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Articles 1021 - 1050 of 1383

Full-Text Articles in Physical Sciences and Mathematics

Grb 080913 At Redshift 6.7, J. Greiner, T. Krühler, J. P. U. Fynbo, A. Rossi, R. Schwarz, S. Klose, S. Savaglio, N. R. Tanvir, S. Mcbreen, T Totani, B B. Zhang, X F. Wu, D Watson, S D. Barthelmy, A P. Beardmore, P Ferrero, N Gehrels, D A. Kann, N Kawai, A Küpcü Yoldaş, P Mészáros, B Milvang-Jensen, S R. Oates, D Pierini, P Schady, K Toma, P M. Vreeswijk, A Yoldas, B Zhang, P Afonso, K Aoki, D N. Burrows, C Clemens, R Filgas, Z Haiman, Dieter H. Hartmann Mar 2009

Grb 080913 At Redshift 6.7, J. Greiner, T. Krühler, J. P. U. Fynbo, A. Rossi, R. Schwarz, S. Klose, S. Savaglio, N. R. Tanvir, S. Mcbreen, T Totani, B B. Zhang, X F. Wu, D Watson, S D. Barthelmy, A P. Beardmore, P Ferrero, N Gehrels, D A. Kann, N Kawai, A Küpcü Yoldaş, P Mészáros, B Milvang-Jensen, S R. Oates, D Pierini, P Schady, K Toma, P M. Vreeswijk, A Yoldas, B Zhang, P Afonso, K Aoki, D N. Burrows, C Clemens, R Filgas, Z Haiman, Dieter H. Hartmann

Publications

We report on the detection by Swift of GRB 080913, and subsequent optical/near-infrared follow-up observations by GROND, which led to the discovery of its optical/NIR afterglow and the recognition of its high-z nature via the detection of a spectral break between the i and z bands. Spectroscopy obtained at the ESO-VLT revealed a continuum extending down to λ = 9400 Å, and zero flux for 7500 Å<λ< 9400 Å, which we interpret as the onset of a Gunn–Peterson trough at z = 6.695± 0.025 (95.5% confidence level), making GRB 080913 the highest-redshift gamma-ray burst (GRB) to date, and more distant than the highest-redshift QSO. We note that many redshift indicators that are based on promptly available burst or afterglow properties have failed for GRB 080913. We report on our follow-up campaign and compare the properties of GRB 080913 with bursts at lower redshift. In particular, since the afterglow of this burst is fainter than typical for GRBs, we show that 2 m class telescopes can identify most high-redshift GRBs.

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The Noctilucent Cloud (Nlc) Display During The Ecoma/Mass Sounding Rocket Flights On 3 August 2007: Morphology On Global To Local Scales, G. Baumgarten, J. Fiedler, K. H. Fricke, M. Gerding, M. Hervig, P. Hoffmann, N. Müller, Pierre-Dominique Pautet, M. Rapp, C. Robert, D. Rusch, C. Von Savigny, W. Singer Mar 2009

The Noctilucent Cloud (Nlc) Display During The Ecoma/Mass Sounding Rocket Flights On 3 August 2007: Morphology On Global To Local Scales, G. Baumgarten, J. Fiedler, K. H. Fricke, M. Gerding, M. Hervig, P. Hoffmann, N. Müller, Pierre-Dominique Pautet, M. Rapp, C. Robert, D. Rusch, C. Von Savigny, W. Singer

Publications

During the ECOMA/MASS rocket campaign large scale NLC/PMC was observed by satellite, lidar and camera from polar to mid latitudes. We examine the observations from different instruments to investigate the morphology of the cloud. Satellite observations show a planetary wave 2 structure. Lidar observations from Kühlungsborn (54° N), Esrange (68° N) and ALOMAR (69° N) show a highly dynamic NLC layer. Under favorable solar illumination the cloud is also observable by ground-based cameras. The cloud was detected by cameras from Trondheim (63° N), Juliusruh (55° N) and Kühlungsborn. We investigate planetary scale morphology and local scale gravity wave structures, important …

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Modeling Effects Of Human Single Nucleotide Polymorphisms On Protein-Protein Interactions, Shaolei Teng, Thomas Madej, Anna Panchenko, Emil Alexov Mar 2009

