eclipsing pulsar showing time-variable eclipses with irregular and nonsymmetric eclipse patterns. Occasionally, the pulsar eclipse becomes total, and no radio emission is detected for an extended period of time. We present here numerical results of a hydrodynamical model aimed at explaining the remarkable eclipse properties of PSR 1744-24A. We show that the hydrodynamic time scale for the partial or total pulsar enshrouding is of order of the orbital period for a relatively large mass loss rate, in agreement with observations. The time-variable eclipse egress positions imply that the mass loss rate from the companion varies within one orbital period. Hydrodynamic modelling of the mass outflow of PSR 1744-24A is of crucial importance for the understanding of a class of millisecond pulsars whose radio emission might be occasionally or permanently quenched by mass outflows from their companions. The properties of PSR 1744-24A suggest a new way of studying millisecond pulsars involving radio, X-ray, gamma-ray, and optical observations.

  8. Population Genetics of a Parasitic Chromosome : Experimental Analysis of PSR in Subdivided Populations

    NARCIS (Netherlands)

    Beukeboom, Leo W.; Werren, John H.; Charlesworth, B.

    1992-01-01

    Nasonia vitripennis is a parasitoid wasp that harbors several non-Mendelian sex-ratio distorters. These include MSR (Maternal Sex Ratio), a cytoplasmic element that causes nearly all-female families, and PSR (Paternal Sex Ratio), a supernumerary chromosome that causes all-male families. As in other

  9. Transmission and expression of the parasitic paternal sex ratio (PSR) chromosome

    NARCIS (Netherlands)

    Beukeboom, Leo W.; Werren, John H.

    1993-01-01

    B-chromosomes are often considered genomic parasites. They are extra to the normal chromosomal complement, are unnecessary for survival of an individual, and are often inherited at higher than Mendelian rates. Paternal Sex Ratio (PSR) is an extreme example of a parasitic B-chromosome in the wasp

  10. The paternal-sex-ratio (PSR) chromosome in natural populations of Nasonia (Hymenoptera Chalcidoidea)

    NARCIS (Netherlands)

    Beukeboom, L.W.; Werren, J.H.

    2000-01-01

    Selfish genetic elements may be important in promoting evolutionary change. Paternal sex ratio (PSR) is a selfish B chromosome that causes all-male families in the haplodiploid parasitic wasp Nasonia vitripennis, by inducing paternal genome loss in fertilized eggs. The natural distribution and

  11. Similarities Between the Inner Solar System and the Planetary System of PSR B1257+12

    OpenAIRE

    Mazeh, Tsevi; Goldman, Itzhak

    1994-01-01

    We call attention to the surprising similarity between the newly discovered planetary system around PSR B1257+12 and the inner solar system. The similarity is in the ratios of the orbital radii and the masses of the three planets.

  12. Old but Still Warm: Far-UV Detection of PSR B0950+08

    Science.gov (United States)

    Pavlov, G. G.; Rangelov, B.; Kargaltsev, O.; Reisenegger, A.; Guillot, S.; Reyes, C.

    2017-11-01

    We report on a Hubble Space Telescope detection of the nearby, old pulsar B0950+08 (d≃ 262 pc, spin-down age 17.5 Myr) in two far-ultraviolet (FUV) bands. We measured the mean flux densities {\\bar{f}}ν =109+/- 6 nJy and 83 ± 14 nJy in the F125LP and F140LP filters (pivot wavelengths 1438 and 1528 Å). Using the FUV data together with previously obtained optical-UV data, we conclude that the optical-FUV spectrum consists of two components—a nonthermal (presumably magnetospheric) power-law spectrum ({f}ν \\propto {ν }α ) with slope α ˜ -1.2 and a thermal spectrum emitted from the bulk of the neutron star (NS) surface with a temperature in the range of (1-3) × 105 K, depending on interstellar extinction and NS radius. These temperatures are much higher than predicted by NS cooling models for such an old pulsar, which means that some heating mechanisms operate in NSs. A plausible mechanism responsible for the high temperature of PSR B0950+08 is the interaction of vortex lines of the faster rotating neutron superfluid with the slower rotating normal matter in the inner NS crust (vortex creep heating). Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program #13783.

  13. IDENTIFICATION OF THE OPTICAL COUNTERPART OF FERMI BLACK WIDOW MILLISECOND PULSAR PSR J1544+4937

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Sumin; Phinney, E. Sterl; Prince, Thomas A.; Bellm, Eric; Cao, Yi; Perley, Daniel A. [Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Kaplan, David L. [Physics Department, University of Wisconsin-Milwaukee, Milwaukee, WI 53211 (United States); Breton, Rene P. [School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom); Bildsten, Lars [Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106 (United States); Kong, Albert K. H.; Yen, T.-C. [Institute of Astronomy and Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Sesar, Branimir [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Wolf, William M. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States)

    2014-08-10

    We report the optical identification of the companion to the Fermi black widow millisecond pulsar PSR J1544+4937. We find a highly variable source on Keck Low Resolution Imaging Spectrometer images at the nominal pulsar position, with 2 mag variations over orbital period in the B, g, R, and I bands. The nearly achromatic light curves are difficult to explain with a simply irradiated hemisphere model, and suggest that the optical emission is dominated by a nearly isothermal hot patch on the surface of the companion facing the pulsar. We roughly constrain the distance to PSR J1544+4937 to be between 2 and 5 kpc. A more reliable distance measurement is needed in order to constrain the composition of the companion.

  14. X-ray properties of the mode-switching pulsar PSR B0943+10

    Science.gov (United States)

    Mereghetti, S.; Kuiper, L.; Tiengo, A.; Hessels, J.; Hermsen, W.; Stovall, K.; Possenti, A.; Rankin, J.; Esposito, P.; Turolla, R.; Mitra, D.; Wright, G.; Stappers, B.; Horneffer, A.; Oslowski, S.; Serylak, M.; Griessmeier, J.-M.; Rigoselli, M.

    2017-12-01

    The mode-switching pulsar PSR B0943+10 has been extensively studied in the radio band for many years and, more recently, it has been found to vary also in X-rays, with a flux anticorrelated with the radio emission. Here we review the results of long observations of PSR B0943+10 carried out with XMM-Newton and the LOFAR, LWA and Arecibo radio telescopes in 2014. These results support a scenario in which both unpulsed non-thermal emission, likely of magnetospheric origin, and pulsed thermal emission from a small polar cap (∼1500 m2) with a strong non-dipolar magnetic field (∼ 1014 G), are present during both radio modes and vary in intensity in a correlated way.

  15. The Extended X-ray Nebula of PSR J1420-6048

    Energy Technology Data Exchange (ETDEWEB)

    Van Etten, Adam; Romani, Roger W.; /Stanford U., Phys. Dept.

    2011-08-19

    The vicinity of the unidentified EGRET source 3EG J1420-6038 has undergone extensive study in the search for counterparts, revealing the energetic young pulsar PSR J1420-6048 and its surrounding wind nebula as a likely candidate for at least part of the emission from this bright and extended gamma-ray source. We report on new Suzaku observations of PSR J1420-6048, along with analysis of archival XMM Newton data. The low background of Suzaku permits mapping of the extended X-ray nebula, indicating a tail stretching {approx} 8 minutes north of the pulsar. The X-ray data, along with archival radio and VHE data, hint at a pulsar birthsite to the North, and yield insights into its evolution and the properties of the ambient medium. We further explore such properties by modeling the spectral energy distribution (SED) of the extended nebula.

  16. Performance, Scalability, and Reliability (PSR) challenges, metrics and tools for web testing : A Case Study

    OpenAIRE

    Magapu, Akshay Kumar; Yarlagadda, Nikhil

    2016-01-01

    Context. Testing of web applications is an important task, as it ensures the functionality and quality of web applications. The quality of web application comes under non-functional testing. There are many quality attributes such as performance, scalability, reliability, usability, accessibility and security. Among these attributes, PSR is the most important and commonly used attributes considered in practice. However, there are very few empirical studies conducted on these three attributes. ...

  17. PsrP, a Protective Pneumococcal Antigen, Is Highly Prevalent in Children with Pneumonia and Is Strongly Associated with Clonal Type ▿

    Science.gov (United States)

    Muñoz-Almagro, Carmen; Selva, Laura; Sanchez, Carlos J.; Esteva, Cristina; de Sevilla, Mariona F.; Pallares, Roman; Orihuela, Carlos J.

    2010-01-01

    Invasive pneumococcal disease (IPD) is a major health problem worldwide. Due to ongoing serotype replacement, current efforts are focused in an attempt to identify the pneumococcal antigens that could be used in a next-generation multivalent protein vaccine. The objective of our study was to use real-time PCR to determine the distribution and clonal type variability of PsrP, a protective pneumococcal antigen, among pneumococcal isolates from children with IPD or healthy nasopharyngeal carriers. psrP was detected in 52.4% of the 441 strains tested. While no differences were determined when the prevalence of psrP in colonizing strains (n = 89) versus that in all invasive strains (n = 352) was compared, a strong trend was observed when the prevalence of psrP in all pneumonia isolates (n = 209) and colonizing isolates (P = 0.067) was compared, and a significant difference was observed when the prevalence in all pneumonia isolates and those causing bacteremia (n = 76) was compared (P = 0.001). An age-dependent distribution of psrP was also observed, with the incidence of psrP being the greatest in strains isolated from children >2 years of age (P = 0.02). Strikingly, the presence of psrP within a serotype was highly dependent on the clonotype, with all isolates of invasive clones such as clonal complex 306 carrying psrP (n = 88), whereas for sequence type 304, only 1 of 19 isolates carried psrP; moreover, this was inversely correlated with antibiotic susceptibility. This finding suggests that inclusion of psrP in a vaccine formulation would not target resistant strains. We conclude that psrP is highly prevalent in strains that cause IPD but is most prevalent in strains isolated from older children with pneumonia. These data support the potential use of PsrP as one component in a multivalent protein-based vaccine. PMID:20861332

  18. FERMI LAT PULSED DETECTION OF PSR J0737-3039A IN THE DOUBLE PULSAR SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Guillemot, L.; Kramer, M. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany); Johnson, T. J. [National Research Council Research Associate, National Academy of Sciences, Washington, DC 20001 (United States); Craig, H. A.; Romani, R. W.; Kerr, M. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Venter, C. [Centre for Space Research, North-West University, Potchefstroom Campus, Private Bag X6001, 2520 Potchefstroom (South Africa); Harding, A. K. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Ferdman, R. D. [Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, The University of Manchester, M13 9PL (United Kingdom); Stairs, I. H., E-mail: guillemo@mpifr-bonn.mpg.de [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada)

    2013-05-10

    We report the Fermi Large Area Telescope discovery of {gamma}-ray pulsations from the 22.7 ms pulsar A in the double pulsar system J0737-3039A/B. This is the first mildly recycled millisecond pulsar (MSP) detected in the GeV domain. The 2.7 s companion object PSR J0737-3039B is not detected in {gamma} rays. PSR J0737-3039A is a faint {gamma}-ray emitter, so that its spectral properties are only weakly constrained; however, its measured efficiency is typical of other MSPs. The two peaks of the {gamma}-ray light curve are separated by roughly half a rotation and are well offset from the radio and X-ray emission, suggesting that the GeV radiation originates in a distinct part of the magnetosphere from the other types of emission. From the modeling of the radio and the {gamma}-ray emission profiles and the analysis of radio polarization data, we constrain the magnetic inclination {alpha} and the viewing angle {zeta} to be close to 90 Degree-Sign , which is consistent with independent studies of the radio emission from PSR J0737-3039A. A small misalignment angle between the pulsar's spin axis and the system's orbital axis is therefore favored, supporting the hypothesis that pulsar B was formed in a nearly symmetric supernova explosion as has been discussed in the literature already.

  19. A Model for the Challenging ``Bi-drifting'' Phenomenon in PSR J0815+09

    Science.gov (United States)

    Qiao, G. J.; Lee, K. J.; Zhang, B.; Xu, R. X.; Wang, H. G.

    2004-12-01

    A new drifting pulsar, PSR J0815+09, was discovered in the Arecibo drift-scan searches. An intriguing feature of this source is that within the four pulse components in the integrated pulse profile, the subpulse drifting direction in the two leading components is opposite from that in the two trailing components. In the view that the leading theoretical model for pulsar subpulse drifting can only interpret one-direction subpulse drifting, the observed bi-drifting phenomenon from PSR J0815+09 poses a great challenge to the pulsar theory. The inner annular gap (IAG), a new type of inner particle accelerator, was recently proposed to explain both γ-ray and radio emission from pulsars. Here we show that the coexistence of the IAG and the conventional inner core gap offers a natural interpretation to the bi-drifting phenomenon. In particular, the peculiar drifting behavior in PSR J0815+09 can be reproduced within the inverse Compton scattering model for pulsar radio emission.

  20. THE EINSTEIN-HOME SEARCH FOR RADIO PULSARS AND PSR J2007+2722 DISCOVERY

    Energy Technology Data Exchange (ETDEWEB)

    Allen, B.; Knispel, B.; Aulbert, C.; Bock, O.; Eggenstein, H. B.; Fehrmann, H.; Machenschalk, B. [Max-Planck-Institut fuer Gravitationsphysik, D-30167 Hannover (Germany); Cordes, J. M.; Brazier, A.; Chatterjee, S. [Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States); Deneva, J. S. [Arecibo Observatory, HC3 Box 53995, Arecibo, PR 00612 (United States); Hessels, J. W. T. [ASTRON, the Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA, Dwingeloo (Netherlands); Anderson, D. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Demorest, P. B. [NRAO (National Radio Astronomy Observatory), Charlottesville, VA 22903 (United States); Gotthelf, E. V. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Hammer, D. [Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, WI 53211 (United States); Kaspi, V. M. [Department of Physics, McGill University, Montreal, QC H3A2T8 (Canada); Kramer, M. [Max-Planck-Institut fuer Radioastronomie, D-53121 Bonn (Germany); Lyne, A. G. [Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL (United Kingdom); McLaughlin, M. A., E-mail: bruce.allen@aei.mpg.de [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States); and others

    2013-08-20

    Einstein-Home aggregates the computer power of hundreds of thousands of volunteers from 193 countries, to search for new neutron stars using data from electromagnetic and gravitational-wave detectors. This paper presents a detailed description of the search for new radio pulsars using Pulsar ALFA survey data from the Arecibo Observatory. The enormous computing power allows this search to cover a new region of parameter space; it can detect pulsars in binary systems with orbital periods as short as 11 minutes. We also describe the first Einstein-Home discovery, the 40.8 Hz isolated pulsar PSR J2007+2722, and provide a full timing model. PSR J2007+2722's pulse profile is remarkably wide with emission over almost the entire spin period. This neutron star is most likely a disrupted recycled pulsar, about as old as its characteristic spin-down age of 404 Myr. However, there is a small chance that it was born recently, with a low magnetic field. If so, upper limits on the X-ray flux suggest but cannot prove that PSR J2007+2722 is at least {approx}100 kyr old. In the future, we expect that the massive computing power provided by volunteers should enable many additional radio pulsar discoveries.

  1. Fermi LAT Pulsed Detection of PSR J0737-3039A in the Double Pulsar System

    Science.gov (United States)

    Guillemot, L.; Kramer, M.; Johnson, T. J.; Craig, H. A.; Romani, R. W.; Venter, C.; Harding, A. K.; Ferdman, R. D.; Stairs, I. H.; Kerr, M.

    2013-01-01

    We report the Fermi Large Area Telescope discovery of gamma-ray pulsations from the 22.7 ms pulsar A in the double pulsar system J0737-3039A/B. This is the first mildly recycled millisecond pulsar (MSP) detected in the GeV domain. The 2.7 s companion object PSR J0737-3039B is not detected in gamma rays. PSR J0737-3039A is a faint gamma-ray emitter, so that its spectral properties are only weakly constrained; however, its measured efficiency is typical of other MSPs. The two peaks of the gamma-ray light curve are separated by roughly half a rotation and are well offset from the radio and X-ray emission, suggesting that the GeV radiation originates in a distinct part of the magnetosphere from the other types of emission. From the modeling of the radio and the gamma-ray emission profiles and the analysis of radio polarization data, we constrain the magnetic inclination alpha and the viewing angle zeta to be close to 90 deg., which is consistent with independent studies of the radio emission from PSR J0737-3039A. A small misalignment angle between the pulsar's spin axis and the system's orbital axis is therefore favored, supporting the hypothesis that pulsar B was formed in a nearly symmetric supernova explosion as has been discussed in the literature already.

  2. High Frequency Radio Observations of the Reactivated Magnetar PSR J1622-4950

    Science.gov (United States)

    Pearlman, Aaron B.; Majid, Walid A.; Prince, Thomas A.; Horiuchi, Shinji; Kocz, Jonathon; Lazio, T. J. W.; Naudet, Charles J.

    2017-07-01

    Radio emission from the magnetar PSR J1622-4950 was recently reported to have resumed (Camilo et al., ATel #10346). We have carried out Target of Opportunity (ToO) radio observations of PSR J1622-4950 at S-band (2.3 GHz) and X-band (8.4 GHz) using the 70-m diameter Deep Space Network (DSN) radio dish (DSS-43) in Canberra, Australia. We report on our single polarization mode observations of PSR J1622-4950 spanning 5 hours on 23 May 2017 starting at 16:03:32 UTC. Pulsations were detected at a period of 4.327308(1) s. We measure a mean flux density of 3.8(8)/0.41(8) mJy at S/X-band, from which we derive a spectral index of -1.7(2). We note that PSR J1622-4950's spectral behavior is now consistent with the majority of pulsars, which have a mean spectral index of -1.8(2) (Maron et al. (2000)). The result by Maron et al. (2000) is used here because they included more high frequency pulsar spectra than other studies to characterize the underlying spectral index distribution over a wide frequency range. The mean flux density at S-band has now increased by an order of magnitude compared to previous flux density measurements by Scholz et al. (2017) during the magnetar's quiescent state. Furthermore, the spectral index has steepened compared to a nearly flat spectral index from flux density measurements between 1.4 and 24 GHz prior to the disappearance of the radio emission (Levin et al. (2010); Keith et al. (2011); Levin et al. (2012); Anderson et al. (2012); Scholz et al. (2017)). We are continuing to monitor changes in PSR J1622-4950's radio spectrum at both S-band and X-band. We thank the DSN (Deep Space Network) and Canberra Deep Space Communication Complex (CDSCC) teams for scheduling these observations.

  3. Intra-particle migration of mercury in granular polysulfide-rubber-coated activated carbon (PSR-AC).

    Science.gov (United States)

    Kim, Eun-Ah; Masue-Slowey, Yoko; Fendorf, Scott; Luthy, Richard G

    2012-02-01

    The depth profile of mercuric ion after the reaction with polysulfide-rubber-coated activated carbon (PSR-AC) was investigated using micro-X-ray fluorescence (μ-XRF) imaging techniques and mathematical modeling. The μ-XRF results revealed that mercury was concentrated at 0-100 μm from the exterior of the particle after 3 months of treatment with PSR-AC in 10 ppm HgCl(2) aqueous solution. The μ-X-ray absorption near edge spectroscopic (μ-XANES) analyses indicated HgS as a major mercury species, and suggested that the intra-particle mercury transport involved a chemical reaction with PSR polymer. An intra-particle mass transfer model was developed based on either a Langmuir sorption isotherm with liquid phase diffusion (Langmuir model) or a kinetic sorption with surface diffusion (kinetic sorption model). The Langmuir model predicted the general trend of mercury diffusion, although at a slower rate than observed from the μ-XRF map. A kinetic sorption model suggested faster mercury transport, which overestimated the movement of mercuric ions through an exchange reaction between the fast and slow reaction sites. Both μ-XRF and mathematical modeling results suggest mercury removal occurs not only at the outer surface of the PSR-AC particle but also at some interior regions due to a large PSR surface area within an AC particle. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Effects of Smoking and Genotype on the PSR Index of Periodontal Disease in Adults Aged 18–49

    Science.gov (United States)

    Polk, Deborah E.; Wang, Xiaojing; Feingold, Eleanor; Shaffer, John R.; Weeks, Daniel E.; Weyant, Robert J.; Crout, Richard J.; McNeil, Daniel W.; Marazita, Mary L.

    2012-01-01

    Studies have found both genetic and environmental influences on chronic periodontitis. The purpose of this study was to examine the relationships among previously identified genetic variants, smoking status, and two periodontal disease-related phenotypes (PSR1 and PSR2) in 625 Caucasian adults (aged 18–49 years). The PSR Index was used to classify participants as affected or unaffected under the PSR1 and PSR2 phenotype definitions. Using logistic regression, we found that the form of the relationship varied by single nucleotide polymorphism (SNP): For rs10457525 and rs12630931, the effects of smoking and genotype on risk were additive; whereas for rs10457526 and rs733048, smoking was not independently associated with affected status once genotype was taken into consideration. In contrast, smoking moderated the relationships of rs3870371 and rs733048 with affected status such that former and never smokers with select genotypes were at increased genetic risk. Thus, for several groups, knowledge of genotype may refine the risk prediction over that which can be determined by knowledge of smoking status alone. Future studies should replicate these findings. These findings provide the foundation for the exploration of novel pathways by which periodontitis may occur. PMID:23066400

  5. Effects of smoking and genotype on the PSR index of periodontal disease in adults aged 18-49.

    Science.gov (United States)

    Polk, Deborah E; Wang, Xiaojing; Feingold, Eleanor; Shaffer, John R; Weeks, Daniel E; Weyant, Robert J; Crout, Richard J; McNeil, Daniel W; Marazita, Mary L

    2012-08-01

    Studies have found both genetic and environmental influences on chronic periodontitis. The purpose of this study was to examine the relationships among previously identified genetic variants, smoking status, and two periodontal disease-related phenotypes (PSR1 and PSR2) in 625 Caucasian adults (aged 18-49 years). The PSR Index was used to classify participants as affected or unaffected under the PSR1 and PSR2 phenotype definitions. Using logistic regression, we found that the form of the relationship varied by single nucleotide polymorphism (SNP): For rs10457525 and rs12630931, the effects of smoking and genotype on risk were additive; whereas for rs10457526 and rs733048, smoking was not independently associated with affected status once genotype was taken into consideration. In contrast, smoking moderated the relationships of rs3870371 and rs733048 with affected status such that former and never smokers with select genotypes were at increased genetic risk. Thus, for several groups, knowledge of genotype may refine the risk prediction over that which can be determined by knowledge of smoking status alone. Future studies should replicate these findings. These findings provide the foundation for the exploration of novel pathways by which periodontitis may occur.

  6. DISCOVERY OF GAMMA-RAY PULSATIONS FROM THE TRANSITIONAL REDBACK PSR J1227-4853

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, T. J. [College of Science, George Mason University, Fairfax, VA 22030 (United States); Ray, P. S.; Cheung, C. C. [Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352 (United States); Roy, J.; Bhattacharyya, B.; Stappers, B. W. [Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL (United Kingdom); Harding, A. K. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Pletsch, H. J.; Fort, S. [Albert-Einstein-Institut, Max-Planck-Institut für Gravitationsphysik, D-30167 Hannover (Germany); Camilo, F. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Deneva, J. [National Research Council Research Associate, National Academy of Sciences, Washington, DC 20001 (United States); Kerr, M., E-mail: tyrel.j.johnson@gmail.com, E-mail: Paul.Ray@nrl.navy.mil, E-mail: jayanta.roy@manchester.ac.uk [CSIRO Astronomy and Space Science, Australia Telescope National Facility, Epping NSW 1710 (Australia)

    2015-06-10

    The 1.69 ms spin period of PSR J1227−4853 was recently discovered in radio observations of the low-mass X-ray binary XSS J12270−4859 following the announcement of a possible transition to a rotation-powered millisecond pulsar state, inferred from decreases in optical, X-ray, and gamma-ray flux from the source. We report the detection of significant (5σ) gamma-ray pulsations after the transition, at the known spin period, using ∼1 year of data from the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. The gamma-ray light curve of PSR J1227−4853 can be fit by one broad peak, which occurs at nearly the same phase as the main peak in the 1.4 GHz radio profile. The partial alignment of light-curve peaks in different wavebands suggests that at least some of the radio emission may originate at high altitude in the pulsar magnetosphere, in extended regions co-located with the gamma-ray emission site. We folded the LAT data at the orbital period, both pre- and post-transition, but find no evidence for significant modulation of the gamma-ray flux. Analysis of the gamma-ray flux over the mission suggests an approximate transition time of 2012 November 30. Continued study of the pulsed emission and monitoring of PSR J1227−4853, and other known redback systems, for subsequent flux changes will increase our knowledge of the pulsar emission mechanism and transitioning systems.

  7. SPECTROSCOPY OF THE INNER COMPANION OF THE PULSAR PSR J0337+1715

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, David L. [Department of Physics, University of Wisconsin-Milwaukee, 1900 E. Kenwood Boulevard, Milwaukee, WI 53211 (United States); Van Kerkwijk, Marten H. [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H8 (Canada); Koester, Detlev [Institut für Theoretische Physik und Astrophysik, University of Kiel, D-24098 Kiel (Germany); Stairs, Ingrid H. [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia V6T 1Z1 (Canada); Ransom, Scott M. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475 (United States); Archibald, Anne M.; Hessels, Jason W. T. [ASTRON, the Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA Dwingeloo (Netherlands); Boyles, Jason, E-mail: kaplan@uwm.edu, E-mail: mhvk@astro.utoronto.ca [Department of Physics and Astronomy, West Virginia University, White Hall, Box 6315, Morgantown, WV 26506-6315 (United States)

    2014-03-01

    The hierarchical triple system PSR J0337+1715 offers an unprecedented laboratory to study secular evolution of interacting systems and to explore the complicated mass-transfer history that forms millisecond pulsars and helium-core white dwarfs. The latter in particular, however, requires knowledge of the properties of the individual components of the system. Here we present precise optical spectroscopy of the inner companion in the PSR J0337+1715 system. We confirm it as a hot, low-gravity DA white dwarf with T {sub eff} = 15, 800 ± 100 K and log{sub 10}(g) = 5.82 ± 0.05. We also measure an inner mass ratio of 0.1364 ± 0.0015, entirely consistent with that inferred from pulsar timing, and a systemic radial velocity of 29.7 ± 0.3 km s{sup –1}. Combined with the mass (0.19751 M {sub ☉}) determined from pulsar timing, our measurement of the surface gravity implies a radius of 0.091 ± 0.005 R {sub ☉}; combined further with the effective temperature and extinction, the photometry implies a distance of 1300 ± 80 pc. The high temperature of the companion is somewhat puzzling: with current models, it likely requires a recent period of unstable hydrogen burning, and suggests a surprisingly short lifetime for objects at this phase in their evolution. We discuss the implications of these measurements in the context of understanding the PSR J0337+1715 system, as well as of low-mass white dwarfs in general.

  8. Suzaku Observations of PSR B1259-63: A New Manifestation of Relativistic Pulsar Wind

    Energy Technology Data Exchange (ETDEWEB)

    Uchiyama, Yasunobu; Tanaka, Takaaki; Takahashi, Tadayuki; Mori, Koji; Nakazawa, Kazuhiro

    2009-04-27

    We observed PSR B1259-63, a young non-accreting pulsar orbiting around a Be star SS 2883, eight times with the Suzaku satellite from July to September 2007, to characterize the X-ray emission arising from the interaction between a pulsar relativistic wind and Be star outflows. The X-ray spectra showed a featureless continuum in 0.6-10 keV, modeled by a power law with a wide range of photon index 1.3-1.8. When combined with the Suzaku PIN detector which allowed spectral analysis in the hard 15-50 keV band, X-ray spectra do show a break at {approx} 5 keV in a certain epoch. Regarding the PSR B1259-63 system as a compactified pulsar wind nebula, in which e{sup {+-}} pairs are assumed to be accelerated at the inner shock front of the pulsar wind, we attribute the X-ray spectral break to the low-energy cutoff of the synchrotron radiation associated with the Lorentz factor of the relativistic pulsar wind {gamma}{sub 1} {approx} 4 x 10{sup 5}. Our result indicates that Comptonization of stellar photons by the unshocked pulsar wind will be accessible (or tightly constrained) by observations with the Fermi Gamma-ray Space Telescope during the next periastron passage. The PSR B1259-63 system allows us to probe the fundamental properties of the pulsar wind by a direct means, being complementary to the study of large-scale pulsar wind nebulae.

  9. PSR J1723-2837: An Eclipsing Binary Radio Millisecond Pulsar

    Science.gov (United States)

    Crawford, Fronefield; Lyne, Andrew G.; Stairs, Ingrid H.; Kaplan, David L.; McLaughlin, Maura A.; Freire, Paulo C. C.; Burgay, Marta; Camilo, Fernando; D'Amico, Nichi; Faulkner, Andrew; Kramer, Michael; Lorimer, Duncan R.; Manchester, Richard N.; Possenti, Andrea; Steeghs, Danny

    2013-10-01

    We present a study of PSR J1723-2837, an eclipsing, 1.86 ms millisecond binary radio pulsar discovered in the Parkes Multibeam survey. Radio timing indicates that the pulsar has a circular orbit with a 15 hr orbital period, a low-mass companion, and a measurable orbital period derivative. The eclipse fraction of ~15% during the pulsar's orbit is twice the Roche lobe size inferred for the companion. The timing behavior is significantly affected by unmodeled systematics of astrophysical origin, and higher-order orbital period derivatives are needed in the timing solution to account for these variations. We have identified the pulsar's (non-degenerate) companion using archival ultraviolet, optical, and infrared survey data and new optical photometry. Doppler shifts from optical spectroscopy confirm the star's association with the pulsar and indicate a pulsar-to-companion mass ratio of 3.3 ± 0.5, corresponding to a companion mass range of 0.4 to 0.7 M ⊙ and an orbital inclination angle range of between 30° and 41°, assuming a pulsar mass range of 1.4-2.0 M ⊙. Spectroscopy indicates a spectral type of G for the companion and an inferred Roche-lobe-filling distance that is consistent with the distance estimated from radio dispersion. The features of PSR J1723-2837 indicate that it is likely a "redback" system. Unlike the five other Galactic redbacks discovered to date, PSR J1723-2837 has not been detected as a γ-ray source with Fermi. This may be due to an intrinsic spin-down luminosity that is much smaller than the measured value if the unmeasured contribution from proper motion is large.

  10. PSR J1723–2837: AN ECLIPSING BINARY RADIO MILLISECOND PULSAR

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, Fronefield [Department of Physics and Astronomy, Franklin and Marshall College, P.O. Box 3003, Lancaster, PA 17604 (United States); Lyne, Andrew G. [Jodrell Bank Centre for Astrophysics, University of Manchester, Manchester M13 9PL (United Kingdom); Stairs, Ingrid H. [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Kaplan, David L. [Physics Department, University of Wisconsin - Milwaukee, Milwaukee, WI 53211 (United States); McLaughlin, Maura A.; Lorimer, Duncan R. [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States); Freire, Paulo C. C.; Kramer, Michael [Max-Planck-Institut für Radioastronomie, auf dem Huegel 69, D-53121 Bonn (Germany); Burgay, Marta; D' Amico, Nichi; Possenti, Andrea [INAF - Osservatorio Astronomico di Cagliari, Poggio dei Pini, I-09012 Capoterra (Italy); Camilo, Fernando [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Faulkner, Andrew [Cavendish Laboratory, University of Cambridge, J. J. Thompson Avenue, Cambridge, CB3 0HE (United Kingdom); Manchester, Richard N. [CSIRO Astronomy and Space Science, Australia Telescope National Facility, P.O. Box 76, Epping, NSW 1710 (Australia); Steeghs, Danny, E-mail: fcrawfor@fandm.edu [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom)

    2013-10-10

    We present a study of PSR J1723–2837, an eclipsing, 1.86 ms millisecond binary radio pulsar discovered in the Parkes Multibeam survey. Radio timing indicates that the pulsar has a circular orbit with a 15 hr orbital period, a low-mass companion, and a measurable orbital period derivative. The eclipse fraction of ∼15% during the pulsar's orbit is twice the Roche lobe size inferred for the companion. The timing behavior is significantly affected by unmodeled systematics of astrophysical origin, and higher-order orbital period derivatives are needed in the timing solution to account for these variations. We have identified the pulsar's (non-degenerate) companion using archival ultraviolet, optical, and infrared survey data and new optical photometry. Doppler shifts from optical spectroscopy confirm the star's association with the pulsar and indicate a pulsar-to-companion mass ratio of 3.3 ± 0.5, corresponding to a companion mass range of 0.4 to 0.7 M{sub ☉} and an orbital inclination angle range of between 30° and 41°, assuming a pulsar mass range of 1.4-2.0 M{sub ☉}. Spectroscopy indicates a spectral type of G for the companion and an inferred Roche-lobe-filling distance that is consistent with the distance estimated from radio dispersion. The features of PSR J1723–2837 indicate that it is likely a 'redback' system. Unlike the five other Galactic redbacks discovered to date, PSR J1723–2837 has not been detected as a γ-ray source with Fermi. This may be due to an intrinsic spin-down luminosity that is much smaller than the measured value if the unmeasured contribution from proper motion is large.

  11. Monitoring PSR B1509–58 with RXTE: Spectral analysis 1996–2010

    Directory of Open Access Journals (Sweden)

    E. Litzinger

    2011-01-01

    Full Text Available We present an analysis of the X-ray spectra of the young, Crab-like pulsar PSR B1509–58 (pulse period P ~ 151ms observed by RXTE over 14 years since the beginning of the mission in 1996. The uniform dataset is especially well suited for studying the stability of the spectral parameters over time as well as for determining pulse phase resolved spectral parameters with high significance. The phase averaged spectra as well as the resolved spectra can be well described by an absorbed power law.

  12. Nature and evolution of the eclipsing millisecond binary pulsar PSR1957 + 20

    Science.gov (United States)

    Kluzniak, W.; Ruderman, M.; Shaham, J.; Tavani, M.

    1988-01-01

    A model in which a millisecond pulsar may be able to evaporate a very light companion by a particular component of its energetic radiation is applied to the recently discovered 1.6-ms pulsar PSR1957 + 20. Pulsar turn-on in the very low-mass X-ray binary follows a stage of mass transfer dominated by an evaporative wind from the surface of the companion. The wind is driven by a large MeV gamma-ray flux powered by an accretion dynamo. That source of radiation ceases when it is replaced by that from the millisecond pulsar, which has been spun up by accretion.

  13. PSR B2111+46: a test of the inverse Compton scattering model of radio emission

    Science.gov (United States)

    Zhang, H.; Qiao, G. J.; Han, J. L.; Lee, K. J.; Wang, H. G.

    2007-04-01

    The region in which pulsars radiate is very important to constrain pulsar emission mechanisms. A three-dimensional (3D) method to calculate emission heights is developed in this paper. As an example, radiation regions for different components at different frequencies have been calculated for PSR B2111+46. Emission components at seven frequencies are fitted with Gaussian components, then the radiation heights for emission components are calculated. We found that different emission components, even if at the same radio frequency, are radiated from different heights. This is probably a common phenomena and challenges any emission mechanisms. The inverse Compton scattering emission model for pulsar radio emission can explain these results well.

  14. Radio and γ-ray Constraints on the Emission Geometry and Birthplace of PSR J2043+2740

    Science.gov (United States)

    Noutsos, A.; Abdo, A. A.; Ackermann, M.; Ajello, M.; Ballet, J.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bonamente, E.; Borgland, A. W.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Buehler, R.; Busetto, G.; Caliandro, G. A.; Cameron, R. A.; Camilo, F.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Çelik, Ö.; Chaty, S.; Chekhtman, A.; Chiang, J.; Ciprini, S.; Claus, R.; Cognard, I.; Cohen-Tanugi, J.; Colafrancesco, S.; Cutini, S.; Dermer, C. D.; de Palma, F.; Drell, P. S.; Dumora, D.; Ea, C. M.; Favuzzi, C.; Ferrara, E. C.; Focke, W. B.; Frailis, M.; Freire, P. C. C.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Germani, S.; Giglietto, N.; Giordano, F.; Giroletti, M.; Godfrey, G.; Grandi, P.; Grenier, I. A.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Harding, A. K.; Hughes, R. E.; Jackson, M. S.; Jóhannesson, G.; Johnson, A. S.; Johnson, T. J.; Johnson, W. N.; Johnston, S.; Kamae, T.; Katagiri, H.; Kataoka, J.; Knödlseder, J.; Kramer, M.; Kuss, M.; Lande, J.; Lee, S.-H.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Lyne, A. G.; Makeev, A.; Marelli, M.; Mazziotta, M. N.; McEnery, J. E.; Mehault, J.; Michelson, P. F.; Mizuno, T.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Naumann-Godo, M.; Nolan, P. L.; Nuss, E.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orlando, E.; Ormes, J. F.; Panetta, J. H.; Parent, D.; Pelassa, V.; Pepe, M.; Persic, M.; Pesce-Rollins, M.; Piron, F.; Porter, T. A.; Rainò, S.; Ray, P. S.; Razzano, M.; Reimer, A.; Reimer, O.; Reposeur, T.; Romani, R. W.; Sadrozinski, H. F.-W.; Sander, A.; Saz Parkinson, P. M.; Sgrò, C.; Siskind, E. J.; Smith, D. A.; Smith, P. D.; Spandre, G.; Spinelli, P.; Stappers, B. W.; Strickman, M. S.; Suson, D. J.; Takahashi, H.; Tanaka, T.; Theureau, G.; Thompson, D. J.; Thorsett, S. E.; Tibolla, O.; Torres, D. F.; Tramacere, A.; Usher, T. L.; Vandenbroucke, J.; Vianello, G.; Vilchez, N.; Villata, M.; Vitale, V.; von Kienlin, A.; Waite, A. P.; Wang, P.; Watters, K.; Weltevrede, P.; Winer, B. L.; Wood, K. S.; Ziegler, M.

    2011-02-01

    We report on the first year of Fermi γ-ray observations of pulsed high-energy emission from the old PSR J2043 + 2740. The study of the γ-ray efficiency of such old pulsars gives us an insight into the evolution of pulsars' ability to emit in γ rays as they age. The γ-ray light curve of this pulsar above 0.1 GeV is clearly defined by two sharp peaks, 0.353 ± 0.035 periods apart. We have combined the γ-ray profile characteristics of PSR J2043 + 2740 with the geometrical properties of the pulsar's radio emission, derived from radio-polarization data, and constrained the pulsar-beam geometry in the framework of a two-pole caustic (TPC) and an outer gap (OG) model. The ranges of magnetic inclination and viewing angle were determined to be {α, ζ} ~ {52°-57°, 61°-68°} for the TPC model, and {α, ζ} ~ {62°-73°, 74°-81°} and {α, ζ} ~ {72°-83°, 60°-75°} for the OG model. Based on this geometry, we assess possible birth locations for this pulsar and derive a likely proper motion, sufficiently high to be measurable with VLBI. At a characteristic age of 1.2 Myr, PSR J2043 + 2740 is the third oldest of all discovered, non-recycled, γ-ray pulsars: it is twice as old as the next oldest, PSR J0357 + 32, and younger only than the recently discovered PSR J1836 + 5925 and PSR J2055 + 25, both of which are at least five and ten times less energetic, respectively.

  15. Mitigation of the electron-cloud effect in the PSR and SNS protonstorage rings by tailoring the bunch profile

    CERN Document Server

    Pivi, M T

    2003-01-01

    For the storage ring of the Spallation Neutron Source (SNS) at Oak Ridge, and for the Proton Storage Ring (PSR) at Los Alamos, both with intense and very long bunches, the electron cloud develops primarily by the mechanism of trailing-edge multipacting. We show, by means of simulations for the PSR, how the resonant nature of this mechanism may be effectively broken by tailoring the longitudinal bunch profile at fixed bunch charge, resulting in a significant decrease in the electron-cloud effect. We briefly discuss the experimental difficulties expected in the implementation of this cure.

  16. Binary-binary interactions and the formation of the PSR B1620-26 triple system in M4

    Science.gov (United States)

    Rasio, Frederic A.; Mcmillan, Steve; Hut, Piet

    1995-01-01

    The hierarchical triple system containing the millisecond pulsar PSR B1620-26 in M4 is the first star system ever detected in a globular cluster. Such systems should form in globular clusters as a result of dynamical interactions between binaries. We propose that the triple system containing PSR B1620-26 formed through an exchange interaction between a wide primordial binary and a pre-existing binary millisecond pulsar. This scenario would have the advantage of reconciling the approximately 10(exp 9) yr timing age of the pulsar with the much shorter lifetime of the triple system in the core of M4.

  17. DISCOVERY OF GAMMA-RAY ORBITAL MODULATION IN THE BLACK WIDOW PSR J1311–3430

    Energy Technology Data Exchange (ETDEWEB)

    Xing, Yi; Wang, Zhongxiang [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China)

    2015-05-10

    We report our discovery of orbitally modulated γ-ray emission from the black widow system PSR J1311−3430. We analyze the Fermi Large Area Telescope data during the off-pulse phase interval of the pulsar and find the orbital modulation signal at a ∼3σ confidence level. Further spectral analysis shows no significant differences for the spectra obtained during the bright and faint orbital phase ranges. A simple sinusoid-like function can describe the modulation. Given these properties, we suggest that the intrabinary γ-ray emission arises from the region close to the companion and the modulation is caused by the occultation of the emitting region by the companion, similar to that is seen in the transitional millisecond pulsar binary (MSP) PSR J1023+0038. Considering the X-ray detection of intrabinary shock emission from eclipsing MSP binaries recently reported, this discovery further suggests the general existence of intrabinary γ-ray emission from them.

  18. MODELING MULTI-WAVELENGTH PULSE PROFILES OF THE MILLISECOND PULSAR PSR B1821–24

    Energy Technology Data Exchange (ETDEWEB)

    Du, Yuanjie; Shuai, Ping; Bei, Xiaomin; Chen, Shaolong; Fu, Linzhong; Huang, Liangwei; Lin, Qingqing; Meng, Jing; Wu, Yaojun; Zhang, Hengbin; Zhang, Qian; Zhang, Xinyuan [Qian Xuesen Laboratory of Space Technology, NO. 104, Youyi Road, Haidian District, Beijing 100094 (China); Qiao, Guojun, E-mail: dyj@nao.cas.cn [School of Physics, Peking University, Beijing 100871 (China)

    2015-03-10

    PSR B1821–24 is a solitary millisecond pulsar that radiates multi-wavelength pulsed photons. It has complex radio, X-ray, and γ-ray pulse profiles with distinct peak phase separations that challenge the traditional caustic emission models. Using the single-pole annular gap model with a suitable magnetic inclination angle (α = 40°) and viewing angle (ζ = 75°), we managed to reproduce its pulse profiles of three wavebands. It is found that the middle radio peak originated from the core gap region at high altitudes, and the other two radio peaks originated from the annular gap region at relatively low altitudes. Two peaks of both X-ray and γ-ray wavebands basically originated from the annular gap region, while the γ-ray emission generated from the core gap region contributes somewhat to the first γ-ray peak. Precisely reproducing the multi-wavelength pulse profiles of PSR B1821–24 enables us to understand emission regions of distinct wavebands and justify pulsar emission models.

