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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdo, A.A.; /Naval Research Lab, Wash., D.C. /Federal City Coll.; Ackermann, M.

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 tomore » 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.« less

GLAST Science Across Wavelengths

NASA Astrophysics Data System (ADS)

Blandford, R. D.

2006-12-01

The GLAST satellites is almost guaranteed to revolutionize GeV gamma ray astronomy because of the great discoveries that are being made at hard X-ray energy by the Suzaku and Swift satellites and in the TeV range using the H.E.S.S. and Magic telescopes. Unidentified EGRET sources are likely to be identified and new and fainter sources will be found. Known classes of sources blazars, pulsars, gamma ray bursts, supernova remnants, binary X-ray sources and so on will be monitored in much greater detail. Finally, there is the need to limit or even detect dark matter through its annihilation signature. The science that will emerge from GLAST will be determined in large measure by the effort that is put into multiwavelength observing. This will require significant commitments of observing time for monitoring pulsar arrival times, measuring faint galaxy spectra, detecting GeV gamma rays gamma ray bursts and so on. In this talk I will attempt to summarize current thinking on the GLAST multi-wavelength observing program and propose some new approaches.

The Role of Beam Geometry in Population Statistics and Pulse Profiles of Radio and Gamma-ray Pulsars

NASA Technical Reports Server (NTRS)

Gonthier, Peter L.; VanGuilder, Robert; Harding, Alice K.

2004-01-01

We present results of a pulsar population synthesis study that incorporates a number of recent developments and some significant improvements over our previous study. We have included the results of the Parkes multi-beam pulsar survey in our select group of nine radio surveys, doubling our sample of radio pulsars. More realistic geometries for the radio and gamma-ray beams are included in our Monte Carlo computer code that simulates the characteristics of the Galactic population of radio and gamma-ray pulsars. We adopted with some modifications the radio beam geometry of Arzoumanian, Chernoff & Cordes (2002). For the gamma-ray beam, we have assumed the slot gap geometry described in the work of Muslimov & Harding (2003). To account for the shape of the distribution of radio pulsars in the P(dot) - P diagram, we continue to find that decay of the magnetic field on a timescale of 2.8 Myr is needed. With all nine surveys, our model predicts that EGRET should have seen 7 radio-quiet (below the sensitivity of these radio surveys) and 19 radio-loud gamma-ray pulsars. AGILE (nominal sensitivity map) is expected to detect 13 radio-quiet and 37 radio-loud gamma-ray pulsars, while GLAST, with greater sensitivity is expected to detect 276 radio-quiet and 344 radio-loud gamma-ray pulsars. When the Parkes multi-beam pulsar survey is excluded, the ratio of radio-loud to radio-quiet gamma-ray pulsars decreases, especially for GLAST. The decrease for EGRET is 45%, implying that some fraction of EGRET unidentified sources are radio-loud gamma-ray pulsars. In the radio geometry adopted, short period pulsars are core dominated. Unlike the EGRET gamma-ray pulsars, our model predicts that when two gamma-ray peaks appear in the pulse profile, a dominant radio core peak appears in between the gamma-ray peaks. Our findings suggest that further improvements are required in describing both the radio and gamma-ray geometries.

Some Aspects of the Radio Emission of EGRET-Detected Blazars

NASA Technical Reports Server (NTRS)

Lin, Y. C.; Bertsch, D. L.; Bloom, S. D.; Esposito, J. A.; Hartman, R. C.; Hunter, S. D.; Kniffen, D. A.; Kanbach, G.; Mayer-Hasselwander, H. A.; Michelson, P. F.

1999-01-01

It has long been recognized that the high-latitude Energetic Gamma Ray Experiment Telescope (EGRET) sources can be identified with blazars of significant radio emission. Many aspects of the relation between high-energy gamma-ray emission and radio emission of EGRET-detected blazars remain uncertain. In this paper, we use the results of the recently published Third EGRET Source Catalog to examine in more detail to what extent the EGRET flux and the radio flux are correlated. In particular we examine the correlation (or the lack of it) in flux level, spectral shape, temporal variation, and detection limit. Many significant previous studies in these areas are also evaluated.

EGRET/COMPTEL Observations of an Unusual, Steep-Spectrum Gamma-Ray Source

NASA Technical Reports Server (NTRS)

Thompson, D. J.; Bertsch, D. L.; Hartman, R. C.; Collmar, W.; Johnson, W. N.

1999-01-01

During analysis of sources below the threshold of the third EGRET catalog, we have discovered a source, named GRO J1400-3956 based on the best position, with a remarkably steep spectrum. Archival analysis of COMPTEL data shows that the spectrum must have a strong turn-over in the energy range between COMPTEL and EGRET. The EGRET data show some evidence of time variability, suggesting an AGN, but the spectral change of slope is larger than that seen for most gamma-ray blazars. The sharp cutoff resembles the high-energy spectral breaks seen in some gamma-ray pulsars. There have as yet been no OSSE observations of this source.

Studying the High Energy Gamma Ray Sky with Gamma Ray Large Area Space Telescope (GLAST)

NASA Technical Reports Server (NTRS)

Kamae, T.; Ohsugi, T.; Thompson, D. J.; Watanabe, K.

1998-01-01

Building on the success of the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory, the Gamma Ray Large Area Space Telescope (GLAST) will make a major step in the study of such subjects as blazars, gamma Ray bursts, the search for dark matter, supernova remnants, pulsars, diffuse radiation, and unidentified high energy sources. The instrument will be built on new and mature detector technologies such as silicon strip detectors, low-power low-noise LSI, and a multilevel data acquisition system. GLAST is in the research and development phase, and one full tower (of 25 total) is now being built in collaborating institutes. The prototype tower will be tested thoroughly at Stanford Linear Accelerator Center (SLAC) in the fall of 1999.

Observation of Nonthermal Emission from the Supernova Remnant IC443 with RXTE

NASA Technical Reports Server (NTRS)

Sturner, S. J.; Keohane, J. W.; Reimer, O.

2002-01-01

In this paper we present analysis of X-ray spectra from the supernova remnant IC443 obtained using the PCA on RXTE. The spectra in the 3 - 20 keV band are well fit by a two-component model consisting of thermal and nonthermal components. We compare these results with recent results of other X-ray missions and discuss the need for a cut-off in the nonthermal spectrum. Recent Chandra and XMM-Newton observations suggest that much of the nonthermal emission from IC443 can be attributed to a pulsar wind nebula. We present the results of our search for periodic emission in the RXTE PCA data. We then discuss the origin o f the nonthermal component and its possible association with the unidentified EGRET source.

FERMI Large Area Telescope Detection of Pulsed γ-Rays from the Vela-Like Pulsars PSR J1048–5832 and PSR J2229+6114

DOE PAGES

Abdo, A. A.; Ackermann, M.; Ajello, M.; ...

2009-11-11

Within this paper, we report the detection of γ-ray pulsations (≥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 γ-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 γ-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-downmore » 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 γ-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) × 10 –7 cm –2 s –1 for PSR J1048–5832 and (3.77 ± 0.22 ± 0.44) × 10 –7 cm –2 s –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. In conclusion, these detections add to the growing number of young γ-ray pulsars that make up the dominant population of GeV γ-ray sources in the Galactic plane.« less

Studies of EGRET sources with a novel image restoration technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tajima, Hiroyasu; Cohen-Tanugi, Johann; Kamae, Tuneyoshi

2007-07-12

We have developed an image restoration technique based on the Richardson-Lucy algorithm optimized for GLAST-LAT image analysis. Our algorithm is original since it utilizes the PSF (point spread function) that is calculated for each event. This is critical for EGRET and GLAST-LAT image analysis since the PSF depends on the energy and angle of incident gamma-rays and varies by more than one order of magnitude. EGRET and GLAST-LAT image analysis also faces Poisson noise due to low photon statistics. Our technique incorporates wavelet filtering to minimize noise effects. We present studies of EGRET sources using this novel image restoration techniquemore » for possible identification of extended gamma-ray sources.« less

Fermi Gamma-Ray Space Telescope - Science Highlights for the First Two Years on Orbit

NASA Technical Reports Server (NTRS)

Moiseev, Alexander

2011-01-01

Fermi science objectives cover probably everything in high energy astrophysics: How do super massive black holes in Active Galactic Nuclei create powerful jets of material moving at nearly light speed? What are the jets made of? What are the mechanisms that produce Gamma-Ray Burst (GRB) explosions? What is the energy budget? How does the Sun generate high-energy gamma-rays in flares? How do the pulsars operate? How many of them are around and how different are they? What are the unidentified gamma-ray sources found by EGRET? What is the origin of the cosmic rays that pervade the Galaxy? What is the nature of dark matter? Fermi LAT successfully operates on the orbit for more than 2 years and demonstrates excellent performance, which is continuously monitored and calibrated. LAT collected> 100 billion on-orbit triggers

Possible Detection of Pi(exp 0)-Decay Gamma-Ray Emission from Cyg OB2 by EGRET

NASA Technical Reports Server (NTRS)

Chen, W.; White, R. L.; Bertsch, D.

1996-01-01

We report possible detection of pi (exp 0) decay radiation from Cyg OB2, a nearby (1.7 kpc) massive OB star association. The EGRET flux (greater than 100 MeV) maps clearly indicate a point source whose error circle includes both Cyg OB2 and Cyg X-3. We show that Cyg X-3 is unlikely to be the counterpart for the EGRET source, because of the marginal spatial consistency and the lack of the 4.8 hour modulation seen in other high energy emissions from Cyg X-3. If confirmed, this will be the first detection by EGRET of massive stars.

Possible detection of π^0^-decay γ-ray emission from CYG OB2 by EGRET.

NASA Astrophysics Data System (ADS)

Chen, W.; White, R. L.; Bertsch, D.

1996-12-01

We report possible detection of π^0^-decay radiation from Cyg OB2, a nearby (1.7kpc) massive OB star association. The EGRET flux (>100MeV) maps clearly indicate a point source whose error circle includes both Cyg OB2 and Cyg X-3. We show that Cyg X-3 is unlikely to be the counterpart for the EGRET source, because of the marginal spatial consistency and the lack of the 4.8-hour modulation seen in other high energy emissions from Cyg X-3. If confirmed, this will be the first detection by EGRET of massive stars.

EGRET observations of the BL Lacertae objects 0716+714 and 0521-365

NASA Technical Reports Server (NTRS)

Lin, Y. C.; Bertsch, D. L.; Dingus, B. L.; Esposito, J. A.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Mayer-Hasselwander, H. A.

1995-01-01

During the Compton Observatory's viewing programs Phase 1 (1991 April to 1992 November, also known as the All-Sky Survey) and Phase 2 (1992 November to 1993 September), the BL Lac object 0716+714 was in the field of view of the EGRET telescope a total of six times, three times in Phase 1 and three more times in Phase 2, while the BL Lac object 0521-365 was in the field of view of EGRET only once in Phase 1. The source 0716+714 was detected in high-energy gamma rays by EGRET at a flux level of (2.0 +/- 0.4) x 10(exp -7) photons/sq cm/s for E greater than 100 MeV with a 6 sigma significance when it was first observed by EGRET in 1992 January 10 to 23. The corresponding spectral slope of the photon number distribution is determined to be -2.04 +/- 0.33. The gamma-ray flux of 0716+714 showed considerable time variability in subsequent EGRET observations. But the spectral slope stayed about the same within the statistical uncertainties of the EGRET data. The average spectral slope of the four viewing periods during which the photon flux of 0716+714 stayed above the EGRET detection threshold is found to be -1.85 +/- 0.20 from the combined data. The source 0521+365 was detected by EGRET in 1992 May 14 to June 4 at a flux level of (1.8 +/- 0.5) x 10(exp -7) photons/sq cm/s for E greater than 100 MeV with a 4 sigma significance. The corresponding spectral slope of the photon number distribution is found to be 2.16 +/- 0.36. Details of the observations of these two BL Lac objects with the EGRET telescope are presented.

Spectral determinations for discrete sources with EGRET

NASA Technical Reports Server (NTRS)

Hughes, E. B.; Nolan, P. L.

1990-01-01

The ability of the EGRET (Energetic Gamma-Ray Experimental Telescope) to determine the spectral parameters of point sources in 14-day exposures, as planned for the initial survey phase of the GRO (Gamma Ray Observatory) mission, is explored by numerical simulation. Results are given for both galactic and extragalactic objects as a function of source strength and for representative levels of diffuse background emission.

A Search for EGRET/Radio Pulsars in the ETA Carina Region

NASA Technical Reports Server (NTRS)

2002-01-01

Our analysis of EGRET data for the radio pulsar PSR B1046-58, which lies it the Eta Carina region of the Galaxy, was highly successful, resulting in the discovery of strong evidence for gamma-ray pulsations from this source. This work was published in the Astrophysical Journal. Additional support for the association was published in a companion paper in which an analysis of the X-ray counterpart to PSR B1046-58 was done, and we showed that it was the only possible counterpart to the gamma ray source within the EGRET error box.

Prospects for Pulsar Studies with the GLAST Large Area Telescope

NASA Technical Reports Server (NTRS)

Harding, Alice K.

2006-01-01

The Large Area Telescope (LAT) on the Gamma-ray Large Area Space Telescope (GLAST) will have unprecedented sensitivity and energy resolution for gamma-rays in the range of 30 MeV to 200 GeV. GLAST is therefore expected to provide major advances in the understanding of high-energy emission from rotation-powered pulsars. As the only presently known galactic GeV source class, pulsars will be one of the most important sources for study with GLAST. The main science goals of the LAT for pulsar studies include an increase in the number of detected radio-loud and radio-quiet gamma ray pulsars, including millisecond pulsars, giving much better statistics for elucidating population characteristics, measurement of the high-energy spectrum and the shape of spectral cutoffs and determining pulse profiles for a variety of pulsars of different age. Further, measurement of phase-resolved spectra and energy dependent pulse profiles of the brighter pulsars should allow detailed tests of magnetospheric particle acceleration and radiation mechanisms, by comparing data with theoretical models that have been developed. Additionally, the LAT will have the sensitivity to allow blind pulsation searches of nearly all unidentified EGRET sources, to possibly uncover more radio-quiet Geminga-like pulsars.

The Gamma-Ray Bright BL Lac Object RX J1211+2242

NASA Technical Reports Server (NTRS)

Beckmann, V.; Favre, P.; Tavecchio, F.; Bussien, T.; Fliri, J.; Wolter, A.

2004-01-01

RX J1211+2242 is an optically faint (B approximately equal to 19.2mag) but X-ray bright (f2-10kev = 5 x l0(exp -12)erg per square centimeter per second) AGN, which has been shown to be a BL Lac object at redshift z = 0.455. The ROSAT X-ray, Calar Alto optical, and NVSS radio data suggest that the peak of the synchrotron emission of this object is at energies as high as several keV. BeppoSAX observations have been carried out simultaneously with optical observations in order to extend the coverage to higher energies. The new data indeed indicate a turn-over in the 2 - 10keV energy region. We propose that RX J1211+2242 is the counterpart of the unidentified EGRET source 3EG J1212+2304, making it a gamma-ray emitter with properties similar to, for example, Markarian 501 in its bright state, though being at a much larger distance.

The Highest-Energy Photons Seen by the Energetic Gamma-Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory

NASA Technical Reports Server (NTRS)

Thompson, D. J.; Bertsch, D. L.; ONeal, R. H., Jr.

2005-01-01

During its nine-year lifetime, the Energetic Gamma Ray Experiment Telescope (EGBET) on the Compton Gamma Ray Observatory (CGRO) detected 1506 cosmic photons with measured energy E>10 GeV. Of this number, 187 are found within a 1 deg of sources that are listed in the Third EGRET Catalog and were included in determining the detection likelihood, flux, and spectra of those sources. In particular, five detected EGRET pulsars are found to have events above 10 GeV, and together they account for 37 events. A pulsar not included in the Third EGRET Catalog has 2 events, both with the same phase and in one peak of the lower-energy gamma-ray light-curve. Most of the remaining 1319 events appear to be diffuse Galactic and extragalactic radiation based on the similarity of the their spatial and energy distributions with the diffuse model and in the E>100, MeV emission. No significant time clustering which would suggest a burst was detected.

An unidentified TeV source in the vicinity of Cygnus OB2

NASA Astrophysics Data System (ADS)

Aharonian, F.; Akhperjanian, A.; Beilicke, M.; Bernlöhr, K.; Börst, H.; Bojahr, H.; Bolz, O.; Coarasa, T.; Contreras, J.; Cortina, J.; Denninghoff, S.; Fonseca, V.; Girma, M.; Götting, N.; Heinzelmann, G.; Hermann, G.; Heusler, A.; Hofmann, W.; Horns, D.; Jung, I.; Kankanyan, R.; Kestel, M.; Kettler, J.; Kohnle, A.; Konopelko, A.; Kornmeyer, H.; Kranich, D.; Krawczynski, H.; Lampeitl, H.; Lopez, M.; Lorenz, E.; Lucarelli, F.; Magnussen, N.; Mang, O.; Meyer, H.; Milite, M.; Mirzoyan, R.; Moralejo, A.; Ona, E.; Panter, M.; Plyasheshnikov, A.; Prahl, J.; Pühlhofer, G.; Rauterberg, G.; Reyes, R.; Rhode, W.; Ripken, J.; Röhring, A.; Rowell, G. P.; Sahakian, V.; Samorski, M.; Schilling, M.; Schröder, F.; Siems, M.; Sobzynska, D.; Stamm, W.; Tluczykont, M.; Völk, H. J.; Wiedner, C. A.; Wittek, W.; Uchiyama, Y.; Takahashi, T.; HEGRA Collaboration

2002-10-01

Deep observation ( ~ 113 hrs) of the Cygnus region at TeV energies using the HEGRA stereoscopic system of air Čerenkov telescopes has serendipitously revealed a signal positionally inside the core of the OB association Cygnus OB2, at the edge of the 95% error circle of the EGRET source 3EG J2033+4118, and ~ 0.5o north of Cyg X-3. The source centre of gravity is RA alphaJ2000: 20h 32m 07s+/- 9.2sstat +/-2.2ssys, Dec deltaJ2000: +41o 30' 30''+/- 2.0'stat +/- 0.4'sys. The source is steady, has a post-trial significance of +4.6sigma , indication for extension with radius 5.6' at the ~ 3sigma level, and has a differential power-law flux with hard photon index of -1.9 +/-0.3stat +/-0.3sys. The integral flux above 1 TeV amounts ~ 3% that of the Crab. No counterpart for the TeV source at other wavelengths is presently identified, and its extension would disfavour an exclusive pulsar or AGN origin. If associated with Cygnus OB2, this dense concentration of young, massive stars provides an environment conducive to multi-TeV particle acceleration and likely subsequent interaction with a nearby gas cloud. Alternatively, one could envisage gamma -ray production via a jet-driven termination shock.

Radio to Gamma-Ray Emission from Shell-Type Supernova Remnants: Predictions from Non-Linear Shock Acceleration Models

NASA Technical Reports Server (NTRS)

Baring, Matthew G.; Ellison, Donald C.; Reynolds, Stephen P.; Grenier, Isabelle A.; Goret, Philippe

1998-01-01

Supernova remnants (SNRs) are widely believed to be the principal source of galactic cosmic rays, produced by diffusive shock acceleration in the environs of the remnant's expanding blast wave. Such energetic particles can produce gamma-rays and lower energy photons via interactions with the ambient plasma. The recently reported observation of TeV gamma-rays from SN1006 by the CANGAROO Collaboration, combined with the fact that several unidentified EGRET sources have been associated with known radio/optical/X-ray-emitting remnants, provides powerful motivation for studying gamma-ray emission from SNRs. In this paper, we present results from a Monte Carlo simulation of non-linear shock structure and acceleration coupled with photon emission in shell-like SNRs. These non-linearities are a by-product of the dynamical influence of the accelerated cosmic rays on the shocked plasma and result in distributions of cosmic rays which deviate from pure power-laws. Such deviations are crucial to acceleration efficiency considerations and impact photon intensities and spectral shapes at all energies, producing GeV/TeV intensity ratios that are quite different from test particle predictions.

Prospects for Pulsar Studies with the GLAST Large Area Telescope

NASA Technical Reports Server (NTRS)

Harding, Alice K.

2007-01-01

The Large Area Telescope (LAT) on the Gamma-ray Large Area Space Telescope (GLAST), due to launch in November 2007, will have unprecedented sensitivity and energy resolution for gamma-rays in the range of 30 MeV to 200 GeV. GLAST is therefore expected to provide major advances in the understanding of high-energy emission from rotation-powered pulsars. As the only presently known galactic GeV source class; pulsars will be one of the most important sources for study with GLAST. The main science goals of the LAT for pulsar studies include an increase in the number of detected radio-loud and radio-quiet gamma-ray pulsars, including millisecond pulsars, giving much better statistics for elucidating population characteristics, measurement of the high-energy spectrum and the shape of spectral cutoffs and determining pulse profiles for a variety of pulsars of different age. Further, measurement of phase-resolved spectra and energy dependent pulse profiles of the brighter pulsars should allow detailed tests of magnetospheric particle acceleration and radiation mechanisms, by comparing data with theoretical models that have been developed. Additionally, the LAT will have the sensitivity to allow blind pulsation searches of nearly all unidentified EGRET sources, to possibly uncover more radio-quiet Geminga-like pulsars.

Analysis of Data from the Energetic Gamma-Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory

NASA Technical Reports Server (NTRS)

Kniffen, Donald A.; Elliott, William W.

1999-01-01

The final report consists of summaries of work proposed, work accomplished, papers and presentations published and continuing work regarding the cooperative agreement. The work under the agreement is based on high energy gamma ray source data analysis collected from the Energetic Gamma-Ray Experiment Telescope (EGRET).

Fermi Large Area Telescope observations of PSR J1836+5925

DOE PAGES

Abdo, A. A.; Ackermann, M.; Ajello, M.; ...

2010-03-11

The discovery of the γ-ray pulsar PSR J1836+5925, powering the formerly unidentified EGRET source 3EG J1835+5918, was one of the early accomplishments of the Fermi Large Area Telescope (LAT). Sitting 25° off the Galactic plane, PSR J1836+5925 is a 173 ms pulsar with a characteristic age of 1.8 million years, a spindown luminosity of 1.1 × 10 34 erg s –1, and a large off-peak (OP) emission component, making it quite unusual among the known γ-ray pulsar population. We present an analysis of one year of LAT data, including an updated timing solution, detailed spectral results, and a long-term lightmore » curve showing no indication of variability. No evidence for a surrounding pulsar wind nebula is seen and the spectral characteristics of the OP emission indicate it is likely magnetospheric. Finally, analysis of recent XMM-Newton observations of the X-ray counterpart yields a detailed characterization of its spectrum, which, like Geminga, is consistent with that of a neutron star showing evidence for both magnetospheric and thermal emission.« less

A Possible X-Ray and Radio Counterpart of the High-Energy Gamma-Ray Source 3EG J2227+6122

NASA Technical Reports Server (NTRS)

Halpern, Jules P.; Gotthelf, E. V.; Helfand, D. J.; Leighly, K. M.; Oliversen, Ronald (Technical Monitor)

2001-01-01

The identity of the persistent EGRET sources in the Galactic plane is largely a mystery. For one of these, 3EG J2227+6122, our complete census of X-ray and radio sources in its error circle reveals a remarkable superposition of an incomplete radio shell with a flat radio spectrum, and a compact, power-law X-ray source with photon index Gamma = 1.5 and with no obvious optical counterpart. The radio shell is polarized at a level of approx. = 25%. The anomalous properties of the radio source prevent us from deriving a completely satisfactory theory as to its nature. Nevertheless, using data from ROSAT, ASCA, the VLA, and optical imaging and spectroscopy, we argue that the X-ray source may be a young pulsar with an associated wind-blown bubble or bow shock nebula, and an example of the class of radio-quiet pulsars which are hypothesized to comprise the majority of EGRET sources in the Galaxy. The distance to this source can be estimated from its X-ray absorption as 3 kpc. At this distance, the X-ray and gamma-ray luminosities would be approx. = 1.7 x 10(exp 33) and approx. = 3.7 x 10(exp 35) erg/s, respectively, which would require an energetic pulsar to power them. If, on the contrary, this X-ray source is not the counterpart of 3EG J2227+6122, then by process of elimination the X-ray luminosity of the latter must be less than 10(exp -4) of its gamma-ray luminosity, a condition not satisfied by any established class of gamma-ray source counterpart. This would require the existence of at least a quantitatively new type of EGRET source, as has been suggested in studies of other EGRET fields.

EGRET Diffuse Gamma Ray Maps Between 30 MeV and 10 GeV

NASA Technical Reports Server (NTRS)

Cillis, A, N.; Hartman, R. C.

2004-01-01

This paper presents all-sky maps of diffuse gamma radiation in various energy ranges between 30 MeV and 10 GeV, based on data collected by the EGRET instrument on the Compton Gamma Ray Observatory. Although the maps can be used for a variety of applications. the immediate goal is the generation of diffuse gamma-ray maps which can be used as a diffuse background/foreground for point source analysis of the data to be obtained from new high-energy gamma-ray missions like GLAST and AGILE. To generate the diffuse gamma maps from the raw EGRET maps, the point sources in the Third EGRET Catalog were subtracted out using the appropriate point spread function for each energy range. After that, smoothing was performed to minimize the effects of photon statistical noise. A smoothing length of 1 deg vas used for the Galactic plane maps. For the all-sky maps, a procedure was used which resulted in a smoothing length roughly equivalent to 4 deg. The result of this work is 16 maps of different energy intervals for absolute value of b < or equal to 20 deg, and 32 all-sky maps, 16 in equatorial coordinates (J2000) and 16 in Galactic coordinates.

EGRET Diffuse Gamma Ray Maps Between 30 MeV and 10 GeV

NASA Technical Reports Server (NTRS)

Cillis, A. N.; Hartman, R. C.

2004-01-01

This paper presents all-sky maps of diffuse gamma radiation in various energy ranges between 30 MeV and 10 GeV, based on data collected by the EGRET instrument on the Compton Gamma Ray Observatory. Although the maps can be used for a variety of applications, the immediate goal is the generation of diffuse gamma-ray maps which can be used as a diffuse background/foreground for point source analysis of the data to be obtained from new high-energy gamma-ray missions like GLAST and AGILE. To generate the diffuse gamma maps from the raw EGRET maps, the point sources in the Third EGRET Catalog were subtracted out using the appropriate point spread function for each energy range. After that, smoothing was performed to minimize the effects of photon statistical noise. A smoothing length of 1deg was used for the Galactic plane maps. For the all-sky maps, a procedure was used which resulted in a smoothing length roughly equivalent to 4deg. The result of this work is 16 maps of different energy intervals for [b]less than or equal to 20deg, and 32 all-sky maps, 16 in equatorial coordinates (J2000) and 16 in Galactic coordinates.

Experimental infection of Contracaecum multipapillatum (Nematoda: Anisakinae) from Mexico in the domestic cat.

PubMed

Vidal-Martínez, V M; Osorio-Sarabia, D; Overstreet, R M

1994-08-01

Juveniles of Contracaecum multipapillatum infected the Mayan cichlid (Cichlasoma urophthalmus) and adults infected the olivaceous cormorant (Phalacrocorax olivaceus) and the great egret (Casmerodius albus) in the coastal lagoon at Celestun, State of Yucatan, Mexico. All are new host records, and, even though the geographic locality record of Mexico for the species has not been published, unidentified but presumably conspecific specimens have been reported from there. When juveniles of C. multipapillatum were fed to a kitten, but not rats, ducks, or chickens, they developed into adults. Measurements and morphological data are provided on the specimens from the kitten. Development of an avian ascaridoid in the intestine of a mammal increases the potential of this widespread species to infect other mammals, including humans.

Egret-Hibernia(!), a significant petroleum system, northern Grand Banks area, offshore eastern Canada

USGS Publications Warehouse

Magoon, L.B.; Hudson, T.L.; Peters, K.E.

2005-01-01

Egret-Hibernia(!) is a well-explored petroleum system (3.25 billion barrels oil equivalent [BOE]) located in the Jeanne d'Arc Basin on the Labrador - Newfoundland shelf. Rifting and sediment fill began in the Late Triassic. Egret source rock was deposited in the Late Jurassic at about 153 Ma. After this time, alternating reservoir rock and seal rock were deposited with some syndepositional faulting. By the end of the Early Cretaceous, faults and folds had formed numerous structural traps. For the next 100 m.y., overburden rock thermally matured the source rock when it reached almost 4 km (2.5 mi) burial depth. For 2 km (1.25 mi) below this depth, oil and gas were expelled, until the source was depleted. The expelled petroleum migrated updip to nearby faulted, anticlinal traps, where much of it migrated across faults and upsection to the Hibernia Formation (44% recoverable oil) and Avalon Formation (28%). Accumulation size decreased, and gas content increased from west to east, independent of trap size. These changes correspond to a decrease in source rock richness and quality from west to east. Almost all (96%) of the discovered petroleum resides in the Lower Cretaceous or older reservoir rock units. All accumulations found to date are normally pressured in structural traps. Fifty-two exploration wells found eighteen discoveries. Their size ranges from 1.2 to 0.01 billion BOE. Most discoveries were made between 1979 and 1991. The discovery cycle began with larger accumulations and progressed to smaller accumulations. The estimated sizes of the larger accumulations have grown since 1990. Estimated mean value for undiscovered hydrocarbons is 3.8 billion BOE, thereby raising the ultimate size of Egret-Hibernia(!) to 6.19 billion BOE. Copyright ?? 2005. The American Association of Petroleum Geologists. All rights reserved.

Time correlations between low and high energy gamma rays from discrete sources

NASA Technical Reports Server (NTRS)

Ellsworth, R. W.

1995-01-01

Activities covered the following areas: (1) continuing analysis of the Cygnus Experiment data on the shadowing of cosmic rays by the moon and sun, which led to a direct confirmation of the angular resolution of the CYGNUS EAS array; and (2) development of analysis methods for the daily search overlapping with EGRET targets. To date, no steady emission of ultrahigh energy (UHE) gamma rays from any source has been detected by the Cygnus Experiment, but some evidence for sporadic emission had been found. Upper limits on steady fluxes from 49 sources in the northern hemisphere have been published. In addition, a daily search of 51 possible sources over the interval April 1986 to June 1992 found no evidence for emission. From these source lists, four candidates were selected for comparison with EGRET data.

The Energetic Gamma-Ray Experiment Telescope (EGRET) Science Symposium

NASA Technical Reports Server (NTRS)

Fichtel, Carl E. (Editor); Hunter, Stanley D. (Editor); Sreekumar, Parameswaran (Editor); Stecker, Floyd W. (Editor)

1990-01-01

The principle purpose of this symposium is to provide the EGRET (Energetic Gamma-Ray Experiment Telescope) scientists with an opportunity to study and improve their understanding of high energy gamma ray astronomy. The Symposium began with the galactic diffusion radiation both because of its importance in studying galactic cosmic rays, galactic structure, and dynamic balance, and because an understanding of its characteristics is important in the study of galactic sources. The galactic objects to be reviewed included pulsars, bursts, solar flares, and other galactic sources of several types. The symposium papers then proceeded outward from the Milky Way to normal galaxies, active galaxies, and the extragalactic diffuse radiation.

A Multi-Wavelength Search for a Counterpart of the Unidentified Gamma-ray source 3EG J2020+4017 (2CG078+2)

NASA Technical Reports Server (NTRS)

Becker, Werner; Weisskopf, Martin C.; Arzoumanian, Zaven; Lorimer, Duncan; Camilo, Fernando; Elsner, Ronald F.; Kanbach, Gottfried; Reimer, Olaf; Swartz, Douglas A.; Tennant, Allyn F.

2004-01-01

In search of the counterpart to the brightest unidentified gamma-ray source 3EG J2020+4017 (2CG078+2) we report on new X-ray and radio observations of the gamma-Cygni field with the Chandra X-ray Observatory and with the Green Bank Telescope (GBT). We also report on reanalysis of archival ROSAT data. With Chandra it became possible for the first time to measure the position of the putative gamma-ray counterpart RX J2020.2+4026 with sub-arcsec accuracy and to deduce its X-ray spectral characteristics. These observations demonstrate that RX J2020.2+4026 is associated with a K field star and therefore is unlikely to be the counterpart of the bright gamma-ray source 2CG078+2 in the SNR G78.2+2.1 as had been previously suggested. The Chandra observation detected 37 additional X-ray sources which were correlated with catalogs of optical and infrared data. Subsequent GBT radio observations covered the complete 99% EGRET likelihood contour of 3EG J2020+4017 with a sensitivity limit of L(sub 820) approx. 0.1 mJy kpc(exp 2) which is lower than most of the recent deep radio search limits. If there is a pulsar operating in 3EG J2020+4017, this sensitivity limit suggests that the pulsar either does not produce significant amounts of radio emission or that its geometry is such that the radio beam does not intersect with the line of sight. Finally, reanalysis of archival ROSAT data leads to a flux upper limit of f(sub x)(0.1-2.4 keV) < 1.8 x 10(exp -13) erg/s/sq cm for a putative point-like X-ray source located within the 68% confidence contour of 3EG J2020+4017. Adopting the SNR age of 5400 yrs and assuming a spin-down to X-ray energy conversion factor of 10(exp -3) this upper limit constraints the parameters of a putative neutron star as a counterpart for 3EG J2020+4017 to be P > or approx. 160/(d/1.5 kpc) ms, P > or approx. 5 x 10(exp -13)/(d/1.5kpc) s s1 and B > or approx. 9 x 10(exp 12)/(d/1.5 kpc) G.

300 GeV Observations of Unidentified EGRET Sources. A Search for TeV Counterparts to BATSE Gamma-ray Bursts

NASA Technical Reports Server (NTRS)

Weekes, Trevor C.

1998-01-01

There are few things more intriguing in high energy astrophysics than the study of the highest energy particles in the universe. Where and how these particles achieve their extreme energies is of interest not only to the astrophysicist but also to the particle physicist. At GeV and TeV energies the problem is manageable since the physics is known and the acceleration processes feasible. But the energy spectrum extends to 10(exp 20)Ev and there the problem of their origin is both more difficult and interesting; in fact at these high energies we do not even know what the particles are. The study of the origin and distribution of relativistic particles in the universe has been a challenge for more than 80 years but it is only in recent years that the technology has become available to really address the question. Although something can be learned from studies of composition and energy spectrum, the origins (and thence the acceleration mechanisms) can only come from the direct study of the neutral particle component (in this respect the highest energy particles are effectively neutral since they are virtually undeflected). The feasible channels of investigation are therefore the study of the arrival directions of: (1) TeV photons (covered by the following U.S. experiments: STACEE, Whipple/VERITAS, MILAGRO and, to some extent, by EGRET/GLAST); (2) neutrinos of TeV energy and above (AMANDA/KM3); (3) the highest energy cosmic rays (HiRes, Auger). While these studies represent a form of astronomy they are the astronomy of the extraordinary universe, the universe populated by the most dynamic and physically exciting objects, the universe of the high energy astrophysicist whose cosmic laboratories represent conditions beyond anything that can be duplicated in a terrestrial laboratory. This extraordinary astronomy may say little about the normal evolution of stars and galaxies but it opens windows into cosmic particle acceleration where new and strange physical processes take place.

EGRET observations of bursts at MeV energies

NASA Astrophysics Data System (ADS)

Catelli, J. R.; Dingus, B. L.; Schneid, E. J.

1998-05-01

We present preliminary results from the analysis of 16 bright bursts that have been observed by the EGRET NaI calorimeter, or TASC. Seven bursts have been imaged in the EGRET spark chamber above 30 MeV, but in most cases the TASC data gives the highest energy spectra available for these bursts. The TASC can obtain spectral and rate information for bursts well outside the field of view of the EGRET spark chambers, and is sensitive in the energy range from 1 to 200 MeV. The spectra for these bursts are mostly consistent with a simple power law with spectral index in the range from 1.7 to 3.7, with several of the brighter bursts showing emission past 100 MeV. No high energy cutoff has been observed. These high energy photons offer important clues to the physical processes involved at the origin of burst emission. For bursts at cosmological distances extremely high bulk Lorentz factors are implied by the presence of MeV and GeV photons which have not been attenuated by pair production with the lower energy photons from the source.

EGRET Observations of the Diffuse Gamma-Ray Emission in Orion: Analysis Through Cycle 6

NASA Technical Reports Server (NTRS)

Digel, S. W.; Aprile, E.; Hunter, S. D.; Mukherjee, R.; Xu, F.

1999-01-01

We present a study of the high-energy diffuse emission observed toward Orion by the Energetic Gamma-Ray Experiment Telescope (EGRET) on the Compton Gamma-Ray Observatory. The total exposure by EGRET in this region has increased by more than a factor of two since a previous study. A simple model for the diffuse emission adequately fits the data; no significant point sources are detected in the region studied (1 = 195 deg to 220 deg and b = -25 deg to -10 deg) in either the composite dataset or in two separate groups of EGRET viewing periods considered. The gamma-ray emissivity in Orion is found to be (1.65 +/- 0.11) x 10(exp -26)/s.sr for E > 100 MeV, and the differential emissivity is well-described as a combination of contributions from cosmic-ray electrons and protons with approximately the local density. The molecular mass calibrating ratio is N(H2)/W(sub CO) = (1.35 +/- 0.15) x 10(exp 20)/sq cm.(K.km/s).

Discovery of a Nonblazar Gamma-Ray Transient Source Near the Galactic Plane: GRO J1838-04

NASA Technical Reports Server (NTRS)

Tavani, M.; Oliversen, Ronald (Technical Monitor)

2001-01-01

We report the discovery of a remarkable gamma-ray transient source near the Galactic plane, GRO J1838-04. This source was serendipitously discovered by EGRET in 1995 June with a peak intensity of approx. (4 +/- 1) x 10(exp -6) photons/sq cm s (for photon energies larger than 100 MeV) and a 5.9 sigma significance. At that time, GRO J1838-04 was the second brightest gamma-ray source in the sky. A subsequent EGRET pointing in 1995 late September detected the source at a flux smaller than its peak value by a factor of approx. 7. We determine that no radio-loud spectrally flat blazar is within the error box of GRO J1838-04. We discuss the origin of the gamma-ray transient source and show that interpretations in terms of active galactic nuclei or isolated pulsars are highly problematic. GRO J1838-04 provides strong evidence for the existence of a new class of variable gamma-ray sources.

Gamma-Ray Emision from the Broad-Line Radio Galaxy 3C 111

NASA Technical Reports Server (NTRS)

Hartman, Robert C.; Kadler, Matthias; Tueller, Jack

2008-01-01

The broad-line radio galaxy 3C 111 has been suggested as the counterpart of the Gamma-ray source 3EGJ0416+3650. While 3C 111 meets most of the criteria for a high-probability identification, like a bright fla t-spectrum radio core and a blazarlike broadband SED, in the Third EG RET Catalog, the large positional offset of about 1.5 degrees put 3C1 11 outside the 99% probability region for 3EG J0416+3650, making this association questionable. We present a re-analysis of all available data for 3C111 from the EGRET archives, resulting in probable detection of high-energy Gamma-ray emission above 1000MeV from a position clo se to the nominal position of 3C 111, in two separate viewing periods (VPs), at a 3sigma level in each. A new source, GROJ0426+3747, appea rs to be present nearby, seen only in the >1000MeV data. For >100MeV, the data are in agreement with only one source (at the original cata log position) accounting for most of the EGRET-detected emission of 3 EGJ0416+3650. A follow-up Swift UVOT/XRT observation reveals one mode rately bright X-ray source in the error box of 3EGJ0416+3650, but bec ause of the large EGRET position uncertainty, it is not certain that the X-ray and Gamma-ray sources are associated. A Swift observation of GROJ0426+3747 detected no X.ray source nearby.

User guide to Exploration and Graphics for RivEr Trends (EGRET) and dataRetrieval: R packages for hydrologic data

USGS Publications Warehouse

Hirsch, Robert M.; De Cicco, Laura A.

2015-01-01

Evaluating long-term changes in river conditions (water quality and discharge) is an important use of hydrologic data. To carry out such evaluations, the hydrologist needs tools to facilitate several key steps in the process: acquiring the data records from a variety of sources, structuring it in ways that facilitate the analysis, processing the data with routines that extract information about changes that may be happening, and displaying findings with graphical techniques. A pair of tightly linked R packages, called dataRetrieval and EGRET (Exploration and Graphics for RivEr Trends), have been developed for carrying out each of these steps in an integrated manner. They are designed to easily accept data from three sources: U.S. Geological Survey hydrologic data, U.S. Environmental Protection Agency (EPA) STORET data, and user-supplied flat files. The dataRetrieval package not only serves as a “front end” to the EGRET package, it can also be used to easily download many types of hydrologic data and organize it in ways that facilitate many other hydrologic applications. The EGRET package has components oriented towards the description of long-term changes in streamflow statistics (high flow, average flow, and low flow) as well as changes in water quality. For the water-quality analysis, it uses Weighted Regressions on Time, Discharge and Season (WRTDS) to describe long-term trends in both concentration and flux. EGRET also creates a wide range of graphical presentations of the water-quality data and of the WRTDS results. This report serves as a user guide to these two R packages, providing detailed guidance on installation and use of the software, documentation of the analysis methods used, as well as guidance on some of the kinds of questions and approaches that the software can facilitate.

The sensitivity of EGRET to gamma ray polarization

NASA Astrophysics Data System (ADS)

Mattox, John R.

1990-05-01

A Monte Carlo simulation shows that EGRET (Energetic Gamma-Ray Experimental Telescope) does not even have sufficient sensitivity to detect 100 percent polarized gamma-rays. This is confirmed by analysis of calibration data. A Monte Carlo study shows that the sensitivity of EGRET to polarization peaks around 100 MeV. However, more than 10 5 gamma-ray events with 100 percent polarization would be required for a 3 sigma significance detection - more than available from calibration, and probably more than will result from a single score source during flight. A drift chamber gamma ray telescope under development (Hunter and Cuddapah 1989) will offer better sensitivity to polarization. The lateral position uncertainty will be improved by an order of magnitude. Also, if pair production occurs in the drift chamber gas (xenon at 2 bar) instead of tantalum foils, the effects of multiple Coulomb scattering will be reduced.

The characterization of the distant blazar GB6 J1239+0443 from flaring and low activity periods

DOE PAGES

Pacciani, L.; Donnarumma, I.; Denney, K. D.; ...

2012-08-27

In 2008, AGILE and Fermi detected gamma-ray flaring activity from the unidentified EGRET source 3EG J1236+0457, recently associated with a flat spectrum radio quasar (GB6 J1239+0443) at z = 1.762. The optical counterpart of the gamma-ray source underwent a flux enhancement of a factor of 15–30 in six years, and of ~10 in six months. Here, we interpret this flare-up in terms of a transition from an accretion-disc-dominated emission to a synchrotron-jet-dominated one. We analysed a Sloan Digital Sky Survey (SDSS) archival optical spectrum taken during a period of low radio and optical activity of the source. We estimated themore » mass of the central black hole using the width of the C iv emission line. In our work, we have also investigated SDSS archival optical photometric data and ultraviolet GALEX observations to estimate the thermal disc emission contribution of GB6 J1239+0443. This analysis of the gamma-ray data taken during the flaring episodes indicates a flat gamma-ray spectrum, with an extension of up to 15 GeV, with no statistically relevant sign of absorption from the broad-line region, suggesting that the blazar zone is located beyond the broad-line region. Our result is confirmed by the modelling of the broad-band spectral energy distribution (well constrained by the available multiwavelength data) of the flaring activity periods and by the accretion disc luminosity and black hole mass estimated by us using archival data.« less

The use of feeding habitat by a colony of herons, egrets, and ibises near Beaufort, North Carolina

USGS Publications Warehouse

Custer, Thomas W.; Southern, William E.

1977-01-01

Nine species of herons were followed to their feeding sites from a nesting colony near Beaufort, North Carolina, by airplane. Except for the Cattle Egret, which flew exclusively to fields and dumps, all other species flew mainly to saltmarsh habitat. In addition, habitats were selected in relation to tidal depth and it appears, at least for the Great Egret, that low tide habitats were preferred. Most Great Egrets, White Ibises, Louisiana Herons, and Snowy Egrets flew close to the colony and numbers decreased farther from the colony. The Great Egret, Black-crowned Night Heron, and White Ibis flew farther from the colony at high than at low tide. In addition, the species differed in distance flown from the colony. Great Egrets traveled farther from the colony when they used thermals. Rate of travel to feeding sites, however, was the same whether Great Egrets used thermals or not. Aggressive encounters were observed in the Great Egret, Louisiana Heron, Snowy Egret, and Black-crowned Night Heron. Cattle Egrets and White Ibises followed other individuals to feeding sites and it appeared as though they were using the colony as an information center. The Great Egret is the only species to effectively use eelgrass beds near Beaufort. The Great Egrets use of this habitat was restricted to about 1.5 hours on either side of low tide. We suspect that other shorter legged species did not use eelgrass regularly because of its depth.

Feeding habitat use by colonially-breeding herons, egrets, and ibises in North Carolina

USGS Publications Warehouse

Custer, Thomas W.; Osborn, Ronald G.

1978-01-01

Nine species of herons, egrets, and ibises were followed by airplane from a nesting colony near Beaufort, North Carolina to their feeding sites. Except for Cattle Egrets, which flew exclusively to fields and dumps, the birds flew mainly to saltmarsh habitat. The selection of feeding habitats by Great Egrets and Louisiana Herons was directly related to tidal depth. The Great Egret was the only species that effectively used eelgrass beds, and its use of this habitat was restricted to between 1.5 h before and after low tide. We suspect that shorter-legged herons did not use eelgrass regularly because the water was too deep. Most Great Egrets, White Ibises, Louisiana Herons, and Snowy Egrets used areas near the colony (<4 km). Great Egrets, Black-crowned Night Herons, and White Ibises flew farther from the colony at high than at low tide. Great Egrets traveled farther from the colony when they used thermals; rate of travel to feeding sites was the same, however, whether or not they used thermals. Aggressive encounters were observed at the landing sites of Great Egrets, Louisiana Herons, Snowy Egrets, and Black-crowned Night Herons. In contrast to the other species studied, Cattle Egrets and White Ibises often flew in groups to feeding sites. Indirect evidence supports the hypothesis that colonies can act as "information centres," wherein unsuccessful birds follow successful ones to better feeding locations.

Prevalence of eustrongylidosis in wading birds from colonies in California, Texas, and Rhode Island, USA

USGS Publications Warehouse

Franson, J.C.; Custer, T.W.

1994-01-01

Snowy Egret (Egretta thula) and Black-crowned Night-Heron (Nycticorax nycticorax) nestlings from colonies in Texas, Rhode Island, and California and Great Egret (Casmerodius albus) nestlings from Texas were examined for eustrongylidosis, or infection by the parasitic nematode Eustrongylides spp. In 31% (24/77) of all broods examined, at least one nestling was infected. Snowy Egret broods from Texas were more frequently (100%) infected than those from California (20%) or Rhode Island (10%), and the prevalence of eustrongylidosis in 5- and 10-day-old Snowy Egret nestlings was higher in the Texas colony than the other two. Within the Texas colony, the frequency of eustrongylidosis was greater for Snowy Egret (100%) and Great Egret (80%) broods than for Black-crowned Night-Heron broods (12.5%). Also in Texas, eustrongylidosis was more frequent in 5-day-old Snowy Egret nestlings than 5-day-old Black-crowned Night-Heron or Great Egret nestlings, and in 10-day-old Snowy Egret nestlings than in 10-day-old Black-crowned Night-Heron nestlings. Eustrongylides spp. caused perforations of the gastrointestinal tract and peritonitis, particularly in Snowy Egrets.

A Search for Ultra--High-Energy Gamma-Ray Emission from Five Supernova Remnants

NASA Astrophysics Data System (ADS)

Allen, G. E.; Berley, D.; Biller, S.; Burman, R. L.; Cavalli-Sforza, M.; Chang, C. Y.; Chen, M. L.; Chumney, P.; Coyne, D.; Dion, C. L.; Dorfan, D.; Ellsworth, R. W.; Goodman, J. A.; Haines, T. J.; Hoffman, C. M.; Kelley, L.; Klein, S.; Schmidt, D. M.; Schnee, R.; Shoup, A.; Sinnis, C.; Stark, M. J.; Williams, D. A.; Wu, J.-P.; Yang, T.; Yodh, G. B.

1995-07-01

The majority of the cosmic rays in our Galaxy with energies in the range of ~1010--1014 eV are thought to be accelerated in supernova remnants (SNRs). Measurements of SNR gamma-ray spectra in this energy region could support or contradict this concept. The Energetic Gamma-Ray Experiment Telescope (EGRET) collaboration has reported six sources of gamma rays above 108 eV whose coordinates are coincident with SNRs. Five of these sources are within the field of view of the CYGNUS extensive air shower detector. A search of the CYGNUS data set reveals no evidence of gamma-ray emission at energies ~1014 eV for these five SNRs. The flux upper limits from the CYGNUS data are compared to the lower energy fluxes measured with the EGRET detector using Drury, Aharonian, & Volk's recent model of gamma-ray production in the shocks of SNRs. The results suggest one or more of the following: (1) the gamma-ray spectra for these five SNRs soften by about 1014 eV, (2) the integral gamma-ray spectra of the SNRs are steeper than about E-1.3, or (3) most of the gamma rays detected with the EGRET instrument for each SNR are not produced in the SNR's shock but are produced at some other site (such as a pulsar).

Optimal foraging of little egrets and their prey in a foraging game in a patchy environment.

PubMed

Katz, M W; Abramsky, Z; Kotler, B P; Rosenzweig, M L; Alteshtein, O; Vasserman, G

2013-03-01

We explored the behavioral game between a predator, the little egret (Egretta garzetta), and a prey, the common goldfish (Carassius auratus), in a laboratory theater containing three fish pools. We tested the hypotheses that the egrets maximize their total capture success by responding to the fish's antipredatory behavior and that the behaviors of both players respond adaptively to the density distribution of fish among the pools. One experiment presented egrets with 15 fish per pool. The second experiment used a heterogeneous environment: pools 1, 2, and 3 had 10, 15, and 20 fish, respectively. Within each pool, fish could move between a safe, covered microhabitat and a risky, open microhabitat. Only the risky habitat had food, so fish were trading off food and safety by allocating the time spent in the two habitats. Egrets spent more total time in pools with more fish and returned to them sooner. Egrets maximized the number of fish they captured by following the matching rule of the ideal free distribution. The fish used the risky but productive habitat 65% of the time during experiments without egrets, but only 9% during experiments with 15 fish and egrets present somewhere in the theater. In addition, with egrets present, fish fine-tuned their behavior by reducing their use of the risky habitat as the egrets increased the frequency of their visits.

Pulsed high-energy gamma rays from PSR 1055-52

NASA Technical Reports Server (NTRS)

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.

Diffuse Galactic Continuum Gamma Rays. A Model Compatible with EGRET Data and Cosmic-ray Measurements

NASA Technical Reports Server (NTRS)

Strong, Andrew W.; Moskalenko, Igor V.; Reimer, Olaf

2004-01-01

We present a study of the compatibility of some current models of the diffuse Galactic continuum gamma-rays with EGRET data. A set of regions sampling the whole sky is chosen to provide a comprehensive range of tests. The range of EGRET data used is extended to 100 GeV. The models are computed with our GALPROP cosmic-ray propagation and gamma-ray production code. We confirm that the "conventional model" based on the locally observed electron and nucleon spectra is inadequate, for all sky regions. A conventional model plus hard sources in the inner Galaxy is also inadequate, since this cannot explain the GeV excess away from the Galactic plane. Models with a hard electron injection spectrum are inconsistent with the local spectrum even considering the expected fluctuations; they are also inconsistent with the EGRET data above 10 GeV. We present a new model which fits the spectrum in all sky regions adequately. Secondary antiproton data were used to fix the Galactic average proton spectrum, while the electron spectrum is adjusted using the spectrum of diffuse emission it- self. The derived electron and proton spectra are compatible with those measured locally considering fluctuations due to energy losses, propagation, or possibly de- tails of Galactic structure. This model requires a much less dramatic variation in the electron spectrum than models with a hard electron injection spectrum, and moreover it fits the y-ray spectrum better and to the highest EGRET energies. It gives a good representation of the latitude distribution of the y-ray emission from the plane to the poles, and of the longitude distribution. We show that secondary positrons and electrons make an essential contribution to Galactic diffuse y-ray emission.

Does the Blazar Gamma-ray Spectrum Harden with Increasing Flux? - Analysis of Nine Years of EGRET Data

NASA Technical Reports Server (NTRS)

Nandikotkur, Giridhar; Jahoda, Keith M.; Hartman, R. C.; Mukherjee, R.; Sreekumar, P.; Boettcher, M.

2007-01-01

The Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory (CGRO) discovered gamma-ray emission from more than 67 blazars during its nine-year lifetime. We conducted an exhaustive search of the EGRET archives and selected all the blazars that were observed multiple times and were bright enough to enable a spectral analysis using standard powerlaw models. The sample consists of 18 flat-spectrum radio quasars (FSRQs), 6 low-frequency-peaked BL Lacs (LBLs) and 2 high-frequency-peaked BL Lacs (HBLs). We do not detect any clear pattern in'the variation of spectral index with flux. Some of the blazars do not show any statistical evidence for spectral variability. The spectrum hardens with increasing flux in a few cases. There is also evidence for a flux-hardness anticorrelation at lo\\v fluxes in five blazars. The well observed blazars (3C 279,3C 273, PKS 0528-i-134, PKS 1622-297, PKS 0208- 512) do not show any overall trend in the long-term spectral dependence on flux, but the sample shows a mixture of hard and soft states. We observed spectral hysteresis at weekly timescales in all the three FSRQs for which data from flares lasting for 3 approx. 4 weeks were available. All three sources show a counterclockwise rotation despite the widely different flux profiles. Hysteresis in the spectral index vs. flux space has never been observed in FSRQs in gamma-rays at weekly timescales. itre analyze the observed spectral behavior in the context of various inverse-Compton mechanisms believed to be responsible for emission in the EGRET energy range. Our analysis uses the EGRET skymaps that were regenerated to include the changes in performance during the mission.

Heavy metal and selenium levels in feathers of young egrets and herons from Hong Kong and Szechuan, China.

PubMed

Burger, J; Gochfeld, M

1993-09-01

Several species of herons and egrets frequently nest in colonies in areas where humans also concentrate. Since the birds feed on intermediate-sized fish that themselves concentrate pollutants, they can be used not only to assess the levels of contaminants in avian tissues but as indicators of contaminants in the environment. The concentration of heavy metals and selenium in the breast feathers of fledgling black-crowned night herons Nycticorax nycticorax and Chinese pond herons Ardeola bacchus from the Tu Jing Yan heronry outside Chengdu, Szechuan Province in China; and from fledgling black-crowned night heron, little egret Egretta garzetta, great egret Egretta alba and cattle egret Bubulcus ibis from the Mai Po heronry in Hong Kong, were determined. Breast feathers were also collected from adult great egrets in Hong Kong. Adult great egrets had significantly higher levels of all heavy metals than did young great egrets. There were no significant interspecific differences in metal levels among the young at Szechuan China, except for chromium (pond herons had higher levels). There were significant differences among the young nesting at Hong Kong for all metals examined. Great egrets had lower, and night herons had higher, levels of lead than the other young. Night herons also had the highest levels of cadmium, manganese, and selenium compared to the other young. Great egret chicks had the lowest mercury levels, while little egret had the highest levels. Lead levels for all the birds in both Hong Kong and Szechuan were among the highest in the world, and this was attributed to the continued use of leaded gasoline.

Nesting season food habits of 4 species of Herons and Egrets at Lake Okeechobee, Florida

USGS Publications Warehouse

Smith, J.P.

1997-01-01

Based on the composition of nestling regurgitations collected during 3 breeding seasons, fish were the most important prey group for Great Egrets (Ardea alba: N = 200 nest-day samples; aggregate percent biomass [APB] = 73.4%), Snowy Egrets (Egretta thula: N = 115; APB = 91.4%), and Tricolored Herons (E. tricolor. N = 68; APB = 97.3%). For Little Blue Herons (E. caerulerr. N = 57), grass shrimp (Palaemoneles paludosus; APB = 39.7%) ranked higher in overall importance than all fishes combined (APB = 36.5%). Dietary overlap, as measured by Schoener's Similarity Index, was greatest between Snowy Egrets and Tricolored Herons (77%) and lowest between Tricolored Herons and Little Blue Herons (30%). Diet diversity, as measured by Shannon's Index, was highest for Great Egrets (2.04), intermediate for Snowy Egrets (1.71) and Tricolored Herons (1.68), and lowest for Little Blue Herons (1.60). Great Egrets ate a wider variety of fish species and sizes, especially larger fishes, and more crayfish than the other species. Little Blue Herons ate fewer fish and more grass shrimp and insects, and ate smaller forage fishes than Tricolored Herons but similar-sized fish as Snowy Egrets. The coarse-scale trophic composition of Snowy Egret and Tricolored Heron diets did not differ significantly, but Tricolored Herons ate larger forage fishes than Snowy Egrets. Pronounced interannual and intercolony variation in diet composition suggested that Great Egrets and Little Blue Herons switched prey types as hydrologic conditions and habitat availability changed. Conversely, lack of such variation suggested that Snowy Egrets and Tricolored Herons adjusted their foraging tactics to ensure contin-ued encounters with preferred prey despite changing habitat conditions. These results are generally consistent with other published data, help confirm some generalizations about foraging strategies and patterns of niche differentiation among these ecologically similar species, and have implications for managing the Lake Okeechobce ecosystem.

Nesting season food habits of 4 species of herons and egrets at Lake Okeechobee, Florida

USGS Publications Warehouse

Smith, Jeff P.

1997-01-01

Based on the composition of nestling regurgitations collected during 3 breeding seasons, fish were the most important prey group for Great Egrets (Ardea alba: N = 200 nest-day samples; aggregate percent biomass [APB] = 73.4%), Snowy Egrets (Egretta thula: N = 115; APB = 91.4%), and Tricolored Herons (E. tricolor: N = 68; APB = 97.3%). For Little Blue Herons (E. caerulea: N = 57), grass shrimp (Palaemonetes paludosus; APB = 39.7%) ranked higher in overall importance than all fishes combined (APB = 36.5%). Dietary overlap, as measured by Schoener's Similarity Index, was greatest between Snowy Egrets and Tricolored Herons (77%) and lowest between Tricolored Herons and Little Blue Herons (30%). Diet diversity, as measured by Shannon's Index, was highest for Great Egrets (2.04), intermediate for Snowy Egrets (1.71) and Tricolored Herons (1.68), and lowest for Little Blue Herons (1.60). Great Egrets ate a wider variety of fish species and sizes, especially larger fishes, and more crayfish than the other species. Little Blue Herons ate fewer fish and more grass shrimp and insects, and ate smaller forage fishes than Tricolored Herons but similar-sized fish as Snowy Egrets. The coarse-scale trophic composition of Snowy Egret and Tricolored Heron diets did not differ significantly, but Tricolored Herons ate larger forage fishes than Snowy Egrets. Pronounced interannual and intercolony variation in diet composition suggested that Great Egrets and Little Blue Herons switched prey types as hydrologic conditions and habitat availability changed. Conversely, lack of such variation suggested that Snowy Egrets and Tricolored Herons adjusted their foraging tactics to ensure continued encounters with preferred prey despite changing habitat conditions. These results are generally consistent with other published data, help confirm some generalizations about foraging strategies and patterns of niche differentiation among these ecologically similar species, and have implications for managing the Lake Okeechobee ecosystem.

EGRET sources at intermediate galactic latitude

NASA Technical Reports Server (NTRS)

Halpern, Jules P. (Principal Investigator)

1996-01-01

This paper presents the abstracts of four papers (using ROSAT data) that are submitted to refereed journals during the current reporting period. The papers are: (1) Extreme x-ray variability in the narrow-line QSO PHL 1092; (2) The Geminga pulsar (soft x-ray variability and an EUVE observation); (3) a broad-band x-ray study of the geminga pulsar; and (4) Classification of IRAS-selected x-ray galaxies in the ROSAT all-sky survey. The abstracts of these papers are given in the next four sections of this report, and their status is given in the Appendix. Finally, two new projects (De-identifying a non-AGN and EGRET sources at intermediate galactic latitude) for which ROSAT data were recently received are currently being studied under this grant. A summary of work in progress on these new projects is given in the last two sections of this report.

Components of the Extragalactic Gamma-Ray Background

NASA Technical Reports Server (NTRS)

Stecker, Floyd W.; Venters, Tonia M.

2011-01-01

We present new theoretical estimates of the relative contributions of unresolved blazars and star-forming galaxies to the extragalactic gamma-ray background (EGB) and discuss constraints on the contributions from alternative mechanisms such as dark matter annihilation and truly diffuse gamma-ray production. We find that the Fermi source count data do not rule out a scenario in which the EGB is dominated by emission from unresolved blazars, though unresolved star-forming galaxies may also contribute significantly to the background, within order-of-magnitude uncertainties. In addition, we find that the spectrum of the unresolved star-forming galaxy contribution cannot explain the EGB spectrum found by EGRET at energies between 50 and 200 MeV, whereas the spectrum of unresolved flat spectrum radio quasars, when accounting for the energy-dependent effects of source confusion, could be consistent with the combined spectrum of the low-energy EGRET EGB measurements and the Fermi-Large Area Telescope EGB measurements.

The gamma-ray observatory

NASA Technical Reports Server (NTRS)

1991-01-01

An overview is given of the Gamma Ray Observatory (GRO) mission. Detection of gamma rays and gamma ray sources, operations using the Space Shuttle, and instruments aboard the GRO, including the Burst and Transient Source Experiment (BATSE), the Oriented Scintillation Spectrometer Experiment (OSSE), the Imaging Compton Telescope (COMPTEL), and the Energetic Gamma Ray Experiment Telescope (EGRET) are among the topics surveyed.

Temporal trends (1989–2011) in levels of mercury and other heavy metals in feathers of fledgling great egrets nesting in Barnegat Bay, NJ

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burger, Joanna, E-mail: burger@biology.rutgers.edu

There is an abundance of data for levels of metals from a range of species, but relatively few long-term time series from the same location. In this paper I examine the levels of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in feathers from fledgling great egrets (Ardea alba) collected at nesting colonies in Barnegat Bay, New Jersey from 1989 to 2011. The primary objectives were to test the null hypotheses that (1) There were no temporal differences in metal levels in feathers of fledgling great egrets, and (2) Great egrets nesting in different areas of Barnegat Bay (New Jersey)more » did not differ in metal levels. There were significant yearly variations in levels of all heavy metals in feathers of fledgling great egret, but levels decreased significantly from 1989 to 2011 only for lead (1470 ppb to 54.3 ppb), cadmium (277 ppb to 30.5 ppb), and manganese (only since 1996; 2669 ppb to 329 ppb)). Although mercury levels decreased from 2003–2008 (6430 ppb to 1042 ppb), there was no pattern before 2003, and levels increased after 2008 to 2610 ppb in 2011. Lead, cadmium, chromium, manganese and mercury were higher in feathers from great egrets nesting in the northern part of the bay, and selenium was highest in feathers from mid-bay. The lack of a temporal decline in mercury levels in feathers of great egrets is cause for concern, since the high levels in feathers from some years (means as high as 6430 ppb) are in the range associated with adverse effects (5000 ppb for feathers). -- Highlights: ► Metals were monitored in feathers of great egrets from Barnegat Bay, New Jersey. ► Levels of cadmium and lead decreased significantly from 1989–2011. ► Mercury levels in feathers from great egrets did not decline from 1989–2011. ► Metal levels were generally higher in great egrets and black-crowned night heron feathers than in snowy egrets.« less

EGRET upper limits to the high-energy gamma-ray emission from the millisecond pulsars in nearby globular clusters

NASA Technical Reports Server (NTRS)

Michelson, P. F.; Bertsch, D. L.; Brazier, K.; Chiang, J.; Dingus, B. L.; Fichtel, C. E.; Fierro, J.; Hartman, R. C.; Hunter, S. D.; Kanbach, G.

1994-01-01

We report upper limits to the high-energy gamma-ray emission from the millisecond pulsars (MSPs) in a number of globular clusters. The observations were done as part of an all-sky survey by the energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory (CGRO) during Phase I of the CGRO mission (1991 June to 1992 November). Several theoretical models suggest that MSPs may be sources of high-energy gamma radiation emitted either as primary radiation from the pulsar magnetosphere or as secondary radiation generated by conversion into photons of a substantial part of the relativistic e(+/-) pair wind expected to flow from the pulsar. To date, no high-energy emission has been detected from an individual MSP. However, a large number of MSPs are expected in globular cluster cores where the formation rate of accreting binary systems is high. Model predictions of the total number of pulsars range in the hundreds for some clusters. These expectations have been reinforced by recent discoveries of a substantial number of radio MSPs in several clusters; for example, 11 have been found in 47 Tucanae (Manchester et al.). The EGRET observations have been used to obtain upper limits for the efficiency eta of conversion of MSP spin-down power into hard gamma rays. The upper limits are also compared with the gamma-ray fluxes predicted from theoretical models of pulsar wind emission (Tavani). The EGRET limits put significant constraints on either the emission models or the number of pulsars in the globular clusters.

Organochlorines accumulate in heron and egret chicks sampled in the Houston Ship Channel

USGS Publications Warehouse

Custer, T.W.; Shipley, Frank S.; Kiesling, Russell W.

1991-01-01

The National Contaminant Monitoring Program (NCBP) is an effort of the U.S. Fish and Wildlife Service to measure concentrations of DDT and other persistent chemicals in the environment and to quantify changes in these levels. The NCBP has established a network of sampling stations in segments of the environment for which Federal agencies have authority. The wildlife component of this program, administered by the Patuxent Wildlife Research Center, includes the periodic sampling of European starlings (Sturnus vulgaris), mallards (Anas platyrhynchos), and American black ducks (Anas rubripes). In order to include an estuarine component into the NCBP, herons and egrets are being evaluated. Eggs and chicks (five, ten, and 15 days of age) of snowy egrets (Egretta thula), and black-crowned night-herons (Nycticorax nycticorax) were collected in Naragansett Bay, RI; the Houston Ship Channel (HSC), TX; and San Francisco Bay, CA. Great egret (Casmerodius albus) eggs and chicks also were collected at the Texas colony. Eggs and chicks were analyzed for organochlorines; trace element and petroleum hydrocarbon analyses are pending. DDE and polychlorinated biphenyls (PCBs) were detected in all eggs and chicks, and they accumulated as the chicks grew. At each location, black-crowned nightheron chicks accumulated both DDE and PCBs more rapidly than snowy egrets or great egrets. PCBs accumulated more rapidly in night-heron chicks in Rhode Island than California; however, PCB accumulation for snowy egret chicks did not differ among locations. Contaminant accumulation rates in heron and egret chicks could be used as a new wetland component of the NCBP.

Feeding habitat characteristics of the great blue heron and great egret nesting along the Upper Mississippi River, 1995-1998

USGS Publications Warehouse

Custer, Christine M.; Suarez, S.A.; Olsen, D.A.

2004-01-01

The Great Blue Heron (Ardea herodias) and Great Egret (Ardea alba) nested in eight colonies along the Upper Mississippi River, USA, and individual birds were followed by airplane to feeding sites during the nesting seasons in 1995-1998. Both species used braided channel/backwater habitats for feeding more than expected, based on availability, and open pool and main navigation channel less than expected. Most individuals of both species fed 10 km away. Habitat and distance need to be considered simultaneously when assessing habitat quality for herons and egrets. The Great Blue Heron flew farther to feeding sites during the care-of-young period than during incubation and the Great Egret showed the opposite pattern. The Great Blue Heron tended to feed solitarily; only 10% of the feeding flights ended at a location where another heron was already present. About one-third of Great Egret feeding flights ended at a location with another egret already present. Colony placement on the landscape seemed to be a function of the feeding radius of each colony.

Isolation of Salmonella spp. in cattle egrets (Bubulcus ibis) from Fernando de Noronha Archipelago, Brazil.

PubMed

Silva, Marcio A; Fernandes, Érika F S T; Santana, Sandra C; Marvulo, Maria Fernanda V; Barros, Mércia R; Vilela, Sineide M O; Reis, Eliane M F; Mota, Rinaldo A; Silva, Jean C R

2018-03-03

The growth of the population of cattle egrets (Bubulcus ibis) in the archipelago of Fernando de Noronha constitutes a threat to public health and biological diversity because of their competition with and predation on native species and the possibility of transmission of pathogens to human beings, livestock and native wildlife. The aim here was to search for, isolate and identify serovars of Salmonella in clinically healthy local cattle egrets. Cloacal swabs were obtained from 456 clinically healthy cattle egrets of both sexes and a variety of ages. The swabs were divided into 51 pools. Six of these (11.7%) presented four serovars of Salmonella enterica subspecies enterica: Salmonella serovar Typhimurium; Salmonella serovar Newport; Salmonella serovar Duisburg; and Salmonella serovar Zega. One sample was identified as S. enterica subspecies enterica O16:y:-. Results in this study suggest that cattle egrets may be reservoirs of this agent on Fernando de Noronha and represent a risk to public health and biological diversity. Copyright © 2018. Published by Elsevier Editora Ltda.

Finding X-ray counterparts for unidentified sources in the 105 months BAT survey - 1

NASA Astrophysics Data System (ADS)

Stephen, J. B.; Bassani, L.; Malizia, A.; Masetti, N.; Ubertini, P.

2018-02-01

We provide X-ray counterparts for the unidentified Swift/BAT sources listed in the 105 month catalogue (Oh et al. 2018, ApJS in press). These associations were found by cross-correlating the list of U1,U2 and U3 sources with the ROSAT Bright (RASSBSC, Voges et al. 1999, A & A, 349, 389) and the XMM-Newton Slew (XMMSlew, Saxton et al. 2008, A & A, 480, 611) catalogues.

VizieR Online Data Catalog: Unidentified gamma-ray sources. IV. X-ray (Paggi+, 2013)

NASA Astrophysics Data System (ADS)

Paggi, A.; Massaro, F.; D'Abrusco, R.; Smith, H. A.; Masetti, N.; Giroletti, M.; Tosti, G.; Funk, S.

2013-11-01

The initial sample considered in our analysis is constituted by the 299 unidentified gamma-ray sources (UGSs) in the 2FGL catalog that do not present any γ-ray analysis flag (Nolan et al. 2012, Cat. J/ApJS/199/31). After Fermi was launched, the Swift XRT Survey of Fermi Unassociated Sources was started in order to perform follow-up observations of the unidentified gamma-ray sources (UGSs) in an attempt to find their potential X-ray counterparts (PI: A. Falcone). We analyze all data collected between the beginning of the follow-up program until 2013 March 31. We note that 203 of the 205 UGSs that constitute our sample have been also observed in the optical and UV by UVOT. We then produced for each X-ray observation the corresponding merged UVOT event files, adopting standard procedures. (6 data files).

A Search for the X-ray Counterpart of the Unidentified Gamma-ray Source 3EG J2020+4017 (2CG078+2)

NASA Technical Reports Server (NTRS)

Weisskopf, Martin; Swartz, Douglas A.; Carraminana, Alberto; Carrasco, Luis; Kaplan, David L.; Becker, Werner; Elsner, Ronald F.; Kanbach, Gottfried; ODell, Stephen L.; Tennant, Allyn F.