Modeling Effects Of Human Single Nucleotide Polymorphisms On Protein-Protein Interactions, Shaolei Teng, Thomas Madej, Anna Panchenko, Emil Alexov

Publications

A large set of three-dimensional structures of 264 protein-protein complexes with known nonsynonymous single nucleotide polymorphisms (nsSNPs) at the interface was built using homology-based methods. The nsSNPs were mapped on the proteins' structures and their effect on the binding energy was investigated with CHARMM force field and continuum electrostatic calculations. Two sets of nsSNPs were studied: disease annotated Online Mendelian Inheritance in Man (OMIM) and nonannotated (non-OMIM). It was demonstrated that OMIM nsSNPs tend to destabilize the electrostatic component of the binding energy, in contrast with the effect of non-OMIM nsSNPs. In addition, it was shown that the change of …

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Dynamical And Precipitation Structures Of Poleward-Moving Tropical Cyclones In Eastern Canada, 1979-2005, Shawn M. Milrad, Eyad H. Atallah, John R. Gyakum Mar 2009

Dynamical And Precipitation Structures Of Poleward-Moving Tropical Cyclones In Eastern Canada, 1979-2005, Shawn M. Milrad, Eyad H. Atallah, John R. Gyakum

Publications

Tropical cyclones in the western North Atlantic basin are a persistent threat to human interests along the east coast of North America. Occurring mainly during the late summer and early autumn, these storms often cause strong winds and extreme rainfall and can have a large impact on the weather of eastern Canada. From 1979 to 2005, 40 named (by the National Hurricane Center) tropical cyclones tracked over eastern Canada. Based on the time tendency of the low-level (850–700 hPa) vorticity, the storms are partitioned into two groups: ‘‘intensifying’’ and ‘‘decaying.’’ The 16 intensifying and 12 decaying cases are then analyzed …

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Book Review: Electronic Imaging In Astronomy: Detectors And Instrumentation 2nd Ed., T. D. Oswalt Mar 2009

Book Review: Electronic Imaging In Astronomy: Detectors And Instrumentation 2nd Ed., T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of Electronic imaging in astronomy : detectors and instrumentation 2nd ed. by Ian S. McLean, Springer/Praxis, 2008 552p, 9783540765820 $99.00

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The Dust Cloud Around The White Dwarf G 29-38. Ii. Spectrum From 5 To 40 Μm And Mid-Infrared Photometric Variability, William T. Reach, Ted Von Hippel, Et Al. Mar 2009

The Dust Cloud Around The White Dwarf G 29-38. Ii. Spectrum From 5 To 40 Μm And Mid-Infrared Photometric Variability, William T. Reach, Ted Von Hippel, Et Al.

Publications

We model the mineralogy and distribution of dust around the white dwarf G29-39 using the infrared spectrum from 1 to 35 μm. The spectral model for G29-38 dust combines a wide range of materials based on spectral studies of comets and debris disks. In order of their contribution to the mid-infrared emission, the most abundant minerals around G29-38 are amorphous carbon (λ < 8 μm), amorphous and crystalline silicates (5-40 μm), water ice (10-15 and 23-35 μm), and metal sulfides (18-28 μm). The amorphous C can be equivalently replaced by other materials (like metallic Fe) with featureless infrared spectra. The best-fitting crystalline silicate is Fe-rich pyroxene. In order to absorb enough starlight to power the observed emission, the disk must either be much thinner than the stellar radius (so that it can be heated from above and below) or it must have an opening angle wider than 2°. A "moderately optically thick" torus model fits well if the dust extends inward to 50 times the white dwarf radius, all grains hotter than 1100 K are vaporized, the optical depth from the star through the disk is τ∥ = 5, and the radial density profile ∝r –2.7; the total mass of this model disk is 2 × 1019 g. A physically thin (less than the white dwarf radius) and optically thick disk can contribute to the near-infrared continuum only; such a disk cannot …

