The LOng Range Reconnaissance Imager (LORRI) is a panchromatic (360-910 nm for the wavelengths where the responsivity falls to 10% of the peak value), narrow-angle (field of view = 0 29), high ...spatial resolution (pixel scale = 1 02) visible light imager used on NASA's New Horizons (NH) mission for both science observations and optical navigation. Calibration observations began several months after the New Horizons launch on 2006 January 19 and have been repeated approximately annually throughout the course of the mission, which is ongoing. This paper describes the in-flight LORRI calibration measurements, and the results derived from our analysis of the calibration data. LORRI has been remarkably stable over time with no detectable changes (at the ∼1% level) in sensitivity or optical performance since launch. The point-spread function varies over the FOV but is well-characterized and stable, enabling accurate deconvolution to recover the highest possible spatial resolution during observations of resolved targets, especially when multiple, overlapping images are obtained. By employing 4 × 4 re-binning of the CCD pixels during read out, a special spacecraft tracking mode, exposure times of ∼30 s, and co-addition of ∼100 images, LORRI can detect unresolved targets down to V 22 with a signal-to-noise ratio (S/N) of ∼5. LORRI images have an instantaneous dynamic range of ∼3500, which combined with exposure time control ranging from 0 ms to 64,967 ms in 1 ms steps supports high resolution, high sensitivity imaging of planetary targets spanning heliocentric distances from Jupiter to deep in the Kuiper Belt, enabling a wide variety of scientific investigations. We describe here how to transform LORRI images from raw (engineering) units into scientific (calibrated) units for both resolved and unresolved targets. Assuming that the wavelength variation of LORRI's sensitivity is accurately described by the ground-based calibration, we estimate that LORRI's absolute sensitivity is accurate to ∼2% (1 ) for targets with solar-type spectral energy distributions (SEDs). The accuracy of the absolute calibration for targets with other SEDs should be comparably good when employing synthetic photometry techniques, which we do when deriving LORRI's photometry keywords. We also describe various instrumental artifacts that could affect the interpretation of LORRI images under some observing circumstances.
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NASA's Interstellar Boundary Explorer (IBEX) mission was recently maneuvered into a unique long‐term stable Earth orbit, with apogee at ∼50 Earth radii (RE). The Moon's (∼65 RE) gravity disrupts most ...highly elliptical Earth orbits, leading to (1) chaotic orbital solutions, (2) the inability to predict orbital positions more than a few years into the future, and ultimately (3) mission‐ending possibilities of atmospheric reentry or escape from Earth orbit. By synchronizing the satellite's orbital period to integer fractions of the Moon's sidereal period, PM = 27.3 days (e.g., PM/2 = 13.6 days, PM/3 = 9.1 days), and phasing apogee to stay away from the Moon, very long term stability can be achieved. Our analysis indicates orbital stability for well over a decade, and these IBEX‐like orbits represent a new class of Earth orbits that are stable far longer than typical satellite lifetimes. These orbits provide cost‐effective and nearly ideal locations for long‐term space weather observations from spacecraft that can remotely image the Earth's magnetosphere from outside its boundaries while simultaneously providing external (solar wind or magnetosheath) observation over most of their orbits. Utilized with multiple spacecraft, such orbits would allow continuous and simultaneous monitoring of the magnetosphere in order to help predict and mitigate adverse space weather–driven effects.
Key Points
IBEX is currently flying in a new, long‐term stable lunar resonant orbit
Lunar resonance orbits would be excellent for space weather missions
IBEX has already demonstrated new magnetospheric ENA imaging capabilities
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The New Horizons mission was launched on 2006 January 19, and the spacecraft is heading for a flyby encounter with the Pluto system in the summer of 2015. The challenges associated with sending a ...spacecraft to Pluto in less than 10 years and performing an ambitious suite of scientific investigations at such large heliocentric distances (>32 AU) are formidable and required the development of lightweight, low power, and highly sensitive instruments. This paper provides an overview of the New Horizons science payload, which is comprised of seven instruments.