  19. Study the Rheological and Mechanical Properties of PSR / NR Rubber Blends

    Directory of Open Access Journals (Sweden)

    Ammar Al-Kawaz

    2017-12-01

    Full Text Available  A perfect adhesion between the rubber of a tire and the reinforcing polymeric cord is crucial for the overall tire performance and safety. The problem of bonding rubber to textile cords is due to the big difference between the surface properties. Blending of polymers has obtained much attention because, it can be used to obtain new polymeric materials with particular properties suitable for some special purposes. The blends of Natural rubber (NR / Polysulfide rubber (PSR has been prepared with a verity weight ratios (100/0, 90/10, 80/20, 60/40. The characteristics of the prepared blends were investigated, such as rheological, mechanical and damping properties. It was found that the increasing of the weight percent of PSR in the blend compositions leads to the increase its adhesive strength with nylon 66 cord and also increase the hardness of the resultant blends. On the other hand, the curing time, tensile strength, elongation at break and rebound resilience were decreased.

  20. Realistic modeling of the pulse profile of PSR J0737-3039A

    Energy Technology Data Exchange (ETDEWEB)

    Perera, B. B. P.; Kim, C.; McLaughlin, M. A. [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States); Ferdman, R. D. [Department of Physics, McGill University, Ernest Rutherford Physics Building, 3600 University Street, Montreal, QC H3A 2T8 (Canada); Kramer, M.; Freire, P. C. C. [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Stairs, I. H. [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia V6T 1Z1 (Canada); Possenti, A. [INAF-Osservatorio Astronomica di Cagliari, Loc. Poggio dei Pini, Strada 54, I-09012 Capoterra (Italy)

    2014-05-20

    The Double Pulsar, PSR J0737-3039A/B, is a unique system in which both neutron stars have been detected as radio pulsars. As shown in Ferdman et al., there is no evidence for pulse profile evolution of the A pulsar, and the geometry of the pulsar was fit well with a double-pole circular radio beam model. Assuming a more realistic polar cap model with a vacuum retarded dipole magnetosphere configuration including special relativistic effects, we create synthesized pulse profiles for A given the best-fit geometry from the simple circular beam model. By fitting synthesized pulse profiles to those observed from pulsar A, we constrain the geometry of the radio beam, namely the half-opening angle and the emission altitude, to be ∼30° and ∼10 neutron star radii, respectively. Combining the observational constraints of PSR J0737-3039A/B, we are able to construct the full three-dimensional orbital geometry of the Double Pulsar. The relative angle between the spin axes of the two pulsars (Δ{sub S}) is estimated to be ∼(138° ± 5°) at the current epoch and will likely remain constant until tidal interactions become important in ∼85 Myr, at merger.

  1. Remaining Useful Life Prediction of Rolling Bearings Using PSR, JADE, and Extreme Learning Machine

    Directory of Open Access Journals (Sweden)

    Yongbin Liu

    2016-01-01

    Full Text Available Rolling bearings play a pivotal role in rotating machinery. The degradation assessment and remaining useful life (RUL prediction of bearings are critical to condition-based maintenance. However, sensitive feature extraction still remains a formidable challenge. In this paper, a novel feature extraction method is introduced to obtain the sensitive features through phase space reconstitution (PSR and joint with approximate diagonalization of Eigen-matrices (JADE. Firstly, the original features are extracted from bearing vibration signals in time and frequency domain. Secondly, the PSR is applied to embed the original features into high dimensional phase space. The between-class and within-class scatter (SS are calculated to evaluate the feature sensitivity through the phase point distribution of different degradation stages and then different weights are assigned to the corresponding features based on the calculated SS. Thirdly, the JADE is employed to fuse the weighted features to obtain the advanced features which can better reflect the bearing degradation process. Finally, the advanced features are input into the extreme learning machine (ELM to train the RUL prediction model. A set of experimental case studies are carried out to verify the effectiveness of the proposed method. The results show that the extracted advanced features can better reflect the degradation process compared to traditional features and could effectively predict the RUL of bearing.

  2. Composition and Structure of Massive Protoneutron Star PSR J0348+0432

    Science.gov (United States)

    Hong, B.; Jia, H. Y.; Mu, X. L.; Zhou, X.

    2015-11-01

    Considering the octet baryons in relativistic mean field (RMF) theory, the entropy per baryon is selected to be 1 or 2. We investigate the influence of the entropy per baryon for the massive protoneutron star corresponding to PSR J0348+0432. One set of coupling constants GL85 in RMF are selected to reproduce the mass of PSR J0348+0432 at zero temperature, and then extended to describe the massive protoneutron stars with the per baryon entropy S=1 or S=2. It is found that the massive protoneutron stars have more hyperons than the cold neutron stars, the temperature increases with the increase of the density from surface to interior, and the existence of hyperons leads to the decrease of the interior temperature. Entropy causes the increase of the mass of massive protoneutron star, and this effect is more obvious than that of the decreasing mass due to hyperons. The entropy per baryon brings on the increase of the radius of protoneutron star. In other words, the protoneutron star's cooling may be a contracting process.

  3. Realistic Modeling of the Pulse Profile of PSR J0737-3039A

    Science.gov (United States)

    Perera, B. B. P.; Kim, C.; McLaughlin, M. A.; Ferdman, R. D.; Kramer, M.; Stairs, I. H.; Freire, P. C. C.; Possenti, A.

    2014-05-01

    The Double Pulsar, PSR J0737-3039A/B, is a unique system in which both neutron stars have been detected as radio pulsars. As shown in Ferdman et al., there is no evidence for pulse profile evolution of the A pulsar, and the geometry of the pulsar was fit well with a double-pole circular radio beam model. Assuming a more realistic polar cap model with a vacuum retarded dipole magnetosphere configuration including special relativistic effects, we create synthesized pulse profiles for A given the best-fit geometry from the simple circular beam model. By fitting synthesized pulse profiles to those observed from pulsar A, we constrain the geometry of the radio beam, namely the half-opening angle and the emission altitude, to be ~30° and ~10 neutron star radii, respectively. Combining the observational constraints of PSR J0737-3039A/B, we are able to construct the full three-dimensional orbital geometry of the Double Pulsar. The relative angle between the spin axes of the two pulsars (ΔS) is estimated to be ~(138° ± 5°) at the current epoch and will likely remain constant until tidal interactions become important in ~85 Myr, at merger.

  4. THE TALE OF THE TWO TAILS OF THE OLDISH PSR J2055+2539

    Energy Technology Data Exchange (ETDEWEB)

    Marelli, Martino; Pizzocaro, Daniele; Luca, Andrea De; Gastaldello, Fabio; Caraveo, Patrizia [INAF—Istituto di Astrofisica Spaziale e Fisica Cosmica Milano, via E. Bassini 15, I-20133 Milano (Italy); Parkinson, Pablo Saz [Department of Physics, The University of Hong Kong, Pokfulam Road (Hong Kong)

    2016-03-01

    We analyzed a deep XMM-Newton observation of the radio-quiet γ-ray PSR J2055+2539. The spectrum of the X-ray counterpart is nonthermal, with a photon index of Γ = 2.36 ± 0.14 (1σ confidence). We detected X-ray pulsations with a pulsed fraction of 25% ± 3% and a sinusoidal shape. Taking into account considerations on the γ-ray efficiency of the pulsar and on its X-ray spectrum, we can infer a pulsar distance ranging from 450 to 750 pc. We found two different nebular features associated with PSR J2055+2539 and protruding from it. The angle between the two nebular main axes is ∼162.°8 ± 0.°7. The main, brighter feature is 12′ long and <20″ thick, characterized by an asymmetry with respect to the main axis that evolves with the distance from the pulsar, possibly forming a helical pattern. The secondary feature is 250″ × 30″. Both nebulae present an almost flat brightness profile with a sudden decrease at the end. The nebulae can be fitted by either a power-law model or a thermal bremsstrahlung model. A plausible interpretation of the brighter nebula is in terms of a collimated ballistic jet. The secondary nebula is most likely a classical synchrotron-emitting tail.

  5. The High Time Resolution Universe Pulsar Survey - XIII. PSR J1757-1854, the most accelerated binary pulsar

    Science.gov (United States)

    Cameron, A. D.; Champion, D. J.; Kramer, M.; Bailes, M.; Barr, E. D.; Bassa, C. G.; Bhandari, S.; Bhat, N. D. R.; Burgay, M.; Burke-Spolaor, S.; Eatough, R. P.; Flynn, C. M. L.; Freire, P. C. C.; Jameson, A.; Johnston, S.; Karuppusamy, R.; Keith, M. J.; Levin, L.; Lorimer, D. R.; Lyne, A. G.; McLaughlin, M. A.; Ng, C.; Petroff, E.; Possenti, A.; Ridolfi, A.; Stappers, B. W.; van Straten, W.; Tauris, T. M.; Tiburzi, C.; Wex, N.

    2018-01-01

    We report the discovery of PSR J1757-1854, a 21.5-ms pulsar in a highly-eccentric, 4.4-h orbit with a neutron star (NS) companion. PSR J1757-1854 exhibits some of the most extreme relativistic parameters of any known pulsar, including the strongest relativistic effects due to gravitational-wave (GW) damping, with a merger time of 76 Myr. Following a 1.6-yr timing campaign, we have measured five post-Keplerian (PK) parameters, yielding the two component masses (mp = 1.3384(9) M⊙ and mc = 1.3946(9) M⊙) plus three tests of general relativity (GR), which the theory passes. The larger mass of the NS companion provides important clues regarding the binary formation of PSR J1757-1854. With simulations suggesting 3-σ measurements of both the contribution of Lense-Thirring precession to the rate of change of the semi-major axis and the relativistic deformation of the orbit within ˜7 - 9 years, PSR J1757-1854 stands out as a unique laboratory for new tests of gravitational theories.

  6. Polymerase spiral reaction (PSR): a novel, visual isothermal amplification method for detection of canine parvovirus 2 genomic DNA.

    Science.gov (United States)

    Gupta, Vikas; Chakravarti, Soumendu; Chander, Vishal; Majumder, Saurabh; Bhat, Shabir Ahmad; Gupta, Vivek Kumar; Nandi, Sukdeb

    2017-07-01

    Canine parvovirus-2 (CPV-2), which is ubiquitously distributed worldwide, causes severe and often fatal gastroenteritis in dogs. Accurate, differential and rapid diagnosis of canine parvoviral enteritis remains a challenge for clinicians. A recently developed isothermal amplification technique, polymerase spiral reaction (PSR), was optimized for the first time for a viral pathogen with reference recombinant plasmid standards from different CPV-2 antigenic variants (CPV-2, CPV-2a, CPV-2b and CPV-2c) and subsequently validated using clinical samples. Addition of chromogenic substrate SYBR Green I after the completion of the reaction resulted in bright green fluorescence in positive samples, while negative samples and a no-template control remained orange. These results were further substantiated through visualization of a laddering pattern of the PSR-amplified product in an agarose gel in positive cases and the absence of this pattern in no-template control and negative samples. The PSR assay was found to be highly specific, as it did not react with other putative canine pathogens (canine adenovirus 1 and canine distemper virus). The sensitivity of the newly developed PSR technique was compared with that of conventional PCR, real-time PCR and LAMP, using a serial tenfold dilution of canine parvovirus DNA. The detection limit of PSR was found to be at the femtogram level, which is comparable with that of real-time PCR and LAMP, which are ten times more sensitive than conventional PCR. The assay was validated using 90 clinical samples, of which 54 were found positive, while only 45 samples were positive in conventional PCR. This novel assay, which is fully compliant with the 'ASSURED' concept for disease diagnosis, provides a simple, rapid, specific, sensitive and cost-effective method for diagnosis of canine parvoviral enteritis in veterinary clinics.

  7. Broadband Pulsations from PSR B1821-24: Implications for Emission Models and the Pulsar Population of M28

    Science.gov (United States)

    Johnson, T. J.; Guillemot, L.; Kerr, M.; Cognard, I.; Ray, P. S.; Wolff, M. T.; Bégin, S.; Janssen, G. H.; Romani, R. W.; Venter, C.; Grove, J. E.; Freire, P. C. C.; Wood, M.; Cheung, C. C.; Casandjian, J. M.; Stairs, I. H.; Camilo, F.; Espinoza, C. M.; Ferrara, E. C.; Harding, A. K.; Johnston, S.; Kramer, M.; Lyne, A. G.; Michelson, P. F.; Ransom, S. M.; Shannon, R.; Smith, D. A.; Stappers, B. W.; Theureau, G.; Thorsett, S. E.

    2013-12-01

    We report a 5.4σ detection of pulsed gamma rays from PSR B1821-24 in the globular cluster M28 using ~44 months of Fermi Large Area Telescope (LAT) data that have been reprocessed with improved instrument calibration constants. We constructed a phase-coherent ephemeris, with post-fit residual rms of 3 μs, using radio data spanning ~23.2 yr, enabling measurements of the multi-wavelength light-curve properties of PSR B1821-24 at the milliperiod level. We fold RXTE observations of PSR B1821-24 from 1996 to 2007 and discuss implications on the emission zones. The gamma-ray light curve consists of two peaks separated by 0.41 ± 0.02 in phase, with the first gamma-ray peak lagging behind the first radio peak by 0.05 ± 0.02 in phase, consistent with the phase of giant radio pulses. We observe significant emission in the off-peak interval of PSR B1821-24 with a best-fit LAT position inconsistent with the core of M28. We do not detect significant gamma-ray pulsations at the spin or orbital periods from any other known pulsar in M28, and we place limits on the number of energetic pulsars in the cluster. The derived gamma-ray efficiency, ~2%, is typical of other gamma-ray pulsars with comparable spin-down power, suggesting that the measured spin-down rate (2.2 × 1036 erg s-1) is not appreciably distorted by acceleration in the cluster potential. This confirms PSR B1821-24 as the second very energetic millisecond pulsar in a globular cluster and raises the question of whether these represent a separate class of objects that only form in regions of very high stellar density.

  8. Prevalence and clonal distribution of pcpA, psrP and Pilus-1 among pediatric isolates of Streptococcus pneumoniae.

    Directory of Open Access Journals (Sweden)

    Laura Selva

    Full Text Available Streptococcus pneumoniae is the leading cause of vaccine-preventable deaths globally. The objective of this study was to determine the distribution and clonal type variability of three potential vaccine antigens: Pneumococcal serine-rich repeat protein (PsrP, Pilus-1, and Pneumococcal choline binding protein A (PcpA among pneumococcal isolates from children with invasive pneumococcal disease and healthy nasopharyngeal carriers. We studied by Real-Time PCR a total of 458 invasive pneumococcal isolates and 89 nasopharyngeal pneumococcal isolates among children (total = 547 strains collected in Barcelona, Spain, from January 2004 to July 2010. pcpA, psrP and pilus-1 were detected in 92.8%, 51.7% and 14.4% of invasive isolates and in 92.1%, 48.3% and 18% of carrier isolates, respectively. Within individual serotypes the prevalence of psrP and pilus-1 was highly dependent on the clonal type. pcpA was highly prevalent in all strains with the exception of those belonging to serotype 3 (33.3% in serotype 3 isolates vs. 95.1% in other serotypes; P<.001. psrP was significantly more frequent in those serotypes that are less apt to be detected in carriage than in disease; 58.7% vs. 39.1% P<.001. Antibiotic resistance was associated with the presence of pilus-1 and showed a negative correlation with psrP. These results indicate that PcpA, and subsequently Psrp and Pilus-1 together might be good candidates to be used in a next-generation of multivalent pneumococcal protein vaccine.

  9. LMXB and IMXB Evolution: I. The Binary Radio Pulsar PSR J1614-2230

    Science.gov (United States)

    Lin, Jinrong; Rappaport, S.; Podsiadlowski, Ph.; Nelson, L.; Paxton, B.; Todorov, P.

    2011-05-01

    We have computed an extensive grid of binary evolution tracks to represent low- and intermediate-mass X-ray binaries (LMXBs and IMXBs). The grid includes 42,000 models which cover 60 initial donor masses over the range of 1-4 M sun and, for each of these, 700 initial orbital periods over the range of 10-250 hr. These results can be applied to understanding LMXBs and IMXBs: those that evolve analogously to cataclysmic variables, that form ultracompact binaries with P orb in the range of 6-50 minutes, and that lead to wide orbits with giant donors. We also investigate the relic binary recycled radio pulsars into which these systems evolve. To evolve the donor stars in this study, we utilized a newly developed stellar evolution code called "MESA" that was designed, among other things, to be able to handle very low mass and degenerate donors. This first application of the results is aimed at an understanding of the newly discovered pulsar PSR J1614-2230 which has a 1.97 M sun neutron star, P orb = 8.7 days, and a companion star of 0.5 M sun. We show that (1) this system is a cousin to the LMXB Cyg X-2; (2) for neutron stars of canonical birth mass 1.4 M sun, the initial donor stars which produce the closest relatives to PSR J1614-2230 have a mass between 3.4 and 3.8 M sun; (3) neutron stars as massive as 1.97 M sun are not easy to produce in spite of the initially high mass of the donor star, unless they were already born as relatively massive neutron stars; (4) to successfully produce a system like PSR J1614-2230 requires a minimum initial neutron-star mass of at least 1.6 ± 0.1 M sun, as well as initial donor masses and P orb of ~4.25 ± 0.10 M sun and ~49 ± 2 hr, respectively; and (5) the current companion star is largely composed of CO, but should have a surface H abundance of ~10%-15%.

  10. Scintillation measurements of the millisecond pulsar PSR J0030+0451 and pulsar space velocities

    CERN Document Server

    Nicastro, L; D'Amico, N; Lumiella, V; Johnston, S

    2001-01-01

    Scintillation observations of the nearby single millisecond pulsar (MSP) PSR J0030+0451 were carried out with the Parkes 64m radiotelescope at three different epochs in 1999. From analysis of the dynamic spectrum we obtained the amplitude of the electron density power spectrum log C_N^2 ~= -3.33$ and a scintillation velocity V_iss <~ 15 km s^-1. This result shows that the Shklovskii effect on the spin-down rate \\dot P is negligible. We also performed a correlation analysis between pulsar proper motions (V_pm) and scintillation velocities (V_iss) using updated measurements for a sample of 77 objects, 17 of which are MSPs. The full sample shows a correlation coefficient r_s ~= 80% at an extremely high significance level, while for the MSP sub-sample (excluding 2 outliers) we obtain r_s ~= 90%.

  11. Timing PSR J0453+1559: A likely asymmetric double neutron star system

    Science.gov (United States)

    Martinez, Jose; Stovall, K.; Freire, P.; Deneva, J. S.; Jenet, F.; McLaughlin, M.

    2014-01-01

    PSR J0453+1559 is a pulsar with a spin period of 45.7 ms discovered in the Arecibo All-Sky 327 MHz Drift Pulsar Survey. Subsequent observations of this source performed at the Arecibo Radio Observatory has revealed that it is in a binary system with an orbit period of 4.07 days with an eccentricity of 0.1125. The semi-major axis of the orbit is 14.5 light seconds, which implies, for a pulsar mass of 1.35 solar masses, a minimum and median companion mass of 1.0 and 1.2 solar masses respectively. This strongly suggests this is a new double neutron star (DNS) system. If confirmed, this would be the tenth DNS known in the Universe.

  12. Nature and evolution of the eclipsing millisecond binary pulsar PSR1957+20

    Energy Technology Data Exchange (ETDEWEB)

    Kluzniak, W.; Ruderman, M.; Shaham, J.; Tavani, M.

    1988-07-21

    A millisecond pulsar may be able to evaporate a very light companion by a particular component of its energetic radiation. Pulsar turn-on in the binary follows a stage of mass transfer in a very low-mass X-ray binary, dominated by an evaporative wind from the surface of a very light, at least partially degenerate companion. The wind is driven by a large MeV ..gamma..-ray flux powered by an accretion dynamo. That source of irradiation ceases when it is replaced by that from the millisecond pulsar, which has been spun up by accretion. We apply this model to the recently discovered 1.6-ms pulsar PSR1957 + 20.

  13. Evaluation of Intensive Construction Land Use in the Emerging City Based on PSR-Entropy model

    Science.gov (United States)

    Jia, Yuanyuan; Lei, Guangyu

    2018-01-01

    A comprehensive understanding of emerging city land utilization and the evaluation of intensive land use in the Emerging City will provide the comprehensive and reliable technical basis for the planning and management. It is an important node. According to the Han cheng from 2008 to 2016 years of land use, based on PSR-Entropy model of land use evaluation system, using entropy method to determine the index weight, the introduction of comprehensive index method to evaluate the degree of land use. The results show that the intensive land use comprehensive evaluation index of Han cheng increased from 2008 to 2015, but the land intensive use can not achieve the standards. The potential of further enhancing space is relatively large.

  14. PSR J2124-3358: A Unique, Isolated MSP/PWN/Bowshock

    Science.gov (United States)

    Romani, Roger

    2015-10-01

    The nearby single millisecond pulsar J2124-3358 shows a unique Halpha bow shock around a swept-back, asymmetric X-ray trail. Our ACIS exposure measures fine structure near the pulsar, discerning the spin/polar jet axis from the equatorial torus. Spectra measure the PSR cap heating and PWN synchrotron cooling. A search for moving knots in the PWN can constrain the post-shock flow speed. Comparison with our ground optical imaging and spectroscopy measures the 3-D shock geometry and is enhanced by an HST Halpha image resolving the sub-arcsecond shock apex. These permit accurate modeling of the pulsar wind momentum distribution, a measurement of the pulsar moment of inertia and a novel test of the recycling+evaporation scenario for isolated millisecond pulsars.

  15. Spectral analysis of the Double Pulsar PSR J0737-3039 with XMM-Newton

    Science.gov (United States)

    Egron, E.; Pellizzoni, A.; Iacolina, M.

    2014-07-01

    Since its discovery in 2003, the first and unique Double Pulsar system PSR J0737-3039 retains all the attention. This exciting system is composed of two neutron stars: a recycled 23 ms pulsar and a younger pulsar with a period of 2.8 s, revolving in a tight orbit in 2.4 hr. It is the only binary system in which both neutron stars have been detected as radio pulsars. The high-energy study of this system is extremely interesting to understand the physics of the magnetosphere emissions/interactions of both pulsars. We present the spectral analysis of the two XMM-Newton "Large Programs" performed in 2006 and 2011, which result in a total exposure time of about 600 ks.

  16. Limits on the mass, velocity and orbit of PSR J1933-6211

    Science.gov (United States)

    Graikou, E.; Verbiest, J. P. W.; Osłowski, S.; Champion, D. J.; Tauris, T. M.; Jankowski, F.; Kramer, M.

    2017-11-01

    We present a high-precision timing analysis of PSR J1933-6211, a millisecond pulsar with a 3.5 ms spin period and a white dwarf (WD) companion, using data from the Parkes radio telescope. Since we have accurately measured the polarization properties of this pulsar, we have applied the matrix template matching approach in which the times of arrival are measured using full polarimetric information. We achieved a weighted root-mean-square timing residuals of the timing residuals of 1.23 μs, 15.5 per cent improvement compared to the total intensity timing analysis. After studying the scintillation properties of this pulsar, we put constraints on the inclination angle of the system. Based on these measurements and on χ2 mapping we put a 2σ upper limit on the companion mass (0.44 M⊙). Since this mass limit cannot reveal the nature of the companion, we further investigate the possibility of the companion to be a He WD. Applying the orbital period-mass relation for such WDs, we conclude that the mass of a He WD companion would be about 0.26±0.01 M⊙, which combined with the measured mass function and orbital inclination limits, would lead to a light pulsar mass ≤ 1.0 M⊙. This result seems unlikely based on current neutron star formation models and we therefore conclude that PSR J1933-6211 most likely has a CO WD companion, which allows for a solution with a more massive pulsar.

  17. NUSTAR OBSERVATIONS OF THE YOUNG, ENERGETIC RADIO PULSAR PSR B1509–58

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ge; Kaspi, Victoria M. [Department of Physics, McGill University, Montreal, Quebec, H3A 2T8 (Canada); An, Hongjun [Department of Physics/KIPAC, Stanford University, Stanford, CA 94305-4060 (United States); Harrison, Fiona A.; Madsen, Kristin K. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Mail Stop 169-221, Pasadena, CA 91109 (United States)

    2016-02-01

    We report on Nuclear Spectroscopic Telescope Array (NuSTAR) hard X-ray observations of the young rotation-powered radio pulsar PSR B1509−59 in the supernova remnant MSH 15−52. We confirm the previously reported curvature in the hard X-ray spectrum, showing that a log parabolic model provides a statistically superior fit to the spectrum compared with the standard power law. The log parabolic model describes the NuSTAR data, as well as previously published γ-ray data obtained with COMPTEL and AGILE, all together spanning 3 keV through 500 MeV. Our spectral modeling allows us to constrain the peak of the broadband high energy spectrum to be at 2.6 ± 0.8 MeV, an improvement of nearly an order of magnitude in precision over previous measurements. In addition, we calculate NuSTAR spectra in 26 pulse phase bins and confirm previously reported variations of photon indices with phase. Finally, we measure the pulsed fraction of PSR B1509−58 in the hard X-ray energy band for the first time. Using the energy resolved pulsed fraction results, we estimate that the pulsar’s off-pulse emission has a photon index value between 1.26 and 1.96. Our results support a model in which the pulsar’s lack of GeV emission is due to viewing geometry, with the X-rays originating from synchrotron emission from secondary pairs in the magnetosphere.

  18. Characterising the global accretion inflow variability for PSR J1023+0038

    Science.gov (United States)

    Hernandez Santisteban, Juan

    2016-10-01

    PSR J1023+0038 is one of the first discovered transitional millisecond pulsars. These systems switch between a low-mass X-ray binary and a radio millisecond pulsar state and link these two source classes, in turn, confirming the pulsar recycling mechanism. Observation of PSR J1023+0038 and other tMSPs shown that this recycling occurs at luminosity levels usually considered as quiescent for other LMXBs. Hence, tMSPs also serve as unique avenues to test low level accretion onto neutron star surface, and interaction between accretion inflow and the pulsar magnetosphere. This low-level accretion regime has remained highly stable for the last 3.75 yr as evidenced by steady X-ray light curves characterised by 'low' and 'high' modes and rapid switches between the two. Recently, we have also seen similar moding behaviour at longer wavelengths including UV and optical. This is very intriguing as the X-ray moding originates in an inner accretion flow closer to the neutron star and constrained within the light cylinder. Whereas, UV variability is thought to emanate from colder, outer parts of the accretion disk. We request HST/NUV coverage to complement our XMM-Newton observation in order to search and characterise lags between and X-ray and UV emission. This simultaneity will allow us to probe two distinct regions of the system that seem to share a common variability. Ultimately we aim to understand what controls the accretion flow and state transitions in tMSPs.

  19. Prospects of Constraining the Dense Matter Equation of State from Timing Analysis of Pulsars in Double Neutron Star Binaries: The Cases of PSR J0737 ‒ 3039A and PSR J1757 ‒ 1854

    Directory of Open Access Journals (Sweden)

    Manjari Bagchi

    2018-02-01

    Full Text Available The Lense-Thirring effect from spinning neutron stars in double neutron star binaries contributes to the periastron advance of the orbit. This extra term involves the moment of inertia of the neutron stars. The moment of inertia, on the other hand, depends on the mass and spin of the neutron star, as well as the equation of state of the matter. If at least one member of the double neutron star binary (better the faster one is a radio pulsar, then accurate timing analysis might lead to the estimation of the contribution of the Lense-Thirring effect to the periastron advance, which will lead to the measurement of the moment of inertia of the pulsar. The combination of the knowledge on the values of the moment of inertia, the mass and the spin of the pulsar will give a new constraint on the equation of state. Pulsars in double neutron star binaries are the best for this purpose as short orbits and moderately high eccentricities make the Lense-Thirring effect substantial, whereas tidal effects are negligible (unlike pulsars with main sequence or white-dwarf binaries. The most promising pulsars are PSR J0737 − 3039A and PSR J1757 − 1854. The spin-precession of pulsars due to the misalignment between the spin and the orbital angular momentum vectors affect the contribution of the Lense-Thirring effect to the periastron advance. This effect has been explored for both PSR J0737 − 3039A and PSR J1757 − 1854, and as the misalignment angles for both of these pulsars are small, the variation in the Lense-Thirring term is not much. However, to extract the Lense-Thirring effect from the observed rate of the periastron advance, more accurate timing solutions including precise proper motion and distance measurements are essential.

  20. An ultra-compact green bio-regulator dedicated for brain cortical implant using a dynamic PSR enhancement technique.

    Science.gov (United States)

    Kok, Chiang-Liang; Siek, Liter; Gao, Fei; Zheng, Yuanjin; Lim, Wei Meng

    2012-01-01

    This article presents an ultra-compact green Bio-regulator dedicated for brain cortical implant using a dynamic PSR enhancement technique. This novel technique enabled the regulator to achieve a very high power supply rejection (PSR) of -58dB and -78dB at 1 MHz and 10MHz respectively. The Bioregulator achieves a very low quiescent current of 2µA coupled with an ultra-low power consumption of 1.8µW. This Bioregulator, simulated with Global Foundries 0.18µm CMOS process, yields a stable output voltage of 0.5V with a supply voltage ranging from 0.9-1.2V. Its distinct features, ultra-low power consumption and high PSRR at 1MHz and 10MHz, make it ideally suitable for biomedical brain cortical implant.

  1. Discovery of High-Energy Gamma-Ray Pulsations from PSR J2021+3651 with AGILE

    Science.gov (United States)

    Halpern, J. P.; Camilo, F.; Giuliani, A.; Gotthelf, E. V.; McLaughlin, M. A.; Mukherjee, R.; Pellizzoni, A.; Ransom, S. M.; Roberts, M. S. E.; Tavani, M.

    2008-11-01

    Discovered after the end of the Compton Gamma-Ray Observatory mission, the radio pulsar PSR J2021+3651 was long considered a likely counterpart of the high-energy γ-ray source 2CG 075+00 = 3EG J2021+3716 = GeV J2020+3658, but it could not be confirmed due to the lack of a contemporaneous radio pulsar ephemeris to fold the sparse, archival γ-ray photons. Here, we report the discovery of γ-ray pulsations from PSR J2021+3651 in the 100-1500 MeV range using data from the AGILE satellite gathered over 8 months, folded on a densely sampled, contemporaneous radio ephemeris obtained for this purpose at the Green Bank Telescope. The γ-ray pulse consists of two sharp peaks separated by 0.47 +/- 0.01 cycles. The single radio pulse leads the first γ-ray peak by 0.165 +/- 0.010 cycles. These properties are similar to those of other γ-ray pulsars, and the phase relationship of the peaks can be interpreted in the context of the outer-gap accelerator model for γ-ray emission. Pulse-phase-resolved images show that there is only one dominant source, AGL J2020.5+3653 = PSR J2021+3651, in the region previously containing confused sources 3EG J2021+3716 and 3EG J2016+3657.

  2. Implications of PSR J0737-3039B for the Galactic NS-NS binary merger rate

    Science.gov (United States)

    Kim, Chunglee; Perera, Benetge Bhakthi Pranama; McLaughlin, Maura A.

    2015-03-01

    The Double Pulsar (PSR J0737-3039) is the only neutron star-neutron star (NS-NS) binary in which both NSs have been detectable as radio pulsars. The Double Pulsar has been assumed to dominate the Galactic NS-NS binary merger rate R_g among all known systems, solely based on the properties of the first-born, recycled pulsar (PSR J0737-3039A, or A) with an assumption for the beaming correction factor of 6. In this work, we carefully correct observational biases for the second-born, non-recycled pulsar (PSR J0737-0737B, or B) and estimate the contribution from the Double Pulsar on R_g using constraints available from both A and B. Observational constraints from the B pulsar favour a small beaming correction factor for A (˜2), which is consistent with a bipolar model. Considering known NS-NS binaries with the best observational constraints, including both A and B, we obtain R_g=21_{-14}^{+28} Myr-1 at 95 per cent confidence from our reference model. We expect the detection rate of gravitational waves from NS-NS inspirals for the advanced ground-based gravitational-wave detectors is to be 8^{+10}_{-5} yr-1 at 95 per cent confidence. Within several years, gravitational-wave detections relevant to NS-NS inspirals will provide us useful information to improve pulsar population models.

  3. A preliminary comparative study of the electron-cloud effect for the PSR, ISIS, and the ESS

    CERN Document Server

    Furman, M A

    2003-01-01

    We present preliminary electron-cloud simulation results for the Proton Storage Ring (PSR) at LANL, ISIS at RAL, and the European Spallation Source (ESS). For each storage ring, we simulate the build-up and dissipation of the electron cloud (EC) in a representative field-free section of the vacuum chamber. For all three cases, we choose the same residual gas temperature, secondary emission yield (SEY), and secondary emission spectrum. Other variables such as proton loss rate, bunch profile, intensity and energy, residual gas pressure and chamber geometry, are set at the corresponding values for each machine. Under these assumptions, we conclude that, of the three machines, the PSR is the most severely affected by the electron cloud effect (ECE), followed by the ESS, with ISIS a distant third. We illustrate a strong sensitivity of the ECE to the longitudinal bunch profile by choosing two different shapes for the case of the PSR, and a weak sensitivity to residual gas pressure. This preliminary study does not a...

  4. On the Mass and Inclination of the PSR J2019+2425 Binary System

    CERN Document Server

    Nice, D J; Stairs, I H; Nice, David J.; Splaver, Eric M.; Stairs, Ingrid H.

    2001-01-01

    We report on nine years of timing observations of PSR J2019+2425, a millisecond pulsar in a wide 76.5 day orbit with a white dwarf. We measure a significant change over time of the projected semi-major axis of the orbit, x-dot/x=(1.3+-0.2)x10^-15 s^-1, where x=(a sin i)/c. We attribute this to the proper motion of the binary. This constrains the inclination angle to i<72 degrees, with a median likelihood value of 63 degrees. A similar limit on inclination angle arises from the lack of a detectable Shapiro delay signal. These limits on inclination angle, combined with a model of the evolution of the system, imply that the neutron star mass is at most 1.51 solar masses; the median likelihood value is 1.33 solar masses. In addition to these timing results, we present a polarization profile of this source. Fits of the linear polarization position angle to the rotating vector model indicate the magnetic axis is close to alignment with the rotation axis, alpha<30 degrees.

  5. Testing the strong equivalence principle with the triple pulsar PSR J 0337 +1715

    Science.gov (United States)

    Shao, Lijing

    2016-04-01

    Three conceptually different masses appear in equations of motion for objects under gravity, namely, the inertial mass, mI , the passive gravitational mass, mP, and the active gravitational mass, mA. It is assumed that, for any objects, mI=mP=mA in the Newtonian gravity, and mI=mP in the Einsteinian gravity, oblivious to objects' sophisticated internal structure. Empirical examination of the equivalence probes deep into gravity theories. We study the possibility of carrying out new tests based on pulsar timing of the stellar triple system, PSR J 0337 +1715 . Various machine-precision three-body simulations are performed, from which, the equivalence-violating parameters are extracted with Markov chain Monte Carlo sampling that takes full correlations into account. We show that the difference in masses could be probed to 3 ×1 0-8 , improving the current constraints from lunar laser ranging on the post-Newtonian parameters that govern violations of mP=mI and mA=mP by thousands and millions, respectively. The test of mP=mA would represent the first test of Newton's third law with compact objects.

  6. The Asymmetric Bow Shock/Pulsar Wind Nebula of PSR J2124–3358

    Science.gov (United States)

    Romani, Roger W.; Slane, Patrick; Green, Andrew W.

    2017-12-01

    We describe new measurements of the remarkable Hα/UV/X-ray bow shock and pulsar wind nebula (PWN) of the isolated millisecond pulsar (MSP) PSR J2124‑3358. Chandra X-ray Observatory imaging shows a one-sided jet structure with a softer equatorial outflow. KOALA integral field unit spectroscopy shows that non-radiative emission dominates the bow shock and that the Hα nebula is asymmetric about the pulsar velocity with an elongation into the plane of the sky. We extend analytic models of the contact discontinuity to accommodate such shapes and compare these to the data. Using Hubble Space Telescope UV detections of the pulsar and bow shock, radio timing distance, proper motion measurements, and the CXO-detected projected spin axis, we model the 3D PWN momentum flux distribution. The integrated momentum flux depends on the ionization of the ambient ISM, but for an expected ambient warm neutral medium, we infer I=2.4× {10}45 {{g}} {{cm}}2. This implies {M}{NS}=1.6{--}2.1 {M}ȯ , depending on the equation of state, which in turn suggests that the MSP gained significant mass during recycling and then lost its companion. However, this conclusion is at present tentative, since lower ionization allows ∼ 30 % lower masses, and uncertainty in the parallax allows up to 50% error.

  7. Formation of the Double Neutron Star System PSR J1930-1852

    Science.gov (United States)

    Shao, Yong; Li, Xiang-Dong

    2016-01-01

    The spin period (185 ms) and period derivative (1.8× {10}-17 {{s}} {{{s}}}-1) of the recently discovered double neutron star (DNS) system PSR J1930-1852 indicate that the pulsar was mildly recycled through the process of Roche-lobe overflow. This system has the longest orbital period (45 days) of the known DNS systems, and can be formed from a helium star-NS binary if the initial mass of the helium star was ≲ 4.0{M}⊙ ; otherwise, the helium star would never fill its Roche-lobe. At the moment of the supernova explosion, the mass of the helium star was ≲ 3.0{M}⊙ . We find that the probability distribution of the velocity kick imparted to the new-born neutron star has a maximum at about 30 {km} {{{s}}}-1 (and a tail up to 260 {km} {{{s}}}-1), indicating that this NS probably received a low kick velocity at birth.

  8. Interstellar scintillations of PSR B1919+21: space-ground interferometry

    Science.gov (United States)

    Shishov, V. I.; Smirnova, T. V.; Gwinn, C. R.; Andrianov, A. S.; Popov, M. V.; Rudnitskiy, A. G.; Soglasnov, V. A.

    2017-07-01

    We carried out observations of pulsar PSR B1919+21 at 324 MHz to study the distribution of interstellar plasma in the direction of this pulsar. We used the RadioAstron (RA) space radio telescope, together with two ground telescopes: Westerbork (WB) and Green Bank (GB). The maximum baseline projection for the space-ground interferometer was about 60 000 km. We show that interstellar scintillation of this pulsar consists of two components: diffractive scintillations from inhomogeneities in a layer of turbulent plasma at a distance z1 = 440 pc from the observer or homogeneously distributed scattering material to the pulsar; and weak scintillations from a screen located near the observer at z2 = 0.14 ± 0.05 pc. Furthermore, in the direction to the pulsar we detected a prism that deflects radiation, leading to a shift in observed source position. We show that the influence of the ionosphere can be ignored for the space-ground baseline. Analysis of the spatial coherence function for the space-ground baseline (RA-GB) yielded a scattering angle in the observer plane of θscat = 0.7 mas. An analysis of the time-frequency correlation function for weak scintillations yielded an angle of refraction in the direction to the pulsar θref, 0 = 110 ms and a distance to the prism zprism ≤ 2 pc.

  9. Multi-frequency Radio Profiles of PSR B1133+16: Radiation Location and Particle Energy

    Science.gov (United States)

    Lu, J. G.; Du, Y. J.; Hao, L. F.; Yan, Z.; Liu, Z. Y.; Lee, K. J.; Qiao, G. J.; Shang, L. H.; Wang, M.; Xu, R. X.; Yue, Y. L.; Zhi, Q. J.

    2016-01-01

    The pulse profile of PSR B1133+16 is usually regarded as a conal double structure. However, its multi-frequency profiles cannot simply be fitted with two Gaussian functions, and a third component is always needed to fit the bridge region (between two peaks). This would introduce additional, redundant parameters. In this paper, through a comparison of five fitting functions (Gaussian, von Mises, hyperbolic secant, square hyperbolic secant, and Lorentz), it is found that the square hyperbolic secant function can best reproduce the profile, yielding an improved fit. Moreover, a symmetric 2D radiation beam function, instead of a simple 1D Gaussian function, is used to fit the profile. Each profile with either well-resolved or not-so-well-resolved peaks could be fitted adequately using this beam function, and the bridge emission between the two peaks does not need to be a new component. Adopting inclination and impact angles based on polarization measurements, the opening angle ({θ }μ 0) of the radiation beam in a certain frequency band is derived from beam-function fitting. The corresponding radiation altitudes are then calculated. Based on multi-frequency profiles, we also computed the Lorentz factors of the particles and their dispersion at those locations in both the curvature-radiation and inverse-Compton-scattering models. We found that the Lorentz factors of the particles decrease rapidly as the radiation altitude increases. Besides, the radiation prefers to be generated in an annular region rather than the core region, and this needs further validation.

  10. THE SPECTRUM OF THE RECYCLED PSR J0437-4715 AND ITS WHITE DWARF COMPANION

    Energy Technology Data Exchange (ETDEWEB)

    Durant, Martin; Kargaltsev, Oleg [Department of Astronomy, University of Florida, FL 32611-2055 (United States); Pavlov, George G.; Posselt, Bettina [Department of Astronomy and Astrophysics, Pennsylvania State University, PA 16802 (United States); Kowalski, Piotr M. [Helmholtz Centre Potsdam-GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam (Germany); Van Kerkwijk, Marten H. [Department of Astronomy, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada); Kaplan, David L., E-mail: martin.durant@astro.ufl.edu [Physics Department, University of Wisconsin-Milwaukee, Milwaukee, WI 53211 (United States)

    2012-02-10

    We present extensive spectral and photometric observations of the recycled pulsar/white dwarf binary containing PSR J0437-4715, which we analyzed together with archival X-ray and gamma-ray data, to obtain the complete mid-infrared to gamma-ray spectrum. We first fit each part of the spectrum separately, and then the whole multi-wavelength spectrum. We find that the optical-infrared part of the spectrum is well fit by a cool white dwarf atmosphere model with pure hydrogen composition. The model atmosphere (T{sub eff} = 3950 {+-} 150 K, log g = 6.98 {+-} 0.15, R{sub WD} = (1.9 {+-} 0.2) Multiplication-Sign 10{sup 9} cm) fits our spectral data remarkably well for the known mass and distance (M = 0.25 {+-} 0.02 M{sub Sun }, d = 156.3 {+-} 1.3 pc), yielding the white dwarf age ({tau}{sub WD} = 6.0 {+-} 0.5 Gyr). In the UV, we find a spectral shape consistent with thermal emission from the bulk of the neutron star surface, with surface temperature between 1.25 Multiplication-Sign 10{sup 5} and 3.5 Multiplication-Sign 10{sup 5} K. The temperature of the thermal spectrum suggests that some heating mechanism operates throughout the life of the neutron star. The temperature distribution on the neutron star surface is non-uniform. In the X-rays, we confirm the presence of a high-energy tail which is consistent with a continuation of the cutoff power-law component ({Gamma} = 1.56 {+-} 0.01, E{sub cut} = 1.1 {+-} 0.2 GeV) that is seen in gamma rays and perhaps even extends to the near-UV.