2006-01-01

We report observations with the Chandra X-ray Observatory of a field in the gamma-Cygni supernova remnant (SNR78.2+2.1) centered on the cataloged location of the unidentified, bright gamma-ray source 3EG J2020+4017. In this search for an X-ray counterpart to the gamma-ray source, we detected 30 X-ray sources. Of these, we found 17 strong-candidate counterparts in optical (visible through near-infrared) cataloged and an additional 3 through our optical observations. Based upon colors and (for several objects) optical spectra, nearly all the optically identified objects appear to be reddened main-sequence stars: None of the X-ray sources with an optical counterpart is a plausible X-ray counterpart to 3EG J2020+4017-if that gamma-ray source is a spin-powered pulsar. Many of the 10 X-ray sources lacking optical counterparts are likely (extragalactic) active galactic nuclei, based upon the sky density of such sources. Although one of the 10 optically unidentified X-ray sources could be the gamma-ray source, there is no auxiliary evidence supporting such an identification

Finding X-ray counterparts for unidentified sources in the 105 months BAT survey - 2

NASA Astrophysics Data System (ADS)

Stephen, J. B.; Bassani, L.; Malizia, A.; Masetti, N.; Ubertini, P.

2018-02-01

We provide X-ray counterparts for unidentified Swift/BAT sources in the 105 month catalogue (Oh et al. 2018, ApJS in press). They were found by cross-correlating the list of U1,U2 and U3 sources with the ROSAT Bright (RASSBSC, Voges et al. 1999, A & A, 349, 389) and XMM-Newton Slew (XMMSlew, Saxton et al. 2008, A & A, 480, 611) catalogues and optically identified as reported in Atel #11340.

AGATE: A High Energy Gamma-Ray Telescope Using Drift Chambers

NASA Astrophysics Data System (ADS)

Mukherjee, R.; Dingus, B. L.; Esposito, J. A.; Bertsch, D. L.; Cuddapah, R.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Thompson, D. J.

1996-01-01

The exciting results from the highly successful Energetic Gamma-Ray Experiment Telescope (EGRET) instrument on the Compton Gamma-Ray Observatory (CGRO) has contributed significantly to increasing our understanding of high energy gamma-ray astronomy. A follow-on mission to EGRET is needed to continue these scientific advances as well as to address the several new scientific questions raised by EGRET. Here we describe the work being done on the development of the Advanced Gamma-Ray Astronomy Telescope Experiment (AGATE), visualized as the successor to EGRET. In order to achieve the scientific goals, AGATE will have higher sensitivity than EGRET in the energy range 30 MeV to 30 GeV, larger effective area, better angular resolution, and an extended low and high energy range. In its design, AGATE will follow the tradition of the earlier gamma-ray telescopes, SAS-2, COS B, and EGRET, and will have the same four basic components of an anticoincidence system, directional coincidence system, track imaging, and energy measurement systems. However, due to its much larger size, AGATE will use drift chambers as its track imaging system rather than the spark chambers used by EGRET. Drift chambers are an obvious choice as they have less deadtime per event, better spatial resolution, and are relatively easy and inexpensive to build. Drift chambers have low power requirements, so that many layers of drift chambers can be included. To test the feasibility of using drift chambers, we have constructed a prototype instrument consisting of a stack of sixteen 1/2m × 1/2m drift chambers and have measured the spatial resolution using atmospheric muons. The results on the drift chamber performance in the laboratory are presented here.

Salmonellosis in a captive heron colony

USGS Publications Warehouse

Locke, L.N.; Ohlendorf, H.M.; Shillinger, R.B.; Jareed, T.

1974-01-01

Salmonellosis caused by Salmonella typhimurium was one of several factors responsible for losses among young herons being held at the Patuxent Wildlife Research Center. The infection was demonstrated in five black-crowned night herons (Nycticorax nycticorax), three common egrets (Casmerodius albus), two little blue herons (Florida caerulea), one cattle egret (Bubulcus ibis), one snowy egret (Leucophoyx thula) and one Louisiana heron (Hydranassa tricolor). The disease was characterized by emaciation, focal liver necrosis, and frequently by a caseo-necrotic enteritis.

EGRET excess of diffuse galactic gamma rays as tracer of dark matter

NASA Astrophysics Data System (ADS)

de Boer, W.; Sander, C.; Zhukov, V.; Gladyshev, A. V.; Kazakov, D. I.

2005-12-01

The public data from the EGRET space telescope on diffuse Galactic gamma rays in the energy range from 0.1 to 10 GeV are reanalyzed with the purpose of searching for signals of Dark Matter annihilation (DMA). The analysis confirms the previously observed excess for energies above 1 GeV in comparison with the expectations from conventional Galactic models. In addition, the excess was found to show all the key features of a signal from Dark Matter Annihilation (DMA): a) the excess is observable in all sky directions and has the same shape everywhere, thus pointing to a common source; b) the shape corresponds to the expected spectrum of the annihilation of non-relativistic massive particles into - among others - neutral π0 mesons, which decay into photons. From the energy spectrum of the excess we deduce a WIMP mass between 50 and 100 GeV, while from the intensity of the excess in all sky directions the shape of the halo could be reconstructed. The DM halo is consistent with an almost spherical isothermal profile with substructure in the Galactic plane in the form of toroidal rings at 4 and 14 kpc from the center. These rings lead to a peculiar shape of the rotation curve, in agreement with the data, which proves that the EGRET excess traces the Dark Matter.

Feasibility for EGRET detection of antimatter concentrations in the universe

NASA Technical Reports Server (NTRS)

Hartman, R. C.

1990-01-01

Although the Grand Unified Theories of elementary particle dynamics have to some extent reduced the aesthetic attraction of matter-antimatter symmetry in the Universe, the idea is still not ruled out. Although first introduced by Alfven (1965), most of the theoretical development related to gamma-ray astronomy was carried out by Stecker, who has proposed (Stecker, Morgan, and Bredekamp, 1971) matter-antimatter annihilation extending back to large redshifts as a possible explanation of the apparently extragalactic diffuse gamma radiation. Other candidate explanations were also proposed, such as superposition of extragalactic discrete sources. Clearly, the existence of significant amounts of antimatter in the universe would be of great cosmological importance; its detection, however, is not simple. Since the photon is its own antiparticle, it carries no signature identifying whether it originated in a matter or an antimatter process; even aggregates of photons (spectra) are expected to be identical from matter and antimatter processes. The only likely indicator of the presence of concentrations of antimatter is evidence of its annihilation with normal matter, assuming there is some region of contact or overlap. The EGRET (Energetic Gamma-Ray Experimental Telescope) on the Gamma Ray Observatory, with a substantial increase in sensitivity compared with earlier high energy gamma ray telescopes, may be able to address this issue. The feasibility of using EGRET in such a search for antimatter annihilation in the Universe is considered.

A snowy egret in the waters around KSC

NASA Technical Reports Server (NTRS)

1999-01-01

A snowy egret wades the shallow waters of the Merritt Island National Wildlife Refuge, which shares a boundary with Kennedy Space Center. Ranging from northern California, Oklahoma and Maine to southern South America, the snowy egret winters north to California and South Carolina. In the East, they are best known as salt marsh birds. Once an endangered species, their numbers have increased again. The 92,000-acre refuge is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

Identifying Unidentified Fermi-LAT Objects (UFOs) at High-Latitude

NASA Astrophysics Data System (ADS)

Cheung, Chi Teddy

2009-09-01

We propose a Chandra study of 8 high Galactic latitude gamma-ray sources in the Fermi-LAT bright source list. These sources are currently unidentified, i.e., they are not clearly associated with established classes of gamma-ray emitters like blazars and pulsars. The proposed observations will determine the basic properties (fluxes, positions, hardness ratio/spectra) of all X-ray sources down to a 0.3-10 keV flux limit of 1.5e-14 erg/cm2/s within the Fermi-LAT localization circles. This will enable further follow-up at other wavelengths, with the ultimate goal to reveal the nature of these enigmatic gamma-ray sources.

On the nature of the unidentified high latitude UHURU sources

NASA Technical Reports Server (NTRS)

Holt, S. S.; Boldt, E. A.; Serlemitsos, P. J.; Murray, S. S.; Giacconi, R.; Kellogg, E. M.; Matilsky, T. A.

1973-01-01

It is found that the unidentified high latitude UHURU sources can have either of two very different explanations. They must either reside at great distances with luminosity equivalent to or greater than 10 to the 46th power ergs/sec, or be contained in the galaxy with luminosity equivalent to or less than 10 to the 34th power ergs/sec. The two possibilities are indistinguishable with the available data.

Mercury and drought along the lower Carson River, Nevada: II. Snowy egret and black-crowned night-heron reproduction on Lahontan Reservoir, 1997-2006

USGS Publications Warehouse

Hill, Elwood F.; Henry, Charles J.; Grove, Robert A.

2008-01-01

Mercury concentrations in the floodplain of the Carson River Basin in northwestern Nevada are some of the highest ever reported in a natural system. Thus, a portion of the basin including Lahontan Reservoir was placed on the U.S. Environmental Protection Agency’s Natural Priorities List for research and cleanup. Preliminary studies indicated that reproduction in piscivorous birds may be at risk. Therefore, a 10-year study (1997–2006) was conducted to evaluate reproduction of snowy egrets (Egretta thula) and black-crowned night-herons (Nycticorax nycticorax) nesting on Gull Island in Lahontan Reservoir. Special attention was given to the annual flow of the Carson River, the resultant fluctuation of this irrigation reservoir, and the annual exposure of snowy egrets and night-herons to methylmercury (MeHg). The dynamic character of the river due to flooding and drought (drought effect) influenced snowy egret and night-heron reproduction more so than did MeHg contamination of eggs. During an extended drought (2000–2004) in the middle of the study, snowy egret nests containing eggs with concentrations of MeHg (measured as total mercury [THg] ∼ 100% MeHg) ≥0.80 μg THg/g, ww, all failed, but in 1997 and 2006 (wet years with general flooding), substantial numbers of young were produced (but fewer than at nests where eggs contained <0.80 μg/g). Thus, a variable reproductive threshold of tolerance to MeHg may be associated with habitat quality (food type and abundance). Clearly, drought was the most important factor affecting snowy egret annual productivity. In contrast to snowy egrets, night-herons generally had fewer nests meeting the 0.80 μg THg/g criterion, and those above the criterion were less sensitive to mercury than were snowy egrets. Furthermore, night-herons appeared more tolerant of drought conditions than snowy egrets because they nested earlier, selected more protected nesting sites, and had a more generalist diet that provided additional food options including terrestrial organisms, which also reduced exposure to MeHg. A putative biological effect threshold of 2.0 μg THg/g in whole blood for young of both species was evaluated, which was frequently exceeded, but with no evidence, while still in the colony, of an association with direct mortality. An evaluation of physiological associations with blood residues and post-fledging survival will be presented in future reports in this series.

QUASI-STAR JETS AS UNIDENTIFIED GAMMA-RAY SOURCES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Czerny, Bozena; Sikora, Marek; Janiuk, Agnieszka

2012-08-10

Gamma-ray catalogs contain a considerable amount of unidentified sources. Many of these are located out of the Galactic plane and therefore may have extragalactic origin. Here we assume that the formation of massive black holes in galactic nuclei proceeds through a quasi-star stage and consider the possibility of jet production by such objects. Those jets would be the sources of collimated synchrotron and Compton emission, extending from radio to gamma rays. The expected lifetimes of quasi-stars are of the order of million of years while the jet luminosities, somewhat smaller than that of quasar jets, are sufficient to account formore » the unidentified gamma-ray sources. The jet emission dominates over the thermal emission of a quasi-star in all energy bands, except when the jet is not directed toward an observer. The predicted synchrotron emission peaks in the IR band, with the flux close to the limits of the available IR all sky surveys. The ratio of the gamma-ray flux to the IR flux is found to be very large ({approx}60), much larger than in BL Lac objects but reached by some radio-loud quasars. On the other hand, radio-loud quasars show broad emission lines while no such lines are expected from quasi-stars. Therefore, the differentiation between various scenarios accounting for the unidentified gamma-ray sources will be possible at the basis of the photometry and spectroscopy of the IR/optical counterparts.« less

Naturally occurring secondary nutritional hyperparathyroidism in cattle egrets (Bubulcus ibis) from central Texas.

PubMed

Phalen, David N; Drew, Mark L; Contreras, Cindy; Roset, Kimberly; Mora, Miguel

2005-04-01

Naturally occurring secondary nutritional hyperparathyroidism is described in the nestlings of two colonies of cattle egrets (Bubulcus ibis) from Central Texas (Bryan and San Antonio, Texas, USA). Nestlings from a third colony (Waco, Texas, USA) were collected in a subsequent year for comparison. Birds from the first two colonies consistently had severe osteopenia and associated curving deformities and folding fractures of their long bones. These birds also had reduced bone ash, increased osteoclasia, a marked decrease in osteoblast activity, variable lengthening and shortening of the hypertrophic zone of the epiphyseal cartilage, decreased and disorganized formation of new bone, and a marked hypertrophy and hyperplasia of the parathyroid glands as compared to birds collected from the third colony. Fibrous osteodystrophy was found in all of the birds from San Antonio and Bryan. Evidence of moderate to severe calcium deficiency was also identified in 33% of the cattle egrets collected from Waco. Gut contents of affected chicks contained predominately grasshoppers and crickets; vertebrate prey items were absent from the Bryan birds. Grasshoppers and crickets collected from fields frequented by the adult egrets in 1994 had 0.12-0.28% calcium and 0.76-0.81% phosphorus. Pooled grasshoppers and crickets collected during a subsequent wet early spring averaged 0.24% calcium and 0.65% phosphorus. Although the phosphorus content of the insect prey was adequate for growth, calcium was approximately one-third the minimum calcium requirement needed for growth for other species of birds. It was postulated that cattle egrets breeding in Central Texas have expanded their range into habitat that contains less vertebrate prey, and as a result, many nestling egrets are being fed diets that contain suboptimal calcium. Therefore, in years where vertebrate prey is scarce and forage for insect prey is reduced in calcium, nestling egrets are at risk for developing secondary nutritional hyperparathyroidism.

Naturally occurring secondary nutritional hyperparathyroidism in cattle egrets (Bubulcus ibis) from Central Texas

USGS Publications Warehouse

Phalen, D.N.; Drew, M.L.; Contreras, C.; Roset, K.; Mora, M.

2005-01-01

Naturally occurring secondary nutritional hyperparathyroidism is described in the nestlings of two colonies of cattle egrets (Bubulcus ibis) from Central Texas (Bryan and San Antonio, Texas, USA). Nestlings from a third colony (Waco, Texas, USA) were collected in a subsequent year for comparison. Birds from the first two colonies consistently had severe osteopenia and associated curving deformities and folding fractures of their long bones. These birds also had reduced bone ash, increased osteoclasia, a marked decrease in osteoblast activity, variable lengthening and shortening of the hypertrophic zone of the epiphyseal cartilage, decreased and disorganized formation of new bone, and a marked hypertrophy and hyperplasia of the parathyroid glands as compared to birds collected from the third colony. Fibrous osteodystrophy was found in all of the birds from San Antonio and Bryan. Evidence of moderate to severe calcium deficiency was also identified in 33% of the cattle egrets collected from Waco. Gut contents of affected chicks contained predominately grasshoppers and crickets; vertebrate prey items were absent from the Bryan birds. Grasshoppers and crickets collected from fields frequented by the adult egrets in 1994 had 0.12-0.28% calcium and 0.76-0.81% phosphorus. Pooled grasshoppers and crickets collected during a subsequent wet early spring averaged 0.24% calcium and 0.65% phosphorus. Although the phosphorus content of the insect prey was adequate for growth, calcium was approximately one-third the minimum calcium requirement needed for growth for other species of birds. It was postulated that cattle egrets breeding in Central Texas have expanded their range into habitat that contains less vertebrate prey, and as a result, many nestling egrets are being fed diets that contain suboptimal calcium. Therefore, in years where vertebrate prey is scarce and forage for insect prey is reduced in calcium, nestling egrets are at risk for developing secondary nutritional hyperparathyroidism. ?? Wildlife Disease Association 2005.

Feeding habitats of nesting wading birds: Spatial use and social influences

USGS Publications Warehouse

Erwin, R. Michael

1983-01-01

In an effort to relate social interactions to feeding-habitat use, I observed six species of wading birds near a major colony site in coastal North Carolina. Three spatial scales of habitat use were considered: the general orientation to and from the colony (coarsest level), the habitat "patch," and (at the finest level) the microhabitat. Departure-arrival directions of Great Egrets (Casmerodius albus), Snowy Egrets (Egretta thula), Cattle Egrets (Bubulcus ibis), Little Blue Herons (Egretta caerulea), Tricolored Herons (Egretta tricolor), and Glossy Ibises (Plegadis falcinellus) were monitored at the colony site to document coarse patterns of feeding-habitat use. Added to these data were observations made at five different wetland sites to monitor between-habitat and within-habitat patterns for the five aquatic-feeding species. The results indicated a broad and variable use of feeding habitat over time. At the coarsest scale (i.e. orientation at the colony), diffuse patterns, influenced little by either inter- or intraspecific social interaction, were found for all species. At the next level (habitat "patch"), only one of five wetland sites was relatively consistent in attracting feeding birds, and its use increased from May to June. Few groups were seen at four of the five sites. At the one "attractive" site, the within-habitat patterns again were spatially variable over time, except for those of the abundant Snowy Egret, whose microhabitat preference was fairly consistent. Glossy Ibises and Snowy Egrets frequently formed mixed-species groups, Little Blue Herons were the least social, and Great Egrets and Tricolored Herons generally occurred in groups of less than 10 birds but rarely in groups larger than 30. The close association between Snowy Egrets and Glossy Ibises appeared to be based on a "beater-follower" relationship, wherein the probing, nonvisually feeding ibises make prey more available to the followers. In the study area, local enhancement appeared to play a more important role than did any "information-sharing" at the colony.

Estimation of Polychlorinated Biphenyl Sources in Industrial Port Sediments Using a Bayesian Semifactor Model Considering Unidentified Sources.

PubMed

Anezaki, Katsunori; Nakano, Takeshi; Kashiwagi, Nobuhisa

2016-01-19

Using the chemical balance method, and considering the presence of unidentified sources, we estimated the origins of PCB contamination in surface sediments of Muroran Port, Japan. It was assumed that these PCBs originated from four types of Kanechlor products (KC300, KC400, KC500, and KC600), combustion and two kinds of pigments (azo and phthalocyanine). The characteristics of these congener patterns were summarized on the basis of principal component analysis and explanatory variables determined. A Bayesian semifactor model (CMBK2) was applied to the explanatory variables to analyze the sources of PCBs in the sediments. The resulting estimates of the contribution ratio of each kind of sediment indicate that the existence of unidentified sources can be ignored and that the assumed seven sources are adequate to account for the contamination. Within the port, the contribution ratio of KC500 and KC600 (used as paints for ship hulls) was extremely high, but outside the port, the influence of azo pigments was observable to a limited degree. This indicates that environmental PCBs not derived from technical PCBs are present at levels that cannot be ignored.

Observation of gamma ray bursts and flares by the EGRET telescope on the Compton Gamma Ray Observatory

NASA Technical Reports Server (NTRS)

Schneid, E. J.; Bertsch, D. L.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Kwok, P. W.; Mattox, J. R.; Sreekumar, P.; Thompson, D. J.; Kanbach, G.

1992-01-01

The Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory has observed energetic gamma ray bursts and flares. On May 3, 1991, EGRET detected a gamma ray burst both in the energy measuring NaI (Tl) scintillator and independently in the spark chamber imaging assembly. The NaI spectra were accumulated by a special BURST mode of EGRET. The spectra were measured over a range from 1 to 200 MeV, in three sequential spectra of 1,2, and 4 seconds. During the peak of the burst, six individual gamma rays were detected in the spark chamber, allowing a determination of the burst arrival direction. The intense flares of June were also detected. A solar flare on June 4 was observed to last for several minutes and for a brief time, less than a minute, had significant emission of gamma rays exceeding 150 MeV.

Brain cholinesterase activity of nestling great egrets, snowy egrets, and black-crowned night-herons

USGS Publications Warehouse

Custer, T.W.; Ohlendorf, H.M.

1989-01-01

Inhibition of brain cholinesterase (ChE) activity in birds is often used to diagnose exposure or death from organophosphorus or carbmate pesticides. Brain ChE activity in the young of altricial species increase with age; however, this relationship has only been demonstrated in the European starling (Sturnus vulgaris). Brain ChE activity of nestling great egrets (Casmerodius albus) collected from a colony in Texas increased significantly with age and did not differ among individuals from different nests. Brain ChE activity of nestling snowy egrets (Egretta thula) and black-crowned night -herons (Nycticorax nycticorax) collected in one colony each from Rhode Island, Texas, and California also increased significantly with age and did not differ among individuals from different nests or colonies. This study further demonstrates that age must be considered when evaluating exposure of nestling altricial birds to ChE inhibitors.

Brain cholinesterase activity of nestling great egrets snowy egrets and black-crowned night-herons

USGS Publications Warehouse

Custer, T.W.; Ohlendorf, H.M.

1989-01-01

Inhibition of brain cholinesterase (ChE) activity in birds is often used to diagnose exposure or death from organophosphorus or carbamate pesticides. Brain ChE activity in the young of altricial species increases with age; however, this relationship has only been demonstrated in the European starling (Sturnus vulgaris). Brain ChE activity of nestling great egrets (Casmerodius albus) collected from a colony in Texas (USA) increased significantly with age and did not differ among individuals from different nests. Brain ChE activity of nestling snowy egrets (Egretta thula) and black-crowned night-herons (Nycticorax nycticorax) collected in one colony each from Rhode Island, Texas and California (USA) also increased significantly with age and did not differ among individuals from different nests or colonies. This study further demonstrates that age must be considered when evaluating exposure of nestling altricial birds to ChE inhibitors.

Evidence for a New Class of Extreme Ultraviolet Sources

NASA Technical Reports Server (NTRS)

Maoz, Dan; Ofek, Eran O.; Shemi, Amotz

1997-01-01

Most of the sources detected in the extreme ultraviolet (EUV; 100-600 A) by the ROSAT/WFC and EUVE all-sky surveys have been identified with active late-type stars and hot white dwarfs that are near enough to the Earth to escape absorption by interstellar gas. However, about 15 per cent of EUV sources are as yet unidentified with any optical counterparts. We examine whether the unidentified EUV sources may consist of the same population of late-type stars and white dwarfs. We present B and R photometry of stars in the fields of seven of the unidentified EUV sources. We detect in the optical the entire main-sequence and white dwarf population out to the greatest distances where they could still avoid absorption. We use color-magnitude diagrams to demonstrate that, in most of the fields, none of the observed stars has the colours and magnitudes of late-type dwarfs at distances less than 100 pc. Similarly, none of the observed stars is a white dwarf within 500 pc that is hot enough to be a EUV emitter. The unidentified EUV sources we study are not detected in X-rays, while cataclysmic variables, X-ray binaries, and active galactic nuclei generally are. We conclude that some of the EUV sources may be a new class of nearby objects, which are either very faint at optical bands or which mimic the colours and magnitudes of distant late-type stars or cool white dwarfs. One candidate for optically faint objects is isolated old neutron stars, slowly accreting interstellar matter. Such neutron stars are expected to be abundant in the Galaxy, and have not been unambiguously detected.

Looking for blazars in a sample of unidentified high-energy emitting Fermi sources

NASA Astrophysics Data System (ADS)

Marchesini, E. J.; Masetti, N.; Chavushyan, V.; Cellone, S. A.; Andruchow, I.; Bassani, L.; Bazzano, A.; Jiménez-Bailón, E.; Landi, R.; Malizia, A.; Palazzi, E.; Patiño-Álvarez, V.; Rodríguez-Castillo, G. A.; Stephen, J. B.; Ubertini, P.

2016-11-01

Context. Based on their overwhelming dominance among associated Fermi γ-ray catalogue sources, it is expected that a large fraction of the unidentified Fermi objects are blazars. Through crossmatching between the positions of unidentified γ-ray sources from the First Fermi Catalog of γ-ray sources emitting above 10 GeV (1FHL) and the ROSAT and Swift/XRT catalogues of X-ray objects and between pointed XRT observations, a sample of 36 potential associations was found in previous works with less than 15 arcsec of positional offset. One-third of them have recently been classified; the remainder, though believed to belong to the blazar class, still lack spectroscopic classifications. Aims: We study the optical spectrum of the putative counterparts of these unidentified gamma-ray sources in order to find their redshifts and to determine their nature and main spectral characteristics. Methods: An observational campaign was carried out on the putative counterparts of 13 1FHL sources using medium-resolution optical spectroscopy from the Osservatorio Astronomico di Bologna in Loiano, Italy; the Telescopio Nazionale Galileo and the Nordic Optical Telescope, both in the Canary Islands, Spain; and the Observatorio Astronómico Nacional San Pedro Mártir in Baja California, Mexico. Results: We were able to classify 14 new objects based on their continuum shapes and spectral features. Conclusions: Twelve new blazars were found, along with one new quasar and one new narrow line Seyfert 1 (NLS1) to be potentially associated with the 1FHL sources of our sample. Redshifts or lower limits were obtained when possible alongside central black hole mass and luminosity estimates for the NLS1 and the quasar.

How does the presence of a conspecific individual change the behavioral game that a predator plays with its prey?

PubMed

Vardi, Reut; Abramsky, Zvika; Kotler, Burt P; Altstein, Ofir; Rosenzweig, Michael L

2017-07-01

Behavioral games predators play among themselves may have profound effects on behavioral games predators play with their prey. We studied the behavioral game between predators and prey within the framework of social foraging among predators. We tested how conspecific interactions among predators (little egret) change the predator-prey behavioral game and foraging success. To do so, we examined foraging behavior of egrets alone and in pairs (male and female) in a specially designed aviary consisting of three equally spaced pools with identical initial prey (comet goldfish) densities. Each pool was comprised of a risky microhabitat, rich with food, and a safe microhabitat with no food, forcing the fish to trade off food and safety. When faced with two versus one egret, we found that fish significantly reduced activity in the risky habitat. Egrets in pairs suffered reduced foraging success (negative intraspecific density dependence) and responded to fish behavior and to their conspecific by changing their visiting regime at the different pools-having shorter, more frequent visits. The time egret spent on each visit allowed them to match their long-term capture success rate across the environment to their capture success rate in the pool, which satisfies one aspect of optimality. Overall, egrets in pairs allocated more time for foraging and changed their foraging tactics to focus more on fish under cover and fish 'peeping' out from their shelter. These results suggest that both prey and predator show behavioral flexibility and can adjust to changing conditions as needed in this foraging game.

Foraging decisions, patch use, and seasonality in egrets (Aves: ciconiiformes)

USGS Publications Warehouse

Erwin, R.M.

1985-01-01

Feeding snowy (Egretta thula) and great (Casmerodius albus) egrets were observed during 2 breeding seasons in coastal New Jersey and 2 brief winter periods in northeast Florida (USA). A number of tests based on assumptions of foraging models, predictions from foraging theory, and earlier empirical tests concerning time allocation and movement in foraging patches was made. Few of the expectations based on foraging theory and/or assumptions were supported by the empirical evidence. Snowy egrets fed with greater intensity and efficiency during the breeding season (when young were being fed) than during winter. They also showed some tendency to leave patches when their capture rate declined, and they spent more time foraging in patches when other birds were present nearby. Great egrets showed few of these tendencies, although they did leave patches when their intercapture intervals increased. Satiation differences had some influence on feeding rates in snowy egrets, but only at the end of feeding bouts. Some individuals of both species revisited areas in patches that had recently been exploited, and success rates were usually higher after the 2nd visit. Apparently, for predators of active prey, short-term changes in resource availability ('resource depression') may be more important than resource depletion, a common assumption in most optimal foraging theory models.

Lessons from the great egret: Cosmopolitan species as environmental guides

NASA Astrophysics Data System (ADS)

Lewis, Celia

This dissertation is an experiment in environmental learning. The cosmopolitan species, the great egret (Egretta alba), is used as a guide to learning about local environmental history and local ecology in four places: Long Island Sound, USA; Delaware Bay, USA; Neusiedler See, Austria; and the Hunter River Valley in New South Wales, Australia. It is also used as a guide to the development of a cosmopolitan environmental perspective. The development of this broad perspective is based on the thesis that knowledge of the ecology of species mobility and cosmopolitanism may bring to light ecological connections within and between places, and that human migration and cultural mobility are also part of the ecological history of the environment. The concept of species guides is reviewed in nature literature, including examples from the works of Richard Nelson, Robert Michael Pyle, Terry Tempest Williams, Scott Weidensaul, and Peter Matthiessen. The author visits egret colonies, interviews biologists working at these sites, and develops narratives about the environmental history and the cultural history of each site, and the connections between egrets and humans in those places. Parallels are drawn between the migrant and cosmopolitan nature of great egrets and other species, and of the human species, and how recognition of these similarities can lead to a cosmopolitan environmental perspective.

VizieR Online Data Catalog: Observation of first Fermi-LAT sources at Parkes (Camilo+, 2015)

NASA Astrophysics Data System (ADS)

Camilo, F.; Kerr, M.; Ray, P. S.; Ransom, S. M.; Sarkissian, J.; Cromartie, H. T.; Johnston, S.; Reynolds, J. E.; Wolff, M. T.; Freire, P. C. C.; Bhattacharyya, B.; Ferrara, E. C.; Keith, M.; Michelson, P. F.; Parkinson, P. M. S.; Wood, K. S.

2017-10-01

Keith et al. (2011MNRAS.414.1292K) used a digital filterbank at Parkes to search 11 unidentified sources from the first Fermi-LAT catalog (1FGL; Abdo et al. 2010, J/ApJS/188/405). Two MSPs and one slow pulsar were discovered in single observations of each target at a central frequency of 1.4 GHz. Subsequently, one of these MSPs was found to be associated with the corresponding LAT source. At nearly the same time, in late 2009, we used an analog filterbank at Parkes to search 14 unidentified 1FGL sources (Kerr et al. 2012ApJ...748L...2K). The single observations of these targets resulted in the detection of six MSPs, five of them discoveries. However, confirmation of some of these MSPs was not easy: the search observations lasted for 1-2 hr each, but some of the pulsars were not detected in equivalent initial confirmation attempts, owing to the effects of interstellar scintillation. These and other selection effects (see Section 2.2 for details) led us to search some promising unidentified LAT sources repeatedly. (1 data file).

Unidentified Flying Objects (UFOs). LC Science Tracer Bullet.

ERIC Educational Resources Information Center

Library of Congress, Washington, DC. Science and Technology Div.

This guide lists information sources dealing with unidentified flying objects (UFOs). Not meant to be a comprehensive bibliography, this compilation is designed--as the name of the series implies--to put the reader "on target." Included are: (1) subject headings used by the Library of Congress, under which publications on this subject…

Organochlorine pesticide, polychlorinated biphenyl, trace element and metal residues in bird eggs from Salton Sea, California, 2004

USGS Publications Warehouse

Henny, Charles J.; Anderson, T.W.; Crayon, J.J.

2008-01-01

The Salton Sea is a highly eutrophic, hypersaline terminal lake that receives inflows primarily from agricultural drainages in the Imperial and Coachella valleys. Impending reductions in water inflow at Salton Sea may concentrate existing contaminants which have been a concern for many years, and result in higher exposure to birds. Thus, waterbird eggs were collected and analyzed in 2004 and compared with residue concentrations from earlier years; these data provide a base for future comparisons. Eggs from four waterbird species (black-crowned night-heron [Nycticorax nycticorax], great egret [Ardea alba], black-necked stilt [Himantopus mexicanus], and American avocet [Recurvirostra Americana]) were collected. Eggs were analyzed for organochlorine pesticides, polychlorinated biphenyls (PCBs), metals, and trace elements, with current results compared to those reported for eggs collected from the same species and others during 1985a??1993. The two contaminants of primary concern were p,pa??-DDE (DDE) and selenium. DDE concentrations in night-heron and great egret eggs collected from the northwest corner of Salton Sea (Whitewater River delta) decreased 91 and 95%, respectively, by 2004, with a concomitant increase in eggshell thickness for both species. Decreases in bird egg DDE levels paralleled those in tissues of tilapia (Oreochromis mossambicus ?? O. urolepis), an important prey species for herons and egrets. Despite most nests of night-herons and great egrets failing in 2004 due to predation, predicted reproductive effects based on DDE concentrations in eggs were low or negligible for these species. The 2004 DDE findings were in dramatic contrast to those in the past decade, and included an 81% decrease in black-necked stilt eggs, although concentrations were lower historically than those reported in night-herons and egrets. Selenium concentrations in black-necked stilt eggs from the southeast corner of Salton Sea (Davis Road) were similar in 1993 and 2004, with 4.5a??7.6% of the clutches estimated to be selenium impaired during both time periods. Because of present selenium concentrations and future reduced water inflow, the stilt population is of special concern. Between 1992 and 1993 and 2004 selenium in night-heron and great egret eggs from the Whitewater River delta at the north end of the Sea decreased by 81 and 55%, respectively. None of the night-heron or egret eggs collected in 2004 contained selenium concentrations above the lowest reported effect concentration (6.0 I?g/g dw). Reasons for selenium decreases in night-heron and egret eggs are unknown. Other contaminants evaluated in 2004 were all below known effect concentrations. However, in spite of generally low contaminant levels in 2004, the nesting populations of night-herons and great egrets at Salton Sea were greatly reduced from earlier years and snowy egrets (Egretta thula) were not found nesting. Other factors that include predation, reduced water level, diminished roost and nest sites, increased salinity, eutrophication, and reduced fish populations can certainly influence avian populations. Future monitoring, to validate predicted responses by birds, other organisms, and contaminant loadings associated with reduced water inflows, together with adaptive management should be the operational framework at the Salton Sea.

High energy variability of 3C 273 during the AGILE multiwavelength campaign of December 2007-January 2008

NASA Astrophysics Data System (ADS)

Pacciani, L.; Donnarumma, I.; Vittorini, V.; D'Ammando, F.; Fiocchi, M. T.; Impiombato, D.; Stratta, G.; Verrecchia, F.; Bulgarelli, A.; Chen, A. W.; Giuliani, A.; Longo, F.; Pucella, G.; Vercellone, S.; Tavani, M.; Argan, A.; Barbiellini, G.; Boffelli, F.; Caraveo, P. A.; Cattaneo, P. W.; Cocco, V.; Costa, E.; Del Monte, E.; Di Cocco, G.; Evangelista, Y.; Feroci, M.; Froysland, T.; Fuschino, F.; Galli, M.; Gianotti, F.; Labanti, C.; Lapshov, I.; Lazzarotto, F.; Lipari, P.; Marisaldi, M.; Mereghetti, S.; Morselli, A.; Pellizzoni, A.; Perotti, F.; Picozza, P.; Prest, M.; Rapisarda, M.; Soffitta, P.; Trifoglio, M.; Tosti, G.; Trois, A.; Vallazza, E.; Zanello, D.; Antonelli, L. A.; Colafrancesco, S.; Cutini, S.; Gasparrini, D.; Giommi, P.; Pittori, C.; Salotti, L.

2009-01-01

Context: We report the results of a 3-week multi-wavelength campaign targeting the flat spectrum radio quasar 3C 273 carried out with the AGILE gamma-ray mission, covering the 30 MeV-50 GeV and 18-60 keV, the REM observatory (covering the near-IR and optical), Swift (near-UV/Optical, 0.2-10 keV and 15-50 keV), INTEGRAL (3-200 keV) and Rossi XTE (2-12 keV). This is the first observational campaign including gamma-ray data, after the last EGRET observations, more than 8 years ago. Aims: This campaign has been organized by the AGILE team with the aim of observing, studying and modelling the broad band energy spectrum of the source, and its variability on a week timescale, testing the emission models describing the spectral energy distribution of this source. Methods: Our study was carried out using simultaneous light curves of the source flux from all the involved instruments, in the different energy ranges, to search for correlated variability. Then a time-resolved spectral energy distribution was used for a detailed physical modelling of the emission mechanisms. Results: The source was detected in gamma-rays only in the second week of our campaign, with a flux comparable to the level detected by EGRET in June 1991. We found an indication of a possible anti-correlation between the emission at gamma-rays and at soft and hard X-rays, supported by the complete set of instruments. Instead, optical data do not show short term variability, as expected for this source. Only in two preceding EGRET observations (in 1993 and 1997) 3C 273 showed intra-observation variability in gamma-rays. In the 1997 observation, flux variation in gamma-rays was associated with a synchrotron flare. The energy-density spectrum with almost simultaneous data partially covers the regions of synchrotron emission, the big blue bump, and the inverse-Compton. We adopted a leptonic model to explain the hard X/gamma-ray emissions, although from our analysis hadronic models cannot be ruled out. In the adopted model, the soft X-ray emission is consistent with combined synchrotron-self Compton and external Compton mechanisms, while hard X and gamma-ray emissions are compatible with external Compton from thermal photons of the disk. Under this model, the time evolution of the spectral energy distribution is well interpreted and modelled in terms of an acceleration episode of the electron population, leading to a shift in the inverse Compton peak towards higher energies.

X-ray Studies of Unidentified Galactic TeV Gamma-ray Sources

NASA Astrophysics Data System (ADS)

Pühlhofer, Gerd

2009-05-01

Many of the recently discovered Galactic TeV sources remain unidentified to date. A large fraction of the sources is possibly associated with relic pulsar wind nebula (PWN) systems. One key question here is the maximum energy (beyond TeV) attained in the compact PWNe. Hard X-ray emission can trace those particles, but current non-focussing X-ray instruments above 10 keV have difficulties to deconvolve the hard pulsar spectrum from its surrounding nebula. Some of the new TeV sources are also expected to originate from middle-aged and possibly even from old supernova remnants (SNR). But no compelling case for such an identification has been found yet. In established young TeV-emitting SNRs, X-ray imaging above 10 keV could help to disentangle the leptonic from the hadronic emission component in the TeV shells, if secondary electrons produced in hadronic collisions can be effectively detected. As SNRs get older, the high energy electron component is expected to fade away. This may allow to verify the picture through X-ray spectral evolution of the source population. Starting from the lessons we have learned so far from X-ray follow-up observations of unidentified TeV sources, prospects for Simbol-X to resolve open questions in this field will be discussed.

5th Annual AGILE Science Workshop

NASA Technical Reports Server (NTRS)

Hunter, Stanley

2008-01-01

The EGRET model of the galactic diffuse gamma-ray emission (GALDIF) has been extended to provide full-sky coverage and improved to address the discrepancies with the EGRET data. This improved model is compared with the AGILE results from the Galactic center. The comparison is discussed.

Fermi Large Area Telescope Measurements of the Diffuse Gamma-Ray Emission at Intermediate Galactic Latitudes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdo, A.A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.

The diffuse galactic {gamma}-ray emission is produced by cosmic rays (CRs) interacting with the interstellar gas and radiation field. Measurements by the Energetic Gamma-Ray Experiment Telescope (EGRET) instrument on the Compton Gamma-Ray Observatory indicated excess {gamma}-ray emission {ge}1 GeV relative to diffuse galactic {gamma}-ray emission models consistent with directly measured CR spectra (the so-called 'EGRET GeV excess'). The Large Area Telescope (LAT) instrument on the Fermi Gamma-Ray Space Telescope has measured the diffuse {gamma}-ray emission with improved sensitivity and resolution compared to EGRET. We report on LAT measurements for energies 100 MeV to 10 GeV and galactic latitudes 10{sup o}more » {le} |b| {le} 20{sup o}. The LAT spectrum for this region of the sky is well reproduced by a diffuse galactic {gamma}-ray emission model that is consistent with local CR spectra and inconsistent with the EGRET GeV excess.« less

Fermi Large Area Telescope Measurements of the Diffuse Gamma-Ray Emission at Intermediate Galactic Latitudes

DOE PAGES

Abdo, A. A.; Ackermann, M.; Ajello, M.; ...

2009-12-16

We report that the diffuse galactic γ-ray emission is produced by cosmic rays (CRs) interacting with the interstellar gas and radiation field. Measurements by the Energetic Gamma-Ray Experiment Telescope (EGRET) instrument on the Compton Gamma-Ray Observatory indicated excess γ-ray emission ≳1 GeV relative to diffuse galactic γ-ray emission models consistent with directly measured CR spectra (the so-called “EGRET GeV excess”). The Large Area Telescope (LAT) instrument on the Fermi Gamma-Ray Space Telescope has measured the diffuse γ -ray emission with improved sensitivity and resolution compared to EGRET. We report on LAT measurements for energies 100 MeV to 10 GeV andmore » galactic latitudes 10° ≤ | b | ≤ 20°. Finally, the LAT spectrum for this region of the sky is well reproduced by a diffuse galactic γ-ray emission model that is consistent with local CR spectra and inconsistent with the EGRET GeV excess.« less

Fermi large area telescope measurements of the diffuse gamma-ray emission at intermediate galactic latitudes.

PubMed

Abdo, A A; Ackermann, M; Ajello, M; Anderson, B; Atwood, W B; Axelsson, M; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Baughman, B M; Bechtol, K; Bellazzini, R; Berenji, B; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Bregeon, J; Brez, A; Brigida, M; Bruel, P; Burnett, T H; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Cecchi, C; Charles, E; Chekhtman, A; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Conrad, J; Dereli, H; Dermer, C D; de Angelis, A; de Palma, F; Digel, S W; Di Bernardo, G; Dormody, M; do Couto e Silva, E; Drell, P S; Dubois, R; Dumora, D; Edmonds, Y; Farnier, C; Favuzzi, C; Fegan, S J; Focke, W B; Frailis, M; Fukazawa, Y; Funk, S; Fusco, P; Gaggero, D; Gargano, F; Gehrels, N; Germani, S; Giebels, B; Giglietto, N; Giordano, F; Glanzman, T; Godfrey, G; Grenier, I A; Grondin, M-H; Grove, J E; Guillemot, L; Guiriec, S; Hanabata, Y; Harding, A K; Hayashida, M; Hays, E; Hughes, R E; Jóhannesson, G; Johnson, A S; Johnson, R P; Johnson, T J; Johnson, W N; Kamae, T; Katagiri, H; Kataoka, J; Kawai, N; Kerr, M; Knödlseder, J; Kocian, M L; Kuehn, F; Kuss, M; Lande, J; Latronico, L; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Madejski, G M; Makeev, A; Mazziotta, M N; McConville, W; McEnery, J E; Meurer, C; Michelson, P F; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nolan, P L; Nuss, E; Ohsugi, T; Okumura, A; Omodei, N; Orlando, E; Ormes, J F; Paneque, D; Panetta, J H; Parent, D; Pelassa, V; Pepe, M; Pesce-Rollins, M; Piron, F; Porter, T A; Rainò, S; Rando, R; Razzano, M; Reimer, A; Reimer, O; Reposeur, T; Ritz, S; Rodriguez, A Y; Roth, M; Ryde, F; Sadrozinski, H F-W; Sanchez, D; Sander, A; Saz Parkinson, P M; Scargle, J D; Sellerholm, A; Sgrò, C; Smith, D A; Smith, P D; Spandre, G; Spinelli, P; Starck, J-L; Stecker, F W; Striani, E; Strickman, M S; Strong, A W; Suson, D J; Tajima, H; Takahashi, H; Tanaka, T; Thayer, J B; Thayer, J G; Thompson, D J; Tibaldo, L; Torres, D F; Tosti, G; Tramacere, A; Uchiyama, Y; Usher, T L; Vasileiou, V; Vilchez, N; Vitale, V; Waite, A P; Wang, P; Winer, B L; Wood, K S; Ylinen, T; Ziegler, M

2009-12-18

The diffuse galactic gamma-ray emission is produced by cosmic rays (CRs) interacting with the interstellar gas and radiation field. Measurements by the Energetic Gamma-Ray Experiment Telescope (EGRET) instrument on the Compton Gamma-Ray Observatory indicated excess gamma-ray emission greater, > or approximately equal to 1 GeV relative to diffuse galactic gamma-ray emission models consistent with directly measured CR spectra (the so-called "EGRET GeV excess"). The Large Area Telescope (LAT) instrument on the Fermi Gamma-Ray Space Telescope has measured the diffuse gamma-ray emission with improved sensitivity and resolution compared to EGRET. We report on LAT measurements for energies 100 MeV to 10 GeV and galactic latitudes 10 degrees < or = |b| < or = 20 degrees. The LAT spectrum for this region of the sky is well reproduced by a diffuse galactic gamma-ray emission model that is consistent with local CR spectra and inconsistent with the EGRET GeV excess.

Residue levels of organochlorines and mercury in Cattle Egret, Bubulcus ibis, eggs from the Faiyum Oasis, Egypt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mullie, W.C.; Massi, A.; Focardi, S.

1992-05-01

In Egypt, the Cattle Egret Bubulcus ibis is a common resident bird of the Nile Valley, the southern part of the Nile Delta, and the Suez Canal area. In the 1970s it disappeared as a breeding bird from the greater part of the Nile Delta, as did several other bird species, notably birds of prey. Only in recent years some of the species that had declined are markedly recovering, such as the Black-shouldered Kite Elanus caeruleus and the Cattle Egret. There is circumstancial evidence that these birds declined - at least partially - as a result of pesticide use inmore » the main cotton growing areas, but this has never been substantiated. The recent recovery of some bird populations, commencing in the 1980s, coincides with a general shift from the use of organochlorines (except for endrin and HCH which are still in use) towards synthetic pyrethroids, organophosphates and carbamates in Egyptian agriculture: 30 million kg of formulated product annually, of which 70% are applied to cotton. The number of breeding pairs of Cattle Egrets in a well-known colony at Giza (30[degrees].01'N 31[degrees].13'E) steadily declined from 2500 in 1977 to 1100 in 1984. Therefore, it was decided to collect some eggs for residue analysis. Cattle Egrets are not piscivores, such as most other egrets, but mainly insectivores. They feed in agricultural areas and likely are good indicators for pesticide use in these habitats. Based on gizzard contents analysis, Kirkpatrick (1925) concluded that Cattle Egrets in Egypt only occasionally take (semi) aquatic prey, such as toads, and further predominantly Orthoptera and Diptera on arable land. Various studies have been published with respect to pesticides or heavy metals in the Egyptian environment but, surprisingly, birds have been almost completely ignored. The data presented are the first residue analyses of bird eggs from an agricultural area in Egypt, and as such they can be considered as baseline data for future research. 36 refs., 2 tabs.« less

IR observations in gamma-ray blazars

NASA Technical Reports Server (NTRS)

Mahoney, W. A.; Gautier, T. N.; Ressler, M. E.; Wallyn, P.; Durouchoux, P.; Higdon, J. C.

1997-01-01

The infrared photometric and spectral observation of five gamma ray blazars in coordination with the energetic gamma ray experiment telescope (EGRET) onboard the Compton Gamma Ray Observatory is reported. The infrared measurements were made with a Cassegrain infrared camera and the mid-infrared large well imager at the Mt. Palomar 5 m telescope. The emphasis is on the three blazars observed simultaneously by EGRET and the ground-based telescope during viewing period 519. In addition to the acquisition of broadband spectral measurements for direct correlation with the 100 MeV EGRET observations, near infrared images were obtained, enabling a search for intra-day variability to be carried out.

ADVANTAGES AND DISADVANTAGES OF EGRET AND HERON BROOD REDUCTION.

PubMed

Mock, Douglas W; Parker, Geoffrey A

1986-05-01

Data from great egrets and great blue herons were used to test a fundamental assumption of Lack's brood-reduction hypothesis, that mortality is brood-size dependent. This was confirmed for the largest brood sizes (4 and 3), which, in egrets, also have the highest sib-fighting rates. Broods of one, however, experienced paradoxically high mortality, especially early in the season. The hypothesis is advanced that parents desert unprofitably small broods when sufficient time remains for production of a larger brood. A simple game-theory model shows that this parental desertion may hinge primarily on the overall costs of renesting. Egret brood reduction caused by sibling aggression (siblicide) occurred later than less aggressive forms of brood reduction. The inclusive fitness of senior broodmates is maximized by the successful fledging of all sibs, and the physical superiority of seniors (in food-handling for herons; food-handling and aggression for egrets) usually suffices to guarantee their own welfare in brood competitions. Finally, it is shown that the last chick in asynchronously hatching broods represents two kinds of reproductive value (RV) to the parents-"extra RV" (obtained despite the survival of elder sibs) and "insurance RV" (obtained only when at least one elder sib dies first)-which can be distinguished from field data. This approach can be used in comparisons with other asynchronous species for partitioning the fitness contributions of marginal offspring. © 1986 The Society for the Study of Evolution.

Changes in the nesting populations of colonial waterbirds in Jamaica Bay Wildlife Refuge, New York, 1974-1998

USGS Publications Warehouse

Brown, K.M.; Tims, J.L.; Erwin, R.M.; Richmond, M.E.

2001-01-01

The Jamaica Bay Wildlife Refuge (JBWR) represents the largest protected area for over 300 species of migratory and resident birds on Long Island (LI), New York, and occupies a key position along the Atlantic flyway. We identified changes in nesting populations for 18 species of colonial waterbirds in JBWR and on LI, during 1974 - 1998, to provide a basis for future wildlife management decisions in JBWR and also at nearby John F. Kennedy International Airport. None of the populations was stable over the past 25 years in JBWR or on LI. Some populations in JBWR increased (Laughing Gull L. atricilla Linnaeus, Great Black-backed Gull L. marinus Linnaeus, Forster's Tern Sterna forsteri Nuttall) while others decreased (Herring Gull Larus argentatus Coues, Snowy Egret Egretta thula Molina), but only Cattle Egrets (Bubulcus ibis Linnaeus) have disappeared from the refuge. Common Tern (S. hitundo Linnaeus), Least Tern (S. antillarum Lesson), Roseate Tern (S. dougallii Montagu), Black Skimmer (Rynchops niger Linnaeus), Black-crowned Night Heron (Nycticorax nycticorax Linnaeus) and Great Egret (Ardea alba Linnaeus) populations all increased on LI over the sampling period although the Common Tern colonies in JBWR have been declining since 1986. The continued protection of the colony sites, particularly saltmarsh islands, in JBWR will be important to the conservation efforts of many colonial waterbird populations on Long Island. The JBWR colonies may serve as a source of emigrants to other Long Island colonies, and in some cases, act as a 'sink' for birds immigrating from New Jersey and elsewhere.

Avian Influenza Virus Surveillance in South-Central Spain Using Fecal Samples of Aquatic Birds Foraging at Landfills

PubMed Central

Bárbara, Andreia; Torrontegi, Olalla; Camacho, Maria-Cruz; Barral, Marta; Hernández, Jose-Manuel; Höfle, Ursula

2017-01-01

Aquatic wild birds have been intensively studied to better understand their role in avian influenza virus (AIV) maintenance and spread. To date, AIV surveillance has primarily focused on natural aquatic environments where different bird species aggregate and viral survival is enhanced. However, artificial habitats such as landfills are attracting substantial numbers of wild birds, AIV reservoir species included. The use of landfills as a predictable food source has significantly influenced population size, migratory traits, and feeding behavior of white storks (Ciconia ciconia) and black-headed gulls (Chroicocephalus ridibundus) among others. Considering the proximity of landfills to urban settlements and frequently poultry-farms, targeted monitoring of AIV in bird species that forage at landfills but are known to also frequent urban and agricultural habitats could be a useful means for monitoring of AIV, especially during periods of bird aggregation. During the wintering season 2014–2015, the prevalence of AIV in five avian species at two landfills in South-Central Spain was explored by rRT-PCR and species related temporal variation in AIV prevalence determined. We collected and tested 1,186 fresh fecal samples from white storks (N = 689), cattle egrets (Bubulcus ibis, N = 116) and mixed flocks of gulls (N = 381) as well as cloacal and oral swabs from five birds found dead. Seven samples contained AIV, five from gulls and one each from a stork and a cattle egret. Overall, AIV prevalence was 0.60%. No significant temporal variation was observed in AIV prevalence. Prevalence differed significantly among the sampled taxonomic groups, being highest in gulls (1.31%). H16N3 subtype was detected from a cattle egret and H11N9 subtype from a white stork, whereas gulls harbored both subtypes in addition to H11N3 subtype. H16 subtype detection in a cattle egret evidences its host range may not be restricted to gulls. Our results indicate that wild birds foraging at landfills may carry different LPAIV subtypes. PMID:29124060

Obituary: Patrick L. Nolan (1952-2011)

NASA Astrophysics Data System (ADS)

Digel, Seth

2011-12-01

Patrick Lee Nolan died at his home in Palo Alto, California, on November 6, 2011, from complications related to a brain tumor, glioblastoma multiforme, which had been diagnosed less than five months earlier. He was born in Colusa, California, on November 18, 1952. Pat was the only child of John Henry Nolan and Carol Lee Harris Nolan. For most of his childhood they lived in Grass Valley, California, where his father was a butcher and his mother was a surgical nurse. Pat graduated from the California Institute of Technology in 1974 with a B.S. in Physics and completed a Ph.D. at the University of California at San Diego in 1982. His graduate and professional career was devoted to high-energy astronomy. His loss is being keenly felt by his friends and colleagues around the world, including the members of the Chancel Choir of the Menlo Park Presbyterian Church, of which he was a member for 25 years. At U. C. San Diego, Pat worked on construction of the Hard X-ray and Low Energy Gamma Ray Experiment for the first High Energy Astronomy Observatory mission, which was launched in 1977. His Ph.D. thesis, supervised by Prof. Laurence E. Peterson, was based on data from this instrument and addressed variability of the high-energy emission from Cygnus X-1 and other black hole binary systems in the Milky Way. After he completed his Ph.D., Pat took a National Research Council postdoctoral research position at the Naval Research Laboratory in Washington, D.C. He worked there from 1982-1984 developing spectral analysis software and studying gamma-ray bursts using the gamma-ray spectrometer on the Solar Maximum Mission satellite. A paper in Nature setting constraining limits on positron-electron annihilation radiation in the spectra of bursts marked the culmination of his efforts. Pat was hired by Prof. Robert Hofstadter at Stanford University in 1984 to work on the Energetic Gamma-Ray Experiment Telescope (EGRET). As a co-investigator for EGRET, Pat worked on its calorimeter subsystem, including calibration at the Stanford Linear Accelerator Center (SLAC), as well as on data analysis software and methods. EGRET was carried into space by the Shuttle Atlantis in 1991 as part of the Compton Gamma Ray Observatory. He led analyses of gamma-ray pulsars and other astrophysical sources, including a major study of EGRET source variability, and he was a valued resource to the many EGRET graduate students at Stanford. Members of the EGRET team regularly turned to Pat for advice on statistical analysis issues. After the launch of the Compton Observatory, Pat became a member of a small group at Stanford University and SLAC that developed and promoted a new design for a next-generation gamma-ray telescope, based on modern solid-state detectors for particle physics detectors. The concept became the Gamma-ray Large Area Space Telescope mission, which was launched by NASA in 2008 and renamed the Fermi Gamma-ray Space Telescope. The scientific collaboration for the Large Area Telescope on Fermi has grown to about 400 members from a number of countries. Pat was a recognized expert in statistics and data analysis within the collaboration and as a member of the Publication Board developed the Web and database systems for internal review of scientific publications. Pat was unassuming, widely read, and knowledgeable in many fields. These qualities together with his quiet joy in science made him a valued friend and colleague to many. At the time of his death, Pat was a Senior Research Physicist in the Hansen Experimental Physics Laboratory at Stanford University.

The EGRET data products

NASA Technical Reports Server (NTRS)

Mattox, J. R.; Bertsch, D. L.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Kwok, P. W.; Lin, Y. C.; Mayer-Hasselwander, H. A.

1992-01-01

We describe the Energetic Gamma Ray Experiment Telescope (EGRET) data products which we anticipate will suffice for virtually all guest and archival investigations. The production process, content, availability, format, and the associated software of each product is described. Supplied here is sufficient detail for each researcher to do analysis which is not supported by extant software.

A white pelican and egrets in the Merritt Island National Wildlife Refuge

NASA Technical Reports Server (NTRS)

1999-01-01

A white pelican and several small egrets rest on the bank of a pond in in the waters of the Merritt Island National Wildlife Refuge, which shares a boundary with Kennedy Space Center. White pelicans inhabit marshy lakes and along the Pacific and Texas coasts. They winter from Florida and southern California south to Panama, chiefly in coastal lagoons. They are frequently seen flying in long lines, flapping and sailing in unison, but also ride rising air currents to soar gracefully in circles. The range of the egret includes southern and eastern states, Mexico, Central and South America, and the West Indies. The Refuge encompasses 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects.

Concerning sources of O/1D/ in Aurora - Electron impact and dissociative recombination

NASA Technical Reports Server (NTRS)

Sharp, W. E.; Ortland, D.; Cageao, R.

1983-01-01

The present investigation is concerned with two questions. One is related to the possibility that the O(1D) level is produced by an as yet unidentified process in aurora. The second question is concerned with the need for an additional source and the altitude over which it is required. The data base of the AE satellite (AE-D in particular) was examined for this study. It is found that dissociative recombination and electron impact are inadequate sources of O(1D) in aurora. Nearly 90% of the source function is unidentified below 200 km and about 55% is missing above 250 km. The possibility that thermal electron impact could provide the missing source above 250 km was examined. Calculations showed that the missing source above 250 km could be explained by thermal electron impact if the electron temperatures were approximately 2900 K.

The nature of fifty Palermo Swift-BAT hard X-ray objects through optical spectroscopy

NASA Astrophysics Data System (ADS)

Rojas, A. F.; Masetti, N.; Minniti, D.; Jiménez-Bailón, E.; Chavushyan, V.; Hau, G.; McBride, V. A.; Bassani, L.; Bazzano, A.; Bird, A. J.; Galaz, G.; Gavignaud, I.; Landi, R.; Malizia, A.; Morelli, L.; Palazzi, E.; Patiño-álvarez, V.; Stephen, J. B.; Ubertini, P.

2017-07-01

We present the nature of 50 unidentified hard X-ray emitting objects detected with Swift-BAT and listed as of unidentified nature in the 54-month Palermo BAT catalogue. We found 45 extragalactic sources: 26 type 1 AGN, 15 type 2 AGN, one type 1 QSO, one starburst galaxy, one X-ray bright optically normal galaxy, and one LINER. We report 30 new redshift measurements, 13 confirmations and 2 more accurate redshift values. The remaining five objects are galactic sources: three are Cataclismic Variables, one is a X-ray Binary, and one is an active star.

Gamma-Ray Observations of Supernova Remnants

NASA Astrophysics Data System (ADS)

Buckley, James

2000-04-01

Despite the growing evidence for shock acceleration of electrons in supernova remnants (SNR), there is still no direct evidence pointing unambiguously to SNR as sources of cosmic-ray nuclei. Observations of nonthermal synchrotron emission in the limbs of a number of shell-type SNR (SN1006, Tycho, Cas A, IC443, RCW86, and Kepler) provide convincing evidence for acceleration of electrons to energies greater than 10 TeV (Allen 1999). The CANGAROO group has now reported significant VHE gamma-ray emission from SN1006 (Tanimori et al. 1998) and RXJ1713-3946, and the HEGRA group has reported preliminary evidence for TeV emission from Cas A (Pülhofer et al. 1999); all of these measurements are consistent with the expected level of inverse-Compton emission in these objects. Following the predictions of an observable π^0-decay signal from nearby SNRs (e.g., Drury, Aharonian and Volk 1994) the discovery of >100 MeV emission from the direction of a number of SNR by the EGRET experiment (Esposito et al. 1996) and possible evidence for a π^0 component (Gaisser, Protheroe and Stanev 1996) led to some initial optimism that evidence for a SNR origin of cosmic-ray nuclei had been obtained. However, 200 GeV to 100 TeV measurements revealed no significant emission implying either a significantly steeper source spectrum than the canonical ~ E-2.1, a spectral cutoff below the knee energy in these sources, or that a re-interpretation of the EGRET results was required. I will discuss these results, as well as the considerable promise of future gamma-ray experiments to determine the sources of galactic cosmic-ray nuclei and to provide quantitative information about the acceleration mechanisms.

Egg size and laying order of snowy egrets, great egrets, and black-crowned night-herons

USGS Publications Warehouse

Custer, T.W.; Frederick, P.C.

1990-01-01

The nesting biology of the family Ardeidae (bitterns, herons, and egrets) has been intensively studied (e.g., Owen 1960, Milstein et al. 1970, Werschkul 1979), but egg size in relation to laying order bas not received attention. The last egg laid in gull and tern clutches is generally smaller than preceding eggs (e.g., Parsons 1970, Nisbet 1978). The relative size of the final egg in a clutch decreases with increased body size among bird species and this relationship may be correlated with an increased brood-reduction strategy (Slagsvold et al. 1984). Relative egg size could be an important component to brood reduction, because egg size can affect subsequent survival of young (Parsons 1970, Nisbet 1978, Lundberg and Vaisanen 1979).

GRO/EGRET data analysis software: An integrated system of custom and commercial software using standard interfaces

NASA Technical Reports Server (NTRS)

Laubenthal, N. A.; Bertsch, D.; Lal, N.; Etienne, A.; Mcdonald, L.; Mattox, J.; Sreekumar, P.; Nolan, P.; Fierro, J.

1992-01-01

The Energetic Gamma Ray Telescope Experiment (EGRET) on the Compton Gamma Ray Observatory has been in orbit for more than a year and is being used to map the full sky for gamma rays in a wide energy range from 30 to 20,000 MeV. Already these measurements have resulted in a wide range of exciting new information on quasars, pulsars, galactic sources, and diffuse gamma ray emission. The central part of the analysis is done with sky maps that typically cover an 80 x 80 degree section of the sky for an exposure time of several days. Specific software developed for this program generates the counts, exposure, and intensity maps. The analysis is done on a network of UNIX based workstations and takes full advantage of a custom-built user interface called X-dialog. The maps that are generated are stored in the FITS format for a collection of energies. These, along with similar diffuse emission background maps generated from a model calculation, serve as input to a maximum likelihood program that produces maps of likelihood with optional contours that are used to evaluate regions for sources. Likelihood also evaluates the background corrected intensity at each location for each energy interval from which spectra can be generated. Being in a standard FITS format permits all of the maps to be easily accessed by the full complement of tools available in several commercial astronomical analysis systems. In the EGRET case, IDL is used to produce graphics plots in two and three dimensions and to quickly implement any special evaluation that might be desired. Other custom-built software, such as the spectral and pulsar analyses, take advantage of the XView toolkit for display and Postscript output for the color hard copy. This poster paper outlines the data flow and provides examples of the user interfaces and output products. It stresses the advantages that are derived from the integration of the specific instrument-unique software and powerful commercial tools for graphics and statistical evaluation. This approach has several proven advantages including flexibility, a minimum of development effort, ease of use, and portability.

STS-37 Gamma Ray Observatory (GRO) grappled by RMS

NASA Image and Video Library

1991-04-07

Backdropped against the Earth's surface, the Gamma Ray Observatory (GRO) with its solar array (SA) panels deployed is grappled by the remote manipulator system (RMS) during STS-37 systems checkout. GRO's four complement instruments are visible: the Energetic Gamma Ray Experiment Telescope (EGRET) (at the bottom); the Imaging Compton Telescope (COMPTEL) (center); the Oriented Scintillation Spectrometer Experiment (OSSE) (top); and Burst and Transient Source Experiment (BATSE) (on four corners). The view was taken by STS-37 crew through an aft flight deck overhead window.

KSC-99pp0256

NASA Image and Video Library

1999-03-01

KENNEDY SPACE CENTER, FLA. -- A snowy egret wades the shallow waters of the Merritt Island National Wildlife Refuge, which shares a boundary with Kennedy Space Center. Ranging from northern California, Oklahoma and Maine to southern South America, the snowy egret winters north to California and South Carolina. In the East, they are best known as salt marsh birds. Once an endangered species, their numbers have increased again. The 92,000-acre refuge is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Butt, Y M; Romero, G E; Torres, D F

We suggest that ultraluminous X-ray sources (ULXs) and some of the variable low latitude EGRET gamma-ray sources may be two different manifestations of the same underlying phenomena: high-mass microquasars with relativistic jets forming a small angle with the line of sight (i.e. microblazars). Microblazars with jets formed by relatively cool plasma (Lorentz factors for the leptons up to a few hundreds) naturally lead to ULXs. If the jet contains very energetic particles (high-energy cutoff above Lorentz factors of several thousands) the result is a relatively strong gamma-ray source. As pointed out by Kaufman Bernads, Romero & Mirabel (2002), a gamma-raymore » microblazar will always have an X-ray counterpart (although it might be relatively weak), whereas X-ray microblazars might have no gamma-ray counterparts.« less

UNVEILING THE NATURE OF THE UNIDENTIFIED GAMMA-RAY SOURCES. V. ANALYSIS OF THE RADIO CANDIDATES WITH THE KERNEL DENSITY ESTIMATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Massaro, F.; Funk, S.; D'Abrusco, R.

2013-11-01

Nearly one-third of the γ-ray sources detected by Fermi are still unidentified, despite significant recent progress in this area. However, all of the γ-ray extragalactic sources associated in the second Fermi-LAT catalog have a radio counterpart. Motivated by this observational evidence, we investigate all the radio sources of the major radio surveys that lie within the positional uncertainty region of the unidentified γ-ray sources (UGSs) at a 95% level of confidence. First, we search for their infrared counterparts in the all-sky survey performed by the Wide-field Infrared Survey Explorer (WISE) and then we analyze their IR colors in comparison withmore » those of the known γ-ray blazars. We propose a new approach, on the basis of a two-dimensional kernel density estimation technique in the single [3.4] – [4.6] – [12] μm WISE color-color plot, replacing the constraint imposed in our previous investigations on the detection at 22 μm of each potential IR counterpart of the UGSs with associated radio emission. The main goal of this analysis is to find distant γ-ray blazar candidates that, being too faint at 22 μm, are not detected by WISE and thus are not selected by our purely IR-based methods. We find 55 UGSs that likely correspond to radio sources with blazar-like IR signatures. An additional 11 UGSs that have blazar-like IR colors have been found within the sample of sources found with deep recent Australia Telescope Compact Array observations.« less

Notes on the nesting of egrets near San Rafael, California

Treesearch

C. John Ralph; Clement L. Ralph

1958-01-01

On June 16, 1957, a trip was made by boat to Little Marin Island, off San Rafael, California, for the purpose of banding in the heronry that covers this small privately-owned island. We also wished to investigate the possibility of Snowy Egrets nesting there. The heron colony was conservatively estimated at 2000 birds, of which approximately 50 per cent were Common...

New CO and HCN sources associated with IRAS carbon stars

NASA Technical Reports Server (NTRS)

NGUYEN-Q-RIEU; Epchtein, N.; TRUONG-BACH; Cohen, M.

1987-01-01

Emission of CO and HCN was detected in 22 out of a sample of 53 IRAS sources classified as unidentified carbon-rich objects. The sample was selected according to the presence of the silicon carbide feature as revealed by low-resolution spectra. The molecular line widths indicate that the CO and HCN emission arises from the circumstellar envelopes of very highly evolved stars undergoing mass loss. The visible stars tend to be deficient in CO as compared with unidentified sources. Most the detected CO and HCN IRAS stars are distinct and thick-shelled objects, but their infrared and CO luminosities are similar to those of IRC + 102156 AFGL and IRC-CO evolved stars. The 12 micron flux seems to be a good indicator of the distance, hence a guide for molecular searches.

Exposure of great egret (Ardea albus) nestlings to mercury through diet in the Everglades ecosystem

USGS Publications Warehouse

Frederick, Peter C; Spalding, Marilyn G.; Sepalveda, Maria S.; Williams, Gary E.; Nico, Leo G.; Robins, Robert H.

1999-01-01

We estimated exposure of great egret (Ardea albus) nestlings to mercury in food in the Florida Everglades, USA, by collecting regurgitated food samples during the 1993 to 1996 breeding seasons and during 1995 measured concentrations of mercury in individual prey items from those samples. Great egret nestlings had a diet composed predominantly of fish (>95% of biomass), though the species composition of fish in the diet fluctuated considerably among years. Great egrets concentrated on the larger fish available in the marsh, especially members of the Centrarchidae. The importance of all nonnative fish fluctuated from 0 to 32% of the diet by biomass and was dominated by pike killifish (Belonesox belizanus) and cichlids (Cichlidae). Total mercury concentrations in prey fish ranged from 0.04 to 1.40 mg/kg wet weight, and we found a significant relationship between mass of individual fish and mercury concentration. We estimated the concentration of total mercury in the diet as a whole by weighting the mercury concentration in a given fish species by the proportion of that species in the diet. We estimate that total mercury concentrations in the diets ranged among years from 0.37 to 0.47 mg/kg fish (4-year mean = 0.41 mg/kg). We estimated total mercury exposure in great egret nestlings by combining these mercury concentrations with measurements of food intake rate, as measured over the course of the nestling period in both lab and field situations. We estimate that, at the 0.41 mg/kg level, nestlings would ingest 4.32 mg total mercury during an 80-day nestling period. Captive feeding studies reported elsewhere suggest that this level of exposure in the wild could be associated with reduced fledging mass, increased lethargy, decreased appetite, and, possibly, poor health and juvenile survival.

Evidence for Environmental Dissemination of Antibiotic Resistance Mediated by Wild Birds.

PubMed

Wu, Jiao; Huang, Ye; Rao, Dawei; Zhang, Yongkui; Yang, Kun

2018-01-01

The aquatic bird, egret, could carry antibiotic resistance (AR) from a contaminated waterway (Jin River, Chengdu, China) into the surrounding environment (Wangjianglou Park). A systematic study was carried out on the unique environmental dissemination mode of AR mediated by birds. The minimum inhibitory concentrations of various antibiotics against the environmental Escherichia coli isolates were used to evaluate the bacterial AR at the environmental locations where these isolates were recovered, i.e., the Jin River water, the egret feces, the park soil, and the campus soil. The level of AR in the park soil was significantly higher than that in the campus soil that was seldom affected by the egrets, which suggested that the egrets mediated the transportation of AR from the polluted waterway to the park. Genotyping of the resistant E. coli isolates via repetitive-element PCR gave no strong correlation between the genotypes and the AR patterns of the bacteria. So, the transfer of resistant strains should not be the main mode of AR transportation in this process. The results of real-time PCR revealed that the abundance of antibiotic resistance genes (ARGs) and mobile genetic element (MGE) sequences (transposase and integrase genes) declined along the putative transportation route. The transportation of ARGs could be due to their linkage with MGE sequences, and horizontal gene transfer should have contributed to the process. The movable colistin-resistance gene mcr-1 was detected among the colistin-resistant E. coli strains isolated from the river water and the egret feces, which indicated the possibility of the environmental dissemination of this gene. Birds, especially the migratory birds, for the role they played on the dissemination of environmental AR, should be considered when studying the ecology of AR.

Chandra and Swift Observations of Unidentified Fermi-LAT Objects

NASA Astrophysics Data System (ADS)

Donato, Davide; Cheung, T.; Gehrels, N.