Alice
provides moderate resolution (∼3–10 Å FWHM), spatially resolved ultraviolet (∼465–1880 Å) spectroscopy, and includes the ability to perform stellar and solar occultation measurements. The
Ralph
instrument has two components: the
Multicolor Visible Imaging Camera (MVIC)
, which performs panchromatic (400–975 nm) and color imaging in four spectral bands (Blue, Red, CH
4
, and NIR) at a moderate spatial resolution of 20 μrad/pixel, and the
Linear Etalon Imaging Spectral Array (LEISA)
, which provides spatially resolved (62 μrad/pixel), near-infrared (1.25–2.5 μm), moderate resolution (
λ
/
δ
λ
∼240–550) spectroscopic mapping capabilities. The
Radio Experiment (REX)
is a component of the New Horizons telecommunications system that provides both radio (X-band) solar occultation and radiometry capabilities. The
Long Range Reconnaissance Imager (LORRI)
provides high sensitivity (
V
<18), high spatial resolution (5 μrad/pixel) panchromatic optical (350–850 nm) imaging capabilities that serve both scientific and optical navigation requirements. The
Solar Wind at Pluto (SWAP)
instrument measures the density and speed of solar wind particles with a resolution Δ
E
/
E
<0.4 for energies between 25 eV and 7.5 keV. The
Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI)
measures energetic particles (protons and CNO ions) in 12 energy channels spanning 1–1000 keV. Finally, an instrument designed and built by students, the
Venetia Burney
Student Dust Counter (VB-SDC)
, uses polarized polyvinylidene fluoride panels to record dust particle impacts during the cruise phases of the mission.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
OBJECTIVESAdolescents are at greater risk for acquiring human immunodeficiency virus (HIV) due to increased risk behaviors. Parental influence is known to reduce adolescent risk behaviors. We ...compared HIV risk behaviors reported by adolescents to parentsʼ perception of adolescent risky behavior engagement. We also examined participantsʼ knowledge of HIV transmission and testing preferences.
METHODSParticipants included English-speaking adolescents and parents presenting to a pediatric emergency department. Participants were interviewed separately in private. Modeled after existing instruments, “adolescent” and “parent” questionnaires included multiple choices items, Likert-type scales, and standard yes/no and true/false options. Data were analyzed using a κ statistic and observed agreement to measure discordance between adolescent and parent responses.
RESULTSParticipants included 126 adolescents and 110 parents. Many adolescents reported ever having sex (61%), of which 32% reported always practicing safe sex. Comparative analysis revealed low agreement between adolescentsʼ risk behaviors and parentsʼ perception of risk behavior engagement by youth. Discordance concerning tobacco use was greatest (κ = 0.13), followed by drug use (κ = 0.19) and ever having sex (κ= 0.19), and alcohol use (κ= 0.22). There was also poor agreement regarding HIV transmission knowledge (ie, oral sex; κ = 0.16). Participants shared strong agreement regarding parental support for adolescent interest in HIV testing (95.5%).
CONCLUSIONSParents are mostly unaware of adolescentsʼ broad risk behaviors. Participantsʼ knowledge of HIV transmission is limited. Adolescents and parents shared strong agreement regarding HIV testing preferences. Multidimensional HIV prevention strategies aiming to decrease adolescent risk behaviors, increase parental involvement, and improve adolescent and parental knowledge of HIV transmission are needed.
The synthesis and SAR of a novel, rationally designed series of benzimidazole TPO receptor agonists are reported.
A novel benzimidazole series of small-molecule thrombopoietin receptor agonists has ...been discovered. Herein, we discuss the preliminary exploration of structure–activity relationships within this chemotype.
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6.
The IBEX Flight Segment Scherrer, J.; Carrico, J.; Crock, J. ...