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In Situ Probes Of The First Galaxies And Reionization: Gamma-Ray Bursts, Matthew Mcquinn, Joshua S. Bloom, Jonathan Grindlay, David Band, S. D. Barthemy, E. Berger, A. Corsi, S. Covino, G. J. Fishman, Steven R. Furlanetto, Neil Gehrels, Dieter H. Hartmann, Chryssa Kouveliotou, A S. Kutyrev, Abraham Loeb, S Harvard Moseley, Tsvi Piran, L Piro, J X. Prochaska, R Salvaterra, P Schady, A M. Soderberg, G Tagliaferri Feb 2009

In Situ Probes Of The First Galaxies And Reionization: Gamma-Ray Bursts, Matthew Mcquinn, Joshua S. Bloom, Jonathan Grindlay, David Band, S. D. Barthemy, E. Berger, A. Corsi, S. Covino, G. J. Fishman, Steven R. Furlanetto, Neil Gehrels, Dieter H. Hartmann, Chryssa Kouveliotou, A S. Kutyrev, Abraham Loeb, S Harvard Moseley, Tsvi Piran, L Piro, J X. Prochaska, R Salvaterra, P Schady, A M. Soderberg, G Tagliaferri

Publications

The first structures in the Universe formed at z > 7, at higher redshift than all currently known galaxies. Since GRBs are brighter than other cosmological sources at high redshift and exhibit simple power-law afterglow spectra that is ideal for absorption studies, they serve as powerful tools for studying the early universe. New facilities planned for the coming decade will be able to obtain a large sample of high-redshift GRBs. Such a sample would constrain the nature of the first stars, galaxies, and the reionization history of the Universe.

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Simulation Scoring Systems, Raynald Bedard Feb 2009

Simulation Scoring Systems, Raynald Bedard

Publications

Simulation scoring systems including software, methods of use, and related methods that provide for simulating and scoring of aircraft flight and other missions, particularly where such simulating is purely electronic and particularly where such scoring is objective and particularly where such scoring has a plurality of gradations, as to distinguish a plurality of skill levels.

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Ratiometric Single-Nanoparticle Oxygen Sensors For Biological Imaging, Changfeng Wu, Barbara Bull, Kenneth Christensen, Jason Mcneill Feb 2009

Ratiometric Single-Nanoparticle Oxygen Sensors For Biological Imaging, Changfeng Wu, Barbara Bull, Kenneth Christensen, Jason Mcneill

Publications

It makes sense: Conjugated polymer nanoparticles doped with a platinum porphyrin dye exhibit bright phosphorescence that is highly sensitive to the concentration of molecular oxygen. The small size, extraordinary brightness, excellent sensitivity, and ratiometric emission, together with the demonstration of single-particle sensing and cellular uptake, indicate the potential of the nanoparticle sensors for quantitative mapping of local molecular oxygen concentration.

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Hd 100453: A Link Between Gas-Rich Protoplanetary Disks And Gas-Poor Debris Disks, K A. Collins, C A. Grady, K Hamaguchi, J P. Wisniewski, Sean D. Brittain, M Sitko, W J. Carpenter, J P. Williams, G S. Mathews, G M. Williger, R Van Boekel, A Carmona, Th. Henning, M E. Van Den Ancker, G Meeus, X P. Chen, R Petre, B E. Woodgate Feb 2009

Hd 100453: A Link Between Gas-Rich Protoplanetary Disks And Gas-Poor Debris Disks, K A. Collins, C A. Grady, K Hamaguchi, J P. Wisniewski, Sean D. Brittain, M Sitko, W J. Carpenter, J P. Williams, G S. Mathews, G M. Williger, R Van Boekel, A Carmona, Th. Henning, M E. Van Den Ancker, G Meeus, X P. Chen, R Petre, B E. Woodgate

Publications

HD 100453 has an IR spectral energy distribution (SED) which can be fit with a power law plus a blackbody. Previous analysis of the SED suggests that the system is a young Herbig Ae star with a gas-rich, flared disk. We reexamine the evolutionary state of the HD 100453 system by refining its age (based on a candidate low-mass companion) and by examining limits on the disk extent, mass accretion rate, and gas content of the disk environment. We confirm that HD 100453B is a common proper motion companion to HD 100453A, with a spectral type of M4.0V-M4.5V, and derive …