2010-03-01

In the last year we targeted some of the unidentified Fermi-LAT objects (UFOs) at high Galactic latitude with Chandra and Swift in order to determine the basic properties (positions, fluxes, hardness ratios) of all X-ray sources within the Fermi-LAT localization circles. These satellites enable us to detect the X-ray conterparts with a flux limit that is at least an order of magnitude lower than achieved in extant RASS data and to further follow-up at other wavelengths, with the ultimate goal to reveal the nature of these enigmatic gamma-ray sources. Here we present the results obtained with 5 Chandra pointings of high Galactic latitude UFOs in the Fermi-LAT 3-months bright source list. The association of detected X-ray sources within the improved 11-months Fermi-LAT localization circles with available optical and radio observations is discussed.

The estimation of background production by cosmic rays in high-energy gamma ray telescopes

NASA Technical Reports Server (NTRS)

Edwards, H. L.; Nolan, P. L.; Lin, Y. C.; Koch, D. G.; Bertsch, D. L.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Kniffen, D. A.; Hughes, E. B.

1991-01-01

A calculational method of estimating instrumental background in high-energy gamma-ray telescopes, using the hadronic Monte Carlo code FLUKA87, is presented. The method is applied to the SAS-2 and EGRET telescope designs and is also used to explore the level of background to be expected for alternative configurations of the proposed GRITS telescope, which adapts the external fuel tank of a Space Shuttle as a gamma-ray telescope with a very large collecting area. The background produced in proton-beam tests of EGRET is much less than the predicted level. This discrepancy appears to be due to the FLUKA87 inability to transport evaporation nucleons. It is predicted that the background in EGRET will be no more than 4-10 percent of the extragalactic diffuse gamma radiation.

A program of correlated observations using the EGRET instrument on GRO and the IMB neutrino detector

NASA Technical Reports Server (NTRS)

Svoboda, Robert C.

1992-01-01

A reliable, real-time supernova monitoring system was devised using the IMB neutrino detector to serve as an 'early-warning' system for EGRET and other instruments on GRO. New methods and software were developed to allow the IMB monitoring computer in Cleveland to: recognize that a trigger burst had occurred; make a judgement on whether the burst was spurrious or an actual supernova; prepare brief summary files and 'quick-look' data so that a final disposition could be made by a trained scientist; and contact the 'watch' scientist via personal beeper in Baton Rouge. This system ran from Dec. 1990 to Apr. 1991, when the neutrino detector failed for unrelated reasons. In addition to the supernova system, high-energy neutrino data was prepared and formatted for comparison with EGRET gamma-ray data.

Making UFOs make sense: Ufology, science, and the history of their mutual mistrust.

PubMed

Eghigian, Greg

2017-07-01

Reports of unidentified flying objects and alien encounters have sparked amateur research (ufology), government investigations, and popular interest in the subject. Historically, however, scientists have generally greeted the topic with skepticism, most often dismissing ufology as pseudoscience and believers in unidentified flying objects and aliens as irrational or abnormal. Believers, in turn, have expressed doubts about the accuracy of academic science. This study examines the historical sources of the mutual mistrust between ufologists and scientists. It demonstrates that any science doubt surrounding unidentified flying objects and aliens was not primarily due to the ignorance of ufologists about science, but rather a product of the respective research practices of and relations between ufology, the sciences, and government investigative bodies.

Unidentified point sources in the IRAS minisurvey

NASA Technical Reports Server (NTRS)

Houck, J. R.; Soifer, B. T.; Neugebauer, G.; Beichman, C. A.; Aumann, H. H.; Clegg, P. E.; Gillett, F. C.; Habing, H. J.; Hauser, M. G.; Low, F. J.

1984-01-01

Nine bright, point-like 60 micron sources have been selected from the sample of 8709 sources in the IRAS minisurvey. These sources have no counterparts in a variety of catalogs of nonstellar objects. Four objects have no visible counterparts, while five have faint stellar objects visible in the error ellipse. These sources do not resemble objects previously known to be bright infrared sources.

Timing the Geminga Pulsar with High-Energy Gamma-Rays

NASA Technical Reports Server (NTRS)

Halpern, Jules P.

1997-01-01

This is a continuing program to extend and refine the ephemeris of the Geminga pulsar with annual observations for the remaining lifetime of EGRET. The data show that every revolution of Geminga is accounted for during the EGRET epoch, and that a coherent timing solution linking the phase between EGRET, COS-B, amd SAS-2, observations has now been achieved. The accuracy of the gamma-ray timing is such that the proper motion of the pulsar can now be detected, consistent with the optical determination. The measured braking index over the 24.2 yr baseline is 17 +/- 1. Further observation is required to ascertain whether this very large braking index truly represents the energy loss mechanism, perhaps related to the theory in which Geminga is near its gamma-ray death line, or whether it is a manifestation of timing noise. Statistically significant timing residuals are detected in the EGRET data; they depart from the cubic ephemeris at a level of 23 milliperiods. The residuals appear to have a sinusoidal modulation with a period of about 5.1 yr. This could simply be a manifestation of timing noise, or it could be consistent with a planet of mass 1.7/sin i solar mass orbiting Geminga at a radius of 3.3/sin i AU.

The assessment of source attribution of soil pollution in a typical e-waste recycling town and its surrounding regions using the combined organic and inorganic dataset.

PubMed

Luo, Jie; Qi, Shihua; Xie, Xianming; Gu, X W Sophie; Wang, Jinji

2017-01-01

Guiyu is a well-known electronic waste dismantling and recycling town in south China. Concentrations and distribution of the 21 mineral elements and 16 polycyclic aromatic hydrocarbons (PAHs) collected there were evaluated. Principal component analyses (PCA) applied to the data matrix of PAHs in the soil extracted three major factors explaining 85.7% of the total variability identified as traffic emission, coal combustion, and an unidentified source. By using metallic or metalloid element concentrations as variables, five principal components (PCs) were identified and accounted for 70.4% of the information included in the initial data matrix, which can be denoted as e-waste dismantling-related contamination, two different geological origins, anthropogenic influenced source, and marine aerosols. Combining the 21 metallic and metalloid element datasets with the 16 PAH concentrations can narrow down the coarse source and decrease the unidentified contribution to soil in the present study and therefore effectively assists the source identification process.

Mississippi River Headwaters Reservoirs. Minnesota Master Plan for Public Use Development and Resource Management.

DTIC Science & Technology

1977-12-06

Red Oak Woodchuck• ~~Paper BirchWodhc White Tailed Deer SHRUBS BIRDS Chokecherry Great Blue HeronAlwde Common Egret Dogwood Woodduck HERBS...SHRUBS BIRDS Hazelnut Eagle Chokecherry Hawks Juneberry Great Horned Owl Woodpeckers HERBS Chickadee Hepatica Wren Violet Warblers Solomons Seal Sparrows...Snowshoe Hare N. Red Oak Woodchuck Paper Birch White Tailed Deer SHRUBS BIRDS Chokecherry Great Blue Heron Alder Common Egret Dogwood Woodduck HERBS

Aspects of the breeding biology of the Cattle Egret (Bubulcus ibis) in Montserrat, West Indies, and its impact on nest vegetation

Treesearch

W.J. Arendt; A.I. Arendt

1988-01-01

Aspects of the Cattle Egret's reproductive ecology and habitat use in an insular environment were studied on Montserrat, West Indies. Average size of 290 nests (17.9 cm) was smaller than sizes reported in the literature and was attributed to a paucity of available nesting materials. We measured 330 eggs to determine: egg volume (24,117.04 mm3), fresh egg weight (...

KSC-2009-2848

NASA Image and Video Library

2009-04-20

CAPE CANAVERAL, Fla. –– Snowy egrets gather in water on NASA's Kennedy Space Center in Florida. They are distinguished by their slim black beaks, black legs and yellow feet. These egrets inhabit salt marshes, ponds, rice fields and shallow coastal bays. The center shares a boundary with the Merritt Island Wildlife Nature Refuge, which is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. Photo credit: NASA/Dimitri Gerondidakis

KSC-2009-2849

NASA Image and Video Library

2009-04-20

CAPE CANAVERAL, Fla. –– Snowy egrets gather in water on NASA's Kennedy Space Center in Florida. They are distinguished by their slim black beaks, black legs and yellow feet. These egrets inhabit salt marshes, ponds, rice fields and shallow coastal bays. The center shares a boundary with the Merritt Island Wildlife Nature Refuge, which is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. Photo credit: NASA/Dimitri Gerondidakis

Head bobbing and the body movement of little egrets ( Egretta garzetta) during walking.

PubMed

Fujita, Masaki

2003-01-01

Although previous studies have indicated that head bobbing of birds is an optokinetic movement, head bobbing can also be controlled by some biomechanical constraints when it occurs during walking. In the present study, the head bobbing, center of gravity, and body movements of little egrets (Egretta garzetta) during walking were examined by determination of the position of the center of gravity using carcasses and by motion analysis of video films of wild egrets during walking. The results showed that the hold phase occurs while the center of gravity is over the supporting foot during the single support phase. In addition, the peak speed of neck extension was coincident with the peak speed of the center of gravity. These movements are similar to those of pigeons, and suggest the presence of biomechanical constraints on the pattern of head bobbing and body movements during walking.

POTENTIAL FOR GREAT EGRETS (ARDEA ALBA) TO TRANSMIT A VIRULENT STRAIN OF AEROMONAS HYDROPHILA AMONG CHANNEL CATFISH (ICTALURUS PUNCTATUS) CULTURE PONDS.

PubMed

Jubirt, Madison M; Hanson, Larry A; Hanson-Dorr, Katie C; Ford, Lorelei; Lemmons, Scott; Fioranelli, Paul; Cunningham, Fred L

2015-07-01

Aeromonas hydrophila is a gram-negative, rod-shaped, facultative, anaerobic bacterium that is ubiquitous in freshwater and slightly brackish aquatic environments and infects fish, humans, reptiles, and birds. Recent severe outbreaks of disease in commercial channel catfish (Ictalurus punctatus) aquaculture ponds have been associated with a highly virulent A. hydrophila strain (VAH), which is genetically distinct from less-virulent strains. The epidemiology of this disease has not been determined. Given that A. hydrophila infects birds, we hypothesized that fish-eating birds may serve as a reservoir for VAH and spread the pathogen by flying to uninfected ponds. Great Egrets (Ardea alba) were used in this transmission model because these wading birds frequently prey on farmed catfish. Great Egrets that were fed VAH-infected catfish shed VAH in feces demonstrating their potential to spread VAH.

Fourth Workshop on Science with the New Generation of High Energy Gamma-ray Experiments

NASA Astrophysics Data System (ADS)

Massai, Marco Maria; Omodei, Nicola; Spandre, Gloria

I. Space-based telescope. Integral-4 years in orbit / P. Umbertini, P. Caraveo. The Suzaku mission / K. Yamaoka. The Swift mission: two years of operation / A. Moretti. Gamma-ray astrophysics with AGILE / F.Longo et al., The AGILE collaboration. The GLAST mission / J.E. McEnery -- II. Ground-based telescope. Recent results from CANGAROO / M. Mori for the CANGAROO team. The H.E.S.S. project / C. Masterson for the H.E.S.S. collaboration. The MAGIC experiment / N. Turini for the MAGIC collaboration. VERITAS: status and performance / J. Holder for the VERITAS collaboration -- III. Galactic variable sources. Galactic variable sky with EGRET and GLAST / S. Digel. Galactic variable sources observed with H.E.S.S. / N. Komin for the H.E.S.S collaboration. Gamma ray pulsars in the GLAST era / M. Razzano. Solving the riddle of unidentified high-energy gamma-ray sources / P. Caraveo. Supernovae and gamma-ray burst / M. Della Valle. First cycle of MAGIC galactic observations / J. Cortina for the MAGIC collaboration. Gamma-rays and neutrinos from a SNR in the galactic center / V. Cavasinni, D. Grasso, L. Maccione. Solving GRBs and SGRs puzzles by precessing jets / D. Fargion, O. Lanciano, P. Oliva -- IV. Extragalactic sources. Multiwavelength observations and theories of blazers / G. Tosti. AGN observations with the MAGIC telescope / C. Bigongiari for the MAGIC collaboration. Gamma ray bursts/ L. Amati. X-rays and GeV flares in GRB light curves / A. Galli ... [et al.]. The highest energy emission from gamma ray bursts: MILAGRO's constraints and HAWC's potential / B. Dingus for the MILAGRO and HAWC collaborations. Observation of GRB with the MAGIC telescope / N. Galante, P. Piccioli for the MAGIC collaboration. GRB 060218 and the outliers with respect to the E-E correlation / G. Ghirlanda, G. Ghibellini -- V. Poster session. Study of the performance and calibration of the GLAST-LAT silicon tracker / M. Brigida, N. Giglietto, P. Spinelli. The online monitor for the GLAST calibration unit beam test / L. Baldini, J. Bregeon, C. Sgrò. ARGO-YBJ experiment: the scalar mode technique / I. James. on behalf of ARGO-YBJ collaboration. Analysis of pulsars in LAT data challenge 2: a population point of view / M. Razzano. Search of optimized cuts for gamma-ray pulsar detection with GLAST-LAT instrument / A. Calandro, N. Biglietto, P. Spinelli. Gamma-ray burst physics with GLAST / N. Omodei. The global fit approach to time-resolved spectroscopy GRBs / A. Chernenko.

Space Science

NASA Image and Video Library

1991-01-28

This is the STS-37 Crew portrait. Pictured from left to right are Kenneth D. (Ken) Cameron, pilot; Jay Apt, mission specialist; Steven R. Nagel, commander; and Jerry L. Ross and Linda M. Godwin, mission specialists. Launched aboard the Space Shuttle Atlantis on April 5, 1991 at 9:22:44am (EST), the crew’s major objective was the deployment of the Gamma Ray Observatory (GRO). Included in the observatory were the Burst and Transient Source Experiment (BATSE); the Imaging Compton Telescope (COMPTEL); the Energetic Gamma Ray Experiment Telescope (EGRET); and the Oriented Scintillation Spectrometer Telescope (OSSEE).

Space Shuttle Projects

NASA Image and Video Library

1991-04-05

Launched aboard the Space Shuttle Atlantis on April 5, 1991 at 9:22:44am (EST), the STS-37 mission hurtles toward space. Her crew included Steven R. Nagel, commander; Kenneth D. (Ken) Cameron, pilot; and Jay Apt, Jerry L. Ross, and Linda M. Godwin, all mission specialists. The crew’s major objective was the deployment of the Gamma Ray Observatory (GRO). Included in the observatory were the Burst and Transient Source Experiment (BATSE); the Imaging Compton Telescope (COMPTEL); the Energetic Gamma Ray Experiment Telescope (EGRET); and the Oriented Scintillation Spectrometer Telescope (OSSEE).

Performance of the EGRET astronomical gamma ray telescope

NASA Technical Reports Server (NTRS)

Nolan, P. L.; Bertsch, D. L.; Fichtel, C. E.; Hartman, R. C.; Hofstadter, R.; Hughes, E. B.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Lin, Y. C.

1992-01-01

On April 5, 1991, the Space Shuttle Atlantis carried the Compton Gamma Ray Observatory (CGRO) into orbit, deploying the satellite on April 7. The EGRET instrument was activated on April 15, and the first month of operations was devoted to verification of the instrument performance. Measurements made during that month and in the subsequent sky survey phase have verified that the instrument time resolution, angular resolution, and gamma ray detection efficiency are all within nominal limits.

Organochlorine residues and eggshell thinning in anhingas and waders

USGS Publications Warehouse

Ohlendorf, Harry M.; Klaas, Erwin E.; Kaiser, T. Earl; Southern, William E.

1978-01-01

Residues of organochlorine compounds occur commonly in environmental samples and have been associated with adverse effects in numerous avian species (Cooke 1973; L. F. Stickel 1973; W. H. Stickel 1975; Ohlendorf et al. 1977; H. M. Ohlendorf, R. W. Risebrough, and K. Vermeer, unpublished manuscript). The affected species are usually terminal consumers, generally those feeding on aquatic organisms (primarily fish) or birds. Brown Pelicans (Pelecanus occidentalis), Double-crested Cormorants (Phalacrocorax auritus), and certain herons are among the species that have exhibited shell thinning in some regions (see Ohlendorf et al. 1977 for review). In 1972, we began a study to determine: (1) geographic differences in the occurrence of environmental pollutants in Anhingas (Anhinga anhinga) and waders in the eastern United States; (2) differences in environmental pollutant levels among those species nesting at the same localities; and (3) whether eggshell thickness had changed since the widespread use of organochlorine pesticides began in the mid-1940's. The wader species included in our study were: Great Blue Heron (Ardea herodias), Green Heron (Butorides virescens), Little Blue Heron (Florida caerulea), Cattle Egret (Bubulcus ibis), Reddish Egret (Dichromanassa rufescens), Great Egret (Casmerodius albus), Snowy Egret (Egretta thula), Louisiana Heron (Hydranassa tricolor), Black-crowned Night Heron (Nycticorax nycticorax), Yellow-crowned Night Heron (Nyctanassa violacea), Least Bittern (Ixobrychus exilis), American Bittern (Botaurus lentiginosus), Wood Stork (Mycteria americana), Glossy Ibis (Plegadis falcinellus), White Ibis (Eudocimus albus), and Roseate Spoonbill (Ajaia ajaja).

An Intriguing Convex Break in the EGRET SED of Mrk 421

NASA Technical Reports Server (NTRS)

Nandikotkur, Giridhar; Jahoda, Keith M.; Georganopoulos, M.; Hartman, R. C.; Mukherjee, R.; Thompson, D. J.; Swank, Jean H.

2007-01-01

Based upon analysis of the entire EGRET data from Mrk 421, it is found that the time-averaged spectra are inconsistent with the predictions of current theoretical models that have had success in describing simultaneous X-ray/TeV observations, and suggest additional components in the GeV band, as well as complex time variability. Current theoretical pictures explain the GeV emission as comptonization of the synchrotron photons in the jet, and predict hard spectra that should join smoothly with the TeV emission. Our analysis shows that the situation is more complex. The spectrum ranges from hard to soft during individual epochs, and shows a convext break in the aggregated data. We also present the mission-averaged EGRET spectrum for PKS 2155-304, which shows a similar (but not as pronounced) convex curvature. We discuss a series of possible explanations for the 10(exp 22) - 10(exp 23) HZ declining part of the EGRET nu F(sub nu), spectrum for Mrk 421, and suggest that it is synchrotron emission from the high energy tail of the electron population that produces the X-rays during the highest X-ray states. Such multi-MeV photons are produced by electrons accelerated close to the limit of diffusive shock acceleration. Simultaneous GLAST and X-ray observations of high X-ray states will address the issue of the convex curvature in the future.

Investigation of avian influenza infection in wild birds in Ismailia and Damietta cities, Egypt

PubMed Central

Fadel, Hanaa Mohamed; Afifi, Rabab

2017-01-01

Aim: This study was carried out to monitor avian influenza (AI) infection in wild birds in Egypt. Materials and Methods: A total of 135 wild birds were examined for the presence of H5, H7, and H9 hemagglutination inhibition antibodies. Organs and swab samples of 75 birds were screened by multiplex real-time reverse transcriptase-polymerase chain reaction (RRT-PCR) to detect AI subtypes H5, H7, and H9 matrix genes. Results: The highest seropositive result was recorded in cattle egrets (90.9%) followed by crows (88.6%), semi-captive pigeons (44.8%), and moorhens (39.1%). In cattle egrets, semi-captive pigeons and moorhens, H5 antibodies predominated. In crows, H9 antibodies predominated. Multiple infections with two or three virus subtypes were highest in crows (6/39, 15.4%) followed by cattle egrets (3/30, 10%) and moorhens’ (1/9, 11.1%) positive samples. Multiplex RRT-PCR results revealed two positive samples in cattle egrets and moorhens. Conclusion: The results indicated high seropositive rates against AI virus subtypes H5 and H9 in the examined wild birds. Multiple infections with more than one AI virus (AIV) subtypes were detected in some birds. This requires a collaboration of efforts to monitor AIV infection in wild birds and implement suitable early intervention measures. PMID:28717324

Chandra Studies of Unidentified X-ray Sources in the Galactic Bulge

NASA Astrophysics Data System (ADS)

Mori, Hideyuki

2013-09-01

We propose to study a complete X-ray sample in the luminosity range of > 10^34 erg s^-1 in the Galactic bulge, including 5 unidentified sources detected in the ROSAT All Sky Survey. Our goal is to obtain a clear picture about X-ray populations in the bulge, by utilizing the excellent Chandra position accuracy leading to unique optical identification together with the X-ray spectral properties. This is a new step toward understanding the formation history of the bulge. Furthermore, because the luminosity range we observe corresponds to a ``missing link'' region ever studied for a neutron star or blackhole X-ray binary, our results are also unique to test accretion disk theories at intermediate mass accretion rates.

High-energy sources at low radio frequency: the Murchison Widefield Array view of Fermi blazars

DOE PAGES

Giroletti, M.; Massaro, F.; D’Abrusco, R.; ...

2016-04-01

Low-frequency radio arrays are opening a new window for the study of the sky, both to study new phenomena and to better characterize known source classes. Being flat-spectrum sources, blazars are so far poorly studied at low radio frequencies. In this paper, we characterize the spectral properties of the blazar population at low radio frequency, compare the radio and high-energy properties of the gamma-ray blazar population, and search for radio counterparts of unidentified gamma-ray sources. We cross-correlated the 6100 deg 2 Murchison Widefield Array Commissioning Survey catalogue with the Roma blazar catalogue, the third catalogue of active galactic nuclei detectedmore » by Fermi-LAT, and the unidentified members of the entire third catalogue of gamma-ray sources detected by Fermi-LAT. When available, we also added high-frequency radio data from the Australia Telescope 20 GHz catalogue. We find low-frequency counterparts for 186 out of 517 (36%) blazars, 79 out of 174 (45%) gamma-ray blazars, and 8 out of 73 (11%) gamma-ray blazar candidates. The mean low-frequency (120–180 MHz) blazar spectral index is (α low) = 0.57 ± 0.02: blazar spectra are flatter than the rest of the population of low-frequency sources, but are steeper than at ~GHz frequencies. Low-frequency radio flux density and gamma-ray energy flux display a mildly significant and broadly scattered correlation. Ten unidentified gamma-ray sources have a (probably fortuitous) positional match with low radio frequency sources. Low-frequency radio astronomy provides important information about sources with a flat radio spectrum and high energy. However, the relatively low sensitivity of the present surveys still misses a significant fraction of these objects. Finally, upcoming deeper surveys, such as the GaLactic and Extragalactic All-Sky MWA (GLEAM) survey, will provide further insight into this population.« less

High-energy sources at low radio frequency: the Murchison Widefield Array view of Fermi blazars

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giroletti, M.; Massaro, F.; D’Abrusco, R.

Low-frequency radio arrays are opening a new window for the study of the sky, both to study new phenomena and to better characterize known source classes. Being flat-spectrum sources, blazars are so far poorly studied at low radio frequencies. In this paper, we characterize the spectral properties of the blazar population at low radio frequency, compare the radio and high-energy properties of the gamma-ray blazar population, and search for radio counterparts of unidentified gamma-ray sources. We cross-correlated the 6100 deg 2 Murchison Widefield Array Commissioning Survey catalogue with the Roma blazar catalogue, the third catalogue of active galactic nuclei detectedmore » by Fermi-LAT, and the unidentified members of the entire third catalogue of gamma-ray sources detected by Fermi-LAT. When available, we also added high-frequency radio data from the Australia Telescope 20 GHz catalogue. We find low-frequency counterparts for 186 out of 517 (36%) blazars, 79 out of 174 (45%) gamma-ray blazars, and 8 out of 73 (11%) gamma-ray blazar candidates. The mean low-frequency (120–180 MHz) blazar spectral index is (α low) = 0.57 ± 0.02: blazar spectra are flatter than the rest of the population of low-frequency sources, but are steeper than at ~GHz frequencies. Low-frequency radio flux density and gamma-ray energy flux display a mildly significant and broadly scattered correlation. Ten unidentified gamma-ray sources have a (probably fortuitous) positional match with low radio frequency sources. Low-frequency radio astronomy provides important information about sources with a flat radio spectrum and high energy. However, the relatively low sensitivity of the present surveys still misses a significant fraction of these objects. Finally, upcoming deeper surveys, such as the GaLactic and Extragalactic All-Sky MWA (GLEAM) survey, will provide further insight into this population.« less

Genotype Diversity of H9N2 Viruses Isolated from Wild Birds and Chickens in Hunan Province, China

PubMed Central

Wang, Ba; Liu, Zhihua; Chen, Quanjiao; Gao, Zhimin; Fang, Fang; Chang, Haiyan; Chen, Jianjun; Xu, Bing; Chen, Ze

2014-01-01

Three H9N2 avian influenza viruses were isolated from the Dongting Lake wetland, among which one was from fresh egret feces, the other two were from chicken cloacal swabs in poultry markets. Phylogenetic analyses suggested that eight genes of the egret-derived H9N2 virus might come from Korean-like or American-like lineages. The two poultry-derived H9N2 viruses were reassortants between the CK/BJ/94-like and G1-like viruses. Except the PB1 genes (90.6%), the nucleotide sequence of other internal genes of the two viruses exhibited high homology (>95%). In addition, they also exhibited high homology (96–98.3%) with some genes of the H7N9 virus that caused an epidemic in China in 2013. Nucleotide sequence of the poultry-derived and egret-derived H9N2 viruses shared low homology. Infection studies showed that the egret-derived H9N2 virus was non-pathogenic to both mice and chickens, and the virus was unable to infect chickens even through 8 passages continuously in the lung. On the other hand, the chickens infected by poultry-derived viruses showed obvious clinical symptoms and even died; the infected mice showed no noticeable clinical symptoms and weight loss, but viruses could be detected in their lungs. In conclusion, for the egret-derived H9N2 virus, it would take a long adaptation process to achieve cross-species transmission in poultry and mammals. H9N2 viruses isolated at different times from the same host species in the same geographical region presented different evolutionary status, and virus isolated from different hosts in the same geographical region exhibited genetic diversity. Therefore, it is important to continue the H9N2 virus surveillance for understanding their evolutionary trends so as to provide guidance for disease control and prevention. PMID:24979703

Use of noninvasive ‘bug-eggs’ to enable comparative inferences on genetic mating system with and without parental information: A study in a cattle egret colony

PubMed Central

de Souza, Elaine Dantas; Moralez-Silva, Emmanuel; Valdes, Talita Alvarenga; Cortiço Corrêa Rodrigues, Vera Lúcia

2017-01-01

Colonial waterbirds such as herons, egrets and spoonbills exhibit ecological characteristics that could have promoted the evolution of conspecific brood parasitism and extra-pair copulation. However, an adequate characterization of the genetic mating systems of this avian group has been hindered by the lack of samples of elusive candidate parents which precluded conducting conventional parentage allocation tests. Here, we investigate the genetic mating system of the invasive cattle egret using hematophagous insects contained in fake eggs to collect blood from incubating adults in a wild breeding colony. We tested a protocol with a previously unused Neotropical Triatominae, Panstrongylus megistus, obtained blood samples from males and females in 31 nests built on trees, drew blood from 89 nestlings at those nests, and genotyped all samples at 14 microsatellite loci, including six new species-specific loci. We comparatively addressed the performance of parentage allocation versus kinship classification of nestlings to infer the genetic mating system of cattle egrets. In line with previous behavioral observations, we found evidence in support of a non-monogamous genetic mating system, including extra-pair paternity (EPP) and conspecific brood parasitism (CBP). Parentage allocation tests detected a higher percentage of nests with alternative reproductive tactics (EPP: 61.7%; CBP: 64.5%) than the kinship classification method (EPP: 50.0%; CBP: 43.3%). Overall, these results indicate that rates of alternative reproductive tactics inferred in the absence of parental genetic information could be underestimated and should be interpreted with caution. This study highlights the importance of incorporating samples from candidate parents to adequately determine the genetic mating system of a species. We expand knowledge on the reproductive tactics of colonial waterbirds, contributing novel data on the genetic mating system of the cattle egret, valuable for the design of management strategies for this invasive bird. PMID:28854191

Use of noninvasive 'bug-eggs' to enable comparative inferences on genetic mating system with and without parental information: A study in a cattle egret colony.

PubMed

Miño, Carolina Isabel; de Souza, Elaine Dantas; Moralez-Silva, Emmanuel; Valdes, Talita Alvarenga; Cortiço Corrêa Rodrigues, Vera Lúcia; Del Lama, Sílvia Nassif

2017-01-01

Colonial waterbirds such as herons, egrets and spoonbills exhibit ecological characteristics that could have promoted the evolution of conspecific brood parasitism and extra-pair copulation. However, an adequate characterization of the genetic mating systems of this avian group has been hindered by the lack of samples of elusive candidate parents which precluded conducting conventional parentage allocation tests. Here, we investigate the genetic mating system of the invasive cattle egret using hematophagous insects contained in fake eggs to collect blood from incubating adults in a wild breeding colony. We tested a protocol with a previously unused Neotropical Triatominae, Panstrongylus megistus, obtained blood samples from males and females in 31 nests built on trees, drew blood from 89 nestlings at those nests, and genotyped all samples at 14 microsatellite loci, including six new species-specific loci. We comparatively addressed the performance of parentage allocation versus kinship classification of nestlings to infer the genetic mating system of cattle egrets. In line with previous behavioral observations, we found evidence in support of a non-monogamous genetic mating system, including extra-pair paternity (EPP) and conspecific brood parasitism (CBP). Parentage allocation tests detected a higher percentage of nests with alternative reproductive tactics (EPP: 61.7%; CBP: 64.5%) than the kinship classification method (EPP: 50.0%; CBP: 43.3%). Overall, these results indicate that rates of alternative reproductive tactics inferred in the absence of parental genetic information could be underestimated and should be interpreted with caution. This study highlights the importance of incorporating samples from candidate parents to adequately determine the genetic mating system of a species. We expand knowledge on the reproductive tactics of colonial waterbirds, contributing novel data on the genetic mating system of the cattle egret, valuable for the design of management strategies for this invasive bird.

Wildlife Photography - Birds

NASA Image and Video Library

2017-12-14

A snowy egret is seen at NASA's Kennedy Space Center in Florida. Kennedy shares a boundary with the Merritt Island National Wildlife Refuge. The refuge encompasses 140,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fish, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

Gamma rays from pulsar wind shock acceleration

NASA Technical Reports Server (NTRS)

Harding, Alice K.

1990-01-01

A shock forming in the wind of relativistic electron-positron pairs from a pulsar, as a result of confinement by surrounding material, could convert part of the pulsar spin-down luminosity to high energy particles through first order Fermi acceleration. High energy protons could be produced by this mechanism both in supernova remnants and in binary systems containing pulsars. The pion-decay gamma-rays resulting from interaction of accelerated protons with surrounding target material in such sources might be observable above 70 MeV with EGRET (Energetic Gamma-Ray Experimental Telescope) and above 100 GeV with ground-based detectors. Acceleration of protons and expected gamma-ray fluxes from SN1987A, Cyg X-3 type sources and binary pulsars are discussed.

Flat-Spectrum Radio Sources as Likely Counterparts of Unidentified INTEGRAL Sources (Research Note)

NASA Technical Reports Server (NTRS)

Molina, M.; Landi, R.; Bassani, L.; Malizia, A.; Stephen, J. B.; Bazzano, A.; Bird, A. J.; Gehrels, N.

2012-01-01

Many sources in the fourth INTEGRAL/IBIS catalogue are still unidentified since they lack an optical counterpart. An important tool that can help in identifying and classifying these sources is the cross-correlation with radio catalogues, which are very sensitive and positionally accurate. Moreover, the radio properties of a source, such as the spectrum or morphology, could provide further insight into its nature. In particular, flat-spectrum radio sources at high Galactic latitudes are likely to be AGN, possibly associated to a blazar or to the compact core of a radio galaxy. Here we present a small sample of 6 sources extracted from the fourth INTEGRAL/IBIS catalogue that are still unidentified or unclassified, but which are very likely associated with a bright, flat-spectrum radio object. To confirm the association and to study the source X-ray spectral parameters, we performed X-ray follow-up observations with Swift/XRT of all objects. We report in this note the overall results obtained from this search and discuss the nature of each individual INTEGRAL source. We find that 5 of the 6 radio associations are also detected in X-rays; furthermore, in 3 cases they are the only counterpart found. More specifically, IGR J06073-0024 is a flat-spectrum radio quasar at z = 1.08, IGR J14488-4008 is a newly discovered radio galaxy, while IGR J18129-0649 is an AGN of a still unknown type. The nature of two sources (IGR J07225-3810 and IGR J19386-4653) is less well defined, since in both cases we find another X-ray source in the INTEGRAL error circle; nevertheless, the flat-spectrum radio source, likely to be a radio loud AGN, remains a viable and, in fact, a more convincing association in both cases. Only for the last object (IGR J11544-7618) could we not find any convincing counterpart since the radio association is not an X-ray emitter, while the only X-ray source seen in the field is a G star and therefore unlikely to produce the persistent emission seen by INTEGRAL.

Relativistic particle transport in hot accretion disks

NASA Technical Reports Server (NTRS)

Becker, Peter A.; Kafatos, Menas; Maisack, Michael

1994-01-01

Accretion disks around rapidly rotating black holes provide one of the few plausible models for the production of intense radiation in Acitve Galactic Nuclei (AGNs) above energies of several hundred MeV. The rapid rotation of the hole increases the binding energy per nucleon in the last stable orbit relative to the Schwarzschild case, and naturally leads to ion temperatures in the range 10(exp 12) - 10(exp 13) K for sub-Eddington accretion rates. The protons in the hot inner region of a steady, two-temperature disk form a reservoir of energy that is sufficient to power the observed Energetic Gamma Ray Experiment Telescope (EGRET) outbursts if the black hole mass is 10(exp 10) solar mass. Moreover, the accretion timescale for the inner region is comparable to the observed transient timescale of approximately 1 week. Hence EGRET outbursts may be driven by instabilities in hot, two-temperature disks around supermassive black holes. In this paper we discuss turbulent (stochastic) acceleration in hot disks as a possible source of GeV particles and radiation. We constrain the model by assuming the turbulence is powered by a collective instability that drains energy from the hot protons. We also provide some ideas concerning new, high-energy Penrose processes that produce GeV emission be directly tapping the rotational energy of Kerr black holes.

Mercury and drought along the Lower Carson River, Nevada: III. effects on blood and organ biochemistry and histopathology of snowy egrets and black-crowned night-herons on Lahontan Reservoir, 2002-2006

USGS Publications Warehouse

Hoffman, David J.; Henny, Charles J.; Hill, Elwood F.; Grove, Robert A.; Kaiser, James L.; Stebbins, Katherine R.

2009-01-01

A 10-year study (1997-2006) was conducted to evaluate reproduction and health of aquatic birds in the Carson River Basin of northwestern Nevada (on the U.S. Environmental Protection Agency Natural Priorities List) due to high mercury (Hg) concentrations from past mining activities. This part of the study evaluated physiological associations with blood Hg in young snowy egrets (Egretta thula) and black-crowned night-herons (Nycticorax nycticorax), and organ biochemistry and histopathological effects in snowy egrets on Lahontan Reservoir (LR) from the period 2002-2006. LR snowy egret geometric mean total Hg concentrations (μg/g ww) ranged from 1.5 to 4.8 for blood, 2.4 to 3.1 liver, 1.8 to 2.5 kidneys, 1.7 to 2.4 brain, and 20.5 to 36.4 feathers over these years. For night-herons, mean Hg for blood ranged from 1.6 to 7.4. Significant positive correlations were found between total Hg in blood and five plasma enzyme activities of snowy egrets suggesting hepatic stress. Histopathological findings revealed vacuolar changes in hepatocytes in LR snowy egrets as well as correlation of increased liver inflammation with increasing blood and tissue Hg. Hepatic oxidative effects were manifested by decreased hepatic total thiol concentration and glutathione reductase activity and elevated hepatic thiobarbituric acid-reactive substances (TBARS), a measure of lipid peroxidation. However, other hepatic changes indicated compensatory mechanisms in response to oxidative stress, including decreased oxidized glutathione (GSSG) concentration and decreased ratio of GSSG to reduced glutathione. In young black-crowned night-herons, fewer correlations were apparent. In both species, positive correlations between blood total Hg and plasma uric acid and inorganic phosphorus were suggestive of renal stress, which was supported by histopathological findings. Both oxidative effects and adaptive responses to oxidative stress were apparent in kidneys and brain. Vacuolar change and inflammation in peripheral nerves were found to correlate with blood and tissue Hg. Hg-associated effects related to the immune system included alterations in specific white blood cells and lymphoid depletion in the bursa that were correlated with blood and tissue Hg. When the number of plasma variables that differed between young snowy egrets from the LR site and the reference site were compared between wet and drought years, over twice as many variables were affected during drought years. This resulted in many more variables correlating with blood total Hg during dry than during wet years, suggesting the combination of drought and Hg was more stressful than Hg alone. Drought may have exacerbated Hg-related effects as reported previously for overall productivity. This relationship was not evident in black-crowned night-herons, although data were more limited.

Spatio-temporal variability of ichthyophagous bird assemblage around western Mediterranean open-sea cage fish farms.

PubMed

Aguado-Giménez, Felipe; Eguía-Martínez, Sergio; Cerezo-Valverde, Jesús; García-García, Benjamín

2018-06-14

Ichthyophagous birds aggregate at cage fish farms attracted by caged and associated wild fish. Spatio-temporal variability of such birds was studied for a year through seasonal visual counts at eight farms in the western Mediterranean. Correlation with farm and location descriptors was assessed. Considerable spatio-temporal variability in fish-eating bird density and assemblage structure was observed among farms and seasons. Bird density increased from autumn to winter, with the great cormorant being the most abundant species, also accounting largely for differences among farms. Grey heron and little egret were also numerous at certain farms during the coldest seasons. Cattle egret was only observed at one farm. No shags were observed during winter. During spring and summer, bird density decreased markedly and only shags and little egrets were observed at only a few farms. Season and distance from farms to bird breeding/wintering grounds helped to explain some of the spatio-temporal variability. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of mercury on health and first-year survival of free-ranging great egrets (Ardea albus) from southern Florida.

PubMed

Sepúlveda, M S; Williams, G E; Frederick, P C; Spalding, M G

1999-10-01

The objectives of this study were to determine whether elevated mercury (Hg) concentrations have a negative impact on the health and survival of nestling and juvenile free-ranging great egrets (Ardea albus) from southern Florida. During 1994, when health and survival was monitored in a cohort of young birds with naturally variable concentrations of Hg, packed cell volume was positively correlated with blood Hg concentrations, and high Hg concentration in blood was not related to the probability of surviving during the first 10.5 months of life. During 1995, 70 first-hatched great egret chicks were included in a Hg field-dosing experiment to compare the effects of elevated Hg on health and survival. Birds were dosed while in the nest orally every 2.5 days for 15 days with 0.5 mg of methyl mercury chloride (MeHgCl) for an estimated intake of 1.54 mg MeHgCl/kg food intake. These birds were compared with controls, which received an estimated 0.41 mg MeHgCl/kg food. No differences were observed in health parameters or in the probability of surviving during the first 8 months of age between egrets that were dosed with Hg and those that were not. A likely explanation for the lack of any effects on health and survival between both groups could be that chicks at this age were eliminating most of the dietary Hg through the production of new feathers.

Feather mercury concentrations and physiological condition of great egret and white ibis nestlings in the Florida Everglades

USGS Publications Warehouse

Herring, G.; Gawlik, D.E.; Rumbold, D.G.

2009-01-01

Mercury contamination in the Florida Everglades has reportedly played a role in the recent decline of wading birds, although no studies have identified a mechanism leading to population-level effects. We assessed feather mercury levels in great egret (Ardea alba; n = 91) and white ibis (Eudocimus albus; n = 46) nestlings at breeding colonies in the Florida Everglades during a year (2006) with excellent breeding conditions (characterized by hydrology leading to concentrated prey) and a year with below average breeding conditions (2007). We also assessed the physiological condition of those nestlings based on levels of plasma and fecal corticosterone metabolites, and stress proteins 60 and 70. Mercury levels were higher in both species during the good breeding condition year (great egret = 6.25????g/g ?? 0.81 SE, white ibis = 1.47????g/g ?? 0.41 SE) and lower in the below average breeding year (great egret = 1.60????g/g ?? 0.11 SE, white ibis = 0.20????g/g ?? 0.03 SE). Nestlings were in better physiological condition in 2006, the year with higher feather mercury levels. These results support the hypothesis that nestlings are protected from the harmful effects of mercury through deposition of mercury in growing feathers. We found evidence to suggest shifts in diets of the two species, as a function of prey availability, thus altering their exposure profiles. However, we found no evidence to suggest they respond differently to mercury exposure. ?? 2008 Elsevier B.V. All rights reserved.

Mercury contamination in free-ranging great egret nestlings (Ardea albus) from southern Florida, USA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sepulveda, M.S.; Frederick, P.C.; Spalding, M.G.

1999-05-01

Between March and June of 1994 and 1995, mercury (Hg) concentrations were determined from 393 blood and 164 growing scapular feathers from 252 great egret nestlings (Ardea albus). Nestlings came from eight colonies located in Water Conservation Area 3 in the Everglades region in southern Florida. The ages of these birds ranged from 1 to 44 d (bill length 1.1 to 10.2 cm). Mercury concentrations in blood and feathers of first-hatched great egret nestlings sampled during 1994 averaged 1.2 {micro}g/g (range = 0.07--3.9) wet weight and 16 {micro}g/g (4.5--40) dry weight, respectively. During 1995, first-hatched chicks had blood and feathermore » Hg concentrations that averaged 0.8 {micro}g/g (0.2--1.7) and 9.7 {micro}g/g (2.3--26), respectively. In both years, Hg concentrations in blood and feathers were significantly correlated, and a significant correlation also was found between Hg in blood and age of the chicks. Blood and feather Hg concentrations differed significantly between years, with higher concentrations during 1994. Birds from JW1 and L67 colonies had the highest concentrations of Hg in blood and feathers. Mercury concentrations did not differ between chicks of different hatch order Mercury in feathers of great egret nestlings from southern Florida are approximately six times higher than when compared to feather Hg concentrations of nestlings wading birds sampled elsewhere.« less

Unidentified Gamma-Ray Sources: Hunting Gamma-Ray Blazars

DOE Office of Scientific and Technical Information (OSTI.GOV)

Massaro, F.; D'Abrusco, R.; Tosti, G.

2012-04-02

One of the main scientific objectives of the ongoing Fermi mission is unveiling the nature of the unidentified {gamma}-ray sources (UGSs). Despite the large improvements of Fermi in the localization of {gamma}-ray sources with respect to the past {gamma}-ray missions, about one third of the Fermi-detected objects are still not associated to low energy counterparts. Recently, using the Wide-field Infrared Survey Explorer (WISE) survey, we discovered that blazars, the rarest class of Active Galactic Nuclei and the largest population of {gamma}-ray sources, can be recognized and separated from other extragalactic sources on the basis of their infrared (IR) colors. Basedmore » on this result, we designed an association method for the {gamma}-ray sources to recognize if there is a blazar candidate within the positional uncertainty region of a generic {gamma}-ray source. With this new IR diagnostic tool, we searched for {gamma}-ray blazar candidates associated to the UGS sample of the second Fermi {gamma}-ray catalog (2FGL). We found that our method associates at least one {gamma}-ray blazar candidate as a counterpart each of 156 out of 313 UGSs analyzed. These new low-energy candidates have the same IR properties as the blazars associated to {gamma}-ray sources in the 2FGL catalog.« less

UNIDENTIFIED {gamma}-RAY SOURCES: HUNTING {gamma}-RAY BLAZARS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Massaro, F.; Ajello, M.; D'Abrusco, R.

2012-06-10

One of the main scientific objectives of the ongoing Fermi mission is unveiling the nature of unidentified {gamma}-ray sources (UGSs). Despite the major improvements of Fermi in the localization of {gamma}-ray sources with respect to the past {gamma}-ray missions, about one-third of the Fermi-detected objects are still not associated with low-energy counterparts. Recently, using the Wide-field Infrared Survey Explorer survey, we discovered that blazars, the rarest class of active galactic nuclei and the largest population of {gamma}-ray sources, can be recognized and separated from other extragalactic sources on the basis of their infrared (IR) colors. Based on this result, wemore » designed an association method for the {gamma}-ray sources to recognize if there is a blazar candidate within the positional uncertainty region of a generic {gamma}-ray source. With this new IR diagnostic tool, we searched for {gamma}-ray blazar candidates associated with the UGS sample of the second Fermi {gamma}-ray LAT catalog (2FGL). We found that our method associates at least one {gamma}-ray blazar candidate as a counterpart to each of 156 out of 313 UGSs analyzed. These new low-energy candidates have the same IR properties as the blazars associated with {gamma}-ray sources in the 2FGL catalog.« less

Space Detectors for Gamma Rays (100 MeV-100 GeV): from Egret to Fermi LAT

NASA Technical Reports Server (NTRS)

Thompson, David J.

2015-01-01

The design of spaceborne high-energy (E is greater than 100 MeV) gamma-ray detectors depends on two principal factors: (1) the basic physics of detecting and measuring the properties of the gamma rays; and (2) the constraints of operating such a detector in space for an extended period. Improvements in technology have enabled major advances in detector performance, as illustrated by two successful instruments, EGRET on the Compton Gamma Ray Observatory and LAT on the Fermi Gamma-ray Space Telescope.

Population Characteristics and the Nature of Egg Shells of two Phthirapteran Species Parasitizing Indian Cattle Egrets

PubMed Central

Ahmad, Aftab; Khan, Vikram; Badola, Smita; Arya, Gaurav; Bansal, Nayanci; Saxena, A. K.

2010-01-01

The prevalence, intensities of infestation, range of infestation and population composition of two phthirapteran species, Ardeicola expallidus Blagoveshtchensky (Phthiraptera: Philopteridae) and Ciconiphilus decimfasciatus Boisduval and Lacordaire (Menoponidae) on seventy cattle egrets were recorded during August 2004 to March 2005, in India. The frequency distribution patterns of both the species were skewed but did not correspond to the negative binomial model. The oviposition sites, egg laying patterns and the nature of the eggs of the two species were markedly different. PMID:21067416

KSC-02pd0436

NASA Image and Video Library

2002-03-29

KENNEDY SPACE CENTER, FLA. -- An immature -- therefore white -- Little Blue Heron (center, with black bill) joins Roseate Spoonbills and a pair of Great Egrets in a lake near Kennedy Space Center. The heron ranges along the east coast of the United States, from New York to Texas, inland to Oklahoma. It winters from South Carolina to South America. For habitat the Little Blue Heron prefers freshwater swamps and lagoons in the South, coastal thickets on islands in the North. The species is often observed in large mixed concentrations of herons and egrets

Mercury and drought along the lower Carson River, Nevada: I. Snowy egret and black-crowned night-heron annual exposure to mercury, 1997-2006

USGS Publications Warehouse

Henny, C.J.; Hill, E.F.; Grove, R.A.; Kaiser, J.L.

2007-01-01

The dynamic nature of the annual volume of water discharged down the Carson River over a 10-year period, which included a century flood and drought, was examined in order to gain a better understanding of mercury movement, biological availability, and exposure to waterbirds nesting at Lahontan Reservoir. Total annual water discharge directly influenced total mercury (THg) in unfiltered water above the reservoir and downstream of a mining area, whereas methyl mercury (MeHg) at the same site was negatively related to annual discharge. Annual water storage at Lahontan Reservoir in the spring and early summer, as expected, was directly related to annual Carson River discharge. In contrast to the findings from above the reservoir, annual MeHg concentrations in water sampled below the reservoir were positively correlated with the total discharge and the amount of water stored in the reservoir on 1 July; that is, the reservoir is an important location for mercury methylation, which agrees with earlier findings. However, unfiltered water MeHg concentrations were about 10-fold higher above than below the reservoir, which indicated that much MeHg that entered as well as that produced in the reservoir settled out in the reservoir. Avian exposure to mercury at Lahontan Reservoir was evaluated in both eggs and blood of young snowy egrets (Egretta thula) and black-crowned night-herons (Nycticorax nycticorax). Annual MeHg concentrations in unfiltered water below the reservoir, during the time period (Julian Days 90-190) when birds were present, correlated significantly with mercury concentrations in night-heron blood (r 2= 0.461, p = 0.027), snowy egret blood (r 2= 0.474, p = 0.024), and night-heron eggs (r 2 = 0.447, p = 0.029), but not snowy egret eggs. A possible reason for lack of an MeHg water correlation with snowy egret eggs is discussed and relates to potential exposure differences associated with the food habits of both species. THg concentrations in water collected below the reservoir were not related to egg or blood mercury concentrations for either species. ?? 2007 Springer Science+Business Media, LLC.

Infrared emission spectra of candidate interstellar aromatic molecules

NASA Technical Reports Server (NTRS)

Schlemmer, S.; Balucani, N.; Wagner, D. R.; Steiner, B.; Saykally, R. J.

1996-01-01

Interstellar dust is responsible, through surface reactions, for the creation of molecular hydrogen, the main component of the interstellar clouds in which new stars form. Intermediate between small, gas-phase molecules and dust are the polycyclic aromatic hydrocarbons (PAHs). Such molecules could account for 2-30% of the carbon in the Galaxy, and may provide nucleation sites for the formation of carbonaceous dust. Although PAHs have been proposed as the sources of the unidentified infrared emission bands that are observed in the spectra of a variety of interstellar sources, the emission characteristics of such molecules are still poorly understood. Here we report laboratory emission spectra of several representative PAHs, obtained in conditions approximating those of the interstellar medium, and measured over the entire spectral region spanned by the unidentified infrared bands. We find that neutral PAHs of small and moderate size can at best make only a minor contribution to these emission bands. Cations of these molecules, as well as much larger PAHs and their cations, remain viable candidates for the sources of these bands.

Five New Millisecond Pulsars from a Radio Survey of 14 Unidentified Fermi-LAT Gamma-Ray Sources

NASA Technical Reports Server (NTRS)

Kerr, M.; Camilo, F.; Johnson, T. J.; Ferrara, E. C.; Guillemot, L.; Harding, A. K.; Hessels, J.; Johnson, S.; Keith, M.; Kramer, M.;

Dynamic habitat selection by two wading bird species with divergent foraging strategies in a seasonally fluctuating wetland

USGS Publications Warehouse

Beerens, James M.; Gawlik, Dale E.; Herring, Garth; Cook, Mark I.

2011-01-01

Seasonal and annual variation in food availability during the breeding season plays an influential role in the population dynamics of many avian species. In highly dynamic ecosystems like wetlands, finding and exploiting food resources requires a flexible behavioral response that may produce different population trends that vary with a species' foraging strategy. We quantified dynamic foraging-habitat selection by breeding and radiotagged White Ibises (Eudocimus albus) and Great Egrets (Ardea alba) in the Florida Everglades, where fluctuation in food resources is pronounced because of seasonal drying and flooding. The White Ibis is a tactile “searcher” species in population decline that specializes on highly concentrated prey, whereas the Great Egret, in a growing population, is a visual “exploiter” species that requires lower prey concentrations. In a year with high food availability, resource-selection functions for both species included variables that changed over multiannual time scales and were associated with increased prey production. In a year with low food availability, resource-selection functions included short-term variables that concentrated prey (e.g., water recession rates and reversals in drying pattern), which suggests an adaptive response to poor foraging conditions. In both years, the White Ibis was more restricted in its use of habitats than the Great Egret. Real-time species—habitat suitability models were developed to monitor and assess the daily availability and quality of spatially explicit habitat resources for both species. The models, evaluated through hindcasting using independent observations, demonstrated that habitat use of the more specialized White Ibis was more accurately predicted than that of the more generalist Great Egret.

On how Cattle Egret (Bubulcus ibis) spread to the Americas: meteorological tools to assess probable colonization trajectories.

PubMed

Massa, Carolina; Doyle, Moira; Fortunato, Roberta Callicó

2014-11-01

The Cattle Egret (Bubulcus ibis) is native to the old world. Before 1877 no Cattle Egrets had been sighted in the Americas. There are no written records of this species being transported to or escaping from captivity in South America and there is enough evidence to suggest that individuals are capable of making the crossing from Africa to the Americas unaided. Since long-distance movements of species are partly dependent on meteorological events we analyze the possibility of B. ibis crossing the Atlantic Ocean aided only by wind conditions evaluating existing theories and shedding light on their feasibility through the analysis of weather patterns and atmospheric circulation. Zonal and meridional wind components taken from the Twentieth Century Reanalysis Project were used to calculate trajectories between different points along the West African coast and South America between 1871 and 1920 in two seasons (March-April and September-October). From a total of 192,864 trajectories analyzed, 1,695 with origin in the west coast of Africa reached the NE coast of South America or the Caribbean islands in less than a week (successful trajectories). The probability of these successful trajectories originating in Central Africa was above 0.65 for the majority of the destinations analyzed. Particularly, in Guyana and Suriname where B. ibis was first sighted, the probability of the origin being Central Africa was 0.84, most of them occurring during March. Several weather events favored not only the colonization of the Cattle Egret but also its establishment and spread all throughout the Americas.

Galactic Diffuse Gamma Ray Emission Is Greater than 10 Gev

NASA Technical Reports Server (NTRS)

Hunter, Stanley D.; White, Nicholas E. (Technical Monitor)

2000-01-01

AGILE and Gamma-ray Large Area Telescope (GLAST) are the next high-energy gamma-ray telescopes to be flown in space. These instruments will have angular resolution about 5 times better than Energetic Gamma-Ray Experiment Telescope (EGRET) above 10 GeV and much larger field of view. The on-axis effective area of AGILE will be about half that of EGRET, whereas GLAST will have about 6 times greater effective area than EGRET. The capabilities of ground based very high-energy telescopes are also improving, e.g. Whipple, and new telescopes, e.g. Solar Tower Atmospheric Cerenkov Effect Experiment (STACEE), Cerenkov Low Energy Sampling and Timing Experiment (CELESTE), and Mars Advanced Greenhouse Integrated Complex (MAGIC) are expected to have low-energy thresholds and sensitivities that will overlap the GLAST sensitivity above approximately 10 GeV. In anticipation of the results from these new telescopes, our current understanding of the galactic diffuse gamma-ray emission, including the matter and cosmic ray distributions is reviewed. The outstanding questions are discussed and the potential of future observations with these new instruments to resolve these questions is examined.

New Theoretical Estimates of the Contribution of Unresolved Star-Forming Galaxies to the Extragalactic Gamma-Ray Background (EGB) as Measured by EGRET and the Fermi-LAT

NASA Technical Reports Server (NTRS)

Venters, Tonia M.

2011-01-01

We present new theoretical estimates of the contribution of unresolved star-forming galaxies to the extragalactic gamma-ray background (EGB) as measured by EGRET and the Fermi-LAT. We employ several methods for determining the star-forming galaxy contribution the the EGB, including a method positing a correlation between the gamma-ray luminosity of a galaxy and its rate of star formation as calculated from the total infrared luminosity, and a method that makes use of a model of the evolution of the galaxy gas mass with cosmic time. We find that depending on the model, unresolved star-forming galaxies could contribute significantly to the EGB as measured by the Fermi-LAT at energies between approx. 300 MeV and approx. few GeV. However, the overall spectrum of unresolved star-forming galaxies can explain neither the EGRET EGB spectrum at energies between 50 and 200 MeV nor the Fermi-LAT EGB spectrum at energies above approx. few GeV.

Organochlorines and selenium in California night-heron and egret eggs

USGS Publications Warehouse

Ohlendorf, Harry M.; Marois, Katherine C.

1990-01-01

Exceptionally high concentrations of DDE were found in black-crowned night-heron (Nycticorax nycticorax) (geometric mean 8.62 μg g−1 wet wt.) and great egret (Casmerodius albus) (24.0 μg g−1) eggs collected from the Imperial Valley (Salton Sea), California in 1985. DDE concentrations in 14 of the 87 (16%) randomly selected night-heron eggs from six colonies (two in San Francisco Bay, three in the San Joaquin Valley, and one at Salton Sea) were higher than those associated with reduced reproductive success of night-herons (8 μg g−1). In addition, mean shell thickness of night-heron eggs collected from the San Joaquin Valley and from San Francisco Bay during 1982–1984 was significantly less than pre-DDT thickness and was negatively correlated (r=−0.50, n=75, P<0.0001) with DDE concentration. Mean selenium concentration in night-heron eggs from Salton Sea (1.10 μg g−1) was significantly higher than in eggs from three locations in the San Joaquin Valley, and in egret eggs from Salton Sea.

Search for Pulsations from a Nearby Millisecond Pulsar and Wasilewski 49: Mirror for a Hidden Seyfert 1 Nucleus

NASA Technical Reports Server (NTRS)

Halpern, Jules P.

1999-01-01

Five studies are reported in this final report. The recently discovered 5.3 ms pulsar J1012+5307 at a distance of 520 pc is in an area of the sky which is particularly deficient in absorbing gas. The column density along the line of sight is less than 7.5 x 10(exp 19) CM(exp -2) which facilitates soft X-ray observations. Halpern reported a possible ROSAT Position Sensitive Proportional Counter (PSPC) detection of the pulsar in a serendipitous, off-axis observation. We have now confirmed the X-ray emission of PSR J1012+,5307 in a 23 ksec observation with the ROSAT High Resolution Imager (HRI). A point source is detected within 3" of the radio position. Its count rate of 1.6 +/- 0.3 x 10(exp -3) s(exp -1) corresponds to an unabsorbed 0. 1-2.4 keV flux of 6.4 x 10(exp -14) ergs cm(exp -2) s(exp -1), similar to that reported previously. This counts-to-flux conversion is valid for N(sub H) = 5 x 10(exp 19) cm(exp -2), and either a power-law spectrum of photon index 2.5 or a blackbody of kT = 0.1 keV. The implied X-ray luminosity of 2.0 x 10(exp 30) ergs s(exp -1) is 5 X 10(exp -4) of the pulsar's spin-down power dot-E, and similar to that of the nearest millisecond pulsar J0437-4715, which is nearly a twin of J1012+5307 in P dot-E. We subjected the 37 photons (and 13 background counts) within the source region to a pulsar search, but no evidence for pulsation was found. The pulsar apparently emits over a large fraction of its rotation cycle, and the absence of sharp modulation can be taken as evidence for surface thermal emission, as is favored for PSR J0437-4715, rather than magnetospheric X-ray emission which is apparent in the sharp pulses of the much more energetic millisecond pulsar B1821-24. A further test of this interpretation will be made with a longer ROSAT observation, which will increase the number of photons collected by a factor of 5, and permit a more sensitive examination of the light curve for modulation due to emission from heated polar caps. If found, such modulation will be further evidence that surface reheating by the impact of particles accelerated along open fiel;d lines operates in these approximately 10(exp -9) year old pulsars. In a second study, a new AM Her star serendipitously in a 25 day observation was detected with the EUVE satellite. A coherent period of 85.82 min is present in the EUVE Deep Survey imager light curve of this source. A spectroscopic optical identification is made with a 19th magnitude blue star that has H and He emission lines, and broad cyclotron humps typical of a magnetic cataclysmic variable. A lower limit to the polar magnetic field of 50 MG is estimated from the spacing of the cyclotron harmonics. EUVE J0425.6-5714 is also detected in archival ROSAT HRI observations spanning two months, and its stable and highly structured light curve permits us to fit a coherent ephemeris linking the ROSAT and EUVE data over a 1.3 yr gap. The derived period is 85.82107 +/- 0.00020 min, and the ephemeris should be accurate to 0.1 cycles until the year 2005. A narrow but partial X-ray eclipse suggests that this object belongs to the group of AM Her stars whose viewing geometry is such that the accretion stream periodically occults the soft X-ray emitting accretion spot on the surface of the white dwarf. A non-detection of hard X-rays from ASCA observations that are contemporaneous with the ROSAT HRI shows that the soft X-rays must dominate by at least an order of magnitude, which is consistent with a known trend among AM Her stars with large magnetic field. This object should not be confused with the Seyfert galaxy IH 0419-577 (= LB 1727), another X-ray/EUV source which lies only 3'95 away, and was the principal target of these monitoring observations. In a third report; the identity of the persistent high-energy (> 100 MeV) gamma-ray sources in the Galaxy, still largely a mystery is investigated. The second installment of the EGRET (2EG) lists a total of 128 sources, of which 51 are likely or possibly identified with AGNs, five with rotation-powered pulsars, and one is the LMC. There are 71 unidentified sources, of which 33, or almost half, lie in the narrow band of absolute value of b < 10 degrees along the Galactic plane. This excess of low-latitude sources must, therefore, constitute a Galactic population that is either similar to the already identified gamma-ray pulsars, or an entirely new class of gamma-ray emitters associated with the disk population. We are continuing our program, begun in A06, that is aimed at intermediate-latitude sources, arguing that X-ray detection of them is the most plausible method of identifying the Galactic population. The sources at high latitude must statistically be mostly AGNS, and are more straightforwardly identified through radio and optical means. For the fourth report, identification of the EGRET Source the identity of the persistent, high-energy gamma-ray sources in the Galactic plane is a mystery. The most likely scenario is a population of middle-aged pulsars, many of which could be radio quiet like Geminga. We have an ongoing program of ROSAT, VLA, and optical observations of selected EGRET error circles at intermediate Galactic latitude. For one of these fields, at (l, b) = (106 degrees, +3), our complete census of X-ray and radio sources, reveals a remarkable association between a radio shell with unique properties, and a complete census of X-ray and radio sources reveals a remarkable association between a radio shell with unique properties, and a compact X-ray source. Further observations are needed to determine whether or not this source has a hard X-ray spectrum like that of other gamma ray pulsars and, ideally, to find its pulsations. A fifth report reviews, Wasilewski 49, an interacting pair of Seyfert galaxies at z = 0.063, one of which contains a hidden Seyfert I nucleus as evidenced by broad wings on its Balmer lines.

Chandra follow up analysis on HESS J1841-055

NASA Astrophysics Data System (ADS)

Wilbert, Sven

2012-07-01

State of the art Imaging Atmospheric Cherenkow Telescopes (IACTs) like the Very Energetic Radiation Imaging Telescope Array System (VERITAS) and the High Energy Stereoscopic System (H.E.S.S) made surveys of the sky in order to discover new sources. The first and most famous is the H.E.S.S survey of the inner Galactic plane. So far more than 50 Galactic TeV Gamma-ray sources have been detected, a large number of which remain unidentified. HESS J1841-055 is one of the largest and most complex among these unidentified sources with an extension of approximately 1°. Follow up observations of the HESS J1841-055 region with Chandra, which is due to its high resolution good suited for searching for X-Ray counterparts and add-on analysis have revealed several X-ray sources spatially coincident with the multiple TeV emission peaks. The search for counterparts brought out the fact that not a single source itself but a bunch of sources of different nature, could be indeed the creators of this complex diffuse emission region; among them the SNR Kes 73, the pulsar within Kes 73, 1E 1841-45 and also the High Mass X-Ray Binary AX 184100.4-0536 and others.

VizieR Online Data Catalog: Jet kinematics of blazars at 43GHz with the VLBA (Jorstad+, 2017)

NASA Astrophysics Data System (ADS)

Jorstad, S. G.; Marscher, A. P.; Morozova, D. A.; Troitsky, I. S.; Agudo, I.; Casadio, C.; Foord, A.; Gomez, J. L.; MacDonald, N. R.; Molina, S. N.; Lahteenmaki, A.; Tammi, J.; Tornikoski, M.

2018-04-01

The VLBA-BU-BLAZAR monitoring program consists of approximately monthly observations with the VLBA at 43GHz of a sample of AGNs detected as γ-ray sources. In this paper, we present the results of observations from 2007 June to 2013 January. The sample consists of 21 FSRQs, 12 BLLacs, and 3 radio galaxies (RGs). It includes the blazars and radio galaxies detected at γ-ray energies by EGRET with average flux density at 43GHz exceeding 0.5Jy, declination north of -30°, and optical magnitude in the R band brighter than 18.5. (5 data files).

Sources and elemental composition of ambient PM(2.5) in three European cities.

PubMed

Vallius, M; Janssen, N A H; Heinrich, J; Hoek, G; Ruuskanen, J; Cyrys, J; Van Grieken, R; de Hartog, J J; Kreyling, W G; Pekkanen, J

2005-01-20

Source apportionment of urban fine particle mass (PM(2.5)) was performed from data collected during 1998-1999 in Amsterdam (The Netherlands), Erfurt (Germany) and Helsinki (Finland), using principal component analysis (PCA) and multiple linear regression. Six source categories of PM(2.5) were identified in Amsterdam. They were traffic-related particles (30% of the average PM(2.5)), secondary particles (34%), crustal material (7%), oil combustion (11%), industrial and incineration processes (9%), and sea salt (2%). The unidentified PM(2.5) fraction was 7% on the average. In Erfurt, four source categories were extracted with some difficulties in interpretation of source profiles. They were combustion emissions related to traffic (32%), secondary PM (32%), crustal material (21%) and industrial processes (8%). In Erfurt, 3% of PM(2.5) remained unidentified. Air pollution data and source apportionment results from the two Central European cities were compared to previously published results from Helsinki, where about 80% of average PM(2.5) was attributed to transboundary air pollution and particles from traffic and other regional combustion sources. Our results indicate that secondary particles and local combustion processes (mainly traffic) were the most important source categories in all cities; their impact on the average PM(2.5) was almost equal in Amsterdam and Erfurt whereas, in Helsinki, secondary particles made up for as much as half of the total average PM(2.5).

Landscape factors and hydrology influence mercury concentrations in wading birds breeding in the Florida Everglades, USA.

PubMed

Herring, Garth; Eagles-Smith, Collin A; Ackerman, Joshua T; Gawlik, Dale E; Beerens, James M

2013-08-01

The hydrology of wetland ecosystems is a key driver of both mercury (Hg) methylation and waterbird foraging ecology, and hence may play a fundamental role in waterbird exposure and risk to Hg contamination. However, few studies have investigated hydrological factors that influence waterbird Hg exposure. We examined how several landscape-level hydrological variables influenced Hg concentrations in great egret and white ibis adults and chicks in the Florida Everglades. The great egret is a visual "exploiter" species that tolerates lower prey densities and is less sensitive to hydrological conditions than is the white ibis, which is a tactile "searcher" species that pursues higher prey densities in shallow water. Mercury concentrations in adult great egrets were most influenced by the spatial region that they occupied in the Everglades (higher in the southern region); whereas the number of days a site was dry during the previous dry season was the most important factor influencing Hg concentrations in adult ibis (Hg concentrations increased with the number of days dry). In contrast, Hg concentrations in egret chicks were most influenced by calendar date (increasing with date), whereas Hg concentrations in ibis chicks were most influenced by chick age, region, and water recession rate (Hg concentrations decreased with age, were higher in the southern regions, and increased with positive water recession rates). Our results indicate that both recent (preceding two weeks) hydrological conditions, and those of the prior year, influence Hg concentrations in wading birds. Further, these results suggest that Hg exposure in wading birds is driven by complex relationships between wading bird behavior and life stage, landscape hydrologic patterns, and biogeochemical processes. Published by Elsevier B.V.

Landscape factors and hydrology influence mercury concentrations in wading birds breeding in the Florida Everglades, USA

USGS Publications Warehouse

Herring, Garth; Eagles-Smith, Collin A.; Ackerman, Joshua T.; Gawlik, Dale E.; Beerens, James M.

2013-01-01

The hydrology of wetland ecosystems is a key driver of both mercury (Hg) methylation and waterbird foraging ecology, and hence may play a fundamental role in waterbird exposure and risk to Hg contamination. However, few studies have investigated hydrological factors that influence waterbird Hg exposure. We examined how several landscape-level hydrological variables influenced Hg concentrations in great egret and white ibis adults and chicks in the Florida Everglades. The great egret is a visual “exploiter” species that tolerates lower prey densities and is less sensitive to hydrological conditions than is the white ibis, which is a tactile “searcher” species that pursues higher prey densities in shallow water. Mercury concentrations in adult great egrets were most influenced by the spatial region that they occupied in the Everglades (higher in the southern region); whereas the number of days a site was dry during the previous dry season was the most important factor influencing Hg concentrations in adult ibis (Hg concentrations increased with the number of days dry). In contrast, Hg concentrations in egret chicks were most influenced by calendar date (increasing with date), whereas Hg concentrations in ibis chicks were most influenced by chick age, region, and water recession rate (Hg concentrations decreased with age, were higher in the southern regions, and increased with positive water recession rates). Our results indicate that both recent (preceding two weeks) hydrological conditions, and those of the prior year, influence Hg concentrations in wading birds. Further, these results suggest that Hg exposure in wading birds is driven by complex relationships between wading bird behavior and life stage, landscape hydrologic patterns, and biogeochemical processes.

Gamma rays from Centaurus A

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gupta, Nayantara, E-mail: nayan@phy.iitb.ac.in

2008-06-15

Centaurus A, the cosmic ray accelerator a few Mpc away from us, is possibly one of the nearest sources of extremely high energy cosmic rays. We investigate whether the gamma ray data currently available from Centaurus A in the GeV-TeV energy band can be explained with only proton-proton interactions. We show that for a single power law proton spectrum, mechanisms of {gamma}-ray production other than proton-proton interactions are needed inside this radio-galaxy to explain the gamma ray flux observed by EGRET, upper limits from HESS/CANGAROO-III and the correlated extremely energetic cosmic ray events observed by the Pierre Auger experiment. Inmore » future, with better {gamma}-ray data, and simultaneous observation with {gamma}-ray and cosmic ray detectors, it will be possible to carry out such studies on different sources in more detail.« less

A TALE OF THREE MYSTERIOUS SPECTRAL FEATURES IN CARBON-RICH EVOLVED STARS: THE 21 μm, 30 μm, AND “UNIDENTIFIED INFRARED” EMISSION FEATURES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mishra, Ajay; Li, Aigen; Jiang, B. W., E-mail: amishra@mail.missouri.edu, E-mail: lia@missouri.edu, E-mail: bjiang@bnu.edu.cn

2015-03-20

The mysterious “21 μm” emission feature seen almost exclusively in the short-lived protoplanetary nebula (PPN) phase of stellar evolution remains unidentified since its discovery two decades ago. This feature is always accompanied by the equally mysterious, unidentified “30 μm” feature and the so-called “unidentified infrared” (UIR) features at 3.3, 6.2, 7.7, 8.6, and 11.3 μm which are generally attributed to polycyclic aromatic hydrocarbon (PAH) molecules. The 30 μm feature is commonly observed in all stages of stellar evolution from the asymptotic giant branch through PPN to the planetary nebula phase. We explore the interrelations among the mysterious 21, 30 μm,more » and UIR features of the 21 μm sources. We derive the fluxes emitted in the observed UIR, 21, and 30 μm features from published Infrared Space Observatory or Spitzer/IRS spectra. We find that none of these spectral features correlate with each other. This argues against a common carrier (e.g., thiourea) for both the 21 μm feature and the 30 μm feature. This also does not support large PAH clusters as a possible carrier for the 21 μm feature.« less

In-Flight Calibration of the Energetic Gamma-Ray Experiment Telescope (EGRET) on the Compton Gamma-Ray Observatory

NASA Technical Reports Server (NTRS)

Esposito, J. A.; Bertsch, D. L.; Chen, A. W.; Dingus, B. L.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Lin, Y. C.;

A New Determination of the Extragalactic Diffuse X-Ray Background from EGRET Data

NASA Technical Reports Server (NTRS)

Strong, Andrew W.; Moskalenko, Igor V.; Reimer, Olaf

2004-01-01

We use the GALPROP model for cosmic-ray propagation to obtain a new estimate of the Galactic component of gamma rays, and show that away from the Galactic plane it gives an accurate prediction of the observed EGRET intensities in the energy range 30 MeV - 50 GeV. On this basis we re-evaluate the extragalactic gamma-ray background. We find that for some energies previous work underestimated the Galactic contribution at high latitudes and hence overestimated the background. Our new background spectrum shows a positive curvature similar to that expected for models of the extragalactic emission based on the blazar population.