Space science reviews,
08/2009, Volume:
146, Issue:
1-4
Journal Article
Peer reviewed
IBEX provides the observations needed for detailed modeling and in-depth understanding of the interstellar interaction (McComas et al. in Physics of the Outer Heliosphere, Third Annual IGPP ...Conference, pp. 162–181,
2004
; Space Sci. Rev.,
2009a
, this issue). From mission design to launch and acquisition, this goal drove all flight system development. This paper describes the management, design, testing and integration of IBEX’s flight system, which successfully launched from Kwajalein Atoll on October 19, 2008. The payload is supported by a simple, Sun-pointing, spin-stabilized spacecraft with no deployables. The spacecraft bus consists of the following subsystems: attitude control, command and data handling, electrical power, hydrazine propulsion, RF, thermal, and structures. A novel 3-step orbit approach was employed to put IBEX in its highly elliptical, 8-day final orbit using a Solid Rocket Motor, which provided large delta-V after IBEX separated from the Pegasus launch vehicle; an adapter cone, which interfaced between the SRM and Pegasus; Motorized Lightbands, which performed separation from the Pegasus, ejection of the adapter cone, and separation of the spent SRM from the spacecraft; a ShockRing isolation system to lower expected launch loads; and the onboard Hydrazine Propulsion System. After orbit raising, IBEX transitioned from commissioning to nominal operations and science acquisition. At every phase of development, the Systems Engineering and Mission Assurance teams supervised the design, testing and integration of all IBEX flight elements.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The LOng Range Reconnaissance Imager (LORRI) is a panchromatic (360–910 nm for the wavelengths where the responsivity falls to 10% of the peak value), narrow-angle (field of view = 0°.29), high ...spatial resolution (pixel scale = 1″.02) visible light imager used on NASA’s New Horizons (NH) mission for both science observations and optical navigation. Calibration observations began several months after the New Horizons launch on 2006 January 19 and have been repeated approximately annually throughout the course of the mission, which is ongoing. This paper describes the in-flight LORRI calibration measurements, and the results derived from our analysis of the calibration data. LORRI has been remarkably stable over time with no detectable changes (at the ∼1% level) in sensitivity or optical performance since launch. The point-spread function varies over the FOV but is well-characterized and stable, enabling accurate deconvolution to recover the highest possible spatial resolution during observations of resolved targets, especially when multiple, overlapping images are obtained. By employing 4 × 4 re-binning of the CCD pixels during read out, a special spacecraft tracking mode, exposure times of ∼30 s, and coaddition of ∼100 images, LORRI can detect unresolved targets down to V ≈ 22 with a signal-to-noise ratio (S/N) of ∼5. LORRI images have an instantaneous dynamic range of ∼3500, which combined with exposure time control ranging from 0 ms to 64,967 ms in 1 ms steps supports high resolution, high sensitivity imaging of planetary targets spanning heliocentric distances from Jupiter to deep in the Kuiper Belt, enabling a wide variety of scientific investigations. We describe here how to transform LORRI images from raw (engineering) units into scientific (calibrated) units for both resolved and unresolved targets. Assuming that the wavelength variation of LORRI’s sensitivity is accurately described by the ground-based calibration, we estimate that LORRI’s absolute sensitivity is accurate to ∼2% (1σ) for targets with solar-type spectral energy distributions (SEDs). The accuracy of the absolute calibration for targets with other SEDs should be comparably good when employing synthetic photometry techniques, which we do when deriving LORRI’s photometry keywords. We also describe various instrumental artifacts that could affect the interpretation of LORRI images under some observing circumstances.
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The human T cell-derived cytokines interleukin (IL)-3, granulocyte-macrophage colony-stimulating factor (GM-CSF), and IL-5 were examined for their ability to bind specifically to human basophils and ...to regulate their function. Scatchard analysis of equilibrium binding studies showed that IL-3 and GM-CSF, bound to basophils with apparent dissociation constants (KD) = 8 x 10(-11) M and 3.9 x 10(-11) M, respectively. Specificity studies under conditions that prevent receptor internalization showed that the binding of IL-3, GM-CSF, and IL-5 was not inhibited by tumor necrosis factor (TNF)-alpha, IL-1 beta, interferon (IFN)-gamma, or G-CSF. However, receptors for IL-3, GM-CSF, and IL-5 interacted with each other on the basophil membrane, showing a unique spectrum of cross-reactivity, with IL-3 competing for GM-CSF and IL-5 binding, whereas GM-CSF and IL-5 showed little or no competition for IL-3 binding. In order to relate the binding properties of these cytokines to function, they were tested for their ability to influence basophil histamine release in an IgE/anti-IgE-dependent system. We found a hierarchy in the stimulation of basophil with the order of potency being IL-3 greater than GM-CSF greater than IL-5. In addition, IL-3 stimulated larger amounts of histamine release than GM-CSF or IL-5. The observation that IL-3 interacts with receptors for GM-CSF and IL-5 may have a bearing on its stronger functional effects and suggests a major role for IL-3 in the pathogenesis of hypersensitivity syndromes.
A group performance test of handedness was administered to 1556 undergraduates. This test required subjects to place dots in circles as rapidly as possible. The test was found to be reliable, and to ...correlate with hand preference. Both hand performance and hand preference measures are skewed in the population as a whole, but the distributions can be adequately fitted by two normal curves, one with a right bias and one with a left bias. These findings suggest that left-handers are a distinct subgroup of the population.
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