  11. The NuSTAR View of the Non-Thermal Emission from PSR J0437-4715

    Science.gov (United States)

    Guillot, S.; Kaspi, V. M.; Archibald, R. F.; Bachetti, M.; Flynn, C.; Jankowski, F.; Bailes, M.; Boggs, S.; Christensen, F. E.; Craig, W. W.; hide 12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20170009872_hide">

    2016-01-01

    We present a hard X-ray Nuclear Spectroscopic Telescope Array (NuSTAR) observation of PSR J0437-4715, the nearest millisecond pulsar. The known pulsations at the apparent pulse period approximately 5.76 ms are observed with a significance of 3.7sigma, at energies up to 20 keV above which the NuSTAR background dominates. We measure a photon index gamma = 1.50 +/- 0.25(90 per cent confidence) for the power-law fit to the non-thermal emission. It had been shown that spectral models with two or three thermal components fit the XMM-Newton spectrum of PSR J0437-4715, depending on the slope of the power-law component, and the amount of absorption of soft X-rays. The new constraint on the high-energy emission provided by NuSTAR removes ambiguities regarding the thermal components of the emission below 3 keV. We performed a simultaneous spectral analysis of the XMM-Newton and NuSTAR data to confirm that three thermal components and a power law are required to fit the 0.3-20 keV emission of PSR J0437-4715. Adding a ROSAT-PSPC spectrum further confirmed this result and allowed us to better constrain the temperatures of the three thermal components. A phase resolved analysis of the NuSTAR data revealed no significant change in the photon index of the high-energy emission. This NuSTAR observation provides further impetus for future observations with the NICER mission (Neutron Star Interior Composition Explorer) whose sensitivity will provide much stricter constraints on the equation of state of nuclear matter by combining model fits to the pulsars phase-folded light curve with the pulsars well-defined mass and distance from radio timing observations.

  12. A NuSTAR Observation of the Gamma-Ray Emitting Millisecond Pulsar PSR J1723-2837

    Science.gov (United States)

    Kong, A. K. H.; Hui, C. Y.; Takata, J.; Li, K. L.; Tam, P. H. T.

    2017-04-01

    We report on the first NuSTAR observation of the gamma-ray emitting millisecond pulsar binary PSR J1723-2837. X-ray radiation up to 79 keV is clearly detected, and the simultaneous NuSTAR and Swift spectrum is well described by an absorbed power law with a photon index of ˜1.3. We also find X-ray modulations in the 3-10, 10-20, 20-79, and 3-79 keV bands at the 14.8 hr binary orbital period. All of these are entirely consistent with previous X-ray observations below 10 keV. This new hard X-ray observation of PSR J1723-2837 provides strong evidence that the X-rays are from the intrabinary shock via an interaction between the pulsar wind and the outflow from the companion star. We discuss how the NuSTAR observation constrains the physical parameters of the intrabinary shock model.

  13. The 26.3-h orbit and multiwavelength properties of the `redback' millisecond pulsar PSR J1306-40

    Science.gov (United States)

    Linares, Manuel

    2018-01-01

    We present the discovery of the variable optical and X-ray counterparts to the radio millisecond pulsar (MSP) PSR J1306-40, recently discovered by Keane et al. We find that both the optical and X-ray fluxes are modulated with the same period, which allows us to measure for the first time the orbital period Porb = 1.097 16[6] d. The optical properties are consistent with a main-sequence companion with spectral type G to mid K and, together with the X-ray luminosity (8.8 × 1031 erg s-1 in the 0.5-10 keV band, for a distance of 1.2 kpc), confirm the redback classification of this pulsar. Our results establish the binary nature of PSR J1306-40, which has the longest Porb among all known compact binary MSPs in the Galactic disc. We briefly discuss these findings in the context of irradiation and intrabinary shock emission in compact binary MSPs.

  14. SCINTILLATION ARCS IN LOW-FREQUENCY OBSERVATIONS OF THE TIMING-ARRAY MILLISECOND PULSAR PSR J0437–4715

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, N. D. R.; Ord, S. M.; Tremblay, S. E.; McSweeney, S. J.; Tingay, S. J. [International Centre for Radio Astronomy Research, Curtin University, Bentley, WA 6102 (Australia)

    2016-02-10

    Low-frequency observations of pulsars provide a powerful means for probing the microstructure in the turbulent interstellar medium (ISM). Here we report on high-resolution dynamic spectral analysis of our observations of the timing-array millisecond pulsar PSR J0437–4715 with the Murchison Widefield Array (MWA), enabled by our recently commissioned tied-array beam processing pipeline for voltage data recorded from the high time resolution mode of the MWA. A secondary spectral analysis reveals faint parabolic arcs akin to those seen in high-frequency observations of pulsars with the Green Bank and Arecibo telescopes. Data from Parkes observations at a higher frequency of 732 MHz reveal a similar parabolic feature with a curvature that scales approximately as the square of the observing wavelength (λ{sup 2}) to the MWA's frequency of 192 MHz. Our analysis suggests that scattering toward PSR J0437–4715 predominantly arises from a compact region about 115 pc from the Earth, which matches well with the expected location of the edge of the Local Bubble that envelopes the local Solar neighborhood. As well as demonstrating new and improved pulsar science capabilities of the MWA, our analysis underscores the potential of low-frequency pulsar observations for gaining valuable insights into the local ISM and for characterizing the ISM toward timing-array pulsars.

  15. A long XMM-Newton campaign on the mode-switching radio pulsar PSR B0943+10

    Science.gov (United States)

    Mereghetti, S.

    2017-10-01

    Observations obtained in the last years challenged the widespread notion that rotation-powered neutron stars are steady X-ray emitters. Besides the few pulsars showing "magnetar-like" activity, in at least one remarkable object, PSR B0943+10, significant variations, correlated to radio-mode switching have been discovered. Their study opens a new window to investigate the processes responsible for the pulsar radio and high-energy emission. An XMM-Newton Large Program, with simultaneous radio observations with LOFAR, LWA and Arecibo, allowed us to detect X-ray pulsations also during the fainter state and to better constrain the spectral and variability properties of PSR B0943+10. In both radio states the pulsed emission can be described by a thermal blackbody with temperature of a few 10^6 K and the unpulsed emission by a power-law. We discuss a scenario in which both unpulsed non-thermal emission, likely of magnetospheric origin, and pulsed thermal emission from a small polar cap (˜1500 m^2) with a strong non-dipolar field (˜10^{14} G), are present during both modes and vary in intensity in a correlated way. This is broadly consistent with the predictions of the partially screened gap model and does not necessarily imply global magnetospheric rearrangements to explain the mode switching.

  16. The NuSTAR view of the non-thermal emission from PSR J0437-4715

    DEFF Research Database (Denmark)

    Guillot, S.; Kaspi, V M; Archibald, Robert F.

    2016-01-01

    STAR background dominates. We measure a photon index Gamma = 1.50 +/- 0.25 (90 per cent confidence) for the power-law fit to the non-thermal emission. It had been shown that spectral models with two or three thermal components fit the XMM-Newton spectrum of PSR J0437-4715, depending on the slope of the power-law...... component, and the amount of absorption of soft X-rays. The new constraint on the high-energy emission provided by NuSTAR removes ambiguities regarding the thermal components of the emission below 3 keV. We performed a simultaneous spectral analysis of the XMM-Newton and NuSTAR data to confirm that three...... thermal components and a power law are required to fit the 0.3-20 keV emission of PSR J0437-4715. Adding a ROSAT-PSPC spectrum further confirmed this result and allowed us to better constrain the temperatures of the three thermal components. A phase-resolved analysis of the NuSTAR data revealed...

  17. Magnetar-like Spectral Index Flattening of the High Magnetic Field Pulsar PSR J1119-6127

    Science.gov (United States)

    Pearlman, Aaron B.; Majid, Walid A.; Horiuchi, Shinji; Kocz, Jonathon; Lippuner, Jonas; Prince, Thomas A.

    2016-12-01

    Dramatic changes in pulsed radio emission have been reported by Majid et al. (2016; arXiv:1612.02868) from the high magnetic field pulsar PSR J1119-6127 at S-band (2.3 GHz) and X-band (8.4 GHz) following the reactivation of its radio emission (Burgay et al., ATel #9366). Magnetar-like outbursts have also been observed in X-rays and gamma-rays (Kennea et al., GCN Circular #19735; Younes et al., GCN Circular #19736; Kenna et al., ATel #9274; Archibald et al. (2016); Göǧüş, et al. (2016)). We report our observations of PSR J1119-6127, spanning 1.7 hours on 03 December 2016 starting at UT 15:36:52, using the 70-m diameter Deep Space Network (DSN) radio dish (DSS-43) in Canberra, Australia. The data were recorded in filterbank search mode using 512 us time resolution. The receivers and data acquisition system are described in detail in Majid et al. (2016; arXiv:1612.02868). Pulsations were detected at S-band (2.3 GHz, 96 MHz bandwidth) and X-band (8.4 GHz, 480 MHz bandwidth) in dual circular polarization mode at a period of 0.40996974(6) s using the PRESTO pulsar search package (http://www.cv.nrao.edu/~sransom/presto). Both polarizations were combined in quadrature, and pulsed emission was seen at S/X-band with a peak signal-to-noise ratio (SNR) of 17.2/54.5. The pulse profile at S-band appears roughly singly peaked, with a smaller secondary peak near the dominant emission component. At X-band, the pulse profile shows a strong, narrow single peak. We measure a mean flux density of 0.18(4)/0.08(2) mJy at S/X-band, which represents an order of magnitude decrease at S-band and roughly a factor of 2 decrease at X-band compared to previous measurements by Majid et al. (2016; arXiv:1612.02868). Using these flux density values, we derive a spectral index -0.6(2). We also divided the X-band data into five equal 96 MHz bandwidths and detected pulsations in each subband. Mean flux densities at each subband were measured, and together with our mean flux density value at S

  18. Pulsed Gamma-Rays From PSR J2021 3651 with the Fermi Large Area Telescope

    Energy Technology Data Exchange (ETDEWEB)

    Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, Marco; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Atwood, William B.; /UC, Santa Cruz; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, Guido; /INFN, Trieste /Trieste U.; Bastieri, Denis; /INFN, Padua /Padua U.; Battelino, Milan; /Royal Inst. Tech., Stockholm; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, Ronaldo; /INFN, Pisa; Berenji, Bijan; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, Elliott D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bogaert, G.; /Ecole Polytechnique; Borgland, Anders W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Burnett, Thompson H.; /Washington U., Seattle /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Columbia U. /IASF, Milan /IASF, Milan /DAPNIA, Saclay /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /George Mason U. /Naval Research Lab, Wash., D.C. /IASF, Milan /IASF, Milan /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /LPCE, Orleans /Montpellier U. /Sonoma State U. /Royal Inst. Tech., Stockholm /Stockholm U. /ASI, Rome /NRAO, Charlottesville /Naval Research Lab, Wash., D.C. /INFN, Trieste /Pavia U. /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /UC, Santa Cruz /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /CENBG, Gradignan /CENBG, Gradignan /Manchester U. /Montpellier U. /Bari U. /INFN, Bari; /more authors..

    2011-11-30

    We report the detection of pulsed gamma-rays from the young, spin-powered radio pulsar PSR J2021+3651 using data acquired with the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope (formerly GLAST). The light curve consists of two narrow peaks of similar amplitude separated by 0.468 {+-} 0.002 in phase. The first peak lags the maximum of the 2 GHz radio pulse by 0.162 {+-} 0.004 {+-} 0.01 in phase. The integral gamma-ray photon flux above 100 MeV is (56 {+-} 3 {+-} 11) x 10{sup -8} cm{sup -2} s{sup -1}. The photon spectrum is well-described by an exponentially cut-off power law of the form dF/dE = kE{sup -{Gamma}}e{sup (-E/E{sub c})} where the energy E is expressed in GeV. The photon index is {Gamma} = 1.5 {+-} 0.1 {+-} 0.1 and the exponential cut-off is E{sub c} = 2.4 {+-} 0.3 {+-} 0.5 GeV. The first uncertainty is statistical and the second is systematic. The integral photon flux of the bridge is approximately 10% of the pulsed emission, and the upper limit on off-pulse gamma-ray emission from a putative pulsar wind nebula is < 10% of the pulsed emission at the 95% confidence level. Radio polarization measurements yield a rotation measure of RM = 524 {+-} 4 rad m{sup -2} but a poorly constrained magnetic geometry. Re-analysis of Chandra data enhanced the significance of the weak X-ray pulsations, and the first peak is roughly phase-aligned with the first gamma-ray peak. We discuss the emission region and beaming geometry based on the shape and spectrum of the gamma-ray light curve combined with radio and X-ray measurements, and the implications for the pulsar distance. Gamma-ray emission from the polar cap region seems unlikely for this pulsar.

  19. Radio Timing and Optical Photometry of the Black Widow System PSR J1518+0204C in the Globular Cluster M5

    NARCIS (Netherlands)

    Pallanca, C.; Ransom, S.M.; Ferraro, F.R.; Dalessandro, E.; Lanzoni, B.; Hessels, J.W.T.; Stairs, I.; Freire, P.C.C.

    2014-01-01

    We report on the determination of astrometric, spin, and orbital parameters for PSR J1518+0204C, a "black widow" binary millisecond pulsar in the globular cluster (GC) M5. The accurate position and orbital parameters obtained from radio timing allowed us to search for the optical companion. By using

  20. DISCOVERY OF PSR J1227−4853: A TRANSITION FROM A LOW-MASS X-RAY BINARY TO A REDBACK MILLISECOND PULSAR

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Jayanta; Bhattacharyya, Bhaswati; Stappers, Ben [Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, University of Manchester, M13 9PL (United Kingdom); Ray, Paul S.; Wolff, Michael; Wood, Kent S. [Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352 (United States); Chengalur, Jayaram N. [National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Pune 411 007 (India); Deneva, Julia [NRC Research Associate, resident at Naval Research Laboratory, Washington, DC 20375-5352 (United States); Camilo, Fernando [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Johnson, Tyrel J. [College of Science, George Mason University, Fairfax, VA 22030, USA, resident at Naval Research Laboratory, Washington, DC 20375 (United States); Hessels, Jason W. T.; Bassa, Cees G. [ASTRON, the Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA, Dwingeloo (Netherlands); Keane, Evan F. [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Mail H30, P.O. Box 218, VIC 3122 (Australia); Ferrara, Elizabeth C.; Harding, Alice K. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2015-02-10

    XSS J12270−4859 is an X-ray binary associated with the Fermi Large Area Telescope gamma-ray source 1FGL J1227.9−4852. In 2012 December, this source underwent a transition where the X-ray and optical luminosity dropped and the spectral signatures of an accretion disk disappeared. We report the discovery of a 1.69 millisecond pulsar (MSP), PSR J1227−4853, at a dispersion measure of 43.4 pc cm{sup −3} associated with this source, using the Giant Metrewave Radio Telescope (GMRT) at 607 MHz. This demonstrates that, post-transition, the system hosts an active radio MSP. This is the third system after PSR J1023+0038 and PSR J1824−2452I showing evidence of state switching between radio MSP and low-mass X-ray binary states. We report timing observations of PSR J1227−4853 with the GMRT and Parkes, which give a precise determination of the rotational and orbital parameters of the system. The companion mass measurement of 0.17–0.46 M{sub ⊙} suggests that this is a redback system. PSR J1227−4853 is eclipsed for about 40% of its orbit at 607 MHz with additional short-duration eclipses at all orbital phases. We also find that the pulsar is very energetic, with a spin-down luminosity of ∼10{sup 35} erg s{sup −1}. We report simultaneous imaging and timing observations with the GMRT, which suggests that eclipses are caused by absorption rather than dispersion smearing or scattering.

  1. A Multiwavelength Study of Nearby Millisecond Pulsar PSR J1400-1431: Improved Astrometry and an Optical Detection of Its Cool White Dwarf Companion

    Science.gov (United States)

    Swiggum, J. K.; Kaplan, D. L.; McLaughlin, M. A.; Lorimer, D. R.; Bogdanov, S.; Ray, P. S.; Lynch, R.; Gentile, P.; Rosen, R.; Heatherly, S. A.; Barlow, B. N.; Hegedus, R. J.; Vasquez Soto, A.; Clancy, P.; Kondratiev, V. I.; Stovall, K.; Istrate, A.; Penprase, B.; Bellm, E. C.

    2017-09-01

    In 2012, five high-school students involved in the Pulsar Search Collaboratory discovered the millisecond pulsar (MSP) PSR J1400-1431, and initial timing parameters were published in Rosen et al. a year later. Since then, we have obtained a phase-connected timing solution spanning five years, resolving a significant position discrepancy and measuring \\dot{P}, proper motion, parallax, and a monotonic slope in dispersion measure over time. Due to PSR J1400-1431’s proximity and significant proper motion, we use the Shklovskii effect and other priors to determine a 95% confidence interval for PSR J1400-1431’s distance, d={270}-80+130 pc. With an improved timing position, we present the first detection of the pulsar’s low-mass white dwarf (WD) companion using the Goodman Spectrograph on the 4.1 m SOAR telescope. Deeper imaging suggests that it is a cool DA-type WD with {T}{eff}=3000+/- 100 K and R/{R}⊙ =(2.19+/- 0.03)× {10}-2 (d/270 {pc}). We show a convincing association between PSR J1400-1431 and a γ-ray point source, 3FGL J1400.5-1437, but only weak (3.3σ) evidence of pulsations after folding γ-ray photons using our radio timing model. We detect an X-ray counterpart with XMM-Newton, but the measured X-ray luminosity (1×1029 erg s-1) makes PSR J1400-1431 the least X-ray luminous rotation-powered MSP detected to date. Together, our findings present a consistent picture of a nearby (d≈ 230 pc) MSP in a 9.5-day orbit around a cool ˜0.3 M ⊙ WD companion, with orbital inclination I≳ 60^\\circ .

  2. VLBI ASTROMETRY OF PSR J2222-0137: A PULSAR DISTANCE MEASURED TO 0.4% ACCURACY

    Energy Technology Data Exchange (ETDEWEB)

    Deller, A. T. [ASTRON, The Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA Dwingeloo (Netherlands); Boyles, J.; Lorimer, D. R.; McLaughlin, M. A. [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States); Kaspi, V. M. [Department of Physics, McGill University, 3600 University Street, Montreal, QC H3A 2T8 (Canada); Ransom, S. [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States); Stairs, I. H. [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Stovall, K. [Center for Advanced Radio Astronomy and Department of Physics and Astronomy, University of Texas at Brownsville, Brownsville, TX 78520 (United States)

    2013-06-20

    The binary pulsar J2222-0137 is an enigmatic system containing a partially recycled millisecond pulsar and a companion of unknown nature. While the low eccentricity of the system favors a white dwarf companion, an unusual double neutron star system is also a possibility, and optical observations will be able to distinguish between these possibilities. In order to allow the absolute luminosity (or upper limit) of the companion object to be properly calibrated, we undertook astrometric observations with the Very Long Baseline Array to constrain the system distance via a measurement of annual geometric parallax. With these observations, we measure the parallax of the PSR J2222-0137 system to be 3.742{sup +0.013}{sub -0.016} mas, yielding a distance of 267.3{sup +1.2}{sub -0.9} pc, and measure the transverse velocity to be 57.1{sup +0.3}{sub -0.2} km s{sup -1}. Fixing these parameters in the pulsar timing model made it possible to obtain a measurement of Shapiro delay and hence the system inclination, which shows that the system is nearly edge-on (sin i = 0.9985 {+-} 0.0005). Furthermore, we were able to detect the orbital motion of PSR J2222-0137 in our very long baseline interferometry (VLBI) observations and measure the longitude of ascending node {Omega}. The VLBI astrometry yields the most accurate distance obtained for a radio pulsar to date, and is furthermore the most accurate parallax for any radio source obtained at ''low'' radio frequencies (below {approx}5 GHz, where the ionosphere dominates the error budget). Using the astrometric results, we show that the companion to PSR J2222-0137 will be easily detectable in deep optical observations if it is a white dwarf. Finally, we discuss the implications of this measurement for future ultra-high-precision astrometry, in particular in support of pulsar timing arrays.

  3. A 1.05Msun Companion to PSR J2222-0137: The Coolest Known White Dwarf?

    Science.gov (United States)

    Kaplan, David

    2014-10-01

    The recycled pulsar PSR J2222-0137 is one of the closest known neutron stars, with a parallax distance of 267+/-1 pc. Using radio Shapiro delay measurements, we determine a companion mass (1.05+/-0.06 Msun) consistent with either a low-mass neutron star or a high-mass white dwarf (WD). However, the orbital eccentricity is too low to be the product of two supernovae and we are forced to conclude that the companion is a WD. And yet, despite deep optical and near-infrared searches with SOAR and the Keck telescopes we have not discovered the optical counterpart of the system and can limit its effective temperature to pulsars.

  4. Anti-correlated X-ray and Radio Variability in the Transitional Millisecond Pulsar PSR J1023+0038

    Science.gov (United States)

    Bogdanov, Slavko; Deller, Adam; Miller-Jones, James; Archibald, Anne; Hessels, Jason W. T.; Jaodand, Amruta; Patruno, Alessandro; Bassa, Cees; D'Angelo, Caroline

    2018-01-01

    The PSR J1023+0038 binary system hosts a 1.69-ms neutron star and a low-mass, main-sequence-like star. The system underwent a transformation from a rotation-powered to a low-luminosity accreting state in 2013 June, in which it has remained since. We present an unprecedented set of strictly simultaneous Chandra X-ray Observatory and Karl G. Jansky Very Large Array observations, which for the first time reveal a highly reproducible, anti-correlated variability pattern. Rapid declines in X-ray flux are always accompanied by a radio brightening with duration that closely matches the low X-ray flux mode intervals. We discuss these findings in the context of accretion and jet outflow physics and their implications for using the radio/X-ray luminosity plane to distinguish low-luminosity candidate black hole binary systems from accreting transitional millisecond pulsars.

  5. A PROPELLER MODEL FOR THE SUB-LUMINOUS STATE OF THE TRANSITIONAL MILLISECOND PULSAR PSR J1023+0038

    Energy Technology Data Exchange (ETDEWEB)

    Papitto, A.; Torres, D. F. [Institute of Space Sciences (CSIC-IEEC), Campus UAB, Carrer de Can Magrans, S/N, E-08193, Cerdanyola del Vallés, Barcelona (Spain)

    2015-07-01

    The discovery of millisecond pulsars switching between states powered either by the rotation of their magnetic field or by the accretion of matter has recently proved the tight link shared by millisecond radio pulsars and neutron stars in low-mass X-ray binaries. Transitional millisecond pulsars also show an enigmatic intermediate state in which the neutron star is surrounded by an accretion disk and emits coherent X-ray pulsations, but is sub-luminous in X-rays with respect to accreting neutron stars, and is brighter in gamma-rays than millisecond pulsars in the rotation-powered state. Here, we model the X-ray and gamma-ray emission observed from PSR J1023+0038 in such a state based on the assumptions that most of the disk in-flow is propelled away by the rapidly rotating neutron star magnetosphere, and that electrons can be accelerated to energies of a few GeV at the turbulent disk–magnetosphere boundary. We show that the synchrotron and self-synchrotron Compton emission coming from such a region, together with the hard disk emission typical of low states of accreting compact objects, is able to explain the radiation observed in the X-ray and gamma-ray bands. The average emission observed from PSR J1023+0038 is modeled by a disk in-flow with a rate of 1–3 × 10{sup −11} M{sub ⊙} yr{sup −1}, truncated at a radius ranging between 30 and 45 km, compatible with the hypothesis of a propelling magnetosphere. We compare the results we obtained with models that assume that a rotation-powered pulsar is turned on, showing how the spin-down power released in similar scenarios is hardly able to account for the magnitude of the observed emission.

  6. Discovery of the Millisecond Pulsar PSR J2043+1711 in a Fermi Source with the Nancay Radio Telescope

    Science.gov (United States)

    Guillemot, L.; Freire, P. C. C.; Cognard, I.; Johnson, T. J.; Takahashi, Y.; Kataoka, J.; Desvignes, G.; Camilo, F.; Ferrara, E. C.; Harding, A. K.; hide

    2012-01-01

    We report the discovery of the millisecond pulsar PSR J2043+1711 in a search of a Fermi Large Area Telescope (LAT) source with no known associations, with the Nancay Radio Telescope. The new pulsar, confirmed with the Green Bank Telescope, has a spin period of 2.38 ms, is relatively nearby (d approx. millisecond pulsars seen with Fermi. X-ray observations of the pulsar with Suzaku and the Swift X-ray Telescope yielded no detection. At 1.4 GHz, we observe strong flux density variations because of interstellar diffractive scintillation; however, a sharp peak can be observed at this frequency during bright scintillation states. At 327 MHz, the pulsar is detected with a much higher signal-to-noise ratio and its flux density is far more steady. However, at that frequency the Arecibo instrumentation cannot yet fully resolve the pulse profile. Despite that, our pulse time-of-arrival measurements have a post-fit residual rms of 2 micro s. This and the expected stability of this system have made PSR J2043+1711 one of the first new Fermi-selected millisecond pulsars to be added to pulsar gravitational wave timing arrays. It has also allowed a significant measurement of relativistic delays in the times of arrival of the pulses due to the curvature of space-time near the companion, but not yet with enough precision to derive useful masses for the pulsar and the companion. Nevertheless, a mass for the pulsar between 1.7 and 2.0 solar Mass can be derived if a standard millisecond pulsar formation model is assumed. In this paper, we also present a comprehensive summary of pulsar searches in Fermi LAT sources with the Nancay Radio Telescope to date.

  7. X-Ray and γ-Ray Studies of the Millisecond Pulsar and Possible X-Ray Binary/Radio Pulsar Transition Object PSR J1723-2837

    Science.gov (United States)

    Bogdanov, Slavko; Esposito, Paolo; Crawford, Fronefield, III; Possenti, Andrea; McLaughlin, Maura A.; Freire, Paulo

    2014-01-01

    We present X-ray observations of the "redback" eclipsing radio millisecond pulsar (MSP) and candidate radio pulsar/X-ray binary transition object PSR J1723-2837. The X-ray emission from the system is predominantly non-thermal and exhibits pronounced variability as a function of orbital phase, with a factor of ~2 reduction in brightness around superior conjunction. Such temporal behavior appears to be a defining characteristic of this variety of peculiar MSP binaries and is likely caused by a partial geometric occultation by the main-sequence-like companion of a shock within the binary. There is no indication of diffuse X-ray emission from a bow shock or pulsar wind nebula associated with the pulsar. We also report on a search for point source emission and γ-ray pulsations in Fermi Large Area Telescope data using a likelihood analysis and photon probability weighting. Although PSR J1723-2837 is consistent with being a γ-ray point source, due to the strong Galactic diffuse emission at its position a definitive association cannot be established. No statistically significant pulsations or modulation at the orbital period are detected. For a presumed detection, the implied γ-ray luminosity is lsim5% of its spin-down power. This indicates that PSR J1723-2837 is either one of the least efficient γ-ray producing MSPs or, if the detection is spurious, the γ-ray emission pattern is not directed toward us.

  8. X-ray and γ-ray studies of the millisecond pulsar and possible X-ray binary/radio pulsar transition object PSR J1723-2837

    Energy Technology Data Exchange (ETDEWEB)

    Bogdanov, Slavko [Columbia Astrophysics Laboratory, Columbia University, 550 West 120th Street, New York, NY 10027 (United States); Esposito, Paolo [INAF-IASF Milano, via East Bassini 15, I-20133 Milano (Italy); Crawford III, Fronefield [Department of Physics and Astronomy, Franklin and Marshall College, P.O. Box 3003, Lancaster, PA 17604 (United States); Possenti, Andrea [INAF-Osservatorio Astronomico di Cagliari, Loc. Poggio dei Pini, Strada 54, I-09012 Capoterra (Italy); McLaughlin, Maura A. [Department of Physics and Astronomy, West Virginia University, 210E Hodges Hall, Morgantown, WV 26506 (United States); Freire, Paulo, E-mail: slavko@astro.columbia.edu [Max-Planck-Institut für Radioastronomie, D-53121 Bonn (Germany)

    2014-01-20

    We present X-ray observations of the 'redback' eclipsing radio millisecond pulsar (MSP) and candidate radio pulsar/X-ray binary transition object PSR J1723-2837. The X-ray emission from the system is predominantly non-thermal and exhibits pronounced variability as a function of orbital phase, with a factor of ∼2 reduction in brightness around superior conjunction. Such temporal behavior appears to be a defining characteristic of this variety of peculiar MSP binaries and is likely caused by a partial geometric occultation by the main-sequence-like companion of a shock within the binary. There is no indication of diffuse X-ray emission from a bow shock or pulsar wind nebula associated with the pulsar. We also report on a search for point source emission and γ-ray pulsations in Fermi Large Area Telescope data using a likelihood analysis and photon probability weighting. Although PSR J1723-2837 is consistent with being a γ-ray point source, due to the strong Galactic diffuse emission at its position a definitive association cannot be established. No statistically significant pulsations or modulation at the orbital period are detected. For a presumed detection, the implied γ-ray luminosity is ≲5% of its spin-down power. This indicates that PSR J1723-2837 is either one of the least efficient γ-ray producing MSPs or, if the detection is spurious, the γ-ray emission pattern is not directed toward us.

  9. NuSTAR observations of the state transition of millisecond pulsar binary PSR J1023+0038

    Energy Technology Data Exchange (ETDEWEB)

    Tendulkar, Shriharsh P.; Bellm, Eric; Harrison, Fiona A. [California Institute of Technology, 1200 E California Blvd, MC 249-17, Pasadena, CA 91125 (United States); Yang, Chengwei; An, Hongjun; Kaspi, Victoria M. [Department of Physics, McGill University, 3600 University St, Montreal, QC H3A 2T8 (Canada); Archibald, Anne M.; Bassa, Cees; Hessels, Jason W. T.; Janssen, Gemma H. [ASTRON, The Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA, Dwingeloo (Netherlands); Bogdanov, Slavko [Columbia Astrophysics Laboratory, Columbia University, 550 West 120th Street, New York, NY 10027 (United States); Lyne, Andrew G.; Stappers, Benjamin [Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL (United Kingdom); Patruno, Alessandro [Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 RA Leiden (Netherlands); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Tomsick, John A.; Boggs, Steven E.; Craig, William W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Chakrabarty, Deepto [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 70 Vassar Street, Cambridge, MA 02139 (United States); Christensen, Finn E., E-mail: spt@astro.caltech.edu [DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); and others

    2014-08-20

    We report NuSTAR observations of the millisecond pulsar-low-mass X-ray binary (LMXB) transition system PSR J1023+0038 from 2013 June and October, before and after the formation of an accretion disk around the neutron star. Between June 10 and 12, a few days to two weeks before the radio disappearance of the pulsar, the 3-79 keV X-ray spectrum was well fit by a simple power law with a photon index of Γ=1.17{sub −0.07}{sup +0.08} (at 90% confidence) with a 3-79 keV luminosity of 7.4 ± 0.4 × 10{sup 32} erg s{sup –1}. Significant orbital modulation was observed with a modulation fraction of 36% ± 10%. During the October 19-21 observation, the spectrum is described by a softer power law (Γ=1.66{sub −0.05}{sup +0.06}) with an average luminosity of 5.8 ± 0.2 × 10{sup 33} erg s{sup –1} and a peak luminosity of ≈1.2 × 10{sup 34} erg s{sup –1} observed during a flare. No significant orbital modulation was detected. The spectral observations are consistent with previous and current multiwavelength observations and show the hard X-ray power law extending to 79 keV without a spectral break. Sharp-edged, flat-bottomed dips are observed with widths between 30 and 1000 s and ingress and egress timescales of 30-60 s. No change in hardness ratio was observed during the dips. Consecutive dip separations are log-normal in distribution with a typical separation of approximately 400 s. These dips are distinct from dipping activity observed in LMXBs. We compare and contrast these dips to observations of dips and state changes in the similar transition systems PSR J1824–2452I and XSS J1227.0–4859 and discuss possible interpretations based on the transitions in the inner disk.

  10. Discovery of the source HESS J1356-645 associated with the young and energetic PSR J1357-6429

    Science.gov (United States)

    H.E.S.S. Collaboration; Abramowski, A.; Acero, F.; Aharonian, F.; Akhperjanian, A. G.; Anton, G.; Balzer, A.; Barnacka, A.; Barres de Almeida, U.; Becherini, Y.; Becker, J.; Behera, B.; Bernlöhr, K.; Bochow, A.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Büsching, I.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P. M.; Charbonnier, A.; Chaves, R. C. G.; Cheesebrough, A.; Chounet, L.-M.; Clapson, A. C.; Coignet, G.; Cologna, G.; Conrad, J.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; O'C. Drury, L.; Dubois, F.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Egberts, K.; Eger, P.; Espigat, P.; Fallon, L.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Förster, A.; Füssling, M.; Gallant, Y. A.; Gast, H.; Gérard, L.; Gerbig, D.; Giebels, B.; Glicenstein, J. F.; Glück, B.; Goret, P.; Göring, D.; Häffner, S.; Hague, J. D.; Hampf, D.; Hauser, M.; Heinz, S.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hinton, J. A.; Hoffmann, A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; de Jager, O. C.; Jahn, C.; Jamrozy, M.; Jung, I.; Kastendieck, M. A.; Katarzynski, K.; Katz, U.; Kaufmann, S.; Keogh, D.; Khangulyan, D.; Khélifi, B.; Klochkov, D.; Kluzniak, W.; Kneiske, T.; Komin, Nu.; Kosack, K.; Kossakowski, R.; Laffon, H.; Lamanna, G.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Masbou, J.; Maurin, D.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Medina, M. C.; Méhault, J.; Moderski, R.; Moulin, E.; Naumann, C. L.; Naumann-Godo, M.; de Naurois, M.; Nedbal, D.; Nekrassov, D.; Nguyen, N.; Nicholas, B.; Niemiec, J.; Nolan, S. J.; Ohm, S.; de Ona Wilhelmi, E.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Paz Arribas, M.; Pedaletti, G.; Pelletier, G.; Petrucci, P.-O.; Pita, S.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raue, M.; Rayner, S. M.; Reimer, A.; Reimer, O.; Renaud, M.; de Los Reyes, R.; Rieger, F.; Ripken, J.; Rob, L.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Ruppel, J.; Sahakian, V.; Sanchez, D.; Santangelo, A.; Schlickeiser, R.; Schöck, F. M.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sikora, M.; Skilton, J. L.; Sol, H.; Spengler, G.; Stawarz, L.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tavernet, J.-P.; Terrier, R.; Tluczykont, M.; Valerius, K.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Vialle, J. P.; Viana, A.; Vincent, P.; Völk, H. J.; Volpe, F.; Vorobiov, S.; Vorster, M.; Wagner, S. J.; Ward, M.; White, R.; Wierzcholska, A.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.

    2011-09-01

    Context. Several newly discovered very-high-energy (VHE; E > 100 GeV) γ-ray sources in the Galaxy are thought to be associated with energetic pulsars. Among them, middle-aged (≳ 104 yr) systems exhibit large centre-filled VHE nebulae, offset from the pulsar position, which result from the complex relationship between the pulsar wind and the surrounding medium, and reflect the past evolution of the pulsar. Aims: Imaging Atmospheric Cherenkov Telescopes (IACTs) have been successful in revealing extended emission from these sources in the VHE regime. Together with radio and X-ray observations, this observational window allows one to probe the energetics and magnetic field inside these large-scale nebulae. Methods: H.E.S.S., with its large field of view, angular resolution of ≲0.1° and unprecedented sensitivity, has been used to discover a large population of such VHE sources. In this paper, the H.E.S.S. data from the continuation of the Galactic Plane Survey (- 80° law dN/dE ∝ E-Γ with photon index Γ = 2.2 ± 0.2stat ± 0.2sys. The inspection of archival radio images at three frequencies and the analysis of X-ray data from ROSAT/PSPC and XMM-Newton/MOS reveal the presence of faint non-thermal diffuse emission coincident with HESS J1356-645. Conclusions: HESS J1356-645 is most likely associated with the young and energetic pulsar PSR J1357-6429 (d = 2.4 kpc, τc = 7.3 kyr and Ė = 3.1 × 1036 erg s-1), located at a projected distance of ~5 pc from the centroid of the VHE emission. HESS J1356-645 and its radio and X-ray counterparts would thus represent the nebula resulting from the past history of the PSR J1357-6429 wind. In a simple one-zone model,

  11. A Feed-Forward Loop Consisting of the Response Regulator RpaB and the Small RNA PsrR1 Controls Light Acclimation of Photosystem I Gene Expression in the Cyanobacterium Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Kadowaki, Taro; Nagayama, Ryuta; Georg, Jens; Nishiyama, Yoshitaka; Wilde, Annegret; Hess, Wolfgang R; Hihara, Yukako

    2016-04-01

    Since cyanobacteria need to decrease PSI content to avoid absorption of excess light energy, down-regulation of PSI gene expression is one of the key characteristics of the high-light (HL) acclimation response. The transcriptional regulator RpaB and the small RNA PsrR1 (photosynthesis regulatory RNA1) have been suggested to be the two most critical factors for this response in Synechocystis sp. PCC 6803. In this study, we found that the HLR1 DNA-binding motif, the recognition sequence for RpaB, is highly conserved in the core promoter region of the psrR1 gene among cyanobacterial species. Gel mobility shift assay revealed that RpaB binds to the HLR1 sequence of psrR1 in vitro. RNA gel blot analysis together with chromatin affinity purification (ChAP) analysis suggested that PSI genes are activated and the psrR1 gene is repressed by the binding of RpaB under low-light (LL) conditions. A decrease in DNA binding affinity of RpaB occurs within 5 min after the shift from LL to HL conditions, leading to the prompt decrease in PSI promoter activity together with derepression of psrR1 gene expression. Accumulating PsrR1 molecules then prevent translation from pre-existing PSI transcripts. By this dual repression at transcriptional and post-transcriptional levels, rapid and strict down-regulation of PSI expression under HL is secured. Our findings suggest that RpaB and PsrR1 constitute a feed-forward loop for the regulation of PSI gene expression to achieve a rapid acclimation response to the damaging HL conditions. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  12. Spectroscopic Analysis of the Companion to the Binary MSP PSR J1740-5340 in NGC 6397

    Science.gov (United States)

    Sabbi, E.; Ferraro, F. R.; Gratton, R.; Bragaglia, A.; Possenti, A.; D'Amico, N.

    2005-10-01

    By means of high-resolution spectra, we have measured radial velocities of the companion (hereafter COM J1740-5340) to the eclipsing millisecond pulsar PSR J1740-5340 in the galactic globular cluster NGC 6397. The radial velocity curve enables us to derive the mass ratio (MPSR/MCOM = 5.85 +/- 0.13). The derived abundances are fully compatible with those of normal unperturbed stars in NGC 6397, with the exception of a few elements. The lack of C, in particular, suggests that the star has been peeled down to regions where incomplete CNO burning occurs, supporting a scenario where the companion is a turn-off star which has lost most of its mass. A detailed analysis of the Hα lines reveals that optically thin hydrogen gas resided outside the Roche lobe of COM J1740-5340. The line morphology suggests the presence of a steam of material going from the companion toward the neutron star; this material never reachs the neutron star surface, being driven back by the pulsar radiation, far beyond COM J1740-5340. The unexpected detection of strong He I absorption lines implies the existence of regions at T > 10,000 K, which are significantly warmer than the rest of the star, and reveals the existence of a region on the companion surface, heated by the millisecond pulsar flux.

  13. High-precision timing of millisecond pulsars. II - Astrometry, orbital evolution, and eclipses of PSR 1957 + 20

    Science.gov (United States)

    Ryba, M. F.; Taylor, J. H.

    1991-01-01

    Pulse time-of-arrival measurements have been acquired for PSR 1957 + 20 on 61 days over a 2.7 yr interval, including the times of 44 eclipse disappearance or reappearance events. The timing data provide a reliable measurement of the pulsar's proper motion, 29 +/- 3 mas/yr, at position angle 216 +/- 6 deg; this direction is in excellent agreement with that suggested by the cometlike shape of a surrounding optical emission nebula. The rate of change of the orbital period has been measured: a surprisingly large (-3.9 +/- 0.9) x 10 exp -11, implying that significant orbital evolution must take place on a time scale of 30 Myr. Finally, the present observations extend the eclipse measurements to higher frequencies and provide better statistics for these highly variable phenomena. The eclipse data are used to compute a column-density profile of free electrons in the outer parts of the eclipsing region, and thereby provide an important glimpse into the material being ablated from the companion star.

  14. X-Rays from the Nearby Solitary Millisecond Pulsar PSR J0030+0451 - the Final ROSAT Observations

    CERN Document Server

    Becker, W; Bäcker, A N; Lommen, D; Becker, Werner; Tr"umper, Joachim; Backer, Andrea N.Lommen & Donald C.

    2000-01-01

    We report on X-ray observations of the solitary 4.8 ms pulsar PSR J0030+0451. The pulsar was one of the last targets observed in DEC-98 by the ROSAT PSPC. X-ray pulses are detected on a $4.5\\sigma$ level and make the source the $11^{th}$ millisecond pulsar detected in the X-ray domain. The pulsed fraction is found to be $69\\pm18%$. The X-ray pulse profile is characterized by two narrow peaks which match the gross pulse profile observed at 1.4 GHz. Assuming a Crab-like spectrum the X-ray flux is in the range $f_x= 2-3\\times 10^{-13}$ erg s$^{-1}$ cm$^{-2} $ ($0.1-2.4$ keV), implying an X-ray efficiency of $L_x/\\dot{E}\\sim 0.5-5 \\times 10^{-3} (d/0.23 {kpc})^2$.