Physiological condition of juvenile wading birds in relation to multiple landscape stressors in the Florida Everglades: effects of hydrology, prey availability, and mercury bioaccumulation

USGS Publications Warehouse

Herring, Garth; Eagles-Smith, Collin A.; Gawlik, Dale E.; Beerens, James M.; Ackerman, Joshua T.

2014-01-01

The physiological condition of juvenile birds can be influenced by multiple ecological stressors, and few studies have concurrently considered the effects of environmental contaminants in combination with ecological attributes that can influence foraging conditions and prey availability. Using three temporally distinct indices of physiological condition, we compared the physiological response of nestling great egrets (Ardea alba) and white ibises (Eudocimus albus) to changing prey availability, hydrology (water depth, recession rate), and mercury exposure in the Florida Everglades. We found that the physiological response of chicks varied between species and among environmental variables. Chick body condition (short-term index) and fecal corticosterone levels (medium-term) were influenced by wetland water depth, prey availability, region, and age, but not by mercury contamination. However, mercury exposure did influence heat shock protein 70 (HSP70) in egret chicks, indicating a longer-term physiological response to contamination. Our results indicate that the physiological condition of egret and ibis chicks were influenced by several environmental stressors, and the time frame of the effect may depend on the specialized foraging behavior of the adults provisioning the chicks.

Physiological condition of juvenile wading birds in relation to multiple landscape stressors in the Florida Everglades: effects of hydrology, prey availability, and mercury bioaccumulation.

PubMed

Herring, Garth; Eagles-Smith, Collin A; Gawlik, Dale E; Beerens, James M; Ackerman, Joshua T

2014-01-01

The physiological condition of juvenile birds can be influenced by multiple ecological stressors, and few studies have concurrently considered the effects of environmental contaminants in combination with ecological attributes that can influence foraging conditions and prey availability. Using three temporally distinct indices of physiological condition, we compared the physiological response of nestling great egrets (Ardea alba) and white ibises (Eudocimus albus) to changing prey availability, hydrology (water depth, recession rate), and mercury exposure in the Florida Everglades. We found that the physiological response of chicks varied between species and among environmental variables. Chick body condition (short-term index) and fecal corticosterone levels (medium-term) were influenced by wetland water depth, prey availability, region, and age, but not by mercury contamination. However, mercury exposure did influence heat shock protein 70 (HSP70) in egret chicks, indicating a longer-term physiological response to contamination. Our results indicate that the physiological condition of egret and ibis chicks were influenced by several environmental stressors, and the time frame of the effect may depend on the specialized foraging behavior of the adults provisioning the chicks.

Physiological Condition of Juvenile Wading Birds in Relation to Multiple Landscape Stressors in the Florida Everglades: Effects of Hydrology, Prey Availability, and Mercury Bioaccumulation

PubMed Central

Herring, Garth; Eagles-Smith, Collin A.; Gawlik, Dale E.; Beerens, James M.; Ackerman, Joshua T.

2014-01-01

The physiological condition of juvenile birds can be influenced by multiple ecological stressors, and few studies have concurrently considered the effects of environmental contaminants in combination with ecological attributes that can influence foraging conditions and prey availability. Using three temporally distinct indices of physiological condition, we compared the physiological response of nestling great egrets (Ardea alba) and white ibises (Eudocimus albus) to changing prey availability, hydrology (water depth, recession rate), and mercury exposure in the Florida Everglades. We found that the physiological response of chicks varied between species and among environmental variables. Chick body condition (short-term index) and fecal corticosterone levels (medium-term) were influenced by wetland water depth, prey availability, region, and age, but not by mercury contamination. However, mercury exposure did influence heat shock protein 70 (HSP70) in egret chicks, indicating a longer-term physiological response to contamination. Our results indicate that the physiological condition of egret and ibis chicks were influenced by several environmental stressors, and the time frame of the effect may depend on the specialized foraging behavior of the adults provisioning the chicks. PMID:25184221

Search of the energetic gamma-ray experiment telescope (EGRET) data for high-energy gamma-ray microsecond bursts

NASA Technical Reports Server (NTRS)

Fichtel, C. E.; Bertsch, D. L.; Dingus, B. L.; Esposito, J. A.; Hartman, R. C.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Lin, Y. C.; Mattox, J. R.

1994-01-01

Hawking (1974) and Page & Hawking (1976) investigated theoretically the possibility of detecting high-energy gamma rays produced by the quantum-mechanical decay of a small black hole created in the early universe. They concluded that, at the very end of the life of the small black hole, it would radiate a burst of gamma rays peaked near 250 MeV with a total energy of about 10(exp 34) ergs in the order of a microsecond or less. The characteristics of a black hole are determined by laws of physics beyond the range of current particle accelerators; hence, the search for these short bursts of high-energy gamma rays provides at least the possibility of being the first test of this region of physics. The Compton Observatory Energetic Gamma-Ray Experiment Telescope (EGRET) has the capability of detecting directly the gamma rays from such bursts at a much fainter level than SAS 2, and a search of the EGRET data has led to an upper limit of 5 x 10(exp -2) black hole decays per cu pc per yr, placing constraints on this and other theories predicting microsecond high-energy gamma-ray bursts.

Five New Millisecond Pulsars From A Radio Survey Of 14 Unidentified Fermi -Lat Gamma-Ray Sources

DOE PAGES

Kerr, M.; Camilo, F.; Johnson, T. J.; ...

2012-02-27

We have discovered five millisecond pulsars (MSPs) in a survey of 14 unidentified Fermi-LAT sources in the southern sky using the Parkes radio telescope. PSRs J0101–6422, J1514–4946, and J1902–5105 reside in binaries, while PSRs J1658–5324 and J1747–4036 are isolated. Using an ephemeris derived from timing observations of PSR J0101–6422 (P=2.57ms, DM=12 pc cm -3), we have detected γ-ray pulsations and measured its proper motion. Its γ-ray spectrum (a power law of Γ = 0.9 with a cutoff at 1.6GeV) and efficiency are typical of other MSPs, but its radio and γ-ray light curves challenge simple geometric models of emission. Themore » high success rate of this survey—enabled by selecting γ- ray sources based on their detailed spectral characteristics—and other similarly successful searches indicate that a substantial fraction of the local population of MSPs may soon be known.« less

FIVE NEW MILLISECOND PULSARS FROM A RADIO SURVEY OF 14 UNIDENTIFIED FERMI-LAT GAMMA-RAY SOURCES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kerr, M.; Camilo, F.; Johnson, T. J.

2012-03-20

We have discovered five millisecond pulsars (MSPs) in a survey of 14 unidentified Fermi Large Area Telescope sources in the southern sky using the Parkes radio telescope. PSRs J0101-6422, J1514-4946, and J1902-5105 reside in binaries, while PSRs J1658-5324 and J1747-4036 are isolated. Using an ephemeris derived from timing observations of PSR J0101-6422 (P = 2.57 ms, DM = 12 pc cm{sup -3}), we have detected {gamma}-ray pulsations and measured its proper motion. Its {gamma}-ray spectrum (a power law of {Gamma} = 0.9 with a cutoff at 1.6 GeV) and efficiency are typical of other MSPs, but its radio and {gamma}-raymore » light curves challenge simple geometric models of emission. The high success rate of this survey-enabled by selecting {gamma}-ray sources based on their detailed spectral characteristics-and other similarly successful searches indicate that a substantial fraction of the local population of MSPs may soon be known.« less

The Distribution of Cosmic-Ray Sources in the Galaxy, Gamma-Rays and the Gradient in the CO-to-H2 Relation

NASA Technical Reports Server (NTRS)

Strong, A. W.; Moskalenko, I. V.; Reimer, O.; Diehl, S.; Diehl, R.

2004-01-01

We present a solution to the apparent discrepancy between the radial gradient in the diffuse Galactic gamma-ray emissivity and the distribution of supernova remnants, believed to be the sources of cosmic rays. Recent determinations of the pulsar distribution have made the discrepancy even more apparent. The problem is shown to be plausibly solved by a variation in the Wco-to-N(H2) scaling factor. If this factor increases by a factor of 5-10 from the inner to the outer Galaxy, as expected from the Galactic metallicity gradient and supported by other evidence, we show that the source distribution required to match the radial gradient of gamma-rays can be reconciled with the distribution of supernova remnants as traced by current studies of pulsars. The resulting model fits the EGRET gamma-ray profiles extremely well in longitude, and reproduces the mid-latitude inner Galaxy intensities better than previous models.

Avian Hepatitis E Virus in Chickens, Taiwan, 2013

PubMed Central

Hsu, Ingrid W.-Y.

2014-01-01

A previously unidentified strain of avian hepatitis E virus (aHEV) is now endemic among chickens in Taiwan. Analysis showed that the virus is 81.5%–86.5% similar to other aHEVs. In Taiwan, aHEV infection has been reported in chickens without aHEV exposure, suggesting transmission from asymptomatic cases or repeated introduction through an unknown common source(s). PMID:24378180

Low energy gamma ray emission from the Cygnus OB2 association

NASA Technical Reports Server (NTRS)

Chen, Wan; White, Richard L.

1992-01-01

According to our newly developed model of gamma-ray emission from chaotic early-type stellar winds, we predict the combined gamma-ray flux from the circumstellar winds of many very luminous early-type stars in the Cyg OB2 association can be detectable by the Energetic Gamma Ray Experiment Telescope (EGRET) (and maybe also by OSSE) on CGRO. Due to different radiation mechanisms, the gamma-ray spectrum from stellar winds can be quite different from that of CYG X-3; this spectral difference and the time-variation of Cyg X-3 flux will help to distinguish the gamma-ray components from different sources in this small region, which is spatially unresolvable by CGRO.

Gamma-ray emission from Cataclysmic variables. 1: The Compton EGRET survey

NASA Technical Reports Server (NTRS)

Schlegel, Eric M.; Barrett, Paul E.; De Jager, O. C.; Chanmugam, G.; Hunter, S.; Mattox, J.

1995-01-01

We report the results of the first gamma-ray survey of cataclysmic variables (CVs) using observations obtained with the Energetic Gamma Ray Experiment Telescope (EGRET) instrument on the Compton Observatory. We briefly describe the theoretical models that are applicable to gamma-ray emission from CVs. These models are particularly relevant to magnetic CVs containing asynchronously rotating white dwarfs. No magnetic CV was detected with an upper limit on the flux at 1 GeV of approximately 2 x 10(exp -8)/sq cm/sec, which corresponds to an upper limit on the gamma-ray luminosity of approximately 10(exp 31) ergs/sec, assuming a typical CV distance of 100 pc.

KSC-08pd4126

NASA Image and Video Library

2008-12-23

CAPE CANAVERAL, Fla. – A snowy egret stands in the shallow water of a pond in the Merritt island National Wildlife Refuge, which borders NASA's Kennedy Space Center in Florida. A type of heron, the snowy egret inhabits salt marshes, ponds, rice fields and shallow coastal bays ranging from Maine to southern South America on the east coast. It can also be found in California and Oklahoma to the Gulf of Mexico. The center shares a boundary with the refuge that includes salt-water estuaries, brackish marshes, hardwood hammocks and pine flatwoods. The diverse landscape provides habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. Photo credit: NASA/Jim Grossmann

Unveiling the nature of INTEGRAL objects through optical spectroscopy. VI. A multi-observatory identification campaign

NASA Astrophysics Data System (ADS)

Masetti, N.; Mason, E.; Morelli, L.; Cellone, S. A.; McBride, V. A.; Palazzi, E.; Bassani, L.; Bazzano, A.; Bird, A. J.; Charles, P. A.; Dean, A. J.; Galaz, G.; Gehrels, N.; Landi, R.; Malizia, A.; Minniti, D.; Panessa, F.; Romero, G. E.; Stephen, J. B.; Ubertini, P.; Walter, R.

2008-04-01

Using 8 telescopes in the northern and southern hemispheres, plus archival data from two on-line sky surveys, we performed a systematic optical spectroscopic study of 39 putative counterparts of unidentified or poorly studied INTEGRAL sources in order to determine or at least better assess their nature. This was implemented within the framework of our campaign to reveal the nature of newly-discovered and/or unidentified sources detected by INTEGRAL. Our results show that 29 of these objects are active galactic nuclei (13 of which are of Seyfert 1 type, 15 are Seyfert 2 galaxies and one is possibly a BL Lac object) with redshifts between 0.011 and 0.316, 7 are X-ray binaries (5 with high-mass companions and 2 with low-mass secondaries), one is a magnetic cataclysmic variable, one is a symbiotic star and one is possibly an active star. Thus, the large majority (74%) of the identifications in this sample belongs to the AGN class. When possible, the main physical parameters for these hard X-ray sources were also computed using the multiwavelength information available in the literature. These identifications further underscore the importance of INTEGRAL in studying the hard X-ray spectra of all classes of X-ray emitting objects, and the effectiveness of a strategy of multi-catalogue cross-correlation plus optical spectroscopy to securely pinpoint the actual nature of still unidentified hard X-ray sources. Based on observations collected at the following observatories: ESO (La Silla, Chile), partly under program 079.A-0171(A); Astronomical Observatory of Bologna in Loiano (Italy); Astronomical Observatory of Asiago (Italy); Cerro Tololo Interamerican Observatory (Chile); Complejo Astronómico El Leoncito (San Juan, Argentina); South African Astronomical Observatory (Sutherland, South Africa); Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias (Canary Islands, Spain); Anglo-Australian Observatory (Siding Spring, Australia); Apache Point Observatory (New Mexico, USA).

Observations of the Crab pulsar and nebula by the EGRET telescope on the Compton Gamma-Ray Observatory

NASA Technical Reports Server (NTRS)

Nolan, P. L.; Arzoumanian, Z.; Bertsch, D. L.; Chiang, J.; Fichtel, C. E.; Fierro, J. M.; Hartman, R. C.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.

1993-01-01

The Crab pulsar and nebula were observed three times in 1991 April to June by the Energetic Gamma-Ray Experiment Telescope (EGRET) on the Compton Gamma-Ray Observatory (CGRO): April 23 to May 7, May 16 to 30, and June 8 to 15. The results of analysis of the gamma-ray emission in the energy range from 50 MeV to more than 10 GeV are reported. The observed gamma-ray light curve exhibits two peaks separated in phase by 0.40 +/- 0.02, consistent with previous observations. The total pulsed emission from the Crab pulsar is found to be well represented by a power-law spectrum, softer than the spectrum measured by COS B (Clear et al., 1987). The interpulse emission has a harder spectrum than either of the pulses. The evidence for pulsed emission above 5 GeV in the EGRET data is not conclusive. Unpulsed emission in the energy range 50 MeV to 5 GeV was detected, with an indication of a hardening of the unpulsed spectrum above about 1 GeV. There was a significant change in the light curve over the 2 months of these observations, although the shape of the spectrum remained constant.

Multi-Epoch Multiwavelength Spectra and Models for Blazar 3C 279

NASA Technical Reports Server (NTRS)

Hartman, R. C.; Boettcher, M.; Aldering, G.; Aller, H.; Aller, M.; Backman, D. E.; Balonek, T. J.; Bertsch, D. L.; Bloom, S. D.; Bock, H.;

VizieR Online Data Catalog: New gamma-ray blazar candidates in the 3PBC (Maselli+, 2013)

NASA Astrophysics Data System (ADS)

Maselli, A.; Massaro, F.; Cusumano, G.; D'Abrusco, R.; La Parola, V.; Paggi, A.; Segreto, A.; Smith, H. A.; Tosti, G.

2013-06-01

We searched for γ-ray blazar candidates among the 382 unidentified hard X-ray sources of the third Palermo BAT Catalog (3PBC) obtained from the analysis of 66 months of Swift Burst Alert Telescope (BAT) survey data and listing 1586 sources. We adopted a recently developed association method based on the peculiar infrared colors that characterize the γ-ray blazars included in the second catalog of active galactic nuclei detected by the Fermi Large Area Telescope. We used this method exploiting the data of the all-sky survey performed by the Wide-field Infrared Survey Explorer (WISE) to establish correspondences between unidentified 3PBC sources and WISE γ-ray blazar candidates located within the BAT positional uncertainty region at a 99% confidence level. We obtained a preliminary list of candidates for which we analyzed all the available data in the Swift archive to complement the information in the literature and in the radio, infrared, and optical catalogs with the information on their optical-UV and soft X-ray emission. Requiring the presence of radio and soft X-ray counterparts consistent with the infrared positions of the selected WISE sources, as well as a blazar-like radio morphology, we finally obtained a list of 24 γ-ray blazar candidates. (2 data files).

Searching for New γ-Ray Blazar Candidates in the Third Palermo BAT Hard X-Ray Catalog with WISE

NASA Astrophysics Data System (ADS)

Maselli, A.; Massaro, F.; Cusumano, G.; D'Abrusco, R.; La Parola, V.; Paggi, A.; Segreto, A.; Smith, Howard A.; Tosti, G.

2013-06-01

We searched for γ-ray blazar candidates among the 382 unidentified hard X-ray sources of the third Palermo BAT Catalog (3PBC) obtained from the analysis of 66 months of Swift Burst Alert Telescope (BAT) survey data and listing 1586 sources. We adopted a recently developed association method based on the peculiar infrared colors that characterize the γ-ray blazars included in the second catalog of active galactic nuclei detected by the Fermi Large Area Telescope. We used this method exploiting the data of the all-sky survey performed by the Wide-field Infrared Survey Explorer (WISE) to establish correspondences between unidentified 3PBC sources and WISE γ-ray blazar candidates located within the BAT positional uncertainty region at a 99% confidence level. We obtained a preliminary list of candidates for which we analyzed all the available data in the Swift archive to complement the information in the literature and in the radio, infrared, and optical catalogs with the information on their optical-UV and soft X-ray emission. Requiring the presence of radio and soft X-ray counterparts consistent with the infrared positions of the selected WISE sources, as well as a blazar-like radio morphology, we finally obtained a list of 24 γ-ray blazar candidates.

Mercury and drought along the lower Carson River, Nevada: IV. Snowy egret post-fledging dispersal, timing of migration and survival, 2002–2004

USGS Publications Warehouse

Henny, Charles J.; Hill, Elwood F.; Grove, Robert A.; Chelgren, Nathan; Haggerty, Patricia K.

2017-01-01

This telemetry study is an extension of our 1997–2006 research on historical mercury contamination on snowy egrets (Egretta thula) up to ~ 20 days of age. Findings from initial studies at the mercury-contaminated Carson River colony at Lahontan Reservoir (LR) and a similar-sized reference (REF) colony on the Humboldt River included mercury-related physiological, biochemical, histopathological and reproductive effects up to ~20 days of age; with poor water years (2000–04), i.e., reduced prey availability, exacerbating effects. Herein, we compare timing of dispersal and migration at LR vs. REF, but the primary question now addressed is “whether survival of young mercury-exposed snowy egrets from LR would be further compromised beyond ~20 days of age? ” Based upon telemetry signals until 90–110 days of age (including dead bird counts and survival rate estimates), we conclude that mercury did not further compromise survival. Dead bird counts and survival rate estimates included time in the colony when fed by adults, plus the critical period when young dispersed from the colony to forage independently. The extended drought during this 3-year study was most critical in 2002 when production of ~20 d old egrets at LR was only 0.24 young/nest. In 2002, survival rates were low at both colonies and we documented the highest counts of dead egrets for both colonies. We suggest the losses in 2002 beyond 20 days of age were more a function of prey availability influenced by drought than exposure to mercury, especially at LR, because higher mercury concentrations, higher survival rates and fewer dead birds were documented at LR in 2003 when water conditions improved. Furthermore, total mercury (THg) in blood in 2003 was more than double 2002 (geometric mean, 3.39 vs 1.47 µg/g wet weight (ww). This higher THg exposure at LR in 2003 was associated with a redistribution of parent and post-dispersal feeding activities upstream (where there was higher mercury from historic mining) related to slightly improved water levels. When comparing the 3-year telemetry findings based upon ~20 d old young at LR (blood THg, geo. means 1.47, 3.39 and 1.89 µg/g ww), we found no evidence that age at dispersal, Julian date at dispersal, timing of migration, or pre-migration survival (~20 to ~100 days post-hatch) were adversely affected by elevated mercury.

Mercury and drought along the lower Carson River, Nevada: IV. Snowy egret post-fledging dispersal, timing of migration and survival, 2002-2004.

PubMed

Henny, Charles J; Hill, Elwood F; Grove, Robert A; Chelgren, Nathan D; Haggerty, Patricia K

2017-01-01

This telemetry study is an extension of our 1997-2006 research on historical mercury contamination on snowy egrets (Egretta thula) up to ~ 20 days of age. Findings from initial studies at the mercury-contaminated Carson River colony at Lahontan Reservoir (LR) and a similar-sized reference (REF) colony on the Humboldt River included mercury-related physiological, biochemical, histopathological and reproductive effects up to ~20 days of age; with poor water years (2000-04), i.e., reduced prey availability, exacerbating effects. Herein, we compare timing of dispersal and migration at LR vs. REF, but the primary question now addressed is "whether survival of young mercury-exposed snowy egrets from LR would be further compromised beyond ~20 days of age? " Based upon telemetry signals until 90-110 days of age (including dead bird counts and survival rate estimates), we conclude that mercury did not further compromise survival. Dead bird counts and survival rate estimates included time in the colony when fed by adults, plus the critical period when young dispersed from the colony to forage independently. The extended drought during this 3-year study was most critical in 2002 when production of ~20d old egrets at LR was only 0.24 young/nest. In 2002, survival rates were low at both colonies and we documented the highest counts of dead egrets for both colonies. We suggest the losses in 2002 beyond 20 days of age were more a function of prey availability influenced by drought than exposure to mercury, especially at LR, because higher mercury concentrations, higher survival rates and fewer dead birds were documented at LR in 2003 when water conditions improved. Furthermore, total mercury (THg) in blood in 2003 was more than double 2002 (geometric mean, 3.39 vs 1.47µg/g wet weight (ww). This higher THg exposure at LR in 2003 was associated with a redistribution of parent and post-dispersal feeding activities upstream (where there was higher mercury from historic mining) related to slightly improved water levels. When comparing the 3-year telemetry findings based upon ~20d old young at LR (blood THg, geo. means 1.47, 3.39 and 1.89µg/g ww), we found no evidence that age at dispersal, Julian date at dispersal, timing of migration, or pre-migration survival (~20 to ~100 days post-hatch) were adversely affected by elevated mercury. Published by Elsevier Inc.

An energy-circuit population model for great egrets (Ardea alba) at Lake Okeechobee, Florida, U.S.A

USGS Publications Warehouse

Smith, Jeff P.

1997-01-01

I simulated the annual population cycles of Great Egrets (Ardea alba) at Lake Okeechobee, Florida, to provide a framework for evaluating the local population dynamics of nesting and foraging wading birds. The external forcing functions were solar energy, minimum air temperature, water depth, surface-water drying rate, and season. Solar input controlled the production of prey at moderate to high lake stages, but water area exerted primary control during a two-year drought. Modeling prey production as a linear function of water area resulted in underestimation of prey density during the drought, suggesting that prey organisms maintained high fecundity while concentrated in submerged vegetation at the lakeward fringe of the littoral zone. Simulation confirmed that large influxes of wading birds during the drought were the combined result of a regional refuge response and the availability of concentrated prey. Modeling immigration and emigration as primarily functions of the surface-water drying rate, rather than lake stage, resulted in a closer match of observed and simulated population trends for foraging birds, suggesting that the pattern of surface-water fluctuations was a more important factor than water depth. Simulation indicated an abrupt-threshold response rather than a linear association between foraging efficiency and low temperatures, which reduce activity levels of forage fishes. Great Egret breeder recruitment is primarily a function of prey availability, climate, and hydrologic trends, but simulation confirmed the concurrent involvement of a seasonal or physiological-readiness factor. An attractor function driven by high winter lake stages was necessary to reproduce observed patterns of breeder recruitment, suggesting that Great Egrets initiate nesting based on environmental cues that lead to peak food availability when nestlings are present. Poor correspondence of reproductive effort and nest productivity suggested that the drought compromised the birds' predictive abilities. The need to model breeder recruitment as a function of a maximum rate rather than the size of the local foraging population suggested that birds may nest on the lake even though on-lake foraging conditions are poor. Simulated and observed estimates of egg and hatching production did not match, suggesting that the causes of failure during incubation were complex or more localized than could be accounted for with lakewide hydrologic and climatic data. A forced increase in prey consumption of 12% was necessary to reproduce observed, high levels of nest productivity in 1990, which corresponded to the finding that panhandled fish constituted 10–12% of the biomass fed to Great Egret nestlings that year.

INTEGRATED TECHNOLOGY-BASED TOXICOLOGY STUDIES ON DRINKING WATER DISINFECTION BYPRODUCTS (DBPS)

EPA Science Inventory

DBPs are formed by reactions of chemical disinfectants with natural organic matter in the source water. Although more than 300 DBPs are known, many remain unidentified; for chlorination, known DBPs account for ~50% of the mass of total organic halide. Toxicological evaluation o...

Detection of the aromatic molecule benzonitrile (c-C6H5CN) in the interstellar medium

NASA Astrophysics Data System (ADS)

McGuire, Brett A.; Burkhardt, Andrew M.; Kalenskii, Sergei; Shingledecker, Christopher N.; Remijan, Anthony J.; Herbst, Eric; McCarthy, Michael C.

2018-01-01

Polycyclic aromatic hydrocarbons and polycyclic aromatic nitrogen heterocycles are thought to be widespread throughout the universe, because these classes of molecules are probably responsible for the unidentified infrared bands, a set of emission features seen in numerous Galactic and extragalactic sources. Despite their expected ubiquity, astronomical identification of specific aromatic molecules has proven elusive. We present the discovery of benzonitrile (c-C6H5CN), one of the simplest nitrogen-bearing aromatic molecules, in the interstellar medium. We observed hyperfine-resolved transitions of benzonitrile in emission from the molecular cloud TMC-1. Simple aromatic molecules such as benzonitrile may be precursors for polycyclic aromatic hydrocarbon formation, providing a chemical link to the carriers of the unidentified infrared bands.

KSC-07pd0876

NASA Image and Video Library

2007-04-11

KENNEDY SPACE CENTER, FLA. -- A snowy egret perches on dead limbs in the Indian River near Kennedy Space Center. A type of heron, the snowy egret inhabits salt marshes, ponds, rice fields and shallow coastal bays ranging from Maine to southern South America on the east coast. It can also be found in California and Oklahoma to the Gulf of Mexico. KSC shares a boundary with the Merritt Island Wildlife Nature Refuge. The refuge is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. In addition, the Refuge supports 19 endangered or threatened wildlife species on Federal or State lists, more than any other single refuge in the U.S. Photo credit: NASA/Dimitri Gerondidakis

KSC-05PD-1018

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. Snowy egrets join in a feeding frenzy in a marshy area of the Merritt Island National Wildlife Refuge. Ranging from northern California, Oklahoma and Maine to southern South America, the snowy egret winters north to California and South Carolina. In the East, they are best known as salt marsh birds. Once an endangered species, their numbers have increased. The refuge was established in 1963 on Kennedy Space Center land and water not used by NASA for the space program. The marshes and open water of the refuge provide wintering grounds for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

KSC-07pd0151

NASA Image and Video Library

2007-01-19

KENNEDY SPACE CENTER, FLA. -- A snowy egret is spotted in the midst of reeds near a pond on NASA's Kennedy Space Center. A type of heron, the snowy egret inhabits salt marshes, ponds, rice fields and shallow coastal bays ranging from Maine to southern South America on the east coast. It can also be found in California and Oklahoma to the Gulf of Mexico. KSC shares a boundary with the Merritt Island Wildlife Nature Refuge. The refuge is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. In addition, the Refuge supports 19 endangered or threatened wildlife species on Federal or State lists, more than any other single refuge in the U.S. Photo credit: NASA/Ken Thornsley

KSC-07pd0878

NASA Image and Video Library

2007-04-11

KENNEDY SPACE CENTER, FLA. -- A snowy egret prepares for flight from its perch in the Indian River near Kennedy Space Center. A type of heron, the snowy egret inhabits salt marshes, ponds, rice fields and shallow coastal bays ranging from Maine to southern South America on the east coast. It can also be found in California and Oklahoma to the Gulf of Mexico. KSC shares a boundary with the Merritt Island Wildlife Nature Refuge. The refuge is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. In addition, the Refuge supports 19 endangered or threatened wildlife species on Federal or State lists, more than any other single refuge in the U.S. Photo credit: NASA/Dimitri Gerondidakis

KSC-07pd0877

NASA Image and Video Library

2007-04-11

KENNEDY SPACE CENTER, FLA. -- A snowy egret perches on dead limbs in the Indian River near Kennedy Space Center. A type of heron, the snowy egret inhabits salt marshes, ponds, rice fields and shallow coastal bays ranging from Maine to southern South America on the east coast. It can also be found in California and Oklahoma to the Gulf of Mexico. KSC shares a boundary with the Merritt Island Wildlife Nature Refuge. The refuge is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. In addition, the Refuge supports 19 endangered or threatened wildlife species on Federal or State lists, more than any other single refuge in the U.S. Photo credit: NASA/Dimitri Gerondidakis

KSC-07pd0726

NASA Image and Video Library

2007-03-29

KENNEDY SPACE CENTER, FLA. -- A snowy egret marches through a pond near Kennedy Space Center, looking for food. The snowy egret can be identified by its slender black bill, black legs and yellow feet. This species inhabits salt marshes, ponds, rice field and shallow coastal bays along the coast from Maine to southern South America. They are also found in northern California, Texas and Oklahoma. KSC shares a boundary with the Merritt Island National Wildlife Refuge, which surrounds it. The refuge is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. In addition, the refuge supports 19 endangered or threatened wildlife species on Federal or State lists, more than any other single refuge in the U.S. Photo credit: NASA/Ken Thornsley

KSC-07pd0153

NASA Image and Video Library

2007-01-19

KENNEDY SPACE CENTER, FLA. -- A snowy egret is on the lookout for food in a pond on NASA's Kennedy Space Center. A type of heron, the snowy egret inhabits salt marshes, ponds, rice fields and shallow coastal bays ranging from Maine to southern South America on the east coast. It can also be found in California and Oklahoma to the Gulf of Mexico. KSC shares a boundary with the Merritt Island Wildlife Nature Refuge. The refuge is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. In addition, the Refuge supports 19 endangered or threatened wildlife species on Federal or State lists, more than any other single refuge in the U.S. Photo credit: NASA/Ken Thornsley

Common Knowledge, Learning, and Citation Practices in University Writing

ERIC Educational Resources Information Center

Shi, Ling

2011-01-01

The present study is based on interviews of students (n = 48) and instructors (n = 27) from various disciplines in a North American research university and explores participants' comments on examples of some students' unacknowledged texts appropriated and drawn from published sources, classroom learning, or unidentified prior reading. Although…

Commentary: What the Press Can Do to Meet Public Expectations.

ERIC Educational Resources Information Center

Martin, Harold E.

1980-01-01

Discusses trends and concerns in news reporting and news writing, including the accuracy of investigative reporting, the increased use of news "leaks" and unidentified sources, and the need to orient newspaper content toward real people with real interests instead of writing for an "average" reader. (RL)

MAGIC: First Observational Results and Perspectives for Future Developments

NASA Astrophysics Data System (ADS)

Hengstebeck, T.; Kalekin, O.; Merck, M.; Mirzoyan, R.; Pavel, N.; Schweizer, T.; Shayduk, M.; MAGIC Collaboration

The MAGIC (Major Atmospheric Gamma Imaging Cherenkov) telescope was designed to close the energy gap (~ 10-250 GeV) between ground based and satellite gamma detectors. It is situated on the Roque de los Muchachos, La Palma, Canary Islands at altitude of 2200 m. The main subjects of the investigations with the telescope are: Gamma Ray Bursts, Supernova Remnants, Plerions, Pulsars, Active Galactic Nuclei (AGNs), unidentied EGRET sources, Dark matter and Quantum gravity. More details about physics with a low threshold gamma ray telescope one can nd in [2]. The telescope hardware installation was nished in October 2003. Since that time the observations of the dierent classes of objects have been carried out but the experiment is still in the commission phase.

The 3C 279 Campaign of Winter 1999: A Gamma-Optical Correlation?

NASA Technical Reports Server (NTRS)

Hartman, R. C.; Villata, M.; Raiteri, C. M.; Sobrito, M.; DeFrancesco, G.; Ostorero, L.; Tosti, G.; Kurtanidze, O.; Nikolashvili, M.; Takalo, L.

2000-01-01

Preliminary results are presented from the gamma-optical campaign of January-February 1999 on 3C 279. During this period we obtained good optical sampling of the source, the best ever for a gamma-bright OVV quasar. Its large and fast variations have been compared with the gamma-ray fluxes obtained simultaneously by Energy Gamma Ray Experiment Telescope (EGRET), on Compton Gamma Ray Observatory (CGRO). Despite rather poor counting statistics in the gamma-ray data, a fair correlation is found, with the gamma variations following those in the optical by 3-4 days. This is the first time such a significant day-scale correlation has been observed between the optical and gamma emissions from a OVV quasar. Its implications are currently under study.

HESS J1943+213: A candidate extreme BL Lacertae object

DOE PAGES

Abramowski, A.; Acero, F.; Aharonian, F.; ...

2011-03-30

In this paper, we report on a newly detected point-like source, HESS J1943+213. This source coincides with an unidentified hard X-ray source IGR J19443+2117, which was proposed to have radio and infrared counterparts. Here, we combine new H.E.S.S., Fermi/LAT and Nançay Radio Telescope observations with pre-existing non-simultaneous multi-wavelength observations of IGR J19443+2117 and discuss the likely source associations as well as the interpretation as an active galactic nucleus, a gamma-ray binary or a pulsar wind nebula.

A SEARCH FOR RAPIDLY SPINNING PULSARS AND FAST TRANSIENTS IN UNIDENTIFIED RADIO SOURCES WITH THE NRAO 43 METER TELESCOPE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmidt, Deborah; Crawford, Fronefield; Gilpin, Claire

2013-04-15

We have searched 75 unidentified radio sources selected from the NRAO VLA Sky Survey catalog for the presence of rapidly spinning pulsars and short, dispersed radio bursts. The sources are radio bright, have no identifications or optical source coincidences, are more than 5% linearly polarized, and are spatially unresolved in the catalog. If these sources are fast-spinning pulsars (e.g., sub-millisecond pulsars), previous large-scale pulsar surveys may have missed detection due to instrumental and computational limitations, eclipsing effects, or diffractive scintillation. The discovery of a sub-millisecond pulsar would significantly constrain the neutron star equation of state and would have implications formore » models predicting a rapid slowdown of highly recycled X-ray pulsars to millisecond periods from, e.g., accretion disk decoupling. These same sources were previously searched unsuccessfully for pulsations at 610 MHz with the Lovell Telescope at Jodrell Bank. This new search was conducted at a different epoch with a new 800 MHz backend on the NRAO 43 m Telescope at a center frequency of 1200 MHz. Our search was sensitive to sub-millisecond pulsars in highly accelerated binary systems and to short transient pulses. No periodic or transient signals were detected from any of the target sources. We conclude that diffractive scintillation, dispersive smearing, and binary acceleration are unlikely to have prevented detection of the large majority of the sources if they are pulsars, though we cannot rule out eclipsing, nulling or intermittent emission, or radio interference as possible factors for some non-detections. Other (speculative) possibilities for what these sources might include radio-emitting magnetic cataclysmic variables or older pulsars with aligned magnetic and spin axes.« less

Possible new VY Scl-type variable 1RXS J075330.1+044606

NASA Astrophysics Data System (ADS)

Sokolovsky, K.; Denisenko, D.; Mescheryakov, A.; Tkachenko, A.; Korotkiy, S.; Gerke, V.

2012-02-01

We report the discovery of a possible new VY Scl-type cataclysmic variable associated with previously unidentified X-ray source 1RXS J075330.1+044606. The variable optical object USNO-B1.0 0947-0148659 (07:53:30.78 +04:45:56.3, J2000) located 15" from the X-ray source listed in the ROSAT All Sky Survey Faint Source Catalog (Voges et al., 2000, IAUC, 7432) was identified from information listed in the USNO-B1.0 catalog (Monet et al.

Organochlorines and mercury in eggs of coastal terns and herons in California, USA

USGS Publications Warehouse

Ohlendorf, H.M.; Custer, T.W.; Lowe, Roy W.; Rigney, M.; Cromartie, E.

1988-01-01

In San Franciso Bay, California, USA, concentrations of DDE and mercury in eggs differed among Caspian Tern, Forster's Tern, Black-crowned Night-Heron, and Snowy Egret in 1982. Geometric mean DDE concentrations were higher (P < 0.05) in Caspian Tern eggs (6.93 ppm, wet weight) than in eggs of other species (1.92-2.84 ppm). Mean mercury concentrations were significantly greater in Caspian Tern (1.25 ppm) and forster's Tern (0.90 ppm) eggs than in night-herons (0.41 ppm), but night-heron eggs contained higher concentrations of mercury than did the eggs of Snowy Egrets (0.21 ppm). There were no significant differences among species for mean concentrations of trans-nonachlor or PCBs; other organochlorines occurred in fewer than half of the samples, so means were not compared. Caspian Tern eggs from San Francisco Bay had higher PCB concentrations (4.85 ppm) than did eggs of this species from San Diego Bay, California (1.70 ppm) or Elkhorn Slough, California (1.83 ppm), but we detected no significant differences in mean concentrations of other organochlorines. DDE concentrations in 5 of 47 (10.6%) night-heron eggs from San Francisco Bay exceeded 8 ppm, a level associated with impaired reproduction in this species. DDE concentrations were negatively correlated with eggshell thickness in night-herons and egrets.

Eustrongylidosis

USGS Publications Warehouse

Cole, Rebecca A.

1999-01-01

Eustrongylidosis is caused by the nematodes or roundworms Eustrongylides tubifex, E. ignotus, and E. excisus. Eustrongylides sp. can cause large die-offs of nestlings in coastal rookeries, especially of egrets and other wading birds.

Deep View of the Large Magellanic Cloud with Six Years of Fermi-LAT Observations

NASA Technical Reports Server (NTRS)

Ackermann, M.; Albert, A.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Bloom, E. D.;

Deep view of the Large Magellanic Cloud with six years of Fermi -LAT observations

DOE PAGES

Ackermann, M.

2016-01-27

Context. The nearby Large Magellanic Cloud (LMC) provides a rare opportunity of a spatially resolved view of an external star-forming galaxy in -rays. The LMC was detected at 0.1–100 GeV as an extended source with CGRO/EGRET and using early observations with the Fermi-LAT. The emission was found to correlate with massive star-forming regions and to be particularly bright towards 30 Doradus. Aims. Studies of the origin and transport of cosmic rays (CRs) in the Milky Way are frequently hampered by line-of-sight confusion and poor distance determination. The LMC offers a complementary way to address these questions by revealing whether andmore » how the -ray emission is connected to specific objects, populations of objects, and structures in the galaxy. Methods. We revisited the -ray emission from the LMC using about 73 months of Fermi-LAT P7REP data in the 0.2–100 GeV range. We developed a complete spatial and spectral model of the LMC emission, for which we tested several approaches: a simple geometrical description, template-fitting, and a physically driven model for CR-induced interstellar emission. Results. In addition to identifying PSR J0540-6919 through its pulsations, we find two hard sources positionally coincident with plerion N 157B and supernova remnant N 132D, which were also detected at TeV energies with H.E.S.S. We detect an additional soft source that is currently unidentified. Extended emission dominates the total flux from the LMC. It consists of an extended component of about the size of the galaxy and additional emission from three to four regions with degree-scale sizes. If it is interpreted as CRs interacting with interstellar gas, the large-scale emission implies a large-scale population of ~1–100GeV CRs with a density of ~30% of the local Galactic value. On top of that, the three to four small-scale emission regions would correspond to enhancements of the CR density by factors 2 to 6 or higher, possibly more energetic and younger populations of CRs compared to the large-scale population. An alternative explanation is that this is emission from an unresolved population of at least two dozen objects, such as pulsars and their nebulae or supernova remnants. This small-scale extended emission has a spatial distribution that does not clearly correlate with known components of the LMC, except for a possible relation to cavities and supergiant shells. Conclusions. The Fermi-LAT GeV observations allowed us to detect individual sources in the LMC. Three of the newly discovered sources are associated with rare and extreme objects. The 30 Doradus region is prominent in GeV -rays because PSR J0540-6919 and N 157B are strong emitters. The extended emission from the galaxy has an unexpected spatial distribution, and observations at higher energies and in radio may help to clarify its origin. Key words. Gamma« less

SEARCHING FOR NEW {gamma}-RAY BLAZAR CANDIDATES IN THE THIRD PALERMO BAT HARD X-RAY CATALOG WITH WISE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maselli, A.; Cusumano, G.; La Parola, V.

We searched for {gamma}-ray blazar candidates among the 382 unidentified hard X-ray sources of the third Palermo BAT Catalog (3PBC) obtained from the analysis of 66 months of Swift Burst Alert Telescope (BAT) survey data and listing 1586 sources. We adopted a recently developed association method based on the peculiar infrared colors that characterize the {gamma}-ray blazars included in the second catalog of active galactic nuclei detected by the Fermi Large Area Telescope. We used this method exploiting the data of the all-sky survey performed by the Wide-field Infrared Survey Explorer (WISE) to establish correspondences between unidentified 3PBC sources andmore » WISE {gamma}-ray blazar candidates located within the BAT positional uncertainty region at a 99% confidence level. We obtained a preliminary list of candidates for which we analyzed all the available data in the Swift archive to complement the information in the literature and in the radio, infrared, and optical catalogs with the information on their optical-UV and soft X-ray emission. Requiring the presence of radio and soft X-ray counterparts consistent with the infrared positions of the selected WISE sources, as well as a blazar-like radio morphology, we finally obtained a list of 24 {gamma}-ray blazar candidates.« less

Finding the rarest objects in the universe: A new, efficient method for discovering BL Lacertae objects

NASA Technical Reports Server (NTRS)

Stocke, John; Perlman, Eric; Granados, Arno; Schachter, Jonathan; Elvis, Martin; Urry, Meg; Impey, Chris; Smith, Paul

1993-01-01

We present a new, efficient method for discovering new BL Lac Objects based upon the results of the Einstein Extended Medium Sensitivity Survey (EMSS). We have found that all x-ray selected BL Lacs are radio emitters, and further, that in a 'color-color' diagram (radio/optical and optical/x-ray) the BL Lac Objects occupy an area distinct from both radio loud quasars and the radio quiet QSOs and Seyferts which dominate x-ray selected samples. After obtaining radio counterparts via VLA 'snapshot' observations of a large sample of unidentified x-ray sources, the list of candidates is reduced. These candidates then can be confirmed with optical spectroscopy and/or polarimetry. Since greater than 70 percent of these sources are expected to be BL Lacs, the optical observations are very efficient. We have tested this method using unidentified sources found in the Einstein Slew Survey. The 162 Slew Survey x-ray source positions were observed with the VLA in a mixed B/C configuration at 6 cm resulting in 60 detections within 1.5 position error circle radii. These x-ray/optical/radio sources were then plotted, and 40 BL Lac candidates were identified. To date, 10 candidates have been spectroscopically observed resulting in 10 new BL Lac objects! Radio flux, optical magnitude, and polarization statistics (obtained in white light with the Steward Observatory 2.3 m CCD polarimeter) for each are given.

KSC-2012-6482

NASA Image and Video Library

2012-12-19

CAPE CANAVERAL, Fla. – A great egret stands in the march at the Blackpoint Wildlife Drive in the Merritt Island National Wildlife Refuge, northwest of NASA's Kennedy Space Center in Florida. Kennedy Space Center shares a boundary with the Merritt Island National Wildlife Refuge. The Refuge encompasses 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects. For more information, visit: http://www.nasa.gov/centers/kennedy/shuttleoperations/alligators/kscovr.html Photo credit: NASA/Jim Grossmann

A search for interstellar nitrous oxide

NASA Technical Reports Server (NTRS)

Wilson, W. J.; Snyder, L. E.

1981-01-01

An extensive search for interstellar nitrous oxide (N2O) has been made at two different frequencies, 75.4 and 100.5 GHz, in a number of molecular sources. No N2O signal was detected; however, a number of other spectral lines including two new transitions of methyl formate and several new unidentified lines were measured.

Multi-wavelength studies of Redback and Black Widow pulsars

NASA Astrophysics Data System (ADS)

Mignani, Roberto; Salvetti, David; Pallanca, Cristina; Marelli, Martino; De Luca, Andrea; Belfiore, Andrea Mario

2016-07-01

The unexpected Fermi discovery of more than 70 gamma-ray milli-second pulsars (MSPs) outside globular clusters, spurred the scientific interest on these objects, and opened new horizons in MSP astronomy and on the study of the evolution of neutron stars in compact binary systems, including the ablation process of the companion star in the so-called Black Widow (BW) and Redback (RB) systems. It is thought that an important fraction of the tens of unidentified pulsar-like Fermi sources at high latitude are MSPs, yet unidentified, owing to their extremely elusive radio emission. As shown in a few recent cases, optical observations have been instrumental to spot binary MSP candidates through the discovery of periodic modulations in the flux of their putative companions. In this contribution, we report on the recent follow-ups of several candidate binary MSPs carried out with optical and X-ray facilities, e.g. GROND and XMM-Newton, Swift. This program already lead to identification of the Fermi source 3FGL 2036.6-5618 as candidate RB system, through the detection of periodic (orbital) modulation of its X/optical flux (Salvetti et al. 2015).

VizieR Online Data Catalog: Gamma-ray bright blazars spectrophotometry (Williamson+, 2014)

NASA Astrophysics Data System (ADS)

Williamson, K. E.; Jorstad, S. G.; Marscher, A. P.; Larionov, V. M.; Smith, P. S.; Agudo, I.; Arkharov, A. A.; Blinov, D. A.; Casadio, C.; Efimova, N. V.; Gomez, J. L.; Hagen-Thorn, V. A.; Joshi, M.; Konstantinova, T. S.; Kopatskaya, E. N.; Larionova, E. G.; Larionova, L. V.; Malmrose, M. P.; McHardy, I. M.; Molina, S. N.; Morozova, D. A.; Schmidt, G. D.; Taylor, B. W.; Troitsky, I. S.

2017-03-01

Since 2007, we have been collecting multi-waveband fluxes, polarization measurements, and radio images of blazars to provide the data for understanding the physics of the jets (see, e.g., Marscher 2012, arXiv:1201.5402). This study includes 28 of the original 30 objects selected for the monitoring campaign, confirmed as γ-ray sources by EGRET (Energetic γ-Ray Experiment Telescope) on the Compton Gamma Ray Observatory, have an R-band brightness exceeding 18 mag (bright enough for optical polarization measurements at a 1-2 m class optical telescope without needing excessive amounts of telescope time), exceed 0.5 Jy at 43 GHz, and have a declination accessible to the collaboration's observatories (> - 30°). Three additional BL Lacs (1055+018, 1308+326, and 1749+096) and two FSRQs (3C345 and 3C446) included in this analysis were among those added when they were detected as γ-ray sources by the Fermi LAT (Abdo et al. 2009, J/ApJ/700/597). (4 data files).

FERMI Observations of TeV-Selected Active Galactic Nuclei

DOE PAGES

Abdo, A. A.; Ackermann, M.; Ajello, M.; ...

2009-12-04

Here, we report on observations of TeV-selected active galactic nuclei (AGNs) made during the first 5.5 months of observations with the Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope (Fermi). In total, 96 AGNs were selected for study, each being either (1) a source detected at TeV energies (28 sources) or (2) an object that has been studied with TeV instruments and for which an upper limit has been reported (68 objects). The Fermi observations show clear detections of 38 of these TeV-selected objects, of which 21 are joint GeV-TeV sources, and 29 were not in the thirdmore » EGRET catalog. For each of the 38 Fermi-detected sources, spectra and light curves are presented. Most can be described with a power law of spectral index harder than 2.0, with a spectral break generally required to accommodate the TeV measurements. Based on an extrapolation of the Fermi spectrum, we identify sources, not previously detected at TeV energies, which are promising targets for TeV instruments. Finally, evidence for systematic evolution of the γ-ray spectrum with redshift is presented and discussed in the context of interaction with the extragalactic background light.« less

Embolic Strokes of Unknown Source and Cryptogenic Stroke: Implications in Clinical Practice

PubMed Central

Nouh, Amre; Hussain, Mohammed; Mehta, Tapan; Yaghi, Shadi

2016-01-01

Up to a third of strokes are rendered cryptogenic or of undetermined etiology. This number is specifically higher in younger patients. At times, inadequate diagnostic workups, multiple causes, or an under-recognized etiology contributes to this statistic. Embolic stroke of undetermined source, a new clinical entity particularly refers to patients with embolic stroke for whom the etiology of embolism remains unidentified despite through investigations ruling out established cardiac and vascular sources. In this article, we review current classification and discuss important clinical considerations in these patients; highlighting cardiac arrhythmias and structural abnormalities, patent foramen ovale, paradoxical sources, and potentially under-recognized, vascular, inflammatory, autoimmune, and hematologic sources in relation to clinical practice. PMID:27047443

Swift follow-up of 1RXS J194211.9+255552

NASA Astrophysics Data System (ADS)

Sidoli, L.; Fiocchi, M.; Bird, A. J.; Drave, S. P.; Bazzano, A.; Persi, P.; Tarana, A.; Sguera, V.; Chenevez, J.; Kuulkers, E.

2011-12-01

Following the INTEGRAL/JEM-X detection of the unidentified source 1RXS J194211.9+255552 (ATel #3816) on December 18, we asked for a Swift/XRT follow-up observation. Swift observed the source field on December 21, 2011 at 06:10:09.7 (UTC), with a net exposure of 1756 s. Within the ROSAT error circle there is only one pointlike source, at the following position (J2000): RA(hh mm ss.s) = 19h42m11.13s, Dec(dd mm ss.s) = +25:56:07.32 (3.6 arcsec error radius).

Optical identification of IGR J18308-1232 as a Cataclysmic Variable

NASA Astrophysics Data System (ADS)

Parisi, P.; Masetti, N.; Jimenez, E.; Chavushyan, V.; Bassani, L.; Bazzano, A.; Bird, A. J.

2008-09-01

We report on a spectroscopic analysis of optical sources inside the error circle of the XMM-Newton slew source XMMLS1 J183049.6-123218 (see Ibarra et al., ATel #1527), associated with the unidentified INTEGRAL source IGR J18308-1232 (Bird et al. 2007, ApJS, 170, 175). The observations were performed on 2008 June 28, starting at 06:37 UT, with the Boller & Chivens spectrograph mounted on the 2.1m telescope of the Observatorio Astronomico Nacional (San Pedro Martir, Baja California, Mexico), for a total exposure time of 7200 s.

The multiple infrared source GL 437

NASA Technical Reports Server (NTRS)

Wynn-Williams, C. G.; Becklin, E. E.; Beichman, C. A.; Capps, R.; Shakeshaft, J. R.

1981-01-01

Infrared and radio continuum observations of the multiple infrared source GL 437 show that it consists of a compact H II region plus two objects which are probably early B stars undergoing rapid mass loss. The group of sources appears to be a multiple system of young stars that have recently emerged from the near side of a molecular cloud. Emission in the unidentified 3.3 micron feature is associated with, but more extended than, the emission from the compact H II region; it probably arises from hot dust grains at the interface between the H II region and the molecular cloud.

Whole Genome Shotgun Analysis: the Resolving Power to Distinguish 2009 and 2010 Clinical Isolates of Salmonella Typhimurium Possessing the Same PFGE Type

USDA-ARS?s Scientific Manuscript database

Between 2009 and 2011, Salmonella enterica subsp. enterica serovar Typhimurium with the JPXX01.0014 pulse field gel electrophoresis (PFGE) type was isolated across the United States. The 2009 isolates were associated with an outbreak from an unidentified food source, while later isolates were linked...

Plasma in a Pulsed Discharge Environment

NASA Technical Reports Server (NTRS)

Remy, J.; Bienier, L.; Salama, F.

2005-01-01

The plasma generated in a pulsed slit discharge nozzle is used to form molecular ions in an astrophysically relevant environment. The plasma has been characterized as a glow discharge in the abnormal regime. Laboratory studies help understand the formation processes of polycyclic aromatic hydrocarbon (PAH) ions that are thought to be the source of the ubiquitous unidentified infrared bands.

Dental DNA fingerprinting in identification of human remains

PubMed Central

Girish, KL; Rahman, Farzan S; Tippu, Shoaib R

2010-01-01

The recent advances in molecular biology have revolutionized all aspects of dentistry. DNA, the language of life yields information beyond our imagination, both in health or disease. DNA fingerprinting is a tool used to unravel all the mysteries associated with the oral cavity and its manifestations during diseased conditions. It is being increasingly used in analyzing various scenarios related to forensic science. The technical advances in molecular biology have propelled the analysis of the DNA into routine usage in crime laboratories for rapid and early diagnosis. DNA is an excellent means for identification of unidentified human remains. As dental pulp is surrounded by dentin and enamel, which forms dental armor, it offers the best source of DNA for reliable genetic type in forensic science. This paper summarizes the recent literature on use of this technique in identification of unidentified human remains. PMID:21731342

Organochlorine contaminants in cormorant, darter, egret, and ibis eggs from South Africa.

PubMed

Bouwman, Henk; Polder, Anuschka; Venter, Belinda; Skaare, Janneche U

2008-03-01

During the last 15 years, no research has been published on the levels of pesticides in bird eggs from South Africa, despite the high levels found previously. We analysed eggs from African darter, cattle egret, reed cormorant, African sacred ibis, as well as single eggs from some other species, and found HCB, DDTs, HCHs, chlordanes and PCBs at detectable levels. The presence of mirex in all species was unexpected, since this compound was never registered in South Africa. It also seemed as if terrestrial feeding birds had higher DDE:PCB ratios when compared with aquatic feeding birds. Except for chlordane, the African darter eggs had the highest levels of all other compounds (mean 370 and 300 ng g(-1) ww Sigma pesticides and Sigma PCBs, respectively). Multivariate analysis clearly distinguished the aquatic and terrestrially feeding birds on pollution profile. The African darter (aquatic feeding) and the cattle egret (terrestrial feeding) would be good indicator candidates. Eggshell thinning was detected in the African darter, and was associated with most of the compounds, including DDE and PCBs. We raise a concern that generally longer living birds in warmer climates, laying fewer eggs per clutch, might be at increased risk when compared with trophically similar birds exposed to equivalent levels of pollution in colder climates. Given the scarcity of water and the high biodiversity in Southern Africa, climate change will exert strong pressure, and any additional anthropogenic contamination at levels that can cause subtle behavioural, developmental and reproductive changes, can have serious effects.

Detection of a long-duration solar gamma-ray flare on Jun. 11, 1991 with EGRET on Compton-GRO

NASA Technical Reports Server (NTRS)

Kanbach, G.; Bertsch, D. L.; Fitchel, C. E.; Hartman, R. C.; Hunter, S. D.; Kniffen, D. A.; Kwok, P. W.; Lin, Y. C.; Mattox, J. R.; Mayer-Hasslewander, H. A.

1992-01-01

On 11 Jun. 1991, the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory (Comption-GRO) observed high energy gamma radiation above 30 MeV from the Sun following an intense flare around 2:00 Universal Time (UT). After the decay of most of the x ray flare, which caused nearly complete deadtime losses in EGRET, high energy emission was registered during the interval from about 3:30 UT to at least 10:30 UT. Gamma rays were detected up to energies above 1 GeV. The solar origin of the emission is assured by the time profile of the gamma ray count rate and by time resolved sky maps, which show a clear maximum at the position of the sun. The gamma ray lightcurve of the flare can be described with two components: a fast decaying emission with an e-folding time constant of about 25 minutes and a slow decay with about 255 minutes. There are indications for a spectral evolution with time, such that the emission below 100 MeV fades away earlier than the 100 to 300 MeV radiation, roughly in the time scale of the fast component. The spectrum of the flare can be fitted with a composite of a proton generated pion neutral spectrum and an electron bremsstrahlung component. The latter can be identified with the fast decaying component of the lightcurve.

MULTIBAND DIAGNOSTICS OF UNIDENTIFIED 1FGL SOURCES WITH SUZAKU AND SWIFT X-RAY OBSERVATIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takeuchi, Y.; Kataoka, J.; Maeda, K.

2013-10-01

We have analyzed all the archival X-ray data of 134 unidentified (unID) gamma-ray sources listed in the first Fermi/LAT (1FGL) catalog and subsequently followed up by the Swift/XRT. We constructed the spectral energy distributions (SEDs) from radio to gamma-rays for each X-ray source detected, and tried to pick up unique objects that display anomalous spectral signatures. In these analyses, we target all the 1FGL unID sources, using updated data from the second Fermi/LAT (2FGL) catalog on the Large Area Telescope (LAT) position and spectra. We found several potentially interesting objects, particularly three sources, 1FGL J0022.2–1850, 1FGL J0038.0+1236, and 1FGL J0157.0–5259,more » which were then more deeply observed with Suzaku as a part of an AO-7 program in 2012. We successfully detected an X-ray counterpart for each source whose X-ray spectra were well fitted by a single power-law function. The positional coincidence with a bright radio counterpart (currently identified as an active galactic nucleus, AGN) in the 2FGL error circles suggests these sources are definitely the X-ray emission from the same AGN, but their SEDs show a wide variety of behavior. In particular, the SED of 1FGL J0038.0+1236 is not easily explained by conventional emission models of blazars. The source 1FGL J0022.2–1850 may be in a transition state between a low-frequency peaked and a high-frequency peaked BL Lac object, and 1FGL J0157.0–5259 could be a rare kind of extreme blazar. We discuss the possible nature of these three sources observed with Suzaku, together with the X-ray identification results and SEDs of all 134 sources observed with the Swift/XRT.« less

PSR J1906+0722: an Elusive Gamma-Ray Pulsar

DOE PAGES

Clark, C. J.; Pletsch, H. J.; Wu, J.; ...

2015-08-04

Here, we report the discovery of PSR J1906+0722, a gamma-ray pulsar detected as part of a blind survey of unidentified Fermi Large Area Telescope (LAT) sources being carried out on the volunteer distributed computing system, Einstein@Home. This newly discovered pulsar previously appeared as the most significant remaining unidentified gamma-ray source without a known association in the second Fermi-LAT source catalog (2FGL) and was among the top 10 most significant unassociated sources in the recent third catalog (3FGL). PSR J1906+0722 is a young, energetic, isolated pulsar, with a spin frequency of 8.9 Hz, a characteristic age of 49 kyr, and spin-down powermore » $$1.0\\times {10}^{36}$$ erg s -1. In 2009 August it suffered one of the largest glitches detected from a gamma-ray pulsar ($${\\rm{\\Delta }}f/f\\approx 4.5\\times {10}^{-6}$$). Remaining undetected in dedicated radio follow-up observations, the pulsar is likely radio-quiet. An off-pulse analysis of the gamma-ray flux from the location of PSR J1906+0722 revealed the presence of an additional nearby source, which may be emission from the interaction between a neighboring supernova remnant and a molecular cloud. We discuss possible effects which may have hindered the detection of PSR J1906+0722 in previous searches and describe the methods by which these effects were mitigated in this survey. Lastly, we also demonstrate the use of advanced timing methods for estimating the positional, spin and glitch parameters of difficult-to-time pulsars such as this.« less

PSR J1906+0722: An Elusive Gamma-Ray Pulsar

NASA Astrophysics Data System (ADS)

Clark, C. J.; Pletsch, H. J.; Wu, J.; Guillemot, L.; Ackermann, M.; Allen, B.; de Angelis, A.; Aulbert, C.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Bock, O.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caragiulo, M.; Caraveo, P. A.; Cecchi, C.; Champion, D. J.; Charles, E.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Cuéllar, A.; Cutini, S.; D'Ammando, F.; Desiante, R.; Drell, P. S.; Eggenstein, H. B.; Favuzzi, C.; Fehrmann, H.; Ferrara, E. C.; Focke, W. B.; Franckowiak, A.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giordano, F.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grove, J. E.; Guiriec, S.; Harding, A. K.; Hays, E.; Hewitt, J. W.; Hill, A. B.; Horan, D.; Hou, X.; Jogler, T.; Johnson, A. S.; Jóhannesson, G.; Kramer, M.; Krauss, F.; Kuss, M.; Laffon, H.; Larsson, S.; Latronico, L.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Machenschalk, B.; Manfreda, A.; Marelli, M.; Mayer, M.; Mazziotta, M. N.; Michelson, P. F.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nuss, E.; Ohsugi, T.; Orienti, M.; Orlando, E.; de Palma, F.; Paneque, D.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Saz Parkinson, P. M.; Schaal, M.; Schulz, A.; Sgrò, C.; Siskind, E. J.; Spada, F.; Spandre, G.; Spinelli, P.; Suson, D. J.; Takahashi, H.; Thayer, J. B.; Tibaldo, L.; Torne, P.; Torres, D. F.; Tosti, G.; Troja, E.; Vianello, G.; Wood, K. S.; Wood, M.; Yassine, M.

2015-08-01

We report the discovery of PSR J1906+0722, a gamma-ray pulsar detected as part of a blind survey of unidentified Fermi Large Area Telescope (LAT) sources being carried out on the volunteer distributed computing system, Einstein@Home. This newly discovered pulsar previously appeared as the most significant remaining unidentified gamma-ray source without a known association in the second Fermi-LAT source catalog (2FGL) and was among the top 10 most significant unassociated sources in the recent third catalog (3FGL). PSR J1906+0722 is a young, energetic, isolated pulsar, with a spin frequency of 8.9 Hz, a characteristic age of 49 kyr, and spin-down power 1.0× {10}36 erg s-1. In 2009 August it suffered one of the largest glitches detected from a gamma-ray pulsar ({{Δ }}f/f≈ 4.5× {10}-6). Remaining undetected in dedicated radio follow-up observations, the pulsar is likely radio-quiet. An off-pulse analysis of the gamma-ray flux from the location of PSR J1906+0722 revealed the presence of an additional nearby source, which may be emission from the interaction between a neighboring supernova remnant and a molecular cloud. We discuss possible effects which may have hindered the detection of PSR J1906+0722 in previous searches and describe the methods by which these effects were mitigated in this survey. We also demonstrate the use of advanced timing methods for estimating the positional, spin and glitch parameters of difficult-to-time pulsars such as this.

A Family Clustered Nitrite Intoxication Investigation in Gaoxin District, Suzhou, China, 2013.

PubMed

Wang, Ruiping; Teng, Chengang; Zhang, Ning; Zhang, Jun; Conway, George

2013-12-01

In April, 2013, a Suzhou Hospital reported a nitrite intoxication patient in coma as well as 2 family members with the similar symptom 5 days ahead. We investigated the event to identify the cause, source and possible pollution ways of the contamination. We defined case as any person living in YSHY community who has cyanosis and with at least one of the following symptoms: dizziness, headache, fatigue, tachycardia, drowsiness, nausea, vomiting, abdominal pain or diar-rhea during April 15 to April 25, 2013. We searched for case by interviewing community residents and reviewing clinics' medical records; information was then retrospectively collected on the patient's food history, cooking procedures and food sources. We identified 3 nitrite intoxication cases, 1 male and 2 female from a family. The interval time between dinner and onset was < 1 hour. Retrospective survey showed 'sugar stir and mix asparagus' on April 17 and 'scrambled asparagus' on April 21 were suspected foods. Both suspected dishes had 'sugar' added, sourced from a clean-up of a neighboring rental house. Nitrite was detected in a vomitus sample, the 'sugar' and two leftover food samples. This family clustered nitrite intoxication was induced by using unidentified nitrite as sugar to cook dishes. We recommend sodium nitrite should be dyed with bright colors to avoid mistaking it for plain salt or sugar, health departments strengthen food hygiene propaganda to improve people's recognition of food safety, and to alert them the dangerous of eating unidentified or unknown source food.

Oxidant-induced damage to equine erythrocytes from exposure to Pistacia atlantica, Pistacia terebinthus, and Pistacia chinensis.

PubMed

Walter, Kyla M; Moore, Caroline E; Bozorgmanesh, Rana; Magdesian, K Gary; Woods, Leslie W; Puschner, Birgit

2014-11-01

Two horses were referred for methemoglobinemia and hemolytic anemia following 5 acute deaths in their herd from an unidentified toxin source. Horses have a greater risk than other mammalian species of developing methemoglobinemia and hemolytic anemia following ingestion of oxidizing toxins, due to deficiencies in the mechanisms that protect against oxidative damage in erythrocytes. Their susceptibility to oxidative erythrocyte damage is evident in the numerous cases of red maple (Acer rubrum) toxicosis. The suspected toxins causing A. rubrum toxicosis are tannic acid, gallic acid, and a metabolite of gallic acid, pyrogallol. These compounds can be found in a variety of plants, posing a risk to equine health. In order to quickly identify toxin sources, 2 rapid in vitro assays were developed to screen plant extracts for the ability to induce methemoglobin formation or cause hemolysis in healthy equine donor erythrocytes. The plant extract screening focused on 3 species of the genus Pistacia: P. atlantica, P. terebinthus, and P. chinensis, which were located in the horse pasture. Extracts of the seeds and leaves of each species induced methemoglobin formation and resulted in hemolysis, with seed extracts having greater potency. The in vitro assays used in the current study provide a useful diagnostic method for the rapid identification of oxidizing agents from unidentified sources. There is no effective treatment for oxidative erythrocyte damage in horses, making rapid identification and removal of the source essential for the prevention of poisoning. © 2014 The Author(s).

Oxidant-induced damage to equine erythrocytes from exposure to Pistacia atlantica, Pistacia terebinthus, and Pistacia chinensis

PubMed Central

Walter, Kyla M.; Moore, Caroline E.; Bozorgmanesh, Rana; Magdesian, K. Gary; Woods, Leslie W.; Puschner, Birgit

2017-01-01

Two horses were referred for methemoglobinemia and hemolytic anemia following 5 acute deaths in their herd from an unidentified toxin source. Horses have a greater risk than other mammalian species of developing methemoglobinemia and hemolytic anemia following ingestion of oxidizing toxins, due to deficiencies in the mechanisms that protect against oxidative damage in erythrocytes. Their susceptibility to oxidative erythrocyte damage is evident in the numerous cases of red maple (Acer rubrum) toxicosis. The suspected toxins causing A. rubrum toxicosis are tannic acid, gallic acid, and a metabolite of gallic acid, pyrogallol. These compounds can be found in a variety of plants, posing a risk to equine health. In order to quickly identify toxin sources, 2 rapid in vitro assays were developed to screen plant extracts for the ability to induce methemoglobin formation or cause hemolysis in healthy equine donor erythrocytes. The plant extract screening focused on 3 species of the genus Pistacia: P. atlantica, P. terebinthus, and P. chinensis, which were located in the horse pasture. Extracts of the seeds and leaves of each species induced methemoglobin formation and resulted in hemolysis, with seed extracts having greater potency. The in vitro assays used in the current study provide a useful diagnostic method for the rapid identification of oxidizing agents from unidentified sources. There is no effective treatment for oxidative erythrocyte damage in horses, making rapid identification and removal of the source essential for the prevention of poisoning. PMID:25227420

Recent Results on SNRs and PWNe from the Fermi Large Area Telescope

NASA Technical Reports Server (NTRS)

Hays, Elizabeth A.

2010-01-01

Topics include: Fermi LAT Collaboration groups; galactic results from LAT; a GeV, wide-field instrument; the 1FGL catalog, the Fermi LAT 1FGL source catalog, unidentified gamma-ray sources; variability in 1FGL sources; curvature in 1FGL sources; spectral-variability classification; gamma-ray pulsars and MSPs; GeV PWN - where to look; Crab pulsar and nebula; Vela X nebular of Vela pulsar; MSH 15-52; GeV PWNe spectra; GeV nebula limits; Nebula search of LAT pulsars; supernova remnants; SNR: GeV morphology; SNR: molecular connection; SNR: GeV breaks; SNR: young vs. old. The summary includes slides about the Large Area Telescope (LAT) and LAT sensitivity with time.

The bright unidentified γ-ray source 1FGL J1227.9–4852: Can it be associated with a low-mass X-ray binary? [The bright unidentified γ-ray source 1FGL J1227.9–4852: Can it be associated with an LMXB?

DOE PAGES

Hill, A. B.; Szostek, A.; Corbel, S.; ...

2011-07-08

We present an analysis of high energy (HE; 0.1–300 GeV) γ-ray observations of 1FGL J1227.9–4852 with the Fermi Gamma-ray Space Telescope, follow-up radio observations with the Australia Telescope Compact Array, Giant Metrewave Radio Telescope and Parkes radio telescopes of the same field and follow-up optical observations with the ESO VLT. We also examine archival XMM– Newton and INTEGRAL X-ray observations of the region around this source. The γ-ray spectrum of 1FGL J1227.9–4852 is best fitted with an exponentially cut-off power law, reminiscent of the population of pulsars observed by Fermi. A previously unknown, compact radio source within the 99.7 permore » cent error circle of 1FGL J1227.9–4852 is discovered and has a morphology consistent either with an AGN core/jet structure or with two roughly symmetric lobes of a distant radio galaxy. A single bright X-ray source XSS J12270–4859, a low-mass X-ray binary, also lies within the 1FGL J1227.9–4852 error circle and we report the first detection of radio emission from this source. The potential association of 1FGL J1227.9–4852 with each of these counterparts is discussed. Based upon the available data we find the association of the γ-ray source to the compact double radio source unlikely and suggest that XSS J12270–4859 is a more likely counterpart to the new HE source. As a result, we propose that XSS J12270–4859 may be a millisecond binary pulsar and draw comparisons with PSR J1023+0038.« less

Currency notes and coins as a possible source of transmitting fungal pathogens of man and plants.

PubMed

Wanule, Dinesh; Jalander, Vaghmare; Gachande, B D; Sirsikar, A N

2011-10-01

Currency (notes and coins) handling by people during transaction is one of the most mobile objects within the community, which has a potential of transmitting pathogens. A survey carried out recently in Nanded city (Maharashtra) revealed heavy contamination of currency notes and coins by important fungal pathogens of plants and man, i.e. Aspergillus niger (60.37%), A. flavus (3.98%), A.nidulans (0.2%), Penicillium citrinum (17.80%), Alternaria tenuis (0.20%), Curvularia pallescens (0.20%), Cladosporium cladosporioides (10.69%), Rhizopus stolonifer (1.04%), an unidentified Aspergillus species .1 (0.20%) and another unidentified Aspergillus species.2 (3.14%), Fusarium sp. (0.20%), Trichoderma viride (0.20%),white sterile mycelium (0.62%) and brown sterile mycelium (0.62%). The study highlights the importance of preventing and controlling fungal contamination of currency notes and coins in public health and plant protection. Currency notes or coins are rarely suspected as infection sources and often not quarantined at airport or seaport terminal. Possible transmission of pathogens or "alien", invasive species through currency across borders or across countries needs to be taken into consideration especially under circumstances of serious outbreak of important disease or when there is a threat of biological warfare.