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Convection: The Likely Source Of The Medium-Scale Gravity Waves Observed In The Oh Airglow Layer Near Brasilia, Brazil, During The Spreadfex Campaign, Sharon L. Vadas, Michael J. Taylor, Pierre-Dominique Pautet, P. A. Stamus, David C. Fritts, H. L. Liu, F. T. São Sabbos, V. T. Batista, H. Takahashi, V. T. Rampinelli Jan 2009

Convection: The Likely Source Of The Medium-Scale Gravity Waves Observed In The Oh Airglow Layer Near Brasilia, Brazil, During The Spreadfex Campaign, Sharon L. Vadas, Michael J. Taylor, Pierre-Dominique Pautet, P. A. Stamus, David C. Fritts, H. L. Liu, F. T. São Sabbos, V. T. Batista, H. Takahashi, V. T. Rampinelli

Publications

Six medium-scale gravity waves (GWs) with horizontal wavelengths of λH=60–160 km were detected on four nights by Taylor et al. (2009) in the OH airglow layer near Brasilia, at 15° S, 47° W, during the Spread F Experiment (SpreadFEx) in Brazil in 2005. We reverse and forward ray trace these GWs to the tropopause and into the thermosphere using a ray trace model which includes thermospheric dissipation. We identify the convective plumes, convective clusters, and convective regions which may have generated these GWs. We find that deep convection is the highly likely source of four of these GWs. We pinpoint …

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Nuclear Resonances: The Quest For Large Column Densities And A New Tool, J. Greiner, S. Boggs, G. Dicocco, K. T. Freese, N. Gehrels, Dieter H. Hartmann, A. Iyudin, G. Kanbach, A. A. Zdziarski Jan 2009

Nuclear Resonances: The Quest For Large Column Densities And A New Tool, J. Greiner, S. Boggs, G. Dicocco, K. T. Freese, N. Gehrels, Dieter H. Hartmann, A. Iyudin, G. Kanbach, A. A. Zdziarski

Publications

Nuclear physics offers us a powerful tool: using nuclear resonance absorption lines to infer the physical conditions in astrophysical settings which are otherwise diffcult to deduce. Present-day technology provides an increase in sensitivity over previous gamma-ray missions large enough to utilize this tool for the first time. The most exciting promise is to measure gamma-ray bursts from the first star(s) at redshifts 20–60, but also active galactic nuclei are promising targets.

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Resources - Thinking Small: Nano Small, David Stricker Jan 2009

Resources - Thinking Small: Nano Small, David Stricker

Publications

The article provides information on the "Nanooze" magazine publication. It notes the significance of nanotechnology to the development of latest innovations that come from materials at smallest dimensions or at the nanoscale levels. It presents resources published within the publication that explore the emerging issues in nanotechnology.

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Analyzing The Impact Of A Virtual Machine On A Host Machine, Greg Dorn, Chris Marberry, Scott Conrad, Philip Craiger Jan 2009

Analyzing The Impact Of A Virtual Machine On A Host Machine, Greg Dorn, Chris Marberry, Scott Conrad, Philip Craiger

Publications

As virtualization becomes more prevalent in the enterprise and in personal computing, there is a great need to understand the technology as well as its ramifications for recovering digital evidence. This paper focuses on trace evidence related to the installation and execution of virtual machines (VMs) on a host machine. It provides useful information regarding the types and locations of files installed by VM applications, the processes created by running VMs and the structure and identity of VMs, ancillary files and associated artifacts.

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Cycle Equivalence Of Graph Dynamical Systems, Matthew Macauley, Henning S. Mortveit Jan 2009

Cycle Equivalence Of Graph Dynamical Systems, Matthew Macauley, Henning S. Mortveit

Publications

Graph dynamical systems (GDSs) generalize concepts such as cellular automata and Boolean networks and can describe a wide range of distributed, nonlinear phenomena. Two GDSs are cycle equivalent if their periodic orbits are isomorphic as directed graphs, which captures the notion of having comparable long-term dynamics. In this paper, we study cycle equivalence of GDSs in which the vertex functions are applied sequentially through an update sequence. The main result is a general characterization of cycle equivalence based on the underlying graph Y and the update sequences. We construct and analyse two graphs C(Y) and D( …

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Book Review: Cyber Security And Global Information Assurance: Threat Analysis And Response Solutions, Gary C. Kessler Jan 2009

Book Review: Cyber Security And Global Information Assurance: Threat Analysis And Response Solutions, Gary C. Kessler

Publications

This document is Dr. Kessler's review of Cyber Security and Global Information Assurance: Threat Analysis and Response Solutions, edited by Kenneth J. Knapp. Information Science Reference, 2009. ISBN: 978-1-60566-326-5.