  15. Possible Evidence for Pulsed X-Ray Emission from the Outer Gap in PSR B1937+21

    Science.gov (United States)

    Wang, H. G.; Xu, R. X.; Qiao, G. J.

    2002-10-01

    The fastest millisecond pulsar PSR B1937+21 presents an interpulse separated from the main pulse by nearly 180° at radio frequencies. Recently, the ASCA observations detected pulsed X-ray emission from this pulsar. Only a single narrow X-ray pulse is observed, which is coincident with the radio interpulse in phase. We investigate the possible origin of the pulsed X-rays from the polar cap (PC) accelerators or the outer gap (OG) accelerators in the frame of a PC model and an OG model, respectively, by assuming a dipolar magnetic field structure and the same radio emission pattern from its poles for the pulsar. The OG model can naturally explain the main observational facts. For the PC model, the coincidence between the X-ray pulse and the radio interpulse cannot be reproduced in the assumed case. However, when considering possible deviation from our assumption, the PC model may still be valid for this pulsar in some cases.

  16. Observational constraints on the radio and γ-ray emission regions of PSR B1055-52

    Science.gov (United States)

    Wang, H. G.; Qiao, G. J.; Xu, R. X.; Liu, Y.

    2006-03-01

    Observational constraints on the radio and γ-ray emission regions of PSR B1055-52 seen through our line of sight are presented by analysing the position angle curves of radio linear polarization and fitting the observed pulse widths of radio and γ-ray pulses and the phase offsets between them. Aberration, retardation and magnetic field sweep back effects that can cause additional phase offset between the emissions from different locations are taken into account. The following conclusions are obtained. (i) The radio main pulse and γ-ray pulses are emitted from the same pole, while the radio interpulse is emitted from the opposite pole. (ii) The interpulse emission region locates on the open field lines much closer to the magnetic axis than those of the main pulse, and the emission altitudes are higher than those of the main pulse. (iii) At each pole, there are probably two groups of field lines where radio emission is generated, of which the outer one consists of open field lines near (or including) the last open field lines and the inner one consists of open field lines from very near the magnetic pole to approximately the midway between the magnetic axis and the last open field lines. (iv) The γ-ray pulse comes from inner open field lines rather than from the last open field lines, and the emission altitudes are beyond the null charge surface.

  17. X-Ray Analysis of the Proper Motion and Pulsar Wind Nebula for PSR J1741-2054

    Science.gov (United States)

    Auchettl, Katie; Slane, Patrick; Romani, Roger W.; Posselt, Bettina; Pavlov, George G.; Kargaltsev, Oleg; Ng, C-Y.; Temim, Tea; Weisskopf, Martin C.; Bykov, Andrei; hide

    2015-01-01

    We obtained six observations of PSR J1741-2054 using the Chandra ACIS-S detector totaling approx.300 ks. By registering this new epoch of observations to an archival observation taken 3.2 yr earlier using X-ray point sources in the field of view, we have measured the pulsar proper motion at micron = 109 +/- 10 mas yr(exp. -1) in a direction consistent with the symmetry axis of the observed H(alpha) nebula. We investigated the inferred past trajectory of the pulsar but find no compelling association with OB associations in which the progenitor may have originated. We confirm previous measurements of the pulsar spectrum as an absorbed power law with photon index gamma = 2.68 +/- 0.04, plus a blackbody with an emission radius of (4.5(+3.2/-2.5))d(0.38) km, for a DM-estimated distance of 0.38d(0.38) kpc and a temperature of 61.7 +/- 3.0 eV. Emission from the compact nebula is well described by an absorbed power law model with a photon index of gamma = 1.67 +/- 0.06, while the diffuse emission seen as a trail extending northeast of the pulsar shows no evidence of synchrotron cooling. We also applied image deconvolution techniques to search for small-scale structures in the immediate vicinity of the pulsar, but found no conclusive evidence for such structures.

  18. The TeV {gamma}-ray binary PSR B1259-63. Observations with the high energy stereoscopic system in the years 2005-2007

    Energy Technology Data Exchange (ETDEWEB)

    Kerschhaggl, Matthias

    2010-04-06

    PSR B1259-63/SS2883 is a binary system where a 48 ms pulsar orbits a massive Be star with a period of 3.4 years. The system exhibits variable, non-thermal radiation around periastron on the highly eccentric orbit (e=0.87) visible from radio to very high energies (VHE; E>100 GeV). When being detected in TeV {gamma}-rays with the High Energy Stereoscopic System (H.E.S.S.) in 2004 it became known as the first variable galactic VHE source. This thesis presents VHE data from PSR B1259-63 as taken during the years 2005, 2006 and before as well as shortly after the 2007 periastron passage. These data extend the knowledge of the lightcurve of this object to all phases of the binary orbit. The lightcurve constrains physical mechanisms present in this TeV source. Observations of VHE {gamma}-rays with the H.E.S.S. telescope array using the Imaging Atmospheric Cherenkov Technique were performed. The H.E.S.S. instrument features an angular resolution of < 0.1 and an energy resolution of < 20%. Gamma-ray events in an energy range of 0.5-70 TeV were recorded. From these data, energy spectra and lightcurve with a monthly time sampling were extracted. VHE {gamma}-ray emission from PSRB1259-63 was detected with an overall significance of 9.5 standard deviations using 55 h of exposure, obtained from April to August 2007. The monthly flux of -rays during the observation period was measured, yielding VHE lightcurve data for the early pre-periastron phase of the system for the first time. No spectral variability was found on timescales of months. The spectrum is described by a power law with a photon index of {gamma}=2.8{+-}0.2{sub stat}{+-}0.2{sub sys} and flux normalisation {phi}{sub 0}=(1.1{+-}0.1{sub stat}{+-}0.2{sub sys}) x 10{sup -12} TeV{sup -1}cm{sup -2}s{sup -1}. PSR B1259-63 was also monitored in 2005 and 2006, far from periastron passage, comprising 8.9 h and 7.5 h of exposure, respectively. No significant excess of {gamma}-rays is seen in those observations. PSR B1259-63 has

  19. NuSTAR OBSERVATIONS AND BROADBAND SPECTRAL ENERGY DISTRIBUTION MODELING OF THE MILLISECOND PULSAR BINARY PSR J1023+0038

    Energy Technology Data Exchange (ETDEWEB)

    Li, K. L.; Kong, A. K. H.; Tam, P. H. T.; Jin, Ruolan [Institute of Astronomy and Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Takata, J.; Cheng, K. S. [Department of Physics, University of Hong Kong, Pokfulam Road (Hong Kong); Hui, C. Y., E-mail: lilirayhk@gmail.com, E-mail: akong@phys.nthu.edu.tw, E-mail: takata@hku.hk [Department of Astronomy and Space Science, Chungnam National University, Daejeon (Korea, Republic of)

    2014-12-20

    We report the first hard X-ray (3-79 keV) observations of the millisecond pulsar (MSP) binary PSR J1023+0038 using NuSTAR. This system has been shown transiting between a low-mass X-ray binary (LMXB) state and a rotation-powered MSP state. The NuSTAR observations were taken in both LMXB state and rotation-powered state. The source is clearly seen in both states up to ∼79 keV. During the LMXB state, the 3-79 keV flux is about a factor of 10 higher than in the rotation-powered state. The hard X-rays show clear orbital modulation during the X-ray faint rotation-powered state but the X-ray orbital period is not detected in the X-ray bright LMXB state. In addition, the X-ray spectrum changes from a flat power-law spectrum during the rotation-powered state to a steeper power-law spectrum in the LMXB state. We suggest that the hard X-rays are due to the intrabinary shock from the interaction between the pulsar wind and the injected material from the low-mass companion star. During the rotation-powered MSP state, the X-ray orbital modulation is due to Doppler boosting of the shocked pulsar wind. At the LMXB state, the evaporating matter of the accretion disk due to the gamma-ray irradiation from the pulsar stops almost all the pulsar wind, resulting in the disappearance of the X-ray orbital modulation.

  20. A BROADBAND RADIO STUDY OF THE AVERAGE PROFILE AND GIANT PULSES FROM PSR B1821-24A

    Energy Technology Data Exchange (ETDEWEB)

    Bilous, A. V. [Department of Astrophysics/IMAPP, Radboud University Nijmegen, P.O. Box 9010, 6500 GL Nijmegen (Netherlands); Pennucci, T. T. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Demorest, P. [National Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801 (United States); Ransom, S. M., E-mail: a.bilous@science.ru.nl [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States)

    2015-04-20

    We present the results of a wideband (720–2400 MHz) study of PSR B1821–24A (J1824–2452A, M28A), an energetic millisecond pulsar (MSP) visible in radio, X-rays and γ-rays. In radio, the pulsar has a complex average profile that spans ≳85% of the spin period and exhibits strong evolution with observing frequency. For the first time we measure phase-resolved polarization properties and spectral indices of radio emission throughout almost all of the on-pulse window. We synthesize our findings with high-energy information to compare M28A to other known γ-ray MSPs and to speculate that M28A’s radio emission originates in multiple regions within its magnetosphere (i.e., both in the slot or outer gaps near the light cylinder and at lower altitudes above the polar cap). M28A is one of a handful of pulsars that are known to emit giant radio pulses (GRPs)—short, bright radio pulses of unknown nature. We report a drop in the linear polarization of the average profile in both windows of GRP generation and also a “W”-shaped absorption feature (resembling a double notch), partly overlapping with one of the GRP windows. The GRPs themselves have broadband spectra consisting of multiple patches with Δν/ν ∼ 0.07. Although our time resolution was not sufficient to resolve the GRP structure on the μs scale, we argue that GRPs from this pulsar most closely resemble the GRPs from the main pulse of the Crab pulsar, which consist of a series of narrowband nanoshots.

  1. Analysis of single pulse radio flux measurements of PSR B1133+16 at 4.85 and 8.35 GHz

    Science.gov (United States)

    Krzeszowski, K.; Maron, O.; Słowikowska, A.; Dyks, J.; Jessner, A.

    2014-05-01

    We show the results of microsecond resolution radio data analysis focused on flux measurements of single pulses of PSR B1133+16. The data were recorded at 4.85 and 8.35 GHz with 0.5- and 1.1-GHz bandwidth, respectively, using Radio Telescope Effelsberg (Max-Planck-Institut für Radioastronomie). The most important conclusion of the analysis is that the strongest single pulse emission at 4.85 and 8.35 GHz contributes almost exclusively to the trailing part of the leading component of the pulsar mean profile, whereas studies at lower frequencies report that the contribution is spread almost uniformly, covering all phases of the pulsar mean profile. We also estimate the radio emission heights to be around 1-2 per cent of the light-cylinder radius, which is in agreement with previous studies. Additionally, these observations allowed us to add two more measurements of the flux density to the PSR B1133+16 broad-band radio spectrum, covering frequencies from 16.7 MHz up to 32 GHz. We fit two different models to the spectrum: a broken power law and a spectrum based on the flicker-noise model, which represents the spectrum in a simpler, but similarly accurate, way.

  2. LytR-CpsA-Psr proteins in Staphylococcus aureus display partial functional redundancy and the deletion of all three severely impairs septum placement and cell separation.

    Science.gov (United States)

    Over, Benjamin; Heusser, Ronald; McCallum, Nadine; Schulthess, Bettina; Kupferschmied, Peter; Gaiani, Jessica M; Sifri, Costi D; Berger-Bächi, Brigitte; Stutzmann Meier, Patricia

    2011-07-01

    Staphylococcus aureus contains three members of the LytR-CpsA-Psr (LCP) family of membrane proteins: MsrR, SA0908 and SA2103. The characterization of single-, double- and triple-deletion mutants revealed distinct phenotypes for each of the three proteins. MsrR was involved in cell separation and septum formation and influenced β-lactam resistance; SA0908 protected cells from autolysis; and SA2103, although displaying no apparent phenotype by itself, enhanced the properties of msrR and sa0908 mutants when deleted. The deletion of sa0908 and sa2103 also further attenuated the virulence of msrR mutants in a nematode-killing assay. The severely defective growth phenotype of the triple mutant revealed that LytR-CpsA-Psr proteins are essential for optimal cell division in S. aureus. Growth could be rescued to varying degrees by any one of the three proteins, indicating some functional redundancy within members of this protein family. However, differing phenotypic characteristics of all single and double mutants and complemented triple mutants indicated that each protein played a distinct role(s) and contributed differently to phenotypes influencing cell separation, autolysis, cell surface properties and virulence. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  3. Distribution of interstellar plasma in the direction of PSR B0525+21 from data obtained on a ground-space interferometer

    Science.gov (United States)

    Andrianov, A. S.; Smirnova, T. V.; Shishov, V. I.; Gwinn, C.; Popov, M. V.

    2017-06-01

    Observations on the RadioAstron ground-space interferometer with the participation of the Green Bank and Arecibo ground telescopes at 1668 MHz have enabled studies of the characteristics of the interstellar plasma in the direction of the pulsar PSR B0525+21. The maximum projected baseline for the ground-space interferometer was 233 600 km. The scintillations in these observations were strong, and the spectrum of inhomogeneties in the interstellar plasma was a power law with index n = 3.74, corresponding to a Kolmogorov spectrum. A new method for estimating the size of the scattering disk was applied to estimate the scattering angle (scattering disk radius) in the direction toward PSR B0525+21, θ scat = 0.028 ± 0.002 milliarcsecond. The scattering in this direction occurs in a plasma layer located at a distance of 0.1 Z from the pulsar, where Z is the distance from the pulsar to the observer. For the adopted distance Z = 1.6 kpc, the screen is located at a distance of 1.44 kpc from the observer.

  4. Review of PSR framework and development of a DPSIR model to assess greenhouse effect in Taiwan.

    Science.gov (United States)

    Huang, Hui-Fen; Kuo, Jeff; Lo, Shang-Lien

    2011-06-01

    In dealing with the complex issues of greenhouse gas (GHG) emission and climate change mitigation, many interrelated factors such as cost, level of technology development, supply and demand of energy, structure of industry, and expenditures on research and development exist. Using indicators to monitor environmental impacts and evaluate the efficacies of policies and regulations has been practiced for a long time, and it can serve as a useful tool for decision making and for comparison between different countries. Although numerous indicators have been developed for relevant subjects, integrated approaches that consider individual changes, dynamic interaction, and multi-dimensions of indicators are scarce. This paper aimed to develop a Driving Force-Pressure-State-Impact-Response (DPSIR) framework to assess the problems. This DPSIR model is mainly related to energy consumption, environmental impacts, and policy responses. The objectives of the paper were: (1) conduct a literature review on the indicators that have been used in GHG-related studies; (2) develop a DPSIR model that incorporates GHG-related indicators and evaluate their relationships using a cause-effect chain of GHG emission; and (3) develop a calculative method that can be used to explain the dynamic correlation among the interdependent indicators. Taiwan is a significant source of global GHG emissions. A case study, using the developed framework and Taiwan's actual data of the past two decades, was conducted. The results indicate that regulatory strategies for pollution control are inadequate in terms of ensuring environmental quality, and the nature does not have the capability to revert the impacts from the existing level of pollution.

  5. The Remarkable Synchrotron Nebula Associated with PSR J1015-5719

    Science.gov (United States)

    Ng, Chi Yung; Bandiera, Rino; Hunstead, Richard; Johnston, Simon

    2017-08-01

    We report the discovery of a synchrotron nebula G283.1-0.59 associated with the young and energetic pulsar J1015-5719. Radio observations using the Molonglo Observatory Synthesis Telescope (MOST) and the Australia Telescope Compact Array (ATCA) at 36, 16, 6, and 3 cm reveal a complex morphology for the source. The pulsar is embedded in the "head" of the nebula with fan-shaped diffuse emission. This is connected to a circular bubble structure of 20" radius and followed by a collimated tail extending over 1'. Polarization measurements show a highly ordered magnetic field in the nebula. The intrinsic B-field wraps around the edge of the head and shows an azimuthal configuration near the pulsar, then switches direction quasi-periodically near the bubble and in the tail. Together with the flat radio spectrum observed, we suggest that this system is most plausibly a pulsar wind nebula (PWN), with the head as a bow shock that has a low Mach number and the bubble as a shell expanding in a dense environment, possibly due to flow instabilities. In addition, the bubble could act as a magnetic bottle trapping the relativistic particles. A comparison with other bow-shock PWNe with higher Mach numbers shows similar structure and B-field geometry, implying that pulsar velocity may not be the most critical factor in determining the properties of these systems.ATCA is part of the Australia Telescope National Facility which is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO. MOST is operated by The University of Sydney with support from the Australian Research Council and the Science Foundation for Physics within the University of Sydney. This work is supported by an ECS grant under HKU 709713P.

  6. Fermi LAT Detection of an Intense GeV Gamma-ray Flare From the Be-Pulsar Binary PSR B1259-63 at 70 Days After Periastron

    Science.gov (United States)

    Johnson, T. J.; Wood, K. S.; Ray, P. S.; Kerr, M. T.; Cheung, C. C.

    2017-12-01

    We have detected an intense flare in > 100 MeV gamma rays from the Be-pulsar binary system PSR B1259-63, using data from the Large Area Telescope (LAT), one of the two instruments on board the Fermi Gamma-ray Space Telescope.

  7. Research

    African Journals Online (AJOL)

    ebutamanya

    2015-03-02

    Mar 2, 2015 ... Using a critical leadership theory framework, we conducted a qualitative ... or basic science research career (Socio-Behavioral Research, ... AITRP was to develop HIV research leaders at the University of ..... Wellcome-Trust.

  8. FORMATION OF THE GALACTIC MILLISECOND PULSAR TRIPLE SYSTEM PSR J0337+1715—A NEUTRON STAR WITH TWO ORBITING WHITE DWARFS

    Energy Technology Data Exchange (ETDEWEB)

    Tauris, T. M. [Argelander-Institut für Astronomie, Universität Bonn, Auf dem Hügel 71, D-53121 Bonn (Germany); Van den Heuvel, E. P. J., E-mail: tauris@astro.uni-bonn.de [Astronomical Institute Anton Pannekoek, University of Amsterdam, P.O. Box 94249, 1090 GE Amsterdam (Netherlands)

    2014-01-20

    The millisecond pulsar in a triple system (PSR J0337+1715, recently discovered by Ransom et al.) is an unusual neutron star with two orbiting white dwarfs. The existence of such a system in the Galactic field poses new challenges to stellar astrophysics for understanding evolution, interactions, and mass transfer in close multiple stellar systems. In addition, this system provides the first precise confirmation for a very wide-orbit system of the white dwarf mass-orbital period relation. Here, we present a self-consistent, semi-analytical solution to the formation of PSR J0337+1715. Our model constrains the peculiar velocity of the system to be less than 160 km s{sup –1} and brings novel insight to, for example, common envelope evolution in a triple system, for which we find evidence for in-spiral of both outer stars. Finally, we briefly discuss our scenario in relation to alternative models.

  9. Different twins in the millisecond pulsar recycling scenario: Optical polarimetry of PSR J1023+0038 and XSS J12270-4859

    Science.gov (United States)

    Baglio, M. C.; D'Avanzo, P.; Campana, S.; Coti Zelati, F.; Covino, S.; Russell, D. M.

    2016-06-01

    We present the first optical polarimetric study of the two transitional pulsars PSR J1023+0038 and XSS J12270-4859. This work is focused on the search for intrinsically linearly polarised optical emission from the two systems. To this aim, we carried out multiband optical (BVRi) and near-infrared (NIR; JHK) photo-polarimetric observations of the two systems using the ESO New Technology Telescope (NTT) at La Silla (Chile), equipped with the EFOSC2 and the SOFI instruments. The system XSS J12270-4859 was observed during its radio-pulsar state; we did not detect a significant degree of polarisation in any of the bands, with 3σ upper limits, for example, of 1.4% in the R-band. We built the NIR-optical averaged spectral energy distribution (SED) of the system, which could be described well by an irradiated black body with radius R∗ = 0.33 ± 0.03 R⊙ and albedo η = 0.32 ± 0.05, without the need for further components. Thus, we excluded the visible presence of an extended accretion disc and/or of relativistic jets. The case was different for PSR J1023+0038, which was in its accretion phase during our campaign. We measured a linear polarisation of 1.09 ± 0.27% and 0.90 ± 0.17% in the V and R bands, respectively. The phase-resolved polarimetric curve of the source in the R band reveals a hint of a sinusoidal modulation at the source 4.75 h orbital period, peaked at the same orbital phase as the light curve. The measured optical polarisation of PSR J1023+0038 could, in principle, be interpreted as electron scattering with free electrons, which can be found in the accretion disc of the system or even in the hot corona that sorrounds the disc itself, or as synchrotron emission from a jet of relativistic particles or an outflow. However, the NIR-optical SED of the system built from our dataset did not suggest the presence of a jet. We conclude that the optical linear polarisation observed for PSR J1023+0038 is possibly due to Thomson scattering with electrons in the

  10. Mid-UV Studies of the Transitional Millisecond Pulsars XSS J12270-4859 and PSR J1023+0038 During Their Radio Pulsar States

    Science.gov (United States)

    Sandoval, L. E. Rivera; Hernández Santisteban, J. V.; Degenaar, N.; Wijnands, R.; Knigge, C.; Miller, J. M.; Reynolds, M.; Altamirano, D.; van den Berg, M.; Hill, A.

    2018-02-01

    We report mid-UV (MUV) observations taken with HST/WFC3, Swift/UVOT and GALEX/NUV of the transitional millisecond pulsars XSS J12270-4859 and PSR J1023+0038 during their radio pulsar states. Both systems were detected in our images and showed MUV variability. At similar orbital phases, the MUV luminosities of both pulsars are comparable. This suggests that the emission processes involved in both objects are similar. We estimated limits on the mass ratio, companion's temperature, inclination, and distance to XSS J12270-4859 by using a Markov Chain Monte Carlo algorithm to fit published folded optical light curves. Using the resulting parameters, we modeled MUV light curves in our HST filters. The resulting models failed to fit our MUV observations. Fixing the mass ratio of XSS J12270-4859 to the value reported in other studies, we obtained a distance of ˜3.2 kpc. This is larger than the one derived from dispersion measure (˜1.4 kpc). Assuming a uniform prior for the mass ratio, the distance is similar to that from radio measurements. However, it requires an undermassive companion (˜0.01M⊙). We conclude that a direct heating model alone can not fully explain the observations in optical and MUV. Therefore, an additional radiation source is needed. The source could be an intrabinary shock which contributes to the MUV flux and likely to the optical one as well. During the radio pulsar state, the MUV orbital variations of PSR J1023+0038 detected with GALEX, suggests the presence of an asymmetric intrabinary shock.

  11. A histopathologic evaluation of the Plasma Skin Regeneration System (PSR) versus a standard carbon dioxide resurfacing laser in an animal model.

    Science.gov (United States)

    Fitzpatrick, R; Bernstein, E; Iyer, S; Brown, D; Andrews, P; Penny, K

    2008-02-01

    A variety of high energy, pulsed, and scanned carbon dioxide lasers are available to perform cutaneous resurfacing. Rhytec has developed a device for skin regeneration that utilizes energy delivered via a burst of nitrogen plasma. This study was undertaken to benchmark the energy outputs of the plasma skin regeneration device as compared to an ultra-short pulsed carbon dioxide laser (the control device). The two systems were compared for time to complete healing, and the healing response post-treatment. Three Yucatan mini-pigs were utilized for this study. Following anesthesia, five experimental sites were marked along the skin atop the psoas muscle on each side of the spine. Treatment was applied using either the plasma skin regeneration system or the carbon dioxide laser, with one site remaining untreated as a control. Biopsies were taken from all treatment sites 0, 2, 7, 14, 30, and 60 days following treatment and processed to hematoxylin-eosin staining. Histopathologic examination was performed by observers blinded as to the treatment conditions. Skin treated with the plasma skin regeneration device showed a wider range of tissue effects across the energy settings used as compared to the laser treatment. All treatment sites had clinically regenerated epidermis by 7 days after treatment, with active cellular response below the D/E junction noted at the day 30 time-point at energies ranging from 2 to 4 J. The Rhytec PSR system provides an attractive alternative to standard CO2 laser with good remodeling of tissue architecture. Epidermis regenerated after PSR treatment shows a smoother surface profile than adjacent untreated tissue.

  12. Research

    African Journals Online (AJOL)

    The research was aimed at improving the current practice of radiation safety training of radiographers and was, therefore, considered action research.[18] The processes of action and research was integrated because the teaching activities and assessment were developed after the Delphi survey and aligned with the ...

  13. Research

    African Journals Online (AJOL)

    of the Western Cape (UWC), Cape Town, South Africa the students are exposed to research in various modules where they are trained in epidemiology, research methods and literature appraisal. In addition, they personally conduct a research project, performing relevant statistical analyses. The relevant modules for.

  14. Research

    African Journals Online (AJOL)

    ebutamanya

    2015-05-13

    May 13, 2015 ... Systems (SEEDS)-INDEPTH Network Accra, Ghana, 3KEMRI/Wellcome Trust Research Programme, The Centre of Geographical Medicine Research-. Coast, Kilifi, Kenya, 4Population Health Sciences/Research Support Unit, Faculty of Health Sciences, Aga Khan University- East Africa, Nairobi,. Kenya ...

  15. Research.

    Science.gov (United States)

    Raudenbush, Stephen

    In May of 1999, the American Academy of Arts and Sciences hosted a conference on ways to improve the scientific quality of educational research. In medicine, thanks to work 40 years ago by 2 researchers, Howard Hyatt and Frederick Mosteller, the commitment of medical professionals to base their diagnoses and prescriptions on clinical trials in…

  16. Research

    African Journals Online (AJOL)

    Results. Three emergent themes were identified from the results of this study: a lack of standardised guidelines for nurse academics to effectively supervise postgraduate research; the pressure that nurse academics experience regarding postgraduate research supervision; other demanding roles of an academic, such as a ...

  17. Research

    African Journals Online (AJOL)

    first time, on the findings of a research study on the implementation of field trips in a management module in the BPharm curriculum and to conclude whether this intervention changed pharmacy students' perception of the module. Method. A mixed-method sequential exploratory research design was followed,.

  18. Research

    African Journals Online (AJOL)

    abp

    2016-04-29

    Apr 29, 2016 ... Anonymity of respondents was assured by concealing their identity and research data was kept confidential for research purposes only. The study was conducted by full adherence of the ..... Samwel K. Misoi, Richard K. Rotich, Anthony K. Mwanthi and George. M. Mwita for their moderation throughout the ...

  19. Research

    African Journals Online (AJOL)

    An interview guide approach was implemented in face-to-face in-depth interviews ... Dependability of the data collected was ensured through an audit trail. The main researcher and supervisor served as peer .... [16] A growing body of research reports that students with high academic resilience and self-efficacy are more ...

  20. Research

    African Journals Online (AJOL)

    Research. 108 September 2017, Vol. 9, No. 3 AJHPE. Methods. This is a qualitative descriptive study that explored nursing students' experiences. ..... Challenges and lessons learned. Clin. Simulation Nursing 2013;9(5):e157-e162. https://doi.org/10.1016/j.ecns.2011.11.011. 12. Creswell JW. Research Design. 4th ed.

  1. Research

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    abp

    2015-09-09

    Sep 9, 2015 ... Traumatology, Umraniye Research and Education Hospital, 34899 ... This is an Open Access article distributed under the terms of the Creative Commons .... and major complication such as pain, seroma, dog ears, widening of.

  2. Research

    African Journals Online (AJOL)

    that should promote basic capabilities and functionings as well as academic achievement. ... for development and wellbeing on an educational, personal and social level.[2] ... Research indicates that academic stressors, living circumstances, working conditions and where students undertake leisure activities affect.

  3. Research

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    ebutamanya

    2015-08-28

    Aug 28, 2015 ... Ethiopia, 2Bahir Dar Regional Health Research Laboratory Center, Department ... of Public Health, 4Institute of Medical Microbiology and Epidemiology of Infectious .... active ingredient x 10,000 dilution rate of product): 0.1%.

  4. Research

    African Journals Online (AJOL)

    raoul

    2011-11-14

    Nov 14, 2011 ... Background: For many women in Kenya, their husbands act as ... and researching whether men are translating this knowledge into action ..... older participants, and participants with multiparous wives, reflecting personal.

  5. Research

    African Journals Online (AJOL)

    abp

    2013-11-06

    Nov 6, 2013 ... 1University of Botswana, Gaborone, Botswana, 2Research Institute for Humanity and Nature, Kyoto, Japan, 3School of Public Health, University of the Western Cape, Bellville, South Africa, 4Japan Overseas Christian Medical Co-operative Services, C/o Roman Catholic Archdiocese of Tabora,. Private Bag ...

  6. Research

    African Journals Online (AJOL)

    212-218. [http:// dx.doi.org/10.1207/s15430421tip4104_2]. 22. Pepper C. 'There's a lot of learning going on but NOT much teaching!': Student perceptions of problem-based learning in science. Higher Education Research & Development 2010 ...

  7. Research

    African Journals Online (AJOL)

    2017-03-24

    Mar 24, 2017 ... 26 March 2017, Vol. 9, No. 1 AJHPE. Research were distributed among varying levels of advancement within the EM training programme (Table 1). Responses to the qualitative section of the survey were categorised into major themes, providing insight into the overall acceptability of small-group education.

  8. Research

    African Journals Online (AJOL)

    Research. December 2017, Vol. 9, No. 4 AJHPE 189. Community-based education (CBE) is a learning approach that enables students to acquire skills by means of ... of CBE include early contact with the community, improved teamwork of ... A descriptive cross-sectional survey was conducted at the University of Zimbabwe.

  9. Research

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    ebutamanya

    2015-08-06

    Aug 6, 2015 ... permanent contraceptive methods and women's education (AOR=1.72, 95%CI = 1.02 - 3.05), women's occupation (AOR = 2.01, 95% CI = 1.11 -. 3.58), number of live .... NGO's and presence of different Medias in the area. The result of this .... Social and Behavior Change Communication. Research Brief.

  10. Research

    African Journals Online (AJOL)

    abp

    2016-01-27

    Jan 27, 2016 ... (SD) age of the male subjects was 38.4(14.9) years and that of the females was 40.8(13.9) years (p> 0.05). The overall ... Published in partnership with the African Field Epidemiology Network (AFENET). (www.afenet.net) ... Trained research assistants administered questionnaires and obtained the ...

  11. Research

    African Journals Online (AJOL)

    YouTube, TED and other podcast websites. Other researchers have also documented their procedures. Corl et al.[5] describe the basic process of producing a podcast, and Jham et al.[6] list a number of universities actively doing podcasts. Besides the lecture podcasts, we have also captured numerous clinical.

  12. Research

    African Journals Online (AJOL)

    abp

    2015-01-05

    Jan 5, 2015 ... Methods: this was a descriptive cross-sectional study conducted in Talensi district in the Upper East Region of Ghana. Systematic random ..... 14. Saunders MNK, Lewis P and Thornhill A. Research methods for business students. FT Prentice Hall. (2003); 3rd Edition. Harlow. Google Scholar. 15. Allen K ...

  13. Research

    African Journals Online (AJOL)

    raoul

    2012-02-17

    Feb 17, 2012 ... Organizational Behaviour and Human Decision Processes. 2000; 50: 79-211. 13. Montano DE and Kasprzyk D. The Theory of Reasoned Action and the Theory of Planned Behaviour Glanz, K Lewis, FM Rimer, BK eds. Health Behaviour and Health Education, Theory, Research and Practice: Jossy Bass ...

  14. Research

    African Journals Online (AJOL)

    abp

    2016-04-15

    Apr 15, 2016 ... 1National Reference Center in Neonatology and Nutrition, Children's Hospital, University Hospital, Rabat, Morocco, 2Research Team on Health and ... This is an Open Access article distributed under the terms of the Creative Commons .... were globally performed in older mothers with a mean age of 31.5.

  15. Research

    African Journals Online (AJOL)

    the standard of future practice. Therefore, it is imperative for healthcare educators to understand the issues students face in their everyday fieldwork practice and equip them to deal with these ethical issues. Objectives. The objective of this research was to determine the issues that students face in their fieldwork practice and ...

  16. Research

    African Journals Online (AJOL)

    ebutamanya

    2015-01-15

    Jan 15, 2015 ... diagnosed cases with FNAB as either benign or malignant when correlated with histology were 95% and 100% respectively. Conclusion: FNAB is ... foot). This study was conducted in compliance with the guidelines of the Helsinki declaration on biomedical research in human subjects. Confidentiality of the ...

  17. Research

    African Journals Online (AJOL)

    ebutamanya

    2015-12-16

    Dec 16, 2015 ... of this policy, there is need to monitor the implementation progress, identify the challenges and mitigate them and determine better strategies for implementation .... Ethical Considerations: ethical Clearance to carry out the research ... 10% of the respondents reported that the government was doing enough ...

  18. Research

    African Journals Online (AJOL)

    ebutamanya

    Received: 03/12/2014 - Accepted: 15/01/2015 - Published: 13/03/2015. Abstract. Introduction: ... Studies have called on the need for further additional research to establish how supportive supervision in health systems should be best carried out effectively .... male to female medical practitioners in Kenya stood at 60% and.

  19. Research

    African Journals Online (AJOL)

    abp

    2015-06-09

    Jun 9, 2015 ... The authors sincerely thank the staff of Clinical Research Education,. Networking and Consultancy (CRENC), Douala Cameroon for statistical analysis, data interpretation and assistance in drafting the manuscript. Tables and figures. Table 1: Characteristics (socio-demographic and clinical) of women.

  20. Research

    African Journals Online (AJOL)

    abp

    2013-10-29

    Oct 29, 2013 ... mosquito-borne diseases, however, limited research has been documented on infections with dengue. This study ... presence of antibodies against dengue virus 2 (denv-2) in a cross-section of febrile out-patients visiting three selected hospitals to assess the level .... treatments prescribed was recorded.

  1. Research

    African Journals Online (AJOL)

    abp

    2017-05-10

    May 10, 2017 ... (Approval number B/874), Joint Research Ethics Committee, Health Studies Office and the Manicaland Directorate Institutional Review Board. Written informed .... parasites, but without any features of severe malaria between. September ..... T-lymphocytes, impairment of antibody formulation and atrophy of.

  2. Research

    African Journals Online (AJOL)

    abp

    2016-04-14

    Apr 14, 2016 ... Methods: A mixed methods study was conducted using both .... Methods. Study design: A mixed method cross-sectional design using both quantitative and qualitative research methods as described by. Hanson et al [33] was employed. ..... Musheke M, Ntalasha H, Gari S, McKenzie O, Bond V, Martin-.

  3. Research

    African Journals Online (AJOL)

    raoul

    2011-08-25

    Aug 25, 2011 ... euthanasia were also queried. Data was analyzed using Epidata, SPSS 16.0 and Microsoft Excel. Results: Thirty-eight (97.4%) of thirty-nine institutions reported using animals for education and/or research. Thirty (76.9%) institutions reported using analgesics or anesthetics on a regular basis. Thirteen ...

  4. Research

    African Journals Online (AJOL)

    abp

    2016-04-28

    Apr 28, 2016 ... Published in partnership with the African Field Epidemiology Network (AFENET). (www.afenet.net). Research .... interstitial compartment and may lead to distal tubular damage, some with attendant nephrogenic diabetes ..... Model Summary R=0.861, R2=0.742, Standard error of estimate=0.046, p<0.001.

  5. Research

    African Journals Online (AJOL)

    ebutamanya

    2015-01-30

    Jan 30, 2015 ... Published in partnership with the African Field Epidemiology Network (AFENET). (www.afenet.net). Research. Open Access ... compartment syndrome [4,5]. According to the literature, incidence ... fed into a multiple regression model to assess the odds ratio. Results. Between March 2012 and March 31, ...

  6. Research

    African Journals Online (AJOL)

    1 AJHPE 43. Research. Patient-centredness requires pharmacists to view their patients as individuals with unique experiences.[1] Each patient in their social context responds uniquely to ... To determine the prevalence of the 16 different Myers-Briggs Type Indicator®(MBTI®) communication styles, and compare them with.

  7. Research

    African Journals Online (AJOL)

    The mixed-methods approach was selected as the most appropriate research design for data collection and analysis. The use of multiple data collection instruments and sources provided a broader perspective and deeper understanding of the core concepts of the evaluation from the perspective of multiple sources. Results ...

  8. Research

    African Journals Online (AJOL)

    During Phase I of the mixed-methods research design, data were collected by means of a nominal group technique. Nominal group discussions were held with the class leaders to identify possible themes/ topics to describe the perceptions of health sciences students with regard to. CBE and SL. These themes and topics ...

  9. Research

    African Journals Online (AJOL)

    than student assessment.[12,13] One needs to ... Cut scores for students' assessments have always been arbitrarily determined in many institutions. Some institutions ..... Research. December 2017, Vol. 9, No. 4 AJHPE 175 correct answers to the judges before the scoring exercise, an observation that arguably creates bias.

  10. Research

    African Journals Online (AJOL)

    2 AJHPE. Research. The Ugandan Ministry of Health (MOH) identified lack of leadership and management skills, rather than lack of resources, as the main reason for poor healthcare delivery in the country.[1] Healthcare professionals, as an integral component of Uganda's healthcare system, receive a high level of training ...

  11. Research

    African Journals Online (AJOL)

    raoul

    2012-01-11

    Jan 11, 2012 ... 1MPH Programme, Department of Community Medicine, University of Zimbabwe, Zimbabwe, 2Department of Epidemiology and Disease Control,. Ministry ... Pan African Medical Journal. 2012; 11: ..... Mufuta Tshimanga: Had oversight of all the stages of the research and critically reviewed the final draft for.

  12. Research

    African Journals Online (AJOL)

    Research. Clinical teaching is a technique used in the education of nurses. It involves the exposure of students to authentic clinical environments and guiding them to attain specific requirements applicable in that particular environment.[1] The clinical environment is a platform for the application of knowledge and skills that ...

  13. Research

    African Journals Online (AJOL)

    This model involves the allocation of nursing students to a qualified professional nurse who, in the course of ... who qualified in general nursing and midwifery at a rural hospital in. Lesotho. Eight professional .... research that explored the experiences and perceptions of healthcare workers in clinical environments about the ...

  14. Research

    African Journals Online (AJOL)

    ebutamanya

    2016-04-20

    Apr 20, 2016 ... were reviewed using an agreed data collection pro forma considering 3 main outcomes; i) quantity of complete entries, ii) percentage completeness of individual sections, iii) documentation ... impossible to evaluate the reliability of this data and the utility of these books as a tool for research. A clinical audit ...

  15. Research

    African Journals Online (AJOL)

    abp

    2017-05-01

    May 1, 2017 ... p=0.019) respectively. Conclusion: Patient's perceived attitude and stigma towards treatment observers contribute to non-adherence on TB treatment. For improved local TB control, ... Published in partnership with the African Field Epidemiology Network (AFENET). (www.afenet.net). Research. Open Access ...

  16. Research

    African Journals Online (AJOL)

    tions as their reality.[14]. Research context. At Stellenbosch University (SU), Cape Town,. SA, final-year physiotherapy students each spend. 6 weeks at a community site learning to integrate and apply the principles of PHC and community- based rehabilitation. Approximately 5 - 10 clients are seen in their homes per week.

  17. Research

    African Journals Online (AJOL)

    acquire public health, clinical, and/or research skills, usually through applied learning in a community setting,[1] with goals that include: creating knowledge, skills and attitudes among students to ensure they are capable of providing high- quality health services to local, underserved communities, often in rural areas.

  18. Research

    African Journals Online (AJOL)

    Communities provide the reality of social and health challenges and therefore provide the platform for learning and exploring their authentic challenges.[1] Community-university partnerships are thus intended to bring together academic researchers and communities, share power, establish trust, foster co-learning, enhance ...

  19. Research

    African Journals Online (AJOL)

    good) and the weaknesses (things that need to be improved) of students' performance, and possible things that can be improved after the mini-CEX assessment. The existence of this reflection on experience indicates that there has been a deep learning process.[12,14] We suggest that future research should elaborate on ...

  20. Research

    African Journals Online (AJOL)

    abp

    2016-07-13

    Jul 13, 2016 ... definitions of invasive fungal disease of the European Organization for Research and Treatment of Cancer/Mycosis Study Group. (EORTC/MSG) [15]. In total, 91 patients were identified that among them, 16 were excluded because of discharge against medical advice. The cases that were diagnosed on an ...

  1. Research

    African Journals Online (AJOL)

    abp

    2016-05-13

    May 13, 2016 ... based study that enrolled breast cancer patients from catchment area of an oncology service hospital in Nigeria between 2007 and 2013. ... ISSN: 1937- 8688 (www.panafrican-med-journal.com). Published in partnership with the African Field Epidemiology Network (AFENET). (www.afenet.net). Research.

  2. Research

    African Journals Online (AJOL)

    raoul

    2012-02-17

    Feb 17, 2012 ... Psychology and Health. 2001; 16(4): 423-441. 15. Creswell J: Research Design. Qualitative & Quantitative Approaches. 1994; Sage Publications. 16. Biomedical communication. Avalable at http://www.bmc.med.utoronto.ca/bmc/index.php. Accessed 1 February 2012. 17. Glaser BG. Emergence vs. Forcing.

  3. Research

    African Journals Online (AJOL)

    2017-03-02

    Mar 2, 2017 ... In summary, this study explored the perceptions and experiences of nurse educators' use of HFS in teaching, as its acceptability by educators as a teaching strategy is important for effective use. Methods. Research design. A descriptive, qualitative case study design was utilised to explore nursing.

  4. Research

    African Journals Online (AJOL)

    2014-05-02

    May 2, 2014 ... the quality of graduates and providing them with the necessary skills and competencies to ... However, most of the aforementioned evaluation studies focus on the training process .... except two areas, i.e. X-ray image interpretation and research skills. All 72 respondents ... Ultrasound. Mammography.

  5. Research

    African Journals Online (AJOL)

    2016-05-26

    May 26, 2016 ... [5] At the nucleus of systems thinking is the ability 'to balance the interests of several conflicting interests with an ultimate focus on the benefit of the institution as a whole'. ... The longitudinal series of interviews formed part of the first author's action research design,[8] aimed at her professional development.

  6. Research

    African Journals Online (AJOL)

    abp

    2014-03-13

    Mar 13, 2014 ... Published in partnership with the African Field Epidemiology Network (AFENET). (www.afenet.net). Research ..... Artisan. 361(15.1). Civil servant. 348(14.6). Professional/Business Executive. 138(5.8). Mode of acquisition of HIV. Heterosexual Contact. 1876(78.5). Blood and Blood product. 129(5.4). MTCT.