The EGRET high energy gamma ray telescope

NASA Technical Reports Server (NTRS)

Hartman, R. C.; Bertsch, D. L.; Fichtel, C. E.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Kwok, P. W.; Lin, Y. C.; Mattox, J. R.; Mayer-Hasselwander, H. A.

1992-01-01

The Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory (GRO) is sensitive in the energy range from about 20 MeV to about 30,000 MeV. Electron-positron pair production by incident gamma photons is utilized as the detection mechanism. The pair production occurs in tantalum foils interleaved with the layers of a digital spark chamber system; the spark chamber records the tracks of the electron and positron, allowing the reconstruction of the arrival direction of the gamma ray. If there is no signal from the charged particle anticoincidence detector which surrounds the upper part of the detector, the spark chamber array is triggered by two hodoscopes of plastic scintillators. A time of flight requirement is included to reject events moving backward through the telescope. The energy of the gamma ray is primarily determined by absorption of the energies of the electron and positron in a 20 cm deep NaI(Tl) scintillator.

The EGRET high energy gamma ray telescope

NASA Astrophysics Data System (ADS)

Hartman, R. C.; Bertsch, D. L.; Fichtel, C. E.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Kwok, P. W.; Lin, Y. C.; Mattox, J. R.; Mayer-Hasselwander, H. A.; Michelson, P. F.; von Montigny, C.; Nolan, P. L.; Pinkau, K.; Rothermel, H.; Schneid, E.; Sommer, M.; Sreekumar, P.; Thompson, D. J.

1992-02-01

The Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory (GRO) is sensitive in the energy range from about 20 MeV to about 30,000 MeV. Electron-positron pair production by incident gamma photons is utilized as the detection mechanism. The pair production occurs in tantalum foils interleaved with the layers of a digital spark chamber system; the spark chamber records the tracks of the electron and positron, allowing the reconstruction of the arrival direction of the gamma ray. If there is no signal from the charged particle anticoincidence detector which surrounds the upper part of the detector, the spark chamber array is triggered by two hodoscopes of plastic scintillators. A time of flight requirement is included to reject events moving backward through the telescope. The energy of the gamma ray is primarily determined by absorption of the energies of the electron and positron in a 20 cm deep NaI(Tl) scintillator.

KSC-99pp0248

NASA Image and Video Library

1999-02-26

KENNEDY SPACE CENTER, FLA. -- White pelicans are joined by a few egrets at a feeding frenzy in the waters of the Merritt Island National Wildlife Refuge, which shares a boundary with Kennedy Space Center. Pelicans in flight display their black wing tips, which are hidden when folded. The habitat of white pelicans are marshy lakes along the Pacific and Texas coasts, wintering chiefly in coastal lagoons such as this one. They often capture fish cooperatively, forming a long line, beating their wings and driving the prey into shallow water. The 92,000-acre refuge is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds

KENNEDY SPACE CENTER, FLA. - A great white heron silently waits in the tall grass within KSC. The heron is one of 310 species of birds that inhabit the National Merritt Island Wildlife Refuge, which shares a boundary with KSC. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

NASA Image and Video Library

2003-10-24

KENNEDY SPACE CENTER, FLA. - A great white heron silently waits in the tall grass within KSC. The heron is one of 310 species of birds that inhabit the National Merritt Island Wildlife Refuge, which shares a boundary with KSC. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

KENNEDY SPACE CENTER, FLA. - A Great Blue Heron takes flight from waters on KSC. It is one of 310 species of birds that inhabit the National Merritt Island Wildlife Refuge, which shares a boundary with KSC. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

NASA Image and Video Library

2003-07-29

KENNEDY SPACE CENTER, FLA. - A Great Blue Heron takes flight from waters on KSC. It is one of 310 species of birds that inhabit the National Merritt Island Wildlife Refuge, which shares a boundary with KSC. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

Observation of high-energy gamma rays from the quasi-stellar object CTA 102

NASA Technical Reports Server (NTRS)

Nolan, P. L.; Bertsch, D. L.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Lin, Y. C.; Mattox, J. R.; Mayer-Hasselwander, H. A.

1993-01-01

The quasar CTA 102 (QSO 2230 + 114) was observed four times in 1991-1992 by the EGRET high-energy gamma-ray telescope on the Compton GRO satellite. In the 1992 January 23-February 6 observation, emission was detected at the level (2.4 +/- 0.5) x 10 exp 7 photons/sq cm s (E is greater than 100 MeV). The other observations produced upper limits or detections with lower significance which are consistent with the same flux. The photon spectrum can be represented by a power law with a number index of 2.6 +/- 0.2, the softest so far observed by EGRET. The emitted gamma-ray luminosity, if isotropic, is 5 x 10 exp 47 ergs/s (H(0) = 75 km/s Mpc , q(0) = 0.5), although there are good reasons to believe that the gamma emission is strongly beamed.

A study of the sensitivity of an imaging telescope (GRITS) for high energy gamma-ray astronomy

NASA Technical Reports Server (NTRS)

Yearian, Mason R.

1990-01-01

When a gamma-ray telescope is placed in Earth orbit, it is bombarded by a flux of cosmic protons much greater than the flux of interesting gammas. These protons can interact in the telescope's thermal shielding to produce detectable gamma rays, most of which are vetoed. Since the proton flux is so high, the unvetoed gamma rays constitute a significant background relative to some weak sources. This background increases the observing time required to pinpoint some sources and entirely obscures other sources. Although recent telescopes have been designed to minimize this background, its strength and spectral characteristics were not previously calculated in detail. Monte Carlo calculations are presented which characterize the strength, spectrum and other features of the cosmic proton background using FLUKA, a hadronic cascade program. Several gamma-ray telescopes, including SAS-2, EGRET and the Gamma Ray Imaging Telescope System (GRITS), are analyzed, and their proton-induced backgrounds are characterized. In all cases, the backgrounds are either shown to be low relative to interesting signals or suggestions are made which would reduce the background sufficiently to leave the telescope unimpaired. In addition, several limiting cases are examined for comparison to previous estimates and calibration measurements.

[Characteristics of natural strains of naphthalene-utilizing bacteria of the genus Pseudomonas].

PubMed

Levchuk, A A; Vasilenko, S L; Bulyga, I M; Titok, M A; Thomas, K M

2005-01-01

Sixty-three strains of bacteria capable of utilizing naphthalene as the sole source of carbon and energy were isolated from 137 samples of soil taken in different sites in Belarus. All isolated bacteria contained extrachromosomal genetic elements of 45 to 150 kb in length. It was found that bacteria of 31 strains contained the IncP-9 incompatibility group plasmids, bacteria of one strain carried a plasmid containing replicons IncP-9 and IncP-7, and bacteria of 31 strains contained unidentified plasmids. Primary identification showed that the hosts of plasmids of naphthalene biodegradation are fluorescent bacteria of the genus Pseudomonas (P. putida and P. aeruginosa; a total of 47 strains) and unidentified nonfluorescent microorganisms (a total of 16 strains). In addition to the ability to utilize naphthalene, some strains exhibited the ability to stimulate the growth and development of the root system of Secale cereale.

ISO Spectroscopy of Proto-Planetary Nebulae

NASA Technical Reports Server (NTRS)

Hrivnak, Bruce J.

2000-01-01

The goal of this program was to determine the chemical properties of the dust shells around protoplanetary nebulae (PPNs) through a study of their short-wavelength (6-45 micron) infrared spectra. PPNs are evolved stars in transition from the asymptotic giant branch to the planetary nebula stages. Spectral features in the 10 to 20 gm region indicate the chemical nature (oxygen- or carbon-rich), and the strengths of the features relate to the physical properties of the shells. A few bright carbon-rich PPNs have been observed to show PAH features and an unidentified 21 micron emission feature. We used the Infrared Space Observatory (ISO) to observe a sample of IRAS sources that have the expected properties of PPNs and for which we have accurate positions. Some of these have optical counterparts (proposal SWSPPN01) and some do not (SWSPPN02). We had previously observed these from the ground with near-infrared photometry and, for those with visible counterparts, visible photometry and spectroscopy, which we have combined with these new ISO data in the interpretation of the spectra. We have completed a study of the unidentified emission feature at 21 micron in eight sources. We find the shape of the feature to be the same in all of the sources, with no evidence of any substructure. The ratio of the emission peak to continuum ranges from 0.13 to 1.30. We have completed a study of seven PPNs and two other carbon-rich objects for which we had obtained ISO 2-45 micron observations. The unidentified emission features at 21 and 30 micron were detected in six sources, including four new detections of the 30 micron feature. This previously unresolved 30 micron feature was resolved and found to consist of a broad feature peaking at 27.2 micron (the "30 micron" feature) and a narrower feature peaking at 25.5 micron (the "26 micron" feature). This new 26 micron feature is detected in eight sources and is particularly strong in IRAS Z02229+6208 and 16594-4656. The unidentified features at 3.3, 6,2, 7.7, and 11.3 micron, which are commonly observed in planetary nebulae and HII regions, are also seen in these PPNs. However, their strengths relative to the continuum plateaus at 8 and 12 micron are weaker than in planetary nebulae. The 6.9 micron feature, seen almost exclusively in PPNs, is strong. The spectral energy distributions of these PPNs were fitted with a radiative-transfer model, taking into account the emission features at 21, 26, and 30 micron. A significant fraction of the total energy output is emitted in these features: as high as 20% in the 30 micron feature and 8% in the 21 micron feature. The fact that so much energy is carried in these features suggests that the material responsible for this feature must be made of abundant elements, and most likely involves carbon. The change in the in feature strengths from stronger aliphatic bonds in PPNs to stronger aromatic bonds in PNs suggests a chemical and physical evolution in the carbonaceous circumstellar dust during this transition time scale of a few thousand years.

Fermi Gamma-Ray Space Telescope: Science Highlights for the First 8 Months

NASA Technical Reports Server (NTRS)

Moiseev, Alexander

2010-01-01

The Fermi Gamma-ray Space Telescope was launched on June 11, 2008 and since August 2008 has successfully been conducting routine science observations of high energy phenomena in the gamma-ray sky. A number of exciting discoveries have been made during its first year of operation, including blazar flares, high-energy gamma-ray bursts, and numerous new,gamma-ray sources of different types, among them pulsars and Active Galactic Nuclei (AGN). fermi-LAT also performed accurate mea.<;urement of the diffuse gamma-radiation which clarifies the Ge V excess reported by EGRET almost 10 years ago, high precision measurement of the high energy electron spectrum, and other observations. An overview of the observatory status and recent results as of April 30, 2009, are presented. Key words: gamma-ray astronomy, cosmic rays, gamma-ray burst, pulsar, blazar. diffuse gamma-radiation

Seasonal distribution of bird populations at the Patuxent Research Refuge

USGS Publications Warehouse

Hoffman, D.J.; Henny, C.J.; Hill, E.F.; Keith, J.A.; Grove, R.A.

2000-01-01

High concentrations of mercury from past mining activities have accumulated in the food chain of fish-eating birds nesting along the mid to lower Carson River. Activities of nine plasma and tissue enzymes, and concentrations of other plasma and tissue constituents were measured for black-crowned night-heron, Nycticorax nycticorax, (BCNH) and snowy egret, Egretta thula, (SE) nestlings from two high mercury sites and one low mercury site. Geometric mean blood Hg concentrations for BCNHs at the high mercury sites were 2.6 and 2.8 ppm (ww) and 0.6 ppm at the low mercury site. Blood concentrations for SEs were 3.6 and 1.9 ppm at the high mercury sites and 0.7 ppm at the low mercury site. In BCNHs plasma glutathione peroxidase (GSH peroxidase) activity was lower in both high mercury sites relative to the low mercury site. Butyryl cholinesterase (BuChe), ALT, glutathione reductase (GSSG-reductase) and LDH-L activities were lower in one high mercury site. In SEs significant differences were lower BuChe and LDH-L, but elevated GGT activities. Evidence of renal stress in both species at high mercury sites included increased plasma uric acid, blood urea nitrogen, and creatinine concentrations as well as oxidative stress in the kidney tissue itself where oxidized glutathione increased. A number of the mercury site-related effects, including decreased plasma GSH-peroxidase and hepatic G-6-PDH activities, higher GSSG-reductase activity, and lower hepatic concentrations of reduced thiols have been reported in methylmercury feeding studies with great egrets and mallards. These findings suggest the utility of herons and egrets for monitoring mercury sites.

RXTE All-Sky Slew Survey. Catalog of X-Ray Sources at B Greater Than 10 deg

NASA Technical Reports Server (NTRS)

Revnivtsev, M.; Sazonov, S.; Jahoda, K.; Gilfanov, M.

2004-01-01

We report results of a serendipitous hard X-ray (3-20 keV), nearly all-sky (absolute value of b greater than l0 deg.) survey based on RXTE/PCA observations performed during satellite reorientations in 1996-2002. The survey is 80% (90%) complete to a 4(sigma) limiting flux of approx. = 1.8 (2.5) x 10(exp -l1) erg/s sq cm in the 3-20 keV band. The achieved sensitivity in the 3-8 keV and 8-20 keV subbands is similar to and an order of magnitude higher than that of the previously record HEAO-1 A1 and HEAO-1 A4 all-sky surveys, respectively. A combined 7 x 10(exp 3) sq. deg area of the sky is sampled to flux levels below l0(exp -11) erg/ s sq cm (3-20 keV). In total 294 sources are detected and localized to better than 1 deg. 236 (80%) of these can be confidently associated with a known astrophysical object; another 22 likely result from the superposition of 2 or 3 closely located known sources. 35 detected sources remain unidentified, although for 12 of these we report a likely soft X-ray counterpart from the ROSAT all-sky survey bright source catalog. Of the reliably identified sources, 63 have local origin (Milky Way, LMC or SMC), 64 are clusters of galaxies and 100 are active galactic nuclei (AGN). The fact that the unidentified X-ray sources have hard spectra suggests that the majority of them are AGN, including highly obscured ones (N(sub H) greater than l0(exp 23)/sq cm). For the first time we present a log N-log S diagram for extragalactic sources above 4 x l0(exp -12) erg/ s sq cm at 8-20 keV. Key words. cosmo1ogy:observations - diffuse radiation - X-rays general

Deep view of the Large Magellanic Cloud with six years of Fermi-LAT observations

NASA Astrophysics Data System (ADS)

Ackermann, M.; Albert, A.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Bloom, E. D.; Bonino, R.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Caliandro, G. A.; Cameron, R. A.; Caragiulo, M.; Caraveo, P. A.; Cavazzuti, E.; Cecchi, C.; Charles, E.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Cohen-Tanugi, J.; Cutini, S.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Desiante, R.; Digel, S. W.; Drell, P. S.; Favuzzi, C.; Ferrara, E. C.; Focke, W. B.; Franckowiak, A.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giordano, F.; Godfrey, G.; Grenier, I. A.; Grondin, M.-H.; Guillemot, L.; Guiriec, S.; Harding, A. K.; Hill, A. B.; Horan, D.; Jóhannesson, G.; Knödlseder, J.; Kuss, M.; Larsson, S.; Latronico, L.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lubrano, P.; Maldera, S.; Martin, P.; Mayer, M.; Mazziotta, M. N.; Michelson, P. F.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Murgia, S.; Nuss, E.; Ohsugi, T.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Romani, R. W.; Sánchez-Conde, M.; Schulz, A.; Sgrò, C.; Siskind, E. J.; Smith, D. A.; Spada, F.; Spandre, G.; Spinelli, P.; Suson, D. J.; Takahashi, H.; Thayer, J. B.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Troja, E.; Vianello, G.; Wood, M.; Zimmer, S.

2016-02-01

Context. The nearby Large Magellanic Cloud (LMC) provides a rare opportunity of a spatially resolved view of an external star-forming galaxy in γ-rays. The LMC was detected at 0.1-100 GeV as an extended source with CGRO/EGRET and using early observations with the Fermi-LAT. The emission was found to correlate with massive star-forming regions and to be particularly bright towards 30 Doradus. Aims: Studies of the origin and transport of cosmic rays (CRs) in the Milky Way are frequently hampered by line-of-sight confusion and poor distance determination. The LMC offers a complementary way to address these questions by revealing whether and how the γ-ray emission is connected to specific objects, populations of objects, and structures in the galaxy. Methods: We revisited the γ-ray emission from the LMC using about 73 months of Fermi-LAT P7REP data in the 0.2-100 GeV range. We developed a complete spatial and spectral model of the LMC emission, for which we tested several approaches: a simple geometrical description, template-fitting, and a physically driven model for CR-induced interstellar emission. Results: In addition to identifying PSR J0540-6919 through its pulsations, we find two hard sources positionally coincident with plerion N 157B and supernova remnant N 132D, which were also detected at TeV energies with H.E.S.S. We detect an additional soft source that is currently unidentified. Extended emission dominates the total flux from the LMC. It consists of an extended component of about the size of the galaxy and additional emission from three to four regions with degree-scale sizes. If it is interpreted as CRs interacting with interstellar gas, the large-scale emission implies a large-scale population of ~1-100 GeV CRs with a density of ~30% of the local Galactic value. On top of that, the three to four small-scale emission regions would correspond to enhancements of the CR density by factors 2 to 6 or higher, possibly more energetic and younger populations of CRs compared to the large-scale population. An alternative explanation is that this is emission from an unresolved population of at least two dozen objects, such as pulsars and their nebulae or supernova remnants. This small-scale extended emission has a spatial distribution that does not clearly correlate with known components of the LMC, except for a possible relation to cavities and supergiant shells. Conclusions: The Fermi-LAT GeV observations allowed us to detect individual sources in the LMC. Three of the newly discovered sources are associated with rare and extreme objects. The 30 Doradus region is prominent in GeV γ-rays because PSR J0540-6919 and N 157B are strong emitters. The extended emission from the galaxy has an unexpected spatial distribution, and observations at higher energies and in radio may help to clarify its origin. FITS file of Fig. 1 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/586/A71

HESS J1741-302: a hidden accelerator in the Galactic plane

NASA Astrophysics Data System (ADS)

H.E.S.S. Collaboration; Abdalla, H.; Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Angüner, E. O.; Arakawa, M.; Armand, C.; Arrieta, M.; Backes, M.; Balzer, A.; Barnard, M.; Becherini, Y.; Becker Tjus, J.; Berge, D.; Bernhard, S.; Bernlöhr, K.; Blackwell, R.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bonnefoy, S.; Bordas, P.; Bregeon, J.; Brun, F.; Brun, P.; Bryan, M.; Büchele, M.; Bulik, T.; Capasso, M.; Caroff, S.; Carosi, A.; Casanova, S.; Cerruti, M.; Chakraborty, N.; Chaves, R. C. G.; Chen, A.; Chevalier, J.; Colafrancesco, S.; Condon, B.; Conrad, J.; Davids, I. D.; Decock, J.; Deil, C.; Devin, J.; Dewilt, P.; Dirson, L.; Djannati-Ataï, A.; Donath, A.; Drury, L. O.'c.; Dyks, J.; Edwards, T.; Egberts, K.; Emery, G.; Ernenwein, J.-P.; Eschbach, S.; Farnier, C.; Fegan, S.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Funk, S.; Füßling, M.; Gabici, S.; Gallant, Y. A.; Garrigoux, T.; Gaté, F.; Giavitto, G.; Glawion, D.; Glicenstein, J. F.; Gottschall, D.; Grondin, M.-H.; Hahn, J.; Haupt, M.; Hawkes, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hinton, J. A.; Hofmann, W.; Hoischen, C.; Holch, T. L.; Holler, M.; Horns, D.; Ivascenko, A.; Iwasaki, H.; Jacholkowska, A.; Jamrozy, M.; Jankowsky, D.; Jankowsky, F.; Jingo, M.; Jouvin, L.; Jung-Richardt, I.; Kastendieck, M. A.; Katarzyński, K.; Katsuragawa, M.; Katz, U.; Kerszberg, D.; Khangulyan, D.; Khélifi, B.; King, J.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Komin, Nu.; Kosack, K.; Krakau, S.; Kraus, M.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lau, J.; Lefaucheur, J.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Leser, E.; Lohse, T.; Lorentz, M.; Liu, R.; López-Coto, R.; Lypova, I.; Malyshev, D.; Marandon, V.; Marcowith, A.; Mariaud, C.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; Meintjes, P. J.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Mohrmann, L.; Morå, K.; Moulin, E.; Murach, T.; Nakashima, S.; De Naurois, M.; Ndiyavala, H.; Niederwanger, F.; Niemiec, J.; Oakes, L.; O'Brien, P.; Odaka, H.; Ohm, S.; Ostrowski, M.; Oya, I.; Padovani, M.; Panter, M.; Parsons, R. D.; Pekeur, N. W.; Pelletier, G.; Perennes, C.; Petrucci, P.-O.; Peyaud, B.; Piel, Q.; Pita, S.; Poireau, V.; Prokhorov, D. A.; Prokoph, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Rauth, R.; Reimer, A.; Reimer, O.; Renaud, M.; De Los Reyes, R.; Rieger, F.; Rinchiuso, L.; Romoli, C.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Saito, S.; Sanchez, D. A.; Santangelo, A.; Sasaki, M.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwemmer, S.; Seglar-Arroyo, M.; Seyffert, A. S.; Shafi, N.; Shilon, I.; Shiningayamwe, K.; Simoni, R.; Sol, H.; Spanier, F.; Spir-Jacob, M.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Steppa, C.; Sushch, I.; Takahashi, T.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tibaldo, L.; Tiziani, D.; Tluczykont, M.; Trichard, C.; Tsirou, M.; Tsuji, N.; Tuffs, R.; Uchiyama, Y.; van der Walt, D. J.; van Eldik, C.; van Rensburg, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Voisin, F.; Völk, H. J.; Vuillaume, T.; Wadiasingh, Z.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Yang, R.; Zaborov, D.; Zacharias, M.; Zanin, R.; Zdziarski, A. A.; Zech, A.; Zefi, F.; Ziegler, A.; Zorn, J.; Żywucka, N.; NANTEN Collaboration; Enokiya, R.; Fukui, Y.; Hayakawa, T.; Okuda, T.; Torii, K.; Yamamoto, H.

2018-04-01

The H.E.S.S. Collaboration has discovered a new very high energy (VHE, E > 0.1 TeV) γ-ray source, HESS J1741-302, located in the Galactic plane. Despite several attempts to constrain its nature, no plausible counterpart has been found so far at X-ray and MeV/GeV γ-ray energies, and the source remains unidentified. An analysis of 145-h of observations of HESS J1741-302 at VHEs has revealed a steady and relatively weak TeV source ( 1% of the Crab Nebula flux), with a spectral index of Γ = 2.3 ± 0.2stat ± 0.2sys, extending to energies up to 10 TeV without any clear signature of a cut-off. In a hadronic scenario, such a spectrum implies an object with particle acceleration up to energies of several hundred TeV. Contrary to most H.E.S.S. unidentified sources, the angular size of HESS J1741-302 is compatible with the H.E.S.S. point spread function at VHEs, with an extension constrained to be below 0.068° at a 99% confidence level. The γ-ray emission detected by H.E.S.S. can be explained both within a hadronic scenario, due to collisions of protons with energies of hundreds of TeV with dense molecular clouds, and in a leptonic scenario, as a relic pulsar wind nebula, possibly powered by the middle-aged (20 kyr) pulsar PSR B1737-30. A binary scenario, related to the compact radio source 1LC 358.266+0.038 found to be spatially coincident with the best fit position of HESS J1741-302, is also envisaged.

HESS J1741-302: a hidden accelerator in the Galactic plane

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdalla, H.; Abramowski, A.; Aharonian, F.

The H.E.S.S. Collaboration has discovered a new very high energy (VHE, E > 0.1 TeV) γ-ray source, HESS J1741-302, located in the Galactic plane. Despite several attempts to constrain its nature, no plausible counterpart has been found so far at X-ray and MeV/GeV γ-ray energies, and the source remains unidentified. An analysis of 145-h of observations of HESS J1741-302 at VHEs has revealed a steady and relatively weak TeV source (~1% of the Crab Nebula flux), with a spectral index of Γ = 2.3 ± 0.2stat ± 0.2sys, extending to energies up to 10 TeV without any clear signature ofmore » a cut-off. In a hadronic scenario, such a spectrum implies an object with particle acceleration up to energies of several hundred TeV. Contrary to most H.E.S.S. unidentified sources, the angular size of HESS J1741-302 is compatible with the H.E.S.S. point spread function at VHEs, with an extension constrained to be below 0.068° at a 99% confidence level. The γ-ray emission detected by H.E.S.S. can be explained both within a hadronic scenario, due to collisions of protons with energies of hundreds of TeV with dense molecular clouds, and in a leptonic scenario, as a relic pulsar wind nebula, possibly powered by the middle-aged (20 kyr) pulsar PSR B1737-30. A binary scenario, related to the compact radio source 1LC 358.266+0.038 found to be spatially coincident with the best fit position of HESS J1741-302, is also envisaged.« less

HESS J1741-302: a hidden accelerator in the Galactic plane

DOE PAGES

Abdalla, H.; Abramowski, A.; Aharonian, F.; ...

2018-04-01

The H.E.S.S. Collaboration has discovered a new very high energy (VHE, E > 0.1 TeV) γ-ray source, HESS J1741-302, located in the Galactic plane. Despite several attempts to constrain its nature, no plausible counterpart has been found so far at X-ray and MeV/GeV γ-ray energies, and the source remains unidentified. An analysis of 145-h of observations of HESS J1741-302 at VHEs has revealed a steady and relatively weak TeV source (~1% of the Crab Nebula flux), with a spectral index of Γ = 2.3 ± 0.2stat ± 0.2sys, extending to energies up to 10 TeV without any clear signature ofmore » a cut-off. In a hadronic scenario, such a spectrum implies an object with particle acceleration up to energies of several hundred TeV. Contrary to most H.E.S.S. unidentified sources, the angular size of HESS J1741-302 is compatible with the H.E.S.S. point spread function at VHEs, with an extension constrained to be below 0.068° at a 99% confidence level. The γ-ray emission detected by H.E.S.S. can be explained both within a hadronic scenario, due to collisions of protons with energies of hundreds of TeV with dense molecular clouds, and in a leptonic scenario, as a relic pulsar wind nebula, possibly powered by the middle-aged (20 kyr) pulsar PSR B1737-30. A binary scenario, related to the compact radio source 1LC 358.266+0.038 found to be spatially coincident with the best fit position of HESS J1741-302, is also envisaged.« less

Characterization of bacterial diversity in an atrazine degrading enrichment culture and degradation of atrazine, cyanuric acid and biuret in industrial wastewater.

PubMed

Dutta, Anirban; Vasudevan, Venugopal; Nain, Lata; Singh, Neera

2016-01-01

An enrichment culture was used to study atrazine degradation in mineral salt medium (MSM) (T1), MSM+soil extract (1:1, v/v) (T2) and soil extract (T3). Results suggested that enrichment culture required soil extract to degrade atrazine, as after second sequential transfer only partial atrazine degradation was observed in T1 treatment while atrazine was completely degraded in T2 and T3 treatments even after fourth transfer. Culture independent polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique confirmed selective enrichment of genus Bacillus along with Pseudomonas and Burkholderia. Degradation of atrazine/metabolites in the industrial wastewater was studied at different initial concentrations of the contaminants [wastewater-water (v/v) ratio: T1, 1:9; T2, 2:8; T3, 3:7; T4, 5:5 and T5, undiluted effluent]. The initial concentrations of atrazine, cyanuric acid and biuret ranged between 5.32 and 53.92 µg mL(-1), 265.6 and 1805.2 µg mL(-1) and 1.85 and 16.12 µg mL(-1), respectively. The enrichment culture was able to completely degrade atrazine, cyanuric acid and biuret up to T4 treatment, while no appreciable degradation of contaminants was observed in the undiluted effluent (T5). Inability of enrichment culture to degrade atrazine/metabolites might be due to high concentrations of cyanuric acid. Therefore, a separate study on cyanuric acid degradation suggested: (i) no appreciable cyanuric acid degradation with accumulation of an unidentified metabolite in the medium where cyanuric acid was supplemented as the sole source of carbon and nitrogen; (ii) partial cyanuric acid degradation with accumulation of unidentified metabolite in the medium containing additional nitrogen source; and (iii) complete cyanuric acid degradation in the medium supplemented with an additional carbon source. This unidentified metabolite observed during cyanuric acid degradation and also detected in the enrichment culture inoculated wastewater samples, however, was degraded up to T4 treatments and was persistent in the T5 treatment. Probably, accumulation of this metabolite inhibited atrazine/cyanuric acid degradation by the enrichment culture in undiluted wastewater.

Cryobacterium aureum sp. nov., a psychrophilic bacterium isolated from glacier ice collected from the ice tongue surface.

PubMed

Liu, Qing; Xin, Yu-Hua; Chen, Xiu-Ling; Liu, Hong-Can; Zhou, Yu-Guang; Chen, Wen-Xin

2018-04-01

A psychrophilic, Gram-stain-positive, rod-shaped bacterium, designated strain Hh31 T , was isolated from Xinjiang No. 1 Glacier in China. Strain Hh31 T was catalase-positive, oxidase-negative and able to grow at between 0-18 °C. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain Hh31 T belonged to the genus Cryobacterium and was most closely related to the type strains of Cryobacterium levicorallinum, Cryobacterium luteum and Cryobacterium flavum. DNA-DNA hybridization, calculation of average nucleotide identity and digital DNA-DNA hybridization revealed that strain Hh31 T was distinct from its closest phylogenetic neighbours. The major cellular fatty acids of strain Hh31 T were anteiso-C15 : 0, anteiso-C15 : 1, iso-C15:0, iso-C16 : 0 and anteiso-C17 : 0. The predominant menaquinones of strain Hh31 T were MK-9 and MK-10. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, one unidentified phospholipid, one unidentified glycolipid and another unidentified lipid. Physiological tests such as carbon source utilization, showed phenotypic differentiation of strain Hh31 T from the closest related phylogenetic neighbours. Based on a polyphasic approach, a novel species, Cryobacterium aureum sp. nov., is proposed, with Hh31 T (=NBRC 107882 T =CGMCC 1.11213 T ) as the type strain.

Possible sources of nitrate in ground water at swine licensed-managed feeding operations in Oklahoma, 2001

USGS Publications Warehouse

Becker, Mark F.; Peter, Kathy D.; Masoner, Jason

2002-01-01

Samples collected and analyzed by the Oklahoma Department of Agriculture, Food, and Forestry from 1999 to 2001 determined that nitrate exceeded the U.S. Environmental Protection Agency maximum contaminant level for public drinking-water supplies of 10 milligrams per liter as nitrogen in 79 monitoring wells at 35 swine licensed-managed feeding operations (LMFO) in Oklahoma. The LMFOs are located in rural agricultural settings where long-term agriculture has potentially affected the ground-water quality in some areas. Land use prior to the construction of the LMFOs was assessed to evaluate the types of agricultural land use within a 500-meter radius of the sampled wells. Chemical and microbiological techniques were used to determine the possible sources of nitrate in water sampled from 10 wastewater lagoons and 79 wells. Samples were analyzed for dissolved major ions, dissolved trace elements, dissolved nutrients, nitrogen isotope ratios of nitrate and ammonia, wastewater organic compounds, and fecal coliform bacteria. Bacteria ribotyping analysis was done on selected samples to identify possible specific animal sources. A decision process was developed to identify the possible sources of nitrate. First, nitrogen isotope ratios were used to define sources as animal, mixed animal and fertilizer, or fertilizer. Second, wastewater organic compound detections, nitrogen-isotope ratios, fecal coliform bacteria detections, and ribotyping were used to refine the identification of possible sources as LFMO waste, fertilizer, or unidentified animal or mixtures of these sources. Additional evidence provided by ribotyping and wastewater organic compound data can, in some cases, specifically indicate the animal source. Detections of three or more wastewater organic compounds that are indicators of animal sources and detections of fecal coliform bacteria provided additional evidence of an animal source. LMFO waste was designated as a possible source of nitrate in water from 10 wells. The source of waste in water from five of those wells was determined through ribotyping, and the source of waste in water from the remaining five wells was determined by detections of three or more animal-waste compounds in the well samples. LMFO waste in the water from wells with unidentified animal source of nitrate does not indicate that LMFO waste was not the source, but indicated that multiple animal sources, including LMFO waste, may be the source of the nitrate.

Recognizing millions of consistently unidentified spectra across hundreds of shotgun proteomics datasets

PubMed Central

Griss, Johannes; Perez-Riverol, Yasset; Lewis, Steve; Tabb, David L.; Dianes, José A.; del-Toro, Noemi; Rurik, Marc; Walzer, Mathias W.; Kohlbacher, Oliver; Hermjakob, Henning; Wang, Rui; Vizcaíno, Juan Antonio

2016-01-01

Mass spectrometry (MS) is the main technology used in proteomics approaches. However, on average 75% of spectra analysed in an MS experiment remain unidentified. We propose to use spectrum clustering at a large-scale to shed a light on these unidentified spectra. PRoteomics IDEntifications database (PRIDE) Archive is one of the largest MS proteomics public data repositories worldwide. By clustering all tandem MS spectra publicly available in PRIDE Archive, coming from hundreds of datasets, we were able to consistently characterize three distinct groups of spectra: 1) incorrectly identified spectra, 2) spectra correctly identified but below the set scoring threshold, and 3) truly unidentified spectra. Using a multitude of complementary analysis approaches, we were able to identify less than 20% of the consistently unidentified spectra. The complete spectrum clustering results are available through the new version of the PRIDE Cluster resource (http://www.ebi.ac.uk/pride/cluster). This resource is intended, among other aims, to encourage and simplify further investigation into these unidentified spectra. PMID:27493588

Recognizing millions of consistently unidentified spectra across hundreds of shotgun proteomics datasets.

PubMed

Griss, Johannes; Perez-Riverol, Yasset; Lewis, Steve; Tabb, David L; Dianes, José A; Del-Toro, Noemi; Rurik, Marc; Walzer, Mathias W; Kohlbacher, Oliver; Hermjakob, Henning; Wang, Rui; Vizcaíno, Juan Antonio

2016-08-01

Mass spectrometry (MS) is the main technology used in proteomics approaches. However, on average 75% of spectra analysed in an MS experiment remain unidentified. We propose to use spectrum clustering at a large-scale to shed a light on these unidentified spectra. PRoteomics IDEntifications database (PRIDE) Archive is one of the largest MS proteomics public data repositories worldwide. By clustering all tandem MS spectra publicly available in PRIDE Archive, coming from hundreds of datasets, we were able to consistently characterize three distinct groups of spectra: 1) incorrectly identified spectra, 2) spectra correctly identified but below the set scoring threshold, and 3) truly unidentified spectra. Using a multitude of complementary analysis approaches, we were able to identify less than 20% of the consistently unidentified spectra. The complete spectrum clustering results are available through the new version of the PRIDE Cluster resource (http://www.ebi.ac.uk/pride/cluster). This resource is intended, among other aims, to encourage and simplify further investigation into these unidentified spectra.

Subchronic effects of methylmercury on plasma and organ biochemistries in great egret nestlings

USGS Publications Warehouse

Hoffman, D.J.; Spalding, M.G.; Frederick, P.C.

2005-01-01

In recent years, high concentrations of mercury have been found in wading birds in Florida, USA. Great egret (Ardea alba) chicks (2 weeks old) were dosed orally daily with the equivalent of 0, 0.5, or 5 ug/g Hg as methylmercury chloride in the diet for up to 12 weeks. Weakness of the legs or paralysis occurred in all high-dosed birds. Geometric mean blood Hg concentrations were 0.17, 10.3, and 78.5 ug/g (wet wt), respectively. Mercury concentrations for organs (ug/g wet wt), including brain (0.22, 3.4, and 35, respectively), liver (0.34, 15.1, 138, respectively), and kidney (0.28, 8.1, and 120, respectively), increased in a dose-dependent manner. Total glutathione (GSH) peroxidase activity was significantly lower in the plasma, brain, liver, and kidney of the high-dosed group. Plasma aspartate aminotransferase activity increased with mercury treatment, whereas lactate dehydrogenase activity decreased. Four other plasma chemistries were decreased significantly in the high-dosed group and included uric acid, total protein, albumin, and inorganic phosphorus. Lipid peroxidation increased in liver (low and high dose) and brain (high dose). Tissue changes in concentrations of reduced thiols included decreased total thiols and protein-bound thiols in liver, decreased protein-bound thiols in kidney, and increased GSH in kidney and brain. Activities of GSH S-transferase and oxidized glutathione reductase increased in liver. In kidney, GSH S-transferase and glucose-6-phosphate dehydrogenase activities increased with mercury dose. These findings, including apparent compensatory changes, are compared to other Hg studies where oxidative stress was reported in egrets, herons, and diving ducks in the field and mallards in the laboratory.

The Einstein@Home Gamma-ray Pulsar Survey. I. Search Methods, Sensitivity, and Discovery of New Young Gamma-Ray Pulsars

NASA Astrophysics Data System (ADS)

Clark, C. J.; Wu, J.; Pletsch, H. J.; Guillemot, L.; Allen, B.; Aulbert, C.; Beer, C.; Bock, O.; Cuéllar, A.; Eggenstein, H. B.; Fehrmann, H.; Kramer, M.; Machenschalk, B.; Nieder, L.

2017-01-01

We report on the results of a recent blind search survey for gamma-ray pulsars in Fermi Large Area Telescope (LAT) data being carried out on the distributed volunteer computing system, Einstein@Home. The survey has searched for pulsations in 118 unidentified pulsar-like sources, requiring about 10,000 years of CPU core time. In total, this survey has resulted in the discovery of 17 new gamma-ray pulsars, of which 13 are newly reported in this work, and an accompanying paper. These pulsars are all young, isolated pulsars with characteristic ages between 12 kyr and 2 Myr, and spin-down powers between 1034 and 4 × 1036 erg s-1. Two of these are the slowest spinning gamma-ray pulsars yet known. One pulsar experienced a very large glitch {{Δ }}f/f≈ 3.5× {10}-6 during the Fermi mission. In this, the first of two associated papers, we describe the search scheme used in this survey, and estimate the sensitivity of our search to pulsations in unidentified Fermi-LAT sources. One such estimate results in an upper limit of 57% for the fraction of pulsed emission from the gamma-ray source associated with the Cas A supernova remnant, constraining the pulsed gamma-ray photon flux that can be produced by the neutron star at its center. We also present the results of precise timing analyses for each of the newly detected pulsars.

The global carbon dioxide budget

USGS Publications Warehouse

Sundquist, E.T.

1993-01-01

The increase in atmospheric CO2 levels during the last deglaciation was comparable in magnitude to the recent historical increase. However, global CO2 budgets for these changes reflect fundamental differences in rates and in sources and sinks. The modern oceans are a rapid net CO2 sink, whereas the oceans were a gradual source during the deglaciation. Unidentified terrestrial CO2 sinks are important uncertainties in both the deglacial and recent CO2 budgets. The deglacial CO2 budget represents a complexity of long-term dynamic behavior that is not adequately addressed by current models used to forecast future atmospheric CO2 levels.

Development of the instruments for the Gamma Ray Observatory

NASA Technical Reports Server (NTRS)

Madden, J. J.; Kniffen, D. A.

1986-01-01

The Gamma Ray Observatory (GRO) is to be launched in 1988 by the STS. The GRO will feature four very large instruments: the Oriented Scintillation Spectrometer Experiment (OSSE), the Imaging Compton Telescope (COMPTEL), the Energetic Gamma Ray Experiment Telescope (EGRET) and the Burst and Transient Source Experiment (BATSE). The instruments weigh from 900-1200 kg each, and required the development of specialized lifting and dolly devices to permit their assembly, manipulation and testing. The GRO is intended a{s a tool for studying discrete celestial objects such as black holes, neutron stars and other gamma-ray emitting objects, scanning for nucleosynthesis processes, mapping the Galaxy and other, high energy galaxies in terms of gamma rays, searching for cosmological effects and observing gamma ray bursts. The instruments will be sensitive from the upper end mof X-rya wavelengths to the highest energies possible. Details of the hardware and performance specifications of each of the instruments are discussed.

Spectrum of the isotropic diffuse gamma-ray emission derived from first-year Fermi Large Area Telescope data.

PubMed

Abdo, A A; Ackermann, M; Ajello, M; Atwood, W B; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Baughman, B M; Bechtol, K; Bellazzini, R; Berenji, B; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Bregeon, J; Brez, A; Brigida, M; Bruel, P; Burnett, T H; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Cavazzuti, E; Cecchi, C; Celik, O; Charles, E; Chekhtman, A; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Cominsky, L R; Conrad, J; Cutini, S; Dermer, C D; de Angelis, A; de Palma, F; Digel, S W; Di Bernardo, G; do Couto e Silva, E; Drell, P S; Drlica-Wagner, A; Dubois, R; Dumora, D; Farnier, C; Favuzzi, C; Fegan, S J; Focke, W B; Fortin, P; Frailis, M; Fukazawa, Y; Funk, S; Fusco, P; Gaggero, D; Gargano, F; Gasparrini, D; Gehrels, N; Germani, S; Giebels, B; Giglietto, N; Giommi, P; Giordano, F; Glanzman, T; Godfrey, G; Grenier, I A; Grondin, M-H; Grove, J E; Guillemot, L; Guiriec, S; Gustafsson, M; Hanabata, Y; Harding, A K; Hayashida, M; Hughes, R E; Itoh, R; Jackson, M S; Jóhannesson, G; Johnson, A S; Johnson, R P; Johnson, T J; Johnson, W N; Kamae, T; Katagiri, H; Kataoka, J; Kawai, N; Kerr, M; Knödlseder, J; Kocian, M L; Kuehn, F; Kuss, M; Lande, J; Latronico, L; Lemoine-Goumard, M; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Madejski, G M; Makeev, A; Mazziotta, M N; McConville, W; McEnery, J E; Meurer, C; Michelson, P F; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nolan, P L; Norris, J P; Nuss, E; Ohsugi, T; Omodei, N; Orlando, E; Ormes, J F; Paneque, D; Panetta, J H; Parent, D; Pelassa, V; Pepe, M; Pesce-Rollins, M; Piron, F; Porter, T A; Rainò, S; Rando, R; Razzano, M; Reimer, A; Reimer, O; Reposeur, T; Ritz, S; Rochester, L S; Rodriguez, A Y; Roth, M; Ryde, F; Sadrozinski, H F-W; Sanchez, D; Sander, A; Saz Parkinson, P M; Scargle, J D; Sellerholm, A; Sgrò, C; Shaw, M S; Siskind, E J; Smith, D A; Smith, P D; Spandre, G; Spinelli, P; Starck, J-L; Strickman, M S; Strong, A W; Suson, D J; Tajima, H; Takahashi, H; Takahashi, T; Tanaka, T; Thayer, J B; Thayer, J G; Thompson, D J; Tibaldo, L; Torres, D F; Tosti, G; Tramacere, A; Uchiyama, Y; Usher, T L; Vasileiou, V; Vilchez, N; Vitale, V; Waite, A P; Wang, P; Winer, B L; Wood, K S; Ylinen, T; Ziegler, M

2010-03-12

We report on the first Fermi Large Area Telescope (LAT) measurements of the so-called "extragalactic" diffuse gamma-ray emission (EGB). This component of the diffuse gamma-ray emission is generally considered to have an isotropic or nearly isotropic distribution on the sky with diverse contributions discussed in the literature. The derivation of the EGB is based on detailed modeling of the bright foreground diffuse Galactic gamma-ray emission, the detected LAT sources, and the solar gamma-ray emission. We find the spectrum of the EGB is consistent with a power law with a differential spectral index gamma = 2.41 +/- 0.05 and intensity I(>100 MeV) = (1.03 +/- 0.17) x 10(-5) cm(-2) s(-1) sr(-1), where the error is systematics dominated. Our EGB spectrum is featureless, less intense, and softer than that derived from EGRET data.

Plastic scintillator block as photon beam monitor for EGRET calibration

NASA Technical Reports Server (NTRS)

Lin, Y. C.; Hofstadter, R.; Nolan, P. L.; Walker, A. H.; Mattox, J. R.; Hughes, E. B.

1991-01-01

The EGRET (Energetic Gamma Ray Experiment Telescope) detector has been calibrated at SLAC (Stanford Linear Accelerator) and, to a lesser degree, at the MIT Bates Linear Accelerator Center. To monitor the photon beams for the calibration, a plastic scintillator block, 5 cm x 5 cm in cross section, 15 cm in length, and viewed by a single photomultiplier tube, was used for the entire beam energy range of 15 MeV to 10 GeV. The design operation, and method of analysis of the beam intensity are presented. A mathematical framework has been developed to treat the general case of a beam with multiphoton beam pulses and with a background component. A procedure to deal with the fluctuations of the beam intensity over a data-taking period was also developed. The photon beam monitor is physically sturdy, electronically steady, simple to construct, and easy to operate. Its major merits lie in its sheer simplicity of construction and operation and in the wide energy range it can cover.

KENNEDY SPACE CENTER, FLA. - A great blue heron patiently stalks its prey in the marshes around KSC. The heron is one of 310 species of birds that inhabit the National Merritt Island Wildlife Refuge, which shares a boundary with KSC. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

NASA Image and Video Library

2003-10-24

KENNEDY SPACE CENTER, FLA. - A great blue heron patiently stalks its prey in the marshes around KSC. The heron is one of 310 species of birds that inhabit the National Merritt Island Wildlife Refuge, which shares a boundary with KSC. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

KENNEDY SPACE CENTER, FLA. - A great blue heron swoops down for a landing on the water near KSC. The heron is one of 310 species of birds that inhabit the National Merritt Island Wildlife Refuge, which shares a boundary with KSC. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

NASA Image and Video Library

2003-10-24

KENNEDY SPACE CENTER, FLA. - A great blue heron swoops down for a landing on the water near KSC. The heron is one of 310 species of birds that inhabit the National Merritt Island Wildlife Refuge, which shares a boundary with KSC. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

GLAST answers about high-energy peaked BL Lacs: double-humped {gamma}-ray peak and extreme accelerators?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Costamante, L.; Aharonian, F.; Khangulyan, D.

2007-07-12

An often overlooked fact is that the MeV-GeV emission from High-energy peaked BL Lacs (HBL) is basically unknown: there are only 3 objects of this type among all EGRET identified blazars with measured spectra. GLAST will be able to measure the spectrum for many of them, in particular TeV-blazars, and surprises are expected. GLAST will tell if the {gamma}-ray peak in some HBL is actually a ''double peak'', as suggested by the comparison of EGRET and HESS data in PKS 2155-304, We also remind and argue that a new class of BL Lacs could exist, where particles are shock-accelerated nearmore » the maximum possible rate, characterized by the synchrotron emission peaking in the GLAST band (100 MeV - few GeV). Such objects could easily have escaped detection or identification so far, and could now be unveiled by GLAST.« less

Dispersal and habitat use by post-fledging juvenile snowy egrets and black-crowned night-herons

USGS Publications Warehouse

Erwin, R.M.; Haig, J.G.; Stotts, D.B.; Hatfield, J.S.

1996-01-01

We studied the postfledging dispersal movements and habitat use of juvenile Snowy Egrets (Egretta thula) (SNEG) and Black-crowned Night-Herons (Nycticorax nycticorax) (BCNH) in coastal Virginia using a dye (picric acid) and radiotelemetry. Results from monitoring radiomarked birds revealed significant differences both years between species, with SNEGs dispersing more widely than BCNHs. BCNH juveniles usually remained south of Delaware, but SNEGs often moved into Delaware and southern New Jersey. The maximum dispersal distance found for a SNEG was ca 340 km north of the natal colony. Temporal patterns of movement followed logistic relationships, with rapid initial movements, but relatively few movements after about 23 weeks for most birds. Cumulative distances moved by juvenile SNEGs during AugustSeptember differed from 1992 to 1993. No such year difference was found for BCNHs. Compared to SNEGs, BCNHs used man-made impoundments relatively more often than natural wetlands; however no quantitative assessment of habitat preferences could be made.

Results from the energetic gamma-ray experiment telescope (EGRET) on the Compton Observatory

NASA Technical Reports Server (NTRS)

Fichtel, C. E.; Bertsch, D. L.; Dingus, B.; Hartman, R. C.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Kwok, P. W.; Lin, Y. C.; Mattox, J. R.

1993-01-01

The Energetic Gamma-Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory (CGRO) covers the high energy gamma ray energy range, approximately 30 MeV to 30 GeV, with a sensitivity considerably greater than earlier high energy gamma-ray satellites. Thus far, 4 pulsars have been detected and their properties measured, including in 3 cases the energy spectrum as a function of phase. The details of the galactic plane are being mapped and a spectra of the center region has been obtained in good agreement with that expected from cosmic ray interactions. The Magellanic clouds have been examined with the Large Magellanic Cloud (LMC) having been detected at a level consistent with it having a cosmic ray density compatible with quasi-stable equilibrium. Sixteen Active Galactic Nuclei (AGN's) have been seen thus far with a high degree of certainty including 12 quasars and 4 BL Lac objects, but no Seyferts. Time variation has been detected in some of these AGN's

Prospects for Pulsar Studies with the GLAST Large Area Telescope

NASA Technical Reports Server (NTRS)

Harding, Alice K.

2007-01-01

The Large Area Telescope (LAT) on the Gamma-ray Large Area Space Telescope (GLAST), due to launch in November 2007, will have unprecedented sensitivity and energy resolution for gamma-rays in the range of 30 MeV to 200 GeV. GLAST is therefore expected to provide major advances in the understanding of high-energy emission from rotation-powered p ulsars. As the only presently known galactic GeV source class, pulsar s will be one of the most important sources for study with GLAST. The main science goals of the LAT for pulsar studies include an increase in the number of detected radio-loud and radio-quiet gamma-ray pulsar s, including millisecond pulsars, giving much better statistics for e lucidating population characteristics, measurement of the high-energy spectrum and the shape of spectral cutoffs and determining pulse profiles for a variety of pulsars of different age. Further, measurement of phase-resolved spectra and energy dependent pulse profiles of the brighter pulsars should allow detailed tests of magnetospheric partic le acceleration and radiation mechanisms, by comparing data with theo retical models that have been developed. Additionally, the LAT will have the sensitivity to allow blind pulsation searches of nearly all un identified EGRET sources, to possibly uncover more radio-quiet Geming a-like pulsars.

Aquatic Habitat Studies on the Lower Mississippi River, River Mile 480 to 530. Report 6. Larval Fish Studies-Pilot Report.

DTIC Science & Technology

1981-04-01

larval fish were collected: unidentified clupeids, unidentified cyprinids, Carpiodes spp., Menidia audens , Lepomis spp., unidentified centrarchids, and...bars, was rare in both abandoned channels and oxbow lakes. 69. Menidia audens and Morone spp. were common in the abandoned channel habitat and rare in

Probing for Pulsars: An XMM Study of the Composite SNRS G327.1-1.1 and CTA1

NASA Technical Reports Server (NTRS)

Slane, Patrick; Mushotzky, Richard F. (Technical Monitor)

2003-01-01

The subject grant is for analysis of XMM data from the supernova remnant CTA1. Our investigation centered on the study of the compact source Rx 50007.0+7302 that, based on our previous observations, appears to be a neutron star powering a wind nebula in the remnant interior. This compact source has also been suggested as the counterpart of the EGRET source 2EG J0008+7307. The analysis of the data from the compact source is complete. We find that the spectrum of the source is well described by a power law with the addition of a soft thermal component that may correspond to emission from hot polar cap regions or to cooling emission from a light element atmosphere over the entire star. There is evidence of extended emission on small spatial scales which may correspond to structure in the underlying synchrotron nebula. Extrapolation of the nonthermal emission component to gamma-ray energies yields a flux that is consistent with that of 2EG J0008+7307, thus strengthening the proposition that there is a gamma-ray emitting pulsar at the center of CTA 1. Our timing studies with the EPIC pn data revealed no evidence for pulsations, however; we set an upper limit of 61% on the pulsed fraction from this source. The results from this study were presented in a poster at the recent IAU Symposium in Sydney, Australia. A paper summarizing these results, entitled "Xray Observations of the Compact Source in CTA 1" (Slane et al.) has been submitted for publication in the Astrophysical Journal.

The ROSAT Deep Survey. 2; Optical Identification, Photometry and Spectra of X-Ray Sources in the Lockman Field

NASA Technical Reports Server (NTRS)

Schmidt, M.; Hasinger, G.; Gunn, J.; Schneider, D.; Burg, R.; Giacconi, R.; Lehmann, I.; MacKenty, J.; Truemper, J.; Zamorani, G.

1998-01-01

The ROSAT Deep Survey includes a complete sample of 50 X-ray sources with fluxes in the 0.5 - 2 keV band larger than 5.5 x 10(exp -15)erg/sq cm/s in the Lockman field (Hasinger et al., Paper 1). We have obtained deep broad-band CCD images of the field and spectra of many optical objects near the positions of the X-ray sources. We define systematically the process leading to the optical identifications of the X-ray sources. For this purpose, we introduce five identification (ID) classes that characterize the process in each case. Among the 50 X-ray sources, we identify 39 AGNs, 3 groups of galaxies, 1 galaxy and 3 galactic stars. Four X-ray sources remain unidentified so far; two of these objects may have an unusually large ratio of X-ray to optical flux.

Deinococcus metallilatus sp. nov. and Deinococcus carri sp. nov., isolated from a car air-conditioning system.

PubMed

Kim, Dong-Uk; Lee, Hyosun; Lee, Ji-Hyeong; Ahn, Jae-Hyung; Lim, Sangyong; Jeong, Sunwook; Park, So Yoon; Seong, Chi Nam; Ka, Jong-Ok

2015-09-01

Two bacterial strains, designated MA1002(T) and MA1003(T), were isolated from the air-conditioning system of a car. Cells of both strains were Gram-reaction-positive, non-motile, non-spore-forming coccoids, catalase- and oxidase-positive and UV-radiation resistant. The major fatty acids of strain MA1002(T) were iso-C17 : 0 and iso-C15 : 0 and those of strain MA1003(T) were iso-C16 : 0 and iso-C16 : 1 H. The polar lipid profile of MA1002(T) contained phosphatidylethanolamine, two unidentified phosphoglycolipids, an unidentified phospholipid, an unidentified aminophospholipid, an unidentified aminolipid and an unidentified lipid. MA1003(T) had three unidentified phosphoglycolipids, six unidentified phospholipids, two unidentified glycolipids and two unidentified polar lipids as the polar lipids. The G+C contents of the genomic DNA of MA1002(T) and MA1003(T) were 70.5 and 76.0 mol%, respectively. MK-8 was the predominant respiratory quinone for both strains. 16S rRNA gene sequence analysis showed that strain MA1002(T) was phylogenetically related to Deinococcus apachensis DSM 19763(T), D. geothermalis DSM 11300(T), D. aerius TR0125(T) and D. aetherius ST0316(T) (92.9, 92.6, 92.0 and 91.9% sequence similarity, respectively), and MA1003(T) showed the highest sequence similarity to Deinococcus hopiensis KR-140(T) (92.9%) and D. xinjiangensis X-82(T) (91.4%). The results of genotypic and phenotypic characterizations showed that both strains could be distinguished from phylogenetically related species, and that the strains represented novel species within the genus Deinococcus, for which we propose the names Deinococcus metallilatus sp. nov. (type strain MA1002(T) = KACC 17964(T) = NBRC 110141(T)) and Deinococcus carri sp. nov. (type strain is MA1003(T) = KACC 17965(T) = NBRC 110142(T)).

Stable Isotope-Assisted Metabolic Profiling Reveals Growth Mode Dependent Differential Metabolism and Multiple Catabolic Pathways of l-Phenylalanine in Rubrivivax benzoatilyticus JA2.

PubMed

Mekala, Lakshmi Prasuna; Mohammed, Mujahid; Chintalapati, Sasikala; Chintalapati, Venkata Ramana

2018-01-05

Anoxygenic phototrophic bacteria are metabolically versatile and survive under different growth modes using diverse organic compounds, yet their metabolic diversity is largely unexplored. In the present study, we employed stable-isotope-assisted metabolic profiling to unravel the l-phenylalanine catabolism in Rubrivivax benzoatilyticus JA2 under varying growth modes. Strain JA2 grows under anaerobic and aerobic conditions by utilizing l-phenylalanine as a nitrogen source. Furthermore, ring-labeled 13 C 6 -phenylalanine feeding followed by liquid chromatography-mass spectrometry exometabolite profiling revealed 60 labeled metabolic features (M + 6, M + 12, and M + 18) derived solely from l-phenylalanine, of which 11 were identified, 7 putatively identified, and 42 unidentified under anaerobic and aerobic conditions. However, labeled metabolites were significantly higher in aerobic compared to anaerobic conditions. Furthermore, detected metabolites and enzyme activities indicated multiple l-phenylalanine catabolic routes mainly Ehrlich, homogentisate-dependent melanin, benzenoid, and unidentified pathways operating under anaerobic and aerobic conditions in strain JA2. Interestingly, the study indicated l-phenylalanine-dependent and independent benzenoid biosynthesis in strain JA2 and a differential flux of l-phenylalanine to Ehrlich and benzenoid pathways under anaerobic and aerobic conditions. Additionally, unidentified labeled metabolites strongly suggest the presence of unknown phenylalanine catabolic routes in strain JA2. Overall, the study uncovered the l-phenylalanine catabolic diversity in strain JA2 and demonstrated the potential of stable isotope-assisted metabolomics in unraveling the hidden metabolic repertoire.

Sources and sinks of formic, acetic, and pyruvic acids over central Amazonia. II - Wet season

NASA Technical Reports Server (NTRS)

Talbot, R. W.; Andreae, M. O.; Berresheim, H.; Jacob, D. J.; Beecher, K. M.

1990-01-01

Potential sources and sinks of formic, acetic, and pyruvic acids over the Amazon forest were investigated using a photochemical model and data collected on gas phase concentrations of these acids in the forest canopy, boundary layer, and free troposphere over the central Amazon Basin during the 1987 wet season. It was found that the atmospheric reactions previously suggested in the literature as sources of carboxylic acids (i.e., the gas phase decomposition of isoprene, the reaction between CH3CO3 and a peroxide, and aqueous phase oxidation of CH2O) appear to be too slow to explain the observed concentrations, suggesting that other atmospheric reactions, so far unidentified, could make a major contribution to the carboxylic acid budgets.

Wildlife Photography - Birds

NASA Image and Video Library

2017-05-04

A snowy egret perches on a branch at the shoreline of a waterway at NASA's Kennedy Space Center in Florida. The center shares a border with the Merritt Island National Wildlife Refuge. More than 330 native and migratory bird species, 25 mammals, 117 fishes and 65 amphibians and reptiles call Kennedy and the wildlife refuge home.

Creative Photography - Wildlife

NASA Image and Video Library

2016-03-25

A snowy egret successfully catches a small fish in a shallow waterway at Merritt Island National Wildlife Refuge in Florida. NASA’s Kennedy Space Center shares boundaries with the refuge, which is home to more than 330 native and migratory bird species, along with 25 mammal, 117 fish, and 65 amphibian and reptile species.

Air to air views of Endeavour, Orbiter Vehicle (OV) 105

NASA Image and Video Library

1959-01-01

Air to air views of Endeavour, Orbiter Vehicle (OV) 105, transported via the Shuttle Carrier Aircraft (SCA), NASA 911, on its way to KSC, 05-06-91. JSC with Clear Creek and Egret Bay Blvd in the foreground and Clear Lake and Galveston Bay in the background

75 FR 35080 - Tampa Bay Refuges, FL

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-21

... species. It contains 7 mangrove islands encompassing about 394 acres. The refuge is comprised of Little... Tarpon and Little Bird Keys. Pinellas NWR provides important mangrove habitat for most long-legged wading species, especially the reddish egret. All of the mangrove islands of Pinellas NWR are closed to all...

THE EINSTEIN@HOME GAMMA-RAY PULSAR SURVEY. I. SEARCH METHODS, SENSITIVITY, AND DISCOVERY OF NEW YOUNG GAMMA-RAY PULSARS

DOE PAGES

Clark, C. J.; Wu, J.; Pletsch, H. J.; ...

2017-01-05

Here, we report on the results of a recent blind search survey for gamma-ray pulsars in Fermi Large Area Telescope (LAT) data being carried out on the distributed volunteer computing system, Einstein@Home. The survey has searched for pulsations in 118 unidentified pulsar-like sources, requiring about 10,000 years of CPU core time. In total, this survey has resulted in the discovery of 17 new gamma-ray pulsars, of which 13 are newly reported in this work, and an accompanying paper. These pulsars are all young, isolated pulsars with characteristic ages between 12 kyr and 2 Myr, and spin-down powers between 10 34 and 4 × 10 36 erg s -1. Two of these are the slowest spinning gamma-ray pulsars yet known. One pulsar experienced a very large glitchmore » $${\\rm{\\Delta }}f/f\\approx 3.5\\times {10}^{-6}$$ during the Fermi mission. In this, the first of two associated papers, we describe the search scheme used in this survey, and estimate the sensitivity of our search to pulsations in unidentified Fermi-LAT sources. One such estimate results in an upper limit of 57% for the fraction of pulsed emission from the gamma-ray source associated with the Cas A supernova remnant, constraining the pulsed gamma-ray photon flux that can be produced by the neutron star at its center. Lastly, we also present the results of precise timing analyses for each of the newly detected pulsars.« less

THE EINSTEIN@HOME GAMMA-RAY PULSAR SURVEY. I. SEARCH METHODS, SENSITIVITY, AND DISCOVERY OF NEW YOUNG GAMMA-RAY PULSARS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clark, C. J.; Wu, J.; Pletsch, H. J.

Here, we report on the results of a recent blind search survey for gamma-ray pulsars in Fermi Large Area Telescope (LAT) data being carried out on the distributed volunteer computing system, Einstein@Home. The survey has searched for pulsations in 118 unidentified pulsar-like sources, requiring about 10,000 years of CPU core time. In total, this survey has resulted in the discovery of 17 new gamma-ray pulsars, of which 13 are newly reported in this work, and an accompanying paper. These pulsars are all young, isolated pulsars with characteristic ages between 12 kyr and 2 Myr, and spin-down powers between 10 34 and 4 × 10 36 erg s -1. Two of these are the slowest spinning gamma-ray pulsars yet known. One pulsar experienced a very large glitchmore » $${\\rm{\\Delta }}f/f\\approx 3.5\\times {10}^{-6}$$ during the Fermi mission. In this, the first of two associated papers, we describe the search scheme used in this survey, and estimate the sensitivity of our search to pulsations in unidentified Fermi-LAT sources. One such estimate results in an upper limit of 57% for the fraction of pulsed emission from the gamma-ray source associated with the Cas A supernova remnant, constraining the pulsed gamma-ray photon flux that can be produced by the neutron star at its center. Lastly, we also present the results of precise timing analyses for each of the newly detected pulsars.« less

What remains after 2 months of starvation? Analysis of sequestered algae in a photosynthetic slug, Plakobranchus ocellatus (Sacoglossa, Opisthobranchia), by barcoding.

PubMed

Christa, Gregor; Wescott, Lily; Schäberle, Till F; König, Gabriele M; Wägele, Heike

2013-02-01

The sacoglossan sea slug, Plakobranchus ocellatus, is a so-called long-term retention form that incorporates chloroplasts for several months and thus is able to starve while maintaining photosynthetic activity. Little is known regarding the taxonomy and food sources of this sacoglossan, but it is suggested that P. ocellatus is a species complex and feeds on a broad variety of Ulvophyceae. In particular, we analysed specimens from the Philippines and starved them under various light conditions (high light, low light and darkness) and identified the species of algal food sources depending on starvation time and light treatment by means of DNA-barcoding using for the first time the combination of two algal chloroplast markers, rbcL and tufA. Comparison of available CO1 and 16S sequences of specimens from various localities indicate a species complex with likely four distinct clades, but food analyses do not indicate an ecological separation of the investigated clades into differing foraging strategies. The combined results from both algal markers suggest that, in general, P. ocellatus has a broad food spectrum, including members of the genera Halimeda, Caulerpa, Udotea, Acetabularia and further unidentified algae, with an emphasis on H. macroloba. Independent of the duration of starvation and light exposure, this algal species and a further unidentified Halimeda species seem to be the main food source of P. ocellatus from the Philippines. It is shown here that at least two (or possibly three) barcode markers are required to cover the entire food spectrum in future analyses of Sacoglossa.

The intermediate wavelength magnetic anomaly field of the north Pacific and possible source distributions

NASA Technical Reports Server (NTRS)

Labrecque, J. L.; Cande, S. C.; Jarrard, R. D. (Principal Investigator)

1983-01-01

A technique that eliminates external field sources and the effects of strike aliasing was used to extract from marine survey data the intermediate wavelength magnetic anomaly field for (B) in the North Pacific. A strong correlation exists between this field and the MAGSAT field although a directional sensitivity in the MAGSAT field can be detected. The intermediate wavelength field is correlated to tectonic features. Island arcs appear as positive anomalies of induced origin likely due to variations in crustal thickness. Seamount chains and oceanic plateaus also are manifested by strong anomalies. The primary contribution to many of these anomalies appears to be due to a remanent magnetization. The source parameters for the remainder of these features are presently unidentified ambiguous. Results indicate that the sea surface field is a valuable source of information for secular variation analysis and the resolution of intermediate wavelength source parameters.

Gamma-ray emission from globular clusters. Shock high energy emission from the Be-Star/Pulsar System PSR 1259-63. Echoes in x-ray novae

NASA Technical Reports Server (NTRS)

Kaaret, Philip

1995-01-01

This grant covers work on the Compton phase 3 investigation, 'Shock High Energy Emission from the Be- Star/Pulsar System PSR 1259-63' and cycle 4 investigations 'Diffuse Gamma-Ray Emission at High Latitudes' and 'Echoes in X-Ray Novae'. Work under the investigation 'Diffuse Gamma-Ray Emission at High Latitudes' has lead to the publication of a paper (attached), describing gamma-ray emissivity variations in the northern galactic hemisphere. Using archival EGRET data, we have found a large irregular region of enhanced gamma-ray emissivity at energies greater 100 MeV. This is the first observation of local structure in the gamma-ray emissivity. Work under the investigation 'Echoes in X-Ray Novae' is proceeding with analysis of data from OSSE from the transient source GRO J1655-40. The outburst of this source last fall triggered this Target of Opportunity investigation. Preliminary spectral analysis shows emission out to 600 keV and a pure power low spectrum with no evidence of an exponential cutoff. Work is complete on the analysis of BATSE data from the Be-Star/Pulsar Sustem PSR 1259-63.

Parking lot sealcoat: An unrecognized source of urban polycyclic aromatic hydrocarbons

USGS Publications Warehouse

Mahler, B.J.; Van Metre, P.C.; Bashara, T.J.; Wilson, J.T.; Johns, D.A.

2005-01-01

Polycyclic aromatic hydrocarbons (PAHs) are a ubiquitous contaminant in urban environments. Although numerous sources of PAHs to urban runoff have been identified, their relative importance remains uncertain. We show that a previously unidentified source of urban PAHs, parking lot sealcoat, may dominate loading of PAHs to urban water bodies in the United States. Particles in runoff from parking lots with coal-tar emulsion sealcoat had mean concentrations of PAHs of 3500 mg/kg, 65 times higher than the mean concentration from unsealed asphalt and cement lots. Diagnostic ratios of individual PAHs indicating sources are similar for particles from coal-tar emulsion sealed lots and suspended sediment from four urban streams. Contaminant yields projected to the watershed scale for the four associated watersheds indicate that runoff from sealed parking lots could account for the majority of stream PAH loads.

IDENTIFICATION OF A POPULATION OF X-RAY-EMITTING MASSIVE STARS IN THE GALACTIC PLANE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, Gemma E.; Gaensler, B. M.; Kaplan, David L.

2011-02-01

We present X-ray, infrared, optical, and radio observations of four previously unidentified Galactic plane X-ray sources: AX J163252-4746, AX J184738-0156, AX J144701-5919, and AX J144547-5931. Detection of each source with the Chandra X-ray Observatory has provided sub-arcsecond localizations, which we use to identify bright infrared counterparts to all four objects. Infrared and optical spectroscopy of these counterparts demonstrate that all four X-ray sources are extremely massive stars, with spectral classifications: Ofpe/WN9 (AX J163252-4746), WN7 (AX J184738-0156 = WR121a), WN7-8h (AX J144701-5919), and OIf{sup +} (AX J144547-5931). AX J163252-4746 and AX J184738-0156 are both luminous, hard, X-ray emitters with strong Femore » XXV emission lines in their X-ray spectra at {approx}6.7 keV. The multi-wavelength properties of AX J163252-4746 and AX J184738-0156 are not consistent with isolated massive stars or accretion onto a compact companion; we conclude that their X-ray emission is most likely generated in a colliding-wind binary (CWB) system. For both AX J144701-5919 and AX J144547-5931, the X-ray emission is an order of magnitude less luminous and with a softer spectrum. These properties are consistent with a CWB interpretation for these two sources also, but other mechanisms for the generation of X-rays cannot be excluded. There are many other as yet unidentified X-ray sources in the Galactic plane, with X-ray properties similar to those seen for AX J163252-4746, AX J184738-0156, AX J144701-5919, and AX J144547-5931. This may indicate a substantial population of X-ray-emitting massive stars and CWBs in the Milky Way.« less

Forensic DNA typing from teeth using demineralized root tips.

PubMed

Corrêa, Heitor Simões Dutra; Pedro, Fabio Luis Miranda; Volpato, Luiz Evaristo Ricci; Pereira, Thiago Machado; Siebert Filho, Gilberto; Borges, Álvaro Henrique

2017-11-01

Teeth are widely used samples in forensic human genetic identification due to their persistence and practical sampling and processing. Their processing, however, has changed very little in the last 20 years, usually including powdering or pulverization of the tooth. The objective of this study was to present demineralized root tips as DNA sources while, at the same time, not involving powdering the samples or expensive equipment for teeth processing. One to five teeth from each of 20 unidentified human bodies recovered from midwest Brazil were analyzed. Whole teeth were demineralized in EDTA solution with daily solution change. After a maximum of approximately seven days, the final millimeters of the root tip was excised. This portion of the sample was used for DNA extraction through a conventional organic protocol. DNA quantification and STR amplification were performed using commercial kits followed by capillary electrophoresis on 3130 or 3500 genetic analyzers. For 60% of the unidentified bodies (12 of 20), a full genetic profile was obtained from the extraction of the first root tip. By the end of the analyses, full genetic profiles were obtained for 85% of the individuals studied, of which 80% were positively identified. This alternative low-tech approach for postmortem teeth processing is capable of extracting DNA in sufficient quantity and quality for forensic casework, showing that root tips are viable nuclear DNA sources even after demineralization. Copyright © 2017 Elsevier B.V. All rights reserved.

Discovery of a novel retrovirus sequence in an Australian native rodent (Melomys burtoni): a putative link between gibbon ape leukemia virus and koala retrovirus.