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Book Review: Escaping The Bonds Of Earth: The Fifties And The Sixties, T. D. Oswalt Jan 2009

Book Review: Escaping The Bonds Of Earth: The Fifties And The Sixties, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of by Ben Evans. Springer/Praxis, 2009 493p, 9780387790930 $39.95

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Book Review: Humans In Outer Space-Interdisciplinary Odysseys, Studies In Space Policy, 1, T. D. Oswalt Jan 2009

Book Review: Humans In Outer Space-Interdisciplinary Odysseys, Studies In Space Policy, 1, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of Humans in Outer Space-Interdisciplinary Odysseys, Studies in Space Policy, 1. [ed.] by Luca Codignola and Kai-Uwe Schrogl with Agnieszka Lukaszczyk and Nicolas Peter SpringerWeinNewYork, 2009

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Invited Article: Data Analysis Of The Floating Potential Measurement Unit Aboard The International Space Station, Aroh Barjatya, Charles M. Swenson, Donald C. Thompson, Kenneth H. Wright Jan 2009

Invited Article: Data Analysis Of The Floating Potential Measurement Unit Aboard The International Space Station, Aroh Barjatya, Charles M. Swenson, Donald C. Thompson, Kenneth H. Wright

Publications

We present data from the Floating Potential Measurement Unit (FPMU) that is deployed on the starboard truss of the International Space Station. The FPMU is a suite of instruments capable of redundant measurements of various plasma parameters. The instrument suite consists of a floating potential probe, a wide-sweeping spherical Langmuir probe, a narrow-sweeping cylindrical Langmuir probe, and a plasma impedance probe. This paper gives a brief overview of the instrumentation and the received data quality, and then presents the algorithm used to reduce I-V curves to plasma parameters. Several hours of data are presented from August 5, 2006 and March …

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Statistical Analysis Of Stellar Evolution, David A. Van Dyk, Ted Von Hippel, Steven Degenarro, Nathan Stein, William Jefferys Jan 2009

Statistical Analysis Of Stellar Evolution, David A. Van Dyk, Ted Von Hippel, Steven Degenarro, Nathan Stein, William Jefferys

Publications

Color-Magnitude Diagrams (CMDs) are plots that compare the magnitudes (luminosities) of stars in different wavelengths of light (colors). High nonlinear correlations among the mass, color, and surface temperature of newly formed stars induce a long narrow curved point cloud in a CMD known as the main sequence. Aging stars form new CMD groups of red giants and white dwarfs. The physical processes that govern this evolution can be described with mathematical models and explored using complex computer models. These calculations are designed to predict the plotted magnitudes as a function of parameters of scientific interest, such as stellar age, mass, …

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Interaction Of Tollmien-Schlichting Waves In The Air With The Sea Surface, Shahrdad G. Sajjadi, Harihar Khanal Jan 2009

Interaction Of Tollmien-Schlichting Waves In The Air With The Sea Surface, Shahrdad G. Sajjadi, Harihar Khanal

Publications

No abstract provided.

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On Nonlinear Generalizations Of The Kdv And Bbm Equations From Long Range Water Wave Theory, Timothy A. Smith Jan 2009

On Nonlinear Generalizations Of The Kdv And Bbm Equations From Long Range Water Wave Theory, Timothy A. Smith

Publications

A generalization of the famous KdV and BBM equation are considered with a new nonlinear term. Sufficient conditions of solvability, existence and uniqueness are established.