  7. Radio timing and optical photometry of the black widow system PSR J1518+0204C in the globular cluster M5

    Energy Technology Data Exchange (ETDEWEB)

    Pallanca, C.; Ferraro, F. R.; Dalessandro, E.; Lanzoni, B. [Dipartimento di Fisica e Astronomia, Università di Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy); Ransom, S. M. [National Radio Astronomy Observatory (NRAO), 520 Edgemont Road, Charlottesville, VA 22901 (United States); Hessels, J. W. T. [ASTRON, the Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA Dwingeloo (Netherlands); Stairs, I. [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T1Z1 (Canada); Freire, P. C. C. [Max-Planck-Institute für Radioastronomie, D-53121 Bonn (Germany)

    2014-11-01

    We report on the determination of astrometric, spin, and orbital parameters for PSR J1518+0204C, a 'black widow' binary millisecond pulsar in the globular cluster (GC) M5. The accurate position and orbital parameters obtained from radio timing allowed us to search for the optical companion. By using WFC3/Hubble Space Telescope images, we identified a very faint variable star (m{sub F390W} ≳ 24.8, m{sub F606W} ≳ 24.3, m{sub F814W} ≳ 23.1) located at only 0.''25 from the pulsar's timing position. Due to its strong variability, this star is visible only in a subsample of images. However, the light curve obtained folding the available data with the orbital parameters of the pulsar shows a maximum at the pulsar inferior conjunction and a possible minimum at the pulsar superior conjunction. Furthermore, the shape of the optical modulation indicates a heating process possibly due to the pulsar wind. This is the first identification of an optical companion to a black widow pulsar in the dense stellar environment of a GC.

  8. Radio Timing and Optical Photometry of the Black Widow System PSR J1953+1846A in the Globular Cluster M71

    Science.gov (United States)

    Cadelano, M.; Pallanca, C.; Ferraro, F. R.; Stairs, I.; Ransom, S. M.; Dalessandro, E.; Lanzoni, B.; Hessels, J. W. T.; Freire, P. C. C.

    2015-07-01

    We report on the determination of the astrometric, spin, and orbital parameters for PSR J1953+1846 A, a “black widow” binary millisecond pulsar in the globular cluster M71. By using the accurate position and orbital parameters obtained from radio timing, we identified the optical companion in Advanced Camera for Surveys/Hubble Space Telescope images. It turns out to be a faint ({m}{{F}606{{W}}}≳ 24, {m}{{F}814{{W}}}≳ 23) and variable star located at only ˜0.″06 from the pulsar timing position. The light curve shows a maximum at the pulsar inferior conjunction and a minimum at the pulsar superior conjunction, thus confirming the association with the system. The shape of the optical modulation suggests that the companion star is heated, likely by the pulsar wind. The comparison with the X-ray light curve possibly suggests the presence of an intra-binary shock due to the interaction between the pulsar wind and the material released by the companion. This is the second identification (after COM-M5C) of an optical companion to a black widow pulsar in a globular cluster. Interestingly, the two companions show a similar light curve and share the same position in the color-magnitude diagram. Based on observations collected with the NASA/ESA HST (Prop. 12932), obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS5-26555.

  9. Radio Timing and Optical Photometry of the Black Widow System PSR J1518+0204C in the Globular Cluster M5

    Science.gov (United States)

    Pallanca, C.; Ransom, S. M.; Ferraro, F. R.; Dalessandro, E.; Lanzoni, B.; Hessels, J. W. T.; Stairs, I.; Freire, P. C. C.

    2014-11-01

    We report on the determination of astrometric, spin, and orbital parameters for PSR J1518+0204C, a "black widow" binary millisecond pulsar in the globular cluster (GC) M5. The accurate position and orbital parameters obtained from radio timing allowed us to search for the optical companion. By using WFC3/Hubble Space Telescope images, we identified a very faint variable star (mF390W >~ 24.8, mF606W >~ 24.3, mF814W >~ 23.1) located at only 0.''25 from the pulsar's timing position. Due to its strong variability, this star is visible only in a subsample of images. However, the light curve obtained folding the available data with the orbital parameters of the pulsar shows a maximum at the pulsar inferior conjunction and a possible minimum at the pulsar superior conjunction. Furthermore, the shape of the optical modulation indicates a heating process possibly due to the pulsar wind. This is the first identification of an optical companion to a black widow pulsar in the dense stellar environment of a GC. Based on observations collected with the NASA/ESA HST (Prop. 19835), obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS5-26555.

  10. GMRT DISCOVERY OF PSR J1544+4937: AN ECLIPSING BLACK-WIDOW PULSAR IDENTIFIED WITH A FERMI-LAT SOURCE

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharyya, B.; Roy, J.; Gupta, Y. [National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Pune 411 007 (India); Ray, P. S.; Wolff, M. T.; Wood, K. S. [Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352 (United States); Bhattacharya, D. [Inter-University Centre for Astronomy and Astrophysics, Pune 411 007 (India); Romani, R. W.; Den Hartog, P. R.; Kerr, M.; Michelson, P. F. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Ransom, S. M. [National Radio Astronomy Observatory (NRAO), Charlottesville, VA 22903 (United States); Ferrara, E. C.; Harding, A. K. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Camilo, F. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Cognard, I. [Laboratoire de Physique et Chimie de l' Environnement, LPCE UMR 6115 CNRS, F-45071 Orleans Cedex 02 (France); Johnston, S.; Keith, M. [CSIRO Astronomy and Space Science, Australia Telescope National Facility, Epping, NSW 1710 (Australia); Saz Parkinson, P. M. [Santa Cruz Institute for Particle Physics, Department of Physics and Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); Wood, D. L. [Praxis Inc., Alexandria, VA 22303 (United States)

    2013-08-10

    Using the Giant Metrewave Radio Telescope, we performed deep observations to search for radio pulsations in the directions of unidentified Fermi-Large Area Telescope {gamma}-ray sources. We report the discovery of an eclipsing black-widow millisecond pulsar, PSR J1544+4937, identified with the uncataloged {gamma}-ray source FERMI J1544.2+4941. This 2.16 ms pulsar is in a 2.9 hr compact circular orbit with a very low mass companion (M{sub c} > 0.017M{sub Sun }). At 322 MHz this pulsar is found to be eclipsing for 13% of its orbit, whereas at 607 MHz the pulsar is detected throughout the low-frequency eclipse phase. Variations in the eclipse ingress phase are observed, indicating a clumpy and variable eclipsing medium. Moreover, additional short-duration absorption events are observed around the eclipse boundaries. Using the radio timing ephemeris we were able to detect {gamma}-ray pulsations from this pulsar, confirming it as the source powering the {gamma}-ray emission.

  11. PSR J2021+4026 IN THE GAMMA CYGNI REGION: THE FIRST VARIABLE γ-RAY PULSAR SEEN BY THE Fermi LAT

    Energy Technology Data Exchange (ETDEWEB)

    Allafort, A.; Bottacini, E.; Cameron, R. A. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Baldini, L. [Università di Pisa and Istituto Nazionale di Fisica Nucleare, Sezione di Pisa I-56127 Pisa (Italy); Ballet, J.; Chaves, R.C.G. [Laboratoire AIM, CEA-IRFU/CNRS/Université Paris Diderot, Service d' Astrophysique, CEA Saclay, F-91191 Gif sur Yvette (France); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Baring, M. G. [Rice University, Department of Physics and Astronomy, MS-108, P. O. Box 1892, Houston, TX 77251 (United States); Bastieri, D.; Buson, S. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Bellazzini, R.; Bregeon, J. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Bonamente, E.; Cecchi, C. [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy); Brandt, T. J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Bruel, P. [Laboratoire Leprince-Ringuet, École polytechnique, CNRS/IN2P3, F-91128 Palaiseau (France); Buehler, R. [Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen (Germany); Caliandro, G. A. [Institut de Ciències de l' Espai (IEEE-CSIC), Campus UAB, E-08193 Barcelona (Spain); Caraveo, P. A. [INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica, I-20133 Milano (Italy); Chekhtman, A., E-mail: ltibaldo@slac.stanford.edu, E-mail: massimiliano.razzano@pi.infn.it [Center for Earth Observing and Space Research, College of Science, George Mason University, Fairfax, VA 22030, resident at Naval Research Laboratory, Washington, DC 20375 (United States); and others

    2013-11-01

    Long-term monitoring of PSR J2021+4026 in the heart of the Cygnus region with the Fermi Large Area Telescope unveiled a sudden decrease in flux above 100 MeV over a timescale shorter than a week. The 'jump' was near MJD 55850 (2011 October 16), with the flux decreasing from (8.33 ± 0.08) × 10{sup –10} erg cm{sup –2} s{sup –1} to (6.86 ± 0.13) × 10{sup –10} erg cm{sup –2} s{sup –1}. Simultaneously, the frequency spindown rate increased from (7.8 ± 0.1) × 10{sup –13} Hz s{sup –1} to (8.1 ± 0.1) × 10{sup –13} Hz s{sup –1}. Significant (>5σ) changes in the pulse profile and marginal (<3σ) changes in the emission spectrum occurred at the same time. There is also evidence for a small, steady flux increase over the 3 yr preceding MJD 55850. This is the first observation at γ-ray energies of mode changes and intermittent behavior, observed at radio wavelengths for other pulsars. We argue that the change in pulsed γ-ray emission is due to a change in emission beaming and we speculate that it is precipitated by a shift in the magnetic field structure, leading to a change of either effective magnetic inclination or effective current.

  12. PSR J2021+4026 in the Gamma Cygni Region: The First Variable Gamma-Ray Pulsar Seen by the Fermi LAT

    Science.gov (United States)

    Allafort, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Bellazzini, R.; Bonamente, E.; Bottacini, E.; Brandt, T. J.; hide

    2013-01-01

    Long-term monitoring of PSR J2021+4026 in the heart of the Cygnus region with the Fermi Large Area Telescope unveiled a sudden decrease in flux above 100 MeV over a timescale shorter than a week. The "jump" was near MJD 55850 (2011 October 16), with the flux decreasing from (8.33 plus or minus 0.08)×10(exp -10) erg cm(exp -2) s(exp -1) to (6.86 plus or minus 0.13)× 10 (exp -1)0 erg cm (exp -2) s(exp -1). Simultaneously, the frequency spindown rate increased from (7.8 plus or minus 0.1) × 10(exp -13) Hz s(exp -1) to (8.1 plus or minus 0.1) × 10(exp -1)3 Hz s(exp -1). Significant (greater than 5 sigma) changes in the pulse profile and marginal (less than 3 sigma) changes in the emission spectrum occurred at the same time. There is also evidence for a small, steady flux increase over the 3 yr preceding MJD 55850. This is the first observation at gamma-ray energies of mode changes and intermittent behavior, observed at radio wavelengths for other pulsars. We argue that the change in pulsed gamma-ray emission is due to a change in emission beaming and we speculate that it is precipitated by a shift in the magnetic field structure, leading to a change of either effective magnetic inclination or effective current.

  13. Role of GacA, LasI, RhlI, Ppk, PsrA, Vfr and ClpXP in the regulation of the stationary-phase sigma factor rpoS/RpoS in Pseudomonas.

    Science.gov (United States)

    Bertani, Iris; Sevo, Milica; Kojic, Milan; Venturi, Vittorio

    2003-10-01

    RpoS is the stationary phase sigma factor responsible for increased transcription of a set of genes when bacterial cells enter stationary phase and under stress conditions. In Escherichia coli, RpoS expression is modulated at the level of transcription, translation, and post-translational stability whereas in Pseudomonas, previous studies have implicated four genetic loci ( psrA, gacA, lasI and rhlI) involved in rpoS transcription. In this report, the transcription, translation and proteins profiles of rpoS/RpoS were analyzed in response to growth phase of knockout genomic mutants in the P. aeruginosa transcriptional regulatory loci psrA, gacA, vfr, and in the las and rhl quorum-sensing systems. Gene expression and protein profiles were also analyzed in the ppk genomic mutant. This gene is responsible for the biosynthesis of polyphosphate, an alarmone involved in the regulation of RpoS accumulation in E. coli. Finally, the role of the ClpXP protease in RpoS regulation was also studied; in E. coli, this protease has been shown to rapidly degrade RpoS during exponential growth. These studies confirm the significant role of PsrA in rpoS transcription during the late-exponential and stationary growth phases, the probable role of Vfr in transcriptional repression during exponential phase, and the function of the ClpXP protease in RpoS degradation during exponential phase. GacA/GacS, the quorum-sensing systems, and the polyphosphate alarmone molecule were not significant in rpoS/RpoS regulation. These results demonstrate important similarities and differences with the regulation of this sigma factor in E. coli and in Pseudomonas.

  14. Research Research

    African Journals Online (AJOL)

    Research. May 2014, Vol. 6, No. 1 AJHPE 33. Research. Currently, radiography students are faced with the challenge of having to learn factual information, while ... A descriptive exploratory research design was used to collect both ..... Creswell J. Research Design: Quantitative, Qualitative and Mixed Methods Approaches.

  15. Researching research

    DEFF Research Database (Denmark)

    Pais, Alexandre; Valero, Paola

    2012-01-01

    of research by deploying Foucault’s notion of bio-politics - mainly to address the object “learning” - and Žižek’s ideology critique - to address the object “mathematics”. These theories, which have already been used in the field to research teaching and learning, have a great potential to contribute...

  16. Constraints on Estimation of Radius of Double Pulsar PSR J0737-3039A and Its Neutron Star Nuclear Matter Composition

    Science.gov (United States)

    Yang, Yi-Yan; Chen, Li; Linghu, Rong-Feng; Zhang, Li-Yun; Taani, Ali

    2017-12-01

    Not Available Supported by the National Program on Key Research and Development Project under Grant No 2016YFA0400801, the National Natural Science Foundation of China under Grant Nos 11173034, 11673023 and 11364007, the Fundamental Research Funds for the Central University, the Key Support Disciplines of Theoretical Physics of Guizhou Province Education Bureau under Grant No ZDXK[2015]38, and the Youth Talents Project of Science and Technology in Education Bureau of Guizhou Province under Grant No KY[2017]204.

  17. Structure and substrate specificity of the pyrococcal coenzyme A disulfide reductases/polysulfide reductases (CoADR/Psr): implications for S(0)-based respiration and a sulfur-dependent antioxidant system in Pyrococcus.

    Science.gov (United States)

    Herwald, Sanna; Liu, Albert Y; Zhu, Brian E; Sea, Kevin W; Lopez, Karlo M; Sazinsky, Matthew H; Crane, Edward J

    2013-04-23

    FAD and NAD(P)H-dependent coenzyme A disulfide reductases/polysulfide reductases (CoADR/Psr) have been proposed to be important for the reduction of sulfur and disulfides in the sulfur-reducing anaerobic hyperthermophiles Pyrococcus horikoshii and Pyrococcus furiosus; however, the form(s) of sulfur that the enzyme actually reduces are not clear. Here we determined the structure for the FAD- and coenzyme A-containing holoenzyme from P. horikoshii to 2.7 Å resolution and characterized its substrate specificity. The enzyme is relatively promiscuous and reduces a range of disulfide, persulfide, and polysulfide compounds. These results indicate that the likely in vivo substrates are NAD(P)H and di-, poly-, and persulfide derivatives of coenzyme A, although polysulfide itself is also efficiently reduced. The role of the enzyme in the reduction of elemental sulfur (S(8)) in situ is not, however, ruled out by these results, and the possible roles of this substrate are discussed. During aerobic persulfide reduction, rapid recycling of the persulfide substrate was observed, which is proposed to occur via sulfide oxidation by O(2) and/or H(2)O(2). As expected, this reaction disappears under anaerobic conditions and may explain observations by others that CoADR is not essential for S(0) respiration in Pyrococcus or Thermococcus but appears to participate in oxidative defense in the presence of S(0). When compared to the homologous Npsr enzyme from Shewanella loihica PV-4 and homologous enzymes known to reduce CoA disulfide, the phCoADR structure shows a relatively restricted substrate channel leading into the sulfur-reducing side of the FAD isoalloxazine ring, suggesting how this enzyme class may select for specific disulfide substrates.

  18. Researcher / Researched: Repositioning Research Paradigms

    Science.gov (United States)

    Meerwald, Agnes May Lin

    2013-01-01

    "Researcher / Researched" calls for a complementary research methodology by proposing autoethnography as both a method and text that crosses the boundaries of conventional and alternative methodologies in higher education. Autoethnography rearticulates the researcher / researched positions by blurring the boundary between them. This…

  19. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    This descriptive study investigated teachers' impleme. English classrooms ... Science, Technology and Arts Research Journ. Sci. Technol. ..... qualitative research methods were used to anal data. ..... handbook for language teachers. London.

  20. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    2015-09-22

    Sep 22, 2015 ... esearch Institute (OARI), Mechara Agricultural Research Center (McARC). P.O. Box: 19: Mechara , Ethiopia t Sciences, Haramaya University,P.O.Box:138, Dire Dawa, Ethiopia of Agriculture Research (EIAR), P.O.Box: 2003: Addis Ababa, Ethiopia .... laid out in a randomized complete block design (RCBD.

  1. Modeling the emission of the galactic very high energy {gamma}-ray sources G 1.9+0.3, G 330.2+1.0, HESS J1303-631 and PSR B1259-63/LS 2883 observed with H.E.S.S

    Energy Technology Data Exchange (ETDEWEB)

    Sushch, Iurii

    2012-10-19

    Recently, imaging atmospheric Cherenkov telescopes (IACTs) have discovered numerous new sources representing various source classes in the very high energy (VHE; E>100 GeV) sky. This work presents studies of representatives of three types of Galactic VHE emitters: the Supernova remnants (SNRs) G1.9+0.3 and G330.2+1.0, the pulsar wind nebula (PWN) HESS J1303.631 and the binary system PSR B1259.63/LS 2883. The analysis of the H.E.S.S. data and the broadband emission modeling are presented. G1.9+0.3 and G330.2+1.0 are synchrotron-dominated SNRs whose non-thermal X-ray emission implies that intensive particle acceleration occurs at their shock fronts. This makes them promising candidates for the detection at VHEs. They were observed by the High Energy Stereoscopic System (H.E.S.S.) yielding no signs of significant VHE {gamma}-ray emission from either SNR. The 99% confidence level upper limits on the TeV flux were determined. For an assumed spectral index of 2.5 the obtained upper limits are F{sub G1.9}(>260 GeV)<4.6 x 10{sup -13} cm{sup -2}s{sup -1} for G1.9+0.3 and F{sub G330}(>380 GeV)<1.6 x 10{sup -12} cm{sup -2}s{sup -1} for G330.2+1.0. Upper limits on the VHE emission provide constraints on the interior magnetic field in the context of a leptonic scenario and on the interstellar medium (ISM) density and cosmic-ray (CR) efficiency in a hadronic scenario. Lower limits on the interior magnetic fields were estimated at 15 {mu}G for G1.9+0.3 and 14 {mu}G for G330.2+1.0. In the case of the hadronic scenario, the H.E.S.S. upper limits are two orders of magnitude greater than the flux prediction. Obtained upper limits on the ISM densities are compatible with other estimates of the densities (from the thermal X-ray emission for G330.2+1.0 and from the expansion rate for G1.9+0.3). The CR efficiency cannot be constrained with the current H.E.S.S. upper limits. HESS J1303-631 is an initially unidentified H.E.S.S. source which was recently identified as a PWN associated with

  2. Artistic research, context research

    Directory of Open Access Journals (Sweden)

    Ricardo Benjamín Toledo Castellanos

    2012-06-01

    Full Text Available Some concepts in contemporary art works, dealing with some life aspects and passed through the sensitive and expressive test, are formulated in this paper and shed light on the foundation of researches about singular phenomenons of the existence. For this, it is argued that there are researches belonging to arts, fundamental researches that compromise the certainty of the assumptions where the sense system of a context has its bases (epoch, culture, nation, region. These researches come ahead of the researches of the rational-discursive enunciation fields, given that the last ones haven’t passed any protocol accepted yet by any community. To bring into play the certainty is done by a cognitive movement named by Martin Heidegger unconcealment [Unverborgenheit], and it consist on the interruption of the habituality of the beings who form the (trustworthy family setting to put into perspective the fundamental structures that allow to produce its sense. The unconcealment, typical in art and in creative actions, sets up an event that stops the solidity of the established (social, ethical, technical, scientific, philosophical order, and unleashes conditions for changing the lifestyles hold until then.

  3. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    seeds buried near the surface germinate with a higher percentage than those buried deeper (Benvenuti et al.,. 2001). Generally with increasing soil depth, soil aeration and temperature decline which may retard enzyme activation for cellular respiration which digests reserve food to complete seed germination. As research.

  4. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    independent, competent and practice oriented graduates of the school. Research and experience show that ... centered curricula are superior to those taught by teacher- centered approach in their education, long term .... discouraging teacher's performance in the classroom. Similarly, according to Lowry (1989), as cited in ...

  5. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    learning styles: Solutions based on international research. Insights on Learning Disabilities: From Prevailing. Theories to Validated Practices 5(1): 89-101. Edwards, C.J. Carr, S. and Siegel, W. (2006). Influences of experiences and training on effective teaching practices to meet the needs of diverse learners in schools.

  6. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    The process approach is based on the principle that learning is a process of discovery. As many research findings confirm, writing as a process is also process of discovering meaning. The process approach to writing has two major categories: the cognitive or classical approach and expressive or romantic approach (Yonas ...

  7. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    In-vitro Antimicrobial and Antitumor Activities of Stevia. Rebaudiana (Asteraceae) Leaf Extracts. Tropical Journal of Pharmaceutical Research 7(4): 1143-1149. Kaur, J., Rathinam, X., Kasi, M., Leng, K.M., Ayyalu, R.,. Kathiresan, S. (2010). Preliminary investigation on the antibacterial activity of mango (Mangifera indica L:.

  8. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    students in cooperative learning (one- in- five) at Mett achieve this objective, descriptive case study research m ... student learning through personal and active stud engagement in comparison to traditional instruct ..... Giving low status for themselves in CL, and spending their time on other /extra activities (eg. searching ...

  9. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    in dark color in processing and also prevents excessive loss of moisture, development of rots and excessive sprout growth. Therefore storage in mud blocket, above ground storage (circular form of mat) and simple silo of land constructed above the ground (investigated by. Holeta Research Center) can be used to prevent ...

  10. VLF/LF/MF Whispering Gallery Propagation Studies.

    Science.gov (United States)

    1981-09-09

    can be expressed as ry0 HGF = AnGn (z)Gn(z) - tn)1/2ki(tn - z)Ai(t - ). (8)n n n ~ 2 (Yo 0 ~ If both the transmitting and receiving antennas are...6503 10 PR 1/2 [n ~D v- h [a sin D/aJ AnGn (Z)Gn(;) exp 1--61 V/m, (9) n where all lengths are in meters and the radiated power, PR’ is in kilowatts...P.Greifinger) 2 Pacific-Sierra Research Corp., 1456 Cloverfield Boulevard, Santa Monica , CA 90404 (E. C. Field) I Johns Hopkins University, Applied Physics

  11. Research News

    Science.gov (United States)

    ... News & Progress Research News Share this page Facebook Twitter Email Research News Research News Quarterly Updates Research Call Archive ... best way to stay up to date on research and important advancements in MS is to sign up for email updates. Get Email Updates Get Email Updates Colophon ... Connection About the Society ...

  12. Research organizations

    DEFF Research Database (Denmark)

    Larsen, Bøje; Aagaard, Peter

    in Copenhagen - we argue that a post-rational form of research activity is emerging which revert these features. We term this new type of research "enchanted research", "sciencetainment" and "Mode2-b research". The factors that facilitate this development include the boring style of conventional research......, growing competition for research funds, more project funding compared to institutional funding and a demand for accountability. Countervailing forces also exist, however....

  13. Action Research and Interactive Research

    DEFF Research Database (Denmark)

    Svensson, lennart; Nielsen, Kurt Aagaard

    2006-01-01

    The authors present trends in Nordic action research. They ask critical questions in the development towards mode 2 and points out alternative roads for a scientific consolidation of action research and interactive research.......The authors present trends in Nordic action research. They ask critical questions in the development towards mode 2 and points out alternative roads for a scientific consolidation of action research and interactive research....

  14. Research Design

    DEFF Research Database (Denmark)

    2019-01-01

    Gunnar Scott Reinbacher (editor) Antology.  Research Design : Validation in Social Sciences. Gunnar Scott Reinbacher: Introduction. Research design and validity. 15p Ole Riis: Creative Research design. 16 p Lennart Nørreklit: Validity in Research Design. 24p Gitte Sommer Harrits: Praxeological kn...

  15. Fetal Research

    Science.gov (United States)

    Hansen, John T.; Sladek, John R.

    1989-11-01

    This article reviews some of the significant contributions of fetal research and fetal tissue research over the past 20 years. The benefits of fetal research include the development of vaccines, advances in prenatal diagnosis, detection of malformations, assessment of safe and effective medications, and the development of in utero surgical therapies. Fetal tissue research benefits vaccine development, assessment of risk factors and toxicity levels in drug production, development of cell lines, and provides a source of fetal cells for ongoing transplantation trials. Together, fetal research and fetal tissue research offer tremendous potential for the treatment of the fetus, neonate, and adult.

  16. Research Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Martens, Frederick H. [Argonne National Laboratory; Jacobson, Norman H.

    1968-09-01

    This booklet discusses research reactors - reactors designed to provide a source of neutrons and/or gamma radiation for research, or to aid in the investigation of the effects of radiation on any type of material.

  17. Research design

    NARCIS (Netherlands)

    Tobi, Hilde; Kampen, Jarl K.

    2017-01-01

    Many of today’s global scientific challenges require the joint involvement of researchers from different disciplinary backgrounds (social sciences, environmental sciences, climatology, medicine, etc.). Such interdisciplinary research teams face many challenges resulting from differences in

  18. Preeclampsia Research

    Science.gov (United States)

    ... NICHD Research Information Find a Study More Information Bullying About NICHD Research Information Find a Study More ... Education Program RELATED WEBSITES NIH.gov HHS.gov USA.gov ClinicalTrials.gov WEBSITE POLICIES Disclaimer FOIA Privacy ...

  19. [Genealogical Research.

    Science.gov (United States)

    McClure, Patricia Harlan

    Two Institute papers were concerned with genealogical research. "Manuscripts, Private Papers and Genealogical Research," deals with the handling and evaluation of unpublished and private papers in genealogical research. "The Genealogical Society of the Church of Jesus Christ of the Latter-Day Saints," discusses the Mormon…

  20. Ginning Research

    Science.gov (United States)

    There are four USDA-ARS labs involved in cotton harvesting, processing & fiber quality research; The Southwestern Cotton Ginning Research Laboratory (Mesilla Park, NM); The Cotton Production and Processing Unit (Lubbock, TX); The Cotton Ginning Research Unit (Stoneville, MS); and The Cotton Structur...

  1. Researcher Positioning

    DEFF Research Database (Denmark)

    Khawaja, Iram; Mørck, Line Lerche

    2009-01-01

    This article focuses on the complex and multilayered process of researcher positioning,specifically in relation to the politically sensitive study of marginalised and "othered"groups such as Muslims living in Denmark. We discuss the impact of different ethnic,religious, and racial backgrounds...... involvement by the researcher, which challenges traditional perspectives onresearch and researcher positioning. A key point in this regard is the importance ofconstant awareness of and reflection on the multiple ways in which one's positioningas a researcher influences the research process. Studying the other...... calls for closereflections on one's own position, theoretically, personally, and politically, taking intoaccount one's complicity in either overcoming or reproducing processes of otheringand marginalisation....

  2. Editorial -Research! Research! Research! What are Thou?

    Directory of Open Access Journals (Sweden)

    Ashok Shyam

    2013-04-01

    Full Text Available Being in field of Orthopaedic research since last 6 years, I have personally been witness to the rapid change in landscape of Othopaedic Research and also medical research in general. The sheer volumes of publications is overwhelming to the extent of being mostly ineffective in providing significant positive addition to the current literature. “There are too many variables” is one of my favorite phrase when I start to explain something to myself. Looking at as many variables as we can think of, makes us understand concepts within the limitations of given variables. Something similar to Ashby’s law that we spoke about in last Editorial [1]. However when we try to apply this to word ‘Research’ the amount of subjective stereotype that is associated with the word defeats all attempt to decipher and communicate clearly. Originally word Research derived from French ‘Researche’ simply means ‘Pursuit of Knowledge’. We as medical practitioners in search of better treatment for our patients are always in pursuit of knowledge. This knowledge is mostly build individually and is learned from individual experience and learning. This is a subjective body of knowledge and this is what makes one surgeon better than another. But is this ‘Research’? Yes it is Research and it serves the main purpose of medical research that is to improve the treatment given to patients. However this is a limited form of research, limited by individual’s ability and capacity. It also does not subject itself to rigorous ‘scientific methods’ and may not be acceptable to a community of ‘Modern Researchers’. Another form of Research of pursuit of knowledge is again from the clinics and from reading journals and books. A collaboration of clinical experience and written word adds a more thoughtful way of pursuing knowledge. This I think is the way majority of medical practitioners acquire knowledge. This keeps them updated and also helps them provide good

  3. Research Review: Doing Artistic Research

    Science.gov (United States)

    Serig, Dan

    2012-01-01

    In this review, the author focuses on the pragmatic consideration: How do artists do artistic research? Artistic research in the context of this review is about the connections and relationships among three primary domains: (1) the arts; (2) higher education; and (3) arts education. Broadly stated, all artists do research when they do art--whether…

  4. Is operations research really research?

    African Journals Online (AJOL)

    the world, such as earthquakes, diseases and human behaviour. Artificial phenomena are .... such as engineering, architecture and Information Systems, known as Design Research. 5 What is design research? Design Research ... Architectural knowledge con- sists of a pool of structural designs that achieve certain goals.

  5. Research management and research output

    Directory of Open Access Journals (Sweden)

    Anita Bosch

    2011-12-01

    Full Text Available Purpose: A study was conducted at two merged South African higher education institutions to determine which management factors, as identified in a literature study as well as through a factor analysis of survey data, were predictive of the dependent variable 'research output'. Problem investigated: Research output contributes to creating sustainability of knowledge of management sciences and therefore the active management of research is in the interest of progressive universities. Research management related activities are usually associated with measurable targets, detailed plans, rigorous evaluation and decisive action - all of which are observable (perhaps programmable behaviour also referred to as tangible factors. Authors argue that the tangible factors of any successful institution can be copied, technology can be bought, and in theory you should have an instantly thriving research institution. It is, however, clear that although many institutions have exactly the same technology and structure as their successful competitors, they still fail to succeed in increasing research output. Design and Research methodology or approach: A survey was distributed to n=411 and yielded a 49.6% response rate. A confirmatory reliability analysis as well as a factor analysis was conducted. Findings/implications: The empirical model that was derived through a factor analysis strengthens the argument that both tangible and intangible factors exist in a research environment. Tangible and intangible factors play a different role in predicting research output. The tangible factors are predictors of research output for non-research-active academics. The theoretical research output prediction model highlights predictors such as 'professional activities' and 'individual skills and competence' for specific groupings. The theoretical model indicates that the factors that predict research output are largely intrinsic to a researcher but could also be supported by

  6. Letterform research

    DEFF Research Database (Denmark)

    Beier, Sofie

    2016-01-01

    This paper looks into the history of letterform research and discusses why the discipline has yet to make the big break within design research. By highlighting two of the most popular focus areas (letter distinctiveness and the role of serifs) and by discussing various forms of methodological sho...... shortcomings, the paper suggests that future research into letterforms should (1) draw on results from the field of reading research (2) be based on test material informed by design knowledge and (3) move away from the former tendency of looking for universal answers.......This paper looks into the history of letterform research and discusses why the discipline has yet to make the big break within design research. By highlighting two of the most popular focus areas (letter distinctiveness and the role of serifs) and by discussing various forms of methodological...

  7. Animal research

    DEFF Research Database (Denmark)

    Olsson, I.A.S.; Sandøe, Peter

    2012-01-01

    This article presents the ethical issues in animal research using a combined approach of ethical theory and analysis of scientific findings with bearing on the ethical analysis. The article opens with a general discussion of the moral acceptability of animal use in research. The use of animals...... in research is analyzed from the viewpoint of three distinct ethical approaches: contractarianism, utilitarianism, and animal rights view. On a contractarian view, research on animals is only an ethical issue to the extent that other humans as parties to the social contract care about how research animals...... are faring. From the utilitarian perspective, the use of sentient animals in research that may harm them is an ethical issue, but harm done to animals can be balanced by benefit generated for humans and other animals. The animal rights view, when thoroughgoing, is abolitionist as regards the use of animals...

  8. Centering research

    DEFF Research Database (Denmark)

    Katan, Lina Hauge; Baarts, Charlotte

    idea, insofar as the ways students read and write need altering to correspond to the practice of research and prepare students accordingly. In the paper, we discuss therefore the possible challenges of grounding research-based teaching in reading, thinking and writing, as indicated by our empirical......Research-based teaching has long been a distinguishing trait of higher education. Engaging students in research-like processes has been employed to great effect in learning and continues to be encouraged by educational studies. The literature on this subject reflects how ‘technical’ or ‘field......’ exercises tend to dominate the common understandings of research-based learning. Here we address a specific area of inquiry overlooked by previous studies: whether and how reading, thinking and writing indeed share the same learning potentials as the practical foundation for research-based teaching...

  9. Researcher positioning

    DEFF Research Database (Denmark)

    Mørck, Line Lerche; Khawaja, Iram

    2009-01-01

    abstract  This article focuses on the complex and multi-layered process of researcher positioning, specifically in relation to the politically sensitive study of marginalised and ‘othered' groups such as Muslims living in Denmark. We discuss the impact of different ethnic, religious and racial...... political and personal involvement by the researcher, which challenges traditional perspectives on research and researcher positioning. A key point in this regard is the importance of constant awareness of and reflection on the multiple ways in which one's positioning as a researcher influences the research...... process. Studying the other calls for close reflections on one's own position, theoretically, personally, and politically, taking into account one's complicity in either overcoming or reproducing processes of othering and marginalisation. [i] We use the term (ethnic) minoritised, not as a distinction...

  10. Researching experiences

    DEFF Research Database (Denmark)

    Gjedde, Lisa; Ingemann, Bruno

    for researching experiences in a variety of settings ranging from the museum, to news photography, and interactive media. The research led to the development of a set of methodological tools and approaches we term the reflexivity lab. The interaction in the experimental situation between the media and body......, dialogue, moods, values and narratives have been investigated qualitatively with more than sixty informants in a range of projects. The processual methodological insights are put into a theoretical perspective and also presented as pragmatic dilemmas. Researching Experiences is relevant not only...... for students and researchers in media and communication studies but also for practitioners within the fields of media, communication and experience design....

  11. Researching experiences

    DEFF Research Database (Denmark)

    Gjedde, Lisa; Ingemann, Bruno

    , dialogue, moods, values and narratives have been investigated qualitatively with more than sixty informants in a range of projects. The processual methodological insights are put into a theoretical perspective and also presented as pragmatic dilemmas. Researching Experiences is relevant not only...... for students and researchers in media and communication studies but also for practitioners within the fields of media, communication and experience design....... for researching experiences in a variety of settings ranging from the museum, to news photography, and interactive media. The research led to the development of a set of methodological tools and approaches we term the reflexivity lab. The interaction in the experimental situation between the media and body...

  12. Clinical Research

    DEFF Research Database (Denmark)

    Christensen, Irene

    2016-01-01

    This paper is about the logic of problem solving and the production of scientific knowledge through the utilisation of clinical research perspective. Ramp-up effectiveness, productivity, efficiency and organizational excellence are topics that continue to engage research and will continue doing so...... for years to come. This paper seeks to provide insights into ramp-up management studies through providing an agenda for conducting collaborative clinical research and extend this area by proposing how clinical research could be designed and executed in the Ramp- up management setting....

  13. Action Research: Applied Research, Intervention Research, Collaborative Research, Practitioner Research, or Praxis Research?

    OpenAIRE

    Eikeland, Olav

    2012-01-01

    "This article relates common ways of conceptualising action research as 'intervention', 'collaboration', 'interactive research', 'applied research', and 'practitioner research' to a number of different ways of knowing, extracted from the works of Aristotle. The purpose is not to disavow any of these practices but to expand the philosophical, methodological, and theoretical horizon to contain the Aristotelian concept of praxis. It is claimed that praxis knowing needs to be comprehended in orde...

  14. Research Article

    African Journals Online (AJOL)

    2016-06-15

    Jun 15, 2016 ... Journal of Fundamental and Applied Sciences. ISSN 1112-9867. Available online at http://www.jfas.info. Research Article ..... Effects of cadmium, on antioxidant enzymes (genes) expect further research. 5. .... effects of cadmium, copper and zinc on the growth and photosynthesis of the freshwater diatom.

  15. Research Ethics

    Science.gov (United States)

    Dooly, Melinda; Moore, Emilee; Vallejo, Claudia

    2017-01-01

    Qualitative research, especially studies in educational contexts, often brings up questions of ethics because the study design involves human subjects, some of whom are under age (e.g. data collected in primary education classrooms). It is not always easy for young researchers to anticipate where ethical issues might emerge while designing their…

  16. Original Research

    African Journals Online (AJOL)

    home

    2014-05-18

    May 18, 2014 ... success. In other words, to the knowledge of the present researcher a scant attention is paid as to how self-efficacy and pedagogical success operates in our. EFL classroom teaching and learning contexts , and this provides adequate reason to conduct a similar research on the topic under investigation.

  17. Research Review

    Science.gov (United States)

    Serig, Dan, Ed.

    2010-01-01

    This research review is dedicated to the memory of William Safire (1929-2009). A visionary leader, Safire brought other visionaries, researchers, educators, artists, and policymakers together to explore the confluence of arts education and neuroscience. He fostered the new field of neuroeducation in his work as chair of The Dana Foundation in…

  18. Remote Research

    CERN Document Server

    Tulathimutte, Tony

    2011-01-01

    Remote studies allow you to recruit subjects quickly, cheaply, and immediately, and give you the opportunity to observe users as they behave naturally in their own environment. In Remote Research, Nate Bolt and Tony Tulathimutte teach you how to design and conduct remote research studies, top to bottom, with little more than a phone and a laptop.

  19. Research methodology

    DEFF Research Database (Denmark)

    Kuada, John

    This book deals with how students should use of research methods in their university projects. It aims at helping students in developing comprehensive research strategies for their projects. It also provides introduction to issues of philosophy of science as applied in the social sciences. That i...

  20. Research Study

    Science.gov (United States)

    Glick, Ashley

    2010-01-01

    Background: Action Research about my 2nd grade classroom in the Buffalo School District. I examined three areas of interest and tried to find some conclusions related to behavior management. Purpose: The purpose of this study is how will implementing procedures, rules, and consequences help improve student behavior. Research Design: Descriptive;…

  1. Original Research

    African Journals Online (AJOL)

    home

    2014-12-10

    Dec 10, 2014 ... Target Language (TL) in classrooms. For the investigation, a mixed-method research approach was used under the umbrella of pragmatic paradigm of research design. Four. Grade Nine History and Geography teachers were purposively selected for the study from two secondary schools in Nekemte town.

  2. Design Research

    DEFF Research Database (Denmark)

    Design Research is a new interdisciplinary research area with a social science orientation at its heart, and this book explores how scientific knowledge can be put into practice in ways that are at once ethical, creative, helpful, and extraordinary in their results. In order to clarify the common...... aspects – in terms of features and approaches – that characterize all strands of research disciplines addressing design, Design Research undertakes an in depth exploration of the social processes involved in doing design, as well as analyses of the contexts for design use. The book further elicits...... ‘synergies from interdisciplinary perspectives’ by discussing and elaborating on differing academic perspectives, theoretical backgrounds, and design concept definitions, and evaluating their unique contribution to a general core of design research. This book is an exciting contribution to this little...

  3. Are Gravitational Waves Spinning Down PSR J1023+0038?

    Science.gov (United States)

    Haskell, B; Patruno, A

    2017-10-20

    The pulsar J1023+0038 rotates with a frequency ν≈592  Hz and has been observed to transition between a radio state, during which it is visible as a millisecond radio pulsar, and a low-mass x-ray binary (LMXB) state, during which accretion powered x-ray pulsations are visible. Timing during the two phases reveals that during the LMXB phase the neutron star is spinning down at a rate of ν[over ˙]≈-3×10^{-15}  Hz/s, which is approximately 27% faster than the rate measured during the radio phase, ν[over ˙]≈-2.4×10^{-15}  Hz/s, and is at odds with the predictions of accretion models. We suggest that the increase in spin-down rate is compatible with gravitational wave emission, particularly with the creation of a "mountain" during the accretion phase. We show that asymmetries in pycnonuclear reaction rates in the crust can lead to a large enough mass quadrupole to explain the observed spin-down rate, which thus far has no other self-consistent explanation. We also suggest two observational tests of this scenario, involving radio timing at the onset of the next millisecond radio pulsar phase, when the mountain should dissipate, and accurate timing during the next LMXB phase to track the increase in torque as the mountain builds up. Another possibility is that an unstable r mode with an amplitude α≈5×10^{-8} may be present in the system.

  4. SMEX04 Aircraft Polarimetric Scanning Radiometer (PSR) Data, Arizona

    Data.gov (United States)

    National Aeronautics and Space Administration — Notice to Data Users: The documentation for this data set was provided solely by the Principal Investigator(s) and was not further developed, thoroughly reviewed, or...

  5. PSR/A Multiband Polarimetric Imaging, Wakasa Bay, Japan

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes brightness temperature data measured over the Sea of Japan, the Western Pacific Ocean, and the Japanese Islands in January and February 2003....

  6. CLPX-Airborne: Multiband Polarimetric Scanning Radiometer (PSR) Imagery

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides multiband polarimetric brightness temperature images over three 25 x 25 km Meso-cell Study Areas (MSAs) in Northern Colorado. The purpose of...

  7. Bioprocessing research

    Energy Technology Data Exchange (ETDEWEB)

    Kaufman, E.N.

    1996-06-01

    This section describes research and development activities performed for the Fossil Energy Bioprocessing Research Program. This program includes fundamental research for coal applications that investigates advanced reactor design for conversion of coal and coal liquids, the use of enzymes in pure organic media, and development of biological processes for the conversion of coal residuum. In addition, the program includes studies on advanced bioreactor systems for the treatment of gaseous substrates and the conversion to liquid fuels, removal of heteroatoms from heavy oils, renewable hydrogen production, remediation of oil containing soils. The program also includes natural gas and oil technology partnership support.