PubMed

Simmons, Greg; Clarke, Daniel; McKee, Jeff; Young, Paul; Meers, Joanne

2014-01-01

Gibbon ape leukaemia virus (GALV) and koala retrovirus (KoRV) share a remarkably close sequence identity despite the fact that they occur in distantly related mammals on different continents. It has previously been suggested that infection of their respective hosts may have occurred as a result of a species jump from another, as yet unidentified vertebrate host. To investigate possible sources of these retroviruses in the Australian context, DNA samples were obtained from 42 vertebrate species and screened using PCR in order to detect proviral sequences closely related to KoRV and GALV. Four proviral partial sequences totalling 2880 bases which share a strong similarity with KoRV and GALV were detected in DNA from a native Australian rodent, the grassland melomys, Melomys burtoni. We have designated this novel gammaretrovirus Melomys burtoni retrovirus (MbRV). The concatenated nucleotide sequence of MbRV shares 93% identity with the corresponding sequence from GALV-SEATO and 83% identity with KoRV. The geographic ranges of the grassland melomys and of the koala partially overlap. Thus a species jump by MbRV from melomys to koalas is conceivable. However the genus Melomys does not occur in mainland South East Asia and so it appears most likely that another as yet unidentified host was the source of GALV.

Use of stable carbon and nitrogen isotopes to trace the larval striped bass food chain in the Sacramento-San Joaquin Estuary, California, April to September 1985

USGS Publications Warehouse

Rast, Walter; Sutton, J.E.

1989-01-01

To assess one potential cause for the decline of the striped bass fishery in the Sacramento-San Joaquin Estuary, stable carbon and nitrogen isotope ratios were used to examine the trophic structures of the larval striped bass food chain, and to trace the flux of these elements through the food chain components. Study results generally confirm a food chain consisting of the elements, phytoplankton/detritus-->zooplankton/Neomysis shrimp-->larval striped bass. The stable isotope ratios generally become more positive as one progresses from the lower to the higher trophic level food chain components, and no unusual trophic structure was found in the food chain. However, the data indicate an unidentified consumer organism occupying an intermediate position between the lower and higher trophic levels of the larval striped bass food chain. Based on expected trophic interactions, this unidentified consumer would have a stable carbon isotope ratio of about 28/mil and a stable nitrogen isotope ratio of about 8/mi. Three possible feeding stages for larval striped bass also were identified, based on their lengths. The smallest length fish seem to subsist on their yolk sac remnants, and the largest length fish subsist on Neomysis shrimp and zooplankton. The intermediate-length fish represent a transition stage between primary food sources and/or use of a mixture of food sources. (USGS)

Aspidoscelis deppii (Black-bellied Racerunner). Predation by Great Egrets

USGS Publications Warehouse

Reynolds, Robert P.; Whatton, James F.; Gebhard, Christina A.

2014-01-01

Aspidoscelis deppii) is widely distributed from Veracruz and Michoacan, Mexico to Costa Rica (Köhler et al. 2006. The Amphibians and Reptiles of El Salvador. Krieger Publishing Co., Malabar, Florida. 238 pp.). Neotropical lizards are abundant and common prey to all classes of terrestrial vertebrates, and bird predation of lizards is well known.

Creative Photography - Wildlife

NASA Image and Video Library

2016-03-25

A snowy egret focuses its attention on a potential meal swimming in a shallow waterway at Merritt Island National Wildlife Refuge in Florida. NASA’s Kennedy Space Center shares boundaries with the refuge, which is home to more than 330 native and migratory bird species, along with 25 mammal, 117 fish, and 65 amphibian and reptile species.

Nature Photography - Birds

NASA Image and Video Library

2017-01-04

A snowy egret perches on a branch near a waterway at NASA's Kennedy Space Center in Florida. The center shares a border with the Merritt Island National Wildlife Refuge. The bird is one of more than 330 native and migratory bird species, 25 mammals, 117 fishes and 65 amphibians and reptiles that call Kennedy and the wildlife refuge home.

Nature Photography - Birds

NASA Image and Video Library

2016-12-12

A flock of egrets soars above the Skid Strip at Cape Canaveral Air Force Station, near NASA's Kennedy Space Center in Florida. The center shares a boundary with the Merritt Island National Wildlife Refuge. The refuge is home to more than 65 amphibian and reptile species, along with 330 native and migratory bird species, 25 mammal and 117 fish species.

Two Echinostome Species, Pegosomum bubulcum and Nephrostomum ramosum (Digenea: Echinostomatidae), from an Eastern Cattle Egret, Bubulcus ibis coromandus, in Republic of Korea

PubMed Central

Choe, Seongjun; Lee, Dongmin; Park, Hansol; Jeon, Hyeong-Kyu; Lee, Youngsun; Kim, Eunju; Na, Ki-Jeong; Eom, Keeseon S.

2016-01-01

We describe 2 echinostome species recovered from an Eastern cattle egret, Bubulcus ibis coromandus, from Cheongju-si (city), Chungcheongbuk-do (province), Korea. Total 72 Pegosomum bubulcum specimens were recovered from the bile duct. They were 7,566×2,938 μm in average size and had 27 collar spines with vitelline extension from anterior 1/3 level of the esophagus to mid-level of the posterior testis as characteristic features. Total 9 specimens of Nephrostomum ramosum were recovered in the small intestines of the bird. They were ribbon-shaped, 11,378×2,124 μm in average size, and morphologically variable in some organs, i.e., the number of collar spines (47-50), the shape of ovary and testes, and the extension of vitelline follicles. These morphological variations observed in a single host indicated that these features are not critical for the classification of Nephrostomum species and thus were reconsidered taxonomically as synonym of N. ramosum. This study is the first report documenting and describing both flukes and their associated genera in Korea. PMID:27658601

Two Echinostome Species, Pegosomum bubulcum and Nephrostomum ramosum (Digenea: Echinostomatidae), from an Eastern Cattle Egret, Bubulcus ibis coromandus, in Republic of Korea.

PubMed

Choe, Seongjun; Lee, Dongmin; Park, Hansol; Jeon, Hyeong-Kyu; Lee, Youngsun; Kim, Eunju; Na, Ki-Jeong; Eom, Keeseon S

2016-08-01

We describe 2 echinostome species recovered from an Eastern cattle egret, Bubulcus ibis coromandus, from Cheongju-si (city), Chungcheongbuk-do (province), Korea. Total 72 Pegosomum bubulcum specimens were recovered from the bile duct. They were 7,566×2,938 μm in average size and had 27 collar spines with vitelline extension from anterior 1/3 level of the esophagus to mid-level of the posterior testis as characteristic features. Total 9 specimens of Nephrostomum ramosum were recovered in the small intestines of the bird. They were ribbon-shaped, 11,378×2,124 μm in average size, and morphologically variable in some organs, i.e., the number of collar spines (47-50), the shape of ovary and testes, and the extension of vitelline follicles. These morphological variations observed in a single host indicated that these features are not critical for the classification of Nephrostomum species and thus were reconsidered taxonomically as synonym of N. ramosum. This study is the first report documenting and describing both flukes and their associated genera in Korea.

Shell thinning and pesticide residues in Texas aquatic bird eggs, 1970

USGS Publications Warehouse

King, K.A.; Flickinger, Edward L.; Hildebrand, H.H.

1978-01-01

Significant decreases in eggshell thickness were found in 15 of 22 species of aquatic birds in Texas in 1970. Shell thickness reductions of 9 to 15 percent were found in white pelicans (Pelecanus erythrorhynchos), brown pelicans (P .occidentalis), and great blue herons (Ardea herodias). DDT family compounds were found in all eggs, and mean residues ranged from 0.4 ppm in white ibis (Eudocimus albus) to 23.2 ppm in great egrets (Casmerodius albus). GDDT residues were negatively correlated with shell thickness in five species; PCBs were negatively correlated in two. Residues in marine birds were generally lower and more uniform than levels in birds feeding in fresh and brackish water. DDT and dieldrin residues were higher in eggs from colonies near agricultural areas where these insecticides were heavily used; higher PCB residues were consistently associated with urban and industrial areas. Populations of five species have declined and deserve continued study: brown pelican, reddish egret (Dichromanassa rufescens), white-faced ibis (Plegadis chihi), laughing gull (Larus atricilla), and Forster's tern (Sterna forsteri). Population trends of four other species were undetermined and should be followed closely in future years.

An investigation of the growing number of deaths of unidentified people in Russia

PubMed Central

Andreev, Evgueni; Pridemore, William Alex; Shkolnikov, Vladimir M.; Antonova, Olga I.

2008-01-01

Background We examined mortality among working-age Russian men whose identity could not be determined, focusing on where and how they died. Methods Employing micro-data from deaths that occurred in Izhevsk (Ural region) between June 2004 and September 2005, we analysed the characteristics of decedent men aged 25–54 (n= 2158). Differences between completely identified (n= 1699) and unidentified deaths (n= 282) were compared via logistic regression. Data on all deaths in Russia in 2002 were used for supplemental comparisons. Results We found that relative to identified men, unidentified men were at a higher risk of death from exposure to natural cold, violence, alcoholic cardiomyopathy, acute respiratory infections and poisonings. Our results also revealed that alcohol played an important role in the mortality of unidentified men. The places and causes of death among these unidentified men provide substantial evidence of their homelessness and social isolation. Conclusion The increase in deaths among unidentified men of working-age indicates the emergence of a health threat associated with homelessness and social marginalization. This vulnerable group is exposed to different levels and causes of mortality compared with the larger population and represent a new challenge that requires serious and immediate scholarly attention and policy responses. PMID:18160388

Rapid screening for human-pathogenic Mucorales using rolling circle amplification.

PubMed

Dolatabadi, S; Najafzadeh, M J; de Hoog, G S

2014-12-01

Mucormycosis has emerged as a relatively common severe mycosis in patients with haematological and allogeneic stem cell transplantation. Source of transmission is from unidentified sources in the environment. Early diagnosis of infection and its source of contamination are paramount for rapid and appropriate therapy. In this study, rolling circle amplification (RCA) is introduced as a sensitive, specific and reproducible isothermal DNA amplification technique for rapid molecular identification of six of the most virulent species (Rhizopus microsporus, R. arrhizus var. arrhizus, R. arrhizus var. delemar, Mucor irregularis, Mucor circinelloides, Lichtheimia ramosa, Lichtheimia corymbifera). DNAs of target species were successfully amplified, with no cross reactivity between species. RCA can be considered as a rapid detection method with high specificity and sensitivity, suitable for large screening. © 2014 Blackwell Verlag GmbH.

The first catalog of active galactic nuclei detected by the FERMI large area telescope

DOE PAGES

Abdo, A. A.; Ackermann, M.; Ajello, M.; ...

2010-04-29

Here, we present the first catalog of active galactic nuclei (AGNs) detected by the Large Area Telescope (LAT), corresponding to 11 months of data collected in scientific operation mode. The First LAT AGN Catalog (1LAC) includes 671 γ-ray sources located at high Galactic latitudes (|b|>10°) that are detected with a test statistic greater than 25 and associated statistically with AGNs. Some LAT sources are associated with multiple AGNs, and consequently, the catalog includes 709 AGNs, comprising 300 BL Lacertae objects, 296 flat-spectrum radio quasars, 41 AGNs of other types, and 72 AGNs of unknown type. We also classify the blazarsmore » based on their spectral energy distributions as archival radio, optical, and X-ray data permit. In addition to the formal 1LAC sample, we provide AGN associations for 51 low-latitude LAT sources and AGN "affiliations" (unquantified counterpart candidates) for 104 high-latitude LAT sources without AGN associations. The overlap of the 1LAC with existing γ-ray AGN catalogs (LBAS, EGRET, AGILE, Swift, INTEGRAL, TeVCat) is briefly discussed. Various properties—such as γ-ray fluxes and photon power-law spectral indices, redshifts, γ-ray luminosities, variability, and archival radio luminosities—and their correlations are presented and discussed for the different blazar classes. Lastly, we compare the 1LAC results with predictions regarding the γ-ray AGN populations, and we comment on the power of the sample to address the question of the blazar sequence.« less

Swift and GLAST Cooperative Efforts

NASA Technical Reports Server (NTRS)

Thompson, D. J.

2007-01-01

Because gamma-ray astrophysics depends in many ways on multiwavelength studies, the Gamma-ray Large Area Space Telescope (GLAST) instrument teams are eagerly anticipating coordinated observations with the Swift observatory. Swift and GLAST combined cover most of twelve orders of magnitude in the electromagnetic spectrum, offering numerous opportunities for cooperation. Three of the high-priority interests are: (1) gamma-ray burst studies; (2) broad-spectrum studies of blazars in both quiescent and flaring states; and (3) identification and detailed study of unidentified gamma-ray sources.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsia Chih-Hao; Sadjadi, Seyedabdolreza; Zhang Yong

An unidentified infrared emission (UIE) feature at 6.0 μ m is detected in a number of astronomical sources showing the UIE bands. In contrast to the previous suggestion that this band is due to C=O vibrational modes, we suggest that the 6.0 μ m feature arises from olefinic double-bond functional groups. These groups are likely to be attached to aromatic rings, which are responsible for the major UIE bands. The possibility that the formation of these functional groups is related to the hydrogenation process is discussed.

A search for TeV gamma-ray emission from SNRs, pulsars and unidentified GeV sources in the Galactic plane in the longitude range between -2 deg and 85 deg.

NASA Astrophysics Data System (ADS)

Aharonian, F. A.; Akhperjanian, A. G.; Beilicke, M.; Bernloehr, K.; Bojahr, H.; Bolz, O.; Boerst, H.; Coarasa, T.; Contreras, J. L.; Cortina, J.; Denninghoff, S.; Fonseca, V.; Girma, M.; Goetting, N.; Heinzelmann, G.; Hermann, G.; Heusler, A.; Hofmann, W.; Horns, D.; Jung, I.; Kankanyan, R.; Kestel, M.; Kettler, J.; Kohnle, A.; Konopelko, A.; Kornmeyer, H.; Kranich, D.; Krawczynski, H.; Lampeitl, H.; Lopez, M.; Lorenz, E.; Lucarelli, F.; Mang, O.; Meyer, H.; Mirzoyan, R.; Moralejo, A.; Ona, E.; Panter, M.; Plyasheshnikov, A.; Puehlhofer, G.; Rauterberg, G.; Reyes, R.; Rhode, W.; Ripken, J.; Roehring, A.; Rowell, G. P.; Sahakian, V.; Samorski, M.; Schilling, M.; Siems, M.; Sobzynska, D.; Stamm, W.; Tluczykont, M.; Voelk, H. J.; Wiedner, C. A.; Wittek, W.

2002-12-01

Using the HEGRA system of imaging atmospheric Cherenkov telescopes, one quarter of the Galactic plane (-2o < l < 85o) was surveyed for TeV gamma-ray emission from point sources and moderately extended sources (φ <= 0.8o). The region covered includes 86 known pulsars (PSR), 63 known supernova remnants (SNR) and nine GeV sources, representing a significant fraction of the known populations. No evidence for emission of TeV gamma radiation was detected, and upper limits range from 0.15 Crab units up to several Crab units, depending on the observation time and zenith angles covered. The ensemble sums over selected SNR and pulsar subsamples and over the GeV-sources yield no indication of emission from these potential sources. The upper limit for the SNR population is 6.7% of the Crab flux and for the pulsar ensemble is 3.6% of the Crab flux.

Exploring the High Energy Universe: GLAST Mission and Science

NASA Technical Reports Server (NTRS)

McEnery, Julie

2007-01-01

GLAST, the Gamma-Ray Large Area Space Telescope, is NASA's next-generation high-energy gamma-ray satellite scheduled for launch in Autumn 2007. GLAST will allow measurements of cosmic gamma-ray sources in the 10 MeV to 100 GeV energy band to be made with unprecedented sensitivity. Amongst its key scientific objectives are to understand particle acceleration in Active Galactic Nuclei, Pulsars and Supernovae Remnants, to provide high resolution measurements of unidentified gamma-ray sources, to study transient high energy emission from objects such as gamma-ray bursts, and to probe Dark Matter and the early Universe. Dr. McEnery will present an overview of the GLAST mission and its scientific goals.

Parking lot sealcoat: an unrecognized source of urban polycyclic aromatic hydrocarbons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barbara J. Mahler; Peter C. Van Metre; Thomas J. Bashara

2005-08-01

Polycyclic aromatic hydrocarbons (PAHs) are a ubiquitous contaminant in urban environments. Although numerous sources of PAHs to urban runoff have been identified, their relative importance remains uncertain. The authors show that a previously unidentified source of urban PAHs, parking lot sealcoat, may dominate loading of PAHs to urban water bodies in the United States. Particles in runoff from parking lots with coal-tar emulsion sealcoat had mean concentrations of PAHs of 3500 mg/kg, 65 times higher than the mean concentration from unsealed asphalt and cement lots. Diagnostic ratios of individual PAHs indicating sources are similar for particles from coal-tar emulsion sealedmore » lots and suspended sediment from four urban streams. Contaminant yields projected to the watershed scale for the four associated watersheds indicate that runoff from sealed parking lots could account for the majority of stream PAH loads. 35 refs., 6 figs., 2 tabs.« less

Optical Spectroscopic Survey of a Sample of Unidentified Fermi Objects

NASA Astrophysics Data System (ADS)

Paiano, Simona; Falomo, Renato; Franceschini, Alberto; Treves, Aldo; Scarpa, Riccardo

2017-12-01

We present optical spectroscopy secured at the 10 m Gran Telescopio Canarias of the counterparts of 20 extragalactic γ-ray sources detected by the Fermi satellite. The observations allow us to investigate the nature of these sources and to determine their redshift. We find that all optical counterparts have a spectrum that is consistent with a BL Lac object nature. We are able to determine the redshift for 11 objects and set spectroscopic redshift limits for five targets. The optical spectrum is found featureless for only four sources. In the latter cases, we can set lower limits on the redshift based on the assumption that they are hosted by a typical massive elliptical galaxy whose spectrum is diluted by the nonthermal continuum. The observations allow us to unveil the nature of these gamma-ray sources and provide a sanity check of a tool to discover the counterparts of γ-ray emitters/blazars based on their multiwavelength emission.

Blood meal analysis and virus detection in blood-fed mosquitoes collected during the 2006-2007 Rift Valley fever outbreak in Kenya.

PubMed

Lutomiah, Joel; Omondi, David; Masiga, Daniel; Mutai, Collins; Mireji, Paul O; Ongus, Juliette; Linthicum, Ken J; Sang, Rosemary

2014-09-01

Rift Valley fever (RVF) is a zoonosis of domestic ruminants in Africa. Blood-fed mosquitoes collected during the 2006-2007 RVF outbreak in Kenya were analyzed to determine the virus infection status and animal source of the blood meals. Blood meals from individual mosquito abdomens were screened for viruses using Vero cells and RT-PCR. DNA was also extracted and the cytochrome c oxidase 1 (CO1) and cytochrome b (cytb) genes amplified by PCR. Purified amplicons were sequenced and queried in GenBank and Barcode of Life Database (BOLD) to identify the putative blood meal sources. The predominant species in Garissa were Aedes ochraceus, (n=561, 76%) and Ae. mcintoshi, (n=176, 24%), and Mansonia uniformis, (n=24, 72.7%) in Baringo. Ae. ochraceus fed on goats (37.6%), cattle (16.4%), donkeys (10.7%), sheep (5.9%), and humans (5.3%). Ae. mcintoshi fed on the same animals in almost equal proportions. RVFV was isolated from Ae. ochraceus that had fed on sheep (4), goats (3), human (1), cattle (1), and unidentified host (1), with infection and dissemination rates of 1.8% (10/561) and 50% (5/10), respectively, and 0.56% (1/176) and 100% (1/1) in Ae. mcintoshi. In Baringo, Ma. uniformis fed on sheep (38%), frogs (13%), duikers (8%), cattle (4%), goats (4%), and unidentified hosts (29%), with infection and dissemination rates of 25% (6/24) and 83.3% (5/6), respectively. Ndumu virus (NDUV) was also isolated from Ae. ochraceus with infection and dissemination rates of 2.3% (13/561) and 76.9% (10/13), and Ae. mcintoshi, 2.8% (5/176) and 80% (4/5), respectively. Ten of the infected Ae. ochraceus had fed on goats, sheep (1), and unidentified hosts (2), and Ae. mcintoshi on goats (3), camel (1), and donkey (1). This study has demonstrated that RVFV and NDUV were concurrently circulating during the outbreak, and sheep and goats were the main amplifiers of these viruses respectively.

Optical photometric monitoring of gamma -ray loud blazars. II. Observations from November 1995 to June 1996

NASA Astrophysics Data System (ADS)

Raiteri, C. M.; Ghisellini, G.; Villata, M.; de Francesco, G.; Lanteri, L.; Chiaberge, M.; Peila, A.; Antico, G.

1998-02-01

New data from the optical monitoring of gamma -ray loud blazars at the Torino Astronomical Observatory are presented. Observations have been taken in the Johnson's B, V, and Cousins' R bands with the 1.05m REOSC telescope equipped with a 1242x1152 pixel CCD camera. Many of the 22 monitored sources presented here show noticeable magnitude variations. Periods corresponding to pointings of the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory (CGRO) satellite are indicated on the light curves. The comparison of our data with those taken by CGRO in the gamma -ray band will contribute to better understand the mechanism of the gamma -ray emission. We finally show intranight light curves of 3C 66A and OJ 287, where microvariability was detected. Tables 2--21 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html

Spectrum of the Isotropic Diffuse Gamma-Ray Emission Derived from First-Year Fermi Large Area Telescope Data

DOE PAGES

Abdo, A. A.

2010-03-08

Here, we report on the first Fermi Large Area Telescope (LAT) measurements of the so-called “extragalactic” diffuse γ -ray emission (EGB). This component of the diffuse γ -ray emission is generally considered to have an isotropic or nearly isotropic distribution on the sky with diverse contributions discussed in the literature. The derivation of the EGB is based on detailed modeling of the bright foreground diffuse Galactic γ -ray emission, the detected LAT sources, and the solar γ -ray emission. We also find the spectrum of the EGB is consistent with a power law with a differential spectral index γ =more » 2.41 ± 0.05 and intensity I ( > 100 MeV ) = ( 1.03 ± 0.17 ) × 10 - 5 cm -2 s - 1 sr - 1 , where the error is systematics dominated. The EGB spectrum, presented here, is featureless, less intense, and softer than that derived from EGRET data.« less

Very High Energy Gamma Ray Extension of GRO Observations

NASA Technical Reports Server (NTRS)

Weekes, Trevor C.

1994-01-01

The membership, progress, and invited talks, publications, and proceedings made by the Whipple Gamma Ray Collaboration is reported for june 1990 through May 1994. Progress was made in the following areas: the May 1994 Markarian Flare at Whipple and EGRET (Energetic Gamma Ray Experiment Telescope) energies; AGN's (Active Galactic Nuclei); bursts; supernova remnants; and simulations and energy spectra.

KSC-02pd0435

NASA Image and Video Library

2002-03-29

KENNEDY SPACE CENTER, FLA. -- A mixed group of water birds searches for food in a lake near Kennedy Space Center. Identified are a Great Egret (background, with yellow beak), White Ibis (far right and center, orange beak), and Roseate Spoonbills. All prefer marshes, mud flats, ponds, lagoons and tidal flats as habitat. They are frequently found in the warm, coastal areas of Florida

Very high gamma ray extension of GRO observations

NASA Astrophysics Data System (ADS)

Weekes, Trevor C.

1994-12-01

The membership, progress, and invited talks, publications, and proceedings made by the Whipple Gamma Ray Collaboration is reported for june 1990 through May 1994. Progress was made in the following areas: the May 1994 Markarian Flare at Whipple and EGRET (Energetic Gamma Ray Experiment Telescope) energies; AGN's (Active Galactic Nuclei); bursts; supernova remnants; and simulations and energy spectra.

Pulsar observations with the MAGIC Telescope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lopez, M.; Contreras, J. L.; Otte, N.

2007-07-12

Pulsars were detected by EGRET up to energies below 20 GeV. Observations at higher energies with ground-based experiments, including MAGIC, so far failed to detect pulsars, indicating a sharp cutoff of the pulsed emission. Here we present, in particular, the results of the search for very high {gamma}-ray emission from the pulsar PSR B1951+32.

Nature Photography - Birds

NASA Image and Video Library

2016-12-12

A flock of egrets touches down near the Skid Strip at Cape Canaveral Air Force Station, near NASA's Kennedy Space Center in Florida. The center shares a boundary with the Merritt Island National Wildlife Refuge. The refuge is home to more than 65 amphibian and reptile species, along with 330 native and migratory bird species, 25 mammal and 117 fish species.

77 FR 49793 - Ortho-Phthalaldehyde; Receipt of Application for Emergency Exemption, Solicitation of Public Comment

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-17

... parapaucimobilis, Stenotrophomonas maltophilia, Methylobacterium extorquens, and unidentified gram negative rods..., Stenotrophomonas maltophilia, Methylobacterium extorquens, and unidentified gram negative rods. Information in...

VLA observations of unidentified Leiden-Berkeley Deep-Survey sources - Luminosity and redshift dependence of spectral properties

NASA Technical Reports Server (NTRS)

Kapahi, Vijay K.; Kulkarni, Vasant K.

1990-01-01

VLA observations of a complete subset of the Leiden-Berkeley Deep Survey sources that have S(1.4 GHz) greater than 10 mJy and are not optically identified down to F=22 mag are reported. By comparing the spectral and structural properties of the sources with samples from the literature, an attempt was made to disentangle the luminosity and redshift dependence of the spectral indices of extended emission in radio galaxies and of the incidence of compact steep-spectrum sources. It is found that the fraction of compact sources among those with a steep spectrum is related primarily to redshift, being much larger at high redshifts for sources of similar radio luminosity. Only a weak and marginally significant dependence of spectral indices of the extended sources on luminosity and redshift is found in samples selected at 1.4 and 2.7 GHz. It is pointed out that the much stronger correlation of spectral indices with luminosity may be arising partly from spectral curvature, and partly due to the preferential inclusion of very steep-spectrum sources from high redshift in low-frequency surveys.

MULE SPINNING, LOCATION UNIDENTIFIED. PHOTOCOPY OF c. 1900 VIEW. From ...

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

MULE SPINNING, LOCATION UNIDENTIFIED. PHOTOCOPY OF c. 1900 VIEW. From the collection of Mr. George Durette, Photographer, Manchester, N. H. - Amoskeag Millyard, Canal Street, Manchester, Hillsborough County, NH

Observations on particulate organic nitrates and unidentified components of NO y

NASA Astrophysics Data System (ADS)

Nielsen, Torben; Egeløv, Axel H.; Granby, Kit; Skov, Henrik

A method to determine the total content of particulate organic nitrates (PON) has been developed and ambient air measurements of PON, NO, N02, HNO3, peroxyacetyl nitrate (PAN), peroxypropionyl nitrate (PPN), gas NOY and particulate inorganic nitrate have been performed in the spring and early summer at an agricultural site in Denmark and compared with measurements of ozone, H 2O 2, SO 2, formic acid, acetic acid and methane sulphonic acid. The gas NO y detector determines the sum NO + NO 2 + HNO 2 + HNO 3 + PAN + PPN + gas phase organic nitrates + 2 × N 2O 5 + NO 3. The content of residual gas NO y ( = gas NO y - NO - NO 2 - HNO 3 - PAN - PPN) was determined and a group of unidentified NO y compounds was found. The phenomenon was observed at a site with relatively high NO x/NO y ratios compared to previous observations in U.S.A. and Canada. The residual gas NO y made up 7 ± 6% of total NOY (total NO y = gas NO y + particulate inorganic nitrate). Residual gas NO y was much higher than the particulate fraction of organic nitrates (PON). PON was only 0.25 ± 0.11% of total NO y. Both residual gas NO y and particulate organic nitrates episodes occurred with elevated concentrations of photochemical oxidants in connection with high-pressure systems suggesting atmospheric processes being the major source. Clean marine air can be discarded as a source for PON and residual gas NO y.

The Arizona Radio Observatory 1 mm Spectral Survey of IRC +10216 and VY Canis Majoris (215-285 GHz)

NASA Astrophysics Data System (ADS)

Tenenbaum, E. D.; Dodd, J. L.; Milam, S. N.; Woolf, N. J.; Ziurys, L. M.

2010-10-01

A low noise (1σ rms ~ 3 mK) 1 mm spectral survey (214.5-285.5 GHz) of the oxygen-rich supergiant VY Canis Majoris and the carbon-rich asymptotic giant branch star IRC +10216 has been conducted using the Arizona Radio Observatory's 10 m Submillimeter Telescope. Here the complete data set is presented. This study, carried out with a new ALMA-type receiver, marks the first continuous band scan of an O-rich circumstellar envelope, and the most sensitive survey to date of IRC +10216. In VY CMa, 130 distinct molecular lines were detected, 14 of which cannot be identified; in IRC +10216, 717 lines were observed, with 126 features remaining unidentified. In the 1 mm bands of VY CMa and IRC +10216, emission is present from 18 and 32 different chemical compounds, respectively, with 10 species common to both sources. Many narrow emission lines were observed in both circumstellar shells, arising from vibrationally excited molecules and from refractory-containing species. Line profiles in VY CMa also exhibit a variety of different shapes, caused by the complex, asymmetric outflow of this object. The survey highlights the fact that C-rich and O-rich circumstellar envelopes are chemically interesting, and both are sources of new interstellar molecules. The high number of unidentified lines and the unreliable rest frequencies for known species such as NaCN indicate the need for additional laboratory spectroscopy studies.

The Arizona Radio Observatory 1 mm Spectral Survey of IRC (plus)10216 and VY Canis Majoris (215-285 GHz)

NASA Technical Reports Server (NTRS)

Tenenbaum, E. D.; Dodd, J. L.; Milam, S. N.; Woolf, N. J.; Ziurys, L. M.

2010-01-01

A low noise (1(sigma) rms approx. 3 mK) 1. nun spectral survey (214.5-285.5 GHz) of the oxygen-rich supergiant VY Canis Majoris and the carbon-rich asymptotic giant branch star IRC +10216 has been conducted using the Arizona Radio Observatory's 10 m Submillimeter Telescope. Here the complete data set is presented. This study, carried out with a new ALMA-type receiver, marks the first continuous band scan of an O-rich circumstellar envelope, and the most sensitive survey to date of IRC +10216. In VY CMa, 130 distinct molecular lines were detected, 14 of which cannot be identified; in IRC +10216, 717 lines were observed, with 126 features remaining unidentified. In the 1 mm bands of VY CMa and IRC +10216, emission is present from 18 and 32 different chemical compounds, respectively, with 10 species common to both sources. Many narrow emission lines were observed in both circumstellar shells, arising from vibrationally excited molecules and from refractory-containing species. Line profiles in VY CMa also exhibit a variety of different shapes, caused by the complex, asymmetric outflow of this object. The survey highlights the fact that C-rich and O-rich circumstellar envelopes are chemically interesting, and both are sources of new interstellar molecules. The high number of unidentified lines and the unreliable, rest frequencies for known species such as NaCN indicate the need for additional laboratory spectroscopy studies.

VizieR Online Data Catalog: Blazars with γ-ray counterparts. II. (Massaro+, 2013)

NASA Astrophysics Data System (ADS)

Massaro, F.; D'Abrusco, R.; Paggi, A.; Masetti, N.; Giroletti, M.; Tosti, G.; Smith, H. A.; Funk, S.

2013-06-01

Our primary sample of unidentified γ-ray sources (UGSs) consists of all the sources for which no counterpart was assigned at low energies in the 2FGL or in the 2LAC (Nolan et al. 2012, Cat. J/ApJS/199/31; Ackermann et al. 2011, Cat. J/ApJ/743/171, respectively), for a total of 590 γ-ray objects. We considered and analyzed independently two subsamples of UGSs, distinguishing the 299 Fermi sources without any γ-ray analysis flags from the other 291 objects that have a warning in their γ-ray detection. The complete description of our association procedure together with the estimates of its efficiency and its completeness can be found in D'Abrusco et al. (Paper I, 2013, Cat. J/ApJS/206,12). (9 data files).

Probing the X-ray Emission from the Massive Star Cluster Westerlund 2

NASA Astrophysics Data System (ADS)

Lopez, Laura

2017-09-01

We propose a 300 ks Chandra ACIS-I observation of the massive star cluster Westerlund 2 (Wd2). This region is teeming with high-energy emission from a variety of sources: colliding wind binaries, OB and Wolf-Rayet stars, two young pulsars, and an unidentified source of very high-energy (VHE) gamma-rays. Our Chandra program is designed to achieve several goals: 1) to take a complete census of Wd2 X-ray point sources and monitor variability; 2) to probe the conditions of the colliding winds in the binary WR 20a; 3) to search for an X-ray counterpart of the VHE gamma-rays; 4) to identify diffuse X-ray emission; 5) to compare results to other massive star clusters observed by Chandra. Only Chandra has the spatial resolution and sensitivity necessary for our proposed analyses.

Gamma-ray astronomy with muons: Sensitivity of IceCube to PeVatrons in the Southern sky

DOE Office of Scientific and Technical Information (OSTI.GOV)

Halzen, Francis; O'Murchadha, Aongus; Kappes, Alexander

2009-10-15

Northern hemisphere TeV gamma-ray observatories such as Milagro and Tibet AS{gamma} have demonstrated the importance of all-sky instruments by discovering previously unidentified sources that may be the PeVatrons producing cosmic rays up to the knee in the cosmic ray spectrum. We evaluate the potential of IceCube to identify similar sources in the southern sky by detailing an analytic approach to determine fluxes of muons from TeV gamma-ray showers. We apply this approach to known gamma-ray sources such as supernova remnants. We find that, similar to Milagro, detection is possible in 10 years for pointlike PeVatrons with fluxes stronger than severalmore » 10{sup -11} particles TeV{sup -1} cm{sup -2} s{sup -1}.« less

18. Photocopy of undated illustration in unidentified publication. CEILING AND ...

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

18. Photocopy of undated illustration in unidentified publication. CEILING AND REREDOS PRESERVED IN 1884 RESTORATION - Mission Santa Clara de Asis, Franklin & Grant Streets, Santa Clara, Santa Clara County, CA

AUTOCLASSIFICATION OF THE VARIABLE 3XMM SOURCES USING THE RANDOM FOREST MACHINE LEARNING ALGORITHM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farrell, Sean A.; Murphy, Tara; Lo, Kitty K., E-mail: s.farrell@physics.usyd.edu.au

In the current era of large surveys and massive data sets, autoclassification of astrophysical sources using intelligent algorithms is becoming increasingly important. In this paper we present the catalog of variable sources in the Third XMM-Newton Serendipitous Source catalog (3XMM) autoclassified using the Random Forest machine learning algorithm. We used a sample of manually classified variable sources from the second data release of the XMM-Newton catalogs (2XMMi-DR2) to train the classifier, obtaining an accuracy of ∼92%. We also evaluated the effectiveness of identifying spurious detections using a sample of spurious sources, achieving an accuracy of ∼95%. Manual investigation of amore » random sample of classified sources confirmed these accuracy levels and showed that the Random Forest machine learning algorithm is highly effective at automatically classifying 3XMM sources. Here we present the catalog of classified 3XMM variable sources. We also present three previously unidentified unusual sources that were flagged as outlier sources by the algorithm: a new candidate supergiant fast X-ray transient, a 400 s X-ray pulsar, and an eclipsing 5 hr binary system coincident with a known Cepheid.« less

Simulating deep surveys of the Galactic Plane with the Advanced Gamma-ray Imaging System (AGIS)

NASA Astrophysics Data System (ADS)

Funk, Stefan; Digel, Seth

2009-05-01

The pioneering survey of the Galactic plane by H.E.S.S., together with the northern complement now underway with VERITAS, has shown the inner Milky Way to be rich in TeV-emitting sources; new source classes have been found among the H.E.S.S. detections and unidentified sources remain. In order to explore optimizations of the design of an Advanced Gamma-ray Imaging System (AGIS)-like instrument for survey science, we constructed a model of the flux and size distributions of Galactic TeV sources, normalized to the H.E.S.S. sources but extrapolated to lower flux levels. We investigated potential outcomes from a survey with the order of magnitude improvement in sensitivity and attendant improvement in angular resolution planned for AGIS. Studies of individual sources and populations found with such a sensitivity survey will advance understanding of astrophysical particle acceleration, source populations, and even high-energy cosmic rays via detection of the low-level TeV diffuse emission in regions of high cosmic-ray densitiy.

High-resolution radio and X-ray observations of the supernova remnant W28

NASA Technical Reports Server (NTRS)

Andrews, M. D.; Basart, J. P.; Lamb, R. C.; Becker, R. H.

1983-01-01

The present study has the objective to report the first high resolution radio and X-ray observations of the central part of the galactic supernova remnant, W28, taking into account the possible association of the remnant with the unidentified gamma-ray source, 2CG 006-00. This gamma-ray source is approximately two-thirds as bright as the Crab pulsar above 100 MeV, and has a somewhat flatter spectrum. Both the radio and X-ray observations reveal previously unknown aspects of W28 which support the possibility of W28 being a gamma-ray source. The radio data show a flat-spectrum, nonthermal component reminiscent of the Crab Nebula and Vela, both of which are confirmed gamma-ray sources. The X-ray observations reveal a compact source within W28, again suggestive of both the Crab and Vela. If the similarities among W28, the Crab Nebula, and the Vela remnant are valid, the gamma-ray source 2CG 00-00 should be studied for periodicity, the conclusive signature of a compact source of emission.

Neural network classification of questionable EGRET events

NASA Astrophysics Data System (ADS)

Meetre, C. A.; Norris, J. P.

1992-02-01

High energy gamma rays (greater than 20 MeV) pair producing in the spark chamber of the Energetic Gamma Ray Telescope Experiment (EGRET) give rise to a characteristic but highly variable 3-D locus of spark sites, which must be processed to decide whether the event is to be included in the database. A significant fraction (about 15 percent or 104 events/day) of the candidate events cannot be categorized (accept/reject) by an automated rule-based procedure; they are therefore tagged, and must be examined and classified manually by a team of expert analysts. We describe a feedforward, back-propagation neural network approach to the classification of the questionable events. The algorithm computes a set of coefficients using representative exemplars drawn from the preclassified set of questionable events. These coefficients map a given input event into a decision vector that, ideally, describes the correct disposition of the event. The net's accuracy is then tested using a different subset of preclassified events. Preliminary results demonstrate the net's ability to correctly classify a large proportion of the events for some categories of questionables. Current work includes the use of much larger training sets to improve the accuracy of the net.

Assessing relationships between cattle egret migration and meteorology in the southwest Pacific: a review

NASA Astrophysics Data System (ADS)

Bridgman, H. A.; Maddock, M.; Geering, D. J.

The evolution of research into meteorological factors affecting the migration of the Cattle Egret (Ardeola ibis coromandus) in the southwestern Pacific region (Australia, New Zealand and the Tasman Sea) - from ground-based studies dependent on volunteer observers to a pilot satellite-tracking project - is reviewed and the results are related to the literature on bird migration. The predominant pattern is a seasonal migration from breeding colonies in southeast Queensland and northern New South Wales which takes place in stages along the east coastal plain under favourable meteorological conditions. Migration outward (southward) occurs in February through April and return to the breeding colonies occurs in October and November. Wintering destinations include Tasmania, southern Victoria and parts of New Zealand. Favourable meteorological conditions for migration southward include:moderate north to northwest airflow behind a high; light and variable winds in a high or col; and light and variable winds over New South Wales with moderate westerlies over Victoria and Tasmania. A satellite-tracking project helped to validate findings from the ground-based studies, provided additional information not otherwise obtainable, and demonstrated the potential of the technique to further clarify the relation between timing and staging of migration, and meteorology.

European solvent industry group generic exposure scenario risk and exposure tool

PubMed Central

Zaleski, Rosemary T; Qian, Hua; Zelenka, Michael P; George-Ares, Anita; Money, Chris

2014-01-01

The European Solvents Industry Group (ESIG) Generic Exposure Scenario (GES) Risk and Exposure Tool (EGRET) was developed to facilitate the safety evaluation of consumer uses of solvents, as required by the European Union Registration, Evaluation and Authorization of Chemicals (REACH) Regulation. This exposure-based risk assessment tool provides estimates of both exposure and risk characterization ratios for consumer uses. It builds upon the consumer portion of the European Center for Ecotoxicology and Toxicology of Chemicals (ECETOC) Targeted Risk Assessment (TRA) tool by implementing refinements described in ECETOC TR107. Technical enhancements included the use of additional data to refine scenario defaults and the ability to include additional parameters in exposure calculations. Scenarios were also added to cover all frequently encountered consumer uses of solvents. The TRA tool structure was modified to automatically determine conditions necessary for safe use. EGRET reports results using specific standard phrases in a format consistent with REACH exposure scenario guidance, in order that the outputs can be readily assimilated within safety data sheets and similar information technology systems. Evaluation of tool predictions for a range of commonly encountered consumer uses of solvents found it provides reasonable yet still conservative exposure estimates. PMID:23361440

Implications of the IRAS data for galactic gamma ray astronomy and EGRET

NASA Technical Reports Server (NTRS)

Stecker, Floyd W.

1990-01-01

Using the results of gamma-ray, millimeter wave and far surveys of the galaxy, logically consistent picture of the large scale distribution of galactic gas and cosmic rays was derived, tied to the overall processes of stellar birth and destruction on a galactic scale. Using the results of the IRAS far-infrared survey of te galaxy, the large scale radial distributions of galactic far-infrared emission independently was obtained for both the Northern and Southern Hemisphere sides of the Galaxy. The dominant feature in these distributions was found to be a broad peak coincident with the 5 kpc molecular gas cloud ring. Evidence was found for spiral arm features. Strong correlations are evident between the large scale galactic distributions of far-infrared emission, gamma-ray emission and total CO emission. There is particularly tight correlation between the distribution of warm molecular clouds and far-infrared emission on a galactic scale. The 5 kpc ring was evident in existing galactic gamma-ray data. The extent to which the more detailed spiral arm features are evident in the more resolved EGRET (Energetic Gamma-Ray Experimental Telescope) data will help to determine more precisely the propagation characteristics of cosmic rays.

European solvent industry group generic exposure scenario risk and exposure tool.

PubMed

Zaleski, Rosemary T; Qian, Hua; Zelenka, Michael P; George-Ares, Anita; Money, Chris

2014-01-01

The European Solvents Industry Group (ESIG) Generic Exposure Scenario (GES) Risk and Exposure Tool (EGRET) was developed to facilitate the safety evaluation of consumer uses of solvents, as required by the European Union Registration, Evaluation and Authorization of Chemicals (REACH) Regulation. This exposure-based risk assessment tool provides estimates of both exposure and risk characterization ratios for consumer uses. It builds upon the consumer portion of the European Center for Ecotoxicology and Toxicology of Chemicals (ECETOC) Targeted Risk Assessment (TRA) tool by implementing refinements described in ECETOC TR107. Technical enhancements included the use of additional data to refine scenario defaults and the ability to include additional parameters in exposure calculations. Scenarios were also added to cover all frequently encountered consumer uses of solvents. The TRA tool structure was modified to automatically determine conditions necessary for safe use. EGRET reports results using specific standard phrases in a format consistent with REACH exposure scenario guidance, in order that the outputs can be readily assimilated within safety data sheets and similar information technology systems. Evaluation of tool predictions for a range of commonly encountered consumer uses of solvents found it provides reasonable yet still conservative exposure estimates.

Neural network classification of questionable EGRET events

NASA Technical Reports Server (NTRS)

Meetre, C. A.; Norris, J. P.

1992-01-01

High energy gamma rays (greater than 20 MeV) pair producing in the spark chamber of the Energetic Gamma Ray Telescope Experiment (EGRET) give rise to a characteristic but highly variable 3-D locus of spark sites, which must be processed to decide whether the event is to be included in the database. A significant fraction (about 15 percent or 10(exp 4) events/day) of the candidate events cannot be categorized (accept/reject) by an automated rule-based procedure; they are therefore tagged, and must be examined and classified manually by a team of expert analysts. We describe a feedforward, back-propagation neural network approach to the classification of the questionable events. The algorithm computes a set of coefficients using representative exemplars drawn from the preclassified set of questionable events. These coefficients map a given input event into a decision vector that, ideally, describes the correct disposition of the event. The net's accuracy is then tested using a different subset of preclassified events. Preliminary results demonstrate the net's ability to correctly classify a large proportion of the events for some categories of questionables. Current work includes the use of much larger training sets to improve the accuracy of the net.

Observations of Spin-Powered Pulsars with the AGILE Gamma-Ray Telescope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pellizzoni, A.; Pilia, M.; Possenti, M.

2008-12-24

AGILE is a small gamma-ray astronomy satellite mission of the Italian Space Agency dedicated to high-energy astrophysics launched in 2007 April. It provides large sky exposure levels (> or approx. 10{sup 9} cm{sup 2} s per year on the Galactic Plane) with sensitivity peaking at E{approx}400 MeV(and simultaneous X-ray monitoring in the 18-60 keV band) where the bulk of pulsar energy output is typically released. Its {approx}1 {mu}s is absolute time tagging capability makes it perfectly suited for the study of gamma-ray pulsars following up on the CGRO/EGRET heritage. In this paper we summarize the timing results obtained during themore » first year of AGILE observations of the known gamma-ray pulsars Vela, Crab, Geminga and B 1706-4. AGILE collected a large number of gamma-ray photons from EGRET pulsars ({approx}10,000 pulsed counts for Vela) in only few months of observations unveiling new interesting features at sub-millisecond level in the pulsars' high-energy light-curves and paving the way to the discovery of new gamma-ray pulsars.« less

CORLISS ENGINE WITH DYNAMO AND ROPE DRIVE. LOCATION UNIDENTIFIED. PHOTOCOPY ...

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

CORLISS ENGINE WITH DYNAMO AND ROPE DRIVE. LOCATION UNIDENTIFIED. PHOTOCOPY OF c. 1900 VIEW. From the collection of the Manchester Historic Association, Manchester, N. H. - Amoskeag Millyard, Canal Street, Manchester, Hillsborough County, NH

Exploring the High Energy Universe: GLAST Mission and Science

NASA Technical Reports Server (NTRS)

McEnery, Julie

2007-01-01

GLAST, the Gamma-Ray Large Area Space Telescope, is NASA's next-generation high-energy gamma-ray satellite scheduled for launch in Autumn 2007. GLAST will allow measurements of cosmic gamma-ray sources in t he 10 MeV to 100 GeV energy band to be made with unprecedented sensi tivity. Amongst its key scientific objectives are to understand part icle acceleration in Active Galactic Nuclei, Pulsars and Supernovae Remnants, to provide high resolution measurements of unidentified ga mma-ray sources, to study transient high energy emission from objects such as gamma-ray bursts, and to probe Dark Matter and the early Uni verse. Dr. McEnery will present an overview of the GLAST mission and its scientific goals.

FERMI LARGE AREA TELESCOPE VIEW OF THE CORE OF THE RADIO GALAXY CENTAURUS A

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdo, A. A.; Ackermann, M.; Ajello, M.

2010-08-20

We present {gamma}-ray observations with the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope of the nearby radio galaxy Centaurus A (Cen A). The previous EGRET detection is confirmed, and the localization is improved using data from the first 10 months of Fermi science operation. In previous work, we presented the detection of the lobes by the LAT; in this work, we concentrate on the {gamma}-ray core of Cen A. Flux levels as seen by the LAT are not significantly different from that found by EGRET, nor is the extremely soft LAT spectrum ({Gamma} = 2.67 {+-}more » 0.10{sub stat} {+-} 0.08{sub sys} where the photon flux is {Phi} {proportional_to} E {sup -{Gamma}}). The LAT core spectrum, extrapolated to higher energies, is marginally consistent with the non-simultaneous HESS spectrum of the source. The LAT observations are complemented by simultaneous observations from Suzaku, the Swift Burst Alert Telescope and X-ray Telescope, and radio observations with the Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry program, along with a variety of non-simultaneous archival data from a variety of instruments and wavelengths to produce a spectral energy distribution (SED). We fit this broadband data set with a single-zone synchrotron/synchrotron self-Compton model, which describes the radio through GeV emission well, but fails to account for the non-simultaneous higher energy TeV emission observed by HESS from 2004 to 2008. The fit requires a low Doppler factor, in contrast to BL Lac objects which generally require larger values to fit their broadband SEDs. This indicates that the {gamma}-ray emission originates from a slower region than that from BL Lac objects, consistent with previous modeling results from Cen A. This slower region could be a slower moving layer around a fast spine, or a slower region farther out from the black hole in a decelerating flow. The fit parameters are also consistent with Cen A being able to accelerate ultra-high energy cosmic-rays, as hinted at by results from the Auger observatory.« less

Fermi Large Area Telescope View of the Core of the Radio Galaxy Centaurus A

NASA Astrophysics Data System (ADS)

Abdo, A. A.; Ackermann, M.; Ajello, M.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bouvier, A.; Brandt, T. J.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Cannon, A.; Caraveo, P. A.; Carrigan, S.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Çelik, Ö.; Charles, E.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Colafrancesco, S.; Cominsky, L. R.; Conrad, J.; Costamante, L.; Davis, D. S.; Dermer, C. D.; de Angelis, A.; de Palma, F.; Silva, E. do Couto e.; Drell, P. S.; Dubois, R.; Dumora, D.; Falcone, A.; Farnier, C.; Favuzzi, C.; Fegan, S. J.; Finke, J.; Focke, W. B.; Fortin, P.; Frailis, M.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Georganopoulos, M.; Germani, S.; Giebels, B.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grandi, P.; Grenier, I. A.; Grondin, M.-H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hadasch, D.; Harding, A. K.; Hase, Hayo; Hayashida, M.; Hays, E.; Horan, D.; Hughes, R. E.; Itoh, R.; Jackson, M. S.; Jóhannesson, G.; Johnson, A. S.; Johnson, T. J.; Johnson, W. N.; Kadler, M.; Kamae, T.; Katagiri, H.; Kataoka, J.; Kawai, N.; Kishishita, T.; Knödlseder, J.; Kuss, M.; Lande, J.; Latronico, L.; Lee, S.-H.; Lemoine-Goumard, M.; Llena Garde, M.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Makeev, A.; Mazziotta, M. N.; McConville, W.; McEnery, J. E.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Müller, C.; Nakamori, T.; Naumann-Godo, M.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohno, M.; Ohsugi, T.; Ojha, R.; Okumura, A.; Omodei, N.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Pagani, C.; Paneque, D.; Panetta, J. H.; Parent, D.; Pelassa, V.; Pepe, M.; Pesce-Rollins, M.; Piron, F.; Plötz, C.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Reposeur, T.; Ripken, J.; Ritz, S.; Rodriguez, A. Y.; Roth, M.; Ryde, F.; Sadrozinski, H. F.-W.; Sanchez, D.; Sander, A.; Scargle, J. D.; Sgrò, C.; Siskind, E. J.; Smith, P. D.; Spandre, G.; Spinelli, P.; Starck, J.-L.; Stawarz, L.; Strickman, M. S.; Suson, D. J.; Tajima, H.; Takahashi, H.; Takahashi, T.; Tanaka, T.; Thayer, J. B.; Thayer, J. G.; Thompson, D. J.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Tramacere, A.; Uchiyama, Y.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vilchez, N.; Vitale, V.; Waite, A. P.; Wang, P.; Winer, B. L.; Wood, K. S.; Yang, Z.; Ylinen, T.; Ziegler, M.

2010-08-01

We present γ-ray observations with the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope of the nearby radio galaxy Centaurus A (Cen A). The previous EGRET detection is confirmed, and the localization is improved using data from the first 10 months of Fermi science operation. In previous work, we presented the detection of the lobes by the LAT; in this work, we concentrate on the γ-ray core of Cen A. Flux levels as seen by the LAT are not significantly different from that found by EGRET, nor is the extremely soft LAT spectrum (Γ = 2.67 ± 0.10stat ± 0.08sys where the photon flux is Φ vprop E -Γ). The LAT core spectrum, extrapolated to higher energies, is marginally consistent with the non-simultaneous HESS spectrum of the source. The LAT observations are complemented by simultaneous observations from Suzaku, the Swift Burst Alert Telescope and X-ray Telescope, and radio observations with the Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry program, along with a variety of non-simultaneous archival data from a variety of instruments and wavelengths to produce a spectral energy distribution (SED). We fit this broadband data set with a single-zone synchrotron/synchrotron self-Compton model, which describes the radio through GeV emission well, but fails to account for the non-simultaneous higher energy TeV emission observed by HESS from 2004 to 2008. The fit requires a low Doppler factor, in contrast to BL Lac objects which generally require larger values to fit their broadband SEDs. This indicates that the γ-ray emission originates from a slower region than that from BL Lac objects, consistent with previous modeling results from Cen A. This slower region could be a slower moving layer around a fast spine, or a slower region farther out from the black hole in a decelerating flow. The fit parameters are also consistent with Cen A being able to accelerate ultra-high energy cosmic-rays, as hinted at by results from the Auger observatory.

FERMI Large Area Telescope View of the 1 Core of the Radio Galaxy Centaurus A

DOE PAGES

Abdo, A. A.; Ackermann, M.; Ajello, M.; ...

2010-07-29

We present γ-ray observations with the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope of the nearby radio galaxy Centaurus A (Cen A). The previous EGRET detection is confirmed, and the localization is improved using data from the first 10 months of Fermi science operation. In previous work, we presented the detection of the lobes by the LAT; in this work, we concentrate on the γ-ray core of Cen A. Flux levels as seen by the LAT are not significantly different from that found by EGRET, nor is the extremely soft LAT spectrum (Γ = 2.67 ±more » 0.10 stat ± 0.08 sys where the photon flux is Φ ∝ E –Γ). The LAT core spectrum, extrapolated to higher energies, is marginally consistent with the non-simultaneous HESS spectrum of the source. The LAT observations are complemented by simultaneous observations from Suzaku, the Swift Burst Alert Telescope and X-ray Telescope, and radio observations with the Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry program, along with a variety of non-simultaneous archival data from a variety of instruments and wavelengths to produce a spectral energy distribution (SED). Here, we fit this broadband data set with a single-zone synchrotron/synchrotron self-Compton model, which describes the radio through GeV emission well, but fails to account for the non-simultaneous higher energy TeV emission observed by HESS from 2004 to 2008. The fit requires a low Doppler factor, in contrast to BL Lac objects which generally require larger values to fit their broadband SEDs. This indicates that the γ-ray emission originates from a slower region than that from BL Lac objects, consistent with previous modeling results from Cen A. This slower region could be a slower moving layer around a fast spine, or a slower region farther out from the black hole in a decelerating flow. The fit parameters are also consistent with Cen A being able to accelerate ultra-high energy cosmic-rays, as hinted at by results from the Auger observatory.« less

LS 5039 - the counterpart of the unidentified MeV source GRO J1823-12

NASA Astrophysics Data System (ADS)

Collmar, W.; Zhang, S.

2014-05-01

Context. The COMPTEL experiment on CGRO observed the γ-ray sky at energies from 0.75 MeV to 30 MeV between April 1991 and June 2000. COMPTEL detected many γ-ray sources, among them an unidentified one labeled GRO J1823-12. It is located near l/b = 17.5°/-0.5° and positionally consistent with the prominent γ-ray binary LS 5039. Aims: LS 5039 was established as a γ-ray source at TeV energies by HESS and at GeV energies by Fermi/LAT during recent years, whose γ-ray radiation is modulated along its binary orbit. Given this new information we reanalyzed the COMPTEL data of GRO J1823-12 including an orbital-resolved analysis. Methods: We applied the standard methods, proper event selections and data binning with subsequent maximum-likelihood deconvolution, to analyze the COMPTEL data. In addition we developed a tool for selecting and binning the COMPTEL data in a phase-resolved manner. We present the orbit-averaged, as well as orbit-resolved MeV analyses, light curves, and spectra, and put them into a multifrequency context. Results: The COMPTEL data show a significant MeV source, which is positionally consistent with LS 5039, but also with other closeby Fermi/LAT sources. The orbit-resolved analysis provides strong evidence, at about the 3σ level, that the MeV flux of GRO J1823-12 is modulated along the binary orbit of about 3.9 days of LS 5039. We show that at MeV energies, the source is brighter at the orbital part around the inferior conjunction than at the part of the superior conjunction, so it is in phase with X-rays and TeV γ-rays, but in anti-phase with GeV γ-rays. The high-energy spectral energy distribution (X-rays to TeV γ-rays) shows the high-energy emission maximum of LS 5039 at MeV energies. Conclusions: We conclude that the COMPTEL source GRO J1823-12 is the counterpart of the microquasar LS 5039, at least for the majority of its MeV emission. The COMPTEL fluxes, put into multifrequency perspective, provide new constraints on the modeling of the high-energy emission pattern of the γ-ray binary LS 5039. Table 1 is available in electronic form at http://www.aanda.org

Clostridium pabulibutyricum sp. nov., a butyric-acid-producing organism isolated from high-moisture grass silage.

PubMed

Kobayashi, Hisami; Nakasato, Takuya; Sakamoto, Mitsuo; Ohtani, Yoshihisa; Terada, Fuminori; Sakai, Ken; Ohkuma, Moriya; Tohno, Masanori

2017-12-01

A Gram-stain-variable, strictly anaerobic, rod-shaped, catalase-negative and endospore-forming bacterial strain, designated MJC39 T , was isolated from grass silage preserved in Hokkaido, Japan. Growth occurred at 20-42 °C, pH 5.0-7.0 and NaCl concentrations up to 2 % (w/v). The isolated strain MJC39 T produced butyric acid in peptone yeast extract medium with glucose. The DNA G+C content of strain MJC39 T was 34.4±0.2 mol%. The major cellular fatty acids (>10 %) were C14 : 0, C16 : 0 and summed feature 3 (including C16 : 1ω7c/C16 : 1ω6c). No respiratory quinones were detected. The polar lipids of strain MJC39 T were phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, one unidentified lipid, one unidentified aminolipid, two unidentified glycolipids, one unidentified phospholipid, one unidentified aminoglycolipid and one unidentified phosphoaminoglycolipid. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain MJC39 T was a member of the genus Clostridium and is closely related to Clostridium tyrobutyricum JCM 11008 T (95.8 % similarity) and Clostridium algifaecis MB9-7 T (95.5 % similarity). Based on the genotypic, phenotypic and chemotaxonomic characteristics, strain MJC39 T represents a novel species of the genus Clostridium, for which the name Clostridium pabulibutyricum sp. nov. is proposed. The type strain is MJC39 T (=JCM 31506 T =DSM 103944 T ).

Six New Millisecond Pulsars From Arecibo Searches Of Fermi Gamma-Ray Sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cromartie, H. T.; Camilo, F.; Kerr, M.

2016-02-25

We have discovered six radio millisecond pulsars (MSPs) in a search with the Arecibo telescope of 34 unidentified gamma-ray sources from the Fermi Large Area Telescope (LAT) 4-year point source catalog. Among the 34 sources, we also detected two MSPs previously discovered elsewhere. Each source was observed at a center frequency of 327 MHz, typically at three epochs with individual integration times of 15 minutes. The new MSP spin periods range from 1.99 to 4.66 ms. Five of the six pulsars are in interacting compact binaries (period ≤ 8.1 hr), while the sixth is a more typical neutron star-white dwarfmore » binary with an 83-day orbital period. This is a higher proportion of interacting binaries than for equivalent Fermi-LAT searches elsewhere. The reason is that Arecibo’s large gain afforded us the opportunity to limit integration times to 15 minutes, which significantly increased our sensitivity to these highly accelerated systems. Seventeen of the remaining 26 gamma-ray sources are still categorized as strong MSP candidates, and will be re-searched.« less

SIX NEW MILLISECOND PULSARS FROM ARECIBO SEARCHES OF FERMI GAMMA-RAY SOURCES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cromartie, H. T.; Camilo, F.; Kerr, M.

2016-03-01

We have discovered six radio millisecond pulsars (MSPs) in a search with the Arecibo telescope of 34 unidentified gamma-ray sources from the Fermi Large Area Telescope (LAT) four year point source catalog. Among the 34 sources, we also detected two MSPs previously discovered elsewhere. Each source was observed at a center frequency of 327 MHz, typically at three epochs with individual integration times of 15 minutes. The new MSP spin periods range from 1.99 to 4.66 ms. Five of the six pulsars are in interacting compact binaries (period ≤ 8.1 hr), while the sixth is a more typical neutron star-whitemore » dwarf binary with an 83 day orbital period. This is a higher proportion of interacting binaries than for equivalent Fermi-LAT searches elsewhere. The reason is that Arecibo's large gain afforded us the opportunity to limit integration times to 15 minutes, which significantly increased our sensitivity to these highly accelerated systems. Seventeen of the remaining 26 gamma-ray sources are still categorized as strong MSP candidates, and will be re-searched.« less

Utilization of Dimethyl Sulfide as a Sulfur Source with the Aid of Light by Marinobacterium sp. Strain DMS-S1

PubMed Central

Fuse, Hiroyuki; Takimura, Osamu; Murakami, Katsuji; Yamaoka, Yukiho; Omori, Toshio

2000-01-01

Strain DMS-S1 isolated from seawater was able to utilize dimethyl sulfide (DMS) as a sulfur source only in the presence of light in a sulfur-lacking medium. Phylogenetic analysis based on 16S ribosomal DNA genes indicated that the strain was closely related to Marinobacterium georgiense. The strain produced dimethyl sulfoxide (DMSO), which was a main metabolite, and small amounts of formate and formaldehyde when grown on DMS as the sole sulfur source. The cells of the strain grown with succinate as a carbon source were able to use methyl mercaptan or methanesulfonate besides DMS but not DMSO or dimethyl sulfone as a sole sulfur source. DMS was transformed to DMSO primarily at wavelengths between 380 and 480 nm by heat-stable photosensitizers released by the strain. DMS was also degraded to formaldehyde in the presence of light by unidentified heat-stable factors released by the strain, and it appeared that strain DMS-S1 used the degradation products, which should be sulfite, sulfate, or methanesulfonate, as sulfur sources. PMID:11097944

Endocrine active chemicals and endocrine disruption in Minnesota streams and lakes: implications for aquatic resources, 1994-2008

USGS Publications Warehouse

Lee, Kathy E.; Schoenfuss, Heiko L.; Barber, Larry B.; Writer, Jeff H.; Blazer, Vicki; Keisling, Richard L.; Ferrey, Mark L.

2010-01-01

Although these studies indicate that wastewater-treatment plant effluent is a conduit for endocrine active chemicals to surface waters, endocrine active chemicals also were present in surface waters with no obvious wastewater-treatment plant effluent sources. Endocrine active chemicals were detected and indicators of endocrine disruption in fish were measured at numerous sites upstream from discharge of wastewater-treatment plant effluent. These observations indicate that other unidentified sources of endocrine active chemicals exist, such as runoff from land surfaces, atmospheric deposition, inputs from onsite septic systems, or other groundwater sources. Alternatively, some endocrine active chemicals may not yet have been identified or measured. The presence of biological indicators of endocrine disruption in male fish indicates that the fish are exposed to endocrine active chemicals. However indicators of endocrine disruption in male fish does not indicate an effect on fish reproduction or changes in fish populations.

Exploring the nature of the unidentified very-high-energy gamma-ray source HESS J1507-622

NASA Astrophysics Data System (ADS)

Domainko, W.; Ohm, S.

2012-09-01

Context. Several extended sources of very-high-energy (VHE; E > 100 GeV) gamma rays have been found that lack counterparts belonging to an established class of VHE gamma-ray emitters. Aims: The nature of the first unidentified VHE gamma-ray source with significant angular offset from the Galactic plane of 3.5°, HESS J1507-622, is explored. Methods.Fermi-LAT data in the high-energy (HE, 100 MeV < E < 100 GeV) gamma-ray range collected over 34 month are used to describe the spectral energy distribution (SED) of the source. Additionally, implications of the off-plane location of the source for a leptonic and hadronic gamma-ray emission model are investigated. Results: HESS J1507-622 is detected in the Fermi energy range and its spectrum is best described by a power law in energy with Γ = 1.7 ± 0.1stat ± 0.2sys and integral flux between (0.3-300) GeV of F = (2.0 ± 0.5stat ± 1.0sys) × 10-9 cm-2 s-1. The SED constructed from the Fermi and H.E.S.S. data for this source does not support a smooth power-law continuation from the VHE to the HE gamma-ray range. With the available data it is not possible to discriminate between a hadronic and a leptonic scenario for HESS J1507-622. The location and compactness of the source indicate a considerable physical offset from the Galactic plane for this object. In case of a multiple-kpc distance, this challenges a pulsar wind nebula (PWN) origin for HESS J1507-622 since the time of travel for a pulsar born in the Galactic disk to reach such a location would exceed the inverse Compton (IC) cooling time of electrons that are energetic enough to produce VHE gamma-rays. However, an origin of this gamma-ray source connected to a pulsar that was born off the Galactic plane in the explosion of a hypervelocity star cannot be excluded. Conclusions: The nature of HESS J1507-622 is still unknown to date, and a PWN scenario cannot be ruled out in general. On the contrary HESS J1507-622 could be the first discovered representative of a population of spatially extended VHE gamma-ray emitters with HE gamma-ray counterpart that are located at considerable offsets from the Galactic plane. Future surveys in the VHE gamma-ray range are necessary to probe the presence or absence of such a source population.

Characterization and zoonotic impact of Shiga toxin producing Escherichia coli in some wild bird species

PubMed Central

Fadel, Hanaa Mohamed; Afifi, Rabab; Al-Qabili, Dheyazan Mohammed

2017-01-01

Aim: Wild birds are considered silent vectors of some zoonotic water and food borne pathogens of public health significance. Owing to the importance of Shiga toxin producing Escherichia coli (STEC) as the most pathogenic among the emerging diarrheagenic E. coli groups that can infect man; the present study was designed to detect the occurrence of STEC among wild birds in Egypt. Materials and Methods: A total of 177 intestinal content swab samples originating from five wild bird species were investigated for the presence of E. coli and STEC by standard culture methods. Suspect STEC isolates were further characterized by serotyping, random amplified polymorphic DNA polymerase chain reaction (RAPD PCR), antimicrobial resistance pattern and PCR detection of stx1, stx2, and eae genes. Results: A total of 30 suspect STEC isolates from 30 positive birds’ samples were detected and identified on STEC CHROMagar (semi-captive pigeons, 15; house crows, 8; cattle egrets, 3; moorhens, 2; and house teals, 2). 25 isolates were grouped into 13 serogroups (O:20, O:25, O:26, O:27, O:63, O:78, O:111, O:114, O:125, O:128, O:142, O:153, and O:158), while five were rough strains. The distribution of STEC virulence genes among wild birds was as follows: 16 birds carried stx1 gene only (nine pigeons [28.1%], six crows [7.1%], and one cattle egret [5.6%]). Stx1 and stx2 genes together were detected in four birds (one cattle egret [5.6%], two moorhens [6.1%], and one house teal, [10%]). Only one pigeon (3.1%) possessed the three alleles. Disk diffusion test results showed that cefixime was the most effective against STEC serotypes with (93.3%) sensitivity, followed by gentamycin (56.7%), and amoxicillin (50%). On the other hand, all the recovered STEC isolates were resistant to cefotaxime, doxycycline, cephalothin, and sulfisoxazole. RAPD fingerprinting using primers OPA-2 and OPA-9 showed that STEC isolates were heterogeneous; they yielded 30 and 27 different clusters, respectively. Conclusions: Wild birds carry STEC and may add to the contamination of the surrounding environment. PMID:29062203

The role of the dentist in identifying missing and unidentified persons.

PubMed

Riley, Amber D

2015-01-01

The longer a person is missing, the more profound the need for dental records becomes. In 2013, there were >84,000 missing persons and >8,000 unidentified persons registered in the National Crime Information Center (NCIC) database. Tens of thousands of families are left without answers or closure, always maintaining hope that their relative will be located. Law enforcement needs the cooperation of organized dentistry to procure dental records, translate their findings, and upload them into the NCIC database for cross-matching with unidentified person records created by medical examiner and coroner departments across the United States and Canada.

VLA observations of unidentified Leiden-Berkeley Deep-Survey sources - Luminosity and redshift dependence of spectral properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kapahi, V.K.; Kulkarni, V.K.

1990-05-01

VLA observations of a complete subset of the Leiden-Berkeley Deep Survey sources that have S(1.4 GHz) greater than 10 mJy and are not optically identified down to F=22 mag are reported. By comparing the spectral and structural properties of the sources with samples from the literature, an attempt was made to disentangle the luminosity and redshift dependence of the spectral indices of extended emission in radio galaxies and of the incidence of compact steep-spectrum sources. It is found that the fraction of compact sources among those with a steep spectrum is related primarily to redshift, being much larger at highmore » redshifts for sources of similar radio luminosity. Only a weak and marginally significant dependence of spectral indices of the extended sources on luminosity and redshift is found in samples selected at 1.4 and 2.7 GHz. It is pointed out that the much stronger correlation of spectral indices with luminosity may be arising partly from spectral curvature, and partly due to the preferential inclusion of very steep-spectrum sources from high redshift in low-frequency surveys. 54 refs.« less

Mining metadata from unidentified ITS sequences in GenBank: A case study in Inocybe (Basidiomycota)

PubMed Central

2008-01-01

Background The lack of reference sequences from well-identified mycorrhizal fungi often poses a challenge to the inference of taxonomic affiliation of sequences from environmental samples, and many environmental sequences are thus left unidentified. Such unidentified sequences belonging to the widely distributed ectomycorrhizal fungal genus Inocybe (Basidiomycota) were retrieved from GenBank and divided into species that were identified in a phylogenetic context using a reference dataset from an ongoing study of the genus. The sequence metadata of the unidentified Inocybe sequences stored in GenBank, as well as data from the corresponding original papers, were compiled and used to explore the ecology and distribution of the genus. In addition, the relative occurrence of Inocybe was contrasted to that of other mycorrhizal genera. Results Most species of Inocybe were found to have less than 3% intraspecific variability in the ITS2 region of the nuclear ribosomal DNA. This cut-off value was used jointly with phylogenetic analysis to delimit and identify unidentified Inocybe sequences to species level. A total of 177 unidentified Inocybe ITS sequences corresponding to 98 species were recovered, 32% of which were successfully identified to species level in this study. These sequences account for an unexpectedly large proportion of the publicly available unidentified fungal ITS sequences when compared with other mycorrhizal genera. Eight Inocybe species were reported from multiple hosts and some even from hosts forming arbutoid or orchid mycorrhizae. Furthermore, Inocybe sequences have been reported from four continents and in climate zones ranging from cold temperate to equatorial climate. Out of the 19 species found in more than one study, six were found in both Europe and North America and one was found in both Europe and Japan, indicating that at least many north temperate species have a wide distribution. Conclusion Although DNA-based species identification and circumscription are associated with practical and conceptual difficulties, they also offer new possibilities and avenues for research. Metadata assembly holds great potential to synthesize valuable information from community studies for use in a species and taxonomy-oriented framework. PMID:18282272

Stacking Searches for Greater Than 100 MeV Gamma Ray Emission from Radio Galaxies and Seyfert Galaxies

NASA Technical Reports Server (NTRS)

Cillis, A. N.; Hartman, R. C.; Bertsch, D. L.