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Singular Superposition/Boundary Element Method For Reconstruction Of Multi-Dimensional Heat Flux Distributions With Application To Film Cooling Holes, Mahmood Silieti, Eduardo Divo, Alain J. Kassab Jan 2009

Singular Superposition/Boundary Element Method For Reconstruction Of Multi-Dimensional Heat Flux Distributions With Application To Film Cooling Holes, Mahmood Silieti, Eduardo Divo, Alain J. Kassab

Publications

A hybrid singularity superposition/boundary element-based inverse problem method for the reconstruction of multi-dimensional heat flux distributions is developed. Cauchy conditions are imposed at exposed surfaces that are readily reached for measurements while convective boundary conditions are unknown at surfaces that are not amenable to measurements such as the walls of the cooling holes. The purpose of the inverse analysis is to determine the heat flux distribution along cooling hole surfaces. This is accomplished in an iterative process by distributing a set of singularities (sinks) inside the physical boundaries of the cooling hole (usually along cooling hole centerline) with a given …

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Gravitational Wave Burst Source Direction Estimation Using Time And Amplitude Information, J. Markowitz, M. Zanolin, L. Cadonati, E. Katsavounidis Dec 2008

Gravitational Wave Burst Source Direction Estimation Using Time And Amplitude Information, J. Markowitz, M. Zanolin, L. Cadonati, E. Katsavounidis

Publications

In this article we study two problems that arise when using timing and amplitude estimates from a network of interferometers (IFOs) to evaluate the direction of an incident gravitational wave burst (GWB). First, we discuss an angular bias in the least squares timing-based approach that becomes increasingly relevant for moderate to low signal-to-noise ratios. We show how estimates of the arrival time uncertainties in each detector can be used to correct this bias. We also introduce a stand alone parameter estimation algorithm that can improve the arrival time estimation and provide root-sum-squared strain amplitude (h(rss)) values for each site. In …

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A Performance And Productivity Study Using Mpi, Titanium, And Fortress, Amy Apon, Chris Bryan, Wesley Emeneker Dec 2008

A Performance And Productivity Study Using Mpi, Titanium, And Fortress, Amy Apon, Chris Bryan, Wesley Emeneker

Publications

The popularity of cluster computing has increased focus on usability, especially in the area of programmability. Languages and libraries that require explicit message passing have been the standard. New languages, designed for cluster computing, are coming to the forefront as a way to simplify parallel programming. Titanium and Fortress are examples of this new class of programming paradigms. This papers presents results from a productivity study of these two newcomers with MPI, the de- facto standard for parallel programming.

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Magnetohydrodynamic Effects In Propagating Relativistic Jets: Reverse Shock And Magnetic Acceleration, Yosuke Mizuno, Bing Zhang, Bruno Giacomazzo, Ken-Ichi Nishikawa, Phillip E. Hardee, Shigehiro Nagataki, Dieter H. Hartmann Dec 2008

Magnetohydrodynamic Effects In Propagating Relativistic Jets: Reverse Shock And Magnetic Acceleration, Yosuke Mizuno, Bing Zhang, Bruno Giacomazzo, Ken-Ichi Nishikawa, Phillip E. Hardee, Shigehiro Nagataki, Dieter H. Hartmann

Publications

We solve the Riemann problem for the deceleration of an arbitrarily magne-tized relativistic flow injected into a static unmagnetized medium in one dimen-sion. We find that for the same initial Lorentz factor, the reverse shock becomes progressively weaker with increasing magnetization σ (the Poynting-to-kinetic energy flux ratio), and the shock becomes a rarefaction wave when σ exceeds a critical value, σc, defined by the balance between the magnetic pressure in the flow and the thermal pressure in the forward shock. In the rarefaction wave regime, we find that the rarefied region is accelerated to a Lorentz factor that is significantly …

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A Three-Dimensional Pattern-Space Representation For Volumetric Arrays, William C. Barott, Paul G. Steffes Dec 2008

A Three-Dimensional Pattern-Space Representation For Volumetric Arrays, William C. Barott, Paul G. Steffes

Publications

A three-dimensional pattern-space representation is presented for volumetric arrays. In this representation, the radiation pattern of an array is formed by the evaluation of the three-dimensional pattern-space on a spherical surface. The scan angle of the array determines the position of this surface within the pattern-space. This pattern-space representation is used in conjunction with a genetic algorithm to minimize the sidelobe levels exhibited by a thinned volumetric array during scanning.