  8. Researching Undergraduate Social Science Research

    Science.gov (United States)

    Rand, Jane

    2016-01-01

    The experience(s) of undergraduate research students in the social sciences is under-represented in the literature in comparison to the natural sciences or science, technology, engineering and maths (STEM). The strength of STEM undergraduate research learning environments is understood to be related to an apprenticeship-mode of learning supported…

  9. Action Research and Interactive Research

    DEFF Research Database (Denmark)

    First part of the book is written by senior researchers on specific issues like validity, gender, new forms of organisations, methodologies and methods, earlier and new trends. - The second part of the book is written by doctoral students reporting experiences doing action research in their PhD-projects....

  10. Research Article

    African Journals Online (AJOL)

    2016-06-05

    Jun 5, 2016 ... Department of Physics, Science and Research Branch, Islamic Azad ... This phenomenon occurs in certain materials generally at low temperatures. .... electronic interaction and ρ0 is the residual resistivity considered as an ...

  11. Air Research

    Science.gov (United States)

    EPA's air research provides the critical science to develop and implement outdoor air regulations under the Clean Air Act and puts new tools and information in the hands of air quality managers and regulators to protect the air we breathe.

  12. Research vessels

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, P.S.

    by the research vessels RV Gaveshani and ORV Sagar Kanya are reported. The work carried out by the three charted ships is also recorded. A short note on cruise plans for the study of ferromanganese nodules is added...

  13. Research Reports

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Centers for Medicare and Medicaid Services (CMS) research efforts span many topics, methods, and interests. Some projects address the Agencys immediate...

  14. Original Research

    African Journals Online (AJOL)

    home

    2014-12-17

    3372 (Online). Science, Technology and Arts Research Journal. Sci. .... checked for consistency, using double mass curve method. The data were also tested for independence and stationarity by a fortran programme based on ...

  15. Research Article

    African Journals Online (AJOL)

    2016-06-18

    Jun 18, 2016 ... e. Libraries Resource Directory. We are listed under Research ... business on the Web,E-learning, increasing the users' communication with each other and .... selected domain frequency, subject, and profile keywords will be ...

  16. Disaster Research

    DEFF Research Database (Denmark)

    Given the tendency of books on disasters to predominantly focus on strong geophysical or descriptive perspectives and in-depth accounts of particular catastrophes, Disaster Research provides a much-needed multidisciplinary perspective of the area. This book is is structured thematically around key...... approaches to disaster research from a range of different, but often complementary academic disciplines. Each chapter presents distinct approaches to disaster research that is anchored in a particular discipline; ranging from the law of disasters and disaster historiography to disaster politics...... and anthropology of disaster. The methodological and theoretical contributions underlining a specific approach to disasters are discussed and illustrative empirical cases are examined that support and further inform the proposed approach to disaster research. The book thus provides unique insights into fourteen...

  17. Malaria Research

    Science.gov (United States)

    ... with facebook share with twitter share with linkedin Malaria Go to Information for Researchers ► Malaria is a ... for the disease. Why Is the Study of Malaria a Priority for NIAID? Roughly 3.2 billion ...

  18. Researching Experiences

    DEFF Research Database (Denmark)

    Gjedde, Lisa; Ingemann, Bruno

    , dialogue, moods, values and narratives have been investigated qualitatively with more than sixty informants in a range of projects. The processual methodological insights are put into a theoretical perspective and also presented as pragmatic dilemmas.      Researching Experiences is relevant not only...... for students and researchers in media and communication studies but also for practitioners within the fields of media, communication and experience design....... for researching experiences in a variety of settings ranging from the museum, to news photography, and interactive media. The research led to the development of a set of methodological tools and approaches we term the ReflexivityLab. The interaction in the experimental situation between the media and body...

  19. Phase-Resolved Spectra of PSR B0525+21 and PSR B2020+28 JL ...

    Indian Academy of Sciences (India)

    Jiao-Ke (2009)), GDUPS (2009) and NFSC project 10673021. References. Chen, J. L. et al. 2007, Chinese J. Astron. Astrophys., 7, 789. Cordes, J. M. 1978, Astrophys. J., 222, 1006. Kuzmin, A. D., Izvekova, V. A., et al. 1998, Astron. Astropys.

  20. Qualitative research

    OpenAIRE

    Baxi, R. K.

    2013-01-01

    QR Methodology learning and its application to the field of public health/community medicine research and practice has been comparatively a recent phenomenon. It has been a bastion of Social science. Our increasing acceptance of ever increasing influence of sociobehavioral factors on health and health related issues, have led us to accept the use of QR methodology to examine some of it in the research settings. Unfortunately, so fa...

  1. Research agenda.

    Science.gov (United States)

    2008-12-01

    This issue of JERHRE focuses on two topics that have been largely ignored-trust in the human research industry and structural factors that affect the efficacy of ethical review of human research (i.e., factors that are not under the control of ethics committee members, such as the funding of committee resources and the provision of clear workable regulations). Trust and an adequate ethical infrastructure are integral to one another. Ethical capacity does not reside with an ethics committee alone, but springs from four foundations of ethical research. It derives from (a) national bodies that regulate research and clarify the ethical principles that are promulgated, (b) the institutional research administrations that finance and build the needed infrastructure, (c) the ethics committees that struggle to operate within this system, and (d) the individual disciplines and departments that should work collaboratively with investigators and ethics committees to provide needed expertise. Research on trust and adequate ethical review needs to be mindful of the larger dynamic system within which ethical oversight occurs, and how failure of any of its four major components weakens its other components.

  2. Quantitative research.

    Science.gov (United States)

    Watson, Roger

    2015-04-01

    This article describes the basic tenets of quantitative research. The concepts of dependent and independent variables are addressed and the concept of measurement and its associated issues, such as error, reliability and validity, are explored. Experiments and surveys – the principal research designs in quantitative research – are described and key features explained. The importance of the double-blind randomised controlled trial is emphasised, alongside the importance of longitudinal surveys, as opposed to cross-sectional surveys. Essential features of data storage are covered, with an emphasis on safe, anonymous storage. Finally, the article explores the analysis of quantitative data, considering what may be analysed and the main uses of statistics in analysis.

  3. Research Paper

    African Journals Online (AJOL)

    AJTCAM

    Research Paper. THE EFFECT OF AQUEOUS EXTRACTS OF HIBISCUS SABDARIFFA (SORREL) CALYCES ON. HEAMATOLOGICAL PROFILE AND ORGAN ..... 17. Reinhold, J. G. (1953). Estimation of plasma total proteins and albumin. In. standard Methods in Clinical. Chemistry. Academic press, N.Y., pp. 88-90. 18.

  4. Research Article

    African Journals Online (AJOL)

    2017-01-01

    Jan 1, 2017 ... We are listed under Research Associations category. ... The problem arises from the necessity to explain large diversifications of these coins as well as the differences in compositions, weights and physical ... fast, low minimum detection limits (MDLs) for a very broad range of elements in the Periodic.

  5. Research Article

    African Journals Online (AJOL)

    2016-01-01

    Jan 1, 2016 ... Libraries Resource Directory. We are listed under Research Associations category. ... Areas affected by mining activities typically support a sparse natural vegetation cover, principally as a result of an elevated concentration of ... The mine was closed in 1992 due to the depletion of reserves. Fig.1. Location ...

  6. Quantitative research

    DEFF Research Database (Denmark)

    Wigram, Anthony Lewis

    2003-01-01

    possible and desirable. It is not just a type of research done in a laboratory, or by PhD students. Some for of reliable measurement can be applied to many clinical situationsto evaluate the effects of therapy over time, or the difference between clients who receive therapy and those who don't. Evaluating...

  7. Original Research

    African Journals Online (AJOL)

    2013-09-28

    Sep 28, 2013 ... electric resistance heaters. The electrical systems on most cars provide enough energy or power to heat the catalytic converter fast enough. So, in this research the main converter remains its usual position, whereas the heated catalyst is placed close to the exhaust manifold. The EHMC quickly reaches ...

  8. Research Article

    African Journals Online (AJOL)

    2016-06-18

    Jun 18, 2016 ... 1 and N. Jokar. 1 f Electrical and Computer Engineering, Safashahr Branch, Islamic Az. University, Safashahr, Iran ... shahr Branch, Islamic Azad nd paper search engines such as ..... for Topic Modeling and Clustering of Research Papers”, In the proceeding of the 2011 third. Conference on Data Mining and ...

  9. Original Research

    African Journals Online (AJOL)

    Non-contacting biometrics is the inevitable trend for the research and the development of status identification. The error rate of iris recognition is the lowest in all the biometrics according to the statistics. Daugman presented an algorithm that needs to process the two dimensional information of the texture, and increases ...

  10. Research Article

    African Journals Online (AJOL)

    2016-06-14

    Jun 14, 2016 ... ccording to economic and safety use of available software is one s basis, we have investigated the n the body of earth dam in Baft od through GeoStudio software and dimensions of cutoff wall flow. The soil type in terms of icate that the one-time reduction io software, uplift pressure. Jo. Research Article ...

  11. Research Article

    African Journals Online (AJOL)

    2016-06-18

    Jun 18, 2016 ... doi: http://dx.doi.org/10.4314/jfas.v8i2s.141. Journal of Fundamental and Applied Sciences. ISSN 1112-9867. Available online at http://www.jfas.info. Research Article ..... the Association for Computational Linguistics: Human Language Technologies-Volume 1 (pp. 142-150). Association for Computational ...

  12. Research Article

    African Journals Online (AJOL)

    2018-01-01

    Jan 1, 2018 ... Glasses in. ≤x≤15 mol%), have ve been investigated by X-ray differential thermal analysis g and bending vibrations are and SO4. The thermal ential thermal analysis (DTA). /total BO groups ratio of the UV cut off shift to higher ical band gap decrease with the spectroscopy, differential. Research Article.

  13. Research Article

    African Journals Online (AJOL)

    2016-06-05

    Jun 5, 2016 ... Department of Biological Sciences, Bushehr branch, Islamic Azad University, Bushehr,. Bushehr, Iran. 2,3,5. Department of Crop Science, Faculty of Agriculture, Universiti Putra Malaysia,. 43400 Serdang, Selangor, Malaysia. 4. Department of Seed and Plant Production and Breeding Research, Agricultural ...

  14. Original Research

    African Journals Online (AJOL)

    The environmental degradation all over the world has led the researchers to work towards the development of Low Emission ... The EHMC quickly reaches high temperature levels due to the heat supply from external source, sensible heat of the exhaust and the heat generated by the exothermic oxidation. This in turn helps ...

  15. Research Review

    OpenAIRE

    Anonymous,

    1981-01-01

    Research Reviewed: "Statistical Estimation of Firm-Level Demand Functions: A Case Study in an Oligopolistic Industry"; "Predicting Debt Reschedulings in Developing Countries"; "Special Lectures in Economics"; "Analysis of Economic Time Series: A Synthesis"; "The Planning of Investment Programs in the Fertilizer Industry"

  16. Original Research

    African Journals Online (AJOL)

    home

    2014-12-23

    Dec 23, 2014 ... ISSN: 2226-7522(Print) and 2305-3372 (Online). Science, Technology and Arts Research Journal. Sci. Technol. Arts Res. J., Oct-Dec 2014, 3(4): 172- ... 1School of Psychology, Addis Ababa University, P.O. Box: 33617, Addis Ababa, Ethiopia ..... and self-regulation: Taking an evolutionary perspective on.

  17. Research Article

    African Journals Online (AJOL)

    , and Debabeche, M. Journal of Hydraulic Research, 41(3): (2003), 97–103. [3] Bakhmeteff B.A, and Matzke; A.E. Transactions, ASME, 60(HYD-60-1), (1938), 111-118. [4] Hager W.H, Water Science and Technology Library, ...

  18. Original Research

    African Journals Online (AJOL)

    This research showed only 33.9% of the respondents were found to have good nutritional practices during their pregnancy. There was a positive significant relation between information about nutrition and family size and nutritional practices of mothers during pregnancy (P<0.001). The practices of pregnant mothers about ...

  19. Population Research.

    Science.gov (United States)

    National Inst. of Child Health and Human Development (NIH), Bethesda, MD.

    The scope of population research as carried on by the National Institute of Child Health and Human Development (NICHD) is set forth in this booklet. Population problems of the world, United States, and the individual are considered along with international population policies based on voluntary family planning programs. NICHD goals for biological…

  20. Original Research

    African Journals Online (AJOL)

    2013-12-17

    Dec 17, 2013 ... On the other hand Edossa et al., (2013b) proposed nearly 75 kg N ha-1 and 48 kg P ha-1 for verification for tomato production around Melkassa and similar soil types. This probably indicates that research based recommended fertilizer application rate and schedule for each major vegetable crop does not ...

  1. Research supervision

    African Journals Online (AJOL)

    the development of postgraduate (PG) students as competent knowledge generators ... is expected to transform research candidates into knowledge producers and .... review was higher compared with that received for the theoretical or conceptual framework. A quarter of the respondents (25%; n=14) strongly agreed, while.

  2. Research Article

    African Journals Online (AJOL)

    Published online: 15 May 2016. ABSTRACT. This study evaluates effects of various weeds control methods and nitrogen fertilizer resources on density and dry weight of pigweed and the performance of corn forage as factorial in full random block design with 3 repetitions in research farm of Ferdowsi Mashhad. University in ...

  3. Research Article

    African Journals Online (AJOL)

    2016-06-11

    Jun 11, 2016 ... This research aimed to study the effects of window position on natural cross ventilation in Vernacular ... Keywords: natural ventilation; window; vernacular architecture; temperate and wet climate. 1. ... energy consumption using local materials causes environmental sustainability and durability of buildings ...

  4. Developmental Research

    NARCIS (Netherlands)

    Klaassen, Kees; Kortland, Koos

    2015-01-01

    Developmental research is a particular way of addressing the basic questions of why and how to teach what to whom. It involves a cyclical process of small-scale in-depth development and evaluation, at a content-specific level, of exemplary teaching-learning sequences. It aims to produce an

  5. Research Note:

    DEFF Research Database (Denmark)

    Behuria, Pritish; Buur, Lars; Gray, Hazel

    2017-01-01

    about its core conceptual and methodological features. This Research Note starts by setting out our understanding of political settlements and provides an overview of existing political settlements literature on African countries. The note then explores how the key concept of ‘holding power’ has been...

  6. Original Research

    African Journals Online (AJOL)

    home

    2014-12-23

    Dec 23, 2014 ... 2School of Animal and Range Sciences, Haramaya University, P.O. Box 138, Dire Dawa, Ethiopia ... beings also consume. However, the nutritional merit of the fruits as livestock feed, particularly for pigs' was not studied yet. There was. Original Research .... The pork sample for sensory test was taken from.

  7. RESEARCH REPORTS

    African Journals Online (AJOL)

    stagnated or declined over the same period (Botswana National Productivity. Centre, 1997). The performance ... This study is concerned with the productivity of nurses working within the. Primary Health Care System, ..... RESEARCH REPORTS 157 concluded that self—managing teams tend to increase group performance.

  8. Descriptive Research

    DEFF Research Database (Denmark)

    Wigram, Anthony Lewis

    2003-01-01

    starts will allow effect size calculations to be made in order to evaluate effect over time. Given the difficulties in undertaking controlled experimental studies in the creative arts therapies, descriptive research methods offer a way of quantifying effect through descriptive statistical analysis...

  9. Original Research

    African Journals Online (AJOL)

    home

    2014-11-30

    Nov 30, 2014 ... Science, Technology and Arts Research Journal. Sci. Technol. Arts Res. ... validated as per ICH guidelines with respect to specificity, linearity, accuracy, precision, robustness and ..... Table 3: Precision and accuracy for the determination of OFL and CEF in bulk form using the RP-HPLC method. Analyte.

  10. Research Article

    African Journals Online (AJOL)

    2016-07-18

    Jul 18, 2016 ... 1. , N. Noushadi. 2,*. 1. M.A student in Educational Research, Yasouj University, Yasouj, Iran. 2 ... Mentoring is a unique relation in which people can share their personal experiences .... The account of Mentor in The Odyssey leads us to make several conclusions about the activity which bears his name.

  11. Research Article

    African Journals Online (AJOL)

    2016-06-05

    Jun 5, 2016 ... ISSN 1112-9867. Available online at http://www.jfas.inf ndamental and Applied Sciences is licensed under a Creative Commons Attribution-NonCom. License. Libraries Resource Directory. We are listed under Research Associations category. AGNETIC WAVES CAUSED BY TECTONIC EARTH MOVEME.

  12. Research Article

    African Journals Online (AJOL)

    2016-06-18

    Jun 18, 2016 ... APPLICATIONS OF SSAFT EOS FOR DETERMINATION OF THE SOLUBILITIES ... systems. In this research, four solid solubility of benzoic acid, naphthalene, pyrene and. Phenanthrene in supercritical carbon dioxide have been studied, SSAFT EoS has ... reported by binary negative interaction parameter.

  13. Research Article

    African Journals Online (AJOL)

    2016-06-11

    Jun 11, 2016 ... Amirkabir University of Technology, Structure and Earthquake Research Center,. 2. Amirkabir University ... passive defense is immunizing and reducing vulnerability of people's necessary infrastructures so that gradually creates secure conditions, such important measurements have been done or are being ...

  14. Research Results

    Science.gov (United States)

    2012-12-01

    Achievements in Sino-German Interdisciplinary Major Research Project Published by Small A Conserved Proline Switch on the Ribosome Facilitates the Recruitment and Binding of trGTPases Air Pollution Contributes in Sunshine Dimming in China Role of Lymphatic Trafficking and Biodistribution Soft Fibrin Gels Promote Selection and Growth of Tumorigenic Cells Targeted Therapy: The New Lease on Life for Acute Promyelocytic Leukemia, and Beyond The Structural Basis for the Sensing and Binding of Cyclic di-GMP by STING Research on Atomic-Scale Investigation of Li Storage Mechanism in Spinel Li4Ti5O12 NSFC Funded Project Made Significant Progress in Intelligent Nanomaterial and Device Palaeobotany and the Evolution of the Monsoon in China Non Heme System Asymmetric Epoxidation Reaction Made Progress Rapid Advancement of Immunology Study in China Chinese Experts Successfully Produced Transgenic Animals from Haploid Embryonic Stem Cells

  15. Qualitative research.

    Science.gov (United States)

    Maher, Lisa; Dertadian, George

    2017-08-07

    This narrative review aims to highlight key insights from qualitative research on drug use and drug users by profiling a selection of classic works. Consensus methods were used to identify and select four papers published in 1938, 1969, 1973 and 1984 considered to be classics. These landmark qualitative studies included the first account of addiction as a social process, demonstrating that people have meaningful responses to drug use that cannot be reduced to their pharmacological effects; the portrayal of inner-city heroin users as exacting, energetic and engaged social agents; identification of the interactive social learning processes involved in becoming a drug user; the application of the 'career' concept to understanding transitions and trajectories of drug use over time; and the articulation of a framework for understanding drug use that incorporates the interaction between pharmacology, psychology and social environments. These classic sociological and anthropological studies deployed qualitative research methods to show how drug use is shaped by complex sets of factors situated within social contexts, viewing drug users as agents engaged actively in social processes and worlds. Their findings have been used to challenge stereotypes about drug use and drug users, develop a deeper understanding of drug use among hidden, hard-to-research and under-studied populations, and provide the foundations for significant developments in scientific knowledge about the nature of drug use. They continue to retain their relevance, providing important correctives to biomedical and behaviourist paradigms, reminding us that drug use is a social process, and demonstrating how the inductive approach of qualitative research can strengthen the way we understand and respond to drug use and related harms. © 2017 Society for the Study of Addiction.

  16. Research Methods

    Science.gov (United States)

    1992-01-01

    WasI* Ion Headquarters Services. Directorate for Information Operations anc: 1fngton, VA 22202-4302, and to the Office of Management and Budget...Post . associate editors. Jeffrey D. Orossman and Jan Walravsn. 0. ca. -- (Defense research series ; v. 31 "Publisheb in cooperat ion with NATO...In S.S. Williamson, M. Hoke, G. Stroink, & M. Kotani (Eds.), Advances in biomagnetism . New York: Plenum. Lewis, G.W., Trejo, L.J., Nunez, P

  17. Dialogue Research

    DEFF Research Database (Denmark)

    Duelund, Peter

    1991-01-01

    Departing from Anthony Giddens´s theory of structuration and the concept double hermeneutics and Jürgen Habermas´s Theory of Communicative Actions the article specifies theories and methods af dialogue as method in the humanities and social sciences. The article concludes by pointing at dialogues...... as a new theoretical, methodological and empirical research concept i an society where the traditional planning instruments have failed....

  18. Researching experiences

    DEFF Research Database (Denmark)

    Gjedde, Lisa; Ingemann, Bruno

    In the beginning was - not the word - but the experience. This phenomenological approach provides the basis for this book, which focuses on how a person-in-situation experiences and constructs meaning from a variety of cultural visual events. This book presents video-based processual methods for ...... for students and researchers in media and communication studies but also for practitioners within the fields of media, communication and experience design....... for researching experiences in a variety of settings ranging from the museum, to news photography, and interactive media. The research led to the development of a set of methodological tools and approaches we term the reflexivity lab. The interaction in the experimental situation between the media and body......In the beginning was - not the word - but the experience. This phenomenological approach provides the basis for this book, which focuses on how a person-in-situation experiences and constructs meaning from a variety of cultural visual events. This book presents video-based processual methods...

  19. Researching Experiences

    DEFF Research Database (Denmark)

    Gjedde, Lisa; Ingemann, Bruno

    In the beginning was - not the word - but the experience. This phenomenological approach provides the basis for this book, which focuses on how a person-in-situation experiences and constructs meaning from a variety of cultural visual events. This book presents video-based processual methods for ...... for students and researchers in media and communication studies but also for practitioners within the fields of media, communication and experience design....... for researching experiences in a variety of settings ranging from the museum, to news photography, and interactive media. The research led to the development of a set of methodological tools and approaches we term the ReflexivityLab. The interaction in the experimental situation between the media and body......In the beginning was - not the word - but the experience. This phenomenological approach provides the basis for this book, which focuses on how a person-in-situation experiences and constructs meaning from a variety of cultural visual events. This book presents video-based processual methods...

  20. Researching Experiences

    DEFF Research Database (Denmark)

    Gjedde, Lisa; Ingemann, Bruno

    In the beginning was - not the word - but the experience. This phenomenological approach provides the basis for this book, which focuses on how a person-in-situation experiences and constructs meaning from a variety of cultural visual events. This book presents video-based processual methods for ...... for students and researchers in media and communication studies but also for practitioners within the fields of media, communication and experience design.......In the beginning was - not the word - but the experience. This phenomenological approach provides the basis for this book, which focuses on how a person-in-situation experiences and constructs meaning from a variety of cultural visual events. This book presents video-based processual methods...... for researching experiences in a variety of settings ranging from the museum, to news photography, and interactive media. The research led to the development of a set of methodological tools and approaches we term the ReflexivityLab. The interaction in the experimental situation between the media and body...

  1. RESEARCH COMMUNITIES

    Directory of Open Access Journals (Sweden)

    HUGO ESCOBAR-MELO

    2006-05-01

    Full Text Available This article constitutes an anthology of the research in the Department of Psychology of the UniversidadJaveriana and it takes as point of consultations the book Saber, sujeto y sociedad: Una década de investigación enPsicología published in the year 2006 by the Editorial Pontificia Universidad Javeriana as a collective work;it shows the research itinerary of the groups and authors which have worked in multiple problematicnucleus like the affective bonds in terms of emotional security and care, the psychological welfare as axleof the psychology of the health, the meanings and bonds to build cultures of peace, the public opinionthat mobilizes different senses in the world, the culture of the transport, the subjetivation and the speechthat mean to the work, the experimented body in the woman, the kidnapping and their ghost of thedeath, the family as a person networks linked by the language, person, relationships and psychic operation,quality of life, numeric thought, experimental psychology and cognitive neuropsycology.Without a doubt all these problematic nucleus seemingly diverse but crossed by the significance andsignificant implication, they have conformed a true disciplinary intersection, to the style of the geometric,convergent and strong cobwebs of the spiders. It also includes the present anthology, the basic principlesof a research culture and their most visible production in the Universitas Psychologica magazine.

  2. Research Note:

    DEFF Research Database (Denmark)

    Behuria, Pritish; Buur, Lars; Gray, Hazel

    2017-01-01

    its core conceptual and methodological features. This Research Note starts by setting out our understanding of political settlements and provides an overview of existing political settlements literature on African countries. The note then explores how the key concept of ‘holding power’ has been...... the importance of studying economic structure, ideology, violence rights, and rents as sources of holding power. The overall contribution of the note is to illustrate the varied strategies used in studying political settlements and to place them in conversation with one another....

  3. Survey research.

    Science.gov (United States)

    Krosnick, J A

    1999-01-01

    For the first time in decades, conventional wisdom about survey methodology is being challenged on many fronts. The insights gained can not only help psychologists do their research better but also provide useful insights into the basics of social interaction and cognition. This chapter reviews some of the many recent advances in the literature, including the following: New findings challenge a long-standing prejudice against studies with low response rates; innovative techniques for pretesting questionnaires offer opportunities for improving measurement validity; surprising effects of the verbal labels put on rating scale points have been identified, suggesting optimal approaches to scale labeling; respondents interpret questions on the basis of the norms of everyday conversation, so violations of those conventions introduce error; some measurement error thought to have been attributable to social desirability response bias now appears to be due to other factors instead, thus encouraging different approaches to fixing such problems; and a new theory of satisficing in questionnaire responding offers parsimonious explanations for a range of response patterns long recognized by psychologists and survey researchers but previously not well understood.

  4. Research Brief.

    Science.gov (United States)

    Schoenfelder, Erin; McCabe, Connor; Fife, Aurora; Herzig, Lisa; Ahrens, Kym

    2017-01-01

    Adolescents with ADHD are at risk of functional problems that may be mitigated by consistent ADHD treatment. This study pilots a brief intervention for adolescents with ADHD and their parents to increase treatment knowledge and family motivation to seek treatment. The 3-hr curriculum was developed by a multidisciplinary team and included psychoeducation, goal setting, and motivational interviewing. Fifteen adolescents and 20 caregivers participated in the workshop, completed pre- and post-test assessments, and reported on acceptability. Acceptability and satisfaction with the intervention were high. Perceived knowledge of ADHD increased post intervention; stigma was unchanged. Parents reported more acceptability of stimulant medications and less willingness to use special diets or cognitive games. Family feedback informed modifications to the curriculum. The Teen ADHD Workshop is a feasible and acceptable intervention to increase knowledge of ADHD and evidence-based treatments. Further research will evaluate effects on treatment participation.

  5. Types of Cancer Research

    Science.gov (United States)

    An infographic from the National Cancer Institute (NCI) describing the four broad categories of cancer research: basic research, clinical research, population-based research, and translational research.

  6. Research Areas: Liver Disease

    Science.gov (United States)

    ... Advisors, and committees that coordinate research activities Research Areas Overview of NIDDK activities in each major research area, including research advances, research coordination, and health information ...

  7. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Research & Training Medical Research Initiatives Science Highlights Science Education Research in NIH Labs & Clinics Training Opportunities Library Resources Research Resources Clinical Research Resources Safety, ...

  8. Novel research

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Author Robert Harris and film director Paul Greengrass visited CERN on 26 April, passing by SM18 as well as the CCC and the ATLAS control room.   Film director Paul Greengrass (left) and author Robert Harris (right). Author Robert Harris and film director Paul Greengrass visited CERN on 26 April as part of their preliminary research on an idea that Harris has for a book, which Greengrass might turn into a film. One of the characters would be a theoretical physicist from CERN – but to say more than that might give away the story! There is definite irony in the fact that their visit was delayed for a week by the ash from the Icelandic volcanic eruption. Harris is well known for several historical novels, including ‘Pompeii’, which tells the story of a fictional hydraulic engineer at the time of the eruption of Mount Vesuvius in 79 AD. His latest book, ‘The Ghost’, became a film directed by Roman Polanski, while the latest film from Greengrass is &a...

  9. Research Results

    Science.gov (United States)

    2012-01-01

    In situ Oxidation Study of Pt (110) and Its Interaction with CO Chinese Scientists Published a Paper on Prevention of Drug Craving and Relapse by Memory Retrieval-extinction Procedure in Science Series Papers Published in Energy Policy: Modeling Energy Use of China's Road Transport and Policy Evaluation Breakthrough in the Ambient Catalytic Destruction of Formaldehyde Novel Findings for High Altitude Adaptation from the Yak Genome Binary Colloidal Structures Assembled through Ising Interactions Reemergence of superconductivity at 48K in Compressed Iron Selenide Based Superconductors Nucleosomes Suppress Spontaneous Mutations Base-Specifically in Eukaryotes Single-Chain Fragmented Antibodies Guided SiRNA Delivery in Breast Cancer Does Yeast Suicide? China Scientists Developed Important Methodologies for Spatiotemporal Detecting and Manipulating of Cellular Activities Scorpions Inspire Chinese Scientists in Making Bionic Non-eroding Surfaces for Machinery Research on Phylogenetic Placement of Borthwickia and Description of a New Family of Angiosperms, Borthwickiaceae Plasmoid Ejection and Secondary Current Sheet Generation from Magnetic Reconnection in Laser-plasma Interaction Cotton Bollworm Adapts to Bt Cotton via Diverse Mutations A Histone Acetyltransferase Regulates Active DNA Demethylation in Arabidopsis

  10. Research practices and assessment of research misconduct

    NARCIS (Netherlands)

    Hartgerink, C.H.J.; Wicherts, J.M.

    2016-01-01

    This article discusses the responsible conduct of research, questionable research practices, and research misconduct. Responsible conduct of research is often defined in terms of a set of abstract, normative principles, professional standards, and ethics in doing research. In order to accommodate

  11. Cancer Research UK | IDRC - International Development Research ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Cancer Research UK. Cancer Research UK. https://www.cancerresearchuk.org/. The Economics of Tobacco Control Research Initiative. The Economics of Tobacco Control Research Initiative funds innovative fiscal policy research supporting tobacco control in low and middle-income countries. View more. The Economics ...

  12. Research Productivity and Academics' Conceptions of Research

    Science.gov (United States)

    Brew, Angela; Boud, David; Namgung, Sang Un; Lucas, Lisa; Crawford, Karin

    2016-01-01

    This paper asks the question: do people with different levels of research productivity and identification as a researcher think of research differently? It discusses a study that differentiated levels of research productivity among English and Australian academics working in research-intensive environments in three broad discipline areas: science,…

  13. Training Researchers To Commercialize Research Results.

    Science.gov (United States)

    van der Sijde, P. C.; Cuyvers, R.

    2003-01-01

    A training course was designed to prepare researchers for research commercialization for researchers. It introduces concepts involved in the publishing of knowledge such as protection of intellectual property, spin-off companies, and working with commercial companies. (JOW)

  14. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Record Research & Training Medical Research Initiatives Science Highlights Science Education Research in NIH Labs & Clinics Training Opportunities Library Resources Research Resources Clinical Research Resources Safety, Regulation ...

  15. Succeeding with interactive research

    DEFF Research Database (Denmark)

    Krogh, Andreas Hagedorn; Nielsen, Morten Velsing

    2017-01-01

    Increasingly, social science research is carried out in collaboration with partners outside universities, yet research methodology is lacking on how to manoeuvre in a terrain where multiple actors set expectations for research. This article conceptualizes interactive research as research with and......Increasingly, social science research is carried out in collaboration with partners outside universities, yet research methodology is lacking on how to manoeuvre in a terrain where multiple actors set expectations for research. This article conceptualizes interactive research as research...

  16. Researching Research: Mathematics Education in the Political

    Science.gov (United States)

    Pais, Alexandre; Valero, Paola

    2012-01-01

    We discuss contemporary theories in mathematics education in order to do research on research. Our strategy consists of analysing discursively and ideologically recent key publications addressing the role of theory in mathematics education research. We examine how the field fabricates its object of research by deploying Foucault's notion of…

  17. Research tools | IDRC - International Development Research Centre

    International Development Research Centre (IDRC) Digital Library (Canada)

    Through training materials and guides, we aim to build skills and knowledge to enhance the quality of development research. We also offer free access to our database of funded research projects, known as IDRIS+, and our digital library. Our research tools include. Guide to research databases at IDRC: How to access and ...

  18. Changing Research Practices and Research Infrastructure Development

    Science.gov (United States)

    Houghton, John W.

    2005-01-01

    This paper examines changing research practices in the digital environment and draws out implications for the development of research infrastructure. Reviews of the literature, quantitative indicators of research activities and our own field research in Australia suggest that there is a new mode of knowledge production emerging, changing research…

  19. Connecting Research and Researchers: ORCID Identifiers (Invited)

    Science.gov (United States)

    Haak, L.; Bryant, R.

    2013-12-01

    Lack of standards for identification of researchers is a major challenge for the research community. It is difficult not only to unambiguously associate researchers with their own work, but also to track use and re-use of those works. The goal of ORCID (orcid.org) is to connect research with researchers, ultimately saving researchers time in entering data, improving discoverability, and facilitating the flow of research information and data re-use. ORCID is a community-driven non-profit organization that provides an open registry of unique persistent identifiers for researchers. We work collaboratively with the research community to embed these identifiers in research workflows, including manuscript submission, grant application, and data set deposit. In this presentation, we will provide an overview of ORCID, an in particular how it is being used as a switchboard to connect existing but fragmented researcher identifiers. ORCID also provides researchers search and link tools to link their ORCID identifier to their existing datasets, grants, other research works, and an automated method to link new works to their identifier. ORCID is fundamental to solving the name ambiguity problem for researchers and scholars. Together with unique and persistent identifiers for publications, data sets, and research samples, ORCID is an essential underpinning needed to support interoperability between research systems.

  20. Airborne ocean water lidar (OWL) real time processor (RTP)

    Science.gov (United States)

    Hryszko, M.

    1995-03-01

    The Hyperflo Real Time Processor (RTP) was developed by Pacific-Sierra Research Corporation as a part of the Naval Air Warfare Center's Ocean Water Lidar (OWL) system. The RTP was used for real time support of open ocean field tests at Barbers Point, Hawaii, in March 1993 (EMERALD I field test), and Jacksonville, Florida, in July 1994 (EMERALD I field test). This report describes the system configuration, and accomplishments associated with the preparation and execution of these exercises. This document is intended to supplement the overall test reports and provide insight into the development and use of the PTP. A secondary objective is to provide basic information on the capabilities, versatility and expandability of the Hyperflo RTP for possible future projects. It is assumed herein that the reader has knowledge of the OWL system, field test operations, general lidar processing methods, and basic computer architecture.

  1. Mixed methods research.

    Science.gov (United States)

    Halcomb, Elizabeth; Hickman, Louise

    2015-04-08

    Mixed methods research involves the use of qualitative and quantitative data in a single research project. It represents an alternative methodological approach, combining qualitative and quantitative research approaches, which enables nurse researchers to explore complex phenomena in detail. This article provides a practical overview of mixed methods research and its application in nursing, to guide the novice researcher considering a mixed methods research project.

  2. Roundtable: Researching the Selfie

    National Research Council Canada - National Science Library

    Jonathan Schroeder

    2014-01-01

      This roundtable gathers researchers interested in the phenomenon of the "selfie" -- to explore current developments, research methods and interdisciplinary research into how consumer behavior, social...

  3. Design Research between Design and Research

    DEFF Research Database (Denmark)

    Steinø, Nicolai; Markussen, Thomas

    2011-01-01

    design strand have argued, that architecture and design research must follow an architecture and design methodology – designing – and be communicated by means of architecture and design media – images and artefacts. Essentially, this view sees no difference between architecture and design research......The discourse on architecture and design research in Denmark in the past thirty years has been stuck in a unproductive dichotomy between research through design on the one hand and a phantom image of academic and theoretical, word-based research on the other. Advocates of the research through...... and practice, as expressed in the notion of research as ‘artistic innovation work’. On the other hand, the pressure to expand research in architecture and design has seen a movement towards adopting traditional research paradigms from the technical and social sciences and humanities. For many architects...

  4. Design Research between Design and Research

    DEFF Research Database (Denmark)

    Steinø, Nicolai; Markussen, Thomas

    2011-01-01

    The discourse on architecture and design research in Denmark in the past thirty years has been stuck in a unproductive dichotomy between research through design on the one hand and a phantom image of academic and theoretical, word-based research on the other. Advocates of the research through...... design strand have argued, that architecture and design research must follow an architecture and design methodology – designing – and be communicated by means of architecture and design media – images and artefacts. Essentially, this view sees no difference between architecture and design research...... and practice, as expressed in the notion of research as ‘artistic innovation work’. On the other hand, the pressure to expand research in architecture and design has seen a movement towards adopting traditional research paradigms from the technical and social sciences and humanities. For many architects...

  5. Design Research between Design and Research

    DEFF Research Database (Denmark)

    Steinø, Nicolai; Markussen, Thomas

    The discourse on architecture and design research in Denmark in the past thirty years has been stuck in a unproductive dichotomy between research through design on the one hand and a phantom image of academic and theoretical, word-based research on the other. Advocates of the research through...... design strand have argued, that architecture and design research must follow an architecture and design methodology – designing – and be communicated by means of architecture and design media – images and artefacts. Essentially, this view sees no difference between architecture and design research...... and practice, as expressed in the notion of research as ‘artistic innovation work’. On the other hand, the pressure to expand research in architecture and design has seen a movement towards adopting traditional research paradigms from the technical and social sciences and humanities. For many architects...

  6. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Health NIH Research Matters NIH Record Research & Training Medical Research Initiatives Science Highlights Science Education Research in ... can. The genetic methods for all sorts of medical genetic disorders have been refined over the past ...

  7. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Research Trials and You Talking to Your Doctor Science Education Resources Community Resources Clear Health A–Z ... Matters NIH Record Research & Training Medical Research Initiatives Science Highlights Science Education Research in NIH Labs & Clinics ...

  8. The modern research environment

    DEFF Research Database (Denmark)

    Topsøe, Flemming

    1993-01-01

    Information Technology, research environment, structured documents, networked information retrieval......Information Technology, research environment, structured documents, networked information retrieval...

  9. From Action Research to Practice Research

    Directory of Open Access Journals (Sweden)

    Goran Goldkuhl

    2012-04-01

    Full Text Available Action research (AR has gained more acceptance as an approach to qualitative research in information systems (IS. The complexities of organisational and technical change makes this approach a suitable one in IS research. There are, however, still some controversies and confusions about the relation between “action” and “research”. The many types of AR and similar approaches (not labelled as AR that have emerged demands further conceptual clarification of AR. A conceptual inquiry of AR, presented in the paper, has led to the identification of several unresolved issues concerning intervention research like AR. An alternative research approach is presented: practice research. This research approach is well founded in pragmatism and it builds on the two premises: 1 to contribute to general practice through abstract and useful knowledge and 2 to study the empirical field as interconnected practices. Several important concepts of practice research are described as: local practice contribution vs. general practice contribution; theorizing vs. situational inquiry. Practice research is seen as a broader notion encompassing AR and other research approaches as e.g. design research and evaluation research. Two case examples of practice research are briefly presented and compared: one AR-based study in the social welfare sector and one evaluation study of a taxation e-service.

  10. The School Research Lead

    Science.gov (United States)

    Bennett, Tom

    2015-01-01

    The researchED movement has generated a new debate about the role of research in schools. Of course there have always been teachers interested in undertaking research and applying the research findings of others. However, involvement in research has tended to be the personal enthusiasm of the individual teacher rather than a coordinated whole…

  11. Research Training in Biopsychosocial Breast Cancer Research

    National Research Council Canada - National Science Library

    Andrykowski, Michael

    2004-01-01

    ...) in biopsychosocial breast cancer (BC) research. During the 5-year project period, 6 predoctoral and 2 postdoctoral trainees were appointed to the training program and received training in biopsychosocial breast cancer research...

  12. ARTICLE Nutritional Intervention Research Unit, Medical Research ...

    African Journals Online (AJOL)

    ARTICLE. Nutritional Intervention Research Unit, Medical Research Council of South Africa, Tygerberg,. W Cape ... determined by questionnaire; anunquantified food frequency questionnaire was used to determine usual food intake. Biochemical ..... complementary foods, incorrect preparation of formula feeds, and frequent ...

  13. Case Study Research Methodology in Nursing Research.

    Science.gov (United States)

    Cope, Diane G

    2015-11-01

    Through data collection methods using a holistic approach that focuses on variables in a natural setting, qualitative research methods seek to understand participants' perceptions and interpretations. Common qualitative research methods include ethnography, phenomenology, grounded theory, and historic research. Another type of methodology that has a similar qualitative approach is case study research, which seeks to understand a phenomenon or case from multiple perspectives within a given real-world context.

  14. Research award: Collaborative Adaptation Research Initiative in ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2017-09-06

    Sep 6, 2017 ... We offer a number of research awards providing a unique opportunity to enhance research skills and gain a fresh perspective on crucial development issues. These one‐year, paid, in‐house programs of training and mentorship allow award holders to pursue their research goals and work in one of IDRC's ...

  15. Teacher as Researcher: Teaching as Lived Research

    Science.gov (United States)

    Binder, Marni

    2012-01-01

    Teacher inquiry can shape empirical inquiries by nonpracticing researchers, by allowing them to draw on the practical knowledge of those in the classroom. This recognition challenged the author to question what legitimized her role as a teacher-researcher and ask how she could have felt empowered as a researcher without higher education. In this…

  16. Research through design & research through education

    NARCIS (Netherlands)

    Eggink, Wouter; Mulder-Nijkamp, Maaike

    2016-01-01

    The very definition of a university is a place where research and education are intertwined. When there is no research, a university will look like a place for vocational training, and when there are no students to teach, the university is no more than a research institution. This convention of

  17. Design Research between Design and Research

    DEFF Research Database (Denmark)

    Steinø, Nicolai; Markussen, Thomas

    2011-01-01

    The discourse on architecture and design research in Denmark in the past thirty years has been stuck in a unproductive dichotomy between research through design on the one hand and a phantom image of academic and theoretical, word-based research on the other. Advocates of the research through des......, the main difference between design and research is in the object; design creates artefacts (physical or abstract) and research creates knowledge.......The discourse on architecture and design research in Denmark in the past thirty years has been stuck in a unproductive dichotomy between research through design on the one hand and a phantom image of academic and theoretical, word-based research on the other. Advocates of the research through...... design strand have argued, that architecture and design research must follow an architecture and design methodology – designing – and be communicated by means of architecture and design media – images and artefacts. Essentially, this view sees no difference between architecture and design research...