2003-01-01

The EGRET telescope on CGRO detected more than sixty sources of high-energy gamma radiation associated with active galactic nuclei (AGN). All but one of those belong to the blazar subclass; the only exception is the nearby radio galaxy Centaurus A. Since there is no obvious reason other than proximity to expect Cen A to be the only non-blazar AGN emitting in high-energy gamma rays, we have utilized the "stacking" technique to search for $>100$-MeV emission from two non-blazar AGN subclasses, radio galaxies and Seyfert galaxies. Maps of gamma-ray counts, exposure, and diffuse background have been created, then co-added in varying numbers based on sorts by redshift, 5-GHZ flux density, and optical brightness, and finally tested for gamma-ray emission. No detection significance greater than $2\\sigma$ has been found for any subclass, sorting parameter, or number of objects co-added. Monte Carlo simulations have also been performed, to validate the technique and estimate the significance of the results.

The development of the gamma-ray Cherenkov telescope at the South Pole

NASA Astrophysics Data System (ADS)

Barbagli, G.; Castellini, G.; Landi, G.; Morse, R.; Tasselli, P. L.; Tilav, S.

1993-05-01

An atmospheric Cherenkov telescope (ACT) designated GASP (Gamma Astronomy at the South Pole) has been installed near the SPASE (South Pole Air Shower Experiment) scintillator array at the South Pole Observing Facility. During the austral summer 1992, it was aimed at objects such as PKS 0537-441 and PSR 1706-44, simultaneously with the Egret detector on the Compton Gamma Ray Observatory (CGRO). Recently observed radio silent quasars that emit gamma rays with enormous intensity may account for the origin of cosmic ray flux at energies that exceed 1016 eV. Other galactic sources like Cygnus X-3 are believed to produce the UHE cosmic gamma flux. In addition to SPASE and GASP, a group of particle detectors (AMANDA, ACA, POOL, MICE) are currently being tested. The above instrumentation will constitute the South Pole Observatory Facility. The members of the GASP collaboration are as follows: Firenze: G. Barbagli G. Castellini, G. Landi, P.L. Tasselli; Purdue: J. Gaidos, F. Loeffler, G. Sembroski; C. Wilson; Smithsonian: K. Harris, M.A. Lawrence, T.C. Weekes; Wisconsin K. Engel, F. Halzen R. Morse, P. Surrey, S. Tilav

A predator equalizes rate of capture of a schooling prey in a patchy environment.

PubMed

Vijayan, Sundararaj; Kotler, Burt P; Abramsky, Zvika

2017-05-01

Prey individuals are often distributed heterogeneously in the environment, and their abundances and relative availabilities vary among patches. A foraging predator should maximize energetic gains by selectively choosing patches with higher prey density. However, catching behaviorally responsive and group-forming prey in patchy environments can be a challenge for predators. First, they have to identify the profitable patches, and second, they must manage the prey's sophisticated anti-predator behavior. Thus, the forager and its prey have to continuously adjust their behavior to that of their opponent. Given these conditions, the foraging predator's behavior should be dynamic with time in terms of foraging effort and prey capture rates across different patches. Theoretically, the allocation of its time among patches of behaviorally responsive prey should be such that it equalizes its prey capture rates across patches through time. We tested this prediction in a model system containing a predator (little egret) and group-forming prey (common gold fish) in two sets of experiments in which (1) patches (pools) contained equal numbers of prey, or in which (2) patches contained unequal densities of prey. The egret equalized the prey capture rate through time in both equal and different density experiments. Copyright © 2017 Elsevier B.V. All rights reserved.

EGRET High Energy Capability and Multiwavelength Flare Studies and Solar Flare Proton Spectra

NASA Technical Reports Server (NTRS)

Chupp, Edward L.

1998-01-01

The accomplishments of the participation in the Compton Gamma Ray Observatory Guest investigator program is summarized in this report. The work involved the study of Energetic Gamma Ray Experiment Telescope (EGRET)/Total Absorption Shower Counter(TASC) flare data. The specific accomplishments were the use of the accelerator neutron measurements obtained at the University of New Hampshire to verify the TASC response function and to modify the TASC fitting program to include a high energy neutron contribution, and to determine a high energy neutron contribution to the emissions from the 1991 June 11, solar flare. The next step in the analysis of this event was doing fits to the TASC energy-loss spectra as a function of time. A significant hardening of the solar proton spectrum over time was found for the flare. Further data was obtained from the Yohkoh HXT time histories and images for the 1991 October 27 flare. The results to date demonstrate that the TASC spectral analysis contributes crucial information on the particle spectrum interacting at the Sun. The report includes a paper accepted for publication, a draft of a paper to be delivered at the 26th International Cosmic Ray Conference and an abstract of a paper to be presented at the Meeting of the American Physical Society.

KENNEDY SPACE CENTER, FLA. - A soft-shell turtle with only three legs is seen crossing the tow-way at KSC. The turtle is one of 65 amphibians and reptiles found in the Merritt Island National Wildlife Refuge, which surrounds KSC. The Wildlife Refuge encompasses 92,000 acres that are also a habitat for more than 331 species of birds, 31 mammals and 117 fishes. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, plus a variety of insects.

NASA Image and Video Library

2003-05-29

KENNEDY SPACE CENTER, FLA. - A soft-shell turtle with only three legs is seen crossing the tow-way at KSC. The turtle is one of 65 amphibians and reptiles found in the Merritt Island National Wildlife Refuge, which surrounds KSC. The Wildlife Refuge encompasses 92,000 acres that are also a habitat for more than 331 species of birds, 31 mammals and 117 fishes. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, plus a variety of insects.

KENNEDY SPACE CENTER, FLA. - A closeup of a soft-shell turtle seen crossing the tow-way at KSC. The turtle is one of 65 amphibians and reptiles found in the Merritt Island National Wildlife Refuge, which surrounds KSC. The Wildlife Refuge encompasses 92,000 acres that are also a habitat for more than 331 species of birds, 31 mammals and 117 fishes. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, plus a variety of insects.

NASA Image and Video Library

2003-05-29

KENNEDY SPACE CENTER, FLA. - A closeup of a soft-shell turtle seen crossing the tow-way at KSC. The turtle is one of 65 amphibians and reptiles found in the Merritt Island National Wildlife Refuge, which surrounds KSC. The Wildlife Refuge encompasses 92,000 acres that are also a habitat for more than 331 species of birds, 31 mammals and 117 fishes. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, plus a variety of insects.

Predator removal enhances waterbird restoration in Chesapeake Bay (Maryland)

USGS Publications Warehouse

Erwin, R. Michael; McGowan, Peter C.; Reese, Jan

2011-01-01

This report represents an update to an earlier report(Erwin et al. 2007a) on wildlife restoration on the largest dredge material island project in the United States underway in Talbot County, Maryland (Figure 1) in the mid–Chesapeake Bay region, referred to as the Paul Sarbanes Ecosystem Restoration Project at Poplar Island (www.nab.usace.army.mil/projects/Maryland/PoplarIsland/documents.html). An important component of this largescale restoration effort focused on water birds, as many of these species have undergone significant declines in the Chesapeake region over the past 30 years (Erwin et al. 2007b). The priority waterbird species include common terns (Sterna hirundo), least terns (S. antillarum), snowy egrets (Egretta thula), and ospreys (Pandion haliaetus). Although significant numbers of common terns (more than 800 pairs in 2003), least terns (62 pairs in 2003), snowy egrets (50 or more pairs by 2005), and ospreys (7 to 10 pairs) have nested on Poplar Island since early 2000, tern productivity especially had been strongly limited by a combination of red fox (Vulpes vulpes) and great horned owl (Bubo virginianus) predation. Fox trapping began in 2004, and four were removed that year; no more evidence of fox presence was found in 2005 or subsequently. The owls proved to be more problematic.

Blazar Astronomy above 50 GeV

NASA Astrophysics Data System (ADS)

Smith, D. A.

This contribution is dedicated to the memory of Chaman L. Bhat, an atmospheric Cherenkov pioneer and a leader of the Indian gamma-ray community, who died in a road accident on Mt. Abu on December 17, just after the workshop. While few blazars have been detected beyond EGRET energies, these extreme cases may be the ones that 'make or break' some models describing blazars in particular, and therefore AGNs in general. This paper first reviews the status of the various atmospheric Cherenkov gamma-ray telescopes. We then describe the most recent results from these instruments, paying particular attention to the recent detection of 1ES 1426+428 by the Whipple, CAT, and HEGRA imagers. We illustrate the dilemma of target selection using the example of W Com. We then discuss the consequences of the first measurements of Mrk 421 below 100 GeV by the solar heliostat arrays CELESTE and STACEE. This first foray into the energy range linking EGRET with the current imagers requires us to start using functional forms for the spectral energy distributions that are more physical than the simple power laws (or parabolas) used up to now to describe the imager or satellite results. We can hope that HESS, followed by MAGIC and VERITAS, as well as CELESTE and STACEE, will make this a recurring problem in 2002 and 2003.

KENNEDY SPACE CENTER, FLA. -- A roseate spoonbill contemplates its reflection in the water near KSC. Spoonbills prefer to inhabit mangroves, ranging from the coasts of southern Florida, Louisiana and Texas, to the West Indies, Mexico, Central and South America. They feed on shrimps and fish in shallow waters. Spoonbills are one of 310 species of birds that inhabit the Merritt Island National Wildlife Refuge, which shares a boundary with KSC. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

NASA Image and Video Library

2004-01-08

KENNEDY SPACE CENTER, FLA. -- A roseate spoonbill contemplates its reflection in the water near KSC. Spoonbills prefer to inhabit mangroves, ranging from the coasts of southern Florida, Louisiana and Texas, to the West Indies, Mexico, Central and South America. They feed on shrimps and fish in shallow waters. Spoonbills are one of 310 species of birds that inhabit the Merritt Island National Wildlife Refuge, which shares a boundary with KSC. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

KENNEDY SPACE CENTER, FLA. -- Two roseate spoonbills hunt for their supper in the water near KSC. Spoonbills prefer to inhabit mangroves, ranging from the coasts of southern Florida, Louisiana and Texas, to the West Indies, Mexico, Central and South America. They feed on shrimps and fish in shallow waters. Spoonbills are one of 310 species of birds that inhabit the National Merritt Island Wildlife Refuge, which shares a boundary with KSC. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

NASA Image and Video Library

2004-01-08

KENNEDY SPACE CENTER, FLA. -- Two roseate spoonbills hunt for their supper in the water near KSC. Spoonbills prefer to inhabit mangroves, ranging from the coasts of southern Florida, Louisiana and Texas, to the West Indies, Mexico, Central and South America. They feed on shrimps and fish in shallow waters. Spoonbills are one of 310 species of birds that inhabit the National Merritt Island Wildlife Refuge, which shares a boundary with KSC. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

Congener-specific polychlorinated biphenyl patterns in eggs of aquatic birds from the lower Laguna Madre, Texas

USGS Publications Warehouse

Mora, Miguel A.

1996-01-01

Eggs from four aquatic bird species nesting in the Lower Laguna Madre, Texas, were collected to determine differences and similarities in the accumulation of congener-specific polychlorinated biphenyls (PCBs) and to evaluate PCB impacts on reproduction. Because of the different toxicities of PCB congeners, it is important to know which congeners contribute most to total PCBs. The predominant PCB congeners were 153, 138, 180, 110, 118, 187, and 92. Collectively, congeners 153, 138, and 180 accounted for 26 to 42% of total PCBs. Congener 153 was the most abundant in Caspian terns (Sterna caspia) and great blue herons (Ardea herodias) and congener 138 was the most abundant in snowy egrets (Egretta thula) and tricolored herons (Egretta tricolor). Principal component analysis indicated a predominance of higher chlorinated biphenyls in Caspian terns and great blue herons and lower chlorinated biphenyls in tricolored herons. Snowy egrets had a predominance of pentachlorobiphenyls. These results suggest that there are differences in PCB congener patterns in closely related species and that these differences are more likely associated with the species' diet rather than metabolism. Total PCBs were significantly greater (p < 0.05) in Caspian terns than in the other species. Overall, PCBs in eggs of birds from the Lower Laguna Madre were below concentrations known to affect bird reproduction.

Unidentified Flying Objects, A Selected Bibliography.

ERIC Educational Resources Information Center

Rodgers, Kay, Comp.

This bibliography, intended for the general reader, provides selective coverage of the unidentified flying object (UFO) literature that has appeared since 1969. The coverage is limited to English language works, but does include translations and materials published abroad. Other bibliographies are listed, as are books, congressional and other…

UNIDENTIFIED CATENARY SUSPENSION BRIDGE, SHOWING RIVETED METAL PIERS UNDER CONSTRUCTION. ...

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

UNIDENTIFIED CATENARY SUSPENSION BRIDGE, SHOWING RIVETED METAL PIERS UNDER CONSTRUCTION. NOTE APPROACH SPANS OF PIPE CONSTRUCTION IN RIGHT BACKGROUND. 3/4 VIEW FROM BELOW. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

METHODS AND TECHNIQUES FOR DEALING WITH THE UNIDENTIFIED FRACTION OF COMPLEX MIXTURES

EPA Science Inventory

For the vast majority of highly complex environmental mixtures to which humans are exposed, significant portions of the mixture are unidentified. Although toxicological data on the mixture itself are desired for risk assessment, such data, even on a similar mixture, are rarely a...

Alternative Fuels Data Center: Maps and Data

Science.gov Websites

vehicles with unidentified fuel types. Data consists of registered vehicles in operation in the United fuel types with small populations, such as methanol and hydrogen vehicles. See relative vehicle completed a conversion. "undefined" values are vehicles with unidentified fuel types. Data

Augmentation of French grunt diet description using combined visual and DNA-based analyses

USGS Publications Warehouse

Hargrove, John S.; Parkyn, Daryl C.; Murie, Debra J.; Demopoulos, Amanda W.J.; Austin, James D.

2012-01-01

Trophic linkages within a coral-reef ecosystem may be difficult to discern in fish species that reside on, but do not forage on, coral reefs. Furthermore, dietary analysis of fish can be difficult in situations where prey is thoroughly macerated, resulting in many visually unrecognisable food items. The present study examined whether the inclusion of a DNA-based method could improve the identification of prey consumed by French grunt, Haemulon flavolineatum, a reef fish that possesses pharyngeal teeth and forages on soft-bodied prey items. Visual analysis indicated that crustaceans were most abundant numerically (38.9%), followed by sipunculans (31.0%) and polychaete worms (5.2%), with a substantial number of unidentified prey (12.7%). For the subset of prey with both visual and molecular data, there was a marked reduction in the number of unidentified sipunculans (visual – 31.1%, combined &ndash 4.4%), unidentified crustaceans (visual &ndash 15.6%, combined &ndash 6.7%), and unidentified taxa (visual &ndash 11.1%, combined &ndash 0.0%). Utilising results from both methodologies resulted in an increased number of prey placed at the family level (visual &ndash 6, combined &ndash 33) and species level (visual &ndash 0, combined &ndash 4). Although more costly than visual analysis alone, our study demonstrated the feasibility of DNA-based identification of visually unidentifiable prey in the stomach contents of fish.

1. Photocopy of photograph showing unidentified launch area with personnel ...

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

1. Photocopy of photograph showing unidentified launch area with personnel door, decontamination shower and Ajax missiles from photo archives at U. S. Institute for Military History, Carlisle Barracks, Carlisle, PA, no date - NIKE Missile Battery PR-79, East Windsor Road south of State Route 101, Foster, Providence County, RI

43 CFR 10.11 - Disposition of culturally unidentifiable human remains.

Code of Federal Regulations, 2013 CFR

2013-10-01

... human remains. 10.11 Section 10.11 Public Lands: Interior Office of the Secretary of the Interior NATIVE AMERICAN GRAVES PROTECTION AND REPATRIATION REGULATIONS Human Remains, Funerary Objects, Sacred Objects, or... unidentifiable human remains. (a) General. This section implements section 8(c)(5) of the Act and applies to...

43 CFR 10.11 - Disposition of culturally unidentifiable human remains.

Code of Federal Regulations, 2014 CFR

2014-10-01

... human remains. 10.11 Section 10.11 Public Lands: Interior Office of the Secretary of the Interior NATIVE AMERICAN GRAVES PROTECTION AND REPATRIATION REGULATIONS Human Remains, Funerary Objects, Sacred Objects, or... unidentifiable human remains. (a) General. This section implements section 8(c)(5) of the Act and applies to...

43 CFR 10.11 - Disposition of culturally unidentifiable human remains.

Code of Federal Regulations, 2012 CFR

2012-10-01

... human remains. 10.11 Section 10.11 Public Lands: Interior Office of the Secretary of the Interior NATIVE AMERICAN GRAVES PROTECTION AND REPATRIATION REGULATIONS Human Remains, Funerary Objects, Sacred Objects, or... unidentifiable human remains. (a) General. This section implements section 8(c)(5) of the Act and applies to...

The Utilization of Classifications in High-Energy Astrophysics Experiments

NASA Astrophysics Data System (ADS)

Atwood, Bill

2012-03-01

The history of high-energy gamma observations stretches back several decades. But it was with the launch of the Energetic Gamma Ray Experiment Telescope (EGRET) in 1991 onboard the Compton Gamma Ray Observatory (CGRO) [1], that the field entered a new era of discovery. At the high-energy end of the electromagnetic spectrum, incoming particles of light, photons, interact with matter mainly by producing electron-positron pairs and this process dominates above an energy of 10-30MeV depending on the material. To a high degree the directionality of the incoming gamma ray is reflected in the e+ and e-, and hence the detection of the trajectories of the e+e- pair can be used to infer the direction of the originating photon. Measuring these high-energy charged particles is the domain of high-energy particle physics and so it should be of little surprise that particle physicists played a significant role in the design and construction of EGRET, as well as the design and implementation of analysis methods for the resulting data. Prior to EGRET, only a handful of sources in the sky were known as high-energy gamma-ray emitters. During EGRET's 9-years mission the final catalog included over 270 sources including new types such as Gamma Ray Bursts (GRBs). This set the stage for the next-generation mission, the Gamma ray Large Area Space Telescope (GLAST) [2]. Very early in the EGRET mission, the realization that the high-energy gamma-ray sky was extremely interesting led to a competition to develop the next-generation instruments. The technology used in EGRET was frozen in the late 1970s and by 1992, enormous advances had been made in experimental particle physics. In particular the effort to develop solid state detectors, targeted for use at the Super Conducting Super Collider (SSC), had made the technology of silicon strip detectors (SSDs) commercially viable for use in large area arrays. Given the limitations imposed by the space environment (e.g., operate in a vacuum, scarce availability of electric power, etc.), this was the ideal technology for the next gamma-ray mission. Consistent with contemporary practice in particle physics, a nearly complete and detailed computer model of GLAST was made to study performance and optimize the design. The jargon in the field refers to such models generically as "the Monte Carlo" (MC) and it included a complete suite of radiation transport codes modeling most of the known interactions that particles undergo upon passage through matter. The MC is also used to provide a randomized source of incoming particles which can be made to mimic celestial sources of gamma rays as well as background cosmic rays. The cosmic rays referred to here are comprised of two main components: trapped radiation in the earth's magnetosphere and a flux of primary charged particles originating from outside. Both fluxes contain a variety of particle types including protons, heavier nuclei, electrons, and positrons. It cannot be emphasized too strongly the value that such a tool brings. Having the "Monte Carlo Truth" for each simulated event allows for the evaluation of what went right and what went wrong both at the detector level as well as at the data analysis level. The Monte Carlo simulations of GLAST are at the heart of its success today. The simulations allowed for the development of the reconstruction analysis (RA) of the flight data prior to the existence of the instrument. The RA transforms the collections of sensor readouts in an event into tracks, energies, and other higher analysis entities. In the case of GLAST, there were many iterations of the RA, first to prove the merits of the design and then, post awarding of the flight instrument contract, the creation of the code to be used in the initial phases of the mission. Since then, the now renamed Fermi-LAT mission is engaged in the 8th such iteration. Critical to the success of any experiment are the identification and quantification of the "signal." Mostly all experiments have backgrounds or artifacts which obscure a clear signal and in the area of high-energy gamma-ray astronomy the situation is extreme. By the very nature of the detection method for gamma rays, it leaves the apparatus vulnerable to interpret cosmic rays as "signal." In low earth orbit the incoming rate of cosmic rays can exceed the gamma-ray rate by over 10,000. To achieve residual background levels in the percent range requires an aggregate separation power of upwards to a million-to-one while at the same time preserving a high efficiency for capturing the signal. From the triggering, to onboard filtering and ultimately the analysis on the ground, the goal is the same: kill background - keep gamma rays. The LAT, the hardware trigger, is a combination of sensor responses coincident at the microsecond timescale, causing all the sensors to be readout forming an "event." The LAT trigger was constructed to be highly efficient for gamma rays and as inefficient as possible for cosmic rays. The rejection power achieved by the trigger is about 5:1 while retaining over 98% efficiency for gamma rays. This still leaves a data event stream hopelessly large to downlink to the ground. A bank of onboard computers does a preliminary event reconstruction to increase the rejection power. For the LAT, this resulted in another factor of ∼5 while maintaining a gamma-ray efficiency of over 96%. Hence, what is downlinked to ground is an orbit averaged rate of about 400 cps of which only a few cps are gamma rays. All this complexity as to actual event composition (e.g., which cosmic ray events make it to the ground), is modeled in the simulations and provides a realistic facsimile to real data and this serves as the input to the ground analysis. Part of the requirements for the mission was to demonstrate prior to launch that the science goals were achievable and this included background rejection at a specified level. During the several years of development working toward this goal it was realized that the science requirements as written were not achievable mainly due to a background which we termed as "irreducible." Positrons hitting the outer protective layers of the LAT (the thermal blanket and micrometeor shield) can annihilate with the atomic electrons producing gammas and cosmic ray protons interacting with the same material produce neutral pions which then promptly decay into two gamma rays. In some cases, the only particles entering the fiducial volume of the detector are gamma rays from these processes and they are indistinguishable from celestial gamma rays. The rejection was increased until the majority of the remainder was "irreducible" in origin along with a demonstration that this residual could be subtracted with appropriately small systematic errors. The LAT instrument and reconstruction of the gamma-ray data from it fall into the realm of particle physics. Our first attempts at background rejection followed standard practice in particle physics: identify good discrimination variables and make cuts. What is meant by "cuts" is to accept (or reject) events for which a given variable (or variables) falls within (or outside) a certain range of values. This method, however, soon revealed itself to be inadequate especially when considering the resulting efficiency for retaining gamma rays. We then turned to data mining techniques which had seen considerable success in the life sciences and financial industries. In the end the classification tree technology was found to be inadequate by itself. A hybrid approach was developed in which first cuts are made using some of the discrimination variables to whittle down the problem and then the simplified problem is solved using a classification tree. In the next section we will see why classification trees offer a substantial increase in efficiency over the "cut and keep" paradigm. Other machine learning methods were tried, such as neural nets, but they were found to be inferior for this problem. It should come as little surprise to find that other gamma-ray experiments also found the classification tree technology advantageous for similar reasons. In particular the ground based Imaging Air Cherenkov Telescope (IACT), MAGIC [3], successfully developed a background rejection for its data based on classification trees. There are several packages which provide classification tree (CT)-based technology [4]. Some of these are commercial while others are free. Please see the references for specifics. In the discussion which follows, the commercial product by TIBCO (SpotfireMiner) is used [5].

The faint X-ray sources in and out of omega Centauri: X-ray observations and optical identifications

NASA Technical Reports Server (NTRS)

Cool, Adrienne M.; Grindlay, Jonathan E.; Bailyn, Charles D.; Callanan, Paul J.; Hertz, Paul

1995-01-01

We present the results of an observation of the globular cluster omega Cen (NGC 5139) with the Einstein high-resolution imager (HRI). Of the five low-luminosity X-ray sources toward omega Cen which were first identified with the Einstein imaging proportional counter (IPC) (Hertz and Grindlay 1983a, b), two are detected in the Einstein HRI observation: IPC sources A and D. These detections provide source positions accurate to 3 sec-4 sec; the positions are confirmed in a ROSAT HRI observation reported here. Using CCD photometry and spectroscopy, we have identified both sources as foreground dwarf M stars with emission lines (dMe). The chance projection of two Mde stars within approximately 13 min of the center of omega Cen is not extraordinary, given the space density of these stellar coronal X-ray sources. We discuss the possible nature of the three as yet unidentified IPC sources toward omega Cen, and consider the constraints that the Einstein observations place on the total population of X-ray sources in this cluster. The integrated luminosity from faint X-ray sources in omega Cen appears to be low relative to both the old open cluster M67 and the post-core-collapse globular, NGC 6397.

Nonthermal processes around collapsed objects: High energy gamma ray sources in the radio sky

NASA Technical Reports Server (NTRS)

Helfand, David J.; Ruderman, Malvin; Applegate, James H.; Becker, Robert H.

1993-01-01

In our proposal responding to the initial Guest Observer NRA for the Compton Gamma Ray Observatory, 'Nonthermal Processes Around Collapsed Objects: High Energy Gamma Ray Sources in the Radio Sky', we stated that 'At high energies - the identity of the principal Galactic source population remains unknown' although the 'one certain source of high energy emission is young radio pulsars'. These two statements remain true, although at this writing, eighteen months after the beginning of the Compton allsky survey, much of the gamma-ray data required to greatly extend our knowledge of the Galaxy's high energy emission has been collected. The thrust of the program supported by our grant was to collect and analyze a complementary set of data on the Milky Way at radio wavelengths in order to help identify the dominant Pop 1 component of the Galaxy's gamma ray sources, and to pursue theoretical investigations on the origins and emission mechanisms of young pulsars, the one component of this population identified to date. We summarize here our accomplishments under the grant. In Section 2, we describe our VLA surveys of the Galactic Plane along with the current status of the radio source catalogs derived therefrom; unfortunately, owing to the TDRSS antenna problem and subsequent extension of the Sky Survey, we were not able to carry out a comparison with the EGRET data directly, although everything is now in place to do so as soon as it becomes available. In Section 2, we summarize our progress on the theoretical side, including the substantial completion of a dissertation on pulsar origins and work on the high energy emission mechanisms of isolated pulsars. We list the personnel supported by the grant in section 4 and provide a complete bibliography of publications supported in whole or in part by the grant in the final section.

KSC-2014-2922

NASA Image and Video Library

2014-06-13

CAPE CANAVERAL, Fla. -- A white egret is reflected in the water as it fishes on NASA's Kennedy Space Center in Florida. The undeveloped property on Kennedy Space Center is managed by the U.S. Fish and Wildlife Service through the Merritt Island National Wildlife Refuge. The refuge provides a habitat for a plethora of wildlife, including 330 species of birds. For information on the refuge, visit http://www.fws.gov/merrittisland/Index.html. Photo credit: NASA/Daniel Casper

KSC-2014-2930

NASA Image and Video Library

2014-06-13

CAPE CANAVERAL, Fla. -- This great egret strikes a classic pose amid the brush on NASA's Kennedy Space Center in Florida. The undeveloped property on Kennedy Space Center is managed by the U.S. Fish and Wildlife Service through the Merritt Island National Wildlife Refuge. The refuge provides a habitat for a plethora of wildlife, including 330 species of birds. For information on the refuge, visit http://www.fws.gov/merrittisland/Index.html. Photo credit: NASA/Daniel Casper

KSC-2014-2928

NASA Image and Video Library

2014-06-13

CAPE CANAVERAL, Fla. -- This molting great egret is in its natural habitat in the tall grass on NASA's Kennedy Space Center in Florida. The undeveloped property on Kennedy Space Center is managed by the U.S. Fish and Wildlife Service through the Merritt Island National Wildlife Refuge. The refuge provides a habitat for a plethora of wildlife, including 330 species of birds. For information on the refuge, visit http://www.fws.gov/merrittisland/Index.html. Photo credit: NASA/Daniel Casper

VIEW OF PARTIALLY EXCAVATED MILL RUINS LOOKING NORTHWEST SHOWING UNIDENTIFIED ...

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

VIEW OF PARTIALLY EXCAVATED MILL RUINS LOOKING NORTHWEST SHOWING UNIDENTIFIED PIT IN RIGHT FOREGROUND, MASONRY BASE FOR STEAM ENGINE AND CANE MILL IN LEFT CENTER, PURGING HOUSE AND CHIMNEY IN BACKGROUND - Hacienda Azucarera La Esperanza, Mill (Ruins), 2.65 miles North of PR Route 2 Bridge Over Manati River, Manati, Manati Municipio, PR

14. UNIDENTIFIED CABLESTAYED SUSPENSION BRIDGE WITH TIMBER RAILING OF TEN ...

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

14. UNIDENTIFIED CABLE-STAYED SUSPENSION BRIDGE WITH TIMBER RAILING OF TEN PANELS AND STONE PIER, SHOWING ELEMENTS SIMILAR TO E.E. RUNYON'S SUSPENSION BRIDGE PATENTS, BUT ALTERNATE CABLE PATTERN. 3/4 VIEW FROM BELOW. - Bluff Dale Suspension Bridge, Spanning Paluxy River at County Route 149, Bluff Dale, Erath County, TX

13. UNIDENTIFIED CABLESTAYED SUSPENSION BRIDGE WITH TIMBER RAILING OF TWELVE ...

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

13. UNIDENTIFIED CABLE-STAYED SUSPENSION BRIDGE WITH TIMBER RAILING OF TWELVE PANELS, SHOWING CABLE PATTERN SIMILAR TO E.E. RUNYON'S SUSPENSION BRIDGE PATENTS. THE BLUFF DALE SUSPENSION BRIDGE'S CABLES MAY HAVE ORIGINALLY FOLLOWED THIS PATTERN. ELEVATION VIEW. - Bluff Dale Suspension Bridge, Spanning Paluxy River at County Route 149, Bluff Dale, Erath County, TX

Comparison of L-serine uptake by human placental microvillous membrane vesicles and placental villous fragments.

PubMed

Brand, A P; Greenwood, S L; Glazier, J D; Bennett, E J; Godfrey, K M; Sibley, C P; Hanson, M A; Lewis, R M

2010-05-01

Both syncytiotrophoblast microvillous plasma membrane vesicles (MVM) and placental villous fragments are used to characterize the placental uptake of maternal substrate and to investigate changes in uptake associated with pathological conditions. However, the two techniques have not been directly compared. In this study uptake of (14)C-L-serine was compared in placental villous fragments and in MVM prepared from the same placentas. (14)C-L-serine uptake into MVM vesicles was mediated by System L and System A and smaller unidentified Na(+)-dependent and Na(+)-independent components. In villous fragments an unidentified Na(+)-dependent component mediated the majority of (14)C-L-serine uptake followed by System A and System L. The unidentified Na(+)-independent component of L-serine uptake was not detected in villous fragments. The ratio of System A activity to System L activity was similar in villous fragments and MVM vesicles. However, the unidentified Na(+)-dependent component in villous fragments was significantly higher than that in MVM vesicles. This indicates that the main differences in serine uptake mechanisms identified using the two techniques were not due to differences in System A and System L activity but to differences in the unidentified Na(+)-dependent component. This study suggests that uptake of L-serine into MVM vesicles and villous fragments via Systems A and L is comparable, but that this is not true for all components of L-serine uptake. (c) 2010 Elsevier Ltd. All rights reserved.

Mucilaginibacter pedocola sp. nov., isolated from a heavy-metal-contaminated paddy field.

PubMed

Tang, Jingwei; Huang, Jing; Qiao, Zixu; Wang, Rui; Wang, Gejiao

2016-10-01

Strain TBZ30T was isolated from soil of a heavy-metal-contaminated paddy field. Cells of strain TBZ30T were Gram-staining-negative, rod-shaped, non-motile and non-spore-forming. The isolate was strictly aerobic, pink-pigmented, catalase- and oxidase-positive and produced exopolysaccharides. On the basis of 16S rRNA gene phylogeny, strain TBZ30T belonged to the genus Mucilaginibacter and appeared most closely related to Mucilaginibacter gynuensis YC7003T (95.8 %), Mucilaginibacter litoreus BR-18T (95.4 %) and Mucilaginibacter mallensis MP1X4T (95.4 %). Strain TBZ30T contained menaquinone-7 as the only ubiquinone. The main cellular fatty acids included summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH), iso-C15 : 0, C16 : 0, iso-C17 : 0 3-OH and C16 : 1ω5c. The polar lipids were phosphatidylethanolamine, an unidentified phospholipid, two unidentified aminophospholipids, four unidentified aminolipids, three unidentified lipids and two unidentified glycolipids. The genomic DNA G+C content was 49.0 mol%. On the basis of polyphasic taxonomy analyses, strain TBZ30T represents a novel species of the genus Mucilaginibacter, for which the name Mucilaginibacter pedocola sp. nov. is proposed. The type strain is TBZ30T (=KCTC 42833T=CCTCC AB 2015301T).

Dutch population specific sex estimation formulae using the proximal femur.

PubMed

Colman, K L; Janssen, M C L; Stull, K E; van Rijn, R R; Oostra, R J; de Boer, H H; van der Merwe, A E

2018-05-01

Sex estimation techniques are frequently applied in forensic anthropological analyses of unidentified human skeletal remains. While morphological sex estimation methods are able to endure population differences, the classification accuracy of metric sex estimation methods are population-specific. No metric sex estimation method currently exists for the Dutch population. The purpose of this study is to create Dutch population specific sex estimation formulae by means of osteometric analyses of the proximal femur. Since the Netherlands lacks a representative contemporary skeletal reference population, 2D plane reconstructions, derived from clinical computed tomography (CT) data, were used as an alternative source for a representative reference sample. The first part of this study assesses the intra- and inter-observer error, or reliability, of twelve measurements of the proximal femur. The technical error of measurement (TEM) and relative TEM (%TEM) were calculated using 26 dry adult femora. In addition, the agreement, or accuracy, between the dry bone and CT-based measurements was determined by percent agreement. Only reliable and accurate measurements were retained for the logistic regression sex estimation formulae; a training set (n=86) was used to create the models while an independent testing set (n=28) was used to validate the models. Due to high levels of multicollinearity, only single variable models were created. Cross-validated classification accuracies ranged from 86% to 92%. The high cross-validated classification accuracies indicate that the developed formulae can contribute to the biological profile and specifically in sex estimation of unidentified human skeletal remains in the Netherlands. Furthermore, the results indicate that clinical CT data can be a valuable alternative source of data when representative skeletal collections are unavailable. Copyright © 2017 Elsevier B.V. All rights reserved.

A search for pre-main-sequence stars in high-latitude molecular clouds. 3: A survey of the Einstein database

NASA Technical Reports Server (NTRS)

Caillault, Jean-Pierre; Magnani, Loris; Fryer, Chris

1995-01-01

In order to discern whether the high-latitude molecular clouds are regions of ongoing star formation, we have used X-ray emission as a tracer of youthful stars. The entire Einstein database yields 18 images which overlap 10 of the clouds mapped partially or completely in the CO (1-0) transition, providing a total of approximately 6 deg squared of overlap. Five previously unidentified X-ray sources were detected: one has an optical counterpart which is a pre-main-sequence (PMS) star, and two have normal main-sequence stellar counterparts, while the other two are probably extragalactic sources. The PMS star is located in a high Galactic latitude Lynds dark cloud, so this result is not too suprising. The translucent clouds, though, have yet to reveal any evidence of star formation.

Identifying sources of tick blood meals using unidentified tandem mass spectral libraries.

PubMed

Önder, Özlem; Shao, Wenguang; Kemps, Brian D; Lam, Henry; Brisson, Dustin

2013-01-01

Rapid and reliable identification of the vertebrate species on which a disease vector previously parasitized is imperative to study ecological factors that affect pathogen distribution and can aid the development of public health programs. Here we describe a proteome profiling technique designed to identify the source of blood meals of haematophagous arthropods. This method employs direct spectral matching and thus does not require a priori knowledge of any genetic or protein sequence information. Using this technology, we detect remnants of blood in blacklegged ticks (Ixodes scapularis) and correctly determine the vertebrate species from which the blood was derived, even 6 months after the tick had fed. This biological fingerprinting methodology is sensitive, fast, cost-effective and can potentially be adapted for other biological and medical applications when existing genome-based methods are impractical or ineffective.

VizieR Online Data Catalog: VLT/SINFONI observations of MIPSGAL "bubbles" (Silva+, 2017)

NASA Astrophysics Data System (ADS)

Silva, K. M.; Flagey, N.; Noriega-Crespo, A.; Carey, S.; Ingallinera, A.

2018-04-01

Data were acquired in service mode during UT 2014 May 23-June 7 using VLT/SINFONI observations. We used two of SINFONI's four gratings providing spectral resolutions R=3000 and 4000 in the H and K bands, respectively, with the field of view of 8" by 8" (without adaptive optics). The targets are 55 MIPSGAL "bubbles" (MBs) that have not been previously classified as PNe, whose central sources were unidentified at the time of the Period 93 Call for Proposals (UT 2013 October 01), and appeared to contain at least one potential central source detected in the near-IR images of the Two Micron All-Sky Survey (2MASS, Skrutskie et al. 2006, Cat. VII/233) or the UKIRT Infrared Deep Sky Survey (UKIDSS, Warren et al. 2007MNRAS.381.1400W). (5 data files).

Optical spectroscopic followup of XMMSL1 J164303.7+653253 in the error box of IGR J16426+6536

NASA Astrophysics Data System (ADS)

Parisi, P.; Masetti, N.; Malizia, A.; Morelli, L.; Mason, E.; Dean, A. J.; Ubertini, P.

2008-10-01

We report on a spectroscopic observation of the optical object USNO-A2.0 1500-06133361 (with J2000 coordinates RA = 16 43 04.07, Dec = +65 32 50.9 and magnitude R ~ 18.9) inside the error circle of the XMM-Newton slew source XMMLS1 J164303.7+653253 (see Ibarra et al., ATel #1397), possibly associated with the unidentified INTEGRAL source IGR J16426+6536 (Bird et al. 2007, ApJS, 170, 175). The observations were performed on 2008 February 04, starting at 06:10 UT, with DOLORES, a focal reducer instrument installed on the 3.58m Telescopio Nazionale Galileo (TNG) in the Astronomical Observatory of Roque de Los Muchachos (Santa Cruz de La Palma, Spain), for a total exposure time of 1800 s.

The Fulton County Medical Examiner's experience with the Federal Bureau of Investigation National Missing Person DNA Database Program, 2004-2007.

PubMed

Heninger, Michael; Hanzlick, Randy

2011-03-01

Medical examiners and coroners occasionally encounter unidentified human bodies, which remain unidentified for extended periods. In such cases, when traditional methods of identification have failed or cannot be used, DNA profiling may be used. The Federal Bureau of Investigation has a National Missing Person DNA database (NMPDD) laboratory to which samples may be submitted on such cases and from possible relatives or environments of unidentified decedents. This article describes the experience of the Fulton County Medical Examiner (FCME) in submitting samples to the NMPDD laboratory. A database was established at the FCME to track the submission of samples from unidentified decedents to the NMPDD laboratory for DNA testing along with the results and turnaround times. In December 2004, the FCME inventoried all cases for which samples were available and began to submit them to the NMPDD laboratory for testing. DNA testing and isolation rates, sample type, and turnaround times were tabulated in October 2006 for samples submitted between December 16, 2004 and December 16, 2005. An overall summary of data was also prepared concerning the status of all samples submitted as of April 17, 2007. During the 1-year study period, samples from 77 unidentified decedents were submitted to the laboratory. As of October 2006 (22 months after submission of the first samples and 10 months after submission of the last samples), testing had been completed on 53% of the samples submitted, and 68% of those tested resulted in a mitochondrial DNA profile. Turnaround times ranged from 66 to 557 days, improved with time, and had a mean of 107 days for specimens submitted during the latter part of the study period. As of April 17, 2007, we had submitted samples involving 84 unidentified decedents. Seventy-five percent of the samples have now been tested. Data from the NMPDD laboratory have resulted in 4 identifications by comparison with putative relatives, 4 exclusions, and no cold hits through comparison NMPDD DNA profiles from missing persons. More extensive data are presented in the body of this article. The NMPDD laboratory provides useful and free services to medical examiners, coroners, and law enforcement agencies that require DNA services regarding missing and unidentified persons. Turnaround times have improved. The success of the system in getting cold hits will be heavily dependent on law enforcement filing missing persons reports and submission of reference samples from putative relatives of the decedent. We recommend collecting specimens for DNA analysis early on in the postmortem investigation, submitting samples to the NMPDD laboratory or one of its participating laboratories when traditional methods for identification cannot be used or have failed, not burying bodies until a DNA profile has been obtained, and not cremating unidentified remains.

SENSITIVITY OF BLIND PULSAR SEARCHES WITH THE FERMI LARGE AREA TELESCOPE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dormody, M.; Johnson, R. P.; Atwood, W. B.

2011-12-01

We quantitatively establish the sensitivity to the detection of young to middle-aged, isolated, gamma-ray pulsars through blind searches of Fermi Large Area Telescope (LAT) data using a Monte Carlo simulation. We detail a sensitivity study of the time-differencing blind search code used to discover gamma-ray pulsars in the first year of observations. We simulate 10,000 pulsars across a broad parameter space and distribute them across the sky. We replicate the analysis in the Fermi LAT First Source Catalog to localize the sources, and the blind search analysis to find the pulsars. We analyze the results and discuss the effect ofmore » positional error and spin frequency on gamma-ray pulsar detections. Finally, we construct a formula to determine the sensitivity of the blind search and present a sensitivity map assuming a standard set of pulsar parameters. The results of this study can be applied to population studies and are useful in characterizing unidentified LAT sources.« less

GMRT discovery of PSR J1544+4937: An eclipsing black-widow pulsar identified with a Fermi-LAT source

DOE PAGES

Bhattacharyya, B.; Roy, J.; Ray, P. S.; ...

2013-07-29

Using the Giant Metrewave Radio Telescope, we performed deep observations to search for radio pulsations in the directions of unidentified Fermi-Large Area Telescope γ-ray sources. We report the discovery of an eclipsing black-widow millisecond pulsar, PSR J1544+4937, identified with the uncataloged γ-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 (Mc > 0.017M ⊙). 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 ingressmore » phase are observed, indicating a clumpy and variable eclipsing medium. Moreover, additional short-duration absorption events are observed around the eclipse boundaries. Finally, using the radio timing ephemeris we were able to detect γ-ray pulsations from this pulsar, confirming it as the source powering the γ-ray emission.« less

The first γ-ray detection of the narrow-line Seyfert 1 FBQS J1644+2619

DOE PAGES

D'Ammando, F.; Orienti, M.; Larsson, J.; ...

2015-07-06

Here, we report the discovery of γ-ray emission from the narrow-line Seyfert 1 (NLSy1) galaxy FBQS J1644+2619 by the Large Area Telescope on board the Fermi satellite. The Third Fermi LAT Source catalogue reports an unidentified γ-ray source, detected over the first four years of Fermi operation, 0.°23 from the radio position of the NLSy1. Analysing 76 months of γ-ray data (2008 August 4–2014 December 31) we are able to better constrain the localization of the γ-ray source. The new position of the γ- ray source is 0.°05 from FBQS J1644+2619, suggesting a spatial association with the NLSy1. This ismore » the sixth NLSy1 detected at high significance by Fermi-LAT so far. Notably, a significant increase of activity was observed in γ-rays from FBQS J1644+2619 during 2012 July–October, and an increase of activity in V -band was detected by the Catalina Real-Time Sky Survey in the same period.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhattacharyya, B.; Roy, J.; Gupta, Y.

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 themore » 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.« less

The first γ-ray detection of the narrow-line Seyfert 1 FBQS J1644+2619

NASA Astrophysics Data System (ADS)

D'Ammando, F.; Orienti, M.; Larsson, J.; Giroletti, M.

2015-09-01

We report the discovery of γ-ray emission from the narrow-line Seyfert 1 (NLSy1) galaxy FBQS J1644+2619 by the Large Area Telescope on board the Fermi satellite. The Third Fermi LAT Source catalogue reports an unidentified γ-ray source, detected over the first four years of Fermi operation, 0.23° from the radio position of the NLSy1. Analysing 76 months of γ-ray data (2008 August 4-2014 December 31) we are able to better constrain the localization of the γ-ray source. The new position of the γ-ray source is 0.05° from FBQS J1644+2619, suggesting a spatial association with the NLSy1. This is the sixth NLSy1 detected at high significance by Fermi-LAT so far. Notably, a significant increase of activity was observed in γ-rays from FBQS J1644+2619 during 2012 July-October, and an increase of activity in the V band was detected by the Catalina Real-Time Sky Survey in the same period.

Initial characterization of unidentified Armillaria isolate from Serbia using LSU-IGS1 and TEF-1a genes

Treesearch

N. Keca; N. B. Klopfenstein; M.-S. Kim; H. Solheim; S. Woodward

2014-01-01

Armillaria species have a global distribution and play variable ecological roles, including causing root disease of diverse forest, ornamental and horticultural trees. Accurate identification of Armillaria species is critical to understand their distribution and ecological roles. This work focused on characterizing an unidentified Armillaria isolate from a Serbian...

COMPONENT-BASED AND WHOLE-MIXTURE ASSESSMENTS IN ADDRESSING THE UNIDENTIFIED FRACTION OF COMPLEX MIXTURES: DRINKING WATER AS AN EXAMPLE

EPA Science Inventory

Component-Based and Whole-Mixtures Assessments in Addressing the Unidentified Fraction of Complex Mixtures: Drinking Water as an Example

J. E. Simmons; L. K. Teuschler; C. Gennings; T. F. Speth; S. D. Richardson; R. J. Miltner; M. G. Narotsky; K. D. Schenck; G. Rice

12. UNIDENTIFIED CABLESTAYED SUSPENSION BRIDGE WITH TIMBER RAILING OF TWELVE ...

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

12. UNIDENTIFIED CABLE-STAYED SUSPENSION BRIDGE WITH TIMBER RAILING OF TWELVE PANELS, SHOWING CABLE PATTERN SIMILAR TO E.E. RUNYON'S SUSPENSION BRIDGE PATENTS. THE BLUFF DALE SUSPENSION BRIDGE'S CABLES MAY HAVE ORIGINALLY FOLLOWED THIS PATTERN. 3/4 VIEW FROM ABOVE. - Bluff Dale Suspension Bridge, Spanning Paluxy River at County Route 149, Bluff Dale, Erath County, TX

Scanning electron microscopy description of a new species of Demodex canis spp.

PubMed

Tamura, Y; Kawamura, Y; Inoue, I; Ishino, S

2001-10-01

Between 1997 and 1999, the prevalence of Demodex canis mites was determined in 150 dogs. In two dogs, we found two different species of mites; Demodex canis and another, unidentified, Demodex mite. The unidentified Demodex mite species had several different morphological features. First, it had a short opisthosoma and an obtuse end. In addition, the fourth coxisternal plate was rectangular and there was a band-like segmental plate between the fourth coxisternal plate and opisthosoma. Although all of the morphology and the development of male mites could not be investigated in this study, the location of the opisthosoma and the genital pore clearly differed from Demodex canis, suggesting that this unidentified mite is a new species.

KSC-2011-1020

NASA Image and Video Library

2011-01-05

CAPE CANAVERAL, Fla. -- A snowy egret wades through brackish water just north of the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. This type of bird often stalks its prey in shallow water by running or shuffling its feet, flushing small fish, shrimp, frogs or crabs into view. Kennedy coexists with the Merritt Island National Wildlife Refuge, habitat to more than 310 species of birds, 25 mammals, 117 fish and 65 amphibians and reptiles. Photo credit: NASA/Frankie Martin

A Red-Tailed Hawk perches on a stump at KSC.

NASA Technical Reports Server (NTRS)

2000-01-01

This red-tailed hawk on the roadside at Kennedy Space Center appears to be eyeing the photographer. The red-tailed hawk has a stocky build and broad, rounded wings. Its wide range covers Alaska and Nova Scotia south to Panama. It can frequently be seen perched in a tree at the edge of a meadow, watching for movement in the grass below. It feeds mainly on small rodents. The Refuge encompasses 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects. Kennedy Space Center shares a boundary with the Merritt Island National Wildlife Refuge, encompassing 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects.

A Red-Tailed Hawk perches on a stump at KSC.

NASA Technical Reports Server (NTRS)

2000-01-01

Near a road at Kennedy Space Center, a red-tailed hawk perches on a weathered tree stump. The red-tailed hawk has a stocky build and broad, rounded wings. Its broad range covers Alaska and Nova Scotia south to Panama. It can frequently be seen perched in a tree at the edge of a meadow, watching for movement in the grass below. It feeds mainly on small rodents. The Refuge encompasses 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects. Kennedy Space Center shares a boundary with the Merritt Island National Wildlife Refuge, encompassing 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects.

KENNEDY SPACE CENTER, FLA. -- Three male and one female hooded mergansers swim in the quicksilver water of the Merritt Island National Wildlife Refuge, which shares a boundary with Kennedy Space Center. Usually found from Alaska and Canada south to Nebraska, Oregon and Tennessee, hooded mergansers winter south to Mexico and the Gulf Coast, including KSC. The open water of the refuge provides wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds. The 92,000-acre refuge is also habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles.

NASA Image and Video Library

2004-01-08

KENNEDY SPACE CENTER, FLA. -- Three male and one female hooded mergansers swim in the quicksilver water of the Merritt Island National Wildlife Refuge, which shares a boundary with Kennedy Space Center. Usually found from Alaska and Canada south to Nebraska, Oregon and Tennessee, hooded mergansers winter south to Mexico and the Gulf Coast, including KSC. The open water of the refuge provides wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds. The 92,000-acre refuge is also habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles.

The remarkable infrared galaxy Arp 220 = IC 4553

NASA Technical Reports Server (NTRS)

Soifer, B. T.; Neugebauer, G.; Helou, G.; Lonsdale, C. J.; Hacking, P.; Rice, W.; Houck, J. R.; Low, F. J.; Rowan-Robinson, M.

1984-01-01

IRAS observations of the peculiar galaxy Arp 220 = IC 4553 show that it is extremely luminous in the far-infrared, with a total luminosity of 2 x 10 to the 12th solar luminosities. The infrared-to-blue luminosity ratio of this galaxy is about 80, which is the largest value of the ratio for galaxies in the UGC catalog, and places it in the range of the 'unidentified' infrared sources recently reported by Houck et al. in the IRAS all-sky survey. Other observations of Arp 220, combined with the luminosity in the infrared, allow either a Seyfert-like or starburst origin for this luminosity.

Giant molecular clouds as regions of particle acceleration

NASA Technical Reports Server (NTRS)

Dogiel, V. A.; Gurevich, A. V.; Istomin, Y. N.; Zybin, K. A.

1985-01-01

One of the most interesting results of investigations carried out on the satellites SAS-II and COS-B is the discovery of unidentified discrete gamma sources. Possibly a considerable part of them may well be giant molecular clouds. Gamma emission from clouds is caused by the processes with participation of cosmic rays. The estimation of the cosmic ray density in clouds has shown that for the energy E approx. = I GeV their density can 10 to 1000 times exceed the one in intercloud space. We have made an attempt to determine the mechanism which could lead to the increase in the cosmic ray density in clouds.

Diagnosis of gastrointestinal bleeding: A practical guide for clinicians

PubMed Central

Kim, Bong Sik Matthew; Li, Bob T; Engel, Alexander; Samra, Jaswinder S; Clarke, Stephen; Norton, Ian D; Li, Angela E

2014-01-01

Gastrointestinal bleeding is a common problem encountered in the emergency department and in the primary care setting. Acute or overt gastrointestinal bleeding is visible in the form of hematemesis, melena or hematochezia. Chronic or occult gastrointestinal bleeding is not apparent to the patient and usually presents as positive fecal occult blood or iron deficiency anemia. Obscure gastrointestinal bleeding is recurrent bleeding when the source remains unidentified after upper endoscopy and colonoscopic evaluation and is usually from the small intestine. Accurate clinical diagnosis is crucial and guides definitive investigations and interventions. This review summarizes the overall diagnostic approach to gastrointestinal bleeding and provides a practical guide for clinicians. PMID:25400991

Thielavin B methyl ester: a cytotoxic benzoate trimer from an unidentified fungus (MSX 55526) from the Order Sordariales.

PubMed

Ayers, Sloan; Ehrmann, Brandie M; Adcock, Audrey F; Kroll, David J; Wani, Mansukh C; Pearce, Cedric J; Oberlies, Nicholas H

2011-11-02

As part of our ongoing investigation of filamentous fungi for anticancer leads, an active fungal extract was identified from the Mycosynthetix library (MSX 55526; from the Order Sordariales). Bioactivity-directed fractionation yielded the known ergosterol peroxide (2) and 5α,8α-epidioxyergosta-6,9(11),22-trien-3β-ol(3), and a new benzoate trimer, termed thielavin B methyl ester (1). The structure elucidation of 1 was facilitated by the use of HRMS coupled to an APPI (atmospheric pressure photoionization) source. Compound 1 proved to be moderately active against a panel of three cancer cell lines.

A new worm infiltrating the human cornea: A report of three cases.

PubMed

McBurney-Lin, Shan; Khorram, David; Gee, Stephen; Hoberg, Eric P; Klassen-Fischer, Mary K; Neafie, Ronald C

2018-03-01

To characterize a new species of parasitic nematode that triggers uveitis. Three previously healthy, relatively young people each contracted a corneal stromal nematode that, upon surgical removal and examination, did not match any known nematodes. Clinical ocular findings included corneal opacification, visible corneal worms, conjunctival injection, and uveitis. The three cases presented here represent a previously undescribed parasitic infection of the cornea by an unidentified nematode. These findings may represent a previously unrecognized zoonotic infection from wildlife sources and potentially a newly documented nematode requiring description. Future clinical findings regarding this newly described nematode are needed to further develop our understanding of the disease.

Recent Results on SNRs and PWNe from the Fermi Large Area Telescope

NASA Technical Reports Server (NTRS)

Hays, Elizabeth

2010-01-01

Topics include: Fermi LAT Collaboration groups; galactic results from LAT; a GeV, wide-field instrument; the 1FGL catalog, the Fermi LAT 1FGL source catalog, unidentified gamma-ray sources; variability in 1FGL sources; curvature in 1FGL sources; spectral-variability classification; pulsars and their wind nebulae; gamma-ray pulsars and MSPs; GeV PWN search; Crab pulsar and nebula; Vela X nebular of Vela pulsar; MSH 15-52; supernova remnants, resolved GeV sources, galactic transients, LAT unassociated transient detections; gamma rays from a nova; V407 Cyngi - a symbiotic nova; V407 Cygni: a variable star; and March 11 - a nova. Summary slides include pulsars everywhere, blazars, LAT as an electron detector, cosmic ray spectrum, the Large Area Telescope, the Fermi Observatory, LAT sensitivity with time, candidate gamma-ray events, on-orbit energy calibration and rate, a 1 year sky map, LAT automated science processing, reported GeV flares, early activity and spectacular flare, gamma-ray transients near the galactic plane , two early unassociated transients, counter part search - Fermi J0910-5404; counterpart search 3EG J0903-3531, and a new LAT transient - J1057-6027.

MX Siting Investigation. DTN/OBTS Field Surveys. Volume III. Biological Resources Nevada and Utah.

DTIC Science & Technology

1981-11-30

Black - throated sparrow (Amphispiza bilineata) X X X REPTILES Desert tortoise (Gopherus agassizi) X X Zebra-tailed...observed on the greatest number of sites was the black - throated sparrow (Amphispiza bilineata). The reptile most frequently observed was the side-blotched...Poliopt~ila caerula Loggerhead shrike Lanius ludovicianus Black - throated sparrow Amphispiza bilineata Unidentified sparrow Unidentified buteo REPTILES

Genomics dataset of unidentified disclosed isolates.

PubMed

Rekadwad, Bhagwan N

2016-09-01

Analysis of DNA sequences is necessary for higher hierarchical classification of the organisms. It gives clues about the characteristics of organisms and their taxonomic position. This dataset is chosen to find complexities in the unidentified DNA in the disclosed patents. A total of 17 unidentified DNA sequences were thoroughly analyzed. The quick response codes were generated. AT/GC content of the DNA sequences analysis was carried out. The QR is helpful for quick identification of isolates. AT/GC content is helpful for studying their stability at different temperatures. Additionally, a dataset on cleavage code and enzyme code studied under the restriction digestion study, which helpful for performing studies using short DNA sequences was reported. The dataset disclosed here is the new revelatory data for exploration of unique DNA sequences for evaluation, identification, comparison and analysis.

An unusual autopsy case of pyogenic liver abscess caused by periodontal bacteria.

PubMed

Ohyama, Hideki; Nakasho, Keiji; Yamanegi, Koji; Noiri, Yuichiro; Kuhara, Ayako; Kato-Kogoe, Nahoko; Yamada, Naoko; Hata, Masaki; Nishimura, Fusanori; Ebisu, Shigeyuki; Terada, Nobuyuki

2009-09-01

Pyogenic liver abscess (PLA) formation is thought to originate from the transmission of infection via three major routes including the biliary tract, portal vein and hepatic artery. However, about 50% of PLA cases are considered to be cryptogenic. Here we report an unusual autopsy case of PLA associated with periodontopathic bacterial infection. A 59-year-old female suddenly developed cardiopulmonary arrest and died. Despite macroscopic and microscopic examinations, the infectious routes and source of infection were unidentified, and the case appeared to be cryptogenic. Since this patient had suffered severe periodontitis for a long period of time, we investigated the involvement of periodontal infection in PLA formation by performing immunohistochemical analyses. We identified several periodontopathic bacterial species in the PLA of this patient, including Fusobacterium nucleatum, Treponema denticola, Prevotella intermedia and Porphyromonas gingivalis. Thus, we demonstrate here that periodontal infection is a potential source of infection in the formation of PLA.

ScanRanker: Quality Assessment of Tandem Mass Spectra via Sequence Tagging

PubMed Central

Ma, Ze-Qiang; Chambers, Matthew C.; Ham, Amy-Joan L.; Cheek, Kristin L.; Whitwell, Corbin W.; Aerni, Hans-Rudolf; Schilling, Birgit; Miller, Aaron W.; Caprioli, Richard M.; Tabb, David L.

2011-01-01

In shotgun proteomics, protein identification by tandem mass spectrometry relies on bioinformatics tools. Despite recent improvements in identification algorithms, a significant number of high quality spectra remain unidentified for various reasons. Here we present ScanRanker, an open-source tool that evaluates the quality of tandem mass spectra via sequence tagging with reliable performance in data from different instruments. The superior performance of ScanRanker enables it not only to find unassigned high quality spectra that evade identification through database search, but also to select spectra for de novo sequencing and cross-linking analysis. In addition, we demonstrate that the distribution of ScanRanker scores predicts the richness of identifiable spectra among multiple LC-MS/MS runs in an experiment, and ScanRanker scores assist the process of peptide assignment validation to increase confident spectrum identifications. The source code and executable versions of ScanRanker are available from http://fenchurch.mc.vanderbilt.edu. PMID:21520941

Observations of a high-excitation transition of SO in galactic H II regions

NASA Astrophysics Data System (ADS)

Watt, G. D.; Millar, T. J.; White, G. J.; Harten, R. H.

1986-02-01

High-excitation observations of the 56-45 transition of SO at 251 GHz have been made. The central four arcminutes of the Orion-KL region have been mapped and a survey of 6 other galactic sources has been performed. Detailed chemical kinetic models have been utilised to investigate the chemistry of sulphur in view of recent estimates of sulphur depletion and the possibility of a gas phase carbon to oxygen ratio greater than 1. The authors find a link between the SO/SO2 and C/O ratios and that their data are consistent with the high C I abundance detected in the Orion ridge component. In the plateau source the enhanced abundances of SO and SO2 may be caused by a molecular outflow from an oxygen-rich star. In addition a previously undetected methanol line and an unidentified line appear in the Orion data.

VizieR Online Data Catalog: A survey for Hα pulsar bow shocks (Brownsberger+, 2014)

NASA Astrophysics Data System (ADS)

Brownsberger, S.; Romani, R. W.

2017-06-01

Our pulsar Hα campaign was pursued during a series of WIYN and SOAR observations, allocated through the joint Fermi/NOAO program to study the counterparts of LAT pulsar, blazar, and unidentified sources. The PWN data reported here came from portions of five observing runs, covering both the Northern and Southern hemispheres. For all Hα images we used the WIYN W012 (λ=6566 Å, ΔλFWHM=16 Å) narrow band Hα filter, kindly loaned to SOAR for the two southern campaigns. To help distinguish poorly resolved Hα sources near the pulsars from stars, we also obtained, when possible, matching continuum observations using the W014 (λ=6562 Å, ΔλFWHM=378 Å) wide Hα filter or a Sloan Digital Sky Survey (SDSS) r'(λ=6163 Å, ΔλFWHM=1518 Å) broad band filter. (1 data file).

A complete X-ray sample of the high latitude sky from HEAO-1 A-2: log N lo S and luminosity functions

NASA Technical Reports Server (NTRS)

Piccinotti, G.; Mushotzky, R. F.; Boldt, E. A.; Holt, S. S.; Marshall, F. E.; Serlemitsos, P. J.; Shafer, R. A.

1981-01-01

An experiment was performed in which a complete X-ray survey of the 8.2 steradians of the sky at galactic latitudes where the absolute value of b is 20 deg down to a limiting sensitivity of 3.1 x ten to the minus 11th power ergs/sq cm sec in the 2-10 keV band. Of the 85 detected sources 17 were identified with galactic objects, 61 were identified with extragalactic objects, and 7 remain unidentified. The log N - log S relation for the non-galactic objects is well fit by the Euclidean relationship. The X-ray spectra of these objects were used to construct log N - log S in physical units. The complete sample of identified sources was used to construct X-ray luminosity functions, using the absolute maximum likelihood method, for clusters galaxies and active galactic nuclei.

Landscape Epidemiology of Tularemia Outbreaks in Sweden

PubMed Central

Svensson, Kerstin; Bäck, Erik; Eliasson, Henrik; Berglund, Lennart; Granberg, Malin; Karlsson, Linda; Larsson, Pär; Forsman, Mats

2009-01-01

Summer outbreaks of tularemia that occurred from 1995 through 2005 in 2 locations in Sweden affected 441 persons. We performed an epidemiologic investigation of these outbreaks using a novel strategy, involving high-resolution genotyping of Francisella tularensis isolates obtained from 136 patients (using 18 genetic markers developed from 6 F. tularensis genome sequences) and interviews with the patients. Strong spatial associations were found between F. tularensis subpopulations and the places of disease transmission; infection by some subpopulations occurred within areas as small as 2 km2, indicating unidentified environmental point sources of tularemia. In both locations, disease clusters were associated with recreational areas beside water, and genetic subpopulations were present throughout the tularemia season and persisted over years. High-resolution genotyping in combination with patients’ statements about geographic places of disease transmission provided valuable indications of likely sources of infection and the causal genotypes during these tularemia outbreaks. PMID:19961673

Wildlife Photography - Birds

NASA Image and Video Library

2017-12-14

Seagulls gather along a shoreline at NASA's Kennedy Space Center in Florida. Kennedy shares a boundary with the Merritt Island National Wildlife Refuge. The refuge encompasses 140,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fish, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

Wildlife Photography - Birds

NASA Image and Video Library

2017-12-14

A wild turkey is seen at NASA's Kennedy Space Center in Florida. Kennedy shares a boundary with the Merritt Island National Wildlife Refuge. The refuge encompasses 140,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fish, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

Wildlife Photography - Birds

NASA Image and Video Library

2017-12-14

Ducks gather in a waterway at NASA's Kennedy Space Center in Florida. Kennedy shares a boundary with the Merritt Island National Wildlife Refuge. The refuge encompasses 140,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fish, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

Discovery touches down after successful mission STS-95

NASA Technical Reports Server (NTRS)

1998-01-01

Orbiter Discovery startles a great white egret next to runway 33 as it touches down at the Shuttle Landing Facility. Discovery returns to Earth with its crew of seven after a successful mission STS-95 lasting nearly nine days and 3.6 million miles. The mission included research payloads such as the Spartan solar- observing deployable spacecraft, the Hubble Space Telescope Orbital Systems Test Platform, the International Extreme Ultraviolet Hitchhiker, as well as the SPACEHAB single module with experiments on space flight and the aging process.

System design of a remotely operated, program controlled measurement table for the calibration of the Egret experiment. Part A: Program control

NASA Technical Reports Server (NTRS)

1984-01-01

The structure of the program, the five priority levels, the drive routines, the stepwise drive plan, the figure routines, meander X and y, the range of measurement table, the optimization of figure drive, the figure drive plan, dialogue routines, stack processing, the drive for the main terminal, the protocol routines, the drive for the microterminal, the drive for the experiment computer, and the main program are discussed.

KSC-2014-2925

NASA Image and Video Library

2014-06-13

CAPE CANAVERAL, Fla. -- This great egret may be trying to hide in the tall grass on NASA's Kennedy Space Center in Florida to conceal the fact that it is molting. The undeveloped property on Kennedy Space Center is managed by the U.S. Fish and Wildlife Service through the Merritt Island National Wildlife Refuge. The refuge provides a habitat for a plethora of wildlife, including 330 species of birds. For information on the refuge, visit http://www.fws.gov/merrittisland/Index.html. Photo credit: NASA/Daniel Casper

KSC-99pc0106

NASA Image and Video Library

1999-01-21

KENNEDY SPACE CENTER, FLA. -- A flock of ducks launch into the morning sky in the Merritt Island National Wildlife Refuge at Kennedy Space Center. The open water of the refuge provides wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds. The 92,000-acre refuge is also habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles

Ducks launch into flight at KSC

NASA Technical Reports Server (NTRS)

1999-01-01

A flock of ducks launch into the morning sky in the Merritt Island National Wildlife Refuge at Kennedy Space Center. The open water of the refuge provides wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds. The 92,000-acre refuge is also habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles.

KSC-03PD-2986

NASA Technical Reports Server (NTRS)

2003-01-01

KENNEDY SPACE CENTER, FLA. Two blue-winged teals swim in a pond near KSC. The species prefers marshes and shallow ponds and lakes for nesting and range from Canada to North Carolina, the Gulf Coast and Southern California, as well as Florida. KSC shares a boundary with the National Merritt Island Wildlife Refuge, which provides wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

An X-Ray Counterpart of HESS J1427-608 Discovered with Suzaku

NASA Astrophysics Data System (ADS)

Fujinaga, Takahisa; Mori, Koji; Bamba, Aya; Kimura, Shoichi; Dotani, Tadayasu; Ozaki, Masanobu; Matsuta, Keiko; Pülhofer, Gerd; Uchiyama, Hideki; Hiraga, Junko S.; Matsumoto, Hironori; Terada, Yukikatsu

2013-06-01

We report on the discovery of an X-ray counterpart of the unidentified very high-energy gamma-ray source HESS J1427-608. In the sky field coincident with HESS J1427-608, an extended source was found in the 2-8 keV band, and was designated as Suzaku J1427-6051. Its X-ray radial profile has an extension of σ = 0.'9 ± 0.'1 if approximated by a Gaussian. The spectrum was well fitted by an absorbed power-law with NH = (1.1 ± 0.3) × 1023 cm-2, Γ = 3.1+0.6-0.5, and the unabsorbed flux FX = (9+4-2) × 10-13 erg s-1 cm-2 in the 2-10 keV band. Using XMM-Newton archive data, we found seven point sources in the Suzaku source region. However, because their total flux and absorbing column densities are more than an order of magnitude lower than those of Suzaku J1427-6051, we consider that they are unrelated to the Suzaku source. Thus, Suzaku J1427-6051 is considered to be a truly diffuse source and an X-ray counterpart of HESS J1427-608. The possible nature of HESS J1427-608 is discussed based on the observational properties.

Cloning and Characterizing Genes Involved in Monoterpene Induced Mammary Tumor Regression

DTIC Science & Technology

1998-05-01

Monoterpene -induced/repressed genes were identified in regressing rat mammary carcinomas treated with dietary limonene using a newly developed method...termed subtractive display. The subtractive display screen identified 42 monoterpene -induced genes comprising 9 known genes and 33 unidentified genes...as well as 58 monoterpene -repressed genes comprising 1 known gene and 57 unidentified genes. Several of the identified differentially expressed

Blood biomarkers and contaminant levels in feathers and eggs to assess environmental hazards in heron nestlings from impacted sites in Ebro basin (NE Spain).

PubMed

Barata, C; Fabregat, M C; Cotín, J; Huertas, D; Solé, M; Quirós, L; Sanpera, C; Jover, L; Ruiz, X; Grimalt, J O; Piña, B

2010-03-01

Blood biomarkers and levels of major pollutants in eggs and feathers were used to determine pollution effects in nestlings of the Purple Heron Ardea purpurea and the Little Egret Egretta garzetta, sampled on three Ebro River (NE Spain) areas: a reference site, a site affected by the effluents of a chlor-alkali industry and the river Delta. The two impacted heron populations showed mutually different pollutant and response patterns, suggesting different sources of contamination. In the population nesting near the chlor-alkali plant, elevated levels of hexachlorobenzene (HCB) and polychlorobiphenyls (PCBs) in eggs, and mercury in feathers in A. purpurea chicks were related with reduced blood antioxidant defenses and increased levels of micronuclei. In Ebro Delta, high levels of plasmatic lactate dehydrogenase in A. purpurea chicks and high frequency of micronuclei in blood of both species were tentatively associated with intensive agricultural activities taking place in the area. These results provide the first evidence of a biological response in heron chicks to the release of pollutants at a chlor-alkali plant. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Can the bump in the composite spectrum of GRB 910503 be an emission line feature of gamma-ray bursts?

NASA Astrophysics Data System (ADS)

Qin, Yi-Ping; Zhang, Fu-Wen

2005-12-01

Appearing in the composite spectral data of BATSE, EGRET and COMPTEL for GRB 910503, there is a bump at around 1600 keV. We perform a statistical analysis on the spectral data, trying to find out if the bump could be accounted for by a blue-shifted and significantly broadened rest frame line due to the Doppler effect of an expanding fireball surface. We made an F-test and adopted previously proposed criteria. The study reveals that the criteria are well satisfied and the feature can be interpreted as the blue shifted 6.4 keV line. From the fit with this line taken into account, we find the Lorentz factor of this source to be Γ = 116+9-9 (at the 68% confident level, triangleχ2 = 1) and the rest frame spectral peak energy to be E0,p = 2.96+0.24-0.18 keV. Although the existence of the emission line feature requires other independent tests to confirm, the analysis suggests that it is feasible to detect emission line features in the high energy range of GRB spectra when taking into account the Doppler effect of fireball expansion.

AGN jets as pion factories

NASA Astrophysics Data System (ADS)

Mannheim, Karl

There has been a dramatic revolution in gamma-ray astronomy throughout the last few years. Beginning with the discovery made by the spark chamber EGRET on board the Compton Gamma Ray Observatory that AGN with jets are the most powerful quasi-steady gamma-ray sources in the Universe, air-Cerenkov telescopes have soon after succeeded in detecting gamma-rays up to TeV energies. In the last year, it has become clear that these AGN emit photons even up to 10 TeV and more. This is a strong indication for proton acceleration going on in them, since protons owing to their large mass suffer weaker energy losses than electrons and can thus reach higher energies. Nucleons escaping from the AGN jets contribute to the local flux of cosmic rays at highest energies. If AGN produce the diffuse gamma-ray background, they would also be able to produce all the cosmic rays above the ankle in the local spectrum. The majority of AGN resides at large distances, indicated by their cosmological redshifts, and can therefore not be seen through the fog of electron-positron pairs which they produce interacting with diffuse infrared radiation from the era of galaxy formation. To observe the cosmic accelerators at large redshifts, neutrino observations are required. It is important to understand the astrophysical neutrino sources in order to be able to recognize signatures of new physics, e.g. due to decaying or annihilating particles from the early phases of the Universe.