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Geocoronal Hydrogen Observations Spanning Three Solar Minima, S. M. Nossal, E. J. Mierkiewicz, F. L. Roesler, L. M. Haffner, R. J. Reynolds, R. C. Woodward Nov 2008

Geocoronal Hydrogen Observations Spanning Three Solar Minima, S. M. Nossal, E. J. Mierkiewicz, F. L. Roesler, L. M. Haffner, R. J. Reynolds, R. C. Woodward

Publications

The 11-year solar cycle is a dominant source of natural variability in the upper atmosphere, and its effect on atomic hydrogen distributions and emissions must be understood to investigate possible signs of longer-term climatic trends in this region. We present midlatitude geocoronal hydrogen Balmer α observations from solar cycle 23 (1997–2006) and three solar minimum periods, 1985, 1997, and 2006. The 1997 through 2006 observations were taken with the Wisconsin H-αMapper Fabry-Perot (WHAM), a ground-based CCD-annular summing instrument that began observations at the Kitt Peak Observatory in Arizona in 1997. The 1985 observations were made with a similarly …

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Multicolor Conjugated Polymer Dots For Biological Fluorescence Imaging, Changfeng Wu, Barbara Bull, Craig Szymanski, Kenneth Christensen, Jason Mcneill Nov 2008

Multicolor Conjugated Polymer Dots For Biological Fluorescence Imaging, Changfeng Wu, Barbara Bull, Craig Szymanski, Kenneth Christensen, Jason Mcneill

Publications

Highly fluorescent conjugated polymer dots were developed for demanding applications such as fluorescence imaging in live cells. These nanoparticles exhibit small particle diameters, extraordinary fluorescence brightness, and excellent photostability. Single particle fluorescence imaging and kinetic studies indicate much higher emission rates (∼108 s−1) and little or no blinking of the nanoparticles as compared to typical results for single dye molecules and quantum dots. Analysis of single particle photobleaching trajectories reveals excellent photostability—as many as 109 or more photons emitted per nanoparticle prior to irreversible photobleaching. The superior figures of merit of these new fluorescent probes, together …

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Multiwavelength Analysis Of The Intriguing Grb 061126: The Reverse Shock Scenario And Magnetization, A. Gomboc, S. Kobayashi, C. Guidorzi, A. Melandri, V. Mangano, B. Sbarufatti, C. G. Mundell, P. Schady, R. J. Smith, A C. Updike, D A. Kann, K Misra, E Rol, A Pozanenko, A J. Castro-Tirado, G C. Anupama, D Bersier, M F. Bode, D Carter, P Curran, A Fruchter, J Graham, Dieter H. Hartmann, M Ibrahimov, A Levan, A Monfardini, C J. Mottram, P T. O'Brien, P Prema, D K. Sahu, I A. Steele, N R. Tanvir, K Wiersema Nov 2008

Multiwavelength Analysis Of The Intriguing Grb 061126: The Reverse Shock Scenario And Magnetization, A. Gomboc, S. Kobayashi, C. Guidorzi, A. Melandri, V. Mangano, B. Sbarufatti, C. G. Mundell, P. Schady, R. J. Smith, A C. Updike, D A. Kann, K Misra, E Rol, A Pozanenko, A J. Castro-Tirado, G C. Anupama, D Bersier, M F. Bode, D Carter, P Curran, A Fruchter, J Graham, Dieter H. Hartmann, M Ibrahimov, A Levan, A Monfardini, C J. Mottram, P T. O'Brien, P Prema, D K. Sahu, I A. Steele, N R. Tanvir, K Wiersema

Publications

We present a detailed study of the prompt and afterglow emission from Swift GRB 061126 using BAT, XRT, UVOT data and multicolor optical imaging from 10 ground-based telescopes. GRB 061126 was a long burst (T90 ¼191 s) with four overlapping peaks in its -ray light curve. The X-ray afterglow, observed from 26 minutes to 20 days after the burst, shows a simple power-law decay with X ¼1:290 Æ0:008. Optical observations presented here cover the time range from 258 s (Faulkes Telescope North) to 15 days (Gemini North) after the burst; the decay rate of the optical afterglow shows a steep-to-shallow …

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