  18. Mixed methods research in music therapy research.

    Science.gov (United States)

    Bradt, Joke; Burns, Debra S; Creswell, John W

    2013-01-01

    Music therapists have an ethical and professional responsibility to provide the highest quality care possible to their patients. Much of the time, high quality care is guided by evidence-based practice standards that integrate the most current, available research in making decisions. Accordingly, music therapists need research that integrates multiple ways of knowing and forms of evidence. Mixed methods research holds great promise for facilitating such integration. At this time, there have not been any methodological articles published on mixed methods research in music therapy. The purpose of this article is to introduce mixed methods research as an approach to address research questions relevant to music therapy practice. This article describes the core characteristics of mixed methods research, considers paradigmatic issues related to this research approach, articulates major challenges in conducting mixed methods research, illustrates four basic designs, and provides criteria for evaluating the quality of mixed methods articles using examples of mixed methods research from the music therapy literature. Mixed methods research offers unique opportunities for strengthening the evidence base in music therapy. Recommendations are provided to ensure rigorous implementation of this research approach.

  19. Research Supervision: The Research Management Matrix

    Science.gov (United States)

    Maxwell, T. W.; Smyth, Robyn

    2010-01-01

    We briefly make a case for re-conceptualising research project supervision/advising as the consideration of three inter-related areas: the learning and teaching process; developing the student; and producing the research project/outcome as a social practice. We use this as our theoretical base for an heuristic tool, "the research management…

  20. Governing Knowledge: Research Steering and Research Quality

    Science.gov (United States)

    Ozga, Jenny

    2008-01-01

    This article argues that the "quality" debate in education research is not so much about quality as about creating the conditions in which research and knowledge production in the field of education can be managed and steered. The criticisms of research in education have destabilised the field and promoted its closer dependence on and…

  1. Rocky Mountain Research Station: 2010 Research Accomplishments

    Science.gov (United States)

    Rick Fletcher

    2010-01-01

    The Rocky Mountain Research Station is one of seven regional units that make up the USDA Forest Service Research and Development organization ­ the most extensive natural resources research organization in the world. We maintain 12 field laboratories throughout a 12-state territory encompassing the Great Basin, Southwest, Rocky Mountains, and parts of the Great Plains...

  2. Research Leadership as Entrepreneurial Organizing for Research

    Science.gov (United States)

    Hansson, Finn; Monsted, Mette

    2008-01-01

    The paper discusses research leadership in public universities under change and the role of entrepreneurial strategies in research. Research leadership function today in situations where the New Public Management movement one the one hand have introduced management by accountability and control in the university while on the other hand open…

  3. Research Methodology in Global Strategy Research

    DEFF Research Database (Denmark)

    Cuervo-Cazurra, Alvaro; Mudambi, Ram; Pedersen, Torben

    2017-01-01

    We review advances in research methodology used in global strategy research and provide suggestions on how researchers can improve their analyses and arguments. Methodological advances in the extraction of information, such as computer-aided text analysis, and in the analysis of datasets, such as......We review advances in research methodology used in global strategy research and provide suggestions on how researchers can improve their analyses and arguments. Methodological advances in the extraction of information, such as computer-aided text analysis, and in the analysis of datasets......, such as differences-in-differences and propensity score matching, have helped deal with challenges (e.g., endogeneity and causality) that bedeviled earlier studies and resulted in conflicting findings. These methodological advances need to be considered as tools that complement theoretical arguments and well......-explained logics and mechanisms so that researchers can provide better and more relevant recommendations to managers designing the global strategies of their organizations....

  4. Researcher-researched relationship in qualitative research: Shifts in positions and researcher vulnerability.

    Science.gov (United States)

    Råheim, Målfrid; Magnussen, Liv Heide; Sekse, Ragnhild Johanne Tveit; Lunde, Åshild; Jacobsen, Torild; Blystad, Astrid

    2016-01-01

    The researcher role is highly debated in qualitative research. This article concerns the researcher-researched relationship. A group of health science researchers anchored in various qualitative research traditions gathered in reflective group discussions over a period of two years. Efforts to establish an anti-authoritarian relationship between researcher and researched, negotiation of who actually "rules" the research agenda, and experiences of shifts in "inferior" and "superior" knowledge positions emerged as central and intertwined themes throughout the discussions. The dual role as both insider and outsider, characteristic of qualitative approaches, seemed to lead to power relations and researcher vulnerability which manifested in tangible ways. Shifting positions and vulnerability surfaced in various ways in the projects. They nonetheless indicated a number of similar experiences which can shed light on the researcher-researched relationship. These issues could benefit from further discussion in the qualitative health research literature.

  5. Ethical suicide research: a survey of researchers.

    Science.gov (United States)

    Lakeman, Richard; Fitzgerald, Mary

    2009-02-01

    Research is needed to better understand and respond effectively to people who are suicidal. Involving people who are suicidal in research poses some ethical and pragmatic problems. The ethical problems and difficulties in obtaining approval to involve people who are suicidal in research has contributed to the current paucity of research that explores the suicidal experience. To explore some of these problems, a web-based survey of suicide researchers was undertaken. Researchers identified from published reports were contacted by email and invited to participate in a web-based survey. Researchers were asked to describe any problems they encountered, how ethical problems were negotiated or resolved, and any advice received from human research ethics committees. The main problems identified were accessing the population, maintaining confidentiality, the extent of care owed by the researcher to participants, and the facilitation of support to participants. As with clinical practice, ethical research involving people who are suicidal involves a process of sensitive engagement, and careful consideration and remediation of risk.

  6. From Research Assistant to Professional Research Assistance: Research Consulting as a Form of Research Practice

    Directory of Open Access Journals (Sweden)

    Dawn E. Pollon

    2013-01-01

    Full Text Available Research assistantships have long been viewed as an extension of the formal education process, a form of apprenticeship, and a pathway into the professional practice of research in institutional settings. However, there are other contexts in which researchers practice research. This self-study documents the formative role research assistantships played in the authors’ development as professional research consultants. Four professional research consultants who held research assistant positions during their master’s and doctoral studies describe the contributions of their research assistantship experiences to the advancement of their knowledge, skills, and passion for research and subsequently to their career decisions. Professional research consulting is identified as a natural extension of research assistant roles and a potential career path. The article enhances current understandings about the ways research assistantships contribute to the development of researchers, and specifically to the development of professional research consultants. The analysis will be of interest to students contemplating entering into research assistantships, current research assistants, current research assistant supervisors, academic staff looking to improve their research productivity, and department chairs.

  7. Research Training in Biopsychosocial Breast Cancer Research

    National Research Council Canada - National Science Library

    Andrykowski, Michael

    2002-01-01

    This report summarizes activities and accomplishments during the third year of a four year training program in biopsychosocial breast cancer (BC) research. Three trainees (1 postdoctoral; 2 predoctoral...

  8. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Info Lines Health Services Locator HealthCare.gov NIH Clinical Research Trials and You Talking to Your Doctor ... Labs & Clinics Training Opportunities Library Resources Research Resources Clinical Research Resources Safety, Regulation and Guidance More » Quick ...

  9. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Science Highlights Science Education Research in NIH Labs & Clinics Training Opportunities Library Resources Research Resources Clinical Research ... speech-language-pathology programs in universities and speech clinics in places like England, Brazil and other places. ...

  10. National Privacy Research Strategy

    Data.gov (United States)

    Networking and Information Technology Research and Development, Executive Office of the President — On July 1, NITRD released the National Privacy Research Strategy. Research agencies across government participated in the development of the strategy, reviewing...

  11. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Trials and You Talking to Your Doctor Science Education Resources Community Resources Clear Health A–Z Publications ... Research & Training Medical Research Initiatives Science Highlights Science Education Research in NIH Labs & Clinics Training Opportunities Library ...

  12. Research on Catalysis.

    Science.gov (United States)

    Bartholomew, Calvin H.; Hecker, William C.

    1984-01-01

    The objectives and philosophy of the Catalysis Laboratory at Brigham Young University are discussed. Also discusses recent and current research activities at the laboratory as well as educational opportunities, research facilities, and sources of research support. (JN)

  13. Children's Environmental Health Research

    Science.gov (United States)

    Conducted in-house, with our federal partners like NIH’s National Institute of Environmental Health Services (NIEHS), and by external researchers through a research grants program administered through the agency’s Office of Research & Development.

  14. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Quick Links NIH News in Health NIH Research Matters NIH Record Research & Training Medical Research Initiatives Science ... work with speech therapy organizations in the United States that have provided a steady flow of subjects ...

  15. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Toolkits Grants & Funding Grants Home Page Funding Forms Library Due Dates How to Apply About Grants Policy & ... Education Research in NIH Labs & Clinics Training Opportunities Library Resources Research Resources Clinical Research Resources Safety, Regulation ...

  16. Researcher Story: Stuttering

    Science.gov (United States)

    ... Have a Question In the News Researcher Story: Stuttering In a 2010 movie, The King’s Speech, many ... effects of the disorder. How Do Researchers Study Stuttering? Video of How Do Researchers Study Stuttering? A ...

  17. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Have a Question In the News Researcher Story: Stuttering In a 2010 movie, The King’s Speech, many ... effects of the disorder. How Do Researchers Study Stuttering? Video of How Do Researchers Study Stuttering? A ...

  18. Inclusive research: new challenges

    OpenAIRE

    Nind, Melanie

    2015-01-01

    This presentation will engage participants in a critical examination of inclusive research. First, I will define inclusive research and identify the social contextual elements that have shaped it as an overarching concept in the move towards the democratisation of research. Next, I will explore quality and ethics in inclusive research, building on research conducted in the field of learning disability and using examples from a range of applied social research contexts. Finally I will invite u...

  19. Research at KT 2002

    DEFF Research Database (Denmark)

    Glarborg, Peter; Hassager, Ole; Jonsson, Gunnar Eigil

    2002-01-01

    The objective of this document is to give the reader a brief overview of current research directions at the department of chemical engineering. The main research topics are classified in terms of priority research areas and are achievements in these areas are highlighted through publications made...... by the 6 main research groups. It should be noted, however, the listed research topics are not the only areas of research and that there are also other interdisciplinary research groups and individual faculty members with their specific research area....

  20. Fuel safety research 1999

    Energy Technology Data Exchange (ETDEWEB)

    Uetsuka, Hiroshi (ed.) [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2000-07-01

    In April 1999, the Fuel Safety Research Laboratory was newly established as a result of reorganization of the Nuclear Safety Research Center, JAERI. The laboratory was organized by combining three laboratories, the Reactivity Accident Laboratory, the Fuel Reliability Laboratory, and a part of the Sever Accident Research Laboratory. Consequently, the Fuel Safety Research Laboratory is now in charge of all the fuel safety research in JAERI. Various types of experimental and analytical researches are conducted in the laboratory by using the unique facilities such as the Nuclear Safety Research Reactor (NSRR), the Japan Material Testing Reactor (JMTR), the Japan Research Reactor 3 (JRR-3) and hot cells in JAERI. The laboratory consists of five research groups corresponding to each research fields. They are; (a) Research group of fuel behavior under the reactivity initiated accident conditions (RIA group). (b) Research group of fuel behavior under the loss-of-coolant accident conditions (LOCA group). (c) Research group of fuel behavior under the normal operation conditions (JMTR/BOCA group). (d) Research group of fuel behavior analysis (FEMAXI group). (e) Research group of FP release/transport behavior from irradiated fuel (VEGA group). This report summarizes the outline of research activities and major outcomes of the research executed in 1999 in the Fuel Safety Research Laboratory. (author)

  1. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Apply About Grants Policy & Compliance Grants News/Blog Contracts Loan Repayment More ... & Training Medical Research Initiatives Science Highlights Science Education Research ...

  2. NuSTAR Hard X-ray Observations of the Energetic Millisecond Pulsars PSR B1821-24, PSR B1937+21, and PSR J0218+4232

    Science.gov (United States)

    Gotthelf, Eric V.; Bogdanov, Slavko

    2017-08-01

    We present NuSTAR hard X-ray timing and spectroscopy of the three exceptionally energetic rotation-powered millisecond pulsars PSRs B1821-24, B1937+21, and J0218+4232. By correcting for frequency and phase drifts of the NuSTAR on-board clock we are able to recover the intrinsic hard X-ray pulse profiles of all three pulsars with a resolution down to pulsars, respectively. We conduct phase-resolved spectroscopy in the 0.5 - 79 keV range for all three objects, obtaining the best yet measurements of the broad-band spectral shape and high-energy pulsed emission to date. We find extensions of the same power-law continua seen at lower energies, with no conclusive evidence for a spectral turnover or break. Extrapolation of the X-ray power-law spectrum to higher energies reveals that a turnover in the 100 keV to 100 MeV range is required to accommodate the high energy gamma-ray emission observed with Fermi LAT, similar to the broad-band spectral energy distribution observed for the Crab pulsar.

  3. Cancer Research UK | IDRC - International Development Research ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Cancer Research UK. https://www.cancerresearchuk.org/ · What we do · Funding · Resources · About IDRC. Knowledge. Innovation. Solutions. Careers · Contact Us · Site map. Sign up now for IDRC news and views sent directly to your inbox each month. Subscribe · Copyright · Open access policy · Privacy policy · Research ...

  4. Research essentials. How to critique quantitative research.

    Science.gov (United States)

    Clarke, Sharon; Collier, Sue

    2015-11-01

    QUANTITATIVE RESEARCH is a systematic approach to investigating numerical data and involves measuring or counting attributes, that is quantities. Through a process of transforming information that is collected or observed, the researcher can often describes a situation or event, answering the 'what' and 'how many' questions about a situation ( Parahoo 2014 ).

  5. Researching as an Enactivist Mathematics Education Researcher

    Science.gov (United States)

    Brown, Laurinda

    2015-01-01

    This paper focusses on how researching is done through reflections about, or at a meta-level to, the practice over time of an enactivist mathematics education researcher. How are the key concepts of enactivist theory ("ZDM Mathematics Education," doi: 10.1007/s11858-014-0634-7, 2015) applied? This paper begins by giving an…

  6. Research Award: Advisory Committee on Research Ethics

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    respects persons, animals and the environment. • demonstrates appropriate measures to protect the welfare of participants. • promotes well‐being. • avoids causing harm. • treats people fairly, equitably, and with dignity. IDRC's Advisory Committee on Research Ethics (ACRE) promotes the principles of ethical research at.

  7. FNS Research Corner: Summary of Research

    Science.gov (United States)

    Berman, Danielle; Burdg, Jinee

    2017-01-01

    The FNS Research Corner provides a continuing series to summarize recently completed and current research conducted by the U.S. Department of Agriculture's Food and Nutrition Service (FNS) in the area of child nutrition. For further information, contact the Office of Policy Support (OPS) at (703) 305-2117. Links to published studies and reports as…

  8. Research Award: Global Health Research Iniave

    International Development Research Centre (IDRC) Digital Library (Canada)

    Corey Piccioni

    2013-08-07

    Deadline: August 7, 2013. Please note that all applicafions must be sent electronically. IDRC is one of the world's leaders in generang new knowledge to meet global challenges. We offer a number of research awards providing a unique opportunity to enhance research skills and gain a fresh perspecve on crucial.

  9. Research Update: Research on Adventure (Risk) Education.

    Science.gov (United States)

    Attarian, Aram

    1991-01-01

    Reviews recent research on outdoor adventure (risk) recreation which exposes participants to real or perceived danger. The research examines several professional issues (leadership certification, leadership style, program outcomes, and retention and turnover of program staff), and discusses social, individual, and therapeutic benefits. (SM)

  10. Researchers' intuitions about power in psychological research

    NARCIS (Netherlands)

    Bakker, M.; Hartgerink, C. H. J.; Wicherts, J. M.; Van Der Maas, H. L. J.

    2016-01-01

    Many psychology studies are statistically underpowered. In part, this may be because many researchers rely on intuition, rules of thumb, and prior practice (along with practical considerations) to determine the number of subjects to test. In Study 1, we surveyed 291 published research psychologists

  11. Teaching Qualitative Research to Practitioner-Researchers

    Science.gov (United States)

    Cox, Rebecca D.

    2012-01-01

    Practitioner-researchers are well-positioned to apply qualitative methods to the study of significant problems of educational practice. However, while learning the skills of qualitative inquiry, practitioners may be compelled by forces outside of qualitative research classrooms to think quantitatively. In this article, the author considers two…

  12. Research Librarian | IDRC - International Development Research ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Job Summary The Research Librarian is a key member of a team responsible for the delivery of comprehensive research information services which contribute strategic value to the work of clients. Intermediated search services at the expert level, the development and delivery of orientations, training/coaching, ...

  13. National Environmental Research Parks

    Energy Technology Data Exchange (ETDEWEB)

    1994-07-01

    The National Environmental Research Parks are outdoor laboratories that provide opportunities for environmental studies on protected lands that act as buffers around Department of Energy (DOE) facilities. The research parks are used to evaluate the environmental consequences of energy use and development as well as the strategies to mitigate these effects. They are also used to demonstrate possible environmental and land-use options. The seven parks are: Fermilab National Environmental Research Park; Hanford National Environmental Research Park; Idaho National Environmental Research Park; Los Alamos National Environmental Research Park; Nevada National Environmental Research Park; Oak Ridge National Environmental Research Park; and Savannah River National Environmental Research Park. This document gives an overview of the events that led to the creation of the research parks. Its main purpose is to summarize key points about each park, including ecological research, geological characteristics, facilities, and available databases.

  14. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Education Research in NIH Labs & Clinics Training Opportunities Library Resources Research Resources Clinical Research Resources Safety, Regulation and Guidance More » Quick Links PubMed Stem Cell Information OppNet NIDB NIH Blueprint for Neuroscience Research Institutes ...

  15. Observational Research: Formalized Curiosity

    Science.gov (United States)

    Skaggs, Paul

    2004-01-01

    Design research is a valuable tool to help the designer understand the problem that he/she needs to solve. The purpose of design research is to help state or understand the problems better, which will lead to better solutions. Observational research is a design research method for helping the designer understand and define the problem.…

  16. IDRC Doctoral Research Awards

    International Development Research Centre (IDRC) Digital Library (Canada)

    test

    1) Research Proposal. Proposals must be 20-25 pages, double-spaced, in 12 point font (not inclusive of bibliography) and address ALL of the following items, presented in separate headings: • Abstract of research proposal. (max. 250 words). • Literature Review. • Research question(s). • Research objective. • Methodology.

  17. Research in Mathematics Education

    Science.gov (United States)

    Schoenfeld, Alan H.

    2016-01-01

    As one of the three Rs, "'rithmetic" has always been central to education and education research. By virtue of that centrality, research in mathematics education has often reflected and at times led trends in education research. This chapter provides some deep background on epistemological and other issues that shape current research,…

  18. NFSMI Research Summary

    Science.gov (United States)

    Nettles, Mary Frances

    2014-01-01

    The NFSMI Research Summary is a continuing series of summaries reporting recently completed research and research-based resources funded by the National Food Service Management Institute. The following research studies are summarized in this article: (1) Succession Planning for Management Level Staff in School Nutrition Programs; (2)…

  19. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Media Resources Media Contacts Images and B-roll Events Social Media More » Quick Links NIH News in Health NIH Research Matters NIH Record Research & Training Medical Research Initiatives Science Highlights Science Education Research in NIH Labs & Clinics ...

  20. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Resources Media Contacts Images and B-roll Events Social Media More » Quick Links NIH News in Health NIH Research Matters NIH Record Research & Training Medical Research Initiatives Science Highlights Science Education Research in NIH Labs & Clinics ...

  1. Research Methods Tutorial

    Science.gov (United States)

    Aguilera, Frank J.

    2015-01-01

    A guiding principle for conducting research in technology, science, and engineering, leading to innovation is based on our use of research methodology (both qualitative and quantitative). A brief review of research methodology will be presented with an overview of NASA process in developing aeronautics technologies and other things to consider in research including what is innovation.

  2. Research Methods Tutorial

    Science.gov (United States)

    Aguilera, Frank J.

    2015-01-01

    A guiding principle for conducting research in technology, science, and engineering, leading to innovation is based on our use of research methodology (both qualitative and qualitative). A brief review of research methodology will be presented with an overview of NASA process in developing aeronautics technologies and other things to consider in research including what is innovation.

  3. Teaching to Enhance Research

    Science.gov (United States)

    Harland, Tony

    2016-01-01

    In this paper, I present a conceptual argument for "teaching-led research" in which university lecturers construct courses that directly and positively influence their research, while at the same time, safeguard and enhance the student experience. A research-pedagogy for higher education considers the link between teaching and research,…

  4. Case study research.

    Science.gov (United States)

    Taylor, Ruth; Thomas-Gregory, Annette

    2015-06-10

    This article describes case study research for nursing and healthcare practice. Case study research offers the researcher an approach by which a phenomenon can be investigated from multiple perspectives within a bounded context, allowing the researcher to provide a 'thick' description of the phenomenon. Although case study research is a flexible approach for the investigation of complex nursing and healthcare issues, it has methodological challenges, often associated with the multiple methods used in individual studies. These are explored through examples of case study research carried out in practice and education settings. An overview of what constitutes 'good' case study research is proposed.

  5. Qualitative Research in Psychology

    Directory of Open Access Journals (Sweden)

    Fattah Hanurawan

    2013-02-01

    Full Text Available Abstract:Qualitative  research  is  a  research  method    studying  subjective meaning of participant’s world about  an object researched. Steps of qualitative research  in  psychology  are:  researchers  select  research  topic,  researchers formulate  research  questions,  researchers  design  the  study,  researchers  collect data, researchers analyses  data,  researchers  generate  findings,  researchers validate findings, and researchers write research report. Some of the qualitative research  designs  are  grounded  research,  phenomenology  research,  case  study research,  and  ethnography  research.  In  some  situations,  researchers  often  meet questions  that  reach  beyond  the  prescription  of  the  APA  ethical  guidelines concerning  human  participants.  Researchers  of  qualitative  research  in psychology  can  generalize  their  research  findings  to  other  people,  times,  or treatments  to  the  degree  to  which  they  are  similar to  other  people,  times,  or treatments in the original research (naturalistic generalization. There are some strategies  for  expanding  qualitative  research  as  a research  approach  so  the methodology  can  be  accepted  as  one  significant  method  in  understanding psychological phenomena. Keywords:qualitative research, psychology.

  6. Improving University Research Value

    Directory of Open Access Journals (Sweden)

    Kelley O’Reilly

    2012-07-01

    Full Text Available This article investigates the current data management practices of university researchers at an Intermountain West land-grant research university in the United States. Key findings suggest that researchers are primarily focused on the collection and housing of research data. However, additional research value exists within the other life cycle stages for research data—specifically in the stages of delivery and maintenance. These stages are where most new demands and requirements exist for data management plans and policies that are conditional for external grant funding; therefore, these findings expose a “gap” in current research practice. These findings should be of interest to academics and practitioners alike as findings highlight key management gaps in the life cycle of research data. This study also suggests a course of action for academic institutions to coalesce campus-wide assets to assist researchers in improving research value.

  7. Rigour in quantitative research.

    Science.gov (United States)

    Claydon, Leica Sarah

    2015-07-22

    This article which forms part of the research series addresses scientific rigour in quantitative research. It explores the basis and use of quantitative research and the nature of scientific rigour. It examines how the reader may determine whether quantitative research results are accurate, the questions that should be asked to determine accuracy and the checklists that may be used in this process. Quantitative research has advantages in nursing, since it can provide numerical data to help answer questions encountered in everyday practice.

  8. Qualitative Research Process

    OpenAIRE

    Dewan Mahboob HOSSAIN

    2011-01-01

    This article provides with an overview of the qualitative research methods. Over last few decades, qualitative research is getting very popular in the fields of business, sociology, psychology and others. This article, in its introduction, gives a general idea about the qualitative research. Then it discusses the main differences between qualitative and quantitative research methods. The article also discusses about the ethical issues important for qualitative research. Lastly it discusses ab...

  9. Research Training in Biopsychosocial Breast Cancer Research

    National Research Council Canada - National Science Library

    Andrykowski, Michael

    2001-01-01

    This report summarizes activities and accomplishments during the second year of a 4 year training program in biopsychosocial breast cancer research. Three new trainees: (1) postdoctoral; and (2) predoctoral...

  10. Research by design - a research strategy

    DEFF Research Database (Denmark)

    Hauberg, Jørgen

    2011-01-01

    Abstract The idea of an expressive component in research is important to the architectural industry. The expressive element - the possibility of expressing the qualitative aspects of the world and adding something new to the existing through experiments and proposals - is characteristic for the f...... the work with form and space – drawings, models and completed works. Probably all good design is informed by some kind of researchresearch based design. But can research arise from design?......Abstract The idea of an expressive component in research is important to the architectural industry. The expressive element - the possibility of expressing the qualitative aspects of the world and adding something new to the existing through experiments and proposals - is characteristic...... for the field. All research environments, in the science tradition and in the humanities, have their characteristics. On the one hand, they live up to certain common scientific and methodological criteria - originality and transparency - on the other hand they have different practices, using different methods...

  11. Research by Design - a research strategy

    DEFF Research Database (Denmark)

    Hauberg, Jørgen

    2011-01-01

    Abstract The idea of an expressive component in research is important to the architectural industry. The expressive element - the possibility of expressing the qualitative aspects of the world and adding something new to the existing through experiments and proposals - is characteristic for the f...... is through work with form and space – drawings, models and completed works. Probably all good design is informed by some kind of researchresearch-based design. But can research arise from design?......Abstract The idea of an expressive component in research is important to the architectural industry. The expressive element - the possibility of expressing the qualitative aspects of the world and adding something new to the existing through experiments and proposals - is characteristic...... for the field. All research environments, in the science tradition and in the humanities, have their characteristics. On the one hand, they live up to certain common scientific and methodological criteria - originality and transparency – and on the other hand, they have different practices, using different...

  12. Research ethics committees: agents of research policy?

    Directory of Open Access Journals (Sweden)

    Hemminki Elina

    2005-10-01

    Full Text Available Abstract The purpose of this commentary is to describe the unintended effects ethics committees may have on research and to analyse the regulatory and administrative problems of clinical trials. Discussion The Finnish law makes an arbitrary distinction between medical research and other health research, and the European Union's directive for good clinical trials further differentiates drug trials. The starting point of current rules is that clinical trials are lesser in the interest of patients and society than routine health care. However, commercial interests are not considered unethical. The contrasting procedures in research and normal health care may tempt physicians to continue introducing innovations into practice by relying on unsystematic and uncontrolled observations. Tedious and bureaucratic rules may lead to the disappearance of trials initiated by researchers. Trying to accommodate the special legislative requirements for new drug trials into more complex interventions may result in poor designs with unreliable results and increased costs. Meanwhile, current legal requirements may undermine the morale of ethics committee members. Conclusion The aims and the quality of the work of ethics committees should be evaluated, and a reformulation of the EU directive on good clinical trials is needed. Ethical judgement should consider the specific circumstance of each trial, and ethics committees should not foster poor research for legal reasons.

  13. Responsible conduct of research

    CERN Document Server

    Shamoo, Adil E

    2015-01-01

    Since the early 2000s, the field of Responsible Conduct of Research has become widely recognized as essential to scientific education, investigation, and training. At present, research institutions with public funding are expected to have some minimal training and education in RCR for their graduate students, fellows and trainees. These institutions also are expected to have a system in place for investigating and reporting misconduct in research or violations of regulations in research with human subjects, or in their applications to federal agencies for funding. Public scrutiny of the conduct of scientific researchers remains high. Media reports of misconduct scandals, biased research, violations of human research ethics rules, and moral controversies in research occur on a weekly basis. Since the 2009 publication of the 2nd edition of Shamoo and Resnik's Responsible Conduct of Research, there has been a vast expansion in the information, knowledge, methods, and diagnosis of problems related to RCR and the ...

  14. Fuel safety research 2001

    Energy Technology Data Exchange (ETDEWEB)

    Uetsuka, Hiroshi (ed.) [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2002-11-01

    The Fuel Safety Research Laboratory is in charge of research activity which covers almost research items related to fuel safety of water reactor in JAERI. Various types of experimental and analytical researches are being conducted by using some unique facilities such as the Nuclear Safety Research Reactor (NSRR), the Japan Material Testing Reactor (JMTR), the Japan Research Reactor 3 (JRR-3) and the Reactor Fuel Examination Facility (RFEF) of JAERI. The research to confirm the safety of high burn-up fuel and MOX fuel under accident conditions is the most important item among them. The laboratory consists of following five research groups corresponding to each research fields; Research group of fuel behavior under the reactivity initiated accident conditions (RIA group). Research group of fuel behavior under the loss-of-coolant accident conditions (LOCA group). Research group of fuel behavior under the normal operation conditions (JMTR/BOCA group). Research group of fuel behavior analysis (FEMAXI group). Research group of radionuclides release and transport behavior from irradiated fuel under severe accident conditions (VEGA group). The research conducted in the year 2001 produced many important data and information. They are, for example, the fuel behavior data under BWR power oscillation conditions in the NSRR, the data on failure-bearing capability of hydrided cladding under LOCA conditions and the FP release data at very high temperature in steam which simulate the reactor core condition during severe accidents. This report summarizes the outline of research activities and major outcomes of the research executed in 2001 in the Fuel Safety Research Laboratory. (author)

  15. Executable research compendia in geoscience research infrastructures

    Science.gov (United States)

    Nüst, Daniel

    2017-04-01

    From generation through analysis and collaboration to communication, scientific research requires the right tools. Scientists create their own software using third party libraries and platforms. Cloud computing, Open Science, public data infrastructures, and Open Source enable scientists with unprecedented opportunites, nowadays often in a field "Computational X" (e.g. computational seismology) or X-informatics (e.g. geoinformatics) [0]. This increases complexity and generates more innovation, e.g. Environmental Research Infrastructures (environmental RIs [1]). Researchers in Computational X write their software relying on both source code (e.g. from https://github.com) and binary libraries (e.g. from package managers such as APT, https://wiki.debian.org/Apt, or CRAN, https://cran.r-project.org/). They download data from domain specific (cf. https://re3data.org) or generic (e.g. https://zenodo.org) data repositories, and deploy computations remotely (e.g. European Open Science Cloud). The results themselves are archived, given persistent identifiers, connected to other works (e.g. using https://orcid.org/), and listed in metadata catalogues. A single researcher, intentionally or not, interacts with all sub-systems of RIs: data acquisition, data access, data processing, data curation, and community support [3]. To preserve computational research [3] proposes the Executable Research Compendium (ERC), a container format closing the gap of dependency preservation by encapsulating the runtime environment. ERCs and RIs can be integrated for different uses: (i) Coherence: ERC services validate completeness, integrity and results (ii) Metadata: ERCs connect the different parts of a piece of research and faciliate discovery (iii) Exchange and Preservation: ERC as usable building blocks are the shared and archived entity (iv) Self-consistency: ERCs remove dependence on ephemeral sources (v) Execution: ERC services create and execute a packaged analysis but integrate with

  16. Consumer Behavior Research Methods

    DEFF Research Database (Denmark)

    Chrysochou, Polymeros

    2017-01-01

    emphasizes the discussion of primary research methods. Based on the nature of the data primary research methods are further distinguished into qualitative and quantitative. The chapter describes the most important and popular qualitative and quantitative methods. It concludes with an overall evaluation......This chapter starts by distinguishing consumer behavior research methods based on the type of data used, being either secondary or primary. Most consumer behavior research studies phenomena that require researchers to enter the field and collect data on their own, and therefore the chapter...... of the methods and how to improve quality in consumer behavior research methods....

  17. Advancing Ethical Neuroscience Research.

    Science.gov (United States)

    Borah, B Rashmi; Strand, Nicolle K; Chillag, Kata L

    2016-12-01

    As neuroscience research advances, researchers, clinicians, and other stakeholders will face a host of ethical challenges. The Presidential Commission for the Study of Bioethical Issues (Bioethics Commission) has published two reports that provide recommendations on how to advance research endeavors ethically. The commission addressed, among other issues, how to prioritize different types of neuroscience research and how to include research participants who have impaired consent capacity. The Bioethics Commission's recommendations provide a foundation for ethical guidelines as neuroscience research advances and progresses. © 2016 American Medical Association. All Rights Reserved.

  18. Economics of fusion research

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    1977-10-15

    This report provides the results of a study of methods of economic analysis applied to the evaluation of fusion research. The study recognizes that a hierarchy of economic analyses of research programs exists: standard benefit-cost analysis, expected value of R and D information, and expected utility analysis. It is shown that standard benefit-cost analysis, as commonly applied to research programs, is inadequate for the evaluation of a high technology research effort such as fusion research. A methodology for performing an expected value analysis is developed and demonstrated and an overview of an approach to perform an expected utility analysis of fusion research is presented. In addition, a potential benefit of fusion research, not previously identified, is discussed and rough estimates of its magnitude are presented. This benefit deals with the effect of a fusion research program on optimal fossil fuel consumption patterns. The results of this study indicate that it is both appropriate and possible to perform an expected value analysis of fusion research in order to assess the economics of a fusion research program. The results indicate further that the major area of benefits of fusion research is likely due to the impact of a fusion research program on optimal fossil fuel consumption patterns and it is recommended that this benefit be included in future assessments of fusion research economics.

  19. [Discussion paper participation research].

    Science.gov (United States)

    Farin, Erik

    2012-12-01

    This contribution introduces the "Diskussionspapier Teilhabeforschung" (discussion paper participation research) of the German Association for Rehabilitation (DVfR) and German Society for Rehabilitation Science (DGRW). The aim of this paper is to more clearly define current scientific research activity on the subject of participation and the significance of interdisciplinary participation research. The authors emphasise the desirability of a stronger scientific basis for instruments designed to improve the participation of disabled individuals. The paper is meant to be understood as an initial basis for the discussion about participation research development, and the authors are open to suggestions and elaboration.Participation research is understood in this discussion paper as an interdisciplinary research field with 7 goals and characteristics: 1. focussing on participation and self-determination; 2. contextual approach (taking environmental and personal factors into consideration that affect participation); 3. the participation of disabled persons in participation research; 4. interdisciplinary cooperation; 5. involving organisations and institutions whose approaches to participation research overlap; 6. referring to social and healthcare policies; 7. national and international orientations.The authors discuss the rationale behind increasing the support for participation research and theoretical models thereof. Fundamental concepts with high relevance to participation research include the biopsychosocial model of the International Classification of Functionality, Disability and Health (ICF), the inclusion concept, empowerment concept, and capabilities concept. The authors conclude their paper with recommendations for strengthening the research funding for participation research, and specify concrete steps toward greater participation research. © Georg Thieme Verlag KG Stuttgart · New York.

  20. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... research volunteers. If you stutter or have a family member who stutters, you could be eligible to ... Researchers Study Stuttering? A large portion of the family clustering of stuttering is explained by genes and ...

  1. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... at the NIH, is studying stuttering with the participation of research volunteers. If you stutter or have ... to participate in Dr. Drayna’s clinical research trial. Participation involves providing a small blood sample and a ...

  2. Photochemistry research at NREL

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, C.E.; Carlson, C.E. [National Renewable Energy Laboratory, Golden, CO (United States)

    1996-09-01

    Photochemistry research team at NREL conducts research and development work in all R&D areas, basic, applied, demonstration and transfer to commercialization. Basic research includes core PCO R&D and catalysts work as well as conducting research into new photochemistry areas such as photoinduced adsorption and high temperature solar PCO. Applied research work consists of remediation of chloroethylenes in gas phase, gas phase solar photoreactor development, and application research including indoor air quality, hybrid biological/PCO processes and more. We are demonstrating the PCO treatment technology in the gas phase with SEMATECH through CRADA work and remediation of organics in aqueous phase through the Solarchem Environmental Systems. We are working with IT through a CRADA to transfer the PCO gas phase remediation technology to IT to commercialize this promising -technology. Photochemistry research conducted at NREL spans the R&D spectrum from basic research through technology demonstration with the goal of technology commercialization.

  3. Lymphatic Education & Research Network

    Science.gov (United States)

    Lymphatic Education & Research Network Donate Now Become a Supporting Member X Living with LYMPHEDEMA AND Lymphatic Disease FAQs About ... December 8, 2017 11.08.2017 The Lymphatic Education & Research Network… Read More > ASRM LE&RN Combined ...

  4. Environmental Toxicology Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Fully-equipped facilities for environmental toxicology researchThe Environmental Toxicology Research Facility (ETRF) located in Vicksburg, MS provides over 8,200 ft...

  5. Ice Engineering Research Area

    Data.gov (United States)

    Federal Laboratory Consortium — Refrigerated Physical Modeling of Waterways in a Controlled EnvironmentThe Research Area in the Ice Engineering Facility at the Cold Regions Research and Engineering...

  6. Basic Research Firing Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Basic Research Firing Facility is an indoor ballistic test facility that has recently transitioned from a customer-based facility to a dedicated basic research...

  7. NIH Research to Results

    Science.gov (United States)

    ... Current Issue Past Issues Special Section: Focus on Communication NIH Research to Results Past Issues / Fall 2008 ... is unable to replace hair cells, our hearing declines as they are lost. Researchers at Oregon Health & ...

  8. Fanconi Anemia Research Fund

    Science.gov (United States)

    ... Support Publications Fundraising News What is the Fanconi Anemia Research Fund? Fanconi anemia is an inherited disease that can lead to ... population. Lynn and Dave Frohnmayer started the Fanconi Anemia Research Fund, in 1989 to find effective treatments ...

  9. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Educational Resources Glossary of Common Terms If You Have a Question In the News Researcher Story: Stuttering ... participation of research volunteers. If you stutter or have a family member who stutters, you could be ...

  10. Research Reports: Marijuana

    Science.gov (United States)

    ... Publications » Research Reports » Marijuana » Letter From the Director Marijuana Email Facebook Twitter Letter From the Director Photo ... February 12, 2018. press ctrl+c to copy Marijuana and Cannabinoids: A Neuroscience Research Summit March 22- ...

  11. Nordic research in ophthalmology

    DEFF Research Database (Denmark)

    Stefánsson, Einar; Zetterström, Charlotta; Ehlers, Niels

    2003-01-01

    Ophthalmology, eye research, cornea, catarcat, paediatric ophthalmology, glaucoma, diabetic eye disease, age-related macular degeneration, ophthalmic oncology......Ophthalmology, eye research, cornea, catarcat, paediatric ophthalmology, glaucoma, diabetic eye disease, age-related macular degeneration, ophthalmic oncology...

  12. Epidemiology & Genomics Research Program

    Science.gov (United States)

    The Epidemiology and Genomics Research Program, in the National Cancer Institute's Division of Cancer Control and Population Sciences, funds research in human populations to understand the determinants of cancer occurrence and outcomes.

  13. Research Programs & Initiatives

    Science.gov (United States)

    CGH develops international initiatives and collaborates with other NCI divisions, NCI-designated Cancer Centers, and other countries to support cancer control planning, encourage capacity building, and support cancer research and research networks.

  14. Researcher Interview: Tom Hudson

    Science.gov (United States)

    Tom Hudson, M.D., President and Scientific Director of the Ontario Institute for Cancer Research, describes the International Cancer Genome Consortium (ICGC), which brings together cancer genomic data and research from across the world.

  15. Aquatic Research Laboratory (ARL)

    Data.gov (United States)

    Federal Laboratory Consortium — Columbia River and groundwater well water sources are delivered to the Aquatic Research Laboratory (ARL), where these resources are used to conduct research on fish...

  16. Newport Research Station

    Data.gov (United States)

    Federal Laboratory Consortium — The Newport Research Station is the Center's only ocean-port research facility. This station is located at Oregon State University's Hatfield Marine Science Center,...

  17. Flight Research Building (Hangar)

    Data.gov (United States)

    Federal Laboratory Consortium — The NASA Glenn Flight Research Building is located at the NASA Glenn Research Center with aircraft access to Cleveland Hopkins International Airport. The facility is...

  18. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Health Information Health Info Lines Health Services Locator HealthCare.gov NIH Clinical Research Trials and You Talking ... Neuroscience Research Institutes at NIH List of Institutes, Centers & Offices NIH Office of the Director Directors of ...

  19. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Highlights Science Education Research in NIH Labs & Clinics Training Opportunities Library Resources Research ... Who We Are What We Do Jobs at NIH Visitor Information Frequently Asked Questions Contact ...

  20. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Library Resources Research Resources Clinical Research Resources Safety, Regulation and Guidance More » Quick Links PubMed Stem Cell ... the family clustering of stuttering is explained by genes and not by environment. So, the question is, ...

  1. Mukilteo Research Station

    Data.gov (United States)

    Federal Laboratory Consortium — Research at the Mukilteo Research Station focuses on understanding the life cycle of marine species and the impacts of ecosystem stressors on anadromous and marine...

  2. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... the News Researcher Story: Stuttering In a 2010 movie, The King’s Speech, many learned for the first ... and Answers about NIDCD Stuttering Research The Long Road to Discovery: Stuttering Genes Turn Up in the ...

  3. The Singapore research story

    CERN Document Server

    Teck Seng, Low; Thampuran, Raj

    2016-01-01

    Ever since Singapore became independent in 1965, its leaders have invested tremendous efforts and resources to develop its economy in order to create jobs for its people and to support national development. This book describes the challenging journey of Singapore in developing a knowledge-based economy driven by research and innovation and the roles played by research institutes, universities, research manpower and appropriate collaboration between research institutes and industry. The book traces the foundations of Singapore's research story from the time of its independence in 1965 to the present day. Through interviews with the key players and research into the records, the establishment of the key institutes and the roles of a global cast of researchers, scientists and engineers in setting up the R&D infrastructure are outlined. The impact that the concerted efforts of the last 25 years to build up a credible and world-class research capability in Singapore is discussed, as are the tremendous challeng...

  4. DCB - Tumor Metastasis Research

    Science.gov (United States)

    Tumor metastasis research examines the mechanisms that allow cancer cells to leave the primary tumor and spread to another part of the body. Learn about recent tumor metastasis research studies supported by the Division of Cancer Biology.

  5. Mesothelioma Applied Research Foundation

    Science.gov (United States)

    Mesothelioma Foundation Experts Can Answer Your Questions! The Mesothelioma Applied Research Foundation's team of experts is available ... up for our e-newsletter . Our Impact Against Mesothelioma 9.8 Million in research funded 600 People ...

  6. Cereal Crops Research Unit

    Data.gov (United States)

    Federal Laboratory Consortium — The mission of the Cereal Crops Research Unit is to 1) conduct basic research to identify and understand the biological processes affecting the growth, development...

  7. Researching Identity and Interculturality

    DEFF Research Database (Denmark)

    Lønsmann, Dorte

    2016-01-01

    Review of: Researching Identity and Interculturality / by F. Dervin and K. Risager (eds.). Routledge 2015, 245 pp.......Review of: Researching Identity and Interculturality / by F. Dervin and K. Risager (eds.). Routledge 2015, 245 pp....