Identification of γ-ray emission from 3C 345 and NRAO 512

DOE PAGES

Schinzel, F. K.; Sokolovsky, K. V.; D’Ammando, F.; ...

2011-08-09

For more than 15 years, since the days of the Energetic Gamma-Ray Experiment Telescope (EGRET) on board the Compton Gamma-Ray Observatory (CGRO; 1991–2000), it has remained an open question why the prominent blazar 3C 345 was not reliably detected at γ-ray energies ≥ 20 MeV. Recently a bright γ-ray source (0FGL J1641.4+3939/1FGL J1642.5+3947), potentially associated with 3C 345, was detected by the Large Area Telescope (LAT) on Fermi. Multiwavelength observations from radio bands to X-rays (mainly GASP-WEBT and Swift) of possible counterparts (3C 345, NRAO 512, B3 1640 + 396) were combined with 20 months of Fermi-LAT monitoring data (Augustmore » 2008 – April 2010) to associate and identify the dominating γ-ray emitting counterpart of 1FGL J1642.5+3947. The source 3C 345 is identified as the main contributor for this γ-ray emitting region. However, after November 2009 (15 months), a significant excess of photons from the nearby quasar NRAO 512 started to contribute and thereafter was detected with increasing γ-ray activity, possibly adding flux to 1FGL J1642.5+3947. As a result, for the same time period and during the summer of 2010, an increase of radio, optical and X-ray activity of NRAO 512 was observed. No γ-ray emission from B3 1640 + 396 was detected.« less

First light from the Vela pulsar with the Fermi Gamma-ray Space Telescope

NASA Astrophysics Data System (ADS)

Razzano, M.

2009-04-01

The Fermi Gamma-ray Space Telescope, launched in June 2008, is an international space mission entirely devoted to the study of the high-energy gamma rays from the Universe. The main instrument aboard Fermi is the Large Area Telescope (LAT), a pair conversion telescope equipped with the state-of-the art in gamma-ray detectors technology. Thanks to its large field of view and effective area, combined with its excellent timing capability, Fermi-LAT is a perfect instrument for probing physics of gamma-ray emission in pulsars. LAT is expected to discover tens of new pulsars, both radio-loud and radio-quiet (Geminga-like). Moreover, LAT will observe with unprecedented statistics the brightest pulsars, investigating the details of magnetospheric emission. The first two months of the mission have been focused on the commissioning and first light, during which the LAT firmly detected the six previously known EGRET gamma-ray pulsars. One of the main sources of interest during our first light observations has been the Vela pulsar, the brightest persistent source in the whole gamma-ray sky. Thanks to its brightness, the Vela pulsar is an ideal candidate for calibrating the LAT and testing its performance. In addition, observations of Vela will help answer many questions related to the physics of pulsar emission processes. We present here some recent results obtained by the LAT on the Vela pulsar, using high-quality timing solutions provided by radio observations carried out within the Fermi pulsar radio timing campaign.

Structural Identifiability of Dynamic Systems Biology Models

PubMed Central

Villaverde, Alejandro F.

2016-01-01

A powerful way of gaining insight into biological systems is by creating a nonlinear differential equation model, which usually contains many unknown parameters. Such a model is called structurally identifiable if it is possible to determine the values of its parameters from measurements of the model outputs. Structural identifiability is a prerequisite for parameter estimation, and should be assessed before exploiting a model. However, this analysis is seldom performed due to the high computational cost involved in the necessary symbolic calculations, which quickly becomes prohibitive as the problem size increases. In this paper we show how to analyse the structural identifiability of a very general class of nonlinear models by extending methods originally developed for studying observability. We present results about models whose identifiability had not been previously determined, report unidentifiabilities that had not been found before, and show how to modify those unidentifiable models to make them identifiable. This method helps prevent problems caused by lack of identifiability analysis, which can compromise the success of tasks such as experiment design, parameter estimation, and model-based optimization. The procedure is called STRIKE-GOLDD (STRuctural Identifiability taKen as Extended-Generalized Observability with Lie Derivatives and Decomposition), and it is implemented in a MATLAB toolbox which is available as open source software. The broad applicability of this approach facilitates the analysis of the increasingly complex models used in systems biology and other areas. PMID:27792726

LC/QTOF-MS fragmentation of N-nitrosodimethylamine precursors in drinking water supplies is predictable and aids their identification.

PubMed

Hanigan, David; Ferrer, Imma; Thurman, E Michael; Herckes, Pierre; Westerhoff, Paul

2017-02-05

N-Nitrosodimethylamine (NDMA) is carcinogenic in rodents and occurs in chloraminated drinking water and wastewater effluents. NDMA forms via reactions between chloramines and mostly unidentified, N-containing organic matter. We developed a mass spectrometry technique to identify NDMA precursors by analyzing 25 model compounds with LC/QTOF-MS. We searched isolates of 11 drinking water sources and 1 wastewater using a custom MATLAB ® program and extracted ion chromatograms for two fragmentation patterns that were specific to the model compounds. Once a diagnostic fragment was discovered, we conducted MS/MS during a subsequent injection to confirm the precursor ion. Using non-target searches and two diagnostic fragmentation patterns, we discovered 158 potential NDMA precursors. Of these, 16 were identified using accurate mass combined with fragment and retention time matches of analytical standards when available. Five of these sixteen NDMA precursors were previously unidentified in the literature, three of which were metabolites of pharmaceuticals. Except methadone, the newly identified precursors all had NDMA molar yields of less than 5%, indicating that NDMA formation could be additive from multiple compounds, each with low yield. We demonstrate that the method is applicable to other disinfection by-product precursors by predicting and verifying the fragmentation patterns for one nitrosodiethylamine precursor. Copyright © 2016. Published by Elsevier B.V.

Development of unidentified dna-specific hif 1α gene of lizard (hemidactylus platyurus) which plays a role in tissue regeneration process

NASA Astrophysics Data System (ADS)

Novianti, T.; Sadikin, M.; Widia, S.; Juniantito, V.; Arida, E. A.

2018-03-01

Development of unidentified specific gene is essential to analyze the availability these genes in biological process. Identification unidentified specific DNA of HIF 1α genes is important to analyze their contribution in tissue regeneration process in lizard tail (Hemidactylus platyurus). Bioinformatics and PCR techniques are relatively an easier method to identify an unidentified gene. The most widely used method is BLAST (Basic Local Alignment Sequence Tools) method for alignment the sequences from the other organism. BLAST technique is online software from website https://blast.ncbi.nlm.nih.gov/Blast.cgi that capable to generate the similar sequences from closest kinship to distant kindship. Gecko japonicus is a species that it has closest kinship with H. platyurus. Comparing HIF 1 α gene sequence of G. japonicus with the other species used multiple alignment methods from Mega7 software. Conserved base areas were identified using Clustal IX method. Primary DNA of HIF 1 α gene was design by Primer3 software. HIF 1α gene of lizard (H. platyurus) was successfully amplified using a real-time PCR machine by primary DNA that we had designed from Gecko japonicus. Identification unidentified gene of HIF 1a lizard has been done successfully with multiple alignment method. The study was conducted by analyzing during the growth of tail on day 1, 3, 5, 7, 10, 13 and 17 of lizard tail after autotomy. Process amplification of HIF 1α gene was described by CT value in real time PCR machine. HIF 1α expression of gene is quantified by Livak formula. Chi-square statistic test is 0.000 which means that there is a different expression of HIF 1 α gene in every growth day treatment.

Nitrous acid formation in a snow-free wintertime polluted rural area

NASA Astrophysics Data System (ADS)

Tsai, Catalina; Spolaor, Max; Fedele Colosimo, Santo; Pikelnaya, Olga; Cheung, Ross; Williams, Eric; Gilman, Jessica B.; Lerner, Brian M.; Zamora, Robert J.; Warneke, Carsten; Roberts, James M.; Ahmadov, Ravan; de Gouw, Joost; Bates, Timothy; Quinn, Patricia K.; Stutz, Jochen

2018-02-01

Nitrous acid (HONO) photolysis is an important source of hydroxyl radicals (OH) in the lower atmosphere, in particular in winter when other OH sources are less efficient. The nighttime formation of HONO and its photolysis in the early morning have long been recognized as an important contributor to the OH budget in polluted environments. Over the past few decades it has become clear that the formation of HONO during the day is an even larger contributor to the OH budget and additionally provides a pathway to recycle NOx. Despite the recognition of this unidentified HONO daytime source, the precise chemical mechanism remains elusive. A number of mechanisms have been proposed, including gas-phase, aerosol, and ground surface processes, to explain the elevated levels of daytime HONO. To identify the likely HONO formation mechanisms in a wintertime polluted rural environment we present LP-DOAS observations of HONO, NO2, and O3 on three absorption paths that cover altitude intervals from 2 to 31, 45, and 68 m above ground level (a.g.l.) during the UBWOS 2012 experiment in the Uintah Basin, Utah, USA. Daytime HONO mixing ratios in the 2-31 m height interval were, on average, 78 ppt, which is lower than HONO levels measured in most polluted urban environments with similar NO2 mixing ratios of 1-2 ppb. HONO surface fluxes at 19 m a.g.l., calculated using the HONO gradients from the LP-DOAS and measured eddy diffusivity coefficient, show clear upward fluxes. The hourly average vertical HONO flux during sunny days followed solar irradiance, with a maximum of (4.9 ± 0.2) × 1010 molec. cm-2 s-1 at noontime. A photostationary state analysis of the HONO budget shows that the surface flux closes the HONO budget, accounting for 63 ± 32 % of the unidentified HONO daytime source throughout the day and 90 ± 30 % near noontime. This is also supported by 1-D chemistry and transport model calculations that include the measured surface flux, thus clearly identifying chemistry at the ground as the missing daytime HONO source in this environment. Comparison between HONO surface flux, solar radiation, NO2 and HNO3 mixing ratios, and results from 1-D model runs suggest that, under high NOx conditions, HONO formation mechanisms related to solar radiation and NO2 mixing ratios, such as photo-enhanced conversion of NO2 on the ground, are most likely the source of daytime HONO. Under moderate to low NO2 conditions, photolysis of HNO3 on the ground seems to be the main source of HONO.

77 FR 32986 - Notice of Inventory Completion: The University of Alabama Museums, Tuscaloosa, AL

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-04

... than 2,032 glass beads, 1 lot of more than 17 shell beads, 1 unidentified bead, 1 gun lock, 1 gun butt plate, 1 gun stock, 2 gun barrels, 1 brass ramrod support, 8 musket balls, 2 iron buckles, 1 iron handle... fragments, 1 unidentified bead, 2 glass beads, 1 gun flint, 1 iron knife blade, 1 iron nail, 1 musket ball...

Bat Virus Downunder: The Hendra Virus and Its Relationship to Native Fruit Bats, Horses and Human --Learning and Teaching Opportunities for Classroom Practice

ERIC Educational Resources Information Center

van Rooy, Wilhelmina

2013-01-01

The fatal effect of the Hendra virus was noticed first in Queensland, Australia in 1994 when several horses died from an "unidentified cause". This was followed by the death of trainers and veterinarians called to assist affected horses. It is now known that the "unidentified cause", is a virus harboured in native Australian…

Supplemental Archeological Investigations of Lower Bayou Teche, St. Mary Parish, Louisiana

DTIC Science & Technology

1991-08-01

Ruler end (brass)1 ____ Buckle 1__________ Brass and inlaid shell button 1____ Chain 2 71 Cosmetic cap - gild brass inlaid with shell 1I____ 185...Molded stemnware fragment ____ _____ _____ Unidentified ______ ______1 Perfume/ Cosmetic Bottle Fragment Milk glass 2 Melted Glass Aqua1 Unidentified...major portion of the recovery (n = 122). Other metal artifacts included 2 safety pins, 1 cosmetic cap made of gilt brass inlaid with shell, 3 buttons

Deinococcus multiflagellatus sp. nov., isolated from a car air-conditioning system.

PubMed

Kim, Dong-Uk; Lee, Hyosun; Lee, Suyeon; Park, Sooyeon; Yoon, Jung-Hoon; Zhao, Lei; Kim, Min-Kyu; Ahn, Jae-Hyung; Ka, Jong-Ok

2018-04-01

A gamma radiation-resistant and pink-to-red pigmented bacterial strain, designated ID1504 T , was isolated from a car air-conditioning system sampled in Korea. The cells were observed to be Gram-stain negative, aerobic, motile with peritrichous flagella and short rod-shaped. Phylogenetically, the strain groups with the members of the genus Deinococcus and exhibits high 16S rRNA gene sequence similarities with Deinococcus arenae SA1 T (94.0%), Deinococcus actinosclerus BM2 T (93.9%) and Deinococcus soli N5 T (93.5%). The predominant fatty acids were identified as C 17:0 , C 16:0 , summed feature 3 (C 16:1 ω7c and/or C 16:1 ω6c) and iso-C 17:0 . The major respiratory quinone was identified as MK-8. The polar lipids were found to be comprised of unidentified phospholipids, unidentified glycolipids, an unidentified aminophospholipid and an unidentified lipid. The DNA G+C content of the strain was determined to be 68.3 mol%. On the basis of the phenotypic, genotypic and chemotaxonomic characteristics, strain ID1504 T should be classified in a novel species in the genus Deinococcus, for which the name Deinococcus multiflagellatus sp. nov. (= KACC 19287 T  = NBRC 112888 T ) is proposed.

Identification of the geographical place of origin of an unidentified individual by multi-isotope analysis.

PubMed

Font, Laura; van der Peijl, Gerard; van Leuwen, Carina; van Wetten, Isis; Davies, Gareth R

2015-01-01

A multi-isotope investigation (Sr and Pb isotopes and δ18O, δ13C and δ15N) was applied to bone and teeth from an unidentified male found drowned in the"IJ" Ruyterkade in Amsterdam, The Netherlands in March of 1999. The individual remained unidentified until mid 2013, after the isotope study was completed. Coupled δ13C and δ15N values in bone collagen recovered from rib and femur are consistent with an omnivore living in a region where C3-type diet dominates (i.e. Europe). Integrated Sr and Pb isotopes and δ18O values in canine and third molar teeth and femur and rib bone data exclude extended residence in north-west Europe and particularly The Netherlands. Characteristic Pb isotope ratios coupled with inferred δ18O values of drinking water argue for a most probable place of origin for the unidentified individual in west and south Poland, south-east Slovakia and the region of Ukraine-Romania-Bulgaria, specifically the region associated with the Carpathian Mountains. Independent of the isotope study, the Cold Case Team made a positive identification with an individual from south-west Poland, validating the results of the multiple-isotopic approach. Copyright © 2014 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

Dark matter subhalos and unidentified sources in the Fermi 3FGL source catalog

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schoonenberg, Djoeke; Gaskins, Jennifer; Bertone, Gianfranco

2016-05-01

If dark matter consists of weakly interacting massive particles (WIMPs), dark matter subhalos in the Milky Way could be detectable as gamma-ray point sources due to WIMP annihilation. In this work, we perform an updated study of the detectability of dark matter subhalos as gamma-ray sources with the Fermi Large Area Telescope (Fermi LAT). We use the results of the Via Lactea II simulation, scaled to the Planck 2015 cosmological parameters, to predict the local dark matter subhalo distribution. Under optimistic assumptions for the WIMP parameters—a 40 GeV particle annihilating to b b-bar with a thermal cross-section, as required tomore » explain the Galactic center GeV excess—we predict that at most ∼ 10 subhalos might be present in the third Fermi LAT source catalog (3FGL). This is a smaller number than has been predicted by prior studies, and we discuss the origin of this difference. We also compare our predictions for the detectability of subhalos with the number of subhalo candidate sources in 3FGL, and derive upper limits on the WIMP annihilation cross-section as a function of the particle mass. If a dark matter interpretation could be excluded for all 3FGL sources, our constraints would be competitive with those found by indirect searches using other targets, such as known Milky Way satellite galaxies.« less

Volumetric Acoustic Vector Intensity Probe

NASA Technical Reports Server (NTRS)

Klos, Jacob

2006-01-01

A new measurement tool capable of imaging the acoustic intensity vector throughout a large volume is discussed. This tool consists of an array of fifty microphones that form a spherical surface of radius 0.2m. A simultaneous measurement of the pressure field across all the microphones provides time-domain near-field holograms. Near-field acoustical holography is used to convert the measured pressure into a volumetric vector intensity field as a function of frequency on a grid of points ranging from the center of the spherical surface to a radius of 0.4m. The volumetric intensity is displayed on three-dimensional plots that are used to locate noise sources outside the volume. There is no restriction on the type of noise source that can be studied. The sphere is mobile and can be moved from location to location to hunt for unidentified noise sources. An experiment inside a Boeing 757 aircraft in flight successfully tested the ability of the array to locate low-noise-excited sources on the fuselage. Reference transducers located on suspected noise source locations can also be used to increase the ability of this device to separate and identify multiple noise sources at a given frequency by using the theory of partial field decomposition. The frequency range of operation is 0 to 1400Hz. This device is ideal for the study of noise sources in commercial and military transportation vehicles in air, on land and underwater.

X-ray astronomy from Uhuru to HEAO-1

NASA Technical Reports Server (NTRS)

Clark, G. W.

1981-01-01

The nature of galactic and extragalactic X-ray sources is investigated using observations made with nine satellites and several rockets. The question of X-ray pulsars being neutron stars or white dwarfs is considered, as is the nature of Population II and low-luminosity X-ray stars, the diffuse X-ray emission from clusters of galaxies, the unidentified high-galactic-latitude (UHGL) sources, and the unresolved soft X-ray background. The types of sources examined include binary pulsars, Population II X-ray stars (both nonbursters and bursters) inside and outside globular clusters, coronal X-ray emitters, and active galactic nuclei. It is concluded that: (1) X-ray pulsars are strongly magnetized neutron stars formed in the evolution of massive close binaries; (2) all Population II X-ray stars are weakly magnetized or nonmagnetic neutron stars accreting from low-mass companions in close binary systems; (3) the diffuse emission from clusters is thermal bremsstrahlung of hot matter processed in stars and swept out by ram pressure exerted by the intergalactic gas; (4) most or all of the UHGL sources are active galactic nuclei; and (5) the soft X-ray background is emission from a hot component of the interstellar medium.

Geophysical variables and behavior: XC. What people consider strange: change in proportions of reports of Fortean phenomena over time.

PubMed

Persinger, M A

2001-02-01

The proportions of 3,667 reports classified as unusual or odd events within eight major categories for four contiguous blocks of time between 1770 and 1970 were compared for disconcordance. The major source of the disconcordance (phi = .52) of reports between the major categories and time was due to the decrease in the numbers of reports of falls of ice, rocks, and animals but increased numbers of reports of odd luminosities, labelled as unidentified flying objects, after the mid 1930s. One hypothesis to explain this result is that cultural changes in attributions for causes of natural phenomena may affect their designation as strange rather than mundane.

Binary millisecond pulsar discovery via gamma-ray pulsations.

PubMed

Pletsch, H J; Guillemot, L; Fehrmann, H; Allen, B; Kramer, M; Aulbert, C; Ackermann, M; Ajello, M; de Angelis, A; Atwood, W B; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Bechtol, K; Bellazzini, R; Borgland, A W; Bottacini, E; Brandt, T J; Bregeon, J; Brigida, M; Bruel, P; Buehler, R; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Cecchi, C; Çelik, Ö; Charles, E; Chaves, R C G; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Conrad, J; Cutini, S; D'Ammando, F; Dermer, C D; Digel, S W; Drell, P S; Drlica-Wagner, A; Dubois, R; Dumora, D; Favuzzi, C; Ferrara, E C; Franckowiak, A; Fukazawa, Y; Fusco, P; Gargano, F; Gehrels, N; Germani, S; Giglietto, N; Giordano, F; Giroletti, M; Godfrey, G; Grenier, I A; Grondin, M-H; Grove, J E; Guiriec, S; Hadasch, D; Hanabata, Y; Harding, A K; den Hartog, P R; Hayashida, M; Hays, E; Hill, A B; Hou, X; Hughes, R E; Jóhannesson, G; Jackson, M S; Jogler, T; Johnson, A S; Johnson, W N; Kataoka, J; Kerr, M; Knödlseder, J; Kuss, M; Lande, J; Larsson, S; Latronico, L; Lemoine-Goumard, M; Longo, F; Loparco, F; Lovellette, M N; Lubrano, P; Massaro, F; Mayer, M; Mazziotta, M N; McEnery, J E; Mehault, J; Michelson, P F; Mitthumsiri, W; Mizuno, T; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nakamori, T; Nemmen, R; Nuss, E; Ohno, M; Ohsugi, T; Omodei, N; Orienti, M; Orlando, E; de Palma, F; Paneque, D; Perkins, J S; Piron, F; Pivato, G; Porter, T A; Rainò, S; Rando, R; Ray, P S; Razzano, M; Reimer, A; Reimer, O; Reposeur, T; Ritz, S; Romani, R W; Romoli, C; Sanchez, D A; Saz Parkinson, P M; Schulz, A; Sgrò, C; do Couto e Silva, E; Siskind, E J; Smith, D A; Spandre, G; Spinelli, P; Suson, D J; Takahashi, H; Tanaka, T; Thayer, J B; Thayer, J G; Thompson, D J; Tibaldo, L; Tinivella, M; Troja, E; Usher, T L; Vandenbroucke, J; Vasileiou, V; Vianello, G; Vitale, V; Waite, A P; Winer, B L; Wood, K S; Wood, M; Yang, Z; Zimmer, S

2012-12-07

Millisecond pulsars, old neutron stars spun up by accreting matter from a companion star, can reach high rotation rates of hundreds of revolutions per second. Until now, all such "recycled" rotation-powered pulsars have been detected by their spin-modulated radio emission. In a computing-intensive blind search of gamma-ray data from the Fermi Large Area Telescope (with partial constraints from optical data), we detected a 2.5-millisecond pulsar, PSR J1311-3430. This unambiguously explains a formerly unidentified gamma-ray source that had been a decade-long enigma, confirming previous conjectures. The pulsar is in a circular orbit with an orbital period of only 93 minutes, the shortest of any spin-powered pulsar binary ever found.

Is the Universe More Transparent to Gamma Rays than Previously Thought?

NASA Technical Reports Server (NTRS)

Stecker, Floyd W.; Scully, Sean T.

2009-01-01

The MAGIC collaboration has recently reported the detection of the strong gamma-ray blazar 3C279 during a 1-2 day flare. They have used their spectral observations to draw conclusions regarding upper limits on the opacity of the Universe to high energy gamma-rays and, by implication, upper limits on the extragalactic mid-infrared background radiation. In this paper we examine the effect of gamma-ray absorption by the extragalactic infrared radiation on intrinsic spectra for this blazar and compare our results with the observational data on 3C279. We find agreement with our previous results, contrary to the recent assertion of the MAGIC group that the Universe is more transparent to gamma-rays than our calculations indicate. Our analysis indicates that in the energy range between approx. 80 and approx. 500 GeV, 3C279 has a best-fit intrinsic spectrum with a spectral index approx. 1.78 using our fast evolution model and approx. 2.19 using our baseline model. However, we also find that spectral indices in the range of 1.0 to 3.0 are almost as equally acceptable as the best fit spectral indices. Assuming the same intrinsic spectral index for this flare as for the 1991 flare from 3C279 observed by EGRET, viz., 2.02, which lies between our best fit indeces, we estimate that the MAGIC flare was approx.3 times brighter than the EGRET flare observed 15 years earlier.

Poplar Island Environmental Restoration Project: Challenges in waterbird restoration on an island in Chesapeake Bay

USGS Publications Warehouse

Erwin, R.M.; Miller, J.; Reese, J.G.

2007-01-01

At 460 hectares, the Paul Sarbanes Environmental Restoration Project at Poplar Island, Talbot County, Maryland, represents the largest 'beneficial use' dredged material project of the U. S. Army Corps of Engineers (a cooperative project with Maryland Port Administration). Begun in 1998, the 15-year restoration project will ultimately consist of roughly 220 ha of uplands and 220 ha of tidal wetland habitats, with limited areas of dike roads, perimeter riprap, and unvegetated mudflats. Wetland restoration began in one small section (or 'cell') in 2002, but not all cells will be filled with dredged material until at least 2013. As a major objective of the restoration, six species of waterbirds were identified as 'priority species' for Chesapeake Bay: American black duck (Anas rubripes), snowy egret (Egretta thula), cattle egret (Bubulcus ibis), osprey (Pandion haliaetus), common tern (Sterna hirundo), and least tern (S. antillarum). Monitoring of nesting activities of these species from 2002 to 2005 indicated that all species except black ducks colonized the site rapidly. More than 800 pairs of common terns nested in 2003 to 2004. Because of predation by red fox (Vulpes vulpes) and great horned owl (Bubo virginianus), reproductive success was very low for the terns. Trapping was effective in removing the foxes, and other controls have been applied to opportunistic nesting species including herring gulls (Larus argentatus) and Canada geese (Branta canadensis). An effective public education program on the island has helped address concerns about animal control.

Patterns of resource partitioning by nesting herons and ibis: how are odonata exploited?

PubMed

Samraoui, Farrah; Nedjah, Riad; Boucheker, Abdennour; Alfarhan, Ahmed H; Samraoui, Boudjéma

2012-04-01

Herons and ibis are colonially nesting waders which, owing to their number, mobility and trophic role as top predators, play a key role in aquatic ecosystems. They are also good biological models to investigate interspecific competition between sympatric species and predation; two processes which structure ecological communities. Odonata are also numerous, diverse, mobile and can play an important role in aquatic ecosystems by serving as prey for herons and ibis. A relationship between prey size and bird predator has been observed in Numidia wetlands (NE Algeria) after analyzing food boluses regurgitated by six species of birds (Purple Heron, Black-crowned Night Heron, Glossy Ibis, Little Egret, Squacco Heron and Cattle Egret) during the breeding period, which also shows a temporal gradient for the six species. Both the Levins index and preliminary multivariate analysis of the Odonata as prey fed to nestling herons and ibis, indicated a high degree of resource overlap. However, a distinction of prey based on taxonomy (suborder and family) and developmental stage (larvae or adults) reveals a clear size dichotomy with large-sized predators (Purple Heron, Black-crowned Night Heron and Glossy Ibis) preying on large preys like Aeshnids and Libellulids and small-sized predators feeding mainly on small prey like Zygoptera. Overall, the resource utilization suggests a pattern of resource segregation by coexisting nesting herons and ibis based on the timing of reproduction, prey types, prey size and foraging microhabitats. Copyright © 2012 Académie des sciences. Published by Elsevier SAS. All rights reserved.

KENNEDY SPACE CENTER, FLA. -- A tri-colored heron stands sentry in the marshes around KSC. It has slate blue feathers on most of its body except for a white chest and belly and a rust-colored neck. It has long yellow legs, a white stripe that runs up its neck and long pointed yellow bill. The bill turns blue during breeding season.The heron is one of 310 species of birds that inhabit the Merritt Island National Wildlife Refuge, which shares a boundary with KSC. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

NASA Image and Video Library

2004-01-08

KENNEDY SPACE CENTER, FLA. -- A tri-colored heron stands sentry in the marshes around KSC. It has slate blue feathers on most of its body except for a white chest and belly and a rust-colored neck. It has long yellow legs, a white stripe that runs up its neck and long pointed yellow bill. The bill turns blue during breeding season.The heron is one of 310 species of birds that inhabit the Merritt Island National Wildlife Refuge, which shares a boundary with KSC. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

KENNEDY SPACE CENTER, FLA. -- A group of white pelicans spend a few moments relaxing in the water near the Vehicle Assembly Building at Kennedy Space Center. Found from British Columbia south to western Ontario, California and the Texas coast, white pelicans winter from Florida south to Panama. They prefer marshy lakes and coastal regions, and winter chiefly in coastal lagoons. White pelicans are one of 310 species of birds that inhabit the Merritt Island National Wildlife Refuge, which shares a boundary with KSC. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

NASA Image and Video Library

2004-01-08

KENNEDY SPACE CENTER, FLA. -- A group of white pelicans spend a few moments relaxing in the water near the Vehicle Assembly Building at Kennedy Space Center. Found from British Columbia south to western Ontario, California and the Texas coast, white pelicans winter from Florida south to Panama. They prefer marshy lakes and coastal regions, and winter chiefly in coastal lagoons. White pelicans are one of 310 species of birds that inhabit the Merritt Island National Wildlife Refuge, which shares a boundary with KSC. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

Health assessment for San Fernando Valley, San Fernando Valley, Los Angeles County, California, Region 9. CERCLIS Nos. 09CAD980894893, 09CAD980894901, 09CAD980894984, 09CAD980894976. Preliminary report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1989-04-10

A large portion of the ground water in the San Fernando Ground water Basin has been contaminated with volatile organic compounds (VOCs) at concentrations of public health concern. The study area encompasses approximately 190 square miles and currently has 4 designated National Priorities List Sites: North Hollywood, Crystal Springs, Pollock, and Verdugo. The primary contaminants in the study area are PCE and TCE, although other VOCs have been identified in the ground water. The sources of the contamination are currently unidentified and therefore physical hazards such as open storage tanks, vessels, drums, pits, or general debris associated with the sourcesmore » cannot be fully addressed. The sites are considered to be of public health concern because of the risk to human health caused by the likelihood of exposure to hazardous substances through the use of the contaminated groundwater and the potential for exposure at the contaminant source(s) through other exposure pathways.« less

Gamma-rays from the binary system containing PSR J2032+4127 during its periastron passage

NASA Astrophysics Data System (ADS)

Bednarek, Włodek; Banasiński, Piotr; Sitarek, Julian

2018-01-01

The energetic pulsar, PSR J2032+4127, has recently been discovered in the direction of the unidentified HEGRA TeV γ-ray source (TeV J2032+4130). It is proposed that this pulsar forms a binary system with the Be type star, MT91 213, expected to reach periastron late in 2017. We performed detailed calculations of the γ-ray emission produced close to the binary system’s periastron passage by applying a simple geometrical model. Electrons accelerated at the collision region of pulsar and stellar winds initiate anisotropic inverse Compton {e}+/- pair cascades by scattering soft radiation from the massive companion. The γ-ray spectra, from such a comptonization process, are compared with the measurements of the extended TeV γ-ray emission from the HEGRA TeV γ-ray source. We discuss conditions within the binary system, at the periastron passage of the pulsar, for which the γ-ray emission from the binary can overcome the extended, steady TeV γ-ray emission from the HEGRA TeV γ-ray source.

Unrecognized astrometric confusion in the Galactic Centre

NASA Astrophysics Data System (ADS)

Plewa, P. M.; Sari, R.

2018-06-01

The Galactic Centre is a crowded stellar field and frequent unrecognized events of source confusion, which involve undetected faint stars, are expected to introduce astrometric noise on a sub-mas level. This confusion noise is the main non-instrumental effect limiting the astrometric accuracy and precision of current near-infrared imaging observations and the long-term monitoring of individual stellar orbits in the vicinity of the central supermassive black hole. We self-consistently simulate the motions of the known and the yet unidentified stars to characterize this noise component and show that a likely consequence of source confusion is a bias in estimates of the stellar orbital elements, as well as the inferred mass and distance of the black hole, in particular if stars are being observed at small projected separations from it, such as the star S2 during pericentre passage. Furthermore, we investigate modelling the effect of source confusion as an additional noise component that is time-correlated, demonstrating a need for improved noise models to obtain trustworthy estimates of the parameters of interest (and their uncertainties) in future astrometric studies.

The 2HWC HAWC Observatory Gamma-Ray Catalog

NASA Astrophysics Data System (ADS)

Abeysekara, A. U.; Albert, A.; Alfaro, R.; Alvarez, C.; Álvarez, J. D.; Arceo, R.; Arteaga-Velázquez, J. C.; Ayala Solares, H. A.; Barber, A. S.; Baughman, B.; Bautista-Elivar, N.; Becerra Gonzalez, J.; Becerril, A.; Belmont-Moreno, E.; BenZvi, S. Y.; Berley, D.; Bernal, A.; Braun, J.; Brisbois, C.; Caballero-Mora, K. S.; Capistrán, T.; Carramiñana, A.; Casanova, S.; Castillo, M.; Cotti, U.; Cotzomi, J.; Coutiño de León, S.; de la Fuente, E.; De León, C.; Diaz Hernandez, R.; Dingus, B. L.; DuVernois, M. A.; Díaz-Vélez, J. C.; Ellsworth, R. W.; Engel, K.; Fiorino, D. W.; Fraija, N.; García-González, J. A.; Garfias, F.; Gerhardt, M.; González Muñoz, A.; González, M. M.; Goodman, J. A.; Hampel-Arias, Z.; Harding, J. P.; Hernandez, S.; Hernandez-Almada, A.; Hinton, J.; Hui, C. M.; Hüntemeyer, P.; Iriarte, A.; Jardin-Blicq, A.; Joshi, V.; Kaufmann, S.; Kieda, D.; Lara, A.; Lauer, R. J.; Lee, W. H.; Lennarz, D.; León Vargas, H.; Linnemann, J. T.; Longinotti, A. L.; Raya, G. Luis; Luna-García, R.; López-Coto, R.; Malone, K.; Marinelli, S. S.; Martinez, O.; Martinez-Castellanos, I.; Martínez-Castro, J.; Martínez-Huerta, H.; Matthews, J. A.; Miranda-Romagnoli, P.; Moreno, E.; Mostafá, M.; Nellen, L.; Newbold, M.; Nisa, M. U.; Noriega-Papaqui, R.; Pelayo, R.; Pretz, J.; Pérez-Pérez, E. G.; Ren, Z.; Rho, C. D.; Rivière, C.; Rosa-González, D.; Rosenberg, M.; Ruiz-Velasco, E.; Salazar, H.; Salesa Greus, F.; Sandoval, A.; Schneider, M.; Schoorlemmer, H.; Sinnis, G.; Smith, A. J.; Springer, R. W.; Surajbali, P.; Taboada, I.; Tibolla, O.; Tollefson, K.; Torres, I.; Ukwatta, T. N.; Vianello, G.; Villaseñor, L.; Weisgarber, T.; Westerhoff, S.; Wisher, I. G.; Wood, J.; Yapici, T.; Younk, P. W.; Zepeda, A.; Zhou, H.

2017-07-01

We present the first catalog of TeV gamma-ray sources realized with data from the newly completed High Altitude Water Cherenkov Observatory (HAWC). It is the most sensitive wide field-of-view TeV telescope currently in operation, with a one-year survey sensitivity of ˜5%-10% of the flux of the Crab Nebula. With an instantaneous field of view >1.5 sr and >90% duty cycle, it continuously surveys and monitors the sky for gamma-ray energies between hundreds of GeV and tens of TeV. HAWC is located in Mexico, at a latitude of 19° N, and was completed in 2015 March. Here, we present the 2HWC catalog, which is the result of the first source search performed with the complete HAWC detector. Realized with 507 days of data, it represents the most sensitive TeV survey to date for such a large fraction of the sky. A total of 39 sources were detected, with an expected number of false detections of 0.5 due to background fluctuation. Out of these sources, 19 are new sources that are not associated with previously known TeV sources (association criteria: <0.°5 away). The source list, including the position measurement, spectrum measurement, and uncertainties, is reported, then each source is briefly discussed. Of the 2HWC associated sources, 10 are reported in TeVCat as PWN or SNR: 2 as blazars and the remaining eight as unidentified.

The 2HWC HAWC Observatory Gamma-Ray Catalog

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abeysekara, A. U.; Barber, A. S.; Albert, A.

2017-07-01

We present the first catalog of TeV gamma-ray sources realized with data from the newly completed High Altitude Water Cherenkov Observatory (HAWC). It is the most sensitive wide field-of-view TeV telescope currently in operation, with a one-year survey sensitivity of ∼5%–10% of the flux of the Crab Nebula. With an instantaneous field of view >1.5 sr and >90% duty cycle, it continuously surveys and monitors the sky for gamma-ray energies between hundreds of GeV and tens of TeV. HAWC is located in Mexico, at a latitude of 19° N, and was completed in 2015 March. Here, we present the 2HWCmore » catalog, which is the result of the first source search performed with the complete HAWC detector. Realized with 507 days of data, it represents the most sensitive TeV survey to date for such a large fraction of the sky. A total of 39 sources were detected, with an expected number of false detections of 0.5 due to background fluctuation. Out of these sources, 19 are new sources that are not associated with previously known TeV sources (association criteria: <0.°5 away). The source list, including the position measurement, spectrum measurement, and uncertainties, is reported, then each source is briefly discussed. Of the 2HWC associated sources, 10 are reported in TeVCat as PWN or SNR: 2 as blazars and the remaining eight as unidentified.« less

Geomicrobiology of the Ocean Crust: The Phylogenetic Diversity, Abundance, and Distribution of Microbial Communities Inhabiting Basalt and Implications for Rock Alteration Processes

DTIC Science & Technology

2007-06-01

AF317741) 93 EPR3970- MOlA -Bc32 gamma-Proteobacteria Uncultured gamma proteobacterium clone AT-s80 (AY225635) 99 FPR3970-MO IA-Bc33 Actinobacteria...bacterium partial I AJ966584) 99 1iPR3970- MOlA -Bc65 Unidentified Uncultured bacterium clone CV90 (DQ499320) 89 1iPR3970- MOlA -Bc66 Unidentified Uncultured

UNIDENTIFIED CATENARY SUSPENSION BRIDGE ON RIVETED METAL PIERS, SHOWING HOWE ...

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

UNIDENTIFIED CATENARY SUSPENSION BRIDGE ON RIVETED METAL PIERS, SHOWING HOWE PIPE TRUSS RAILING AND TRUSSED DECK BEAMS TYPICAL TO BRIDGES BUILT BY FLINN-MOYER COMPANY. TRIPODAL PIPE TOWERS RESEMBLE CLEAR FORK OF THE BRAZOS SUSPENSION BRIDGE’S TOWERS PRIOR TO ENCASEMENT IN CONCRETE. NOTE COLLAPSED TRUSS IN RIVER. ELEVATION VIEW. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

Dynamical compensation and structural identifiability of biological models: Analysis, implications, and reconciliation.

PubMed

Villaverde, Alejandro F; Banga, Julio R

2017-11-01

The concept of dynamical compensation has been recently introduced to describe the ability of a biological system to keep its output dynamics unchanged in the face of varying parameters. However, the original definition of dynamical compensation amounts to lack of structural identifiability. This is relevant if model parameters need to be estimated, as is often the case in biological modelling. Care should we taken when using an unidentifiable model to extract biological insight: the estimated values of structurally unidentifiable parameters are meaningless, and model predictions about unmeasured state variables can be wrong. Taking this into account, we explore alternative definitions of dynamical compensation that do not necessarily imply structural unidentifiability. Accordingly, we show different ways in which a model can be made identifiable while exhibiting dynamical compensation. Our analyses enable the use of the new concept of dynamical compensation in the context of parameter identification, and reconcile it with the desirable property of structural identifiability.

Estimation of contamination sources of human enteroviruses in a wastewater treatment and reclamation system by PCR-DGGE.

PubMed

Ji, Zheng; Wang, Xiaochang C; Xu, Limei; Zhang, Chongmiao; Funamizu, Naoyuki; Okabe, Satoshi; Sano, Daisuke

2014-06-01

A polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) method was employed to estimate the contamination sources of human enteroviruses and understand how their dominant strains vary in a wastewater treatment and reclamation system consisting of sewage collection, wastewater treatment with membrane bioreactor and open lakes for reclaimed water storage and reuse. After PCR-DGGE using a selected primer set targeting enteroviruses, phylogenetic analysis of acquired enterovirus gene sequences was performed. Enteroviruses identified from the septic tank were much more diverse than those from grey water and kitchen wastewater. Several unique types of enterovirus different from those in wastewater samples were dominant in a biological wastewater treatment unit. Membrane filtration followed by chlorination was proved effective for physically eliminating enteroviruses; however, secondary contamination likely occurred as the reclaimed water was stored in artificial lakes. Enterovirus 71 (EV71), a hand-foot-and-mouth disease (HFMD) viral pathogen, was detected mainly from the artificial lakes, implying that wastewater effluent was not the contamination source of EV71 and that there were unidentified non-point sources of the contamination with the HFMD viral pathogen in the reclaimed water stored in the artificial lakes. The PCR-DGGE targeting enteroviruses provided robust evidence about viral contamination sources in the wastewater treatment and reclamation system.

Comparison of fipronil sources in North Carolina surface water ...

EPA Pesticide Factsheets

Fipronil is a phenylpyrazole insecticide that is widely used in residential and agricultural settings to control ants, roaches, termites, and other pests. Fipronil and its transformation products have been found in a variety of environmental matrices, but the source[s] which makes the greatest contribution to fipronil in surface water has yet to be determined. A sampling effort designed to prioritize known fipronil inputs (golf courses, residential areas, biosolids application sites and wastewater facilities) was conducted in North Carolina to learn more about the origins of fipronil in surface water. High resolution mass spectrometry (HRMS) analysis indicated that fipronil and its known derivatives were routinely present in all samples, but concentrations were substantially elevated near wastewater treatment plant outfalls (range 10–500 ng/L combined), suggesting that they predominate as environmental sources. Corresponding recycled wastewater samples, which were treated with NaOCl for disinfection, showed disappearance of fipronil and all known degradates. HRMS and nuclear magnetic resonance (NMR) analysis techniques were used to determine that all fipronil-related compounds are oxidized to a previously unidentified fipronil sulfone chloramine species in recycled wastewater. The implications of the presence of a new fipronil-related compound in recycled wastewater need to be considered. Journal Article Highlights • The most important sources of fipronil in

Variation with interplanetary sector of the total magnetic field measured at the OGO 2, 4, and 6 satellites

NASA Technical Reports Server (NTRS)

Langel, R. A.

1973-01-01

Variations in the scalar magnetic field (delta B) from the polar orbiting OGO 2, 4, and 6 spacecraft are examined as a function of altitude for times when the interplanetary magnetic field is toward the sun and for times when the interplanetary magnetic field away from the sun. This morphology is basically the same as that found when all data, irrespective of interplanetary magnetic sector, are averaged together. Differences in delta B occur, both between sectors and between seasons, which are similar in nature to variations in the surface delta Z found by Langel (1973c). The altitude variation of delta B at sunlit local times, together with delta Z at the earth's surface, demonstrates that the delta Z and delta B which varies with sector has an ionospheric source. Langel (1973b) showed that the positive delta B region in the dark portion of the hemisphere is due to at least two sources, the westward electrojet and an unidentified non-ionospheric source(s). Comparison of magnetic variations between season/sector at the surface and at the satellite, in the dark portion of the hemisphere, indicates that these variations are caused by variations in the latitudinally narrow electrojet currents and not by variations in the non-ionospheric source of delta B.

Microscopic Sources of Paramagnetic Noise on α-Al2O3 Substrates for Superconducting Qubits

NASA Astrophysics Data System (ADS)

Dubois, Jonathan; Lee, Donghwa; Lordi, Vince

2014-03-01

Superconducting qubits (SQs) represent a promising route to achieving a scalable quantum computer. However, the coupling between electro-dynamic qubits and (as yet largely unidentified) ambient parasitic noise sources has so far limited the functionality of current SQs by limiting coherence times of the quantum states below a practical threshold for measurement and manipulation. Further improvement can be enabled by a detailed understanding of the various noise sources afflicting SQs. In this work, first principles density functional theory (DFT) calculations are employed to identify the microscopic origins of magnetic noise sources in SQs on an α-Al2O3 substrate. The results indicate that it is unlikely that the existence of intrinsic point defects and defect complexes in the substrate are responsible for low frequency noise in these systems. Rather, a comprehensive analysis of extrinsic defects shows that surface aluminum ions interacting with ambient molecules will form a bath of magnetic moments that can couple to the SQ paramagnetically. The microscopic origin of this magnetic noise source is discussed and strategies for ameliorating the effects of these magnetic defects are proposed. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Spatially Resolving the Very High Energy Emission from MGRO J2019+37 with VERITAS

NASA Astrophysics Data System (ADS)

Aliu, E.; Aune, T.; Behera, B.; Beilicke, M.; Benbow, W.; Berger, K.; Bird, R.; Bouvier, A.; Buckley, J. H.; Bugaev, V.; Cerruti, M.; Chen, X.; Ciupik, L.; Connolly, M. P.; Cui, W.; Dumm, J.; Dwarkadas, V. V.; Errando, M.; Falcone, A.; Federici, S.; Feng, Q.; Finley, J. P.; Fleischhack, H.; Fortin, P.; Fortson, L.; Furniss, A.; Galante, N.; Gillanders, G. H.; Gotthelf, E. V.; Griffin, S.; Griffiths, S. T.; Grube, J.; Gyuk, G.; Hanna, D.; Holder, J.; Hughes, G.; Humensky, T. B.; Johnson, C. A.; Kaaret, P.; Kargaltsev, O.; Kertzman, M.; Khassen, Y.; Kieda, D.; Krennrich, F.; Lang, M. J.; Madhavan, A. S.; Maier, G.; McArthur, S.; McCann, A.; Millis, J.; Moriarty, P.; Mukherjee, R.; Nieto, D.; O'Faoláin de Bhróithe, A.; Ong, R. A.; Otte, A. N.; Pandel, D.; Park, N.; Pohl, M.; Popkow, A.; Prokoph, H.; Quinn, J.; Ragan, K.; Rajotte, J.; Reyes, L. C.; Reynolds, P. T.; Richards, G. T.; Roache, E.; Roberts, M.; Sembroski, G. H.; Shahinyan, K.; Smith, A. W.; Staszak, D.; Telezhinsky, I.; Tucci, J. V.; Tyler, J.; Vincent, S.; Wakely, S. P.; Weinstein, A.; Welsing, R.; Wilhelm, A.; Williams, D. A.; Zitzer, B.

2014-06-01

We present very high energy (VHE) imaging of MGRO J2019+37 obtained with the VERITAS observatory. The bright extended (~2°) unidentified Milagro source is located toward the rich star formation region Cygnus-X. MGRO J2019+37 is resolved into two VERITAS sources. The faint, point-like source VER J2016+371 overlaps CTB 87, a filled-center remnant (SNR) with no evidence of a supernova remnant shell at the present time. Its spectrum is well fit in the 0.65-10 TeV energy range by a power-law model with photon index 2.3 ± 0.4. VER J2019+378 is a bright extended (~1°) source that likely accounts for the bulk of the Milagro emission and is notably coincident with PSR J2021+3651 and the star formation region Sh 2-104. Its spectrum in the range 1-30 TeV is well fit with a power-law model of photon index 1.75 ± 0.3, among the hardest values measured in the VHE band, comparable to that observed near Vela-X. We explore the unusual spectrum and morphology in the radio and X-ray bands to constrain possible emission mechanisms for this source.

Surfing for scoliosis: the quality of information available on the Internet.

PubMed

Mathur, Sameer; Shanti, Nael; Brkaric, Mario; Sood, Vivek; Kubeck, Justin; Paulino, Carl; Merola, Andrew A

2005-12-01

A cross section of Web sites accessible to the general public was surveyed. To evaluate the quality and accuracy of information on scoliosis that a patient might access on the Internet. The Internet is a rapidly expanding communications network with an estimated 765 million users worldwide by the year 2005. Medical information is one of the most common sources of inquires on the Web. More than 100 million Americans accessed the Internet for medical information in the year 2000. Undoubtedly, the use of the Internet for patient information needs will continue to expand as Internet access becomes more readily available. This expansion combined with the Internet's poorly regulated format can lead to problems in the quality of information available. Since the Internet operates on a global scale, implementing and enforcing standards have been difficult. The largely uncontrolled information can potentially negatively influence consumer health outcomes. To identify potential sites, five search engines were selected and the word "scoliosis" was entered into each search engine. A total of 50 Web sites were chosen for review. Each Web site was evaluated according to the type of Web site, quality content, and informational accuracy by three board-certified academic orthopedic surgeons, fellowship trained in spinal surgery, who each has been in practice for a minimum of 8 years. Each Web site was categorized as academic, commercial, physician, nonphysician health professional, and unidentified. In addition, each Web site was evaluated according to scoliosis-specific content using a point value system of 32 disease-specific key words pertinent to the care of scoliosis on an ordinal scale. A list of these words is given. Point values were given for the use of key words related to disease summary, classifications, treatment options, and complications. The accuracy of the individual Web site was evaluated by each spine surgeon using a scale of 1 to 4. A score of 1 represents that the examiner agreed with less than 25% of the information while a score of 4 represents greater than 75% agreement. Of the total 50 Web sites evaluated, 44% were academic, 18% were physician based, 16% were commercial, 12% were unidentified, and 10% were nonphysician health professionals. The quality content score (maximum, 32 points) for academic sites was 12.6 +/- 3.8, physician sites 11.3 +/- 4.0, commercial sites 11 +/- 4.2, unidentified 7.6 +/- 3.9, and nonphysician health professional site 7.0 +/- 1.8. The accuracy score (maximum, 12 points) was 6.6 +/- 2.4 for academic sites, 6.3 +/- 3.0 for physician-professional sites, 6.0 +/- 2.7 for unidentified sites, 5.5 +/- 3.8 for nonphysician professional sites, and 5.0 +/- 1.5 for commercial Web sites. The academic Web sites had the highest mean scores in both quality and accuracy content scores. The information about scoliosis on the Internet is of limited quality and poor information value. Although the majority of the Web sites were academic, the content quality and accuracy scores were still poor. The lowest scoring Web sites were the nonphysician professionals and the unidentified sites, which were often message boards. Overall, the highest scoring Web site related to both quality and accuracy of information was www.srs.org. This Web site was designed by the Scoliosis Research Society. The public and the medical communities need to be aware of these existing limitations of the Internet. Based on our review, the physician must assume primary responsibility of educating and counseling their patients.

2-45 Micron Infrared Spectroscopy of Carbon-Rich Proto-Planetary Nebulae

NASA Technical Reports Server (NTRS)

Hrivnak, Bruce J.; Volk, Kevin; Kwok, Sun

2000-01-01

Infrared Space Observatory (ISO) 2-45 micron observations of seven proto-planetary nebulae (PPNs) and two other carbon-rich objects are presented. The unidentified emission features at 21 and 30 microns are detected in six sources, including four new detections of the 30 micron feature. This previously unresolved 30 micron feature is now resolved and found to consist of a broad feature peaking at 27.2 microns (the '30 micron' feature) and a narrower feature at 25.5 microns (the '26 micron' feature). This new 26 micron feature is detected in eight sources and is particularly strong in IRAS Z02229 + 6208 and 16594-4656. The unidentified infrared (UIR) emission features at 3.3, 6.2, 7.7, and 11.3 microns which are commonly observed in planetary nebulae and H II regions, are also seen in these PPNs. However, their strengths relative to the continuum plateaus at 8 and 12 microns are weaker than in planetary nebulae. The 6.9 micron feature, seen almost exclusively in PPNs, is strong. New millimeter CO and HCN observations were made; they support the carbon-rich nature of the objects and yield the expansion velocities of the gaseous envelopes. The spectral energy distributions of these PPNs were fitted with a radiative-transfer model, taking into account the emission features at 21, 26, and 30 microns. A significant fraction of the total energy output is emitted in these features: as high as 20% in the 30 micron feature and 8% in the 21 micron feature. The fact that so much energy is carried in these features suggests that the material responsible for these features must be made of abundant elements and most likely involves carbon. SiS, appears to be ruled out as the emitter of the 21 micron feature due to the absence of a predicted companion feature.

KSC-08pd3162

NASA Image and Video Library

2008-10-14

CAPE CANAVERAL, Fla. - A great blue heron stands watch among a pond of water lilies on NASA's Kennedy Space Center in Florida. It is one of 310 species of birds that inhabit the National Merritt Island Wildlife Refuge, which shares a boundary with Kennedy. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds. Photo credit: NASA/Dimitri Gerondidakis

Wildlife Photography - Birds

NASA Image and Video Library

2017-12-14

A little green heron is perched in a tree at NASA's Kennedy Space Center in Florida. Kennedy shares a boundary with the Merritt Island National Wildlife Refuge. The refuge encompasses 140,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fish, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

KSC-2011-8382

NASA Image and Video Library

2011-12-21

CAPE CANAVERAL, Fla. – Perched on a section of pipe, this snowy egret keeps a wary eye on the photographer on a sunny day at Black Point Wildlife Drive, part of the Merritt Island National Wildlife Refuge. NASA's Kennedy Space Center shares a boundary with the refuge, consisting of 140,000 acres. The Refuge provides a wide variety of habitats: coastal dunes, saltwater estuaries and marshes, freshwater impoundments, scrub, pine flatwoods, and hardwood hammocks that provide habitat for more than 1,500 species of plants and animals, including about 331 species of birds. Photo credit: NASA/Jim Grossmann

KSC-04PD-1246

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. A pair of stilts meet near their nest in a marsh near KSC, which shares a boundary with the Merritt Island National Wildlife Refuge. Stilts inhabit salt marshes and shallow coastal bays in the East. Their nests are shallow depressions lined with grass or shell fragments. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

KSC-05PD-1019

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. A black-necked stilt, foraging for food, pays no attention to a great egret as it comes in for a landing in a marshy area of the Merritt Island National Wildlife Refuge. The refuge was established in 1963 on Kennedy Space Center land and water not used by NASA for the space program. The marshes and open water of the refuge provide wintering grounds for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

Patterns of gastro-intestinal parasites and commensals as an index of population and ecosystem health: the case of sympatric western chimpanzees (Pan troglodytes verus) and guinea baboons (Papio hamadryas papio) at Fongoli, Senegal.

PubMed

Howells, Michaela E; Pruetz, Jill; Gillespie, Thomas R

2011-02-01

The exponential decline of great apes over the past 50 years has resulted in an urgent need for data to inform population viability assessment and conservation strategies. Health monitoring of remaining ape populations is an important component of this process. In support of this effort, we examined endoparasitic and commensal prevalence and richness as proxies of population health for western chimpanzees (Pan troglodytes verus) and sympatric guinea baboons (Papio hamadryas papio) at Fongoli, Senegal, a site dominated by woodland-savanna at the northwestern extent of chimpanzees' geographic range. The small population size and extreme environmental pressures experienced by Fongoli chimpanzees make them particularly sensitive to the potential impact of pathogens. One hundred thirty-two chimpanzee and seventeen baboon fecal samples were processed using sodium nitrate floatation and fecal sedimentation to isolate helminth eggs, larvae, and protozoal cysts. Six nematodes (Physaloptera sp., Ascaris sp., Stronglyloides fuelleborni, Trichuris sp., an unidentified hookworm, and an unidentified larvated nematode), one cestode (Bertiella sp.), and five protozoans (Iodamoeba buetschlii, Entamoeba coli, Troglodytella abrassarti, Troglocorys cava, and an unidentified ciliate) were detected in chimpanzee fecal samples. Four nematodes (Necator sp., S. fuelleborni, Trichuris sp., and an unidentified hookworm sp.), two trematodes (Shistosoma mansoni and an unidentified fluke), and six protozoans (Entamoeba histolytica/dispar, E. coli, Chilomastix mesnili, Balantidium coli, T. abrassarti, and T. cava) were detected in baboon fecal samples. The low prevalence of pathogenic parasite species and high prevalence of symbiotic protozoa in Fongoli chimpanzees are indicative of good overall population health. However, the high prevalence of pathogenic parasites in baboons, who may serve as transport hosts, highlight the need for ongoing pathogen surveillance of the Fongoli chimpanzee population and point to the need for further research into the epidemiology and cross-species transmission ecology of zoonotic pathogens at this site. © 2010 Wiley-Liss, Inc.

Paracoccus panacisoli sp. nov., isolated from a forest soil cultivated with Vietnamese ginseng.

PubMed

Nguyen, Ngoc-Lan; Kim, Yeon-Ju; Hoang, Van-An; Tran, Bao-Tram; Pham, Huong-Son; Yang, Deok-Chun

2015-05-01

A novel bacterial strain, designated DCY94(T), was isolated from forest soil cultivated with ginseng in Vietnam. The strain was Gram-reaction-negative, facultatively anaerobic, non-motile, rod-shaped and catalase- and oxidase-positive. 16S rRNA gene sequence analysis demonstrated that strain DCY94(T) was closely related to Paracoccus sphaerophysae Zy-3(T) (97.5% 16S rRNA gene sequence similarity) and Paracoccus caeni MJ17(T) (96.9%). The fatty acid profile of strain DCY94(T) contained a predominant amount of summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c; 88.4%) and moderate to small quantities of C8 : 0 3-OH (1.0%), C10 : 0 3-OH (2.8%) and C18 : 0 (5.2%). Phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and one unidentified glycolipid were major polar lipids; one unidentified aminolipid, one unidentified aminophospholipid, one unidentified phospholipid and four unidentified polar lipids were minor components. The polyamine pattern comprised the major compounds putrescine and spermidine and minor amounts of sym-homospermidine and spermine. The ubiquinone of the strain was Q-10 and the G+C content of its genomic DNA was 68.3 mol%. All these results support the placement of strain DCY94(T) within the genus Paracoccus . Levels of DNA-DNA relatedness between strain DCY94(T) and P. sphaerophysae HAMBI 3106(T) and P. caeni KCTC 22480(T) were 52 and 50%, respectively. The results of phylogenetic analysis, phenotypic tests, chemotaxonomic characterization and DNA-DNA relatedness studies distinguished strain DCY94(T) from the closest recognized species of the genus Paracoccus , suggesting that this strain represents a novel species, for which the name Paracoccus panacisoli sp. nov. is proposed. The type strain is DCY94(T) ( = KCTC 42086(T) =JCM 30337(T)). © 2015 IUMS.

Paenibacillus lupini sp. nov., isolated from nodules of Lupinus albus.

PubMed

Carro, Lorena; Flores-Félix, José David; Ramírez-Bahena, Martha-Helena; García-Fraile, Paula; Martínez-Hidalgo, Pilar; Igual, José M; Tejedor, Carmen; Peix, Alvaro; Velázquez, Encarna

2014-09-01

A bacterial strain designated RLAHU15(T) was isolated from root nodules of Lupinus albus in Spain. Phylogenetic analyses based on 16S rRNA gene sequences placed the isolate in the genus Paenibacillus, with its closest relatives being Paenibacillus catalpae D75(T), Paenibacillus glycanilyticus DS-1(T), Paenibacillus endophyticus PECAE04(T) and Paenibacillus xinjiangensis B538(T) with 98.8 %, 98.9 %, 97.4 % and 97.4 % similarity, respectively. DNA-DNA hybridization studies showed values lower than 45 % between the strain RLAHU15(T) and any of these species. The isolate was a Gram-stain positive, motile and sporulating rod. Catalase activity was weak and oxidase activity was positive. Casein and starch were hydrolysed but gelatin was not. Growth was supported by many carbohydrates and organic acids as carbon sources. MK-7 was the only menaquinone detected and anteiso-C15 : 0 and iso-C16 : 0 were the major fatty acids. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, three unidentified phospholipids and an unidentified lipid. meso-Diaminopimelic acid was detected in the peptidoglycan. The DNA G+C content was 54.4 mol%. Phylogenetic, chemotaxonomic and phenotypic analyses showed that strain RLAHU15(T) represents a novel species of the genus Paenibacillus, for which the name Paenibacillus lupini sp. nov. is proposed. The type strain is RLAHU15(T) ( = LMG 27296(T) = CECT 8235(T)). © 2014 IUMS.

Somatic Symptom Disorder in Semantic Dementia: The Role of Alexisomia.

PubMed

Gan, Joanna J; Lin, Andrew; Samimi, Mersal S; Mendez, Mario F

Semantic dementia (SD) is a neurodegenerative disorder characterized by loss of semantic knowledge. SD may be associated with somatic symptom disorder due to excessive preoccupation with unidentified somatic sensations. To evaluate the frequency of somatic symptom disorder among patients with SD in comparison to comparably demented patients with Alzheimer׳s disease. A retrospective cohort study was conducted using clinical data from a referral-based behavioral neurology program. Fifty-three patients with SD meeting criteria for imaging-supported semantic variant primary progressive aphasia (another term for SD) were compared with 125 patients with clinically probable Alzheimer disease. Logistic regression controlled for sex, age, disease duration, education, overall cognitive impairment, and depression. The prevalence of somatic symptom disorder was significantly higher among patients with SD (41.5%) compared to patients with Alzheimer disease (11.2%) (odds ratio = 6:1; p < 0.001). Somatic symptom disorder was associated with misidentification and preoccupation with normal bodily sensations such as hunger, bladder filling, borborygmi, rhinorrhea, and reflux; excessive concern over the incompletely understood meaning or source of pain or other symptoms; and Cotard syndrome or the delusion that unidentified somatic symptoms signify death or deterioration. SD, a disorder of semantic knowledge, is associated with somatic symptom disorder from impaired identification of somatic sensations. Their inability to read and name somatic sensations, or "alexisomia," results in disproportionate and persistent concern about somatic sensations with consequent significant disability. Copyright © 2016 The Academy of Psychosomatic Medicine. Published by Elsevier Inc. All rights reserved.

Novel methyl transfer during chemotaxis in Bacillus subtilis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thoelke, M.S.; Kirby, J.R.; Ordal, G.W.

1989-06-27

If Bacillus subtilis is incubated in radioactive methionine in the absence of protein synthesis, the methyl-accepting chemotaxis proteins (MCPs) become radioactively methylated. If the bacteria are further incubated in excess nonradioactive methionine (cold-chased) and then given the attractant aspartate, the MCPs lose about half of their radioactivity due to turnover, in which lower specific activity methyl groups from S-adenosylmethionine (AdoMet) replace higher specific activity ones. Due to the cold-chase, the specific activity of the AdoMet pool is reduced at least 2-fold. If, later, the attractant is removed, higher specific activity methyl groups return to the MCPs. Thus, there must existmore » an unidentified methyl carrier than can reversibly receive methyl groups from the MCPs. In a similar experiment, labeled cells were transferred to a flow cell and exposed to addition and removal of attractant and of repellent. All four kinds of stimuli were found to cause methanol production. Bacterial with maximally labeled MCPs were exposed to many cycles of addition and removal of attractant; the maximum amount of radioactive methanol was evolved on the third, not the first, cycle. This result suggests that there is a precursor-product relationship between methyl groups on the MCPs and on the unidentified carrier, which might be the direct source of methanol. However, since no methanol was produced when a methyltransferase mutant, whose MCPs were unmethylated, was exposed to addition and removal of attractant or repellent, the methanol must ultimately derive from methylated MCPs.« less

Early Cretaceous stratigraphy, paleontology, and sedimentary tectonics in Paris overthrust foredeep (western Wyoming and southeastern Idaho) compared with Quaternary features of indo-gangetic plain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dorr, J.A. Jr.

1983-08-01

Fluviatile clastics of the nonmarine, early Cretaceous Gannett and Wayan groups were deposited on wet alluvial megafans and on intervening interfan piedmont slopes which declined eastward into more poorly drained lowlands from a western highland source area uplifted episodically by movements of the Paris overthrust. Lacustrine episodes of deposition intercalated Peterson and Draney limestones with Gannett fluvial clastics. Westward marine transgressions (Skull Creek, Mowry) intercalated mixed lacustrine and brackish facies (Smiths and Cokedale formations) into Wayan fluviatile clastics. Newly discovered fossil vertebrate and invertebrate materials (all fragmentary but identifiable) include: Gannett Group - large reptiles including turtles; Thomas Fork Formationmore » - freshwater gastropods and unionid pelecypods, gastroliths, two types of turtles, large reptilian fragments (dinosaur), and abundant dinosaur eggshell fragments; Wayan Formation - perennially aquatic snails, turtles, unidentifiable large reptiles, two types of crocodilians, an iguanodontid dinosaur (Tenontosaurus), an ankylosaurian dinosaur, a large ornithopod dinosaur, gastroliths, abundant and ubiquitous dinosaur eggshell fragments (numerous types and sizes), and miscellaneous unidentifiable small vertebrate bone fragments. A census of analogous modern reptile reproductive behaviors supports the conclusion that the Wayan, and probably also the Gannett, alluvial fan environments were used as upland breeding grounds by dinosaurs and perhaps other reptiles. Comparison of these Early Cretaceous data with observations on the tectonic setting, sedimentology, and biology of the Quaternary indo-gangetic plain suggests many close analogies between the two sedimentary tectonic settings.« less

Comparison of hybrid receptor models to locate PCB sources in Chicago

NASA Astrophysics Data System (ADS)

Hsu, Ying-Kuang; Holsen, Thomas M.; Hopke, Philip K.

Results of three hybrid receptor models, potential source contribution function (PSCF), concentration weighted trajectory (CWT), and residence time weighted concentration (RTWC), were compared for locating polychlorinated biphenyl (PCB) sources contributing to the atmospheric concentrations in Chicago. Variations of these models, including PSCF using mean and 75% criterion concentrations, joint probability PSCF (JP-PSCF), changes of point filters and grid cell sizes for RTWC, and PSCF using wind trajectories started at different altitudes, are also discussed. Modeling results were relatively consistent between models. However, no single model provided as complete information as was obtained by using all of them. CWT and 75% PSCF appears to be able to distinguish between larger sources and moderate ones. RTWC resolved high potential source areas. RTWC and JP-PSCF pooling data from all sampling sites removed the trailing effect often seen in PSCF modeling. PSCF results using average concentration criteria, appears to identify both moderate and major sources. Each model has advantages and disadvantages. However, used in combination, they provide information that is not available if only one of them is used. For short-range atmospheric transport, PSCF results were consistent when using wind trajectories starting at different heights. Based on the archived PCB data, the modeling results indicate there is a large potential source area between Joliet and Kankakee, IL, and two moderate sources to the northwest and south of Chicago. On the south side of Chicago in the neighborhood of Lake Calumet, several PCB sources were identified. Other unidentified potential source location(s) will require additional upwind/downwind field sampling to verify modeling results.

[Spectral diversity among the members of the family of Green Fluorescent Protein in hydroid jellyfish (Cnidaria, Hydrozoa)].

PubMed

Ianushevich, Iu G; Shagin, D A; Fradkov, A F; Shakhbazov, K S; Barsova, E V; Gurskaia, N G; Labas, Iu A; Matts, M V; Luk'ianov, k A; Lul'ianov, S A

2005-01-01

The cDNAs encoding the genes of new proteins homologous to the well-known Green Fluorescent Protein (GFP) from the hydroid jellyfish Aequorea victoria were cloned. Two green fluorescent proteins from one un-identified anthojellyfish, a yellow fluorescent protein from Phialidium sp., and a nonfluorescent chromoprotein from another unidentified anthojellyfish were characterized. Thus, a broad diversity of GFP-like proteins among the organisms of the class Hydrozoa in both spectral properties and primary structure was shown.

[The coordination of the forensic medical service with the medical criminology subdivisions of internal affairs organs in the personal identification of unidentified corpses].

PubMed

Pashinian, G A; Tuchik, E S

1997-01-01

In order to improve the cooperation between medical criminology departments of the organs of home affairs and forensic medical service in personality identification of unidentified corpses, the authors propose amendments to the routine procedure regulated by documents of the Ministry of Home Affairs of the Russian Federation, for these documents are in need of serious correction and revision, so that they conform to the judicial legislation and other documents.

Isolation of an unidentified pink-pigmented bacterium in a clinical specimen.

PubMed Central

Odugbemi, T; Nwofor, C; Joiner, K T

1988-01-01

An unidentified pink-pigmented bacterium isolated from a clinical specimen is reported. The organism was oxidase, urease, and catalase positive; it grew on Thayer-Martin and MacConkey media. The isolate is possibly similar to an unnamed taxon (G.L. Gilardi and Y.C. Faur, J. Clin. Microbiol. 20:626-629, 1984); however, it had unique characteristics of nonmotility with no flagellum detectable and was a gram-negative coccoid with a few rods in pairs and negative for starch hydrolysis. PMID:3384903

Isolation of an unidentified pink-pigmented bacterium in a clinical specimen.

PubMed

Odugbemi, T; Nwofor, C; Joiner, K T

1988-05-01

An unidentified pink-pigmented bacterium isolated from a clinical specimen is reported. The organism was oxidase, urease, and catalase positive; it grew on Thayer-Martin and MacConkey media. The isolate is possibly similar to an unnamed taxon (G.L. Gilardi and Y.C. Faur, J. Clin. Microbiol. 20:626-629, 1984); however, it had unique characteristics of nonmotility with no flagellum detectable and was a gram-negative coccoid with a few rods in pairs and negative for starch hydrolysis.

Integrated magnetic, gravity, and GPR surveys to locate the probable source of hydrocarbon contamination in Sharm El-Sheikh area, south Sinai, Egypt

NASA Astrophysics Data System (ADS)

Morsy, Mona; Rashed, Mohamed

2013-01-01

Sharm El-Sheikh waters were suddenly hit by hydrocarbon spills which created a serious threat to the prosperous tourism industry in and around the city. Analysis of soil samples, water samples, and seabed samples collected in and around the contaminated bay area showed anomalous levels of hydrocarbons. An integrated geophysical investigation, using magnetic, gravity, and ground penetrating radar geophysical tools, was conducted in the headland overlooking the contaminated bay in order to delineate the possible subsurface source of contamination. The results of the geophysical investigations revealed three underground manmade reinforced concrete tanks and a complicated network of buried steel pipes in addition to other unidentified buried objects. The depths and dimensions of the discovered objects were determined. Geophysical investigations also revealed the presence of a north-south oblique slip fault running through the eastern part of the studied area. Excavations, conducted later on, confirmed the presence of one of the tanks delineated by the geophysical surveys.

Two enzymes with redundant fructose bisphosphatase activity sustain gluconeogenesis and virulence in Mycobacterium tuberculosis.

PubMed

Ganapathy, Uday; Marrero, Joeli; Calhoun, Susannah; Eoh, Hyungjin; de Carvalho, Luiz Pedro Sorio; Rhee, Kyu; Ehrt, Sabine

2015-08-10

The human pathogen Mycobacterium tuberculosis (Mtb) likely utilizes host fatty acids as a carbon source during infection. Gluconeogenesis is essential for the conversion of fatty acids into biomass. A rate-limiting step in gluconeogenesis is the conversion of fructose 1,6-bisphosphate to fructose 6-phosphate by a fructose bisphosphatase (FBPase). The Mtb genome contains only one annotated FBPase gene, glpX. Here we show that, unexpectedly, an Mtb mutant lacking GLPX grows on gluconeogenic carbon sources and has detectable FBPase activity. We demonstrate that the Mtb genome encodes an alternative FBPase (GPM2, Rv3214) that can maintain gluconeogenesis in the absence of GLPX. Consequently, deletion of both GLPX and GPM2 is required for disruption of gluconeogenesis and attenuation of Mtb in a mouse model of infection. Our work affirms a role for gluconeogenesis in Mtb virulence and reveals previously unidentified metabolic redundancy at the FBPase-catalysed reaction step of the pathway.