  8. Scoliosis Research Society

    Science.gov (United States)

    Scoliosis Research Society Close Menu Member Login Become a Member Home Find a Specialist | Calendar Contact | Donate ... a Member Find a Specialist Calendar Contact Donate Scoliosis Research Society Dedicated to the optimal care of ...

  9. Introspection from research trainnig and educational research

    Directory of Open Access Journals (Sweden)

    María Camila Clavijo Gallego

    2014-07-01

    Full Text Available In the preschool teacher degree of the Corporacion Autonoma Universitaria del Cauca, it is revealed a series of tensions caused by the research training process and its influence in qualifying for the degree –among them the difficulties on dealing with the educational research process related to the alma mater established norms, are highlighted. This paper addresses to such tensions from a perspective that respects, above all, the senses and the feelings of a group of ten female teacher trainees who tackle, criticize and propose –from interviews and open and enjoyable writings– the compilation of experiences that provide a series of possibilities that positively affect the research process and the contribution to the development, meaning and sense of being preschool teachers.

  10. Research in cardiovascular care

    DEFF Research Database (Denmark)

    Jaarsma, Tiny; Deaton, Christi; Fitzsimmons, Donna

    2014-01-01

    with the increasing opportunities and challenges in multidisciplinary research, the Science Committee of the Council on Cardiovascular Nursing and Allied Professionals (CCNAP) recognised the need for a position statement to guide researchers, policymakers and funding bodies to contribute to the advancement...... of the body of knowledge that is needed to further improve cardiovascular care. In this paper, knowledge gaps in current research related to cardiovascular patient care are identified, upcoming challenges are explored and recommendations for future research are given....

  11. European DHC Research Issues

    Energy Technology Data Exchange (ETDEWEB)

    Wiltshire, Robin; Williams, Jonathan (Building Research Establishment, BRE, Bucknalls Lane, Watford (United Kingdom)); Werner, Sven (Halmstad University, School of Business and Engineering, Halmstad (Sweden))

    2008-09-15

    Euroheat and Power is now working towards a European Technology Platform for District Heating and Cooling. In response to this important European DHC research initiative, a preliminary detailed list of research issues within 18 dimensions was elaborated and communicated to more than 100 people in February 2008. After additions and comments received, an updated list of research issues was again distributed in July 2008. This paper contains the current list of suggested research issues

  12. What Is Qualitative Research?

    Science.gov (United States)

    Otani, Takashi

    2017-01-01

    The article is an in-depth explanation of qualitative research, an approach increasingly prevalent among today's research communities. After discussing its present spread within the health sciences, the author addresses: 1. Its definition. 2. Its characteristics, as well as its theoretical and procedural background. 3. Its procedures. 4. Differences between qualitative and quantitative approaches. 5. Mixed methods incorporating quantitative research. And in conclusion: 6. The importance of establishing an epistemological perspective in qualitative research.

  13. Can research be visual?

    DEFF Research Database (Denmark)

    Martiny, Kristian Moltke

    2014-01-01

    Short film interviews with for instance researchers Birger Lindberg Møller and Andreas Roepstorff and film directors Phie Ambo, Janus Metz and Joshua Oppenheimer, about the collaboration between documentary and research: http://vimeo.com/99909839......Short film interviews with for instance researchers Birger Lindberg Møller and Andreas Roepstorff and film directors Phie Ambo, Janus Metz and Joshua Oppenheimer, about the collaboration between documentary and research: http://vimeo.com/99909839...

  14. The qualitative research proposal

    OpenAIRE

    Klopper, Hester

    2008-01-01

    Qualitative research in the health sciences has had to overcome many prejudices and a number of misunderstandings, but today qualitative research is as acceptable as quantitative research designs and is widely funded and published. Writing the proposal of a qualitative study, however, can be a challenging feat, due to the emergent nature of the qualitative research design and the description of the methodology as a process. Even today, many sub-standard proposals at post-graduate evaluation c...

  15. Getting involved in research.

    Science.gov (United States)

    Banner, Davina; Grant, Lyle G

    2011-01-01

    The need for quality nursing research to promote evidence-based practice and optimize patient care is well recognized. This is particularly pertinent in cardiovascular nursing, where cardiovascular disease continues to be the leading cause of morbidity and mortality worldwide (World Health Organization, 2007). Across the spectrum of academic, clinical, and health care administration nursing roles, research remains fundamental to bridging theory, practice, and education (LoBiondo-Wood, Haber, Cameron, & Singh, 2009). Despite recognition of the importance of nursing research, the gap between research and practice continues to be an ongoing issue (Funk, Tornquist, & Champagne, 1995; Pettengill, Gillies, & Clark, 1994; Rizzuto, Bostrom, Suterm, & Chenitz, 1994; Rolfe, 1998). Nurses are appropriately situated to contribute to research that improves clinical outcomes and health service delivery. However, the majority of nurses in clinical practice do not have a significant research component structured into their nursing role. In this research column, the authors outline the importance of nurses being engaged in research and present some different levels of involvement that nurses may assume. A continuum of nursing research involvement includes asking researchable questions, being a savvy consumer of research evidence, finding your own level of research involvement, and aspiring to lead.

  16. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Health Services Locator HealthCare.gov NIH Clinical Research Trials and You Talking to Your Doctor Science Education ... are here Home » Health Information » NIH Clinical Research Trials and You NIH Clinical Research Trials and You ...

  17. Communicating research results

    Science.gov (United States)

    Jan Fryk

    1999-01-01

    A research finding is of little value until it is known and applied. Hence) communication of results should be regarded as a natural, integrated part of research) and thus addressed in the research plans from the very beginning. A clearly defined information strategy and operational goals for information activities are needed for successful communication. For maximum...

  18. Language Teaching and Research.

    Science.gov (United States)

    Nunan, David

    A discussion of the relationship between language teaching and research begins by defining research as a systematic process of inquiry in which the researcher poses a question or questions, collects relevant data, analyzes and interprets it, and makes the results accessible to others. It looks at the simplistic but persistent distinction between…

  19. Transforming Assessment Research

    DEFF Research Database (Denmark)

    Nielsen, Jan Alexis; Dolin, Jens; Tidemand, Sofie

    2018-01-01

    This chapter will identify and outline current gaps in research into assessment practice and tie the results of the ASSIST-ME project onto this outline. In this way, the chapter will present concrete research vistas that are still needed in international assessment research. The chapter concludes...

  20. Research and Communication Officer

    International Development Research Centre (IDRC) Digital Library (Canada)

    Under the supervision of the Regional Director in Dakar, Senegal, and working closely with the Director of Communications in Ottawa, the Research and Communication Officer seeks to ensure visibility for. IDRC and its research partners and to disseminate the results of research financed by the Centre. He/ she participates ...

  1. Writing a Research Paper

    Science.gov (United States)

    Mikk, Jaan

    2006-01-01

    The value of research and the career of a university lecturer depend heavily on the success in publishing scientific papers. This article reviews the guidelines for writing and submitting research papers. The three most important success criteria in publishing are as follows: the paper describes a good research, it is written according to the…

  2. Researching entrepreneurship with autoethnography

    DEFF Research Database (Denmark)

    Gottlieb, Frederik

    2015-01-01

    making process, thus directly affecting the context. The paper concludes that deep involvement when researching entrepreneurial contexts is important to explore new themes, however in these processes the researchers involvement will inevitably affect the the context and those being researched as well....

  3. Music and Visual Research

    DEFF Research Database (Denmark)

    Jensen, Julie Borup

    2017-01-01

    The paper explores the potential of video ethnography concerning educational research on music as contributing to an inclusive learning environment in elementary school (research objective). In music education research, the use of visual data provided by video seems to be a relevant choice...

  4. Highland Medical Research Journal

    African Journals Online (AJOL)

    The aim of the Highland Medical Research Journal is to publish scientific research in various fields of medical science and to communicate such research findings to the larger world community. It aims to promote cooperation and understanding amoungst workers in various fields of medical science.

  5. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... the American Recovery Act News & Events News Releases Digital Media Kits Media Resources Media Contacts Images and B-roll Events Social Media More » Quick Links NIH News in Health NIH Research Matters NIH Record Research & Training Medical Research Initiatives Science Highlights Science ...

  6. Multimedia Teacher Research

    Science.gov (United States)

    Leaman, Heather; DiLucchio, Connie

    2015-01-01

    In this qualitative study, two teacher educators and course instructors in a Masters of Education (M.Ed.) program explored beginning teacher researchers' use of multimedia to support action research. Fifty-eight teachers (36 in spring 2010 and 22 in spring 2011) completed teacher research as the capstone in their M.Ed. program. Teachers utilized…

  7. Action research: Scandinavian Experiences

    DEFF Research Database (Denmark)

    Rasmussen, Lauge Baungaard

    2004-01-01

    The article focus on paradigms, methods and ethics of action research in the Scandinavian countries. The special features of the action research paradigm is identified. A historical overview follows of some main action research projects in Norway, Sweden and Denmark. The tendency towards upsclae...

  8. Research Priorities for Endometriosis.

    Science.gov (United States)

    Rogers, Peter A W; Adamson, G David; Al-Jefout, Moamar; Becker, Christian M; D'Hooghe, Thomas M; Dunselman, Gerard A J; Fazleabas, Asgerally; Giudice, Linda C; Horne, Andrew W; Hull, M Louise; Hummelshoj, Lone; Missmer, Stacey A; Montgomery, Grant W; Stratton, Pamela; Taylor, Robert N; Rombauts, Luk; Saunders, Philippa T; Vincent, Katy; Zondervan, Krina T

    2017-02-01

    The 3rd International Consensus Workshop on Research Priorities in Endometriosis was held in São Paulo on May 4, 2014, following the 12th World Congress on Endometriosis. The workshop was attended by 60 participants from 19 countries and was divided into 5 main sessions covering pathogenesis/pathophysiology, symptoms, diagnosis/classification/prognosis, disease/symptom management, and research policy. This research priorities consensus statement builds on earlier efforts to develop research directions for endometriosis. Of the 56 research recommendations from the 2011 meeting in Montpellier, a total of 41 remained unchanged, 13 were updated, and 2 were deemed to be completed. Fifty-three new research recommendations were made at the 2014 meeting in Sao Paulo, which in addition to the 13 updated recommendations resulted in a total of 66 new recommendations for research. The research recommendations published herein, as well as those from the 2 previous papers from international consensus workshops, are an attempt to promote high-quality research in endometriosis by identifying and agreeing on key issues that require investigation. New areas included in the 2014 recommendations include infertility, patient stratification, and research in emerging nations, in addition to an increased focus on translational research. A revised and updated set of research priorities that builds on this document will be developed at the 13th World Congress on Endometriosis to be held on May 17-20, 2017, in Vancouver, British Columbia, Canada.

  9. Action and Interactiv research

    DEFF Research Database (Denmark)

    Nielsen, Kurt Aagaard; Svensson, Lennart

    The text is written as a first version of editors introduction to a book about action research/interactive research in Nordic countries. You can read abouttrends and contradictions in the history of action research.The authors question the trends and demands a more explicit critical approach...

  10. 'The research compass'

    DEFF Research Database (Denmark)

    Ringsted, Charlotte; Hodges, Brian; Scherpbier, Albert

    2011-01-01

    This AMEE Guide offers an introduction to research in medical education. It is intended for those who are contemplating conducting research in medical education but are new to the field. The Guide is structured around the process of transforming ideas and problems into researchable questions, cho...

  11. Music Researchers' Musical Engagement

    Science.gov (United States)

    Wollner, Clemens; Ginsborg, Jane; Williamon, Aaron

    2011-01-01

    There is an increasing awareness of the importance of reflexivity across various disciplines, which encourages researchers to scrutinize their research perspectives. In order to contextualize and reflect upon research in music, this study explores the musical background, current level of musical engagement and the listening habits of music…

  12. Research Methods in Education

    Science.gov (United States)

    Check, Joseph; Schutt, Russell K.

    2011-01-01

    "Research Methods in Education" introduces research methods as an integrated set of techniques for investigating questions about the educational world. This lively, innovative text helps students connect technique and substance, appreciate the value of both qualitative and quantitative methodologies, and make ethical research decisions.…

  13. Research Application Paper

    Science.gov (United States)

    Baskas, Richard S.

    2011-01-01

    The purpose of this study is to compare and contrast two types of scholarly article designs, quantitative and qualitative, as to how two research designs can be similar and different, and how the authors conduct their research and present their results. When researching and analyzing two scholarly articles of different design types, it is…

  14. Stimulating translational research

    DEFF Research Database (Denmark)

    Bentires-Alj, Mohamed; Rajan, Abinaya; van Harten, Wim

    2015-01-01

    Translational research leaves no-one indifferent and everyone expects a particular benefit. We as EU-LIFE (www.eu-life.eu), an alliance of 13 research institutes in European life sciences, would like to share our experience in an attempt to identify measures to promote translational research with...

  15. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... NIH Clinical Research Trials and You NIH Clinical Research Trials and You The Basics Finding a Clinical Trial List of Registries Personal Stories For Parents and Children For Health Care Providers For Researchers and Trial Sites Educational Resources Glossary of Common Terms If You Have ...

  16. Designing requirements engineering research

    NARCIS (Netherlands)

    Wieringa, Roelf J.; Heerkens, Johannes M.G.

    2007-01-01

    Engineering sciences study different topics than natural sciences, and utility is an essential factor in choosing engineering research problems. But despite these differences, research methods for the engineering sciences are no different than research methods for any other kind of science. At most

  17. Research in International Education

    Science.gov (United States)

    Dolby, Nadine; Rahman, Aliya

    2008-01-01

    Until recently, international education has existed at the margins of educational research. However, in the current context of globalization, international education has moved closer to the center of educational research throughout the world. In this article, the authors identify, describe, and analyze six distinct research approaches to…

  18. Design-based research

    NARCIS (Netherlands)

    Reeves, Thomas; McKenney, Susan

    2016-01-01

    Educational design research is a genre of research in which the iterative development of solutions to practical and complex educational problems provides the setting for scientific inquiry. The solutions can be educational products, processes, programs or policies. Educational design research not

  19. Doing Research with Teachers

    Science.gov (United States)

    Nussbaum, Luci

    2017-01-01

    Research in schools entails a journey of mutual recognition and trust between the researchers and the teaching staff, and a negotiation of give-and-take. The most effective reward for both parties is engaging in a mutually satisfying project in which both the researchers and the teachers occupy complementary spaces--rather than asymmetrical…

  20. Ecological Research Division, Marine Research Program

    Energy Technology Data Exchange (ETDEWEB)

    1980-05-01

    This report presents program summaries of the various projects sponsored during 1979 by the Marine Research Program of the Ecological Research Division. Program areas include the effects of petroleum hydrocarbons on the marine environment; a study of the baseline ecology of a proposed OTEC site near Puerto Rico; the environmental impact of offshore geothermal energy development; the movement of radionuclides through the marine environment; the environmental aspects of power plant cooling systems; and studies of the physical and biological oceangraphy of the continental shelves bordering the United States.

  1. Rich Design Research Space

    Directory of Open Access Journals (Sweden)

    Birger Sevaldson

    2008-10-01

    Full Text Available This paper introduces and discusses a Rich Research Space as an inclusive methodological framework and scaffold for research-by-design. The Rich Research Space especially addresses the issue of richness in design processes and design-led research. There is a general trend towards increased complexity in design processes, caused on one hand by the increasing depth and width in the use of design media and methods, and on the other hand by the increasing complexity and interdependency of society due to globalisation. These issues confront the designer-researcher with new challenges. This paper formulates a research strategy for research-by-design in fields that have a high degree of richness in the use of media, the amount of information, and the methods involved. The Rich Research Space concept proposed takes into account the physical, social, and cultural spaces, and the virtual and visual media spaces in which the research-by-design takes place. The concept takes the form of a specific integral approach to design, and a holistic theoretical mindset. It embraces many types of investigation, from analytical to intuitive. The Rich Research Space provides a flexible framework within which the complexity of research-by-design can be interrelated, discussed, and reflected upon. Potentially, it can create a more involved role for the designer-researcher, a role that allows contributions towards the resolution of ever more pressing issues in our society. This approach is currently one of a limited number of possible frameworks that the design professions can utilize in order to make a difference in a world of at times overwhelming complexity. The concept of the Rich Research Space is discussed with reference to an art installation called Barely.Keywords: Research by design, collaborative design, complexity, creativity, research methods.

  2. Action Research for Sustainability

    DEFF Research Database (Denmark)

    Egmose, Jonas

    to provide local citizens with a greater say in the future of urban sustainability research, this book shows how action research can make important methodological contributions to processes of social learning between citizens and scientists by enabling free spaces in peoples everyday life and within academia......How can action research further new research orientations towards sustainability? This book, empirically situated in the field of upstream public engagement, involving local residents, researchers and practitioners in bottom-up processes deliberating on urban sustainability, answers this question...

  3. Directions for further research

    DEFF Research Database (Denmark)

    Minsaas, Atle; Psaraftis, Harilaos N.

    2015-01-01

    Green transportation logistics is an area that combines the following: (a) it is relatively new in terms of research carried out thus far, (b) it has become increasingly important for both industry and society, and (c) it is rich in topics for further research, both basic and applied. In this final...... chapter of this book we discuss directions for further research in this area. We do so by taking stock of (1) related recommendations of project SuperGreen, and (2) related activities mainly in European research. Links between research and policy-making as two activities that should go hand in hand...

  4. Teaching and researching

    CERN Document Server

    Grabe, William

    2013-01-01

    Teaching and Researching Reading was first written to help language professionals understand the complex nature of reading. Now in a thoroughly updated and improved second edition, the book expands connections from research on reading to instructional practices and teacher-initiated action research. Offering an updated overview of reading theory, it summarises key ideas and issues in first and second language contexts.In addition to providing insightful research analyses, Grabe and Stoller offer practical advice for practitioners and researchers, including evidence-based teaching ideas and a m

  5. Towards programmatic design research

    Directory of Open Access Journals (Sweden)

    Jonas Löwgren

    2013-12-01

    Full Text Available The notion of design research entails research where design practice forms part of the knowledge production. Based on our characterization of the nature of design, we propose to conceptualize this kind of research as programmatic design research. Two ongoing PhD projects in interaction design are presented as examples of programmatic research processes, highlighting issues to do with the virtues and qualities of the processes, the interplay of optics and engagements in a hermeneutical dynamic, and the production of takeaways for the academic community.

  6. Overview of qualitative research.

    Science.gov (United States)

    Grossoehme, Daniel H

    2014-01-01

    Qualitative research methods are a robust tool for chaplaincy research questions. Similar to much of chaplaincy clinical care, qualitative research generally works with written texts, often transcriptions of individual interviews or focus group conversations and seeks to understand the meaning of experience in a study sample. This article describes three common methodologies: ethnography, grounded theory, and phenomenology. Issues to consider relating to the study sample, design, and analysis are discussed. Enhancing the validity of the data, as well reliability and ethical issues in qualitative research are described. Qualitative research is an accessible way for chaplains to contribute new knowledge about the sacred dimension of people's lived experience.

  7. Prostitution Research in Context

    DEFF Research Database (Denmark)

    -infected realm? These two questions are exactly what Spanger and Skilbrei aim to unpack in this unusual interdisciplinary methodology book, Prostitution Research in Context. The book offers contributions from a number of scholars who, based on their reflections on their own research practice and the existing...... knowledge field, discuss ongoing methodological issues and challenges representative of international research on sex for sale. Some chapters deal explicitly with methodological dilemmas in research; others thematise the encounter between prostitution research and general texts on epistemology. Other...

  8. Researching Postgraduate Educational Research in South Africa

    Science.gov (United States)

    Karlsson, J.; Balfour, R.; Moletsane, R.; Pillay, G.

    2009-01-01

    This article is about the national project to gather together information about postgraduate education research (PPER) in South Africa conducted over a ten-year period, namely 1995-2004, being the first decade in the democratic era for South Africa. The ideas informing the PPER Project are provided and the complex process of developing the PPER…

  9. Finnish bioenergy research programme

    Energy Technology Data Exchange (ETDEWEB)

    Asplund, D. [VTT Energy, Jyvaeskylae (Finland)

    1996-12-31

    Finland is a leading country in the use of biofuels and has excellent opportunities to increase the use of biofuels by up to 25-30 %. The Finnish Government has set an objective for the promotion of bioenergy. The aim is to increase the use of bioenergy by about 25 % from the present level by 2005, and the increment corresponds to 1.5 million tonnes of oil equivalent (toe) per year. The R and D work has been considered as an important factor to achieve this ambitious goal. Energy research was organised into a series of research programmes in 1988 in accordance with the proposal of Finnish Energy Research Committee. The object of the research programmes is to enhance research activities and to bundle individual projects together into larger research packages. The common target of the Finnish energy research programmes is to proceed from basic and applied research to product development and pilot operation, and after that to the first commercial applications, e.g. demonstrations. As the organisation of energy research to programmes has led to good results, the Finnish Ministry of Trade and Industry decided to go on with this practice by launching new six-year programmes in 1993-1998. One of these programmes is the Bioenergy Research Programme and the co-ordination of this programme is carried out by VTT Energy. Besides VTT Energy the Finnish Forest Research Institute, Work Efficiency Institute, Metsaeteho and University of Joensuu are participating in the programme 7 refs.

  10. Materials research at CMAM

    Science.gov (United States)

    Zucchiatti, Alessandro

    2013-07-01

    The Centro de Micro Analisis de Materiales (CMAM) is a research centre of the Universidad Autónoma de Madrid dedicated to the modification and analysis of materials using ion beam techniques. The infrastructure, based on a HVEE 5MV tandem accelerator, provided with a coaxial Cockcroft Walton charging system, is fully open to research groups of the UAM, to other public research institutions and to private enterprises. The CMAM research covers a few important lines such as advanced materials, surface science, biomedical materials, cultural heritage, materials for energy production. The Centre gives as well support to university teaching and technical training. A detail description of the research infrastructures and their use statistics will be given. Some of the main research results will be presented to show the progress of research in the Centre in the past few years and to motivate the strategic plans for the forthcoming.

  11. eParticipation Research

    DEFF Research Database (Denmark)

    Medaglia, Rony

    2012-01-01

    Research on the use of information technology to support democratic decision-making (eParticipation) is experiencing ongoing growth, stimulated by an increasing attention from both practitioner and research communities. This study provides the first longitudinal analysis of the development of the e......Participation field based on a shared framework, capturing the directions that the research field of eParticipation is taking in recent developments. Drawing on a literature search covering the period from April 2006 to March 2011, this study identifies, analyzes, and classifies 122 research articles within...... also suggests new analytical categories of research. Drawing on the analysis, inputs for a research agenda are suggested. These include the need to move beyond a technological perspective, encouraging the ongoing shift of research focus from government to citizens and other stakeholders, and the need...

  12. Materials research at CMAM

    Energy Technology Data Exchange (ETDEWEB)

    Zucchiatti, Alessandro [Centro de Micro Analisis de Materiales CMAM, Universidad Autonoma de Madrid, c/ Faraday 3, 28049 Madrid (Spain)

    2013-07-18

    The Centro de Micro Analisis de Materiales (CMAM) is a research centre of the Universidad Autonoma de Madrid dedicated to the modification and analysis of materials using ion beam techniques. The infrastructure, based on a HVEE 5MV tandem accelerator, provided with a coaxial Cockcroft Walton charging system, is fully open to research groups of the UAM, to other public research institutions and to private enterprises. The CMAM research covers a few important lines such as advanced materials, surface science, biomedical materials, cultural heritage, materials for energy production. The Centre gives as well support to university teaching and technical training. A detail description of the research infrastructures and their use statistics will be given. Some of the main research results will be presented to show the progress of research in the Centre in the past few years and to motivate the strategic plans for the forthcoming.

  13. Succeeding with interactive research

    DEFF Research Database (Denmark)

    Krogh, Andreas Hagedorn; Nielsen, Morten Velsing

    2017-01-01

    the capacity for critique and ensuring that scientific standards are met. Based on our own experience and theories of interactive governance, network management and collaborative leadership, as well as on existing methodological literature, we provide guidance and suggest concrete tools and methods......Increasingly, social science research is carried out in collaboration with partners outside universities, yet research methodology is lacking on how to manoeuvre in a terrain where multiple actors set expectations for research. This article conceptualizes interactive research as research...... with and about society, and provides a set of systematic reflections on how to manage opposing pressures, tensions and dilemmas in interactive research projects. We formulate and address three major interactive research management tasks: ensuring continual commitment from external stakeholders, maintaining...

  14. 'The research compass'

    DEFF Research Database (Denmark)

    Ringsted, Charlotte; Hodges, Brian; Scherpbier, Albert

    2011-01-01

    compass'. Core to the model is the conceptual, theoretical framework that is the key to any direction. The compass depicts four main categories of research approaches that can be applied when studying medical education phenomena, 'Explorative studies'; 'Experimental studies'; 'Observational studies......This AMEE Guide offers an introduction to research in medical education. It is intended for those who are contemplating conducting research in medical education but are new to the field. The Guide is structured around the process of transforming ideas and problems into researchable questions......, choosing a research approach that is appropriate to the purpose of the study and considering the individual researcher's preferences and the contextual possibilities and constraints. The first section of the Guide addresses the rationale for research in medical education and some of the challenges posed...

  15. Training research through EFL

    Directory of Open Access Journals (Sweden)

    Mardanshina Rimma M.

    2016-01-01

    Full Text Available In a globalized research market, developing students’ research skills by means of a foreign language is of particular importance. Students’ research work within the framework of the syllabus and extracurricular activities constitute the system of scientific work of students in a higher education institution. The potential of a foreign language in shaping the academic and research competence of students of Economics is revealed in the content and process aspects. Linguistics and economics as fields of scientific knowledge are reflected in the content aspect. Regarding the mode of training research, the emphasis is on reading strategies and activities aimed at fluent comprehension and handling professional and scientific information. Students’ scientific conference survey proves the potential of EFL in research activities and sheds the light on the new ways to develop research competence.

  16. Sustainable Consumption: Research Challenges

    DEFF Research Database (Denmark)

    Reisch, Lucia A.; Cohen, Maurie J.; Thøgersen, John

    The Board of the Swedish Foundation for Strategic Environmental Research (Mistra) decided in October 2015 that a proposal for a funding application call in the research area of “sustainable consumption” should be drawn up. According to the statutes of Mistra, research funded by the foundation...... for achieving industrial applications shall be taken advantage of.” The funding application call to be developed by Mistra is to be based on an analysis of the current state of the art of research and of society’s knowledge needs regarding sustainable consumption. Mistra commissioned a committee of four...... the orientation of a new research program to be used as draft text for the call for funding applications. The aim of this background report is hence to shed light on future research topics within sustainable consumption from a Swedish perspective. The research pro- moted should help to develop Sweden...

  17. Researcher Identities in Transition

    DEFF Research Database (Denmark)

    Castelló, Montserrat; Wisker, Gina; Kobayashi, Sofie

    Researchers are now embarked upon what we define as a ‘risk career’, rather than, as previously, a relatively more predictable academic career. In this changing context, traditional milestones that enabled early career researchers to build their identities are disappearing. Instead, what we define...... as other emergent ‘signals’, the latent or clear indications from institutions and academic communities regarding career directions and necessary professional skills and attitudes should be identified and interpreted for researchers to adequately develop their new identities. The aim of this paper...... is twofold: a) to present a comprehensive framework of the notion of researcher identity by means of analysing those spheres of activity related to researcher and career development; and b) to relate researcher identities to the experiences of early career researchers with issues concerning signals...

  18. Dynamic Research Sketching

    DEFF Research Database (Denmark)

    Markussen, Thomas; Bang, Anne Louise; Knutz, Eva

    2012-01-01

    that recognize the process of designing and making an artifact as a legitimate method of inquiry. However, even though this type of research is thus grounded in design practice there are many different ways in which the process of designing and making an artifact can be used as a method of inquiry in order......In this paper we offer a new explanatory tool, called ‘dynamic research sketching’ useful for mapping and understanding how research through design can be a vehicle for theory construction. ‘Research through design’ is often used as an all-inclusive umbrella term for research practices...... to explore a research question. Occasionally, the lack of a systematic methodology for research through design being able to make clarifications and distinctions between various methods has been pointed out. Yet, only few attempts have been made to compensate for this lack. In this paper, the aim is to make...

  19. Science Education Research vs. Physics Education Research: A Structural Comparison

    OpenAIRE

    Akarsu, Bayram

    2011-01-01

    The main goal of this article is to introduce physics education research (PER) to researchers in other fields. Topics include discussion of differences between science education research (SER) and physics education research (PER), physics educators, research design and methodology in physics education research and current research traditions and trends (e.g. current research ideas) within PER.

  20. Clinical Research Methodology 2: Observational Clinical Research.

    Science.gov (United States)

    Sessler, Daniel I; Imrey, Peter B

    2015-10-01

    Case-control and cohort studies are invaluable research tools and provide the strongest feasible research designs for addressing some questions. Case-control studies usually involve retrospective data collection. Cohort studies can involve retrospective, ambidirectional, or prospective data collection. Observational studies are subject to errors attributable to selection bias, confounding, measurement bias, and reverse causation-in addition to errors of chance. Confounding can be statistically controlled to the extent that potential factors are known and accurately measured, but, in practice, bias and unknown confounders usually remain additional potential sources of error, often of unknown magnitude and clinical impact. Causality-the most clinically useful relation between exposure and outcome-can rarely be definitively determined from observational studies because intentional, controlled manipulations of exposures are not involved. In this article, we review several types of observational clinical research: case series, comparative case-control and cohort studies, and hybrid designs in which case-control analyses are performed on selected members of cohorts. We also discuss the analytic issues that arise when groups to be compared in an observational study, such as patients receiving different therapies, are not comparable in other respects.

  1. Action Research for Sustainability

    DEFF Research Database (Denmark)

    Egmose, Jonas

    to renew itself without eroding its own foundation of existence, it argues that since sustainability cannot be invented but only supported (or eroded) by science, we need to reframe science in the role of sustaining sustain-ability. Through analyses of a three year action research programme, aiming...... to provide local citizens with a greater say in the future of urban sustainability research, this book shows how action research can make important methodological contributions to processes of social learning between citizens and scientists by enabling free spaces in peoples everyday life and within academia......How can action research further new research orientations towards sustainability? This book, empirically situated in the field of upstream public engagement, involving local residents, researchers and practitioners in bottom-up processes deliberating on urban sustainability, answers this question...

  2. Action Research for Sustainability

    DEFF Research Database (Denmark)

    Egmose, Jonas

    to provide local citizens with a greater say in the future of urban sustainability research, this book shows how action research can make important methodological contributions to processes of social learning between citizens and scientists by enabling free spaces in peoples everyday life and within academia...... to renew itself without eroding its own foundation of existence, it argues that since sustainability cannot be invented but only supported (or eroded) by science, we need to reframe science in the role of sustaining sustain-ability. Through analyses of a three year action research programme, aiming......How can action research further new research orientations towards sustainability? This book, empirically situated in the field of upstream public engagement, involving local residents, researchers and practitioners in bottom-up processes deliberating on urban sustainability, answers this question...

  3. Social Work Research

    DEFF Research Database (Denmark)

    Social work research has gathered a greater transparency and clarity of identity in North American and parts of Europe. Furthermore, the rapid emergence of social work research in other European countries, China, India, Japan and elsewhere in Asia and Pacific Rim countries, and gradually in South...... America, has created a need for a collection that can contribute to both shaping and making accessible key and sometimes hard-to-access sources. This four-volume collection answers this need, bringing together key literature in a single resource and structuring it into thematic volumes to enable clear...... understanding of the different aspects involved in the research. Volume One: Historical Trajectories, Purposes and Key Concepts Volume Two: Key Decisions about Research Strategy Volume Three: The Practice of Social Work Research Volume Four: The Contexts of Social Work Research...

  4. Kantian Research in Slovakia

    Directory of Open Access Journals (Sweden)

    L'umboír Belás

    2016-11-01

    Full Text Available The paper focuses on the state of the research on Kant’s philosophy in Slovakia, particularly at the University of Prešov. In the first part the authors describe the situation of Kantian research between the 1850s and 1963 as a period during which there was almost no interest in Kant and his philosophy in the region. The main part of the paper deals with the revival of Kantian philosophy, presented by a group of scholars approximately twenty years ago, that gave rise to a series of successful research projects on Kant supported by the Slovak Ministry of Education, Science, Research and Sport. The paper outlines the series of five successive research projects that have been realized since 2004 focusing mainly on Kant’s practical philosophy and its relevance for contemporary society. It summarizes the achievements based on the international cooperation in the research and describes the main events and publications realized so far.

  5. Reflecting Contemporary Design Research

    DEFF Research Database (Denmark)

    Engholm, Ida

    2017-01-01

    In recent years, design research has been the object of growing attention in universities and academies throughout the world. The present paper addresses the heterogeneous character of design research and the current need for reflection on the various approaches and interests. For this purpose......, the paper follows two steps. First, it proposes a categorization of the field in the form of a position model. The paper’s underlying assumption is that design research as a discipline exists in many different forms that cannot necessarily be brought together under one common academic research tradition......; instead it is necessary to attempt to define the field in order to initiate discussions about what constitutes the various research bases for design. Second, the paper discusses the implication for future design research when it is an interdisciplinary field that involves many disciplines, mindsets...

  6. Action Research for Democracy

    DEFF Research Database (Denmark)

    Contemporary society encounters profound economical, socio-ecological and political crises challenging the democratic foundation of our societies. This book addresses the potentials and challenges for Action Research supporting democratic alternatives. It offers a broad spectrum of examples from...... Scandinavian Action Research showing different openings towards democratic development. The book’s first part contributes with a wide range of examples such as Action Research in relation to the Triple Helix/Mode II contexts, to design as a democratic process, to renewal of welfare work and public institutions......, to innovation policies combining Action Research with gender science. In the second part of the book epistemological and ontological dimensions of Action Research are discussed addressing questions of validity criteria related to Action Research, the transformation of knowledge institutions and the specific...

  7. Space biology research development

    Science.gov (United States)

    Bonting, Sjoerd L.

    1993-01-01

    The purpose of the Search for Extraterrestrial Intelligence (SETI) Institute is to conduct and promote research related activities regarding the search for extraterrestrial life, particularly intelligent life. Such research encompasses the broad discipline of 'Life in the Universe', including all scientific and technological aspects of astronomy and the planetary sciences, chemical evolution, the origin of life, biological evolution, and cultural evolution. The primary purpose was to provide funding for the Principal Investigator to collaborate with the personnel of the SETI Institute and the NASA-Ames Research center in order to plan and develop space biology research on and in connection with Space Station Freedom; to promote cooperation with the international partners in the space station; to conduct a study on the use of biosensors in space biology research and life support system operation; and to promote space biology research through the initiation of an annual publication 'Advances in Space Biology and Medicine'.

  8. Reflexivity in qualitative research

    DEFF Research Database (Denmark)

    Evans, Adam Brian; Nistrup, Anne; Henderson, Hannah

    2018-01-01

    Kingdom. Reflexive practice in both studies was affected by researcher biographies and by study design. In Study 1, both researchers were reasonably detached from the study context, the theoretical framework was in place from the very beginning, and reflexive practice was embedded in the study design......There has been something of a “reflexive shift” in sociological research. Sociological researchers are increasingly encouraged to be “present” within their work, and to recognize their own role in structuring the entire research process. One way to achieve this is through engagement in reflexive...... practice, that is, to reflect on our own values, beliefs, and biographies. It can be difficult to know exactly how a researcher should engage in these practices, however. Here, we discuss our reflexive practice in two case studies, both which utilized the same figurational theoretical framework...

  9. Architectural Practice as Research

    DEFF Research Database (Denmark)

    Hougaard, Anna Katrine

    2015-01-01

    , qualitative and quantitative, scientific and artistic methods pollinate each other, and an attempt to set up a span for ‘research by design’ to unfold in, rather than a rigid definition. In mutual exploitation architectural writing, drawing and potentially the construction of objects with properties embodied......The paper discusses a kind of research which lies between ‘research by design’ and ‘artistic research’. The term ‘research by design’ is reconstructed to include artistic ways of working, and the paper is an exemplification of a research practice, which seeks to let subjective and objective...... in them, is the very research. This approach is framed by Deleuze’s reading of Bergson’s intuitive method and Peirce’s concept abduction, both methods which concern creative processes, material production and organisation, and the breakthrough of novelty....

  10. 2016 Research Final Presentation

    Energy Technology Data Exchange (ETDEWEB)

    Koskelo, EliseAnne Corinne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-16

    These are slides which show an example of research at Los Alamos National Laboratory done by E.C. Koskelo to show college professors in the hopes of earning a research position or fellowship position. In summary, this researcher developed a new in-situ technique for the inspection of additively manufactured parts, created an algorithm which can correct "skewed" scans of angular parts/taken at oblique angles, and used AWS to detect hidden defects and thickness changes in aerospace composites.

  11. Isotope research materials

    Energy Technology Data Exchange (ETDEWEB)

    Wilkinson, M. K.; Young, Jr, F. W.

    1977-10-01

    Preparation of research isotope materials is described. Topics covered include: separation of tritium from aqueous effluents by bipolar electrolysis; stable isotope targets and research materials; radioisotope targets and research materials; preparation of an 241Am metallurgical specimen; reactor dosimeters; ceramic and cermet development; fission-fragment-generating targets of 235UO2; and wire dosimeters for Westinghouse--Bettis. (GHT)

  12. Researching with undergraduate students

    DEFF Research Database (Denmark)

    Wulf-Andersen, Trine Østergaard; Mogensen, Kevin; Hjort-Madsen, Peder

    2013-01-01

    The article presents a particular case of undergraduate students working on subprojects within the framework of their supervisors' (the authors') research project during Autumn Semester 2012 and Spring Semester 2013. The article's purpose is to show that an institutionalized focus on students...... as "research learners" rather than merely curriculum learners proves productive for both research and teaching. We describe the specific university learning context and the particular organization of undergraduate students' supervision and assistantships. The case builds on and further enhances a well...

  13. 1996 Faculty Research Catalog

    OpenAIRE

    Rowe, Neil

    1996-01-01

    "I hope this catalog conveys the same feeling of excitement that we have when it comes to discussing our research projects. We believe our work is unique among computer science departments because of the uniqueness of NPS. Our emphasis on applied research, our excellent facilities and support, and the preparation of our people place us in an enviable position to be able to push technology faster than most civilian research departments. Our uniqueness has positioned us for rapid progress in a...

  14. Research posts for women

    Science.gov (United States)

    The National Science Foundation (NSF) is accepting proposals for its Visiting Professorships for Women (VPW) program. Under this program, female scientists and engineers who are experienced in independent research can undertake advanced research as visiting professors at universities or research institutions that have the necessary facilities. In addition to research, each visiting professor takes on lecturing, counseling, and “other interactive activities” intended to increase the visibility of female scientists at the host institution and to encourage other women to pursue careers in science and engineering, according to NSF.

  15. Interviewing like a researcher

    DEFF Research Database (Denmark)

    Evald, Majbritt Rostgaard; Freytag, Per Vagn; Nielsen, Suna Løwe

    2018-01-01

    The purpose of this chapter is to show the transformation that takes place when a ‘neutral’ research method is turned into a ‘paradigm-embedded’ research method. Because a paradigm consists of some ultimate presumptions (understood as philosophical hypothesis or normative theses), paradigms influ...... the foundation for a more nuanced understanding of how research methods in general can be used very differently depending on the paradigm researcher’s departure.......The purpose of this chapter is to show the transformation that takes place when a ‘neutral’ research method is turned into a ‘paradigm-embedded’ research method. Because a paradigm consists of some ultimate presumptions (understood as philosophical hypothesis or normative theses), paradigms...... influence the way in which researchers understand problems and how researchers look at existing and available sets of research methods and knowledge in general. The powers of paradigms thus are substantial and should be noted by researchers to provide context for their reflections. The paradigms we depart...

  16. HIV behavioral research online.

    Science.gov (United States)

    Chiasson, Mary Ann; Parsons, Jeffrey T; Tesoriero, James M; Carballo-Dieguez, Alex; Hirshfield, Sabina; Remien, Robert H

    2006-01-01

    Internet access has caused a global revolution in the way people of all ages and genders interact. Many have turned to the Internet to seek love, companionship, and sex, prompting researchers to move behavioral studies online. The sexual behavior of men who have sex with men (MSM) has been more closely studied than that of any other group online given the abundance of gay-oriented websites and concerns about increasing transmission of HIV and other sexually transmitted infections. Not only does the Internet provide a new medium for the conduct of behavioral research and for participant recruitment into an array of research studies, it has the as yet unrealized potential to reach huge numbers of MSM with innovative harm reduction and prevention messages tailored to individualized needs, interests, and risk behavior. Internet-based research on sexual behavior has many advantages in rapidity of recruitment of diverse samples which include individuals unreachable through conventional methods (i.e., non-gay identified and geographically and socially isolated MSM, etc.). Internet-based research also presents some new methodologic challenges in study design, participant recruitment, survey implementation, and interpretation of results. In addition, there are ethical issues unique to online research including difficulties in verifying informed consent, obstacles to surveying minors, and the ability to assure anonymity. This paper presents a review of Internet-based research on sexual behavior in MSM, a general discussion of the methodologic and ethical challenges of Internet-based research, and recommendations for future interdisciplinary research.

  17. Qualitative research methods

    National Research Council Canada - National Science Library

    Sofaer, Shoshanna

    2002-01-01

    The use of rigorous qualitative research methods can enhance the development of quality measures, the development and dissemination of comparative quality reports, as well as quality improvement efforts...

  18. Ecological Exposure Research: Water

    Science.gov (United States)

    Overview of ecological exposure water research, including invasive species, Functional Process Zones (FPZs), biomarkers, pharmaceuticals in water, headwater streams, DNA barcoding, wetland ecosystem services, and sediment remediation.

  19. Flexible Electronics Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Flexible Electronics Research Facility designs, synthesizes, tests, and fabricates materials and devices compatible with flexible substrates for Army information...

  20. Clinical research informatics

    CERN Document Server

    Richesson, Rachel L

    2012-01-01

    This book provides foundational coverage of key areas, concepts, constructs, and approaches of medical informatics as it applies to clinical research activities, in both current settings and in light of emerging policies. The field of clinical research is fully characterized (in terms of study design and overarching business processes), and there is emphasis on information management aspects and informatics implications (including needed activities) within various clinical research environments. The purpose of the book is to provide an overview of clinical research (types), activities, and are